rccl - review of cornea & contact lenses · following cataract surgery,” eric donnenfeld, md,...

Outdated FDA protocols don’t account for real-world usage, newer lens materials and virulent organisms. Proposed updates could bring big changes.

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FEBRUARY 2016

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RCCLRCCLREVIEW OF CORNEA & CONTACT LENSES

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contentsReview of Cornea & Contact Lenses | February 2016

/ReviewofCorneaAndContactLenses #rcclmag

departments

12Putting it On the Map: Fitting Rigid Lenses Using Corneal TopographyFamiliarizing yourself with corneal mapping can lead to more success with your contact lens patients. By Vivian Phan Shibayama, OD

18Forward Thinking: Where Can New Lenses Lead Your Practice?From sclerals to daily disposables and tinted lenses, new designs can add to your practice if you’re willing to change your mindset. By Jane Cole, Contributing Editor

28CE — Reality Check: How FDA Testing Falls ShortOutdated FDA protocols don’t account for real-world us-age, newer lens materials and virulent organisms. Pro-posed updates could bring big changes.By Yvonne Tzu-Ying Wu, PhD, MPH, An Truong,

B.Optom, and Fiona Stapleton, PhD

News Review4Lipid-binding Diff erences Noted;

Corneal Diameter Aff ects

Postoperative Astigmatism

My Perspective 6This Year, Strive to Avoid Stress

By Joseph P. Shovlin, OD

Practice Progress8 Solution Savers

By Mile Brujic, OD, and Jason R. Miller, OD, MBA

The Case of the Finicky Fungus

By J. James Thimons, OD

The GP Experts38

Corneal Consult10

Good Chemistry

By Robert Ensley, OD, and Heidi Miller, OD

features

Dextenza on Deck

By Elyse L. Chaglasian, OD, and Tammy Than, MS, OD

Pharma Science & Practice40

Cover design by Ashley Schmouder©iStock.com/Jobsonhealthcare

REVIEW OF CORNEA & CONTACT LENSES | FEBRUARY 2016 3

22Artifi cial Tears: Looking Beneath the SurfaceThese seemingly simple drops are more complex than you think. Do you know what’s in them?By Mike Christensen, OD, PhD,

and Tressa Larson, OD

What’s In a Name?

By Gary Gerber, OD

Out of the Box42

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4 REVIEW OF CORNEA & CONTACT LENSES | FEBRUARY 2016

News Review

Lipid-binding Diff erences Noted

Deposition of cholesterol on contact lenses varies signifi cantly between lens materials, reports a study

in the January 2016 Optometry and Vision Science.1 Though silicone hydrogel (SH) materials are known to increase oxygen transport to the ocular surface, certain chemical components within these materials may also negatively impact wettabil-ity (and potentially patient comfort) if exposed to very high levels of lipids.2-4 To date, however, no study has investigated the degree to which daily disposable lenses uptake lip-ids—in particular, cholesterol.

Researchers at the University of Waterloo in Canada incubated three SH materials and four convention-al hydrogel (CH) materials in an artifi cial tear solution containing radioactive C-labeled cholesterol. Each was submerged for two, six, 12 and 16 hours to simulate typical daily disposable lens wear times.

Results indicated both contact lens type and length of incubation were factors in the amount of cho-lesterol deposition. No signifi cant difference in the amount deposited on the SH materials was observed; a difference did exist among the CH materials. Overall, however, SH materials deposited more cholesterol than CH materials.

These results suggest a number of things, the authors say. First, daily

disposable patients who exhibit rel-atively heavy levels of lipids in their tears due to factors such as meibo-mian gland dysfunction may benefi t from certain CH lens types, such as nelfi lcon A and etafi lcon A mate-rials. Additionally, wearers who require higher oxygen transport but exhibit oily tears should be aware of potential wetting issues when wearing SH daily disposable lenses. However, the researchers point out that further study is needed to deter-mine if the lipid profi les in question are in fact detrimental to lens wear, given their very low levels.

Other caveats: this study only considered one lipid type, choles-terol (many others are found in the tear fi lm); the deposition of certain lipids could be benefi cial to lens wear (as previously reported by the same group); and the amount of lipid deposited may not be as im-portant as whether the lipids under investigation are oxidized or remain in their natural state.5 RCCL 1. Walther H, Subbarman L, Jones LW. In vitro cho-lesterol deposition on daily disposable contact lens materials. Optom Vis Sci. 2016 Jan;93(1):36-41.2. Jones L, Subbarman LN, Rogers R, Dumbleton K.Surface treatment, wetting and modulus of silicone hydrogels. Optician. 2006;232:28-34.3. Maldonado-Codina C, Morgan PB. In vitro water wettability of silicone hydrogel contact lenses de-termined using the sessile drop and captive bubble techniques. J Biomed Mater Res A. 2007;83:496-502.4. Read ML, Morgan PB, Kelly JM. Maldonado-Codina C. Dynamic contact angle analysis of silicone hydro-gel contact lenses. J Biomater Appl. 2011:26:85-99.5. Lorentz H, Rogers R Jones L. The impact of lipid on contact angle wettability. Optom Vis Sci. 2007; 84;10: 946-53.

IN BRIEF

■ Researchers from the University of Missouri School of Medicine have identifi ed a link between adminis-tration of the varicella zoster virus

vaccine for chickenpox and shingles and presentation of keratitis.1 Though the potential for corneal infl ammation as a side eff ect of the vaccine is low, primary care physicians should inform

all patients prior to administration, the researchers say.1. Fraunfelder RW. Varicella zoster vaccine-as-sociated keratitis. Paper presented at American Academy of Ophthalmology, Nov. 16, 2015; Las Vegas, NV.

■ Consider reinforcing orthokeratol-

ogy education, particularly for male patients, reports a study in the January 2016 issue of Eye & Contact Lens.1 Re-searchers in southern Taiwan identifi ed a total of 86 microbial strains from 38 culture-positive specimens taken from orthokeratology lens case fl uids of 41 pediatric wearers. Interestingly, frequently reported pathogens (i.e., Serratia marcescens, Pseudomonas aeruginosa and Staphyloccocus au-reus) in contact-lens related microbial keratitis were identifi ed less commonly in this study; additionally, the lens cas-es of male subjects exhibited a higher

microbial bioburden than those of female subjects. 1. Lo J, Kuo M, Chien C, et al. Microbial bioburden of orthokeratology contact lens care system. Eye & Contact Lens. 2016 Jan;42(1):61-7.

■ A comparison of femtosecond

laser-assisted LASIK and small-in-

cision lenticule extraction (SMILE), published in the February 2016 issue of Cornea, suggests both procedures achieve similar good visual outcomes in the correction of myopia and myo-pic astigmatism; however, patients who underwent SMILE exhibited a lower

induction rate of spherical aberration six months postoperatively, suggesting long-term outcomes of the procedure may ultimately be more benefi cial.1 However, further research is needed based on a larger sample size to con-fi rm this.1. Liu M, Chen Y, Wang D, et al. Clinical outcomes after SMILE and femtosecond laser-assisted LASIK for myopia and myopic astigmatism: a pro-spective randomized comparative study. Cornea. 2016 Feb;35(2):210-6.

■ Menicon America has announced FDA approval for its LacriPure non-preserved saline for rinsing both

soft and rigid lenses. Packaged in 5ml unit-dose vials, the saline is also ap-proved as a fi rst-of-its-kind scleral lens

insertion solution as an alternative to irrigation saline, according to Menicon.

SPEED Questionnaire Vetted

The Standard Patient Evaluation of Eye Dryness (SPEED) questionnaire is comparable to the Ocular Surface Disease Index (OSDI) questionnaire for separating asymptomatic and symptomatic dry eye patients, reports a study published in the February 2016 issue of Cornea.1 Investigators compared the answers of 657 undergraduate students at the Uni-versity of Cape Coast in Ghana, determining the internal consistencies of the OSDI and SPEED questionnaires to be approximately the same (i.e., 0.897 and 0.895, respectively). However, the SPEED questionnaire was relatively better in terms of internal consistency compared with the OSDI questionnaire, indicating it is a valid measure for dry eye and could be used in epidemiological studies and clinical practice, the researchers say.1. Asiedu K, Kyei S, Mensah SN, et al. Ocular surface disease index (OSDI) versus the standard patient evaluation of eye dryness (SPEED): a study of a nonclinical sample. Cornea. 2016 Feb;35(2):175-80.

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Corneal Diameter Aff ects Postoperative Astigmatism

Corneal diameter should be determined prior to cataract surgery, as it can lead to varying degrees of

corneal astigmatism depending on the type of incision used, reports a study in the January 2016 issue of Cornea.1 Other factors already known to impact postoperative astigmatism include incision size, confi guration and location rela-tive to the limbus, as well as the axis on which the main incision is performed.

Researchers observed cataract procedures performed on 330 eyes at the General Hospital of Piraeus “Tzaneio” Attiki in Greece from February 2011 to October 2013. Patients were divided into four groups according to corneal horizontal diameter, i.e., white-to-white (WTW) distance: group A ≤ 11.6mm; group B 11.7mm to 11.9mm; group C 12.0mm to 12.2mm; and group D ≥ 12.3mm. At the fi rst postoperative month, surgically-induced astigmatism (SIA) was 0.98D ± 0.6SD in group A, 0.79D ± 0.43SD in group B, 0.68D ± 0.45SD in group C and 0.53D ± 0.32SD in group D, while at six months postoperatively, SIA was 0.77D ± 0.43SD in group A, 0.69D ± 0.34SD in group B, 0.62D ± 0.36SD in group C and 0.49D ± 0.27SD in group D.

These data indicate that a change greater than 0.5D in corneal astigmatic power at the fi rst and sixth months postoperatively was signifi cantly lower in eyes with WTW distance 12.0mm to 12.2mm and ≥ 12.3mm, compared with eyes with WTW distance ≤ 11.6mm and 11.7mm to 11.9mm. In effect, the

researchers note, the smaller the cornea, the larger the effect on the power of postoperative astigmatism.

“These fi ndings are important because it identifi es an additional perioperative variable that is helpful in improving astigmatic results following cataract surgery,” Eric Donnenfeld, MD, a surgeon on Long Island, says.

Researchers also classifi ed the participating eyes into groups of either right or left to evaluate if superior and superomedial incisions in the left eyes lead to greater SIA due to the primary incision being situated closer to the optical center of the cornea and the placement of the phaco probe against the nose and brow. They also examined whether superior and superolateral incisions produce more postopera-tive astigmatism in against-the-rule astigmatic eyes than in with-the-rule eyes.

Ultimately, however, results indi-cated no differences in SIA between right and left eyes, and the type of astigmatism could not be account-ed for, due to the unvaried patient base. The results are further limited by the evaluation of anterior surface topography, the researchers note. Research that includes posterior corneal effects is needed to more fully evaluate astigmatism-induced results. RCCL

1. Theodoulidou S, Asproudis I, Kalogeropoulos C, et al. Corneal diameter as a factor infl uencing corneal astigmatism after cataract surgery. Cornea. 2016 Jan;35(1):132-6.

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EDITORIAL REVIEW BOARD

Mark B. Abelson, MD

James V. Aquavella, MD

Edward S. Bennett, OD

Aaron Bronner, OD

Brian Chou, OD

Kenneth Daniels, OD

S. Barry Eiden, OD

Desmond Fonn, Dip Optom M Optom

Gary Gerber, OD

Robert M. Grohe, OD

Susan Gromacki, OD

Patricia Keech, OD

Bruce Koffler, MD

Pete Kollbaum, OD, PhD

Jeffrey Charles Krohn, OD

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RCCLRCCLREVIEW OF CORNEA & CONTACT LENSES

Advertiser Index

Alcon ....................................Cover 3

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Menicon .............................. Cover 4

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By Joseph P. Shovlin, OD

My Perspective


This Year, Strive to Avoid StressIf you are like most of us, decreasing tension in 2016 is a laudable New Year’s resolution.

Many of us in prac-tice—especially for 10 years or more— know all too well how stress

can lead to some amount of professional “burnout.” It has a pervasive effect on nearly every action we perform daily, from the degree of care we provide our patients to our relationships with friends, family and coworkers. Symptoms of burnout include mental and physical exhaustion, stress, depersonalization (i.e., cynicism and sarcasm) and a re-duced sense of accomplishment.1-6

While burnout is common in most industries, it’s on the rise among health care professionals in particular.2

A recent Mayo Clinic study as-sessing the incidence of burnout symptoms, such as work/life im-balance, depression and suicidal ideation among physicians found that 54.4% of those surveyed reported one or more symptoms of burnout in 2014, compared with 45.5% in 2011 (p=0.001).4

With respect to individual symptoms, the rate of physicians with a healthy work/life balance decreased in the three-year span measured, with only 40.9% of practitioners reporting they had suffi cient time for personal and family life in 2014.2,3 Long-term consequences linked to burn-out included: (1) lower patient satisfaction and quality of care; (2) higher medical error rates and risk for malpractice; (3) higher physician and staff turnover; (4) physician alcohol and drug abuse; and (5) physician suicide.4,5

LOW BATTERY

What is causing this epidemic? Mark Linzer, MD, offers a list of specifi c drivers below:5

• Stress. Research has demon-strated you’re 15 times more likely to burn out if you operate under constant stress. Ongoing concern for medical errors and potential malpractice cases also raises stress levels; additionally, payers may ob-struct tests that you deem necessary, limiting your ability to provide the best patient care possible.

• Chaos. Caring for patients is what keeps most doctors motivated, but caring for too many of them under a stressful environment is gen-erally what burns them out. Recent changes imposed by government entities and payers have further heightened the demand.

• Discord. Motivation wanes quickly if your practice ideals and values don’t match, or if a healthy camaraderie does not exist between members of your practice.

• Depersonalization. We of-ten serve as the emotional buffer between the patient and our own environment, sometimes limiting our ability to connect with them. And, after years of practice, things can begin to seem mundane or depersonalized.

• Interference. Leaving insuffi cient room for personal schedule changes and needs in daily life can lead to negative spillover into work life, and vice-versa.

• Neglect. Self-care is critical—when you neglect yourself, you neglect your patients. Taking time to relax to ensure you can focus when needed and provide the best care possible.

PHYSICIAN, HEAL THYSELF

Let’s face it—work is stressful. Indeed, that’s why they call it work. But the difference between manage-able levels of stress and complete professional burnout is the ability to recover when not working.6 Personal downtime is key, and we all need an activity that brings us joy. It is vital that we carve out some time from our workweek to do the things we love.

Research has shown prevention and treatment measures for burn-out should be approached both on the personal and organizational level.6 Personal burnout preven-tion measures involve maintaining self-awareness, appreciative inquiry, narrative medicine and maintain-ing a healthy work/life balance.5,6

Measures that can be taken at the organizational level include the creation of specifi c programs to sup-port health care providers and the allowance for fl exible work hours.

Remember, we have a lot to bring to the battle against

burnout: intelligence, good incomes, support from family and friends and life outside of health care and an overall investment in education and self-growth.6 None of us are im-mune to burnout—make avoiding it your resolution for 2016. RCCL

1. Drummond D. Physician burnout-the three symp-toms, three phases, and three cures. The Happy MD. 2015 Oct.2. Swift D. Physician burnout climbs 10% in 3 years, hits 55%. Medscape; 2015 Dec.3. Peckham C: Physician burnout: It just keeps getting worse. Medscape; Jan, 2015.4. Drummond D. Physician burnout: Its origin, symptoms and fi ve main causes. Family Practice Management, 2015 Sept/Oct;(5):42-7.5. Linzer M. How to beat burnout: 7 signs physicians should know. AMA Wire. 2015 Mar.6. Drummond D. Physician burnout: Why it’s not a fair fi ght. The Happy MD. 2015 Sept.

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By Mile Brujic, OD, and Jason Miller, OD, MBA

Practice Progress

Solution SaversLens care can make or break the contact lens experience for patients.Here’s how to tip the odds in favor of success.

Even as we recognize that the newest contact lens development efforts give us viable options for everyone, includ-

ing our most diffi cult patients, it is important to remember most lenses prescribed today in North America continue to be two-week and monthly disposables, despite the infl ux of daily replacement options. How, as eye care prac-titioners, can we help patients choose the right solution, and how does this help our goal of practice building? Reminding patients—both old and new—of proper contact lens care and solution use is key to maintaining a healthy pa-tient population and even drawing in new ones.

A tremendous amount of re-search documents widespread lack of contact lens compliance, which can signifi cantly affect the patient’s wearing experience.1-3 Although poor hygiene during lens care and handling typically dominates discussions of noncompliance, inattention to lens/solution com-patibility when purchasing care products is also a concern among practitioners.

Patients face the challenge of selecting the right solution for their lenses following the initial fi tting appointment, especially as many multipurpose solutions created decades ago remain packaged similarly to even the most recently engineered products. Intentional mimicry in product design by ge-neric or store-brand products can mislead patients into making poor choices at the drugstore.

