Download - The GP Lens Institute is the Optimizing Initial Comfort of GP Lenses ...€¦ · Len design and fitting relationship 1. Presentation ... Rigid Gas Permeable Contact Lenses” Edward

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EdBennett,OD,MSEd,FAAOUniversityofMissouri—St.Louis

CollegeofOptometryAssociateProfessor

Co‐Chief,ContactLensService

OptimizingInitialComfortofGPLenses

TheGPLensInstituteistheeducationaldivisionoftheContact

LensManufacturersAssociation

•  Gappractitioner•  Spectaclepromotion

•  Disposablelenses•  Awareness

•  Astigmatism•  Borderlinedryeyes•  Refits•  Irregularcorneas•  Presbyopia•  Children•  Orthokeratology/myopiacontrol

•  AstigmatismGPsprovideasmoothercornealcontourandbetterVA

•  BorderlineDryEyesMorewettablesurface;lessdryness‐inducedcomplications

•  RefitsSoftlensduetopoorvisionorcomplications

•  Irregularcornea/keratoconusSmoothesoutsomeofirregularityresultinginbetterVA

•  PresbyopiaImprovedmultifocaldesignsresultinvisionrivalingspectacles

•  ChildrenGPsprovidegoodvisionandmayslowdowntheprogressionofmyopia

•  OrthokeratologyGPsareabletoreduceexistinglowmyopia

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•  QualityofVision •  Resultofbetteropticalquality,surfacewettabilityandastigmaticcorrection

•  Johnson/Schniderstudy– 20patients– GPsfor6wksandsoftfor6wks– Allunadaptedwearersandgoodcandidates– VisionbetterandstaininglesswithGPs– 8preferredGPs– 15wouldbesatisfiedwearingthem

•  QualityofVision•  OcularHealth

•  Oxygentransmission2to4xgreaterthanhydrogellenses

•  Addedbenefitofgoodtearexchange(versussiliconehydrogel)

•  ReducedincidenceofGPC•  Reducedocularinfection(Stapleton,etal,2008)(www.contactlenssafety.org)

•  QualityofVision•  OcularHealth•  SurfaceWettability•  Durability/Stability

•  QualityofVision•  OcularHealth•  SurfaceWettability•  Durability/Stability•  ReductioninMyopiaProgression

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•  Studieswithyoungpeoplehavedemonstratedthatcornealreshapingcanresultinslowingaxiallengthgrowth– LORIC– CRAYON(Walline)

– ROK(Swarbrick)

•  QualityofVision•  OcularHealth•  SurfaceWettability•  Durability/Stability•  ReductioninMyopiaProgression

•  PatientRetention•  Profitability

•  GPsarecustomdevicesnotcommonlyavailablethroughtheinternet

•  Rarelyprice‐advertised•  Canuseserviceagreement

•  WithmandatorycontactlensRxrequirement,itislikelythatGPpatientsareevenmoreloyaltoday

•  AmesStudy– 38%ofpatientswerefitintoGPs– 48%ofprofitwasfromGPwearers

•  Ames/GunningStudy

– Profitperreplacementlenswashigher

– 2xasmanyspectaclesales

– 8xasmanyserviceagreements

1.  Presentation2.  Useofatopicalanesthetic3.  Vision4.  Materialselection

5.  Lendesignandfittingrelationship

1. Presentation

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Perceptionsaboutadaptation Concerns

•  Patientapprehension•  Practitionerapprehension

Thenewpractitioner

•Inadequateeducation•Takestoomuchtime•Toouncomfortable

•  Gaugepatient’sreactionstooculartests•  Highreactors=gradualadaptation•  Offerrealisticexpectations•  Don’tbetentativeinGPdescription•  Don’tusenegativephrases

– Discomfort,pain,intolerance,failure– Use“lensawareness,”“lidsensation”– “GP”(not“RGP”)

“TheEffectofPatientPersonalityProfileandVerbalPresentationonInitial

ComfortandAdaptationtoRigidGas

PermeableContactLenses”

