Updated: March 7, 2007
Understanding Corneal Staining and Responding to Andrasko Material and data provided by Lynn Lasswell, OD, Stan Huth, MA, Denise Tran, BS, Cheryl Skotnitsky, OD, PhD
What is staining? Staining with a topical dye is a clinical procedure used to observe the integrity and vitality of the epithelial cells of the ocular surface Fluorescein, Rose Bengal and lissamine green dyes are used in different staining procedures
Corneal staining with fluorescein dye Orange fluorescein dye absorbs blue light and emits green light. Stains corneal defects upon application by diffusing between cells and adjacent intercellular spaces and penetrating into the underlying stroma. Stains whenever there is disruption of cell-cell junctions. Intensity of the stain increases with cell degeneration or death due to membrane & junction damage. Can stain healthy cells. Staining is not blocked by tear components such as albumen and mucin. Detects epithelial defects and assists in the diagnosis of erosions, corneal abrasion and keratitis. Very useful in detecting permeability of the epithelium and endothelium. Molecular structure, with 2 negative charges
Topical application of fluorescein: the orange dye is released from commercially available sterile paper strips by wetting the strips with sterile saline and then touching the conjunctiva Assessment of the “Red Eye” September 20, 2006 http://eyelearn.med.utoronto.ca/Lectures04-05/RedEye/12Abrasion.htm> Sept 20, 2006
Punctate (point-like) fluorescein staining of cornea epithelium arising from solution toxicity
What amount of staining is considered acceptable? Corneal fluorescein staining occurs occasionally in virtually everyone, including contact lens and non-contact lens wearers. Trace punctate or pinpoint fluorescein staining can occur in healthy, normal individuals as a result of a normal cornea expressing epithelial turnover of dying surface cells undergoing replacement with new cells arising from below. Dundas M. Walker A. Woods RL. Clinical grading of corneal staining of non-contact lens wearers. Opthalmic Physiol Opt 2001; 21:30-5
Accepted Staining Methodologies Efron CCLRU (Sydney, Australia) CCLR (University of Waterloo, Canada)
Efron Staining Scale
Efron Staining Scale 5 cornea sectors 5 point scale
Efron staining scale 5 Point Scale Grade 0: Not significant Grade 2: Requires monitoring Grade 3: Therapeutic Intervention Grade 4: Treatment
Cornea and Contact Lens Research Unit (CCLRU) School of Optometry and Vision Science, The University of New South Wales, Sydney, Australia
CCLRU standard for corneal staining with fluorescein TYPE DEPTH EXTENT
Punctate (point-like) fluorescein staining types are determined for each cornea zone 1: micropunctate 2: macropunctate 3: coalesced macropunctate 4: patch (≥ 1mm) 0: none
Punctate (point-like) fluorescein staining of cornea epithelium: CCLRU types Type 2: Macropunctate 30% of central zone Type 4: Patch 30% of nasal zone
CCLRU Example Zone Type Depth Extent Clinical Significance determined by zone with greatest staining: Type is greater than Grade 2 (macropunctate) and/or Depth is greater than Grade 1 (superficial epithelial involvement) Extent is greater than Grade 1 (1-15% surface involvement) Zone Type Depth Extent Zone 1 10% Zone 2 1 2 20% Zone 3 4 30% Zone 4 Zone 5 3
Lyndon Jones, University of Waterloo CCLR Lyndon Jones, University of Waterloo
CCLR (University of Waterloo) CCLRU expanded by Dr. Jones, University of Waterloo Changed 0-4 staining type to 0-100 type 25=micropunctate 50=macropunctate 75=coalesced macropunctate 100= patches Continues to use 5 zones Multiplies staining type by percentage area of zone Result ranges from 0-10,000 per zone, 0-50,000 global
CCLR Example 3 4 1 5 2 3 Global Score < 6000 or T=25 %=10 1 T=50 %=20 5 %=30 T=0 %=0 2 3 Zone 1: 50 (macro) x 20= 1000 Zone 2: 0 Zone 3: 50 (macro) x 20= 1000 Zone 4: 25 (micro) x 10= 250 Zone 5: 50 (macro) x 30= 150 1000 250 + 1500 3750 Global Score 3750/5= 750 Average Sector Score Global Score < 6000 or Average Sector score < 1200 is clinically insignificant
Andrasko corneal staining grid Andrasko study Staining method Results Andrasko et al., “Ocular Response Observed with Silicone Hydrogel Lenses and Multi-purpose Solution Combinations” June 2006 Poster <http://www.staininggrid.com/gridmain.aspx> Sept. 21, 2006
“Nearly all corneal staining was micropunctate”- Andrasko Poster Andrasko Study Design A series of randomized, double-masked, crossover studies consisting of 9-14 subjects each were run. Subjects with staining at baseline were excluded from the study. Prior to wear, the contact lenses were soaked for 12 hrs in the solution tested. Subject’s cornea was examined with fluorescein, cobalt filter and a yellow filter at baseline (after 15 minutes of lens wear), and after 2 hours and 4 hours of lens wear. Len/solution comfort was evaluated with a 100 point scale at baseline and after 2 hours and 4 hours of lens wear. “Nearly all corneal staining was micropunctate”- Andrasko Poster Staining Grid chart depicts only average percent staining across all zones.
