Precision1® Contact Lenses With Smartsurface® Technology: Material

Properties, Surface Wettability and Clinical Performance

White Paper

Jessica Mathew, OD, PhD, FAAOAlcon Medical Affairs, Fort Worth, TX

Key Takeaways• Awettablecontactlenssurfaceiscriticalformaintainingasmoothandstabletearfilm.

• PRECISION1®(verofilconA)contactlenseshaveahighlybreathablesiliconehydrogelcorewith51%watercontentsurroundedbyapermanentmoisturelayerofhydrogelpolymerswith>80%watercontent.

• SMARTSURFACE®Technologyisamicro-thin(2-3microns)layerofmoisture,whichispermanentlyanchoredtothelenscorecreatingahighlywettableandlubricioussurface.

• PRECISION1®contactlensesshowedsuperiorinvitrolenssurfacewettabilityby1)maintaininganintactlayerofmoistureonthesurfacelongerand2)exhibitingaslowerrateofde-wettingwhencomparedto1-DayAcuvue^Moist,clariti^1DayandMyDay^contactlenses.

• PRECISION1®contactlensesachievedhighratingsfromwearersinoverallcomfort,overallvisionandoverallhandling.

New Contact Lens Wearer SatisfactionItiswellknownthatcontactlensdropoutisanissueforestablishedcontactlenswearers,1butarecentU.K.studyshowsthatdropoutisalsoaprobleminnewwearers(neophytes).2Thisstudyshowedthatnewwearersarenotcompletelysatisfiedwiththeirwearingexperience.Themainoverallissuesthatthenewwearersstruggledwitharepoorvision(41%),poorcomfort(36%)andhandling(25%).Whenthenewwearerswhohaddroppedoutofcontactlenswearwereasked“whatwouldpersuadeyoutotrycontactlensesagain?”,thetopthreeanswerswerebettervision,bettercomfortandeasierhandling.2

Optically Precise Tear Film Thetearfilm,whetheroverthecorneaoroveracontactlens,playsanimportantroleinbothcomfortandvision.3 Oureyesblinkapproximately14,000timesperday,meaningtheeyelidslidesoverthefrontofthecornea–oracontactlens–aboutonceeverysixseconds.4Additionally,thetearfilm,overlyingthecorneaoracontactlens,isresponsibleforapproximately70%oftheeyesrefractivepowercontributingtovision.5,6Therefore,establishingatearfilmthatisopticallyprecise(smoothandstable)atthecontactlenssurfaceiscritical.Awettableandlubriciouscontactlenssurfaceiskeyinachievingthisandultimatelysupports1)visualquality7and2)comfortbyreducingfrictionwiththeeyelid.3,8,9

Evolution of Water Surface TechnologyIn2013,Alconintroducedthefirstsoftcontactlenswithwatersurfacetechnology–DAILIESTOTAL1® water gradient contactlenses(delefilconA).Theadvancedchemistryofthislenswas,andis,novelanddifferentthananyothersoftcontactlensonthemarket.Theultrasofthydrophilicwatersurfaceprovidesexceptionallubricity,10 comfort8,9 and visualquality.11However,watergradienttechnologyisexclusivetothedelefilconAmaterialandrequirestheuseofLightStream®Technologyonthemanufacturingplatformforproductionof theselenses.

Alconhasdevelopedanewdailydisposablelensmaterialwithwatersurfacebenefits.Inordertodothis,novelsurfacechemistrywasutilizedalongwithauniquemanufacturingplatformoptimizedtointegratewatertothesurfaceofanewcoresiliconehydrogelmaterial.PRECISION1®(verofilconA)dailydisposablecontactlenseswithSMARTSURFACE®TechnologyarebuiltonthelegacyofwatersurfaceinnovationincombinationwithAlcon’slatestAgilientmanufacturingplatform.

PRECISION1® contact lenses with SMARTSURFACE® TechnologyVerofilconAisahighlybreathable(Dk/t@-3.00=100)siliconehydrogelmaterialwith51percentwatercontentatthe core of PRECISION1®contactlenses.TheSMARTSURFACE®Technologyisapermanentlayerofmoistureatthelenssurfacewith>80percentwatercontentandconsistsofboundhydrogelpolymersthatcompletelyencapsulatethecoreofthelens(Figure1&2).12Thelenscorehasamodulusof0.6MPaallowingforeasyhandlingandanultrasoftlenssurfacethatisseveralhundredtimessofterthanthecoretosupporton-eyecomfort(Figure2).12,13 Whilethesiliconehydrogelcoreallowsforhighoxygenpermeabilityandeasyhandling,theSMARTSURFACE® water layerhelpstosupportlenssurfacewettability,comfortandanopticallyprecisetearfilmforvisualquality.12,13