EdwardS.Bennett

CristinaM.SchniderBruceW.Morgan

RuthDavies(etal)

•  49subjects,non‐CLwearers,ageandsexmatched,randomlyassignedto3groups

•Fear‐ArousingObservedavideoofdoctortalkingtopatientaboutGPadaptationusingfear‐arousingterms

•NeutralNon‐enthusedDoctortalkingtopatientusingneutraltermsbutisnon‐enthused

•NeutralEnthusedSameaspreviousbutdoctorhasapositiveattitude

•  Inthefirstmonth,6outof19droppedoutinthefear‐arousinggroup

•  2outof17droppedoutinneutralnon‐enthusedgroup

•  0outof13droppedoutintheneutralenthusedgroup

•  Fear‐arousinggroupsubmittedonly50%ofdailyquestionnaires

•  Theneutralnon‐enthusedgroupsubmitted55%

•  Theneutralenthusedgroupsubmitted87%ofthequestionnaires

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•  MethodofpresentationofGPlensescanaffectsuccess

•  Ifpresentednegatively,therewasasignificantlygreaterriskofdiscontinuationoflenswearduringthefirstmonthofwear

•  SubjectsprovidedwithapositiveapproachtowardGPsweremostlikelytobecompliantwithdailyquestionnairereturn

1.  Presentation2. Useofatopicalanesthetic

Itiscriticalforthepatient’sfirstexperiencetobeapositiveonewithGPlenses.Howthey

reacttothefirstfewminutesoflenswear

coulddeterminewhethertheywillbe

successful.

IfGPlensesareperceivedmorepositivelyby

patientsinitially,lessnegativecommentsand

fewerdropoutsshouldresult

•  Concerns– Staining– Effectofeyerubbing– Potentiallymisleadpatient

•  PotentialBenefits– Improvedinitialcomfort

– Lessreflextearing– Lessinitialchairtime

– Greaterpatientsatisfaction

“TheEffectofTopicalAnestheticUseonInitialPatientSatisfactionandOverall

SuccesswithRigidGasPermeable

ContactLenses”

EdwardS.BennettJenniferSmythe

VinitaAlleeHenry(etal)

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•  Onemonthstudy•  80subjectsatfourinstitutions(UMSL,SCO,PacificandOSU)

•  AllnewGPwearers•  Atfittingvisit

– 40givenophthaine– 40givenplacebo

•  Dropouts– 10total– 8intheplacebogroup

•  Patientsatisfaction– Perceptionofadaptationsignificantlybetterwithanesthetic

•  Itisimportanttoallowanesthetictowearoffsothepatientexperiencesrealisticawareness

•Topicalanestheticrecommendedfor–  AllnewGPpatients–  Children–  Keratoconics–  Softlensrefits–  AnyapprehensivepatientsRemember,youhavetocompetewithsoft

lensesinefficiencyandcomfort

1.  Presentation2.  Useofatopicalanesthetic3. Vision

•  Itisimportantforthepatient’sfirstexperiencetobeapositiveonevisually

•  Itislikelyiftheyachievegoodvisionwiththeinitiallenses,theywillbelesscognizantoflensawareness(i.e.,the“WOWFactor”)

•  Thiscanbeaccomplishedbyeitherempiricalorinventoryfitting

•  Veryeasyandsuccessfultodayduetoimprovementsinmanufacturingtechnology(i.e.,thindesigns,standardperipheries)

•  Typicallyproviderefractiveinformationtolaboratory(orusetheirnomogram)

•  Commonlyusedforsphericalandmultifocaldesigns

•  Hasbenefitsofgoodinitialvision,easeoffittingandpatientsatisfaction

•  Psychologicalbenefittopatient

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•  Needminimumof120to200lenses

•  Benefitsinclude– Goodinitialvision– Fitoutofstock– Lensreplacements– Parameterchanges