KNOW YOUR SOLUTIONS

Biotrue (Bausch + Lomb), OptiFree PureMoist (Alcon) and Revitalens OcuTec (Abbot Medical Optics) are three of the latest additions to the multipurpose solution options. Biotrue contains hyaluronic acid, a glycosaminoglycan that tempo-rarily binds to the surface of the lens to increase daily comfort.5

OptiFree PureMoist contains the copolymer polyoxyethylene-poly-oxybutylene under the trade name HydraGlyde, which is said to im-prove lens surface wettability and end-of-day comfort.6,7 Revitalens OcuTec contains the wetting agent Tetronic 904 in attempts to opti-mize surface moisture.8

Other disinfection options come in the form of hydrogen peroxide systems—most notably ClearCare (Alcon), the newer ClearCare Plus (Alcon) and PerioxiClear (Bausch + Lomb). Overall, peroxide systems have remained the mainstay for individuals with multipurpose solution sensitivities due to the lack of chemical preservatives in the peroxide. For those individuals prone to developing giant papillary conjunctivitis (GPC) who may not be good candidates for daily disposable contact lenses, hydro-gen peroxide disinfection works re-markably well as a solution option after the patient’s GPC has been appropriately managed (Figure 1). And in fact, peroxide systems are having a bit of a renaissance lately, as practitioners see them as a possible bulwark against noncom-pliance. Patients can’t “top off” their solution if using peroxide, for instance.

ClearCare is a one-step peroxide system that combines disinfection and storage capabilities into a single entity. Patients can either rub and rinse the lenses with this solution and then place them in the lens case cage prior to submerging them in the solution, or place the lenses in the cage, rinse them for fi ve seconds and then submerge the entire entity. An overnight soak in ClearCare requires six hours of neutralization prior to lens wear. Alcon recently added HydraGlyde to its ClearCare formulation under the name ClearCare Plus.

PeroxiClear, another one-step peroxide disinfection solution, has a four-hour soak requirement for neutralization. This time frame may be better suited for contact lens wearers with less consistent schedules who may require a faster cleaning method. Disinfection occurs via a platinum-modulating compound known as carbamide: when the platinum disc is sub-merged in peroxide, the carbamide binds to the platinum to inhibit the neutralization rate. This keeps the peroxide at a higher concen-tration than normal (i.e., when not in the presence of carbamide), and increases the total exposure of the lenses to the peroxide.9 During the fi rst 60 minutes of soaking, the carbamide loses its affi nity for the platinum disc, causing the platinum disc to rapidly neutralize the peroxide in the system. This rapid neutralization is what allows wearers to remove the lens from the peroxide solution after only a four-hour soak and comfortably place it on the eye.

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UNDERSTAND

THEIR

DIFFERENCES

New technologies can help create better wearing experiences for the patient—which is why practitioners must remain cogni-zant of the number of store-brand peroxide systems that are also available. While sim-ilar at fi rst to some of the branded systems, they, in fact, have signifi cant differences that can irrevocably al-ter a patient’s wearing experience.

A number of struc-tural differences exist between branded peroxide basket-and-disc systems and generic formulations. In non-branded peroxide solu-tions, the platinum disc is typically located at the bottom of the vial that holds the peroxide rather than attached to the basket that con-tains the lenses. While a seemingly trivial detail, this difference can affect the neutralization profi le of the peroxide: because the platinum disc is attached to the basket con-taining the lenses, both the lenses and platinum disc are submerged into the peroxide simultaneously to provide maximum exposure of the lenses to the peroxide. In contrast, the placement of the platinum disc at the bottom of the vial in store-brand products means that the neutralization process begins as soon as the peroxide is placed in the vial. If a lens wearer

delays placement of their lenses into the basket, the lenses’ to-tal exposure time to peroxide is decreased—effectively lowering disinfection effi cacy. Should the patient insist on using private label peroxide systems, let them know that that the lenses and lens basket should be submerged into the peroxide immediately after the peroxide has been placed in the vial containing the platinum disc.

Giving a little extra attention to contact lens care guidance

means healthier, and thus happier, patients—and happier patients means more referrals. RCCL

1. Tilia D, Lazon de la Jara P, Zhu H, et al. The ef-fect of compliance on contact lens case contami-nation. Optom Vis Sci. 2014 Mar;91(3):262-71.

2. Kuzman T, Kutija MB, Juri J, et al. Lens wearers non-compliance - is there an association with lens case contamination? Cont Lens Anterior Eye. 2014 Apr;37(2):99-105.

3. Dumbleton KA, Woods CA, Jones LW, Fonn D. The relationship between compliance with lens replacement and contact lens-related problems in silicone hydrogel wearers. Cont Lens Anterior Eye. 2011 Oct;34(5):216-22.

4. Morgan PB, Woods CA, Tranoudis IG, et al. International Contact Lens Prescribing in 2014. Contact Lens Spectrum. 2015 Jan;30:28-33.

5. Scheuer CA, Fridman KM, Barniak VL, et al. Retention of conditioning agent hyaluronan on hydrogel contact lenses. Cont Lens Anterior Eye. 2010 Dec;33 Suppl 1:S2-6.

6. Senchyna M, Stauff er P, Davis J, et al. Char-acterization of a multi-purpose lens solution designed for silicone hydrogel materials. IOVS. 2010 Apr;51(13):3426.

7. Napier L, Garofalo R, Lemp J, et al. Clinical evaluation of an investigational multi-purpose disinfecting solution. Poster presented at: Contact Lens Association of Ophthalmologists meeting, Sept. 2010, Las Vegas.

8. González-Méijome JM, da Silva AC, Faria-Ri-beiro M, et al. Multi-site clinical assessment of Complete Revitalens MPDS in 2981 contact lens wearers across Europe and USA. Cont Lens Ante-rior Eye. 2013 Dec;36(6):289-93.

9. Millard KA, Hook D, Hoteling A, Wygladacz K. A one-step hydrogen peroxide-based contact lens solution. Contact Lens Spectrum. Special Edition 2014.

10. Contact Lens Research Services. Andrasko Corneal Staining Grid. Available at: www.staining-grid.com. Accessed November 20, 2015.

FIg. 1. Patients with giant papillary conjunctivitis may benefi t from switching to a

peroxide system.

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By J. James Thimons, OD

Corneal Consult


Treating with antibacterial drugs can be tempting when presented with acute infection, but fi rst make sure the agent matches the organism.

The Case of the Finicky Fungus

A 68-year-old Caucasian female contact lens wearer presented for an emergency evalua-

tion on a Sunday evening with a complaint of severe pain in one eye. Her history was signifi cant for an eight-day treatment of that eye with topical Vigamox (moxifl oxa-cin, Alcon) QID and an unspecifi ed steroid drop BID. According to the patient, she initially responded well to the aforementioned treatment, but had since developed a case of intense ocular pain and mild vision loss over the past 24 to 48 hours.

A physical examination revealed the right eye to have normal visual acuity at 20/20- with correction. The left eye with correction was 20/50, pinholing to 20/25-. An ex-ternal exam revealed a notable area of conjunctival infl ammation and hyperemia located in the inferior nasal sector. The remainder of the conjunctiva was relatively clear. An anterior chamber reaction was present, but less than 1+, and the globe demonstrated a remarkable tenderness to touch when palpated through the lid, with the patient indicating pain when the lid was retracted for slit lamp assessment. The cornea displayed a well-defi ned 2.5mm epithelial defect with no associated infi ltration or thinning of the tissue. No purulent activity was detected, and defect margins were soft, but well defi ned.

A dilated examination using tropicamide and homatropine showed no evidence of vitreous cells, and the homatropine provided relief of the pain.

The patient was advised of possible etiologies and alternate treatment options, as the lesion had shown no improvement after a week of therapy. Scrapings from the patient were cultured on chocolate, blood, thioglycolate and Sabouraud’s media and plated on slides. These were delivered to the laboratory for assessment of cellular constitution, as well as resistance and sensitivity. Because of the eight days of prior treatment, expecta-tions for growth were relatively limited; however, I asked that the plates be kept by the laboratory for further evaluation of atypical organisms—specifi cally, Nocardia, atypical Mycobacterium and other fungi that require an extended growth opportunity to demonstrate their presence.

With regards to the current presentation, potential factors of note included an insuffi cient dosing regimen, given that current therapy was being administered QID with no signifi cant effect. The possibili-ty that the organism was resistant to Vigamox was also considered; thus, the question was whether to maintain the current agent, add an additional therapeutic item and change the dosage, or switch to a more aggressive therapeutic regi-men. Given the late hour of the day and the limited pharmacy options available at that time, I elected to increase the Vigamox to Q2h and add Neosporin ointment TID to the affected eye to increase gram-posi-tive bacterial coverage until fortifi ed agents became available if needed. I also elected to discontinue the steroid that was being administered

BID, given the lack of positive response, and add homatropine 5% TID in light of its effect on pain.

THE TWIST

Two days after the aforementioned change in therapy, no notable improvement in the course or symptoms was observed, though the margins of the lesion appeared slightly softer than previously noted. A trace infi ltrate was also apparent below the epithelial defect with no thinning observed. Additionally, the anterior chamber showed trace cell. In light of the relative status quo of the presentation, I elected to contin-ue the recently instituted therapeutic course, but watch the patient care-fully. The patient was scheduled for another follow-up exam two days hence, but contacted the offi ce late the following day to advise that the eye had become markedly worse in the last 12 hours, with an increase in redness and discomfort, and a decrease in vision clarity.

Clinical assessment that evening revealed a lesion with minimal increase in the stromal infi ltration in the anterior stromal bed immediate-ly below the lesion. The margin of the lesion appeared improved and well-circumscribed, and the tissue was not soft or pliable as before; however, the anterior chamber showed an increase to 1-2+ re-action, with no hypopyon. No signifi cant stromal haze was present outside the area of defect. The globe itself was 3-4+ hyperemic, with an intense zone of ciliary fl ush.

At that point, I advised the pa-tient that because of the duration of treatment without visible success, I

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was becoming concerned that this was not a typical bacterial infec-tion, and that the lack of resolution warranted a change in therapeutic intention. I placed the patient on vancomycin Q1hr alternating with Vigamox Q1hr, and discontinued the Neosporin. The patient was atropinized in the offi ce, and then subsequently scripted for atropine on a once-daily basis, given the sig-nifi cant decrease in her discomfort level as a result of the relaxation of the ciliary spasm.

The laboratory was contacted that evening for culture evalua-tion; no growth was reported. The patient was seen 36 hours after initiation of the additional vanco-mycin therapy and reported that the eye felt mildly improved. Clinical assessment showed no change in the lesion, although there was a notable decrease in the infl ammato-ry response of the anterior chamber secondary to the use of the atropine.

In the case of lesions of this duration without notable response, the possibility of a viral or oth-er non-bacterial etiology must be considered, though given the appearance of this lesion and the lack of relative neurotrophia on examination, this was unlikely. That being said, the patient was placed on 500mg valcyclovir TID PO and asked to return in two days. At subsequent visits over the following week, the patient showed no nota-ble change. The vancomycin and Vigamox were reduced to QID as a result of the lack of response, and the patient was maintained on oral antiviral therapy. The atropine was decreased to once every other day.

A NEW

HOPE

At this point, discussions with respect to the lack of effi cacy of any of the interven-tions, as well as the lack of progression of the lesion and the absence of a positive laboratory outcome from the cultures, led to the deci-sion for a second opinion.

Due to the lack of response to a traditional therapeutic regimen, even though the lesion was without satellite involvement and minimal to any infi ltrative change or necro-sis, the next step was to institute a topical antifungal agent.

The patient was placed on Q2h natamycin therapy with mainte-nance of topical Vigamox QID and the oral antiviral, and discontinu-ation of the vancomycin. The lab-oratory again reported no growth; ironically, however, the patient showed improvement in the fi rst 24 hours on the natamycin. By the third day, the lesion had improved dramatically. It was at this time that laboratory results indicated a Fusarium infection.

The natamycin was maintained with an antibiotic to provide pro-phylaxis against infection from an opportunistic agent while the eye was compromised by the fungus. The patient’s acuity ultimately

returned to almost 20/20 without correction. The anterior chamber was quiet at the last visit, and the lesion was completely resolved.

One interesting aspect of this case: this patient was an

avid gardener and, despite the late phase of the season in the north, fungus is not typical; however, the decision to discontinue the steroid and obtain a true picture of the disease state was the key point. In this case, the net change in status was mild, unlike other fungal cases I have managed where discontinu-ation resulted in rapid progression of the disease state. Having treated one of the fi rst patients in the United States during the Fusariumoutbreak several years ago, I requested that the patient bring her contact lenses, lens case and solution to the offi ce to forward to the laboratory for assessment. As of four weeks later, no growth had been identifi ed. RCCL

A minimal ulcer and slight stromal involvement

characterized this patient’s presentation.

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Familiarizing yourself with corneal mapping can lead to more success with your GP contact lens patients.

By Vivian Phan Shibayama, OD

Although the manual keratometer has served eye doctors well for over 150 years, the advent of corneal topography

has revolutionized our ability to discern corneal shape characteristics, as topographers have largely replaced the keratometer as the essential component in the contact lens fi tting process. Allowing practitioners to see beyond the 3mm limit of the keratometer, a corneal topographer also gives us the ability to analyze the cornea in three dimensions when assessing shape characteristics.

Especially now that the tech-nology is equipped to provide more information about the cornea than just the central curvature readings, we must consider how best to use these maps to benefi t our contact lens practice. For example, proper analysis of the map can help us select a more accurate initial lens, determine lens type and assist in making the proper adjustments to the lens fi t.

This article will cover the different types of corneal topography maps and how to use this information to fi t corneal rigid gas permeable (GP) and scleral lenses.

TYPES OF TOPOGRAPHY

There are two methods of record-ing corneal topography: refl ec-tion-based and projection-based. Refl ection-based topography—the most widely used—is further divided into raster photogram-metry and placido-based topog-raphy. Raster photogrammetry reads curvature by taking multiple triangulated measurements using a projector and two cameras. Currently, this relatively new tech-nology is being used to measure scleral curvature for scleral lens fi tting. Placido-based topogra-phers, in contrast, use multiple concentric rings refl ected off the corneal surface to analyze corneal curvature using slope; the height of the cornea is extrapolated from these measurements. This method is dependent on the quality of the refl ection, so images are sometimes

FITTING RIGID LENSES USINGCORNEAL TOPOGRAPHY

Dr. Shibayama recently

completed a one-year

specialty contact lens

fellowship at the Jules Stein

Eye Institute following

graduation from the

Pennsylvania College of

Optometry, before taking

over the specialty lens practice

from her mentor, Barry Weissman, OD.

Her practice consists of 80% specialty

fi ts, including keratoconus, post-corneal

transplants, scars, dry eyes, post-refractive

ectasia and infantile aphakia.

ABOUT THE AUTHOR

Familiarizing

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diffi cult to capture if the cornea is badly distorted, as in the case of advanced ocular surface disease (Figure 1).1

Projection- or elevation-based topography measures the anterior and posterior corneal surface by both refl ection and light pro-jection through the cornea. The Orbscan (Technolas) uses optical slit-scan imaging and the Pentacam (Oculus) uses rotating Scheimpfl ug imaging to acquire data (Figure 2). Projection-based topography mea-sures height and specifi c points on the cornea. From height, the slope and radius of curvature is mea-sured, making these measurements more precise than refl ection-based topography. In addition, projec-tion-based topography does not rely on the quality of the refl ection from the cornea and can read bad-ly distorted corneal surfaces.1

TYPES OF

TOPOGRAPHY

MAPS

• Axial Map. This displays the rate of local curvature change of the anterior surface, based on the placido image. Curvature measurements are made between the placido rings. Light is assumed to be refracted from the corneal surface, using the optical center as the reference points; as such, the map is more

sensitive to changes in central curvature versus in the periphery.2

Axial maps are particularly useful for determining the meridian, regu-larity and amount of astigmatism.

• Elevation Map. The most valuable map for corneal GP fi tting, the elevation map appears most similar to the contact lens fl uorescein pattern. In this display,

different elevations on the cornea are measured from an average reference point. Areas higher than the reference will appear red and yellow, while the lower areas will appear green or blue. It is import-ant to combine data from both the axial map and elevation map while fi tting contact lenses.

While the axial map will demon-strate the curvature of the eye, the elevation map will provide more detailed information with regards to the unique shape of the cornea—the steepest point of the cornea is not necessarily the most elevated.

• Tangential or Instantaneous Map. This is the most sensitive map for determining changes in curvature in the peripheral region of the cornea. These maps include peripheral curvature in the calcu-lations for scaled curvature and don’t use a central reference point.2

It is particularly useful when fi tting corneas that have curvature chang-es in the periphery, as in post-re-fractive surgery patients (Figure 3).2 Tangential maps can also help determine the exact shape and size of the cone in keratoconus.3

Fig. 2. Scheimpfl ug image from Pentacam.

Fig. 3. Comparison of axial and tangential maps on a post-refractive patient.

Readings of center curvature are the same, but vary greatly in the periphery.

Fig. 1. Poor image capture from a patient with ocular

surface disease.



