Incidence of Epithelial Staining in Incidence of Epithelial Staining in Cornea & Conjunctiva of Successful Cornea & Conjunctiva of Successful

Soft Contact Lens WearersSoft Contact Lens WearersJan PG Bergmanson, OD, PhD, Jan PG Bergmanson, OD, PhD, …………

Texas Eye Research and Technology CenterTexas Eye Research and Technology CenterUniversity of Houston College of OptometryUniversity of Houston College of Optometry

Texas Eye Research and Texas Eye Research and Technology Center (TERTC)Technology Center (TERTC)

CoCo--workers:workers:RL Brautaset, RL Brautaset, KarolinskaKarolinskaInstitutetInstitutet, Stockholm, StockholmM M NilsonNilson KarolinskaKarolinskaInstitutetInstitutet, Stockholm, StockholmN Leach, N Leach, TERTCTERTCW Miller, W Miller, TERTCTERTCA Gire, A Gire, Baylor College of Baylor College of Medicine, HoustonMedicine, HoustonS Quintero, S Quintero, TERTCTERTC

Solution Interaction with the Ocular Surface: The Significance iSolution Interaction with the Ocular Surface: The Significance in Making the Graden Making the GradeChris Snyder, OD, MS, FAAO (Dipl.). Clinical & Refractive OptomeChris Snyder, OD, MS, FAAO (Dipl.). Clinical & Refractive Optometry 16:5, 2005try 16:5, 2005

The Pathogenesis of Contact LensThe Pathogenesis of Contact Lens--Related Related KeratitisKeratitis

ABSTRACTABSTRACTBacterial infection of the cornea is a rare, but sightBacterial infection of the cornea is a rare, but sight--threatening, complication of contact lens wear that was first rethreatening, complication of contact lens wear that was first reported shortly after soft lenses were introduced onto the ported shortly after soft lenses were introduced onto the market in the 1970s. During the past 3 decades, various attemptsmarket in the 1970s. During the past 3 decades, various attempts to solve the problem with new lens types and lens care productsto solve the problem with new lens types and lens care products have failed to make a significant impact have failed to make a significant impact on its incidence. Eliminating contact lenson its incidence. Eliminating contact lens--related infections will likely require a better understanding ofrelated infections will likely require a better understanding of the ocular defense system, microbial virulence strategies, how the ocular defense system, microbial virulence strategies, how they they affect one another, and the effects of contact lens wear on bothaffect one another, and the effects of contact lens wear on both. Each of these topics is complex. Although research in this are. Each of these topics is complex. Although research in this area is therefore challenging and necessitates a a is therefore challenging and necessitates a multidisciplinary approach, what we are learning along the way hmultidisciplinary approach, what we are learning along the way has significance beyond contact lensas significance beyond contact lens--related infection and could ultimately lead to the development orelated infection and could ultimately lead to the development of new f new strategies to prevent this and a range of other sightstrategies to prevent this and a range of other sight-- and lifeand life--threatening diseases.threatening diseases.

FLEISZIG, SUZANNE M. J. OD, PhD, FAAO. Optometry and Vision ScieFLEISZIG, SUZANNE M. J. OD, PhD, FAAO. Optometry and Vision Science, Vol.83(12), December 2006 ppE866nce, Vol.83(12), December 2006 ppE866--E873E873

Corneal Staining in Hydrogel Lens WearersCorneal Staining in Hydrogel Lens WearersAbstractAbstract

