RESUMO
Acute immunogenic uveitis was modeled in rabbits via the subcutaneous and intravitreal injections of normal horse serum. We studied the effect of instillations of 0.1% melatonin solution on the clinical course of uveitis and biochemical parameters of tear fluid and aqueous humor: antioxi-dant activity, protein concentration and α(2)-macroglobulin level. Melatonin instillations decreased clinical manifestations of uveitis. We found that the antioxidant activity in tears of the rabbits treated with melatonin was substantially higher and the α(2)-macroglobulin level lower than in untreated animals. Antioxidant activity in aqueous humor taken on day 10 of uveitis was also twice higher while protein and α(2)-macroglobulin levels were 1.5-2 times lower than in untreated animals. These data indicate that instillations of melatonin increase the local antioxidant activity and decrease the acuity of inflammation and permeability of hematoophthalmic barrier in uveitis.