Retinal Damage by Visible Light: An Electron Microscopic Study

Abstract

SEVERE damage to the retina by exposure to light has recently been demonstrated by Noell 1,2 and by us. 3,4 To establish the pathogenetic mechanisms, a series of electron microscopic studies of the retinas which had been exposed to lights under several conditions has been in progress in this laboratory. Depending on the duration of the light exposure and the nature of the light sources, the retinas show damage varying all the way from total degeneration of the whole retina to minimal changes in the photoreceptors. Upon exposure to relatively cold light at a brightness of approximately 750 foot-candles (ft-c), photoreceptic outer segments of the albino rat demonstrate remarkable membranous changes. The purpose of this paper is to describe such changes in the photoreceptic cells and to discuss the mechanisms of the damage. Materials and Methods Albino rats were mainly used in the experiment. Ordinary wire mesh animal cages