[Light-induced retinal damage in pigmented rabbit--2. Effect of alpha-tocopherol]

We have reported previously that xenon light exposure without long waves primarily damages the retinal pigment epithelium (RPE) of pigmented rabbits. Alpha-tocopherol, which is a free radical scavenger, was administered systemically to pigmented rabbits before light exposure in order to evaluate the protective effect against retinal light damage. In fluoresceine angiography, at 12 hours after the light exposure, diffuse and marked hyperfluorescence was seen in the lower portion of the retina adjacent to the optic disc in the untreated group, and slight hyperfluorescence in a small area was seen in the treated group. Histopathologically, the RPE became necrotic 12 hours after the light exposure in the untreated group. In the treated group, only slight damage appeared in the RPE 12 hours after the light exposure. The light-induced retinal damage, particularly in the RPE, was remarkably reduced by administration of alpha-tocopherol before the light exposure.