Purpose. The purpose of this study was to determine the factors Purpose. The purpose of this study was to determine the factors that contribute to corneal staining in hydrogel lens wearers by that contribute to corneal staining in hydrogel lens wearers by examining the examining the following variables: type of lens worn, wearing time and lens refollowing variables: type of lens worn, wearing time and lens replacement schedule, lens care system, and topical and systemic mplacement schedule, lens care system, and topical and systemic medication use.edication use.Methods. Five hundred fullMethods. Five hundred full--time, successful hydrogel contact lens wearers were evaluated fotime, successful hydrogel contact lens wearers were evaluated for corneal r corneal fluoresceinfluorescein staining at 20 clinical sites. staining at 20 clinical sites. Corneal staining was evaluated in five regions and was graded onCorneal staining was evaluated in five regions and was graded on a scale of 0 (no staining) to 4 (severe staining) in 0.5 steps a scale of 0 (no staining) to 4 (severe staining) in 0.5 steps for severity.for severity.Results. Corneal Results. Corneal fluoresceinfluorescein staining was present in at least one eye in 55.7% of the hydrogstaining was present in at least one eye in 55.7% of the hydrogel lens wearers examined in this study, and 8.0% had el lens wearers examined in this study, and 8.0% had moderatemoderate--toto--severe staining (defined as a cumulative staining score of >=3 wsevere staining (defined as a cumulative staining score of >=3 with at least one quadrant score >=2). Staining was most severe fith at least one quadrant score >=2). Staining was most severe for the or the inferior portion of the cornea (mean inferior portion of the cornea (mean ±± SD; OD: 0.34 SD; OD: 0.34 ±± 0.57, OS: 0.30 0.57, OS: 0.30 ±± 0.54). All other areas of the cornea showed lesser amounts of s0.54). All other areas of the cornea showed lesser amounts of staining, all of taining, all of which were approximately equal (mean range, 0.13 to 0.16). Stainwhich were approximately equal (mean range, 0.13 to 0.16). Staining was observed in two or more quadrants in 24% of right eyes aing was observed in two or more quadrants in 24% of right eyes and 22.4% of left nd 22.4% of left eyes. When questioned about care system compliance, 81.1% of subeyes. When questioned about care system compliance, 81.1% of subjects reported compliance. Patients who were noncompliant with tjects reported compliance. Patients who were noncompliant with their lens care heir lens care system ([chi]2 p = 0.0037), used rewetting drops ([chi]2 p = 0.0system ([chi]2 p = 0.0037), used rewetting drops ([chi]2 p = 0.0005), or wore conventional lenses without a planned replacement 005), or wore conventional lenses without a planned replacement schedule ([chi]2 p schedule ([chi]2 p = 0.0008) were more likely to have some degree of corneal staini= 0.0008) were more likely to have some degree of corneal staining. Noncompliance with care system ([chi]2 p = 0.0147), replacemng. Noncompliance with care system ([chi]2 p = 0.0147), replacement schedule ent schedule ([chi]2 p = 0.0039), and lens power ([chi]2 p = 0.0224) were ass([chi]2 p = 0.0039), and lens power ([chi]2 p = 0.0224) were associated with moderateociated with moderate--toto--severe staining. The following factors were not severe staining. The following factors were not significantly associated with corneal staining: patient age, gensignificantly associated with corneal staining: patient age, gender, medication use including oral contraceptives, type of wear der, medication use including oral contraceptives, type of wear (extended, flexible, or (extended, flexible, or daily), average wearing time, wearing time at the examination, ldaily), average wearing time, wearing time at the examination, lens type (spherical or ens type (spherical or torictoric), water content of lenses (high or low water content), ), water content of lenses (high or low water content), type of care system, use of enzymes, and pinching the contact letype of care system, use of enzymes, and pinching the contact lens directly off the cornea.ns directly off the cornea.Conclusions. Staining occurs to some extent in many hydrogel conConclusions. Staining occurs to some extent in many hydrogel contact lens patients, and is influenced by many factors. Moderatetact lens patients, and is influenced by many factors. Moderate--toto--severe severe staining, which may be more clinically significant, is associatestaining, which may be more clinically significant, is associated with noncompliance with care system, a conventional replacemend with noncompliance with care system, a conventional replacement schedule, and t schedule, and lens power.lens power.

NICHOLS, KELLY K. OD, MPH, PhD, FAAO; MITCHELL, G. LYNN MAS; STONICHOLS, KELLY K. OD, MPH, PhD, FAAO; MITCHELL, G. LYNN MAS; STONEBRAKER SIMON, KAREN M. OD; CHIVERS, DAWN A. NEBRAKER SIMON, KAREN M. OD; CHIVERS, DAWN A. OD; EDRINGTON, TIMOTHY B. OD, MS, FAAO. Optometry and Vision SciOD; EDRINGTON, TIMOTHY B. OD, MS, FAAO. Optometry and Vision Science, ence, VolVol 79(1), pp 2079(1), pp 20--30 30

Asymptomatic Corneal Staining Asymptomatic Corneal Staining Associated with the Use of Associated with the Use of BalafilconBalafilcon

SiliconeSilicone--Hydrogel Contact Lenses Hydrogel Contact Lenses Disinfected with a Disinfected with a PolyaminopropylPolyaminopropylBiguanideBiguanide--Preserved Care RegimenPreserved Care Regimen