PROJECTION-BASED MAPS

• Anterior Float. After calculat-ing a best-fi t sphere for the ante-rior corneal surface, the anterior fl oat demonstrates elevation above and below this hypothetical plane, with warm colors present above the sphere and cool colors present below it. This map is useful in assessing the regularity of astigma-tism and areas of asymmetry, and is similar to the axial map.3

• Posterior Float. A display of the elevation above and below a best-fi t sphere for the posterior cor-nea surface is used here similarly as in the anterior fl oat. Acquiring a map of the posterior surface has become the gold standard in ruling out the presence of forme fruste keratoconus in patients during LASIK consultations.3 Changes in the patient’s epithelial basement membrane and Bowman’s layer are the fi rst histological changes in keratoconus.4 Traditionally, only the anterior surface of the cornea is evaluated when fi tting a contact lens; as such, any irregularity of

the posterior cor-nea is assumed to remain uncorrect-ed by placement of a contact lens on the anterior surface, thus affecting the pa-tient’s fi nal visual acuity (Figure 4). Posterior eleva-tion topographic maps may be able to provide practi-tioners with better target visual acuity for con-tact lens fi tting. Within the visual axis, for patients with a posterior elevation between 70µm and 100µm,

a practitioner should expect no better than 20/30 acuity; between 130µm and 140µm, no better than 20/40 acuity; and greater than >200µm, no better than 20/70 acuity.

GP FITTING

The primary goal of GP fi tting is to respect the shape of the cornea as much as possible without infl icting damage or changes on the ocular surface. In the case of a normal cornea, it is not always necessary to use corneal topography to design lenses; however, periph-eral corneal data can be valuable in determining what type of lens to choose for your patients. This data is espe-cially important if the practi-tioner decides to fi t a larger diameter.

Corneas with a higher rate of fl attening may benefi t from aspher-ic designs. The term eccentricity value (E value) describes the rate of fl attening in the cornea (Figure 5). Normal corneas exhibit an E value of approximately 0.55.5 Higher than average E values indi-cate a prolate cornea that fl attens at a more rapid rate, such as in keratoconus.

Corneal alignment of the GP lens in the midperiphery can be managed by increasing or decreas-ing the E value of the GP accord-ing to the E value on the topogra-phy.6 In normal corneas, contact lenses with normal eccentricity values can decenter on patients with higher than average E values. In an irregular cornea, such as in a keratoconus patient, the mid-periphery is usually signifi cantly fl atter than the apex. Increasing the E value in both cases will assist in the alignment of the lens with-out sacrifi cing the alignment of the central fi t.6

When fi tting a toric cornea, an axial topography map can be used to visualize the nature of the astigmatism (i.e., how regular or irregular it is and how far it extends throughout the cornea). This information can help the practitioner make decisions about diameter and the peripheral fi t of the lens.

Fig. 4. A keratoconus patient showing a posterior

elevation of 104μm and GP corrected BVA of 20/30.

Notice the focal elevation of the central cone on the

elevation map vs. the broad area of steepening on

the axial map. The tangential map will show the most

accurate size and curvature of the cone.

Fig. 5. Indices: eccentricity, pupil diameter, horizontal

visible iris diameter.

FITTING RIGID LENSES USING CORNEAL TOPOGRAPHY



In multifocal lens fi tting, new theories in multifocal design have emphasized the importance of the centration of multifocal optics in order for the fi t to be successful. The topographer can be used to obtain an objective measure-ment of pupillary size to assist in optic zone design (Figure 5). Topography can also be used to check multifocal optics alignment through the patient’s line of sight while the patient is wearing the lens (Figure 6).7

Some topographers come equipped with software programs that can assist virtually with con-tact lens fi tting. Brand name lenses as well as generic lens parameters are preloaded into these programs for the practitioner to choose from. These programs allow the practitioner to select a lens and will simulate the fl uorescein pat-tern of the lens using the patient’s corneal map. The practitioner can then adjust the lens parameters and see the changes in the fl uores-cein pattern.8

KERATOCONUS

In keratoconus, the key to lens selection is to determine the size, shape and location of the cone. To do this, again, compare the axial, tangential and elevation maps. The axial map will show the overall shape and curvature of the eye,

while the elevation map will show the shape of the cone.

Tangential maps can help the practitioner measure the size and shape of the cone, which can be helpful in determining overall diameter as well as optic zone size (Figure 4). Tangential maps may also provide more accurate curvature information about the periphery of the cornea to aid the practitioner in designing peripheral curves for the patient.

Small diameter lenses are best for the nipple form of keratoco-nus—in which the cone is located centrally, steeply curved and typ-ically less than 5mm in diame-ter—while large diameter lenses are preferable for decentered cones, which are displaced from the apical center into the inferior quadrant. Large diameter lenses are also best for oval cones, which typically measure more than 5mm in diameter and are characterized by a broad area of elevation in the

inferior cornea, as they provide forced centration over the pupil. Reverse geometry lenses can also be helpful for centration with a secondary curve steeper than the central base curve to accommodate the decentered cone without exces-sive central vault.

Pellucid marginal degeneration (PMD) is typically characterized by the presence of a “kissing doves” pattern on the axial map (Figure 7), which represents the thinning that occurs 1mm to 2mm away from the limbus. Once a diagnosis of PMD is confi rmed, the elevation map should be referenced to fi nd the location and elevation of the cone.

Traditional keratoconic lenses do not fi t patients with PMD; instead, these patients should be fi t with large diameter reverse geometry lenses or scleral lenses to accom-modate the steepness in the mid periphery.1 Once the diameter and lens design is determined, the next step is to select the base curve. There are many opinions on the best way to choose the initial lens for your patient, from selecting the

Fig. 6. Topography over multifocal GP showing line of sight centered on the

right (fi t on K) and decentered up on the left (fi t fl at).

Fig. 8. Comparison of theoretical Medmont software

fl uorescein pattern compared to real diagnostic lens.

Fig. 7. A patient with PMD. The tangential map shows

steepening inferior to what is displayed in the axial map.

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lens based on the yellow curva-ture on the axial map to fi tting 0.2 fl atter to average K reading and selecting the reference sphere from the elevation map. The best suggestion is to follow the method of the fi tting guide of the lens that is being used.1

POST-GRAFT FITTING

There are many factors to consider when choosing the right type of lens for a patient who has under-gone corneal grafting. The physi-ologic needs of the donor cornea must be respected, reducing me-chanical and hypoxic stress to the cornea and the risk of neovascu-larization and rejection. Generally, contact lenses don’t cause graft rejection; however complications from contact lens wear can.10,11

Gas permeable lenses in general of-fer the best visual correction, and corneal GPs specifi cally have the best oxygen transmission. Corneal GPs should be considered fi rst

with fi tting post graft patients.10 Approximately 20% of patients who undergo PKP still have irreg-ular astigmatism and benefi t from GP correction.12

When selecting an initial diag-nostic lens, compare the axial and elevation maps to determine the shape of the graft. Larger diameter GP lenses (i.e., 10.5mm to 12mm) are best suited to cover the graft/host junction of most grafts, while keratoconic designs fi t optimally over prolate grafts (31% of grafts), which are steeper in the center and fl atter in the periphery. Oblate or plateau-shaped corneas (31% of grafts) typically benefi t best in a reverse geometry design that is fl atter in the center with a steeper secondary curve (Figure 9). In the case of a mixed prolate/oblate cor-nea with symmetrical astigmatism (18% of grafts), use the axial map to determine how regular the astig-matism is and how far it extends throughout the graft.

Bitoric or back surface toric designs are best suited for corneas with symmetrical astigmatism, as they distribute the weight of the lens as evenly as possible (Figure 10). This lens can be fi t much like a traditional bitoric, using the axial map curvature readings to align the fl at base curve to the fl at meridian. Add only two-thirds of the total toricity to the steep meridian—it is safer to add less toricity than is believed necessary to encourage lens rock and tear exchange.13 A bitoric lens that is too tight can result in mechanical trauma to the graft.

Grafts with asymmetrical astig-matism account for 9% of grafts. These corneas are most successful in large diameter spherical lenses, which mask the irregular astigma-tism. Thirteen percent of grafts are tilted (i.e., transitioning from steep to fl at). Tilted grafts are consid-ered by many practitioners to be the most diffi cult to fi t, and often require a large diameter GP lens or scleral lens.12

SCLERAL LENSES

Similar to keratoconic lens de-signs, each scleral lens fi tting set will recommend its own method of choosing an initial diagnostic Fig. 10. Graft with regular astigmatism.

Fig. 9. Oblate graft.

FITTING RIGID LENSES USING CORNEAL TOPOGRAPHY

Fig. 11. Image from sMap3D from

Visionary Optics.

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lens. Practitioners may be directed either to begin by selecting the middle lens in the set or using the patient’s sagittal height, hori-zontal visible iris diameter or a trial-and-error method to fi nd the right lens. Since these lenses are fi t predominantly based on sagittal height, keratometric readings don’t typically provide enough informa-tion to tell us which lens would fi t the patient best; instead, these readings give information on the pathology and general shape of the cornea to help us determine if we need to fi t the lens fl at (for post-re-fractive cornea) or steep (for ker-atoconus). However, topography systems do offer more information about other aspects of the corneal surface that can help practitioners make a decision. This includes:

• Elevation Map. This indicates the most elevated area of the cornea, which is crucial to know when selecting a lens to fi t. If the elevation is decentered, a reverse

geometry scleral lens allows for vault in the midperiphery without too much central clearance.

• HVID. Horizontal visible iris diameter is an important measure-ment because it is necessary for the scleral lens to clear the limbus and land outside the corneal/scleral junction. Knowing the HVID mea-surement of the patient’s eye will help you select the right diameter for your patient.14

• Sagittal Height. The most accurate method of selecting an initial scleral lens, sagittal height is the measurement from the center of the cornea to the intersection of a specifi c chord length. Most topographers give the sagittal depth of the patient’s cornea to a chord length of 10mm. If fi tting a 15mm lens, 2,000µm—the average sagittal height for most eye types from a chord length of 10mm to 15mm—will need to be added.12

Another 350µm should also be included to account for necessary corneal clearance. Sagittal height will also need to increase when in-creasing the lens diameter; roughly 300µm per millimeter of lens diam-eter change is considered ideal.14

• Fitting the Periphery. New technology from a few different companies has given us the ability to map the scleral contour, mak-ing it easier to fi t patients with toric scleras. Visionary Optics has a unique design that maps scler-al curvature to better align the peripheral fi t of its Europa lenses. The sMap3D system (Precision Ocular Metrology) incorporates raster photogrammetry, which takes multiple, triangulated measurements using a projector and two cameras to determine corneal and scleral measurements. Fluorescence is used to image the bulbar conjunctiva. Images are taken while the patient is look-ing straight ahead, up and down;

these three images are then pieced together to create a three-dimen-sional model of the eye, sent to the laboratory and used to assist in the manufacturing of the lens.14

In conclusion, a proper assess-ment and comparison of the

various topographical maps will enable practitioners to stream-line contact lens fi tting. Some say contact lens fi tting is more of an art form than a science. With that said, I don’t believe technology will ever fully replace the judgment of a skilled practitioner; however, if used properly, topographers can assist in reducing chair time, increasing patient success and keeping costs down. RCCL

1. Gas Permeable Lens Institute. GP Lecture Series. Available at: www.gpli.info/gp-lecture-se-ries/. Accessed November 10, 2015.2. Szczotka-Flynn L, Jani BR. Comparison of axial and tangential topographic algorithms for contact lens fi tting after LASIK. Eye Contact Lens. 2005 Nov;31(6):257-62.3. Sutphin J, Dana R, Florakis G, et al. Basic and Clinical Science Course, Section 08: External Disease and Cornea. San Francisco: American Academy of Ophthalmology. 2006-2007:39-48.4. Barbara A. Textbook on Keratoconus: New Insights. New Delhi: Jaypee Highlights Medical Publishers. 2012:50-51.5. Hansen D. Evaluating the eye with corneal topography. Contact Lens Spectrum. August 2003.6. Indovina K, Potter R. Eccentricity changes in GP lens design. Contact Lens Spectrum. April 2008.7. Brujic M, Miller J. Repurposing the offi ce to-pographer. Review of Cornea and Contact Lens. June 2012.8. Eiden B, DeNayer G, Brafman S, et al. Using advanced technologies for contact lens fi tting. Contact Lens Spectrum. August 2012.9. Sindt C. Evaluating virtual fi tting for keratoco-nus. Contact Lens Spectrum. May 2011.10. Kaufman H, Barron B, McDonald M. The Cor-nea, 2nd Ed. Butterworth-Heinemann 1998.11. Geerards AJ, Vreugdenhil W. Khazen A. Inci-dence of rigid gas-permeable contact lens wear after keratoplasty for keratoconus. Eye Contact Lens. 2006 Jul;32(4):207-10.12.Hom M, Bruce A. Contact Lens Prescribing and Fitting. 3rd ed. Philadelphia: Butterworth, Heinemann, Elsevier. 2006.13. Phan VA, Kim YH, Yang C, Weissman BA. Bitoric rigid gas permeable contact lenses in the optical management of penetrating keratoplasty. Contact Lens Anterior Eye. 2014 Feb;37(1):16-9.14. Jedlicka J, Denaeyer G. Critical measurements to improve scleral lens fi tting. Review of Cornea and Contact Lenses. September 2015.

Fig. 12. Steep, prolate graft.



By Jane Cole,Contributing Editor

Talk to any contact lens practitioner about the patient habits that bother them most and “failure to replace lens-

es on time” will always be near the top of the list. Patients have been known to come in wearing lenses that are months or even years past their expected replace-ment date. Despite all the edu-cation about health benefi ts and greater comfort from frequent or daily replacement, a fair amount of patients just don’t feel com-pelled to change something they perceive to be working just fi ne.

Are practitioners sometimes guilty of the same inertia? Many rely on a few go-to modalities—tried and true lenses they have turned to for years because they believe in the idea, “If it’s not broke, don’t fi x it?” If patients wearing older lenses remain truly happy and healthy, odds are they can continue without incident. But if such habits keep practitioners from exploring newer designs that might lead to more success with existing or new lens wearers, experts say it’s time to break from this routine; it could be holding the practice back.

“We often don’t even realize the habits we develop in clinical practice,” says Mile Brujic, OD, of Premier Vision Group in Ohio. “Certain procedures and protocols

become so routine that we don’t even think about them. This is most often true in our contact lens practices.”

Many of today’s new lens de-signs provide patients with more comfort and clarity, and fewer limitations, than ever before. But doctors who feel their current product mix is good enough will miss out.

Practice management consul-tant Gary Gerber, OD, of New Jersey adds that incorporating new lens options demonstrates a message of progress. “Just like many patients are wired and plugged in [with the latest technology] to some extent, they also expect their consumer and health care experiences to be as up to date,” he says. “If you do not offer new products, or at least mention or broadcast that you do—even if they may not be clinically appropriate for every patient—you’re sending a message that not only are you out of date, but out of touch.”

LENSES AS

PRACTICE BUILDERS

“Recent advancements make it possible to fi t almost anyone in contact lenses, if they so choose,” says optometrist Gina Wesley of Complete Eye Care Medina in Minnesota. “Between the ex-pansion of the daily disposable

parameters in torics and multifo-cals, colored lenses, new monthly options and the wide range of prescriptive sclerals, advancements in this arena have never looked better.”

These options offer practitioners the ability to fi t a patient quick-er and more effectively, which increases the value of the service offered, she adds. “Your patient appreciates the advancements and less chair time is necessary, which is better for the practice. New designs open the door to multiple contact lens prescriptions, just like we prescribe multiple spectacle prescriptions.”

Newer lens designs also offer distinct fi nancial benefi ts to the practice, in addition to their major health benefi ts to patients, says David Kading, OD, of Specialty Eyecare Group in Seattle. Though some of the newer options have higher price tags, Dr. Kading believes optometrists should still market these lenses to patients because of their positive effect on patient well-being.

“As optometrists, we often don’t think our patients are willing to update beyond the old technology because it’s going to cost more money or because the patient may think that what they have is fi ne or good enough,” he says. “Our job is not to save our patients money or keep them in

Forward THINKING:By Jane Cole,

Contributing Editor

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From sclerals to daily disposables and tinted lenses, new designs can add to your practice if you’re willing to change your mindset.

Where Can New LensesLead Your Practice?

‘good enough’ lenses, but to give them the healthiest and most ap-propriate option for their unique needs. With that mindset, we need to educate patients on the new designs and technologies that will ultimately serve their long-term better health.”

Maintaining the belief in the individual as one’s best source of

marketing for contact lens fi ttings pays off, Dr. Wesley points out. “You know exactly what this patient would benefi t from, or is eligible to wear, and you can tailor your message to give that patient options. This, in turn, leads to word-of-mouth and referrals.” Initially, she discloses, in 2012 only 8% of her contact lens pa-

tient base wore a daily disposable lens; that num-ber is up to 75% today.

For Justin Bazan, OD, of Park Slope Eye in New York, more contact lens design options mean an achievement of better performance in both the indus-try and private practice. “We have seen advances in contact lens materials devel-op to the point where end-of-day comfort issues are minimal—if not non-existent—for many patients,” he says. And newer designs benefi t wearers “because they provide the

patient with the performance they demand and need,” he says. “They help benefi t the practice by generating strong word of mouth and help build the practice’s posi-tive reputation in the community.”

SPECIAL DELIVERY

When Stephanie Woo, OD, joined her practice in Arizona, this board member of the Scleral Lens Education Society knew she faced a major challenge. The 25-year-old practice focused on primary care and ocular disease manage-ment, not on specialty lenses as she had hoped. However, Dr. Woo wasn’t deterred.

