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Contents lists available at ScienceDirect

Contact Lens & Anterior Eye

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ase report

cleral lenses in the treatment of post-LASIK ectasia and superficialeovascularization of intrastromal corneal ring segments

lise G. Kramer ∗, Edward L. Boshnick1

lobal Vision Rehabilitation Center, 7800 SW 87th Ave, Miami, Ste B-270, Kendall, FL 33173, United States

r t i c l e i n f o

rticle history:eceived 23 November 2014ccepted 2 February 2015

eywords:ctasiaCRScleral lenseseovascularization

a b s t r a c t

Objective: This case report aims to explore the use of scleral lenses for the treatment of ocular and visualcomplications in an adult patient presenting with post-LASIK (Laser-Assisted in situ Keratomileusis)ectasia in both eyes with cross-linking in the right eye and intrastromal corneal ring segments (ICRS;Intacs, Addition Technology, Fremont, CA) in the left eye.Methods: Following a comprehensive eye exam and specific testing for contact lens fitting, scleral lenseswere fitted with success in both eyes and dispensed. Due to progressive fibrosis and neovascularization ofthe inferior ICRS in the left eye, the inferior ICRS was removed and scleral lenses were refit with success.Results: Prescribed scleral lenses helped the patient achieve optimal visual correction (20/20) as well asocular protection of the cornea.
Conclusion: Post-LASIK ectasia is a common finding among contact lens specialists today. When ICRSsurgery is involved, the fitting of contact lenses may become more challenging. Scleral lenses offer aunique way of addressing many issues raised in this case report including corneal neovascularization andectasia. This lens modality may be considered for any other case involving irregular corneal curvaturefollowing surgery resulting in reduced visual acuity.
© 2015 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

. Introduction

Post-LASIK ectasia is defined as refractive or optical regressionesulting from a bulging forward of the ablated cornea slightly toteepen both the anterior and posterior corneal curvature, after anneventful LASIK (Laser-Assisted in situ Keratomileusis) procedure1,2]. This bulging forward occurs similarly with corneal relax-tion incisions after radial keratotomy (RK) [2]. In RK, however, theeripheral cornea is weakened, leading to steepening of the periph-ral and flattening of the central cornea, whereas in myopic LASIK,he thinner and weaker central cornea results in central steepen-ng. Currently, this condition is challenging to manage for refractiveurgeons, and several therapeutic options have been proposed inecent studies [1]. These include RGP (rigid gas-permeable) contact

Please cite this article in press as: Kramer EG, Boshnick EL. Scleral lenscularization of intrastromal corneal ring segments. Contact Lens Ante

enses, corneal collagen crosslinking, topography-guided PRK (pho-orefractive keratectomy) with simultaneous crosslinking, cornealransplantation, and ICRS (intrastromal corneal ring segments).

∗ Corresponding author at: 19390 Collins Ave Apt 1222, Sunny Isles Beach, FL3160, United States. Tel.: +1 305 271 8206.

E-mail addresses: [email protected] (E.G. Kramer), [email protected]. Boshnick).

1 Tel.: +1 305 271 8206.

ttp://dx.doi.org/10.1016/j.clae.2015.02.003367-0484/© 2015 British Contact Lens Association. Published by Elsevier Ltd. All rights r

Evidence is meager regarding the best indication for each treatmentoption [1]. For reasons that are not apparent, the patient reportedin this case received two different treatments in each eye. The caseis relevant and particularly instructive, because despite differenttreatments in each eye and several modifications to the initial lensfitting, scleral lens therapy resulted in good acuity and comfortbilaterally. This report explores the challenges of fitting a sclerallens after different treatments in each eye and the troubleshootinginvolved in reaching a successful outcome in both. Of note, patientconsent was received for both use of images and publication of thecase.

