Eight patients (16 eyes) developed ocular toxicity while undergoing intravenous deferoxamine mesylate (Desferal®) chelation therapy for transfusional hemosiderosis. Presenting symptoms included decreased visual acuity, color vision abnormalities, and night blindness. Six patients presented as presumed retrobulbar optic neuropathy demonstrating central scotomas and color vision abnormalities. The remaining two patients presented with pigmentary changes confined either to the macula or equator. Following cessation of therapy, vision improved in all but four eyes, which did not attain their pretreatment visual acuity. Optic neuropathy resolved in all cases. However, followup revealed development of retinal pigmentary degeneration in seven patients, involving the macula in six and the equatorial retina in one. Fluorescein angiography and electrophysiological tests suggested toxicity at the level of retinal pigment epithelium and photoreceptors