An Ultrastructural Study of Recovery of Photoreceptor Layer from Visible Light-Induced Damage

ABSTRACT

Visible light can induce damage to the susceptible retina and its injurious effect has been studied morphologically and functionally in detail. In order to evaluate the regenerative processes of the retina damaged by visible light in correlation with the degree of the cellular damage, the rat retina was exposed to blue visible light (400-500nm) for 30, 60 and 120 minutes, and examined electron microscopically, immediately and 1, 2, 3, 4, 5 weeks after the exposure. The results were as follows. The more increased time of exposure by visible light, the more damage to the photoreceptor, and the more delay in the recovery. We observed the recovery of damage was generally slow, and the pigment epithelium necessary for regeneration of discs was not destroyed in spite of long term exposure of visible light.