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Contact lens induced conjunctivitis: A model of human ocular inflammation
.Abstrll“t.~ ocular response (slit-lamp biomicroscopy); (8) cornea1 thickness; (9) refractive changes; (10) visual acuity (10 and 90% contrast with Lovie Bailey charts). The results of all assessments were compared with the baseline values taken at Week 2. Respectively, the results of these assessments indicated: ( 1) no change in NIDUT between groups at each visit or over time; (2) significant increase in surface mucus over time in Group II and no significant change in Group I; (3) significant increase in protein deposition over time in both groups but no difference between groups; (4) significantly increased surface scratching in both groups, with the rate of increase significantly higher in Group II; (5) both groups reported lens binding, but this was reported more frequently by Group II, with a significantly higher frequency in Group II by 12 months; (6) no significant differences in comfort between groups, with no trends over time; (7) significant increase in cornea1 staining seen in Group II but not in Group I, with both groups showing a significantly increased level of microcysts over time with no difference between groups. Both groups showed a significantly increased tarsal conjunctival response with no difference between groups; (8) no differences in cornea1 thickness were found; (9) both groups showed an increase in myopia over time, but this was significant only for Group II, and it is believed that the increased myopia observed may be due to expected myopic creep and could be considered to be clinically insignificant; (10) 90% contrast logMAR acuity was significantly lower in Group II (but not to a clinically significant degree); this was not found for Group I. No changes in 10% contrast logMAR acuity were found. The frequent replacement of RGP lenses may offer advantages in terms of increased lens wetability, decreased incidence of lens binding, and decreased cornea1 staining. Although the exact optimal replacement interval for extended RGP wear cannot be calculated from the data generated by this study, the authors suggest that a 3- to 6-month replacement schedule would be simple to administer and may help to avoid changes in lens and ocular integrity, particularly, lens binding.
Contact Lens Induced Conjunctivitis: A Model Human Ocular Inflammation. Friedaender MH: CLAO J 1996;22:205-208.
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Contact lens-induced conjunctivitis (CLIC) includes a broad group of patients with contact lens irritation. They may have upper tarsal conjunctiva “micropapillae” (diameter, ~0.3 mm), “macropapillae” (0.3-I mm in diameter), or “giant papillae” (diameter, >l mm). Only those exhibiting “giant papillae” can be considered as true giant papillary conjunctivitis (GPC) sufferers. The author suggests
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that CLIC is a convenient model of human ocular mtlammation for evaluating the anti-inflammatory effects of nIpical pharmaceuticals. The rationale underlying this assertion states that subjects with CLIC can he recruited in large numbers and have low-grade but persistent irritati\~e signs and symptoms (that are easily evaluated) and that total contact lens wear time and wear time until discomf~~rt develops can be easily quantified. To evaluate this model, the author investigated the effects of two antiallergic eyedrops (ketorolac tromethamine, KT; lodoxamide tromethamine, LT) on the signs and symptoms of CLIC sufferers. Forty subjects were recruited, selected on the basis of positive CLIC signs (papillary reaction of the upper tarsal conjunctiva, erythema of the upper tarsal conjunctiva, bulbar conjunctival injection, and discharge) and symptoms (foreign body sensation, burning/stinging, itching, discharge, redness, photophobia, tearing, and dryness). Twenty subjects were randomly assignedto each of the trial medications, KT and LT, in a double-blind manner. Subjects were askedto instill artificial tears (Refresh@)four times per day for the first 3 days and to commencetheir courseof study medication four times per day on Day 4. Signs and symptomswere evaluated at baseline,Day 7 and Day 14. The subjectsalso kept a daily diary of contact lens wear time and wear time until the onset of irritation. At baseline, there were no significant differences, in term of symptoms and signs, found between the two groups.A significant difference between the groups’daily lens-wearingtimes was found (KT, 10.5 hours; LT, 13.8 hours), but a significant difference was not found between the two groups’wearing time until discomfort developed (KT, 5.4 hours; LT, 6.6 hours). By Day 7, only the LT group had a significantly lower symptom score, but by Day 14, both treatment groups had a significantly lower symptom score than at baseline. On Days 7 and 14, there was no significant difference between the symptom scoresof the two groups.The sign scoresof both groupswere significantly lower than at baselineon Days 7 and 14. Again, no significant difference between treatment groupswasdetected. The only significant difference in contact lens daily-wear time detected suggestedthat the KT group had an improved wear time in comparisonto the LT group at Day 14. Neither group displayed an increasedduration of contact lens wear for discomfort to develop, even by Day 14. Both drugsusedworked well for the reduction of CLIC symptoms.LT appearedto have a more rapid effect than KT; however, increasedwearing time wasonly noted with KT at Day 14. The author was careful to stressthat this study should not be taken asjustification for the useof pharmaceuticalssuch as KT and LT in the managementof CLIC. However, this study doessuggestCLIC to be a convenient model of ocular inflammation that may be useful in evaluating the efficacy of available and novel topical ocular anti-inflammatory pharmaceuticals.
