[Change in interphotoreceptor-retinoid-binding-protein (IRBP) after retinal photocoagulation and cryopexy]

Effects of retinal photocoagulation and cryopexy on the interphotoreceptor-retinoid-binding-protein (IRBP) were studied using the indirect enzyme-labeled antibody technique. Following photocoagulation or cryopexy of eyes of normal guinea pigs, the eyes were fixed and frozen sections were reacted with rabbit anti-bovine IRBP serum as a primary antibody and with horseradish-peroxidase-conjugated anti-rabbit IgG goat IgG Fab' fragment as a secondary antibody. A positive reaction for IRBP was noted up until 7 days after photocoagulation. However, although IRBP was also noted in almost all layers of the retina immediately following cryopexy, it disappeared with time as the retina atrophied. We postulate that, because IRBP is an extracellular substance produced by the visual cell, it tended to remain in the photoreceptor layer following milder destruction with photocoagulation, but disappeared completely with atrophy of visual cells following cryopexy.