Stargardt Disease.

Stargardt disease (STGD) is one of the most common macular dystrophies in young adults. It progresses slowly. Its prevalence is about 1:8000-10,000. Age of onset is a surrogate marker: The earlier the onset, the more severe the disease course. Onset usually occurs in childhood or early adolescence, at about 10-15 years of age. Vision is between about 20/70 and 20/200. The fundus shows a bull's eye pattern or beaten-bronze appearance, with or without yellowish flecks (fundus flavimaculatus). Fluorescein angiography may show dark choroid in about 80% of cases. On fundus autofluorescence (FAF), newer flecks appear hyperautofluorescent (hyperAF); older ones become progressively more hypoAF with time. Some flecks are surrounded by a ring of decreased AF. Peripapillary sparing is one the characteristics of Stargardt disease, but this area can be involved in about 2-7% of cases. The reason for this sparing is unclear; this area may be more resilient to the deleterious effect of ABCA4 gene mutation, and there might be a more favorable RPE photoreceptor ratio, resulting in less lipofuscin build-up, in the presence of a thicker overlying peripapillary retinal nerve fiber layer. Patients with Stargardt disease should avoid bright light and excessive vitamin A.