“I knew there had to be plenty of potential specialty contact lens patients out there that just didn’t know what options they had,” she says. “I was committed to recom-mending specialty contact lenses to any patient who was a good candidate.” Most of her current specialty lens wearers began as ‘regular’ patients sitting in her chair for their annual eye or con-tact lens exam. Today, Dr. Woo estimates she sees three to four returning specialty lens patients on a daily basis and performs three to fi ve new fi ts per week. These include gas permeable (GP), bi-toric, GP multifocals, scleral lenses for regular and irregular corneas, scleral multifocals, soft custom lenses, prosthetic soft lenses,

Dr. Woo prepares to take a mold of a patient’s sclera

with the EyePrintPro scleral lens design system.

Photo: Stephanie Woo, O

D

From sclerals to daily disposables and tinted lenses, new despractice if you’re willing to change your mindset.



orthokeratology, myopia control, hybrid lenses, hybrid multifocals and EyePrint ocular prosthetic lenses.

By offering specialty lenses, Dr. Woo gives options to patients who thought they would never see that clearly again. This is both truly rewarding in the personal sense and also a benefi t to her practice, she says.

“Specialty contact lens patients are extremely loyal to the practice, and offering this unique service helps our business grow,” Dr. Woo explains. “Specialty lens patients are some of the happiest patients, and they are quick to refer all of their friends and family to the clinic. It gives us the opportunity to help many people.”

For other optometrists looking to add specialty lenses to their practices, her marketing advice is simple: explain to the patient during the exam why they would be a good candidate. Dr. Woo also suggests directing the patient to try a new contact lens, letting them know it may improve their vision and also reassuring them that if the lens doesn’t improve vi-sion or if the fi t is uncomfortable, they can always return to wearing their old contacts or glasses.

“This statement puts patients at ease, knowing they are not inadvertently committing to these lenses if things don’t work out. Most of my patients are willing to at least try a specialty lens if they understand why they need it.”

Dr. Kading points out that sclerals are one of the hottest areas of growth in the contact lens industry. “I think custom lenses are one of the biggest innovations in the past few years, and they are also providing a dramatic impact on patients’ lives,” he explains. While it’s true that scleral lenses can generate substantial revenue

for the practice, he says, “more importantly, the patients who need them are often on disability, unable to work, can’t see well or comfortably go about their day. And, we’re able to quickly improve their life. What could be better than that?”

DAY-TO-DAY BENEFITS

Daily disposable contact lens op-tions are another distinct piece of the market, one that has benefi ted from materials advances in recent years that improve comfort with-out compromising quality. One of the best ways to introduce the possibility of daily disposable con-tact lenses to patients is to simply ask how comfortable they are in their current lenses. When doing so, avoid simple yes/no questions. You want to engage the patient in conversation.

“A number of patients who come into our contact lens practic-es are less comfortable in their lenses than we think they are,” explains Dr. Brujic. He adds that while a patient may say they are happy and comfortable in their current lens, they may actually be very close to petering out of contact lens wear. As a method of dropout detection, Dr. Brujic routinely asks his patients to rate their comfort level 10 minutes af-ter they place lenses on their eyes in the morning on a scale of one to 10. Then, he asks his patients to grade their comfort fi ve to 10 minutes prior to removing the lenses in the evening.

“We have found, in these seem-ingly happy contact lens wearers, that there is a precipitous drop.” He’ll then investigate closely at the slit lamp for clinical factors af-fecting the ocular surface. “But, it also gives me a great opportunity to talk about new technologies,” he says.

Dr. Kading estimates the newer generation of daily disposables represents 93% of his contact lens wearer population. In addition to greater comfort, Dr. Kading be-lieves dailies are the healthiest and most innovative of the soft lens options for his patients. Patients who are recommended dailies tend to purchase their lenses at regu-lar intervals. “Being compliant is obviously better for the patient’s health,” he says. Typically, a sale of daily disposable lenses pays the practice double what a monthly disposable lens would pay. To off-set the higher cost of the lenses for the patient, he typically informs them they will save between $200 and $400 annually by not having to purchase contact lens solution.

“That profi tability is obviously much appreciated,” Dr. Kading acknowledges, “but again, fi rst and foremost, we want to do

Photo: Jason Miller, O

D

Encouraging contact lens patients

to share their experience on social

media is another way to market your

practice. It builds word of mouth

about what makes your care unique.

FORWARD THINKING: WHERE CAN NEW LENSES LEAD YOUR PRACTICE?


what is in the best interest of the patient.”

TARGETING PRESBYOPESMany of today’s presbyopes want to lose their glasses—and new multifocal contact lens designs provide attractive options for patients as well as another avenue to expand a practice. This is an often-cited area of practice where old habits and misperceptions do a disservice to patients and prac-tices alike. Multifocal lenses, while still requiring patient adaptation and realistic expectations, have evolved rapidly in recent years.

Dr. Kading believes that the use of practice management software can help identify patients that are suited for newer presbyopia lens designs, giving practitioners the opportunity to target them through direct mail, social media

and e-mail. He says that from a marketing standpoint, it’s best to specifi cally target the appropriate patient base for multifocal lenses, so practitioners can avoid coming across in an inappropriate manner to those who are not good candi-dates. Additionally, it saves time. “It’s like sending out a Lipitor commercial to the mass public,” he explains. “It’s defi nitely going to benefi t some people, but for others, it’s going to be a waste of time and money. We want to make sure our marketing is very pointed.”

For those who’ve previously worn or at least tried multifocals, eliciting the source of their dissat-isfaction can help you tailor the new message. What one patient struggled with—e.g., reduced comfort, poor intermediate vision, astigmatism—another might not

even notice. This is a good oppor-tunity to explain that today’s op-tions are likely better than when they fi rst tried and failed.

The opportunity to expand your contact lens practice

and increase your bottom line has never been greater. For those still clinging on to their usual contact lens staples, your colleagues sug-gest it’s high time for a change.

“My challenge for you is to think about why you are selecting the lenses that you are and remem-ber that there is a large armamen-tarium of lenses to select from that may better benefi t your patient,” Dr. Brujic says. “Do this and you will reinvigorate your contact lens practice, not only in enhancing your perspective on lens selection but also by providing your pa-tients the best lens possible.” RCCL

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Dr. Christensen is currently

director of clinical research

and an attending doctor

in the cornea and contact

lens and adult primary

care services at Southern

College of Optometry.

Dr. Larson attended and

completed a residency

at Pennsylvania College

of Optometry at Salus

University following work

as high school teacher for

two years. After three years

in private practice in northern

Virginia, she joined the faculty

at the University of Iowa as a contact lens

and dry eye specialist.

ABOUT THE AUTHORS


ABABABOUOUOUTTT THTHTHEEEE AUAUAUAUTHTHTHORORORSSSS

M anaging patients with dry eye symptoms remains a well-known challenge despite the wide array

of topical, mechanical and oral therapies available today. To put it another way, there would be no need for palliative artifi cial tears if we could truly conquer the under-

lying processes that lead to dry eye symptoms. Although treatment op-tions abound, they are fraught with compromises and shortcomings.

Technological advances like LipiFlow (TearScience), BlephEx (Scope Ophthalmics) and intense pulsed light (IPL) devices have been used to treat meibomian gland dysfunction (MGD)—the most common form of dry eye—and Demodex; however, equipment costs and space requirements often limit widespread use in practice.1

Practitioners can also prescribe less expensive options like hot compresses and lid soaks to loosen debris and instigate meibum fl ow, but some critics say heat from these treatments does not penetrate deep

Artifi cial Tears:Artifi cial Tears:Looking Beneath the SurfaceLooking Beneath the Surface

Demulcents Concentration Range

Function

• Carboxymethylcellulose sodium

0.2% to 2.5% • Increases viscosity (thickener) and stabilizes emulsions.

• Dextran 70 0.1% (when used with another demulcent)

• Increases mechanical strength of tear fi lm.

• Requires thickener due to low viscosity of compound.

• Gelatin 0.01% • Gelling agent that is seldom included.

• Glycerin 0.2% to 1% • Lubricant and humectant. • Blunts the damaging eff ects of high

osmolarity on the ocular surface. • Promotes epithelial cell growth.

• Hydroxyethyl cellulose • Hydroxypropyl-methyl-

cellulose • Methylcellulose

0.2% to 2.5% • Crosslinks upon contact with tear fi lm due to pH diff erence to increase viscosity.

• Too viscous to instill easily alone.

• Polyethylene glycol 300• Polyethylene glycol 400

0.2% to 1% • Increases viscosity and forms protective layer over mucous membrane to relieve irritation.

• Polysorbate 80 0.2% to 1% • Stabilizes oil emulsions.

• Polyvinyl alcohol 0.1% to 4% • Lowers tear viscosity.

• Povidone 0.1% to 2% • Lubricates and soothes. • Lipid that integrates with existing

oil layer, thickening it and reducing evaporation.

• Propylene glycol 0.2% to 1% • Forms a protective layer over mucous membranes, relieving infl ammation.

• Increases viscosity.• Holds up to three times its own

weight in water.

Table 1. Approved Active Demulcents

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enough or last long enough to have a positive effect on MGD.

Other therapies like lid disinfec-tants (e.g., Cliradex and Avenova) or lid scrubs (e.g., Ocusoft, TheraTears and Systane) have also been used to treat blepharitis; these have shown a clinical benefi t when used regularly.2 Long-term effects with respect to more chronic cases remain unknown, however. Other research has suggested omega-3 and omega-6 fatty acids taken orally may have a positive but limited effect on meibomian gland infl am-mation and oil quality. Autologous serum and amniotic membranes (e.g., Prokera, AmbioDisc and BioDOptix) may be used to en-hance epithelial repair, but remain expensive and hard to procure.

In light of these controversial options, many practitioners would agree the fi rst-line treatment for dry eye remains over-the-counter (OTC) artifi cial tears. OTC tears are simple enough to use, with a variety of well-known indications, including dryness, irritation and discomfort relief. However, despite their simple indications, these drops are complex formulations with a host of active and inactive ingredi-ents that can be diffi cult to evaluate. Why is this?

FDA FOLLIES

Last year, Dr. Christensen received a call from a friend looking for information on studies used for ap-proval of OTC tears, as he had been having diffi culty locating any. What he didn’t realize was that none currently exist. Though numerous well-controlled industry-sponsored, randomized clinical studies that support product package claims are available, no FDA trials for drop effi cacy have been instituted.

Why are some ingredients labeled as active and others inactive, and

why do the companies seemingly only expound on what is special about the inactive ingredients? What differentiates one company’s product from that of a competitor with the same active ingredients?

In 1988, the FDA fi nalized a monograph to help expedite arti-fi cial tears, coded “lubricant eye drops,” to the market.2 Its primary purpose was to reduce the costs and barriers associated with new product development, thus easing manufacturing and marketing efforts. Under the new document,

These seemingly simple drops are more complex than you think. Do you know what’s in them?yy theem?

By Mike Christensen, OD, PhD,

and Tressa Larson, OD

Emollients Concentration Range

Function

• Anhydrous lanolin • Lanolin

1% to 10% in combination with one or more listed oleaginous emollient.

• Lubricates and soothes..• Contributes to oil layer.

• Light mineral oil • Mineral oil

Up to 50% in combination with one or more listed emollient.

• Replaces or thickens lipid layer to increase tear stability and TBUT.

• Seals in existing moisture, but is non-moisturizing.

• Paraffi n Up to 5% in combination with one or more listed emollient.

• Seals in moisture.• Waxy consistency.

• Petrolatum • White ointment • White petrolatum

Up to 100%. • Lubricant that contributes to oil layer.

• White wax • Yellow wax

Up to 5% in combination with one or more listed emollient.

• Contributes to oil layer.

Table 2. Approved Active Emollients



the company must notify the FDA of its intention to release an artifi cial tear to the public. To approve the drop, the agency evaluates its safety via toxicology testing and checks to ensure good manufacturing pro-cedures. The monograph contains specifi c details on the indications for use; namely, one of the following:

• Temporary relief of burning and irritation due to dryness of the eye.

• Temporary relief of discomfort due to minor irritation of the eye or to exposure to wind or sun.

• As a protectant against further irritation or to relieve ocular dryness.

• As a lubricant to prevent further irritation or to relieve ocular dryness.

The FDA also requires manufac-tures to include the following box statement on the box: “Stop use and ask your doctor if you experience eye pain, changes in vision, contin-ued redness or irritation of the eye, or if the aforementioned condition worsens or persists for more than 72 hours.”

The active ingredients in the monograph comprise a list of demulcents or emollients (Tables 1 and 2).3-7 A demulcent is a high molecular weight polymer substance that relieves irritation of the mucous membranes by forming a protective mucous-mimicking fi lm that acts to lubricate, protect and increase the viscosity of the eye drop. Emollients, in contrast, are oleaginous substanc-es that include fats and oils, which work to reduce evaporation. As part of the monograph’s development, the FDA deemed a specifi c range of concentrations as safe and effective for these drugs; it was also decided that extra or repetitive testing was unnecessary for future products.

In this sense, the ingredients listed in the monograph are “safe,” and overuse constitutes minimal risk to the patient. Only these ingredients can be considered for the fast track of FDA approval. Therefore, the result of the simplifi ed monograph ruling had an unforeseen conse-quence: it has resulted in a plethora of products on the shelf but no new active ingredients in nearly 30 years.

A new polymer requires a new drug application process to show that it is a pharmacologically active drug. Signifi cant improvement in a sign and symptom must be shown; additionally, results using the new formula must be demonstrated. This is an exceedingly diffi cult task and sometimes not worth the investment of time and funding, since it can be added as a non-pharmacologically active polymer under the non-active ingredients.

ARARTIFICIAL TEAEARSRS:: LOLOOKING BENEATH THE SURFACEAARTIFICIAL TEAE RSRS:: LOLOOKO INNG BENEATH THE SURFACE

Inactive Ingredients Function

• Sorbitol • Lowers the viscosity of gelling agents.• Dissipates quickly, optimizing viscosity.

• Hyaluronic acid • Binds multiples of its weight in water. • Lowers tear osmolarity. • Adheres to ocular surface. • Stabilizes and evens out the tear fi lm. • Highly viscous until blinking thins it out. • Improves cell-cell adhesion.

• Sodium hyaluronate • Protects and promotes healing of corneal epithelium. • Changes viscosity upon blinking (i.e., more viscous

while the eye is open). • Improves tear break-up time and helps spreading.• Helps control localized infl ammation.• Reduces mucous strands.• Lowers tear osmolarity.• Retains water, increasing surface wettability.

• Levocarnitine• Erythritol

• Blunts the damaging eff ects of high osmolarity by preventing stress activation.

• Absorbed by dehydrated cells to promote hydration.• Prevents cell shrinkage and infl ammation.

• Hydroxypropyl guar • Increases viscosity. • Mimics the mucin layer of the eye.• Binds to cornea and aqueous layer.• Prolongs the effi cacy of active ingredients.• Actively crosslinks/gels at pH above pH 7.

• Polyacrylic acid • Increases viscosity/retention time of tears.

• Tyloxapol • Surfactant and mucolytic agent.

• Tromethamine • Organic amine proton acceptor. • Emulsifying agent that thins waxy agents.

• Boric acid • Borate buff er • Sodium-citrate• Phosphate• Phosphate-acetate• Phosphate-citrate• Phosphate-citrate-bicarbonate• Sodium hydroxide

• Buff er systems used to obtain a pH for the artifi cial tear that is healthy and comfortable for the eye.

• A pH of 8.5 is most comfortable for dry eye patients (normal tear pH is about 7.5).

• Calcium chloride• Magnesium chloride• Potassium chloride• Zinc chloride• Sodium chloride• Sodium citrate• Sodium lactate• Sodium bicarbonate

• Electrolytes are added to maintain or lower tear osmolarity, as high osmolarity products pull water from epithelial cells, interfering with metabolism.

• Some of the added electrolytes are also important for corneal epithelial metabolism.

• Some electrolytes are part of buff er systems.

Table 3. Approved Inactive Ingredients


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REVIEW OF OPTOMETRY®EDUCATIONAL MEETINGS OF CLINICAL EXCELLENCE

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ARARTIFICIAL TEAEARSRS:: LOLOOKO INNG BENEATH THE SURFACE

DIFFERENCE MAKERS

Other than the typical ingredients in artifi cial tears like boric acid, calci-um chloride, magnesium chloride, potassium chloride, purifi ed water and preservatives, inactives like hyaluronic acid along with hydroxy-propyl guar, erythritol/levocarnitine and sodium provide the distinguish-ing factors that give each artifi cial tear its unique characteristics, improving their effi cacy (Tables 3 and 4). 3-7 For example, BlinkTears (AMO) contains polyethylene glycol 400 0.25% as an active ingredient and sodium hyaluronate as an inac-tive ingredient. Sodium hyaluronate is a humectant that binds many times its weight in water, reduces mucous strands and is better at low-ering tear osmolarity than glycerin.9

Refresh Optive Advanced (Allergan) incorporates carboxymethylcellu-

lose sodium 0.5%, glycerin 1% and polysorbate 80 0.5% as actives with castor oil, erythritol, levocarntine and carbomer copolymer type A as inactives. Systane Ultra (Alcon) uses polyethylene glycol 400 0.4% and propylene glycol 0.3% in conjunc-tion with HP-guar as an inactive. Retaine MGD (Ocusoft) contains light mineral oil 0.5% and mineral oil 0.5% as actives and a number of inactives (e.g., cetalkonium chloride, glycerol, poloxamer 188).

