Protective Effect of Cysteine against Retinal Degeneration induced by lodate and by lodoacetate

Abstract

ACUTE degenerative lesions of the neuro-epithelium and of the pigment layer of the retina can be readily induced in the rabbit by a single intravenous injection of five different agents, namely, sodium iodate¹, sodium iodoacetate², dithizone³, the primary phenoxyalkanes⁴ and sodium fluoride⁵. To be effective, sodium iodoacetate and sodium fluoride have to be given in sub-lethal doses, and only some 66 per cent and some 20 per cent, respectively, of animals treated with these agents show ophthalmoscopic lesions. With the remaining substances, well-tolerated doses produce retinal lesions in all rabbits treated. The severity of the lesion produced by an agent varies from animal to animal, so that it is difficult to be sure whether there is a fundamental difference between the reactions produced by these five agents ; however, dithizone probably gives the most severe and rapidly developing lesion, while sodium fluoride gives the most localized reaction ophthalmoscopically and histologically. Ophthalmoscopic lesions are occasionally seen within a matter of a few hours, but more often not until about 48 hr. ; fully established lesions are present almost always within 5 days.