The 21-aminosteroids or lazaroids are a novel series of compounds being developed for the acute treatment of traumatic or ischemic injury of the nervous system. These compounds were specifically designed to localize within cell membranes and inhibit lipid peroxidation reactions. In this study, 21-aminosteroid U75412E was injected into the vitreous body of rabbit eyes to evaluate its suitability for intraocular injection and its toxicity on intraocular tissues. Doses ranged from 20 g to 200 g. Retinal toxicity was determined through light and transmission electron microscopy and electroretinography. No retinal toxicity was noted in doses of 30 g and below.