ABSTRACT:ABSTRACT:Purpose. To compare subjective symptoms and signs in a group of Purpose. To compare subjective symptoms and signs in a group of individuals who wear siliconeindividuals who wear silicone--hydrogel lenses on a daily wear basis while they sequentially ushydrogel lenses on a daily wear basis while they sequentially used ed

two differing care regimens.two differing care regimens.Methods. Fifty adapted softMethods. Fifty adapted soft--lens wearers were fitted with a siliconelens wearers were fitted with a silicone--hydrogel lens material (hydrogel lens material (PureVisionPureVision, Bausch & Lomb). The lenses were worn on a daily wear basis , Bausch & Lomb). The lenses were worn on a daily wear basis

for two consecutive 1for two consecutive 1--month periods, during which the subjects used either a month periods, during which the subjects used either a PolyquadPolyquad (polyquaternium(polyquaternium--1) 1) --based system or a based system or a polyaminopropylpolyaminopropylbiguanidebiguanide (PHMB) (PHMB) --based system, using a doublebased system, using a double--masked, randomized, crossover experimental design.masked, randomized, crossover experimental design.

Results. Significant levels of relatively asymptomatic corneal sResults. Significant levels of relatively asymptomatic corneal staining were observed when subjects used the PHMBtaining were observed when subjects used the PHMB--based system, with 37% of subjects based system, with 37% of subjects demonstrating a level of staining consistent with a classical sodemonstrating a level of staining consistent with a classical solutionlution--based toxicity reaction. Only 2% of the subjects exhibited such based toxicity reaction. Only 2% of the subjects exhibited such staining when using staining when using the the PolyquadPolyquad--based system. These results were significantly different (p < 0.based system. These results were significantly different (p < 0.001). Significant symptoms were not correlated with the degree o001). Significant symptoms were not correlated with the degree of staining, f staining, with no differences in lens comfort or overall preference being with no differences in lens comfort or overall preference being reported between the regimens (p = NS). The only statistically sreported between the regimens (p = NS). The only statistically significant difference in ignificant difference in symptoms related to minor differences in stinging after lens inssymptoms related to minor differences in stinging after lens insertion being reported, with the ertion being reported, with the PolyquadPolyquad--based system demonstrating less stinging (p < based system demonstrating less stinging (p < 0.008).0.008).

Conclusions. Practitioners who fit siliconeConclusions. Practitioners who fit silicone--hydrogel contact lenses on a daily wear basis should be wary of hydrogel contact lenses on a daily wear basis should be wary of the potential for certain PHMBthe potential for certain PHMB--containing multipurpose containing multipurpose care systems to invoke corneal staining. Switching to noncare systems to invoke corneal staining. Switching to non--PHMB based regimens will eliminate this complication in most insPHMB based regimens will eliminate this complication in most instances.tances.

JONES, LYNDON PhD, FCOptom, FAAO; MACDOUGALL, NANCY JONES, LYNDON PhD, FCOptom, FAAO; MACDOUGALL, NANCY BScBSc, OD; SORBARA, L. GINA MSc, OD, FAAO. Optometry and Vision Scien, OD; SORBARA, L. GINA MSc, OD, FAAO. Optometry and Vision Science; ce; Volume 79(12),Volume 79(12), December 2002,December 2002, pp 753pp 753--761 761

Contact Lens Care Products Effect on Contact Lens Care Products Effect on Corneal Sensitivity and Patient ComfortCorneal Sensitivity and Patient Comfort

AbstractAbstractPurpose. To evaluate the possible effect of two leading soft conPurpose. To evaluate the possible effect of two leading soft contact lens care products on corneal sensitivity, relative comforttact lens care products on corneal sensitivity, relative comfort, and superficial corneal staining in adapted , and superficial corneal staining in adapted

disposable soft contact lens wearers.disposable soft contact lens wearers.

