Abstract

Sprague-Dawley rats, age 20-24 weeks, were obtained from Zivic-Miller Laboratories with unilateral intracranial optic nerve sections which did not interrupt the blood flow or any other innervation to the eye. They were then kept in uniform illumination of 1000 lx continuously for 24 h. The outer nuclear layer (ONL) areas of the two eyes in the same animal were compared five days postexposure. Light of this intensity causes damage primarily to the photoreceptors in the retina of the albino rat. Since the ONL of the retina contains photoreceptor cell bodies, reduction in the area of this layer is proportional to the number of cells lost due to the bright light exposure. Although the ONL area was reduced in both eyes, the retina with the intact optic nerve had an ONL area which averaged ~25 % less than that in the other eye with the optic nerve cut. Controls with unilateral optic nerve sections performed in the same manner but not exposed to damaging light showed no difference in ONL area between the two eyes. A second experiment using pigmented rats gave similar results. These results suggest a role for the brain in retinal light damage.

© 1985 Optical Society of America