Antiphlogistic effect of catalase on experimental phacoanaphylactic endophthalmitis.

Oxygen-derived free radicals generated by polymorphonuclear leukocytes have recently been implicated as important pathogenic mediators of tissue damage in immune complex-mediated acute inflammatory reactions. In order to study the role of oxygen radicals in experimentally induced phacoanaphylactic endophthalmitis, rats were immunized with soluble bovine lens protein and, following surgical disruption of the anterior lens capsule, subjected to treatment with catalase. Our data show that phacoanaphylactic endophthalmitis, as determined morphologically and by measurements of retinal edema, choroidal inflammation, retinal hemorrhage and necrotizing vasculitis, is greatly diminished in catalase-treated animals. This protective effect of catalase indicates that hydrogen peroxide (H2O2) and/or conversion products of H2O2 (e.g., hydroxyl radical, hypochlorous acid) may play an important role in the development of experimental phacoanaphylactic endophthalmitis.