A Parametric Study of Retinal Light Damage in Albino and Pigmented Rats

Abstract

Although light serves as the adequate stimulus for vision, it can, under certain conditions, have a deleterious effect on the retina. Using rats as experimental animals, Noell et al. (1) were the first to demonstrate that morphological and functional damage to the retina can result from constant light exposures of only a few hours. The manifestations of damage to the retina included the deterioration and death of the photoreceptors with concurrent losses in the amplitude of the electroretinogram (ERG). Moderate light intensity (1,200 to 2,500 lux), several log-units lower than the levels found necessary to produce threshold retinal burns, was used to produce damage. The action spectrum of the damage corresponded to the absorption spectrum of rhodopsin, the rat’s visual pigment, indicating that damage is initiated by the same primary photochemical event as is vision.