There can also be differences in pH and osmolarity, depending on the characteristics the company wants to exhibit. Systane Gel Drops (Alcon) fall at pH 7.0, while Systane Ultra (Alcon) falls at 7.8. A pH that more closely matches that of the pa-tient’s tears will result in less sting-ing on instillation and better overall comfort. Some tears are signifi cantly

hypoosmotic to the tear fi lm, which is around 305 mOsmols (for exam-ple, TheraTears is at 181 mOsmols), while others are isosmotic or just slightly hypoosmotic. In general, a tear that is relatively hypoosmotic to the tears of the patient will blunt the damaging effects of high osmolari-ty.10 Lowering osmolarity generally improves OSDI scores, with an increased effect in younger patients and those with hyperosmotic tears.

In addition to OTC eye drops, a number of companies have been

diligently working on the develop-ment of new prescription drugs for dry eye, but none have thus far met the criteria for approval. Dry eye treatment trials include subjective accounts of patient comfort, and the FDA is typically wary of using subjective data as a factor in its ap-

Preservative Concentration Range

Additional Eff ects (+/-)

• Benzalkonium chloride (BAK) 0.004% to 0.02%

• Increases drug penetration.• Extends product shelf life.• Disrupts tight junctions.• Accelerates epithelial desquamation.• Promotes apoptosis at low concentrations and necrosis at high concentrations.• Stimulates production of infl ammatory cytokines.• Reduces aqueous production.• Causes reversible and non-reversible neurotoxicity, reducing nerve fi ber density.

• Polyquaternium-1 0.001% • Causes superfi cial epithelial damage. Reduces the density of conjunctival goblet cells, which decreases aqueous tear fi lm production.

• Bacterial cells attract it, but human corneal epithelial cells tend to repel it.

• Sodium perborate • Vanishing preservative: Upon exposure to an aqueous environment, it is catalyzed into hydrogen peroxide, water and oxygen.

• Alters protein synthesis within bacterial cells by oxidizing cell membranes and altering membrane-bound enzymes, causing enzymatic inhibition.

• Stabilized oxychloro complex 0.005% • Degrades to water, oxygen, sodium and chlorine free radicals when exposed to light.• Chlorine free radicals are thought to inhibit microorganism protein synthesis within

cells by way of glutathione oxidation, which causes microbe cell death.• Broad antimicrobial activity—includes antibacterial, antifungal and antiviral eff ects.

• Sodium chlorite 0.005% • Mixture of 80% chlorite, 11% sodium chloride, water and trace electrolytes that breaks down into sodium and chloride ions, oxygen and water when exposed to light.

• Polyhexamethylene biguanide (PHMB)

0.02% • Benefi cial against bacteria and Acanthamoeba, however, its antifungal activity is limited. Lethally alters the transcription of bacterial DNA.

• Nonirritating to human corneal cells.• Integrates into bacterial cell walls, disrupting the membrane.

• Chlorobutanol • Alcohol that increases lipid solubility and is able to cross the bacterial lipid layer. Has extensive anti-bacterial action, causing cell lysis by disruption of microbial cell membrane lipid confi guration.

• Causes signifi cant keratitis and irritation to the ocular surface, but less than BAK.

• EDTA (edetate disodium or ethylene diamene tetraacetic acid)

1% • Chelating agent that binds metals, which inactivates them.• Enhances the activity of quaternary ammonium bases and sorbate.

Table 4. Approved Preservatives


proval process. For these and other reasons, Restasis (cyclosporine, Allergan) has remained the only prescriptive dry eye drug for over a decade. While others will eventually follow, until that time, it is import-ant to understand the difference in the inactive ingredients contained in OTC eye drops and make specifi c recommendation to your patients. Even a savvy ingredient-reading patient may not be able to make sound choices in eyedrop use simply by reading the package labeling, so offer informational packets in-offi ce, and discuss all potential complica-tions with other medications the patient may be taking. RCCL 1. Nichols KK, Foulks GN, Bron AJ, et al. The inter-national workshop on meibomian gland dysfunc-tion: executive summary. Invest Opthalmol Vis Sci, 2011;52:1922-9.2. Duncan K, Jeng BH. Medical management of blepharitis. Curr Opin Ophthalmol, 2015 Jul;26(4):289-94.

3. Rules and Regulations. Food and Drug Adminis-tration 21 CRF Parts 349 and 369. Federal Register 53(43)March 1988:7076-83.4. Brafman S, Eiden BS. Finding the balance for contact lens-associated dry eye. Review of Cornea and Contact Lenses. Jan 2012.5. Elder DP, Crowley PJ. Antimicrobial preserva-tives part one: choosing a preservative system. American Pharmaceutical Review. Jan. 2012. Avail-able: www.americanpharmaceuticalreview.com/Featured-Articles/38886-Antimicrobial-Preserva-tives-Part-One-Choosing-a-Preservative-System/.6. Freeman PD, Kahook MY. Preservatives in topical ophthalmic medications: historical and clinical per-

spectives. Expert Rev Ophthalmol. 2009:4(1):59-64.7. Bartlet JP, Jaanus SD. Clinical ocular pharmacol-ogy. 5th ed. Stoneham: Butterworth-Heinemann; 2007.8. Zheng LL, Myung D, Yu CQ, Ta CN. Comparative in-vitro cytotoxicity of artifi cial tears. JSM Ophthal-mology. 2015 Jan;3(1):1026.9. Montani G. Intrasubject tear osmolarity changes with two diff erent types of eyedrops. Optom Vis Sci. 2013 Apr:90(4):372-7.10. Corrales RM, Luo L, Chang EY, Pfl ugfelder SC. Eff ects of osmoprotectants on hyperosmolar stress in cultured human corneal epithelial cells. Cornea. 2008. Jun;27(5):574-9.

Is There Science Behind the Slogans?Ironically, while the FDA does not require studies to demonstrate effi cacy of drops based on its active ingredient list, the agency does require proof for advertising and marketing claims in the form of results from clinical studies or market research. Approved on-the-box statements like the following must have clinical trials or other data to back up the claim.

• #1 Doctor Recommended Brand.• Doctor Recommended.• Extended Protection.• High Performance.• Advanced Dual Action Formula.

• Clinically shown to improve tear fi lm stability.• Long-lasting relief.• Relief that lasts up to 8 hours.

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REALITY CHECK:Outdated FDA protocols don’t account for real-world usage, newer lens

materials and virulent organisms. Proposed updates could bring big changes.By Yvonne Tzu-Ying Wu, PhD, MPH, An Truong, B.Optom, and Fiona Stapleton, PhD

There has been a dramat-ic shift in contact lens disinfection solutions in the last decade, with multipurpose solutions

(MPS) largely replacing more traditional multiple-step systems consisting of separate cleaning and disinfecting liquids, or unpreserved saline in conjunction with chlo-rine-releasing tablets. Currently, over 90% of patients report use of an MPS for lens disinfection; hydrogen peroxide, polyhexam-ethylene biguanide (PHMB)-based and polyquaternium-1 (Polyquad)/myristamidopropyl dimethylamine (Aldox)-based systems are consid-ered the most commonly used.1,2

While use patterns have evolved, regulatory policy has lagged be-hind. Manufacturers must comply with FDA guidelines to obtain clearance for the sale of contact lenses and lens care products in the United States. The guide docu-ments in question—Premarket Notifi cation 510(k) Guidance Document for Daily Wear Contact Lenses and Guidance for Industry: Premarket Notifi cation 510(k) Guidance Document for Contact Lens Care Products—were published in 1994 and 1997, respectively. Due to subsequent updates in contact lens technolo-gy and reports of adverse health incidents, including widespread Acanthamoeba keratitis, these doc-uments have been deemed by many to be out of date.3-5

The Division of Ophthalmic and Ear, Nose and Throat Devices (DOED) has since suggested a number of changes to these doc-uments—namely, the addition of a test protocol to evaluate MPS effi cacy against Acanthamoebakeratitis. Other suggestions include the prevention of environmental contamination, particularly as a result of water contact, and the impact of contact composition on MPS effi cacy.2 For example, ionic charge, lens material porosity and relative hydrophobicity are mark-edly altered between traditional hydrogel lenses and newer silicone hydrogel lenses; these properties are known to impact microbial ad-hesion and the uptake and release of MPS preservatives, which may compromise disinfection effi cacy.6-9

This article provides an over-view of specifi c issues identifi ed with current MPS guidelines and standards applicable to MPS products sold in the United States. Proposed modifi cations raised by various expert bodies in an attempt to address these issues will also be discussed.

CONTACT LENS-RELATED ACANTHAMOEBAThese microorganisms exist commonly in freshwater and soil environments as either an active trophozoite or dormant cyst form, the latter of which is encased in a double-layer cellulose wall that enables it to withstand harsh en-

vironmental conditions, including exposure to extreme temperature, pH and dryness.3,4 As a result, they exhibit resilience to many forms of disinfection.3-5 Pathogenic organ-isms known as endosymbionts, which include Pseudomonas and mycobacterium, may also grow and replicate within the cytoplasm of Acanthamoeba, further enhanc-ing its virulence.6,12

Acanthamoeba keratitis (AK) is a rare but serious corneal infec-tion that is often sight-threatening despite medical interventions.

Beginning in June 2003, in-vestigators identifi ed increased outbreaks of the disease in the Chicago-Gary-Kenosha metropoli-tan area; consequentially, Complete Moisture Plus (AMO) was recalled in 2007 after a national inquiry found it resulted in an increased

Dr. Wu is a postdoctoral research fellow at the School of Optometry and Vision Science at the University of New South

Wales, Sydney, Australia.

Dr. Truong has been working in clinical practice for a decade. During this time she also gained a BSci and continued on to submit

a PhD at the school of Medicine at the University of

New South Wales, Sydney, Australia.

Dr. Stapleton is the head of the School of Optometry and Vision Science at the University of New South Wales, Sydney, Australia.

ABOUT THE AUTHORS

p28_RCCL0216_F4 FDA Testing.indd 28 1/27/16 4:18 PM


risk of Acanthamoeba keratitis.13,14 An elevated level of the disease continued to persist following the recall, however, suggesting the recalled MPS may not have been the sole culprit.7

Several subsequent studies have endeavored to elucidate the persistence of the Acanthamoeba infections post-recall.5,7-9,11,15

Additionally, a microbiology workshop involving the FDA, eye care professionals, microbiologists and members of industry convened in 2009 to discuss testing proto-cols for Acanthoamoeba disinfec-tion effi cacy.16 Below is a general overview of the testing parameters proposed at this meeting:

• What should be the challenge size for testing MPS in the absence of a contact lens?

• Which Acanthamoeba strains should be tested?

• How should the cells be grown in order to obtain cells in the tro-phozoite stage of growth?

• How should cells in the cyst stage be produced?

• How should the number of survivors of trophozoites or cysts be measured?

• What should be the protocol to use when testing for MPS effi cacy in the presence of a contact lens?

• What should the overall perfor-mance criteria be for the different possible test scenarios?

• Should the MPS’s ability to cause the Acanthamoeba cells to encyst be measured?

Other microbiological test meth-od workshops (one in May 2014; the latest in November 2014) have been held by the FDA following the 2009 meeting to accommodate fur-ther discussion of test parameters—namely, what strain of organism to cover, life cycle (both trophozoite and cyst stage), growth method and how to encyst Acanthamoeba?18-20,37

No consensus has been reached thus far regarding an appropriate microbiological test method for Acanthamoeba; however, sugges-tions of critical test parameters in-clude the use of least two different Acanthamoeba strains in cyst form and use of an inoculum size no greater than 1,000 to 10,000 cysts or trophozoites.

Release Date: February 2016

Expiration Date: February 1, 2019

Goal Statement: This course covers cur-rent FDA testing reguations and proposed changes.

Faculty/Editorial Board: Yvonne Tzu-Ying Wu, PhD, MPH, An Truong, B. Optom, and Fiona Stapleton, PhD

Credit Statement: COPE approval for 2 hours of continuing education credit is

pending for this course. Check with your state licensing board to see if this counts toward your CE requirements for relicen-sure.Joint-Sponsorship Statement: This contin uing education course is joint-spon-sored by the Pennsylvania College of Optometry.Disclosure Statement: Drs. Wu, Truong and Stapleton have no financial interest in any products mentioned in this article.

The increase in Acanthamoeba infection risk among contact lens wearers suggests a need for better FDA testing methods.

Photo: Christine W

. Sindt, OD

HOW FDA TESTINGFALLS SHORT




Research also indicated Acanthamoeba grown in the pres-ence of bacteria demonstrate less variability in their susceptibility to the MPS tested, as opposed to when grown axenically (i.e., in the absence of other microorganisms).21

Acanthamoeba cysts produced from growth on non-nutrient agar (known as the starvation method) are signifi cantly more resistant to disinfection by PHMB-based MPS compared with cysts induced by Neff’s encystment medium.21,22

Therefore, the microbiological and nutritional environment are both signifi cant factors in modifying cyst resistance, and the susceptibility of Acanthamoeba to biocides may vary depending on the experimen-tal conditions.

As manufacturers continue to evaluate MPS effi cacy against the test organisms, precise stan-dardized experimental protocols and conditions still need to be defi ned in order to obtain valid results from multiple sites. Further research is also still warranted to fi nalize a testing guideline for solu-tion effi cacy against the forms of Acanthamoeba likely to be encoun-tered in real world conditions.

LENS/SOLUTION INCOMPATIBILITYPreservative uptake—the ab-sorption of preservative from the solution within the lens case into the lens matrix—is evaluated based on the amount of preservative ab-sorbed from the solution in ques-tion at different points in time until a concentration plateau is obtained. Release describes the sequestration of preservative from the lens into an aqueous solution, such as the tear fi lm. Distinct factors that affect uptake and release include water content, charge, relative hydropho-bicity, surface treatment and poros-

ity of lens material, in conjunction with the concentration, charge, iconicity in the product matrix, mo-lecular weight and hydrophobicity of the care component.22 Variations in the adsorption of the solution components by lenses can lead to differences in the amount and rate of release onto the ocular surface; both can compromise disinfec-tion effi cacy of the solution (see, “Silicone Takes Over,” page 33).8,9

Preservative uptake and release are assessed for new solutions ac-cording to ISO11986, “Ophthalmic Optics—Contact Lenses and Contact Care Products—Determination of Preservative Uptake and Release,” which guides testing to determine if ocular irritation is likely to occur from preservative uptake and subsequent release.

At this time, preservative uptake is assessed by the International Standards Organization and is not currently required for FDA premarket testing of contact lenses and lens care products (see, “Going Global,” page 34). However, the FDA has proposed updates to its guidelines advising that manufac-turers demonstrate that represen-tative lenses do not decrease the concentration of preservative below the specifi ed concentration range when incubated in a care product solution. The proposed acceptance criterion is that preservative con-centration in the lens case should remain within the manufacturer specifi cations after the recom-mended soak time. Lenses that do not pass should be labeled as such on the product and packaging or subjected to additional disinfection effi cacy testing prior to approval for the US market. This is the fi rst time an acceptance criterion for preservative uptake will be intro-duced into the guidance.

In addition to concerns regard-ing compromised disinfection effi cacy, preservative uptake and release are critical determinants for solution-induced corneal toxicity. Despite being asymptomatic, a signifi cant proportion of contact lens wearers (i.e., 37% of subjects) that used a PHMB-based system displayed a level of staining consis-tent with the classic solution-based toxicity reaction.24 Studies have also reported an increased rate of corneal staining associated with several care systems in combination with silicone hydrogel materials.25,26

Several MPS systems were refor-mulated in an attempt to improve their compatibility with the newest lens materials in order to minimize staining potential. A clinical test matrix for silicone hydrogel lenses was also proposed by the FDA to address clinical performance.

However, some researchers have questioned whether staining has signifi cant clinical relevance, casting doubt on whether the FDA’s clinical test matrix is appropriately set up with adequate consideration of these clinical parameters.

LENS WEAR PATTERNSResearch groups continue to investigate if lens wear noncom-pliance may have contributed to a Fusarium outbreak in the United States and Singapore.27,28 The major noncompliant behaviors identifi ed thus far are: reuse of solutions, especially after lens storage; lack of a manual-rub cleaning step; overnight use of daily wear contact lenses; and the use of lenses past their recommended replacement date.28-30 Other research indicates poor hand washing and lack of understanding regarding proper use of lens care products are other sig-nifi cant noncompliance behaviors, among others.31-39

REALITY CHECK: HOW FDA TESTING FALLS SHORT



It has been suggested that solution testing should take into account such behaviors; however, many researchers agree testing for such an array of noncompliant behaviors and situations is nearly-impossible.

