Effects of Topical Anti-inflammatory and Antiallergic Eyedrops on Prostaglandin E2–Induced Aqueous Flare Elevation in Pigmented Rabbits

OBJECTIVE: To evaluate the role of topical instillation of anti-inflammatory or antiallergic agents on experimental elevation of aqueous flare induced by prostaglandin E2 (PGE2) in pigmented rabbits. METHODS: Transcorneal diffusion of PGE2, 25 microg/mL (7.09 x 10 (-2)mmol/L), by means of a glass cylinder produced aqueous flare elevation. Anti-inflammatory or antiallergic agents were topically administered once or twice before PGE2 application. Aqueous flare was measured with a laser flare-cell meter. Results are given as mean +/- SD. RESULTS: Double instillations of 0.1% betamethasone sodium phosphate and 0.1% fluorometholone acetate at 4 and 2 hours before PGE2 application inhibited 61% +/- 11% and 46% +/- 14%, respectively, of flare elevation. Double instillations of 0.1% diclofenac sodium and 0.1% pranoprofen at 4 and 2 hours before PGE2 application did not inhibit flare elevation. Double instillations of 0.1% betamethasone, 0.1% fluorometholone, 0.1% diclofenac, and 0.1% pranoprofen at 1 and 0.5 hour before PGE(2) application inhibited 16% +/- 10%, 16% +/- 6%, 24% +/- 9%, and 23% +/- 10%, respectively, of flare elevation. Double instillations of 2% cromolyn sodium, 0.5% tranilast, 0.025% levocabastine hydrochloride, 0.1% pemirolast potassium, and 0.01% ibudilast at 1 and 0.5 hour before PGE2 application did not inhibit flare elevation. Single instillation of 0.1% betamethasone 6 hours before PGE2 application inhibited 88% of PGE2-induced aqueous flare elevation. Single instillation of 0.1% diclofenac 1 hour before PGE2 application inhibited 23% of PGE2-induced aqueous flare elevation. CONCLUSIONS: Betamethasone needed several hours after topical instillation to inhibit flare elevation, but diclofenac needed 1 hour. Antiallergic agents did not affect disruption of the blood-aqueous barrier in rabbits. CLINICAL RELEVANCE: Corticosteroid eyedrops may need several hours from instillation to show action.