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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”
• Overall/opticalzonediameter• Lens‐to‐corneafittingrelationship• Blend• Edgeclearance• Centerthickness• Edgedesign
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• Canbelight,mediumorheavy• GPlensesshouldbeblended(mediumtoheavypreferred)
– Preventpossiblesharpjunctionproblems
– Provideeventearflow/debrisremoval
– Minimizeadhesion
• Overall/opticalzonediameter• Lens‐to‐corneafittingrelationship• Blend• Edgeclearance• Centerthickness• Edgedesign
• Excessiveedgelift/clearanceactsinafunnel‐likemanner,dryingoutthesurroundingtearpool
• “Lidgap”mayfurtherexaggerateprocess
• Edgelift/clearanceisdecreasedby– Steepeningperipheralcurveradii– Decreasingperipheralcurve(bevel)width– Increasingnumberofcurves(widthunchanged)
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• Betterpressuredistributionwithuniformedgeclearance
• Improvedlens‐to‐corneafittingrelationship
• Comfort
• Overall/opticalzonediameter• Lens‐to‐corneafittingrelationship• Blend• Edgeclearance• Centerthickness• Edgedesign
• OneofthemostimportantimprovementsinGPlensmanufacturingtechnologyistheabilitytomakeultrathindesigns
• Recommendforallpatientswith≤1.50Dcornealcylinder
• Everylaboratoryhasseveralultrathindesigns• Significantlyreducelensmassandimprovethefittingrelationship
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• Overall/opticalzonediameter• Lens‐to‐corneafittingrelationship• Blend• Edgeclearance• Centerthickness• Edgedesign
• 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