Lenses and Solutions Studied Contact Lens AcuVue 2 Proclear Acuvue Advance AcuVue Oasys PureVision O2 Optix Focus Night and Day BioFinity Solution Unisol Clear Care Opti-Free Express Opti-Free Replenish Renu MoistureLoc Renu Multi-Plus Walmart MPS (Renu MP) Target MPS (Renu MP) Complete MoisturePlus AQuify
Andrasko Staining Method Corneal staining was examined according to the following scale. The cornea was divided into five zones and staining was evaluated according to type (0-4) and area (0-100%) for each zone.
Average corneal staining results with each lens type at baseline, after 2 hrs, and after 4 hours of lens wear. For the most part, baseline to the 2 hr point showed the greatest increase in staining area Nearly all corneal staining was micropunctate, type 1.
Andrasko comfort vs. staining results The only comfort data reported was for PureVision™ Found a moderate, inverse correlation between comfort and staining at 4 hours of lens wear across all combinations of MPS and contact lenses. (i.e, high staining, low comfort) The plot below is of PureVision ™ lens only. It shows the average comfort rating at each visit, with the staining area % noted in parentheses.
Andrasko Staining Grid Lens and Solution Combinations Percentage of Average Corneal Staining Area at 2 Hours Unisol1 4 Saline Clear Care4 Opti-free Express1 Opti-free Replenish1 Renu Moistureloc3 Renu Multiplus3 Walmart MPS Target MPS Complete Moisture Plus2 Aquify4 Acuvue5 2 1% 2% 5% 25% Acuvue Advance5 No Further Tesing 13% 16% 20% Acuvue Oasys5 Testing Ongoing 3% 10% 9% 12% Purevision3 6% 7% 73% 71% 48% 21% O2 Optix4 24% 41% 18% Focus Night & Day4 4% 36% Updated: September 19, 2006 H2O2 POLYQUAD Biguanides Lens and Solution Combinations Percentage of Average Corneal Staining Area at 2 Hours under 10% 10% to 20% over 20% Note: the CCLRU acceptance standard for % area is up to 15% when only micropunctate type 1 staining is present http://www.siliconehydrogels.org/grading_scales/DATA/back_page.htm
Andrasko Staining Grid Lens and Solution Combinations Percentage of Average Corneal Staining Area at 2 Hours Unisol1 4 Saline Clear Care4 Opti-free Express1 Opti-free Replenish1 Renu Moistureloc3 Renu Multiplus3 Walmart MPS Target MPS Complete Moisture Plus2 Aquify4 Acuvue5 2 1% 2% 5% 25% Acuvue Advance5 No Further Tesing 13% 16% 20% Acuvue Oasys5 Testing Ongoing 3% 10% 9% 12% Purevision3 6% 7% 73% 71% 48% 21% O2 Optix4 24% 41% 18% Focus Night & Day4 4% 36% Updated: September 19, 2006 H2O2 POLYQUAD Biguanides Lens and Solution Combinations Percentage of Average Corneal Staining Area at 2 Hours Same Products! under 10% 10% to 20% over 20%
Summary response to Andrasko Only Type 1 micropunctate staining was found: this is common, even among non-lens wearers Subjective estimates of % surface area are unreliable- staining results for the same solution varied by 17% in Andrasko (ReNu Multiplus = 24% and Walmart MPS = 41%; yet they are the same solution!) The standard of acceptance for Type 1 micropunctate staining is ≤ 15% of the surface area for any sector, not 10% per Andrasko (Table II and ref. 15 in Snyder article) Andrasko mixed studies to provide results (e.g., O2 Optix: OFX= 2%, CMP = 4.5% and Aquify = 7% in same study/ population. Andrasko reported 18% for CMP instead, taken from another study. Our own SH compatibility studies, including staining, show CMP produces no significant staining with SH lenses, except PV
Studies
0-4 staining scale used, summed scores for each of 5 corneal zones An 8% incidence of moderate-to-severe staining among contact lens wearers is not uncommon and can arise from factors other than the care system Nichols KK, Mitchell GL, Simon KM, Chivers DA, Edrington TB. Corneal staining in hydrogel lens wearers. Optom Vis Sci 2002;79:20-30. 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: 500 full-time, successful hydrogel contact lens wearers were evaluated for corneal fluorescein staining. 0-4 staining scale used, summed scores for each of 5 corneal zones Moderate (Grade 3) to severe (Grade 4) = cumulative score ≥ Grade 3 with at least one quadrant score ≥ 2.