Methods. Eight disposable soft contact lens wearers equally diviMethods. Eight disposable soft contact lens wearers equally divided between habitual users of OPTIded between habitual users of OPTI--FREE Express Lasting Comfort No Rub formula (Alcon Laboratories,FREE Express Lasting Comfort No Rub formula (Alcon Laboratories, Fort Fort Worth, TX) and Worth, TX) and ReNuReNu MultiPlusMultiPlus (Bausch & Lomb, Rochester, NY) were enrolled in this crossover (Bausch & Lomb, Rochester, NY) were enrolled in this crossover study. The habitual lens care product was designated the first study. The habitual lens care product was designated the first crossover period. Patients completed a visual analog scale ratincrossover period. Patients completed a visual analog scale rating of midday and endg of midday and end--ofof--day comfort, underwent day comfort, underwent slitlampslitlamp examination for staining, and had corneal examination for staining, and had corneal sensitivity measured by sensitivity measured by CochetCochet--Bonnet Bonnet esthesiometryesthesiometry before and after being switched to the alternative lens care prbefore and after being switched to the alternative lens care product. The lens care product used was masked oduct. The lens care product used was masked from the investigator.from the investigator.

Results. Patients habitually using OPTIResults. Patients habitually using OPTI--FREE Express reported higher comfort ratings than did patients uFREE Express reported higher comfort ratings than did patients using sing ReNuReNu MultiPlusMultiPlus. On crossover, patients who initially used . On crossover, patients who initially used ReNuReNuMultiPlusMultiPlus experienced similar comfort when using OPTIexperienced similar comfort when using OPTI--FREE Express, but OPTIFREE Express, but OPTI--FREE Express users experienced a substantial decrease in comfortFREE Express users experienced a substantial decrease in comfort when when switched to switched to ReNuReNu MultiPlusMultiPlus. . EsthesiometryEsthesiometry showed significant differences in average sensitivity in favor showed significant differences in average sensitivity in favor of OPTIof OPTI--FREE Express (P=0.0041). Statistical trends FREE Express (P=0.0041). Statistical trends supported observed increases in corneal sensitivity when switchisupported observed increases in corneal sensitivity when switching to OPTIng to OPTI--FREE Express and decreased corneal sensitivity when switching toFREE Express and decreased corneal sensitivity when switching to ReNuReNu MultiPlusMultiPlus. . ReNuReNu MultiPlusMultiPlus was also associated with slightly more corneal staining.was also associated with slightly more corneal staining.

Conclusions. Conclusions. ReNuReNu MultiPlusMultiPlus, a , a biguanidebiguanide--based contact lens care product, was associated with decreased cbased contact lens care product, was associated with decreased comfort during midday and endomfort during midday and end--ofof--day periods. day periods. ReNuReNu MultiPlusMultiPlus was was also associated with significant reduction in relative corneal salso associated with significant reduction in relative corneal sensitivity compared to ensitivity compared to PolyquadPolyquad--based OPTIbased OPTI--FREE Express. Disturbance to normal corneal FREE Express. Disturbance to normal corneal sensitivity may play a role in contact lenssensitivity may play a role in contact lens--related dry eye and discomfort. Further investigation is warrantrelated dry eye and discomfort. Further investigation is warranted.ed.

Epstein, Arthur B. O.D., F.A.A.O. Eye & Contact Lens: Science & Epstein, Arthur B. O.D., F.A.A.O. Eye & Contact Lens: Science & Clinical Practice. 32(3):128Clinical Practice. 32(3):128--132, May 2006.132, May 2006.

Evaluation of Corneal Staining and Patient Preference With Use of Three Multi-Purpose Solutions and Two Brands of Soft Contact Lenses

AbstractEye & Contact Lens: Science & Clinical Practice. 29(4):213-220, October 2003.AbstractPurpose: Clinical signs and symptoms vary depending on contact lens brand, lens care products, or a combination of the two. Studies evaluated corneal staining and subject preference associated with three multipurpose solutions (MPS) and two soft contact lens brands.

Methods: Two sites conducted the randomized, investigator-masked, 2-month crossover studies. Forty-five subjects used regimen 1 (No Rub Opti-Free Express MPS [Alcon, Fort Worth, TX]) and regimen 2 (Complete MPS [Allergan, Irvine, CA]) for 1 month each (study 1). In study 2, 44 subjects used regimen 1 and regimen 3 (ReNu MultiPlus MPS [Bausch & Lomb, Rochester, NY]). ACUVUE 2 (Johnson & Johnson Vision Care, Jacksonville, FL) or SofLens 66 (Bausch & Lomb) lenses were randomly assigned to subjects for the duration of the study. Corneal staining was evaluated on days 0 (baseline), 7, 14, and 28 of each month.

