EFFECTS OF THE PINEAL-GLAND ON LIGHT-INDUCED RETINAL PHOTORECEPTOR DAMAGE

Light-induced retinal photoreceptor degeneration was compared in pinealectomized and sham-pinealectomized rats at 40, 50 and 60 days of age. There was no significant difference in retinal damage between pinealectomized and sham-pinealectomized rats when they were subjected to light treatment at 40 or 50 days. However, 60-day-old pinealectomized rats showed less photoreceptor damage than did 60-day-old intact sham-pinealectomized rats when both groups were exposed to light treatment. The results suggest that the pineal gland plays a role in retinal metabolism. An hypothesis to explain the results is discussed; the effects of the pineal gland on the susceptibility of the retinal to photic damage is speculated to be endocrine in nature. © 1979.