Artifi cial tear use may also have an impact on disinfection effi cacy.40

Certain artifi cial tear components may be used by infective microbes as a source of energy or to en-hance the growth of biofi lm on the contact lens surface.41-43 Handling a contact lens may also contaminate its surface with organic materi-al, which can neutralize certain disinfectants.44 ISO14729 does not require organic soil to be used when evaluating MPS disinfection; however, the September 2014 microbiology workshop yielded the

suggestions of adding an organic soil test (i.e., 1x107 to 1x108 CFU/mL heat-killed Saccharomyces cere-visiae yeast cells in heat-inactivated bovine serum) and an artifi cial tear component test (0.5% hen egg lysozyme, 0.1% porcine stomach mucin, human serum, 0.2% bovine serum albumin, 1% albumin, 0.1% mucin and 0.2% mucin) to the standard testing protocol. Additionally, recent research has found that conditioning bacteria to human tear fl uid or corneal epithelial cells may upregulate vir-ulence gene expression in bacteria, including those genes resistant to killing.45,46 Therefore, the antimi-crobial effi cacy of MPS against host-conditioned microbes may be reduced when compared with

non-conditioned laboratory stan-dard strains. Use of conditioned bacteria for ISO testing may better refl ect the actual MPS biocidal activity against bacteria likely to be encountered in situ.

While the inclusion of these parameters is expected to simulate a more realistic portrayal of daily lens wear and the factors that might complicate it, the obstacle once again becomes how to standardize such parameters, including how to ensure uniformity of human tear conditioning fl uid or appropriate incubation times for artifi cial tear interference testing. Thus, estab-lishing standard testing parameters and setting passing criteria requires further evaluation to adequately replicate real life conditions.

Traditional multipurpose disinfection solutions consist of di� erent components that combine to achieve various tasks required for contact lens care. Most MPS products are marketed as single solutions for cleaning, disinfection and storage purposes; each has a specifi c formulation, though the primary components typically remain the same. These include:

• Preservatives. These substances are responsible for killing microbes residing in and on the contact lenses and also inhibiting contamination of the MPS solution itself for prolonged use after opening.21 Preservative uptake and release profi les vary depending on the kind used in the MPS formulation, which can lead to di� ering disinfection e -cacies.15 Too much of a preservative released from the lens into the tear fi lm can also result in corneal toxicity.22 Common preservatives include polyhexamethylene biguanide hydro-chloride (PHMB), polyquaternium-1 (PQ-1), myristamidopropyl dimethylamine, hydrogen peroxide and polyaminopropyl biguanide.

• Surfactants. These are amphiphilic chemi-cals similar in nature to a detergent that aid in removal of loosely bound protein deposits of an inorganic or lipid nature.41 Due to the am-phiphilic nature of surfactants, they may po-tentially act as lubricants by reducing surface

tension.23 This increased wettability bu� ers interacting ocular tissues from hydrophobic areas on the surface of the contact lens.42 Typical MPS surfactants include isopropyl alcohol, sodium citrate, sodium phosphate, polyvinyl alcohol and sodium borate.

• Chelating Agents. These substances bind proteins and metals like calcium to prevent deposition on the contact lens surface.25 Ethylenediaminetetraacetic acid (EDTA) is the most common MPS chelating agent. EDTA has been shown to be an adjuvant that can enhance biocidal activity.69

• Bu� ers. Bu� ers help maintain the pH of the MPS to ensure biocompatibility a enhance comfort and reliability of the component agents. Common MPS bu� ers include borate, phosphate, bicarbonate, citrate and nitrate.21

• Wetting Agents and Lubricants. These decrease surface tension to increase the wet-ting angle of the contact lens surface, which leads to improved comfort of the contact lens via reduced friction between the contact lens and ocular surface and eyelids.21 Common wetting agents and lubricants include Tetron-ic 304, poly(oxyethylene)-poly(oxybutylene), hydroxypropyl methylcellulose, hyaluronic acid, carboxymethylcellulose and propylene glycol.

Inside the Bottle





Given the controversies, recom-mendations encourage manufac-turers to make evaluating MPS in the presence of contact lenses a standard, at least with respect to biocompatibility. Additionally, lens/solution incompatibilities should be labeled on the product and pack-aging to help contact lens wearers make an informed decision about their choice of lens care product. The FDA has also proposed incor-porating other specifi c parameters, including the addition of two new strains of Pseudomonas to the test panel and use of organic soil to refl ect real-life scenarios.

GP LENS CLEANINGIn some cases, contact lenses and lens cases act as vectors for microbes derived from the envi-ronment, delivering these micro-organisms to the ocular surface where complications may arise. Studies have identifi ed exposure of contact lenses to sources of water, including tap water, as risk factors for Acanthamoeba keratitis.47-53

However, while rinsing with tap water has long been advised against as part of the soft lens care regi-men, many GP lens care regimens continue to include use tap water for rinsing as part of their care process.15

The Centers for Disease Control (CDC) revised its Consumer Updates website in 2010 to convey the elimination of water for GP lens care, and the FDA published an addendum to the 510(K) con-tact lens care labeling guidance; However, some GP lens solutions continue to recommend its use, and many consumers remain unaware of the change.54,55 Potential alter-natives to tap water with GP lenses do exist—for example, sterile saline rinses—but the uptake of such options seems to be low.

The group also discussed a relat-ed issue regarding scleral contact lenses, which are typically insert-ed with a fl uid reservoir. Often, unpreserved saline is used, but tap water may also be used in some cases. While this may present sev-eral problems, it is not clear how common this practice is.

BIOFILM FORMATIONMicrobial phenotype and gene ex-pression can also affect a microbe’s susceptibility to disinfectants and thus the effi cacy of a solution. As mentioned previously, the physical form(s) of the organism have dif-fering biocide resistances. Bacteria conditioned with human tear fl uid or with epithelial cells may secrete factors that hinder biocidal activity. The low metabolism of bacteria re-siding in biofi lms may also increase their resistance to antibiotics and disinfectants.13,56,57

Many studies have reported that while some disinfecting solutions perform better than others in reducing planktonic bioburden, most were not effective in reducing biofi lm.17,58-61 One study shows that while planktonic organisms may be susceptible to PHMB- and Polyquad-based disinfecting solutions, the susceptibility of these same strains of bacteria con-tained in a biofi lm is considerably reduced.62

Additionally, microbial adhesion and biofi lm formation is enhanced in silicone hydrogel lenses com-pared with conventional hydrogel lenses.14 Researchers hypothesize this observation is due to the increased hydrophobic phases, increased protein/lipid deposits on silicone hydrogel lens and higher oxygen transmissibility/availabili-ty.63-66 Even though these observa-tions are mostly in vitro, further study regarding MPS effi cacy

against biofi lm should be consid-ered to warrant safe lens wear.

COMFORT AND CONVENIENCE Several MPS systems have been reformulated to improve their compatibility with silicone hydro-gel lens materials in an attempt to decrease corneal staining potential. In addition, manufacturers have tried to improve comfort for lens wearers by adding wetting agents. However, while wettability is relat-ed to improved lens wear comfort, the recalls of two MPS systems (Complete Moisture Plus and Renu with MoistureLoc) has been hypothesized to be the result of a combination of effects, including the addition of moisturizing agents for comfort.19,20 No isolated MPS component appears to be singularly responsible for enhanced rates of Acanthamoeba encystment and thus increased resistance to biocidal activity.67,68 The interaction of com-ponents within a formulation—biocide, buffer and moisturizing agent—appear to interplay, in a so-far unpredictable manner, to affect the eventual biocidal activity.67,68

It is diffi cult to fi nd the critical balance between improved wet-tability and solution disinfection effi cacy without compromising either. Further research is needed to carefully evaluate the balance between these factors for successful lens wear.

Members of the DOED plan to revise the 1994 guidance

document for daily wear contact lenses and the 1997 guidance document for lens care products to refl ect advancements in contact lens materials, microbial outbreak incidents and increased understand-ing of the pathogenesis of certain microbes such as Acanthamoeba.





Silicone hydrogel lenses (the fi rst genera-tion: balafi lcon A and lotrafi lcon A) were fi rst introduced to the market in the late 1990s, when manufacturers began to inject silicone polymers into the original hydrogel monomers to improve material performance (i.e., oxygen permeability, ion transport, deposit resistance and mechanical prop-erties).70 However, while silicone polymers allow high oxygen transmission, they are hydrophobic and thus require the hydrogel polymer water phase to allow transport of gases like oxygen and carbon dioxide, ions and tear fi lm components across the lens.

Additionally, the contrasting properties of the constituent materials of a silicone hydrogel lens result in signifi cantly di� erent lens surface characteristics compared to conventional hydrogel materials, including wettability, deposition of proteins and lipids and lens/solution interactions (e.g., uptake and release of preservative by the lens or biocide sequestration).71-74

A decades-old grouping system devel-oped over 20 years ago, based on contact

lens water content and charge, has proved e� ective for predicting potential solution incompatibilities with the varied range of poly(HEMA) lenses available on the market; however, similar incompatibilities could not be predicted when silicone hydrogel lenses were added to this conventional grouping system (Table 1). For example, the multi-purpose solution preservative Aldox, which features a positive charge and hydropho-bic tail, demonstrates strong interactions

with silicone hydrogel ma-terials—that is, all silicone hydrogel lenses, regardless of ionic charge and/or water content, uptake a greater amount of Aldox compared to poly(HEMA) contact lens-es.15,30,75 A silicone hydrogel material group was added to the classifi cation upon identifi cation of this issue and subdivided into fi ve subgroups to account for di� erences in poly(HEMA) content (Table 2).

Group Description

I Low Water Content (<50%), Nonionic*

II High Water Content (>50%), Nonionic*

III Low Water Content (<50%), Ionic*

IV High Water Content (>50%), Ionic*

*Being ionic in pH = 6.0 – 8.0.

Table 1. Conventional Hydrophilic Material Groups

Group Description

V-A No Water Specifi cation, Ionic*

V-B High Water Content (>50%), Nonionic*

V-C Low Water Content (<50%), Nonionic*, Hydrophilic-monomer Only

V-Cm Low Water Content (<50%), Nonionic*, Surface Treated (ST)

V-Cr Low Water Content (<50%), Nonionic*, Non-ST, Semi-interpenetrating Network

*Being ionic in pH = 6.0 – 8.0.

Table 2. Silicone Hydrophilic Material Groups

Key issues include consideration of new organisms and lens materials in the test panel, lens/solution in-compatibility concerns, real-world factors and clearer labeling for GP lens products.

Additionally, future emphasis is expected to be placed on whether

MPS manufacturers should account for noncompliance in their premar-ket testing. Clear and consistent in-structions for contact lens and lens case hygiene also remain a critical measure that should be considered. Overall, it is anticipated that revi-sion of the ISO18259 standard will

have a signifi cant impact on MPS safety and the contact lens market; the specifi c repercussions remain to be seen. RCCL

Editor’s note: Thank you to Dr. Nicole Carnt of the Save Sight Institute, University of Sydney, for peer reviewing this article.

Silicone Takes Over




In most countries, an MPS must meet the International Organiza-tion for Standardization (ISO) disinfection criteria before it can obtain licensing, prior to any specifi c country requirements. There

are two pathways to obtain ISO classifi cation, specifi ed by ISO 18259 (Figure 1).26 The fi rst is for a solution to satisfy the prima-ry criteria of a stand-alone test; that is, the solution must have a greater than or equal to 3-log re-duction (i.e. 1,000 times smaller than the original amount) in each of the three test bacteria and a greater than or equal to 1-log kill (i.e. 10 times smaller than the original amount) in each of the test fungi. The secondary criteria for the stand-alone test is that the solution must demonstrate the concentration of each of the three bacterial species is reduced by 1 log unit at minimum, and that the sum of the log reduc-

tions of the three bacteria exceeds 5 log units. Supplementing the less stringent secondary criteria of the stand-alone test is the regimen test, which requires the solution reduce microbe numbers to a certain level after a lens rubbing and rinsing process. The specifi c standards for antimicrobial activity and test microbes specifi ed by ISO18259 are detailed in Table 3.27

Microbe TypeTest Fusarium

solani (ATCC 36301)

Candida albicans (ATCC 10231)

Pseudomonas aeruginosa (ATCC 9027)

Serratia marcescens (ATCC 13880)

Staphylococcus aureus (ATCC 6538)

Stand-alone Test (Primary Criteria)

1.0 log unit

1.0 log unit

3.0 log unit 3.0 log unit 3.0 log unit

Stand-alone Test (Secondary Criteria)

Stasis at the soaking time

Stasis at the soaking time

Minimum 1.0 log unit



Sum of the log reductions of the three challenge bacteria must exceed 5.0 log units.

Regimen Test (Includes all mfg. recommended procedures, including rub/rinse.)

<10CFU on lens

<10CFU on lens

<10CFU on lens

<10CFU on lens

<10CFU on lens

ATCC: American Type Culture Collection; CFU: colony forming units* Based on average reduction at manufacturer’s recommended disinfection time.

Stand AloneTest

RegimenTest

Test Failed

Stand AloneTest Passed

Regimen TestPassed

PrimaryCriteria Met

SecondaryCriteria Met

No No

YesYes

Yes

RegimenCriteria Met Test Failed

No

Fig. 1. Flow chart for Stand-alone and Regimen Tests specifi ed by ISO 18259.18

1. Morgan PB, Efron N. A decade of contact lens prescribing trends in the United Kingdom (1996-2005). Cont Lens Anterior Eye 2006; 29: 59-68.2. Woods CA, Morgan PB. Use of silicone hydrogel contact lenses by Australian optom-etrists. Clinical and Experimental Optometry. 2004;87:19-23.3. FDA. FDA Executive Summary. Prepared for the May 13, 2014 Meeting Contact Lens and Care Product Guidance Documents. In: Devic-es ODPotM, Committee A eds, 2014.4. FDA. Bausch & Lomb Global Recall of ReNu with MoistureLoc Contact Lens Cleaning Solution. In, 2006.5. Yoder JS, Verani J, Heidman N, et al. Acan-thamoeba keratitis: the persistence of cases following a multistate outbreak. Ophthalmic Epidemiol. 2012;19:221-225.6. Willcox MD. Microbial adhesion to silicone hydrogel lenses: a review. Eye Contact Lens. 2013;39:61-66.7. Hutter JC, Green JA, Eydelman MB. Pro-posed silicone hydrogel contact lens grouping system for lens care product compatibility testing. Eye Contact Lens. 2012;38:358-62.8. Rosenthal RA, Dassanayake NL, Schlitzer RL, et al. Biocide uptake in contact lens-es and loss of fungicidal activity during storage of contact lenses. Eye Contact Lens. 2006;32:262-266.9. Rosenthal RA, McDonald MM, Schlitzer RL, et al. Loss of bactericidal activity from contact lens storage solutions. CLAO J 1997;23:57-62.10. Keay L, Stapleton F, Schein O. Epidemiol-ogy of contact lens-related infl ammation and microbial keratitis: a 20-year perspective. Eye Contact Lens. 2007;33:346-53, discussion 362-343.11. Fiona S, Lisa K, Katie E, et al. The inci-dence of contact lens-related microbial keratitis in australia. Ophthalmology. 2008 Oct:115(10):1655-62.12. Carnt N, Stapletion F. Strategies for the pre-vention of contact lens-related Acanthamoeba keratitis: a review. Ophthalmic and physiologi-cal optics. 2015 Dec 21.13. Joslin CE, Tu EY, Sho¥ ME, et al. The association of contact lens solution use and acanthamoeba keratitis. Am J Ophthalmol 2007;144:169-180.e162.14. Joslin CE, Tu EY, McMahon TT, et al. Epide-miological Characteristics of a Chicago-area Acanthamoeba Keratitis Outbreak. Am J Ophthalmol 2006 Aug;142(2):212-7.15. Green AJ, Phillips SAK, Hitchins VM, et al. Material properties that predict preservative uptake for silicone hydrogel contact lenses. Eye & Contact Lens 2012;38:350-357.16. Willcox M. Acanthamoeba testing for mul-tipurpose disinfecting solutions. Contact Lens update, 2009.17. Imayasu M, Tchedre KT, Cavanagh HD. Ef-fects of multipurpose solutions on the viability and encystment of Acanthamoeba deter-mined by fl ow cytometry. Eye Contact Lens. 2013;39:228-233.18. Ahearn DG, Simmons RB, Ward MA, Stult-ing RD. Potential resistant morphotypes of Acanthamoeba castellanii expressed in multi-purpose contact lens disinfection systems. Eye Contact Lens 2012;38:400-5.19. Legarreta JE, Nau AC, Dhaliwal DK. Acan-thamoeba keratitis associated with tap water

Table 3. Criteria for the Stand-alone and Regimen Tests for Contact Lens Disinfecting Solutions