Results: Corneal staining was significantly worse with regimen 3 for both lens brands at day 28 compared with baseline (P < 0.01). Significant differences in staining were noted between regimens 1 and 3 throughout the study, primarily with SofLens 66 lenses (P <= 0.0002). No consistent changes in staining were noted with regimens 1 and 2. Also, significantly more subjects preferred the comfort of regimen 1 (61.8%) to that of regimen 3 (11.8%). More subjects preferred the comfort of regimen 1 (57.1%) to that of regimen 3 (10.7%) compared with their prestudyregimen.

Conclusion: These studies showed that chemical variations between lens care systems and their interaction with contact lens materials create significant clinical, physiologic, and subjective preference differences.

Lebow, Kenneth A. OD, FAAO; Schachet, John L. OD

Interpretation of Corneal Staining on your Interpretation of Corneal Staining on your Patient and in the LiteraturePatient and in the Literature

Jan Bergmanson, OD, PhDJan Bergmanson, OD, PhDNordic Vision, 2006Nordic Vision, 2006

Range of Corneal StainingRange of Corneal Stainingin nonin non--CL wearers:CL wearers:

37 37 –– 79%79%

SchawallieSchawallie et al, 1997et al, 1997DundasDundas et al, 2001et al, 2001Norn, 1970Norn, 1970Korb and Korb, 1970Korb and Korb, 1970Korb and Herman, 1979Korb and Herman, 1979CaffreyCaffrey and Josephson, 1991and Josephson, 1991CeffreyCeffrey and Josephson, 1992and Josephson, 1992Thomas et al, 1997Thomas et al, 1997

Corneal and Conjunctival Epithelial Staining Corneal and Conjunctival Epithelial Staining in Hydrogel Contact Lens Wearersin Hydrogel Contact Lens Wearers

Brautaset RL, Nilsson M, Leach N, Miller W, Gire A, Quintero S, Brautaset RL, Nilsson M, Leach N, Miller W, Gire A, Quintero S, Bergmanson JPG Bergmanson JPG KarolinskaKarolinska Institute; TERTC Institute; TERTC

Accepted for publication in Accepted for publication in Eye and Contact LensEye and Contact Lens, 2008, 2008

records of 338 subjectsrecords of 338 subjectsrefractive errors (spherical equivalent) refractive errors (spherical equivalent) between 0.25 and between 0.25 and ––9.50 (median 9.50 (median ––3.50) 3.50)

Study DesignStudy Design

Conjunctival and corneal staining in adapted Conjunctival and corneal staining in adapted hydrogel contact lens wearers were evaluated hydrogel contact lens wearers were evaluated retrospectively.retrospectively.Records of subjects from silicone and hydrogel Records of subjects from silicone and hydrogel lens clinical trials conducted at the Texas Eye lens clinical trials conducted at the Texas Eye Research and Technology Centre (TERTC) over Research and Technology Centre (TERTC) over a 3 year perioda 3 year period

Study DesignStudy DesignStaining ProtocolStaining Protocol

Single instillationSingle instillation0.5mg large molecule 0.5mg large molecule NaFlNaFl stripstripUnpreserved physiological NaCl for wettingUnpreserved physiological NaCl for wettingImmediate observationImmediate observation

Study DesignStudy DesignObservationObservation

Cobalt light Cobalt light –– max light settingmax light settingWrattenWratten #12 (yellow) filter#12 (yellow) filterHaag Haag StreitStreit (BQ 900), halogen bulb(BQ 900), halogen bulb

13

4

2

5

3

2

4

1T N

Contact LensesContact Lenses

Wearing Schedule & SolutionsWearing Schedule & Solutions

Corneal Staining IncidenceCorneal Staining Incidence

NT3

5.9%

44.5%

25.6%

514.5%

14.2%

311.6%

224.3%

419.9%

127.9% NT

Conjunctival Staining IncidenceConjunctival Staining Incidence

TERTC Staining StudyTERTC Staining StudyIncidenceIncidence

Conjunctival staining in 32.5%Conjunctival staining in 32.5%Corneal Staining in 19.5%Corneal Staining in 19.5%None had staining above Grade 2None had staining above Grade 2

TERTC Staining Study TERTC Staining Study AssociationsAssociations

No association between staining and age, No association between staining and age, gender, refractive power, lens type, wearing gender, refractive power, lens type, wearing modality, or solution.modality, or solution.Corneal and conjunctival: staining unrelatedCorneal and conjunctival: staining unrelated