Figure 1: PRECISION1® Contact Lens Core and Surface Water Content

Material verofilconA

Type SiliconHydrogel

Group (per ISO 18369-1:2017) 5B(>50%water,nonionicatpH6-8)

Water content (core) 51%

Water content (surface) >80%

O2 Permeability (dK/t @ -3.00; CT 0.09) 100

Base curve (mm) 8.3

Diameter (mm) 14.2

Modulus (core) 0.6MPa

UV absorption ClassIUVblocker(≥90%UVA,≥99%UVB)

Surface technology SMARTSURFACE®

Handling tint VISITINT®

Powers -0.50Dto-6.00D(0.25Dsteps);-6.50Dto-12.00D(0.50Dsteps)+0.50Dto+6.00D(0.25Dsteps);+6.50Dto+8.00D(0.50Dsteps)

To create the SMARTSURFACE®waterlayeronPRECISION1®contactlenses,auniquemanufacturingprocesswascreatedfortheverofilconAmaterial.Thelensesgothroughaseriesofextractionsteps,whichincludeasequenceofdifferentbathsthatcontainahydrogelpolymer,polyacrylicacid(PAA).PAAisaveryhydrophilic(water-loving)polymerandisamaincontributortothehighwatercontent(>80%)onthelenssurface.Onebathoftheseriesslightlyexpandsthelensmaterial,temporarilyopeningsmallporesinthelenssurfacetoallowthePAAtopenetrateintothelenssurface.ThePAApolymersarelockedintoplacewhenthelensismovedtoasubsequentbathinthemanufacturingprocess.Finally,whenthelensisintheblisterpack,theheatfromtheautoclavestagecompletestheformationofthewatersurfacebycrosslinkingthePAAwithwettingagentsconsistingofcopolymersofpolyamidoamine(PAE)andpolyacrylamide-acrylicacid(PAAm-PAA).Thefinalresultisamicro-thinlayerofmoisture(2-3microns),whichispermanentlyanchoredtothelenscreatingahighlywettableandlubricioussurface(Figure3).12

Figure 2: PRECISION1® Contact Lens Parameters

Contact Lens Core WaterLayer

Anchor Zone

Figure 3: PRECISION1® Contact Lens with SMARTSURFACE® Technology Permanent,micro-thinwaterlayer(2-3microns)

Agilient Manufacturing Platform TheAgilientmanufacturingplatformwascreatedfortheproductionofPRECISION1®contactlenses,andwhileitisoptimizedfortheselenses,itisaversatileplatformthatcanbeusedforotherlensmaterialsinthefuture.Ingeneral,themanufacturingprocessincludesthesamebasicstepsasanyotherplatform,howeverthisnewsystemisfullyautomated,includespreciseinjectionmolding,andallowsfor100percenthighspeedcomputer-aidedvisualinspection.Mostimportantly,thissystemismodularandeasilyinterchangeable,makingitextremelyflexiblefortheproductionoffuturelensmaterials.

TheothermainbenefitisthattheAgilientmanufacturingprocessusesthermalcuringforPRECISION1®lenses,whichallowsfortheincorporationofUVabsorbingagentsintothelensmaterialprovidingClassIUVblockingprotection(≥90%ofUVA,≥99%ofUVB).

In Vitro Surface Wettability Contactlenswettabilitywasmeasuredin vitrousingtheiDDropmethodtoassessbothinitialwaterbreak-uptime(WBUT)andrateofwaterbreak-up(retentiontime)forPRECISION1®,DAILIESTOTAL1®,1-DayAcuvue^Moist,clariti^1DayandMyDay^lenses.14 This in vitromethodisusedtoshowsurfacewettingpropertiesofeachlensmaterialandisnotaclinicalperformanceassessment.Withthismethod,lenseswererinsed,thensoakedinphosphatebufferedsaline(PBS)for16hours+/-2hourstoremoveanyblisterpacksolution.ThelenseswerethenmountedonacurvedsurfacethatmaintainedtheshapeofthecontactlensandthensubmergedintoaPBSbath.ThelenseswerethenraisedabovethePBSsurfacewhileavideorecordingwastakenofthesurfaceofthelensesinordertovisualizethedynamicwaterbreak-upatthelenssurface.Thefirstinstanceofabreakinthelenssurfacemoistureisreportedasthesurfacemoisturebreak-uptime.Theretentiontimeanddewettingrateprofilesrepresenttherateatwhichthemoisturebreak-upspreadsacrossthelenssurface.Retentiontimewasreportedasthetimeittookforthesurfacemoisturecoveragetogofrom100%wettedto90%wetted.Thedewettingrateprofilesshowthetime

ittookforthesurfacemoisturecoveragetogofrom100%wettedto<10%wetted.Foreachlenstype,10lensesweretested,withthreemeasurementsperlensforatotalof30measurements.Betweenthe3lensmeasurementrecordings,thelenswasre-submergedinordertofullywetthelens.

