Nutritionally induced retinal degeneration in rats.

Nondystrophic RCS rdy+ rats were fed a vitamin E-deficient diet for a period of 3 mo. Light and electron microscopic examination revealed degenerative alterations in retinal tissue in the form of a reduction in the thickness of the outer nuclear layer, shortening of the photoreceptor outer segments, and extreme thinning of the pigment epithelial cells, including a reduction in the number of cell organelles. These changes may be a result of increased lipid peroxidation activity in the retina, because vitamin E is known to have a protective antioxidant effect in many tissues. Some of the alterations are similar to those found in hereditary retinal dystrophies.