LakkisLakkis and Brennan (1996)and Brennan (1996) TERTCTERTCvsvs

Staining Study (2008) Staining Study (2008)

98% had staining regardless of lens wear or not (98% had staining regardless of lens wear or not (LBLB))12% of non12% of non--wearers and 62% of contact lens wearers and 62% of contact lens wearers had staining of more than grade 1 (wearers had staining of more than grade 1 (LBLB))32.5% of contact lens wearers but only 4.4% had 32.5% of contact lens wearers but only 4.4% had staining of more than grade 1 (staining of more than grade 1 (TERTCTERTC))338 338 vsvs 50 subjects (50 subjects (TERTC TERTC vsvs LBLB))

Corneal Staining in Hydrogel Lens WearersCorneal Staining in Hydrogel Lens WearersAbstract

Purpose. The purpose of this study was to determine the factors that contribute to corneal staining in hydrogel lens wearers by examining the following variables: type of lens worn, wearing time and lens replacement schedule, lens care system, and topical and systemic medication use.Methods. Five hundred full-time, successful hydrogel contact lens wearers were evaluated for corneal fluorescein staining at 20 clinical sites. Corneal staining was evaluated in five regions and was graded on a scale of 0 (no staining) to 4 (severe staining) in 0.5 steps for severity.Results. Corneal fluorescein staining was present in at least one eye in 55.7% of the hydrogel lens wearers examined in this study, and 8.0% had moderate-to-severe staining (defined as a cumulative staining score of >=3 with at least one quadrant score >=2). Staining was most severe for the inferior portion of the cornea (mean ± SD; OD: 0.34 ± 0.57, OS: 0.30 ± 0.54). All other areas of the cornea showed lesser amounts of staining, all of which were approximately equal (mean range, 0.13 to 0.16). Staining was observed in two or more quadrants in 24% of right eyes and 22.4% of left eyes. When questioned about care system compliance, 81.1% of subjects reported compliance. Patients who were noncompliant with their lens care system ([chi]2 p = 0.0037), used rewetting drops ([chi]2 p = 0.0005), or wore conventional lenses without a planned replacement schedule ([chi]2 p = 0.0008) were more likely to have some degree of corneal staining. Noncompliance with care system ([chi]2 p = 0.0147), replacement schedule ([chi]2 p = 0.0039), and lens power ([chi]2 p = 0.0224) were associated with moderate-to-severe staining. The following factors were not significantly associated with corneal staining: patient age, gender, medication use including oral contraceptives, type of wear (extended, flexible, or daily), average wearing time, wearing time at the examination, lens type (spherical or toric), water content of lenses (high or low water content), type of care system, use of enzymes, and pinching the contact lens directly off the cornea.Conclusions. Staining occurs to some extent in many hydrogel contact lens patients, and is influenced by many factors. Moderate-to-severe staining, which may be more clinically significant, is associated with noncompliance with care system, a conventional replacement schedule, and lens power.

NICHOLS, KELLY K. OD, MPH, PhD, FAAO; MITCHELL, G. LYNN MAS; STONEBRAKER SIMON, KAREN M. OD; CHIVERS, DAWN A. OD; EDRINGTON, TIMOTHY B. OD, MS, FAAO. Optometry and Vision Science, Vol 79(1), pp 20-30

TERTC Staining StudyTERTC Staining StudyPrevalencePrevalence

Compared with some studies on CL wearCompared with some studies on CL wearLower than other studies on CL wearers (Lower than other studies on CL wearers (egegNichols et al, 2002)Nichols et al, 2002)Possible explanations for lower prevalencePossible explanations for lower prevalence

TERTC study had:TERTC study had:higher number of higher number of SiHySiHy wearers wearers high number of daily disposable wearers. high number of daily disposable wearers. the application of the application of NaFlNaFl on to the ocular surface is not a on to the ocular surface is not a standardized procedure.standardized procedure.

ConclusionsConclusions

We believe that 33% and 20% of conjunctival We believe that 33% and 20% of conjunctival and corneal staining respectively may represent and corneal staining respectively may represent the incidence of staining that is at least expected the incidence of staining that is at least expected in a healthy, young population of soft contact in a healthy, young population of soft contact lens wearerslens wearers without economic incentive to be without economic incentive to be nonnon--compliant.compliant.