1.  Presentation2.  Useofatopicalanesthetic3.  Vision4. Materialselection

•  Fluorinecombinedwithotheringredientsofsiliconeacrylatetoenhancemucininteractionwithlenssurface

•  Increaseswettability,stabilityandDk•  MaterialscanbedividedbyDk

– LowDk=25to50(DWmyopes)– HighDk=51to99(hyperopes)– HyperDk=≥100(extendedwear)

Also:Greaterscratchresistance/HighRI

•MostmaterialscurrentlyhavetheirplasmatreatmentprocessFDAapproved

•  Itisnotacoating,butactuallyutilizeselectricalenergytochangetheelectricalstructureoflenssurface

•  VerypopularasthetreatingofGPpolymerswithplasmaisaveryeffectivecleaningmethodtoremoveanyremainingresidues(i.e.,oils,solvents,waxes)fromthemanufacturingprocess

•  Significantlyreducessurfacewettingangle•  Claimsthatitincreasesinitialcomfort

1.  Presentation2.  Useofatopicalanesthetic3.  Vision4.  Materialselection

5. Lensdesignandfittingrelationship

•  Overall/opticalzonediameter•  Lens‐to‐corneafittingrelationship•  Blend•  Edgeclearance•  Centerthickness•  Edgedesign

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•  Largerdiametersresultinbetterinitialcomfortwhetheritis10mm,intralimbal(11mmorlarger)orsemi/mini‐scleralduetolesslensmovementwiththeblinkandlesslidinteraction

•  Usesmalleroveralldiameterandsteeperbasecurveradiuswhenupperlidisatorabovethesuperiorlimbus(i.e.,interpalpebral)

•  Otherwisestriveforlidattachment

LargeDiameter(Scleral)GPSCLERALLENSCATEGORIES(SINDT,CLSOct.,

2008)(withDr.RobBreece)

•  Corneo‐Scleral:12.9‐13.5mm•  Semi‐Scleral:13.6‐14.9mm

•  Mini‐Scleral:15.0‐18.0mm

•  FullScleral:18.1‐24+mm

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SCLERALLENSGROWTH(GPAnnualReport2011:Oct.,2011CLS0

•  Thesalesoflargediameterbuttonshaveincreasedsixfoldfrom2006to2010

•  Thesaleshaveincreased14%in2011from2010

THEFUTURE:SCLERALLENSESFORHEALTHYEYES

•  JedlickaJ,ReederR,MalooleyM:October,2010ContactLensSpectrum(www.clspectrum.com....archive)

•  Futurecorneo‐scleralandsemi‐scleraldesignsmayrivalsofttoricsforastigmaticpatients

InitialComfort,Vision,andSubjectiveResponseofSemi‐Scleralvs.SoftToricvs.StandardGP

•  Comparisononasofttoric(ST)design,a14.3mmOADsemi‐scleral(SS)design,anda9.2mmOADstandardGP(SGP)

•  9subjectsevaluatedafter5,15&60minofwear(0–10scale):

•  Comfort(60Min):ST:9.3;SS:7.9;SGP:6.7•  Vision:SS:8.9;ST:8.9;SGP:6.9•  Adaptation:ST:9.4;SS:8.2;SGP:6.8•  Satisfaction:ST:9.1;SS:8.0;SGP:6.6

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•  Overall/opticalzonediameter

•  Lens‐to‐corneafittingrelationship•  Blend•  Edgeclearance•  Centerthickness•  Edgedesign

AlignmentPattern•  Light,evenpoolingoffluorescein

•  Slightlydenserperipheralpoolingduetoflatterperipheralcurveradius

•  Selectedtooptimizethelens‐to‐corneafittingrelationship

•  Oftenfittedclosetotheflatterkeratometryvalue(i.e.,“onK”)

CornealCylinder Fit0.00Dto0.50D 0.50Dto0.75Dflat

0.75Dto1.00D 0.25Dto0.50Dflat

1.25Dto1.50D “OnK”to0.25Dflat

1.75Dto2.00D 0.25Dsteep

2.25Dto2.50D 0.50Dsteep

*Fromthe“GPLIToricandSphericalLensCalculator”