2. Case report

In the summer of 2013, patient JV, a 38 year-old Hispanicmale, presented to the Global Vision Rehabilitation Center. He wasreferred by a cornea specialist for a contact lens evaluation for thetreatment of fluctuating and unstable vision in both eyes and diffi-culty driving at night owing to halos and starbursts around lights.A review of his ocular history revealed LASIK in both eyes in 2001,

es in the treatment of post-LASIK ectasia and superficial neovas-rior Eye (2015), http://dx.doi.org/10.1016/j.clae.2015.02.003

ICRS surgery 2 months prior in the left eye and a cross-linking pro-cedure in the right eye 4 weeks prior to this initial presentation.He was also wearing an amniotic membrane corneal bandage lens,PROKERA® (Bio-Tissue, Miami, USA), 3 weeks prior to presentation

eserved.

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mailto:[email protected]

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Fig. 1. ICRS with crystallized deposits around the ring segments. Superficial stromalvaa

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ascularization extending to and arborizing along the inferior ring segments at 4:00nd 6:00 can be seen. Mild underlying haze around the inferior ring segment canlso be observed.

or 4–5 days over his right eye following the cross-linking. He hado history of glaucoma or trauma and was not using any eye drops.e had no family history of ocular disease nor had he been diag-osed with any medical problems, was not taking any medicationsnd had no allergies to drugs.

Entering acuities measured 20/40 in the right eye and 20/30 inhe left eye with spectacle correction. His refraction measured OD:2.25 − 4.50 × 080 and OS: +2.75 −5.00 × 105. With this correction,is acuities were 20/30 and 20/25, respectively; yet he reportedignificant distortion of the letters. His pupils were equal, roundnd reactive to direct and consensual illumination, and no affer-nt pupillary defect in either eye was observed. Confrontationalisual fields were full to finger counting in both eyes and extraoc-lar motility was full in both eyes. Slit lamp examination revealed

ntacs segments in place 2 mm above and below the pupil in theeft eye, with crystallized deposits around the ring segments. Head superficial stromal vascularization extending to and arborizinglong the inferior ring segment at 4:00 and 6:00, with mild under-ying haze (Fig. 1). The patient had clean lids and lashes, white anduiet conjunctivas, flat irides and clear lenses OD, OS. No propto-is or lid abnormalities were observed in either eye. Intraocularressures by Goldmann applanation tonometry measured 13 mmg OU at 11:00 AM using one drop 0.5% proparacaine hydrochlo-

ide ophthalmic solution. Upon dilated fundus examination (usingne drop 1% tropicamide and 2.5% phenylephrine OU), the cup-to-isc ratios were 0.2 OD, OS. The neuroretinal rims were healthynd pink in both eyes. The maculae were clear and flat in both eyes,nd retinal vasculature was of normal course and caliber. No breaksere observed in the retinal periphery. A flat nevus was seen just

uperior to the arcade in the right eye, of approximately 2/3 of aisc diameter.

After the glasses were prescribed, contact lenses were stronglyecommended as the primary treatment for the ectactic corneasn both eyes with vascularized Intacs in the left eye. In this con-ition, the ocular surface must be protected to minimize the riskf erosion; contact lenses help to maintain constant lubrication ofhe corneal surface, which allows for its restoration. A soft ban-age does not provide a good outcome for visual correction on aighly irregular cornea. Small diameter rigid gas-permeable (RGP)

enses can provide a better alternative to improve visual acuity buto not protect the ocular surface. In fact, these lenses can increase


echanical stress on an already altered cornea in this case. One ofhe ways to resolve this issue could be to consider a piggy-backystem, which implies fitting a high oxygen permeability soft lensarrier on top of which a high-permeability RGP lens is fitted. In

PRESS& Anterior Eye xxx (2015) xxx–xxx

that way, the soft carrier aims to protect the cornea while the RGPrestores visual acuity. Another solution includes the implementa-tion of hybrid lenses. These consist of a gas-permeable rigid centersurrounded by a silicone hydrogel soft skirt. In fitting this lens, theskirt is designed to lift the rigid center off the corneal surface sothat it never has to interact with it. However, cases of warpagewith these lenses have been reported [3]. In addition, few, if any,hybrid lenses offer enough oxygen permeability to maintain ocularhealth in the presence of a compromised cornea [3].

