A 30-year-old previously healthy man presented with a superior visual field deficit in the left eye. His visual acuity was 20/20 OU. A dilated examination revealed areas of yellowish plaques along arterioles in the right eye and areas of capillary and arteriolar nonperfusion not involving branch points of the left inferior retina (Figure). An extensive serum laboratory workup had negative results. Cerebrospinal fluid showed elevated protein levels. An audiology evaluation had normal results, and brain magnetic resonance imaging could not be performed because of retained metal fragments from a prior injury.