Going Global




use during contact lens cleaning: manufac-turer guidelines need to change. Eye Contact Lens 2013;39:158-61.20. Boost M, Shi GS, Cho P. Adherence of acanthamoeba to lens cases and e� ects of drying on survival. Optom Vis Sci 2011;88:703-7.21. SJ Gromacki, Ward M. Understanding Contemporary Contact Lens Care Products. Contact Lens Spectrum 2013;28:20-25.22. Gorbet M, Postniko� C. The impact of silicone hydrogel-solution combinations on corneal epithelial cells. Eye Contact Lens 2013;39:42-47.23. Jones L, Powell CH. Uptake and release phenomena in contact lens care by silicone hydrogel lenses. Eye Contact Lens 2013;39:29-36.24. Rao SK, Lam PT, Li EY, et al. A case series of contact lens-associated Fusarium keratitis in Hong Kong. Cornea 2007;26:1205-9.25. Willcox M. Review of recent recalls of con-tact lens multipurpose disinfecting solutions. In. Contact Lens Update, 2007.26. Ahearn DG, Zhang S, Stulting RD, et al. Fusarium keratitis and contact lens wear: facts and speculations. Med Mycol. 2008;46:397-410.27. Chang DC, Grant GB, O’Donnell K, et al. Multistate outbreak of Fusarium keratitis associated with use of a contact lens solution. JAMA. 2006;296:953-3.28. Levy B, Heiler D, Norton S. Report on test-ing from an investigation of fusarium keratitis in contact lens wearers. Eye Contact Lens 2006; 32:256-61.29. Morgan PB, Efron N, Toshida H, Nichols JJ. An international analysis of contact lens compliance. Contact Lens and Anterior Eye 2011;34:223-28.30. Asbell PA, Dunn MJ, Schechter CB, et al. Compliance in the care of disposable contact lenses: the e� ect of patients’ health beliefs. CLAO J 1993 Jul;19(3):150-2.31. Claydon BE, Efron N. Non-compliance in contact lens wear. Ophthalmic Physiol Opt 1994;14:356-364.32. Collins M, Shuley V, Coulson J, Bruce A. Initial compliance with lens care instruc-tions. Clinical & Experimental Optometry 1993;76:115-118.33. Collins MJ, Carney LG. Patient compliance and its infl uence on contact lens wearing problems. American journal of optometry & physiological optics. 1986;63:952-61.34. Dumbleton K, Richter D, Woods C, et al. Compliance with contact lens replacement in Canada and the United States. Optom Vis Sci. 2010;87:131-39.35. Hay J, Munro F, Seal D. Testing contact lens wearer hygiene compliance. Optician 1995;209:26-29.36. Mayers M, Callan B, Borazjani R. Com-pliance and contamination in contact lens wear. American Academy of Optometry 2010: Program Nr:105090.37. Hildebrandt C, Wagner D, Kohlmann T, Kramer A. In-vitro analysis of the microbicidal activity of 6 contact lens care solutions. BMC Infect Dis 2012;12:241.38. Pinna A, Usai D, Zanetti S. Pseudomonas aeruginosa growth in Refresh Plus(R). J Ocul Pharmacol Ther. 2011;27:561-564.39. Yadav MK, Chuck RS, Park CY. Composi-

tion of artifi cial tear solution a� ects in vitro Pseudomonas aeruginosa biofi lm formation on silicone hydrogel lens. J Ocul Pharmacol Ther. 2013;29:591-4.40. Dutta D, Cole N, Willcox M. Factors infl u-encing bacterial adhesion to contact lenses. Mol Vis. 2012;18:14-21.41. Gorscak JJ, Ayres BD, Bhagat N, et al. An outbreak of Fusarium keratitis associated with contact lens use in the northeastern United States. Cornea 2007;26:1187-94.42. Khor WB, Aung T, Saw SM, et al. An outbreak of Fusarium keratitis associated with contact lens wear in Singapore. JAMA 2006;295:2867-73.43. Rao SK, Lam PT, Li EY, et al. A case series of contact lens-associated Fusarium keratitis in Hong Kong. Cornea 2007;26:1205-9.44. Lindsay RG, Watters G, Johnson R, et al. Acanthamoeba keratitis and contact lens wear. Clin Exp Optom. 2007;90:351-60.45. Radford C, Lehmann O, Dart J. Acan-thamoeba keratitis: Multicentre survey in England 1992-1996. British Journal of Ophthal-mology. 1998;82:1387-92.46. Jeong HJ, Yu HS. The role of domestic tap water in Acanthamoeba contamination in contact lens storage cases in Korea. Korean J Parasitol. 2005;43:47-50.47. Watt K, Swarbrick HA. Microbial keratitis in overnight orthokeratology: Review of the fi rst 50 cases. Eye Contact Lens 2005;31:201-8.48. Visvesvara GS. Epidemiology of infec-tions with free-living amebas and laboratory diagnosis of microsporidiosis. Mt Sinai J Med. 1993;60:283-8.49. Moore MB, McCulley JP, Newton C, et al. Acanthamoeba keratitis: A growing problem in soft and hard contact lens wearers. Ophthal-mology 1987;94:1654-1661.50. Woodru� S, Dart J. Acanthamoeba kera-titis occurring with daily disposable contact lens wear. British Journal of Ophthamology. 1999;83:1088-95.51. Prevention CfDCa. Parasites - Acanthamoe-ba - Granulomatous Amebic Encephalitis (GAE); Keratitis. In, 2010.52. Prevention CfDCa. Parasites - Acan-thamoeba - Granulomatous Amebic Encepha-litis (GAE); Keratitis. In, 2012.53. Saw SM, Ooi PL, Tan DTH, et al. Risk fac-tors for contact lens-related Fusarium keratitis: a case-control study in singapore. Arch Oph-thalmol. 2007; 125: 611-617.54. Clarke DW, Niederkorn JY. The pathophys-iology of Acanthamoeba keratitis. Trends Para-sitol. 2006; 22: 175-180.55. Aksozek A, McClellan K, Howard K, et al. Resistance of Acanthamoeba castellanii cysts to physical, chemical and radiological condi-tions. J Parasitol 2002;88:621-23.56. Kobayashi T, Higuchi-Watanabe N, Shiraishi A, et al. Mirafl ow, Soft Contact Lens Cleaner: Activity Against Acanthamoeba Spp. Eye Contact Lens 2015;41:240-4.57. Padzik M, Chomicz L, Szafl ik JP, et al. In vitro e� ects of selected contact lens care solutions on Acanthamoeba castellanii strains in Poland. Exp Parasitol. 2014;145 Sup-pl:S98-S101.58. Iovieno A, Ledee DR, Miller D, Alfonso EC. Detection of bacterial endosymbionts in clin-ical Acanthamoeba isolates. Ophthalmology 2010;117:445-452, e441-443.

59. Siddiqui R, Khan NA. War of the microbial worlds: who is the benefi ciary in Acanthamoe-ba-bacterial interactions? Exp Parasitol. 2012; 130: 311-313.60. Giraldez MJ, Resua CG, Lira M, et al. Contact lens hydrophobicity and roughness e� ects on bacterial adhesion. Optom Vis Sci. 2010;87:e426-31.61. Bruinsma GM, van der Mei HC, Busscher HJ. Bacterial adhesion to surface hydrophilic and hydrophobic contact lenses. Biomaterials. 2001;22:3217-24.62. Butrus SI, Klotz SA. Contact lens surface deposits increase the adhesion of Pseudomo-nas aeruginosa. Curr Eye Res. 1990;9:717-24.63. Kodjikian L, Casoli-Bergeron E, Malet F, et al. Bacterial adhesion to conventional hydro-gel and new silicone-hydrogel contact lens materials. Graefes Arch Clin Exp Ophthalmol. 2008;246:267-73.64. Sho� ME, Eydelman MB. Strategies to optimize conditions for testing multipurpose contact lens solution e© cacy against Acan-thamoeba. Eye Contact Lens 2012;38:363-7.65. Kilvington S, Lam A. Development of standardized methods for assessing biocidal e© cacy of contact lens care solutions against Acanthamoeba trophozoites and cysts. Invest Ophthalmol Vis. 2013 Jul;54(7):4527-37.66. Stapleton F, Stretton S, Papas E, et al. Sil-icone hydrogel contact lenses and the ocular surface. Ocular Surface. 2006:24-43.67. Orsborn G, Venkatesh S. Contact lens maintenance: lens care solutions and compli-ance. In. Mivision, 2012.68. Hui A, Boone A, Jones L. Uptake and release of ciprofl oxacin-HCl from conventional and silicone hydrogel contact lens materials. Eye Contact Lens 2008;34:266-71.69. Tian X, Iwatsu M, Sado K, Kanai A. Studies on the uptake and release of fl uoroquinolo-nes by disposable contact lenses. CLAO J 2001;27:216-20.70. Karlgard CC, Wong NS, Jones LW, Moresoli C. In vitro uptake and release studies of ocular pharmaceutical agents by silicon-containing and p-HEMA hydrogel contact lens materials. Int J Pharm 2003; 257: 141-51.71. FDA. US. Ophthalmic Devices Panel Meet-ing [online transcript]. In: HEALTH CFDAR, COMMITTEE MDA eds, 2014.72. Powell CH, Lally JM, Hoong LD, et al. Lipo-philic versus hydrodynamic modes of uptake and release by contact lenses of active entities used in multipurpose solutions. Cont Lens Anterior Eye. 2010;33:9-18.73. Jones L, Macdougall N, Sorbara GL. As-ymptomatic corneal staining associated with the use of balafi lcon silicone-hydrogel contact lenses disinfected with a polyaminopropyl biguanide-preserved care regimen. Optom Vis Sci. 2002;79:753-61.74. Carnt N, Jalbert I, Stretton S, et al. Solution toxicity in soft contact lens daily wear is asso-ciated with corneal infl ammation. Optom Vis Sci. 2007;84:309-15.75. Andrasko G, Ryen K. Corneal staining and comfort observed with traditional and silicone hydrogel lenses and multipurpose solution combinations. Optometry 2008;79:444-54.76. Rosenthal RA, Sutton SV, Schlech BA. Review of standard for evaluating the e� ec-tiveness of contact lens disinfectants. PDA J Pharm Sci Technol. 2002;56:37-50.






1. Under FDA criteria, for contact lenses to be designated as being ionic, the pH must fall between:

a. 6.0 and 8.0.b. 5.0 and 7.0.c. Anything lower than tear film pH.d. There is no pH requirement for “ionic” designation at FDA.

2. Preservative uptake and release by contact lenses is influenced by all of the following except:

a. The type of preservative in the MPS used to disinfect lenses.b. The pore size and water content of the lens material worn.c. The contact lens case used for storage.d. All of the above influence preservative uptake and release.

3. Which of the following is a contact lens solution-related compliance concern?

a. Wearing lenses beyond the recommended wearing time.b. Washing hands before handling lenses.c. Topping-off or re-using MPS.d. B and C are correct.

4. The FDA will most likely do the following in the next guidance document revision:

a. Add “real world” testing measures such as organic soil.b. Add the number of days a lens can be worn for extended or continuous wear.c. Add Acanthamoeba and possibly other organisms to the test panel.d. A and C are correct.

5. Biofilms allow various organisms to communicate with one another. The main concern regarding biofilms is that they:

a. Hinder disinfecting solution efficacy.b. Promote human corneal epithelial apoptosis.c. Decrease tear film pH, thereby decreasing all-day lens comfort.d. Increase the metabolism of resident bacteria, making the strain more

resistant to treatment.

6. In the FDA guidelines for Stand-alone Testing, the log reduction requirement for Acanthamoeba is:

a. 3 log reduction.b. 1 log reduction.c. 4 log reduction.d. There is no requirement for Acanthamoeba in the Stand-alone Test series.

7. Which of the following is not a documented risk factor for Acanthamoeba keratitis?

a. Topping off or re-using solutions.b. Swimming or showering in contact lenses.c. Being an adapted/veteran lens wearer.d. Forgetting to rub lenses after removal.

8. Buffers in contact lens solutions are used for which of the following?a. Maintaining the desired pH of the solution.b. Removing deposits and bacterial load.c. Binding proteins.d. All of the above are correct.

9. Which of the following best describes the rate of Acanthamoeba keratitis incidence following the 2007 MPS solution recall?

a. The rate steadily decreased after 2009 as a result of the recall.b. The rate initially decreased after the recall to the recalled solution pre-

launch level, but has increased beyond that point since 2009.c. No outbreak was noted prior to 2007, so this question is not appropriate.d. The rate remained the same until today as it was in 2007.

10. Silicone hydrogels differ from conventional hydrogel lenses by which of the following characteristics?

a. Ionic charge.b. Hydrophobicity.c. Material pore size.d. All of the above are correct.

11. The FDA panel of organisms in Stand-alone Testing (Primary Criteria) includes all of the following, except:

a. Pseudomonas aeruginosa.b. Serratia marcescens.c. Acanthamoeba castellani.d. Fusarium solani.

12. The role of the preservative in contact lens solutions is which of the following? a. Disinfecting a lens.b. Inhibiting contamination of the MPS solution when used for prolonged

periods of time.c. Serving as a natural buffer for the tear film.d. A and B are correct.

13. Microbial susceptibility to various disinfectants is influenced by which of the following?

a. Microbial strain.b. Level of bioburden.c. Microbial phenotype.d. All of the above are correct.

14. Acanthamoeba has a significant ability to survive when challenged by disinfection. Which of the following are accurate statements relating to Acanthamoeba and solution disinfection?

a. Acanthamoeba has an innate ability to regulate its pH by osmotic means to survive when exposed to MPS.

b. Acanthamoebae can encyst when challenged by cell crowding, reduced pH and sometimes even MPS exposure.

c. Only Acanthamoeba cysts infect corneal tissue, so it doesn’t matter that they can survive when exposed to MPS.

d. Pre-cystic Acanthamoebae are much easier to kill than trophozoites with MPS.

15. Alternatives to using water with GP lenses include all of the following, except: a. Only fit patients with scleral lenses, obviating the need to use tap water

when inserting GP lenses.b. Use sterile hospital or inhalation saline (0.9%) as a rinse.c. Rinse the cleaner off with MPS and insert directly from an approved

conditioning solution.d. A and B are correct.

16. The Fusarium keratitis outbreak of 2006 resulted in a voluntary solution recall. Which of the following related statements are accurate?

a. The strain of Fusarium responsible for the outbreak was from Group IV and did not relate to any water vector.

b. Re-use of this solution reduced the recalled MPS’s biocidal efficacy and was sequestered over time, posing increased risk to the patient.

c. The isolates evaluated were clonal, and related infections were probably due to contamination that occurred at the manufacturing plant.

d. The rate of infection was extremely high compared with the 2007 Acanthamoeba outbreak.

17. In addition to organic soil, which factor may ultimately contribute to infection and reduced MPS efficacy?

a. Wearing of lenses overnight while taking aspirin.b. Use of certain brands of artificial tears while wearing contact lenses.c. Running of a marathon while wearing lenses.d. Use of certain brands of facial moisturizers.

18. Which of the following material properties is not important in classification of silicone hydrogels?

a. Water content.b. Ionicity.c. Surface treatment (i.e., wettability, deposition characteristics).d. All are important factors to consider when classifying these lenses, since

they are uniquely different than conventional hydrogel lenses.

19. Which of the following statements on testing MPS efficacy against protozoa are true?

a. Infection rates are so low that it’s impossible to determine the species responsible for most infections.

b. It’s uncertain as to what inoculum size is ideal for testing, since we don’t have data that translates easily to infection potential.

c. Axenic growth of Acanthamoeba with a certain number of passes will show different resistance patterns to MPS than those organisms that are not “bacterized.”

d. B and C are true.

20. Which of the following is true regarding the Regimen Test (ISO18259)?a. It’s generally considered a more stringent test than the secondary criteria of

the Stand-alone Test.b. It does not require using a rub and rinse phase.c. It uses a designated log cut-off.d. It includes Acanthamoeba in its panel of organisms tested.

CE TEST ~ FEBRUARY 2016


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RCCLREVIEW OF CORNEA & CONTACT LENSES

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EXAMINATION ANSWER SHEET

Reality Check: How FDA Testing Falls Short

Valid for credit through February 1, 2019

Online: This exam can also be taken online at www.reviewofcontactlenses.com. Upon passing the exam, you can view your results immediately. You can also view your test history at any time from the website.

Directions: Select one answer for each question in the exam and completely darken the appropriate circle. A minimum score of 70% is required to earn credit.

Mail to: Jobson Optometric CE, Canal Street Station, PO Box 488 New York, NY 10013.

Payment: Remit $35 with this exam. Make check payable to Jobson Medical Information LLC.

Credit: COPE approval for 2 hours of CE credit is pending for this course.

Sponsorship: Joint-sponsored by the Pennsylvania College of Optometry.

Processing: There is an eight-to-10 week processing time for this exam.

Answers to CE exam: 1. A B C D 6. A B C D 11. A B C D 16. A B C D

2. A B C D 7. A B C D 12. A B C D 17. A B C D




Evaluation questions (1=Excellent, 2=Very Good, 3=Good, 4=Fair, 5=Poor)Rate the effectiveness of how well the activity: 21. Met the goals of the statement: 1 2 3 4 5

22. Related to your practice needs: 1 2 3 4 5

23. Will help improve patient care: 1 2 3 4 5

24. Avoided commercial bias/influence: 1 2 3 4 5

25. How do you rate the overall quality of the material? 1 2 3 4 5

26. Your knowledge of the subject increased: Greatly Somewhat Little 27. The difficulty of the course was: Complex Appropriate Basic

28. How long did it take to complete this course? ____________________

29. Comments on this course: ______________________________________

30. Suggested topics for future CE articles: ____________________________

Identifying information (please print clearly):

First Name

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Email

The following is your: Home Address Business Address

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Fax # - - By submitting this answer sheet, I certify that I have read the lesson in its entirety and completed the self-assessment exam personally based on the material presented. I have not obtained the answers to this exam by fraudulent or improper means.

Signature: ____________________________________ Date: ____________

Please retain a copy for your records. LESSON 112268, RO-RCCL-0216



By Robert Ensley, OD, and Heidi Miller, OD The GP Experts


Are you up to date on pairing GP lenses and solutions? Here’s a look at what makes a perfect match.