Large-diameter RGP lenses can also be considered. Thesedesigns have become more and more popular and are availablein several options: a corneo-scleral lens (12.5–15 mm), supportedpartly by the cornea and partly by the sclera; a mini-scleral lens(15–18 mm) vaulting the cornea, supported by the fluid layer andthe conjunctiva; or a larger scleral lens (18–25 mm) with the samefitting philosophy as the mini-scleral lens but with different param-eters [4]. They are fitted in a way to vault the cornea. They maintaina constant reservoir of fluid between the posterior surface of thelens and the anterior surface of the cornea to ensure hydration[5]. This fluid layer also compensates for the surface irregular-ities, leading to improved visual acuity. In fact, correction ofirregular astigmatism was the primary indication for scleral lensesin early studies, but more recent studies have confirmed theirutility in the management of various ocular surface diseases includ-ing keratoconjunctivits sicca, neurotrophic keratopathy, cicatrizingconjunctivitis, limbal stem cell deficiency, and exposure keratopa-thy [4]. The unique way scleral lenses are fitted enable them toprotect the ocular surface from the friction generated by eyelidmovement and provide corneal hydration [5]. This modality canprovide the comfort of a soft lens with the optical quality of agas-permeable lens [4]. Large-diameter RGP lens designs currentlyavailable are therefore considered the best option to provide healthbenefits and increased comfort compared to smaller corneal RGPand, in this case, soft lenses.

In the current case of post-LASIK ectasia followed by cross-linking in one eye and ICRS in the other, the choice of which type oflarge-diameter RGP lens to use should ensure that no touch on thecornea occurs. Corneo-scleral lenses are contraindicated, because asmall portion of the cornea supports most of the weight of the lens.This may result in a stress to the tissue that could cause a cornealepithelial defect and/or generate scarring. Mini-scleral lenses rep-resent an improved option, where cornea–lens touch is absent butthe fluid layer limited. They are also smaller than the large sclerallenses and are therefore easier to handle and less intimidating forpatients to insert into their eyes [4].

The Jupiter scleral lens (Essilor Contact Lens, Dallas, TX) waschosen and the fitting was facilitated by the use of a diagnosticset of 14 lenses. The initial diagnostic lens was selected accord-ing to the manufacturer’s fitting guidelines. The base curve radiusof the diagnostic lenses ranged from 6.25 to 8.44 mm, the lenseswere 16.60 mm in diameter, and made of Boston XO material. Theclearance or fluid reservoir under the lens was evaluated with thehelp of the VisanteTM Anterior Segment OCT (Ocular CoherenceTomography) (Zeiss, Jena, Germany). When adequate apical clear-ance was confirmed (150–200 �m) in both eyes (Fig. 2), the lenseswere ordered with the following parameters:

OD: diameter: 16.60 mm, base curve 41.00 D (8.23 mm) reversecurve, power −0.75OS: diameter: 16.60 mm, base curve 39.00 D (8.65 mm) reversecurve, power +1.50.


Following appropriate training, the patient was proficient withboth insertion and removal of the lenses. He was instructedin lens care and handling with RGP cleaner and conditioning

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ig. 2. VisanteTM Anterior Segment images of the right (a) and left (b) eyes fitted aurface and back surface of the scleral lens. Note the Intacs represented by empty s

olution (BostonTM). Non-preserved 0.9% NaCl inhalation solutionas prescribed to fill the lens before insertion.