PRECISION1®contactlensesdemonstratedsignificantlylongersurfacemoisturebreakuptimethan1-DayAcuvue^Moist,clariti^1DayandMyDay^lenses(p<0.001forall)(Figure4)meaningthatthesurfacemoistureremainedintact longer for PRECISION1®.14 PRECISION1®contactlensesalsoshowedsignificantlyhighermoistureretentiontimes(p<0.001forall)(Figure5a)anddemonstratedasignificantlyslowerrateofdewetting(p<0.001)(Figure5b)whencomparedto1-DayAcuvue^Moist,clariti^1DayandMyDay^lenses.14 This means that even after a breakinthemoistureoccurredonthelenssurface,themoisturelayerremainedinplacesignificantlylongerforPRECISION1®thanthecomparatorlenses.14

In this in vitrostudy,PRECISION1®contactlensesshowedsuperiorlenssurfacewettabilityby1)maintaininganintactlayerofmoistureonthesurfacelongerand2)exhibitingaslowerrateofdewettingwhencomparedto1-DayAcuvue^Moist,clariti^1DayandMyDay^lenses.1

Figure 4: Average surface moisture break-up time per lens brand. Surface moisture remained intact on the lens surface longer for PRECISION1®contactlensesasshownbyasignificantlylongersurfacemoisturebreak-uptimecomparedto1-DayAcuvue^Moist,clariti^1DayandMyDay^lenses(p<0.001).

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PRECISION1® 1-Day Acuvue^Moist

clariti^ 1 Day MyDay^

*p < 0.001

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Figure 5a: Average surface moisture retention timesdefinedastherateatwhichthemoisturebreak-upspreadacrossthelenssurfaceandshowsthetimeittookforthelenssurfacemoisturecoveragetogofrom100%wettedto90%wetted.PRECISION1®lensesmaintainedmoistureonthelenssurfacebetter,showingasignificantlylongermoistureretentiontimethan1-DayAcuvue^Moist,clariti^1DayandMyDay^lenses(p<0.001).

Figure 5b: Surface dewetting rate profilesdefinedastherateatwhichthemoisturebreak-upspreadacrossthelenssurfaceandshowsthetimeittookforthesurfacemoisturecoveragetogofrom100%wettedto<10%wetted.PRECISION1®lensesmaintainedmoistureonthelenssurfacebetterandshowedasignificantlyslowerdewettingratethan1-DayAcuvue^Moist,clariti^1DayandMyDay^lenses(p<0.001).

0

5

10

15

20

25

PRECISION1® 1-Day Acuvue^Moist

clariti^ 1 Day MyDay^

*p < 0.001

*21.3

0.9 0.8 0.7

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clariti^ 1 Day

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Clinical Study Results Inaprospective,randomized,double-masked,parallelgroupclinicalstudyof105subjects,lenseswerewornasdailydisposablesovera3-monthperiodandsubjectsratedtheiroverallcomfort,visionandhandlingona10-pointscale(1=worst;10=best)atmultipletimepoints.PRECISION1®one-daycontactlensesachievedhighratingsfromwearersinoverallcomfort(9.4,9.3,9.5),overallvision(9.4,9.3,9.4)andoverallhandling(9.0,9.1,9.2)at1,2and3months,respectively.Further,thesehighratingswereconsistentoverthe3monthsofwear(Figure6).15

Figure 6: Average subjective ratings over 3 months for comfort, vision and handling. PRECISION1®showedconsistentlyhighratingsforallmeasuresover3monthsofdailydisposablewear.

Conclusion PRECISION1®(verofilconA)dailydisposablecontactlensesareAlcon’slatestlensinnovationandfeatureauniquewatersurfacetechnologythatcreatesahighlywettableandlubriciouslenssurface.Asdemonstratedby in vitroandclinicalstudies,thesiliconehydrogelcoreprovideshighoxygenpermeabilityandeasyhandling,whilethe SMARTSURFACE®Technology,consistingofhydrogelpolymersand>80%water,providesasoftcushionofmoisturethatsupportsastabletearfilmand,ultimately,comfortandvision.14,15 PRECISION1® contact lenses with SMARTSURFACE®Technologyaredesignedtomeettheneedsofnewwearersandcanhelptokeepthemsatisfiedandsuccessfulwithcontactlenswear.

Disclosures:JessicaMathewisanAlconemployee.

See product instructions for complete wear, care and safety information.

^Trademarksarethepropertyoftheirrespectiveowners

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Overall Comfort Overall Vision Overall Handling

9.4 9.3 9.59.0 9.1 9.29.39.4 9.4

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