Craig and Blades Jennifer P. Craig, PhD, MCOptom, is currently a postdoctoral research fellow in the Department of Vision Sciences at Glasgow Caledonian University in Scotland. Her main research interest is the physiology of the tear film in normal and dry eyes. Jennifer obtained a first-class honors degree in optometry in 1991 from the same institution, then known as Glasgow Polytechnic. After a year’s experience within the Hospital Eye Service, she attained a professional membership in the British College of Optometrists in 1992. Returning to Glasgow Caledonian University the same year, Jennifer undertook a 3-year studentship, under the supervision of Professor Alan Tomlinson, and was awarded a PhD, for research into tear physiology, in 1995. She has won numerous prizes to date, including the Naylor Prize and several prizes from the Scottish Committee of Optometrists. Kenny Blades, BSc(Hons), is a postgraduate student in the Department of Vision Sciences at Glasgow Caledonian University in Scotland. Under the supervision of Sudi Patel, he is currently researching the potential role of antioxidant therapy in the management of marginal dry eye and is hoping to complete his PhD program, within the next year. Studying physiology at St. Andrew’s University in Scotland, Kenny was awarded an upper second-class honors degree in 1993. During the q-year course, he also studied psychology, logic, and pholosophy of scienc as minor subjects and his senior honors project involved the investigation of a 5-HT (serotonin)-dependent sensory pathway in the skin of Xenopus embryos.
ICLC, Vol. 23, November/December
1996
245
Contact Lens Induced Conjunctivitis: A Model Human Ocular Inflammation. Friedaender MH: CLAO J 1996;22:205-208.
of
Contact lens-induced conjunctivitis (CLIC) includes a broad group of patients with contact lens irritation. They may have upper tarsal conjunctiva “micropapillae” (diameter, ~0.3 mm), “macropapillae” (0.3-I mm in diameter), or “giant papillae” (diameter, >l mm). Only those exhibiting “giant papillae” can be considered as true giant papillary conjunctivitis (GPC) sufferers. The author suggests
244
/C/X,
Vol. 23, November/December
1996
that CLIC is a convenient model of human ocular mtlammation for evaluating the anti-inflammatory effects of nIpical pharmaceuticals. The rationale underlying this assertion states that subjects with CLIC can he recruited in large numbers and have low-grade but persistent irritati\~e signs and symptoms (that are easily evaluated) and that total contact lens wear time and wear time until discomf~~rt develops can be easily quantified. To evaluate this model, the author investigated the effects of two antiallergic eyedrops (ketorolac tromethamine, KT; lodoxamide tromethamine, LT) on the signs and symptoms of CLIC sufferers. Forty subjects were recruited, selected on the basis of positive CLIC signs (papillary reaction of the upper tarsal conjunctiva, erythema of the upper tarsal conjunctiva, bulbar conjunctival injection, and discharge) and symptoms (foreign body sensation, burning/stinging, itching, discharge, redness, photophobia, tearing, and dryness). Twenty subjects were randomly assignedto each of the trial medications, KT and LT, in a double-blind manner. Subjects were askedto instill artificial tears (Refresh@)four times per day for the first 3 days and to commencetheir courseof study medication four times per day on Day 4. Signs and symptomswere evaluated at baseline,Day 7 and Day 14. The subjectsalso kept a daily diary of contact lens wear time and wear time until the onset of irritation. At baseline, there were no significant differences, in term of symptoms and signs, found between the two groups.A significant difference between the groups’daily lens-wearingtimes was found (KT, 10.5 hours; LT, 13.8 hours), but a significant difference was not found between the two groups’wearing time until discomfort developed (KT, 5.4 hours; LT, 6.6 hours). By Day 7, only the LT group had a significantly lower symptom score, but by Day 14, both treatment groups had a significantly lower symptom score than at baseline. On Days 7 and 14, there was no significant difference between the symptom scoresof the two groups.The sign scoresof both groupswere significantly lower than at baselineon Days 7 and 14. Again, no significant difference between treatment groupswasdetected. The only significant difference in contact lens daily-wear time detected suggestedthat the KT group had an improved wear time in comparisonto the LT group at Day 14. Neither group displayed an increasedduration of contact lens wear for discomfort to develop, even by Day 14. Both drugsusedworked well for the reduction of CLIC symptoms.LT appearedto have a more rapid effect than KT; however, increasedwearing time wasonly noted with KT at Day 14. The author was careful to stressthat this study should not be taken asjustification for the useof pharmaceuticalssuch as KT and LT in the managementof CLIC. However, this study doessuggestCLIC to be a convenient model of ocular inflammation that may be useful in evaluating the efficacy of available and novel topical ocular anti-inflammatory pharmaceuticals.
Craig and Blades Jennifer P. Craig, PhD, MCOptom, is currently a postdoctoral research fellow in the Department of Vision Sciences at Glasgow Caledonian University in Scotland. Her main research interest is the physiology of the tear film in normal and dry eyes. Jennifer obtained a first-class honors degree in optometry in 1991 from the same institution, then known as Glasgow Polytechnic. After a year’s experience within the Hospital Eye Service, she attained a professional membership in the British College of Optometrists in 1992. Returning to Glasgow Caledonian University the same year, Jennifer undertook a 3-year studentship, under the supervision of Professor Alan Tomlinson, and was awarded a PhD, for research into tear physiology, in 1995. She has won numerous prizes to date, including the Naylor Prize and several prizes from the Scottish Committee of Optometrists. Kenny Blades, BSc(Hons), is a postgraduate student in the Department of Vision Sciences at Glasgow Caledonian University in Scotland. Under the supervision of Sudi Patel, he is currently researching the potential role of antioxidant therapy in the management of marginal dry eye and is hoping to complete his PhD program, within the next year. Studying physiology at St. Andrew’s University in Scotland, Kenny was awarded an upper second-class honors degree in 1993. During the q-year course, he also studied psychology, logic, and pholosophy of scienc as minor subjects and his senior honors project involved the investigation of a 5-HT (serotonin)-dependent sensory pathway in the skin of Xenopus embryos.
ICLC, Vol. 23, November/December
1996
245