At the next visits, the patient reported pain after lens removal inhe left eye. Slit lamp and VisanteTM Anterior Segment OCT exam-nation both showed the inferior corneal ring segment pushingnteriorly at 6:00 against the scleral lens (Figs. 3 and 4), with posi-ive staining in this area of the cornea. Lens wear was discontinued,nd moxifloxacin ophthalmic solution was prescribed every hour.hen the patient returned the following day, he reported improve-ent but still had positive staining in the same area of the cornea.oxifloxacin ophthalmic solution was prescribed every 2 h in the

eft eye on the first day and every 4 h on the second day.At follow-up three days later, the staining had mostly resolved.

ecause the fibrovascular growth around the inferior corneal ringegment seemed to be progressing, however, the patient was


eferred for evaluation to a cornea specialist at the Bascom Palmerye Institute. The latter agreed with the prior assessment of fibrosisr infiltration of the inferior ring segment, with outward protrusionn addition to neovascularization in the lower half of the cornea.

ig. 3. VisanteTM Anterior Segment OCT enhanced high-resolution imaging of theeft eye, showing outward growth of the cornea around the inferior ICRS towardhe back surface of the lens, with minimal clearance in that area. Note the adequatelearance in the rest of the cornea.

tely with a scleral lens. Note 150–200 �m of apical clearance between the cornealin the left eye using enhanced high-resolution imaging.

The specialist discussed with the patient the recurrent inflamma-tion and potential infection due to the Intacs and planned to removethe inferior ICRS. Antibiotics were continued and cultures obtainedfor the left eye.

Two months later, the inferior corneal ring was explanted. Cul-tures and pathology were negative, and the patient was prescribedPredForte 6 times a day and Vigamox 4 times a day. The steroiddrops were progressively tapered. At the final follow-up with thesurgeon, the latter reported that the cornea had healed nicely in thearea of explantation, with no staining. The antibiotic drops werediscontinued, and PreForte was maintained at 4 times a day for 1month and then slowly tapered thereafter.

The patient was then referred back to the Global Vision Reha-bilitation Center for a new contact lens fitting. A new scleral lenswas fit on the left eye, for which a base curve of 8.39 mm, plano


power, and a diameter of 20.60 mm to completely vault over thecornea, the limbus and perilimbal bulbar conjunctiva were chosen.When the lens was dispensed, the superior corneal ring segmentwas touching the back of the lens, so it was steepened by 60 �m.

Fig. 4. VisanteTM Anterior Segment OCT enhanced high-resolution imaging of theleft eye, showing outward growth of the cornea around the inferior ICRS towardthe back surface of the lens, with minimal clearance in that area. Note the adequateclearance in the rest of the cornea.

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Fig. 5. VisanteTM Anterior Segment OCT enhanced high-resolution imaging of theleft eye showing 150–200 �m of apical clearance. Note the absence of inferior ICRand mild hyperreflectivity indicating scarring in the area of explantation.

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reported here, preoperative cultures and pathology of the cornealepithelium, as well as post-operative cultures and pathology of the

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The patient now wears a 20.60 mm diameter lens with a baseurve of 8.23 mm, in reverse geometry and a power of −1.50. Theision continues to be 20/20 in both eyes with no distortion. Api-al clearance and comfort are adequate in both eyes (Fig. 5); theens therefore provides an adequate vault over the surface and hasucceeded in maintaining corneal integrity. Although the patientontinues to have neovascularization on the inferior portion of the


ornea in the left eye, the insult has been removed; and furthermprovement is expected.

ig. 6. Atlas corneal topography of the right and left eyes. With above axial curvatures, nistorted placido discs in both eyes.


3. Additional tests/referrals

See Fig. 6.

4. Differential diagnosis

4.1. Ring segment extrusion

The most common cause of ICRS explantation (48.2%), accord-ing to Ferrer et al. [6]. It is caused by the superficial part of thecorneal stroma thinning over time, causing the ring segment to pro-trude forward and consequent epithelial breakdown. The latter is arequired finding for diagnosing ring segment extrusion [6]. In mostcases, extrusion is accompanied by melting; vascularization alsooccurs in some cases [6]. Our patient had corneal staining, indicat-ing an epithelial break. However, the cause of the irritation was notstromal thinning but forward protrusion of the superficial corneaand rubbing on the scleral lens. This was evident when the sclerallens was discontinued and steepened at a later visit; the patientthen experienced almost complete resolution of the corneal stain-ing. If the epithelial break had been caused by insufficient stromalintegrity, the epithelium would not have healed by discontinuingcontact lens wear or improving the fit. A scleral lens was deemednecessary for adequate vision. Because superficial neovasculariza-tion and fibrosis of the ICRS prevented an adequate fit of the sclerallens the patient was referred for an explantation evaluation.

