Distribution of ascorbate in normal primate retina and after photic injury: a biochemical, morphological correlated study

Abstract

The levels of reduced and oxidized ascorbates were determined in the normal baboon neural retina and pigment epithelium-choroid. The ascorbate in the neural retina was mainly in the reduced form, while in the pigment epithelium, it existed primarily in the oxidized form. One eye of each of six baboons was exposed to indirect ophthalmoscope light for 30 minutes. Morphologic study showed necrotic photoreceptors, outer segment disorganization, and abnormal pigment epithelial basal infoldings and swollen microvilli. After the light exposure, the values of the reduced ascorbate decreased in both the neural retina and pigment epithelium-choroid of the posterior pole. The possible role of ascorbate as an antioxidant and ascorbate transport into the retina are discussed.