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•  Canbelight,mediumorheavy•  GPlensesshouldbeblended(mediumtoheavypreferred)

– Preventpossiblesharpjunctionproblems

– Provideeventearflow/debrisremoval

– Minimizeadhesion


•  Excessiveedgelift/clearanceactsinafunnel‐likemanner,dryingoutthesurroundingtearpool

•  “Lidgap”mayfurtherexaggerateprocess

•  Edgelift/clearanceisdecreasedby– Steepeningperipheralcurveradii– Decreasingperipheralcurve(bevel)width–  Increasingnumberofcurves(widthunchanged)

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•  Betterpressuredistributionwithuniformedgeclearance

•  Improvedlens‐to‐corneafittingrelationship

•  Comfort


•  OneofthemostimportantimprovementsinGPlensmanufacturingtechnologyistheabilitytomakeultrathindesigns

•  Recommendforallpatientswith≤1.50Dcornealcylinder

•  Everylaboratoryhasseveralultrathindesigns•  Significantlyreducelensmassandimprovethefittingrelationship

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•  Resultsinamoreuniformedgethicknesssocentrationandcomfortcanbeimproved

•  Pluslenticulartothinahighminusedgeover≥‐5.00D

•  Minuslenticulartoincreaseedgethicknessforallplusandlow(≤‐1.50D)minuspowers

HighMinusLensWithoutLenticular

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•  Complications– Reduced/variablevisionandflare

– Limbalirritation/3&9staining

– Lensdislocation– Poorcornealalignmentresultinginexcessiveflatteningand/orsteepeningwithpossibilityofdistortion

– Lensawareness!

•  Management– Reducecenterthickness(ultrathin)

– Reduceedgeclearance– Properedgedesign

•  Minuslenticularlessthan‐1.50Dandallplus

•  Pluslenticulargreaterthan‐5.00D– Bitoricongreaterthan2.50Dcornealcylinder

– Lidattachmentdesign

Change•  OAD/OZDatleast0.3mm

•  Basecurveradiusatleast0.50D•  Centerthicknessatleast0.03mm

•  Peripheralcurveradiusatleast1.0mm

•  Peripheralcurvewidthatleast0.2mm

GPLI.infoPractitionerWebsite GPClinicalEducation

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PractitionerFittingAids

www.gpli.info

OnlineSymposia‐MonthlyWebinars

GPLensReference GPClick“n”Fit

PocketGuide ToricandSphericalCalculators

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GPLectureSeries

GPCaseGrandRoundsTroubleshootingGuide

•  Over70casesandtheirmanagementonwww.gpli.info

•  Casesarealluniqueandaredividedintothefollowingcategories:spherical(includingcomfort,dryness,desiccationanddecentration),toric,multifocal,keratoconus,post‐surgicalandcornealreshaping

•  Primaryandalternativemanagementoptionsareprovided

Thisresourceisanonlineguidethatapractitionercanaccess

whileintheexaminationroomto

helptroubleshootanyGPcase

DoctorandStaffResources•  Orderonline

–  Pocketguides–  Brochures

contactlenses.orgConsumerWebsite

•  Trainedconsultants– Assistwithmaterial,design,fittingandproblem‐solvingofbothsphericalandspecialtydesigns

•  Fittingsetsandinventories•  GPLIOn‐LineProductGuide

– www.gpli.infoformemberlaboratories– Lensdesigns/materialstheymanufacture

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•  GPsarethelensofchoicefor– Astigmaticpatients– Youngpeople– Presbyopes–  Irregularcorneas– Criticalvisionneeds

ComfortdoesNOThavetobeaproblem!GPLensescanBUILDyourpractice

Download - The GP Lens Institute is the Optimizing Initial Comfort of GP Lenses ...€¦ · Len design and fitting relationship 1. Presentation ... Rigid Gas Permeable Contact Lenses” Edward

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