4.2. Infectious keratitis

This is one of the four leading causes of ICRS explantation [6]. Tomake a definitive diagnosis, cultures must be positive [6]. In the case


Intacs, were both negative, thus excluding microbial keratitis as apotential diagnosis.

ote significant irregular astigmatism in both eyes. With below rings images, note

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.3. Mild channel deposits around the ICRS

Channel deposits of cells and protein are usually found on theroximal end of the ring segment near the incision [6]. Ruckhofert al. suggest that the deposits are caused by the physical separationf stromal lamellae when they are opened to create a channel formplantation of ICRS [7]. They also report that the incidence andensity of deposits increase with segment thickness and durationf implantation. Although they report an incidence as high as 60%7], no deposits could be seen on clinical examination or using theisanteTM Anterior Segment OCT in the patient described here.

.4. Segment migration

This post-operative complication causes undesirable refractiveutcomes [8]. The patient had no refractive complaints, and visionas stable with the help of scleral lenses. Segment migration hasot been shown to cause discomfort such as that experienced byhis patient [8]. In addition, his topography was stable from theime we first saw him until his referral back to the surgeon, furtheronfirming the stability of the segment’s position.

.5. Corneal melting

This is one of the four leading causes of ICRS explantation [6].iven the fact that the patient’s corneal staining was completely

esolved following discontinuation of the scleral lens, corneal melt-ng could not be the causative factor here. The insult was theuperficial cornea protruding forward and rubbing on the scleralens. This was evident when the scleral lens was discontinued at oneisit and steepened at a later visit; the patient experienced almostomplete resolution of the corneal staining. If the epithelial breakad been caused by a lack of corneal integrity, the epithelium wouldot have healed after discontinuing contact lens wear or improvinghe fit. In cases of corneal melting, the epithelium begins to break-own, followed by stromal loss [6]. The patient reported here hado stromal loss, as confirmed by the VisanteTM Anterior SegmentCT and slit lamp examination. A scleral lens was deemed neces-

ary to provide adequate vision. Secondary to neovascularizationnd fibrosis of the ICRS, an adequate fit could not be obtained with

scleral lens and the patient was referred for possible explantation.

. Discussion

The patient reported here had superficial corneal neovascu-arization after implantation with ICRS. ICRS is touted to be a

inimally invasive and reversible refractive treatment for theanagement of low to moderate myopia, keratoconus and post-

ASIK ectasia [6,9,10]. It was intended to achieve a clear centralptical zone, to preserve corneal tissue and defer corneal trans-lant surgery [11]. The rings are made of polymethylmethacrylatePMMA) in circumferencial sections and are inserted in a semicircu-ar channel between the lamellae of the stroma. The 3 main ICRS onhe market are Intacs (Addition Technology, Inc.), Ferrara (Ferraraphthalmics Ltd.), and Keraring (Mediphacos Ltd.) [6]. The changes

nduced in corneal curvature can be predicted using Barraquer’saw; when a material is added to the periphery of the cornea, aattening effect is achieved [12]. ICRS improves distance visual acu-

ty, cylinder, and coma-like aberrations in post-LASIK ectasia [13],ut the indications for ICRS implantation for this condition remainnclear [13]. In a case series reported by Brenner et al., the bestandidates for ICRS in patients with post-LASIK ectasia were those


ho lost two or more lines of best-corrected visual acuity becausef ectasia and patients with grade 4 post-LASIK ectasia, defined asevere visual debilitation and a best-corrected visual acuity lesshan 20/40 [1]. These patient showed a mean improvement of 2.89

PRESS& Anterior Eye xxx (2015) xxx–xxx 5

lines of visual acuity 12 months after ICRS implantation. Those whohad grades 2 and 3 ectasia actually gained little acuity, however, andthose who had grade 1 ectasia experience loss of visual acuity afterimplantation [1].