The importance of beginning to standardize the The importance of beginning to standardize the clinical measure of ocular surface staining clinical measure of ocular surface staining cannot be stressed enough. Without some cannot be stressed enough. Without some degree of protocol uniformity, it will remain degree of protocol uniformity, it will remain difficult to compare the findings of different difficult to compare the findings of different clinical studies. clinical studies.

ConclusionsConclusions

Ward (2008)Ward (2008)

Recently pointed out the great variability in Recently pointed out the great variability in NaFlNaFlstaining protocolsstaining protocols

What is staining?What is staining?

DesquamationDesquamationFluid uptakeFluid uptake

What is recorded as staining?What is recorded as staining?

1 1 punctatepunctate spot (grading scales give no guidance)spot (grading scales give no guidance)Conjunctival foldsConjunctival foldsPooling along palisades of VogtPooling along palisades of Vogt

(Miller WL, et al., Optometry, 2003)

It is recommended that clinicians develop and It is recommended that clinicians develop and adopt a universal standard protocol for this adopt a universal standard protocol for this measure.measure.

Staining IncidenceStaining Incidence

CL wearers (20CL wearers (20--56%)56%)NonNon--CL wearers (37CL wearers (37--77%)77%)

We need more We need more Reliable Information in Reliable Information in

PEER Reviewed LiteraturePEER Reviewed Literature

TERTC Clinical Studies:TERTC Clinical Studies:

Grade 0 and 1 always OKGrade 0 and 1 always OKGrade 2 sometimes OKGrade 2 sometimes OKGrade 3 and 4 not OKGrade 3 and 4 not OK

Suzanne Fleiszig OD, PhDSuzanne Fleiszig OD, PhDOSV, 2006OSV, 2006

““During the past 3 decades, various attempts During the past 3 decades, various attempts to solve the problem (bacterial infection) to solve the problem (bacterial infection) with new lens types and lens care products with new lens types and lens care products have failed to make a significant impact on have failed to make a significant impact on its incidence.its incidence.””

To eliminate CLTo eliminate CL--MK will require MK will require better understanding of:better understanding of:

Ocular defense systemOcular defense systemMicrobial virulence strategiesMicrobial virulence strategiesThe effect of the above 2 on each otherThe effect of the above 2 on each otherThe effects of CL wear on bothThe effects of CL wear on both

(Fleiszig, 2006)(Fleiszig, 2006)

Animal Model Experiment Animal Model Experiment ––Epithelial Injury with Epithelial Injury with NaFlNaFl stainingstainingand challenged with exposure to PAand challenged with exposure to PA

Simple injury did not lead to Simple injury did not lead to mirobialmirobial susceptablitysusceptablity..Conclusion:Conclusion:-- Injury in isolation from other Injury in isolation from other prediposingprediposing factors does factors does

not lead to MK.not lead to MK.

(Fleiszig, 2006)(Fleiszig, 2006)

Courtesy Barry Weissman

Stapleton et al., Ophthalmology, 2008Stapleton et al., Ophthalmology, 2008

Annualized incidence per 10,000 wearersAnnualized incidence per 10,000 wearers

-- In agreement to earlier reportsIn agreement to earlier reports-- New lens types have not reduced the incidenceNew lens types have not reduced the incidence-- Overnight use of any CL is associated with higher riskOvernight use of any CL is associated with higher risk

DW GP: 1.2DW GP: 1.2DW SCL: 1.9 DW SCL: 1.9 FW SCL: 2.2FW SCL: 2.2DD SCL: 2.0DD SCL: 2.0DDFW SCL: 4.2DDFW SCL: 4.2DW DW SiHySiHy: 11.9: 11.9FW FW SiHySiHy: 5.5: 5.5EW SCL: 19.5EW SCL: 19.5EW EW SiHySiHy: 25.4: 25.4

LetLet’’s review epithelial physiology s review epithelial physiology and morphologyand morphology

Epithelium Epithelium -- FunctionsFunctions

RefractionRefractionPhysical ProtectionPhysical ProtectionUVR ProtectionUVR ProtectionSecretion of MUC 1, 4, 16 Secretion of MUC 1, 4, 16 mucousmucousTear StabilizingTear StabilizingFluid BarrierFluid BarrierMicroorganism ShieldMicroorganism Shield

Epithelial NutritionEpithelial Nutrition

TearsTearsO2O2IonsIons

AqueousAqueousGlucose and other nutrientsGlucose and other nutrients

Circulation Circulation (limbus; palpebral conj.) (limbus; palpebral conj.) Glucose, OGlucose, O22 and other nutrientsand other nutrients

Palpebral ConjunctivaPalpebral ConjunctivaOO22

Ions Ions ??