Nichols staining study results 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. 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 systems, a conventional replacement schedule (not planned replacement or disposable lenses), and higher plus or minus lens powers (>3 diopters).
Comfort
Relationship of staining to comfort For Your Understanding: Corneal staining associated with hydrogel contact lens wear may or may not be associated with patient symptoms
Relationship of staining to comfort Study Design: At least 40 subjects in each cell Subjects wore one of a range contact lenses for up to 3 months with disposal as per label Silicone hydrogel lenses and multi-purpose solutions studied ACUVUE ™ ADVANCE™ ACUVUE ™ OASYS™ PureVision™ O2 Optix™ Focus ™ Night & Day™ Examined solution toxicity, defined as diffuse punctate staining Subjects rated comfort on a scale of 1-10 (1=poor, 10=excellent) AOSEPT ClearCare ™ AQuify ™ ReNu with MoistureLoc ™ OPTIFREE EXPRESS ™ OPTI-FREE RepleniSH ™ Tilia et al., Institute for Eye Research, Australia Papas et al. “Solution Toxicity in Soft Contact Lens Daily Wear is Asociated with Corneal Inflammation” Poster
Relationship of staining to comfort Subjects were asked to rate their experience with their lenses on a scale of 1 to 10, where 1= poor and 10= excellent. Controls Toxic Staining Group Subjects experiencing solution toxic staining report lower than average comfort ratings than those who do not: upon insertion of the lens (7.9±2.0 vs 8.4±1.6, p=0.02) and at the end of the day (6.7±2.1 vs 7.2±2.1, p=0.04 ). Tilia et al., Institute for Eye Research, Australia Papas et al. “Solution Toxicity in Soft Contact Lens Daily Wear is Asociated with Corneal Inflammation” Poster
Chart 1 Bausch & Lomb EyeMatters newsletter, Vol. 9-September 2006 Recognizing the Clinical Realities of Corneal Staining
Corneal Staining Summary 3 major staining methodologies Regional preference High degree of subjectivity Great variability between practitioners Need to drive wedge between Andrasko results and accepted staining methods Call results into question Nearly all staining was micropunctate Multiple studies and patient populations were used Identical products had vastly different results No statistical significance identified Transition to AMO data Neutral Red Retention 5 studies in EVA on compatibility Get back on message Tear quality Maintains corneal integrity 2 Demulcents Eliminates microbial contamination from lens Highly effective
Trademarks The AMO logo, Blink-N-Clean, COMPLETE, the COMPLETE logo, COMPLETE MoisturePLUS and ULTRACARE are registered trademarks and Blink Contacts is a trademark of Advanced Medical Optics Inc. OPTI-FREE, EXPRESS and REPLENISH are registered trademarks of Alcon, Inc. RENU, MULTI-PLUS and MOISTURELOC are registered trademarks of Bausch & Lomb, Inc. ACUVUE, ACUVUE 2, and ADVANCE are registered trademarks and ACUVUE Oasys is a trademark of Johnson & Johnson Corporation. AQUIFY and NIGHT & DAY are registered trademarks and O2OPTIX is a trademark of Novartis AG Corporation. CLEAR CARE is a registered trademark of CIBA Vision. REFRESH and REFRESH Contacts are registered trademarks of Allergan, Inc.