Intrastromal corneal ring segment implantation has been asso-ciated with intraoperative and postoperative complications [6].Intraoperative complications include segment decentration [14],ICRS asymmetry [14], inadequate channel depth [14], superficialchannel dissection with anterior Bowman layer perforation [6], andanterior chamber perforation [6]. Although ICRS is usually welltolerated, some in vitro studies found activation of keratocytes,accumulation of lipids in cells and new collagen formation afterimplantation [15]. Several postoperative complications have beendescribed, including ring segment extrusion [6,14], corneal neo-vascularization [6,9,14], infectious keratitis [6,14], mild channeldeposits around the ICRS [6], segment migration [6,14], and cornealmelting [6]. In the U.S. Food and Drug Administration phases IIand III clinical trials of Intacs, segment removal was necessaryin 4.68% of eyes [11]. The authors of the latter study concludedthat intrastromal ring segments were safely, effectively and easilyremoved, with a return to preoperative refractive status within 3months [11].

Corneal neovascularization after Intacs has been infrequentlyreported [9,16]; it is usually superficial and localized to the site ofthe surgical wound [9]. In a study of 33 eyes with keratoconus afterIntac surgery, Siganos and associates found superficial, mild vascu-larization at the wound site in 1 eye after 2 months [17]. Kymionisand colleagues described similar findings in 2 of 10 eyes treatedwith Intacs for post-LASIK ectasia [18]. Both Al-Torbak et al andCosar et al reported cases of deeper vascularization 7 months and3 years after surgery, respectively [9,16]. Cosar et al. speculate thathypoxia of the cornea superficial to the Intacs may be the trigger-ing factor for neovascularization, as no inflammation was foundon clinical examination [16]. Both Al-Torbaket al and Cosar et al.report disappearance of the vessels after explantation of the Intacsand anti-inflammatory therapy, suggesting that the Intacs incitedthe neovascularization [9,16].

It is safe to assume that neovascularization will continue toprogress if the causative factor is not removed. Although a sclerallens may provide visual correction of a post-LASIK ectasia corneawith ICRS, neovascularization and fibrovascular growth progres-sion may prevent an adequate fit, and ICRS explantation may benecessary. Achieving adequate visual acuity may require post-surgical refitting. Scleral lenses of various designs have been usedin the management of several ocular surface diseases [4]. TheJupiter scleral lens was used in this study; it is likely that othercommercially available scleral lens designs with similar fittingcharacteristics would have also been successful in the managementof this condition. Scleral lens fitting with a standard set of diagnosticlenses can be accomplished efficiently. Although minor alterationswere required to optimize vision and fit, the fitting process wassuccessfully completed when appropriate fit and expected visualacuity were observed and when the patient reported comfortablewear for at least 8 h a day.

6. Conclusion

In the patient reported here, scleral lens fitting failed to achieveadequate visual acuity in the left eye until the ICRS was removed.The patient’s inferior ICRS caused hypoxia in the lower cornea,


inducing superficial neovascularization and outward fibrovascularproliferation, causing corneal epithelial breakdown and moderateto severe discomfort with continued scleral lens use. Followinginferior ICRS explantation, a scleral lens was successfully fit. The

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eovascularization is expected to regress further because the insultas been removed.

Although fitting a scleral lens on an eye with ICRS complica-ions remained challenging following appropriate evaluation andreatment by a cornea specialist, adequate vision and comfort werechieved and the patient’s chief complaint was resolved.

With the increasing recent interest of clinicians and manu-acturers, scleral lenses are becoming far more “mainstream” inontact lens practice. Optometrists should continuously updateheir expertise in the area of contact lens design, thereby provid-ng their patients with the latest lens technology and to optimizereatment.

eferences

[1] Brenner LF, Alió JL, Vega-Estrada A, Baviera J, Beltrán J, Cobo-Soriano R. Indi-cations for intrastromal corneal ring segments in ectasia after laser in situkeratomileusis. J Cataract Refract Surg 2012;38:2117–24.