Ions Essential to Epithelial HealthIons Essential to Epithelial Health

CalciumCalciumPotassiumPotassiumMagnesiumMagnesiumZincZinc

Epithelial health will not be Epithelial health will not be sustained by Sodium Chloride sustained by Sodium Chloride

without essential ionswithout essential ions

SquamousSquamous cell degenerationcell degenerationAccelerated exfoliationAccelerated exfoliationEpithelial thinningEpithelial thinning

Epithelial Renewal Epithelial Renewal –– X, Y, Z TheoryX, Y, Z Theory

Proliferations of basal cells (X) together with centripetal Proliferations of basal cells (X) together with centripetal movement of peripheral cells (Y) equals cell loss (Z) movement of peripheral cells (Y) equals cell loss (Z) from the surface (from the surface (ThoftThoft RA, Friend J, 1983).RA, Friend J, 1983).

(from Bergmanson, Clinical Ocular Anatomy and Physiology, 12th ed, 2005)

X, Y, Z Theory in PracticeX, Y, Z Theory in Practice

Epithelial ApoptosisEpithelial Apoptosis

Cell regeneration is controlled by stem cells in Cell regeneration is controlled by stem cells in limbus and palisades.limbus and palisades.Do we also have a controlled cell death Do we also have a controlled cell death (apoptosis)?(apoptosis)?This important research question is currently This important research question is currently being addressed by Danielle Robertson, OD, PhDbeing addressed by Danielle Robertson, OD, PhD

Epithelial Apoptosis in Epithelial Apoptosis in Normal Homeostatic ConditionNormal Homeostatic Condition

As cells prepare to die underlying cells secrete As cells prepare to die underlying cells secrete MUC 1, 4 & 16 and start forming tight junctions.MUC 1, 4 & 16 and start forming tight junctions.1% of the corneal epithelial surface cells are 1% of the corneal epithelial surface cells are undergoing apoptosis (undergoing apoptosis (RenRen, Wilson et al, 1996), Wilson et al, 1996)Genetically controlled event regulated by a Genetically controlled event regulated by a complex signal transduction cascade.complex signal transduction cascade.

Epithelial Desquamation Apoptosis:Epithelial Desquamation Apoptosis:

Is necessary to maintain normal thicknessIs necessary to maintain normal thicknessIs single cell sloughing observable with a Is single cell sloughing observable with a biomicroscopebiomicroscope??

A point of interest:A point of interest:

Palpebral accessory lacrimal Palpebral accessory lacrimal gland with gland with 100 100 ductalductal openings/mmopenings/mm22

The CL seals the cornea off The CL seals the cornea off from this vital from this vital tearflowtearflow and and nutritional support!nutritional support!And we do not know the effect of this blockage on epithelial health.

Superficial Superficial PunctatePunctate StainingStaining

More than one cell may have to be shed to leave a More than one cell may have to be shed to leave a large enough large enough punctatepunctate area to be observable clinically.area to be observable clinically.FluoresceinFluorescein sodium helps visualize this clinical entity.sodium helps visualize this clinical entity.Confocal microscopy not idealConfocal microscopy not idealAre underlying cells ready to take over?Are underlying cells ready to take over?

Corneal EpitheliumCorneal EpitheliumA Delicate and Complex StructureA Delicate and Complex Structure

Continuously regeneratedContinuously regeneratedMust recruit cells from other tissuesMust recruit cells from other tissuesMust support nonMust support non--epithelial cellsepithelial cellsMost sensitive part of the bodyMost sensitive part of the bodyMust be leak/microMust be leak/micro--organismorganism--proofproofParticipates in the ocular immune responseParticipates in the ocular immune responseIs a UVR filterIs a UVR filterNutrition must be obtained from at least 4 different Nutrition must be obtained from at least 4 different sources sources (T, A, LL, PC)(T, A, LL, PC)

A contact lens seals off OU important source (PC)A contact lens seals off OU important source (PC)

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What we really need is: What we really need is:

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