Good Chemistry

Gas permeable (GP) contact lens per-formance is highly dependent on the quality of the lens

surface. A clean, wettable lens allows for both a higher degree of vision clarity and better patient comfort. Accordingly, proper care of GP lenses is instrumental in ensuring successful wear.

With the variety of cleaning products available, however, it’s no wonder many patients become confused regarding which solu-tions to use. To help differentiate, let’s take a moment to review the fundamental components of successful GP lens care: surface cleaning and disinfection.

SURFACE CLEANINGEarly GP lenses were manufac-tured with silicone/acrylate copo-lymers to increase oxygen per-meability, resulting in negatively charged hydrophobic lens surfaces that attract positively-charged pro-teins and lipids. Modern GP lenses added fl uorine (fl uorosilicone/acrylate) to the mix, resulting in a lower surface tension that reduces deposit adherence and increases surface wettability for greater ease of lens cleaning.1

Most GP cleaners incorporate surfactants, compound molecules with a hydrophilic head and hydrophobic tail that surround lens contaminants like proteins, lipids and cosmetic-related debris to form a micelle. This molecule is then solubilized in solution and rinsed away in combination with digital pressure and friction.

GP cleaners that contain abra-sive surfactants like the Original Formula Boston Cleaner (Bausch + Lomb) and the now-discontinued Opti-Clean II (Alcon) are tradi-tionally more effective when used with lower-Dk, early-generation GP lenses that bind more protein. Newer cleaners including Boston Advance Cleaner (Bausch + Lomb) and Opti-Free Daily Cleaner (Alcon) use smaller-diameter abra-sive particles; however, these are still classifi ed as mildly abrasive and should be used with caution on higher Dk GP lenses, as they can scratch the surface and induce minus power to the lens by re-ducing center thickness.2 Abrasive cleaners are also contraindicated for use with any GP lens that is plasma treated. If a non-abrasive daily cleaner is required, Optimum Extra Strength Cleaner (Lobob Laboratories), a preservative-free formula, can be used.

Other daily cleaners include the isopropyl alcohol-based Sereine Extra Strength Cleaner (Optikem International) and Walgreens

Extra Strength Daily Cleaner. Both contain the same ingredients as the MiraFlow (Alcon) daily cleaner that was discontinued in 2010. Note, the original MiraFlow formulation was recently pur-chased by an independent prac-titioner and is distributed online only through a direct-to-consumer website.

Patients who are heavy protein depositors may benefi t from an additional enzymatic or solvent cleaner that can be used periodi-cally. Current enzymatic cleaners come in liquid form, allowing them to be added directly to a storage solution. Boston One-Step Enzymatic Cleaner (Bausch + Lomb) is recommended for weekly use, while SupraClens Daily Cleaner (Alcon) is recommended for every day use.

Formerly an in-offi ce cleaner only, Progent (Menicon) incorpo-rates a mixture of sodium hypo-chlorite and potassium bromide to remove proteins and is recom-mended for use on a biweekly basis. Because this formulation

What is Plasma Treating?Plasma is a gas that is ionized into a mixture of highly reactive neg-atively and positively charged particles. During treatment, GP lenses are placed in a vacuum chamber, where oxygen plasma breaks up and removes surface contaminants including grease, lipids and other residues. This process improves the lens’ initial wettability and com-fort by reducing the wetting angle.

Plasma treating should be thought of as a “deep clean” process rather than a coating treatment. Lenses with a plasma treatment are shipped hydrated, so excessive handling should be avoided prior to dispensing. Although the plasma treatment will wear o� over time, abrasive cleaners are not recommended for use to avoid accelerat-ing the breakdown. Most laboratories recommend cleaning the lens with Boston Simplus (Bausch + Lomb), Unique pH (Menicon) or a hydrogen peroxide-based solution.

p38_RCCL0216_PSP_GPE.indd 38 1/27/16 4:17 PM


is essentially bleach, it is recom-mended only for patients who fully understand how to use it properly.

In general, lenses should not soak in any of these liquids for more than 30 minutes, to avoid discoloration. Less frequent use of an enzymatic cleaner or Progent may be suffi cient for lenses containing fl uorosilicone/acrylate materials.

Following use of daily clean-ers, GP lenses should be rinsed thoroughly prior to lens insertion. While many GP wearers rinse with tap water, this is controversial. To reduce the risk of microbial expo-sure, rinsing with a sterile saline or multipurpose solution is typically recommended.

DISINFECTION AND STORAGEOnce the lens surface has been cleaned, a GP lens should be soaked overnight. Depending on the storage method, the lens is dis-infected using either preservatives or hydrogen peroxide. There are several preservatives used in GP solutions that are either bacteri-cidal or bacteriostatic in nature. These typically have larger molec-ular weights, limiting their ability to bind to a GP lens. Common preservatives include clorhexidine gluconate, benzyl alcohol, poly-quaternarium-1 (polyquad) and biguanides.

The Boston Conditioning Solution and Boston Advance Formula Conditioning Solution (Bausch + Lomb) are both pack-aged independently, but are part

of a two-bottle system with their daily-cleaning counterparts. Both solutions use clorhexidine gluco-nate 0.003% as a preservative, and contain polyvinyl alcohol (PVA) and a cellulosic viscosifi er to coat the lens surface, providing both moisture and a cushioning effect for added comfort. The Advance Formula Solution has an added preservative, polyaminopro-pyl biguanide 0.0005% (PAPB), and derivatized polyethylene gly-col as an additional wetting agent.

Other solution options for cleaning, disinfecting and storage (CDS) include Optimum CDS (Lobob) and MeniCare CDS (Menicon). Both solutions use the same formulation with lauryl sulfate salt of imidazoline and octylphenoxypolyethoxyethanol to clean the lens, and are preserved with benzyl alcohol 0.3% and edetate disodium 0.5%. Both CDS solutions recommend a rub and rinse prior to overnight soak, and

should be thoroughly rinsed prior to lens insertion. Optimum CDS can be purchased independently or as part of a combined care system kit with the Optimum ESC and Optimum wetting/rewetting drops.

If a patient develops a pre-servative sensitivity, hydrogen peroxide-based solutions can be used as an alternative. Solutions containing a 3% hydrogen per-oxide concentration are partic-ularly effective against multiple pathogens, including bacteria, viruses, fungi and protozoa, as peroxide produces free radicals that can penetrate a microbe’s cell membrane and destroy its DNA. However, the solution’s pH of 4.0 means that a neutralization step is also required prior to lens placement on the ocular surface. Additionally, because hydrogen peroxide cannot penetrate the matrix of GP lens, as it can a soft hydrogel, GP lenses still require a

Deposits on a hybrid contact lens.

(Continued on page 41)



By Elyse L. Chaglasian, OD, and Tammy Than, MS, OD Pharma Science & Practice

Dextenza on DeckCould the latest approach to steroid therapy conquer noncompliance once and for all?

Topical medication com-pliance is an ongoing struggle for many opto-metric practices today. Patients report issues

with frequency of administration, cost of medication and associated side effects of instillation (e.g., stinging, hyperemia), while practi-tioners struggle with lack of patient adherence. Since the process of ensuring medications are adequate-ly taken can be frustrating for all those involved, researchers contin-ue to search for newer and better ways to deliver therapeutic doses of medicine via simpler methods.

Dextenza (sustained-release dexamethasone 0.4mg, Ocular Therapeutix) aims to provide a new way to deliver steroid therapy. Rather than administering a drop or injection, an intracanalicular depot is inserted into the puncta to provide a one-month tapered release of preservative-free med-ication to the ocular surface. At the end of 30 days, the biodegrad-able hydrogel depot is absorbed by the body, eliminating the need for removal. Ocular Therapeutix is evaluating the use of Dextenza in various conditions, including allergic conjunctivitis, postopera-tive pain and infl ammation, and infl ammatory-related dry eye. Below, let’s examine these condi-tions individually.

ALLERGIC CONJUNCTIVITISThe initial Phase III clinical trial for Dextenza in the fall of 2015 yielded mixed results. While it did meet the primary endpoint of relieving ocu-lar itching from allergic conjuncti-vitis (p<0.0001), it did not achieve

the secondary endpoint of relieving conjunctival redness. Still, the drug was qualifi ed as safe and well-toler-ated. Researchers have since revised the protocol for a second, Phase III multicenter, 1:1 randomized, dou-ble-masked, vehicle-controlled trial, where the sole primary endpoint will be a reduction in ocular itching by day seven following insertion.

POST-OP OCULAR PAINOcular Therapeutix received accep-tance for a New Drug Application (NDA) from the FDA for the treatment of ocular pain following ophthalmic surgery, based on data from a single Phase II and two Phase III clinical trials—the latter of which achieved the primary endpoint of reduction of ocular pain but not the second primary endpoint of absence of cells in the anterior chamber.

In the Phase II trial of 247 patients, researchers found statisti-cally signifi cant differences between the Dextenza-treated group and placebo for both pain and absence of cells in the anterior chamber (p<0.005). All patients retained the device through day 14, and 97% of patients retained it through day 30. No long-term intraocular pressure spikes were observed. Rescue med-

ications were required by a small-er number of Dextenza subjects (20.7% vs. 72.4%) compared with the number of placebo subjects at days 14 and 30; the Dextenza sub-jects also exhibited fewer adverse events (13.8% vs. 43.8%).

Unfortunately, the 240-patient Phase III trial failed to meet the primary endpoint for reduction

of ocular infl ammation (Dextenza 39.4% vs. placebo 31.3%). A third Phase III trial aimed at achieving the same primary endpoint recently began enrolling patients, and it is the company’s intention to fi le a supplement to the NDA if the study is successful.

The two prospective, multi-center, randomized parallel-arm, double-masked, vehicle-controlled Phase III trials were completed with a total of 487 patients undergoing unilateral clear corneal cataract surgery. Patients were randomized 2:1 to receive either Dextenza or a placebo vehicle punctal plug. As stated, the two primary effi cacy endpoints were absence of cells in the anterior chamber at day 14 and the absence of pain, subjectively re-ported on a scale of 0 to 10, at day eight. Secondary effi cacy endpoints were absence of fl are in the anterior

“AN INTRACANALICULAR DEPOT IS INSERTED INTO THE PUNCTA TO PROVIDE ONE-MONTH TAPERED RELEASE OF MEDICATION.”



chamber at each visit and absence of cells and absence of pain at each visit, other than the day used for the primary effi cacy measure.

The new Phase III trial expected to constitute the supplement to the NDA allows for modifi cations of the original protocol, including a 1:1 (rather than 2:1) randomiza-tion of patients; the exclusion of patients undergoing treatment with high doses of oral NSAIDs; and improved training and guidance for on-site clinical investigators regard-ing adherence to study protocols, including the appropriate use of rescue medications.

INFLAMMATORY DRY EYEAt the end of 2015, results from a Phase II exploratory clinical

trial for the treatment of signs and symptoms of moderate to severe dry eye disease were released. The prospective, randomized, par-allel-arm, double masked, vehi-cle-controlled study included 43 patients (86 eyes) at two sites in the United States. Patients were initially treated with a placebo punctal plug for 45 days; those patients who benefi ted were excluded from the subsequent treatment phase. Treated patients were randomized 1:1 to receive either Dextenza or a placebo vehicle for 30 days.

Total corneal staining at day 30 showed the Dextenza group had statistically signifi cant improvement at day 30 as compared to placebo (p=0.018). Subjectively, there was improvement as measured by the

standard patient evaluation of eye dryness (SPEED) questionnaire for dryness, itchiness and scratch-iness. There were no intraocular spikes noted, and there was a 96% retention rate of the drug depots throughout the 30-day trial.

While the results from these trials are mixed, it remains

clear that an alternative method of drug delivery can be effective for certain ocular conditions and symp-toms. Hopefully, this is the gateway to further research that will enable us to offer our patients a cost-ef-fective, safe and easy method to overcome some common ocular issues that are undermined not by pharmaceutical shortcomings but, rather, human ones. RCCL

THE GP EXPERTS: GOOD CHEMISTRY(Continued from page 39)

rubbing step for proper cleaning. Current peroxide-based solutions on the market include ClearCare Plus (Alcon), PeroxiClear (Bausch + Lomb), and OxySept UltraCare Formula (AMO).

MULTIPURPOSE SOLUTIONS For some patients, cleaning and disinfecting a GP lens with two separate solutions can be bur-densome or confusing. A multi-purpose solution (MPS) may be a more convenient and appropriate choice for these patients. Boston Simplus (Bausch + Lomb) con-tains the surfactant poloxamine 1107 and hydroxyalkylphospho-nate to remove protein deposits, clorhexidine gluconate and PAPB preservatives to disinfect the lens,

and glucam-20 and hydroxypro-pylmethylcellulose (HPMC) for cushioning and wetting. Product guidelines recommend that lenses be removed every night and di-rectly in solution; in the morning, the lens should be rubbed gently on either side for 20 to 30 seconds and rinsed prior to lens insertion.

Unique pH multipurpose solu-tion (Menicon) is the same formu-lation as the former Opti-Free GP (Alcon). Preserved with polyquad and EDTA, Unique pH also con-tains hydroxypropyl guar, polyeth-ylene glycol, tetronic 1304, boric acid and propylene glycol to aid in cushioning and wettability. The formula also allows the solution to adjust viscosity based on the pH of the ocular surface. While

no rinsing is typically required, if the SupraClens (Alcon) enzyme is added to the solution, the lens should be rinsed thoroughly prior to insertion.

With any lens/solution com-bination, practitioners

should inform patients regarding proper use and potential problems to watch for. Always be sure to remain up to date on the latest research to ensure your recom-mendations are the best option for your patients. RCCL

1. Cannella A. Polymer Chemistry. In: Bennett ES, Weissman BA, ed. Clinical Contact Lens Practice. 4th Ed. Philadelphia, PA: Lippincott, Williams & Wilkins; 2005: 235-242.2. Bennett ES, Wagner H. Gas-permeable lens care and patient education. In: Bennett ES, Henry VA, ed. Clinical Manual of Contact Lenses. 4th Ed. Philadelphia, PA: Lippincott, Williams & Wilkins; 2014: 157-186.


By Gary Gerber, OD

Out of the Box


What’s in a Name?Even the smallest changes in how your staff members present themselves to patients can have the biggest impact.

Recently, an intense discussion among our clients occurred about a seemingly benign subject—staff

uniforms. Specifi cally, name tags: where can they be bought, and should the practice logo be printed on them?

As I often do when things become nitty-gritty, I took a step back to examine the big picture of this particular practice-building topic. Why would a practitioner mandate (or not) that staff wear uniforms and if they do, why a particular type, style or color? What about the pros and cons of using name tags vs. writing the staff member’s name in embroidery? Why display any name at all? And what about complementary items like laboratory coats and/or ties?

There is, of course, no universal answer for these questions—it depends upon the practice’s model, mission statement, values, culture and long-term goals. It is more than likely, however, that every practice has one communal thread tying them all together: they are all attempting to connect and relate to patients, which benefi ts both the clinical care aspect and the business as a whole.

So, with respect to the staff dress code, is there anything that can be done to help connect with the patient? Can altering something so seemingly simple bring about such an important change as an increase in patient loyalty? Is there anything that can be done along these lines with respect to a staff

dress code? After a recent visit to a Westin Hotel, I believe the answer to this question is, in fact, yes.

NICE TO MEET YOU

Her name tag read: My name is Shannon. My passion is cooking. Though I’m not a foodie and I only have a limited interest in cooking, this simple line caught my attention. In effect, it brought to the forefront the woman’s individuality and gave me the feeling that if I had a problem during my stay, I could rely on her to help me resolve it more so than someone else. And if I didn’t have a problem, I would still have an “insider” at this particular hotel the next time I came.

During my short stay, I learned about other employees at the hotel with passions that varied from sports and travel to fi lm. I developed an underlying feeling that during staff meetings, the presentation likely began with the maintenance engineer taking about his weekend gardening project, rather than the upcoming elevator closure schedule, and I also thought that during a particular grinding and challenging work day, an employee touching base with a returning guest who recognized them and remembered the employee’s daughter’s soccer team, helped that employee get through the day a little easier.

See what that simple name tag did? I was already thinking about my next stay as if it was a given. In effect, that simple name tag

change led to a better connection between an employee and a guest, a better sense of teamwork among employees and a better overall mood in the work environment. These are the real reasons for the Westin’s name tag technique—reasons that can easily be applied in the context of an optometry practice.

So, the next time you have to make a business decision, no matter how seemingly small—what is smaller than a name tag, anyway?—make it in the context of looking at the bigger picture. Ask yourself, “Why am I doing this, what are its long-term benefi ts and how is it going to support my practice mission and values?”As is often the case, and as you saw with the name tags, these decisions are rarely obvious and take some creativity. If you’re a self-employed decision-maker reading this, don’t worry about the immediate repercussions. Adding a name tag is a simple and inexpensive change. Just go with it and see what happens.

And the next time you see me, my tag will say, “My name is Gary Gerber. My passion is helping optometrists succeed.” RCCL

ght change led to a better

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1Gabriel M, Bartell J, Walters R, et al. Biocidal efficacy of a new hydrogen peroxide contact lens care system against bacteria, fungi, and Acanthamoeba species. Optom Vis Sci. 2014; 91: E-abstract 145192. © 2015 Novartis 5/15 CCS15069AD-B

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