[2] Naroo SA, Charman WN. Changes in posterior corneal curvature after photore-fractive keratectomy. J Cataract Refract Surg 2000;26(6):872–8.

[3] Gardner D, Zimmerman A. Myopic shift secondary to hybrid lens wear. ContactLens Spectr 2012;27(June):44–8.

[4] Van der Worp EA. Guide to scleral lens fitting. [Forest Grove, Ore.]. College ofOptometry, Pacific University; 2010. p. 1–4.


[5] Schornack MM, Pyle J, Patel SV. Scleral lenses in the management of ocularsurface disease. Ophthalmology 2014;121(July (7)):1398–405.

[6] Ferrer C, Alió JL, Montanés AU, Pérez-Santonja JJ, del Rio MA, de Toledo JA, et al.Causes of intrastromal corneal ring segment explantation: clinicopathologiccorrelation analysis. J Cataract Refract Surg 2010;36(June (6)):970–7.

[

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[7] Ruckhofer J, Twa MD, Schanzlin DJ. Clinical characteristics of lamellar channeldeposits after implantation of Intacs. J Cataract Refract Surg 2000;26:1473–9.

[8] Yeung SN, Lichtinger A, Ku JY, Kim P, Low SA, Rootman DS. Intracornealring segment explantation after intracorneal ring segment implantation com-bined with same-day corneal collagen crosslinking in keratoconus. Cornea2013;32(December (12)):1617–20.

[9] Al-Torbak A, Al-Amri A, Wagoner MD. Deep corneal neovascularization afterimplantation with intrastromal corneal ring segments. Am J Ophthalmol2005;140:926–7.

10] Torquetti L, Ferrara G, Almeida F, Cunha L, Ferrara P, Merayo-Lloves J. Clinicaloutcomes after intrastromal corneal ring segments reoperation in keratoconuspatients. Int J Ophthalmol 2013;6(6):796–800.

11] Boxer Wachler BS, Christie JP, Chandra NS, Chou B, Korn T, Nepomuceno R.Intacs for keratoconus. Ophthalmology 2003;110(May (5)):1031–40.

12] Rho CR, Na KS, Yoo YS, Pandey C, Park CW, Joo CK. Changes in anterior andposterior corneal parameters in patients with keratoconus after intrastromalcorneal-ring segment implantation. Curr Eye Res 2013;38(August (8)):843–50.

13] Park J, Gritz DC. Evolution in the use of intrastromal corneal ring segments forcorneal ectasia. Curr Opin Ophthalmol 2013;24(July (4)):296–301.

14] Miranda D, Sartori M, Francesconi C, Allemann N, Ferrara P, Campos M. Fer-rara intrastromal corneal ring segments for severe keratoconus. J Refract Surg2003;19:645–53.

15] Twa MD, Ruckhofer J, Kash RL, Costello M, Schanzlin DJ. Histologic evaluation ofcorneal stroma in rabbits after intrastromal corneal ring implantation. Cornea2003;22:146–52.

16] Cosar CB, Sridhar MS, Sener B. Late onset of deep corneal vascularization: arare complication of intrastromal corneal ring segments for keratoconus. Eur JOphthalmol 2009;19(March–April (2)):298–300.


17] Siganos CS, Kymionis GD, Kartakis N, Theodorakis MA, Astyrakakis N, PallikarisIG. Management of keratoconus with Intacs. Am J Ophthalmol 2003;135:64–70.

18] Kymionis GD, Siganos CS, Kounis G, Astyrakakis N, Kalyvianaki MI, Pallikaris IG.Management of post-LASIK corneal ectasia with Intacs inserts. Arch Ophthal-mol 2003;121:322–6.

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scleral lenses in the treatment of post lasik ectasia and superficial neovascularization of intrastr

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