Gyrate Atrophy of the Choroid and Retina

Gyrate atrophy of the choroid and retina (GA) is a rare autosomal recessive chorioretinal degeneration characterized by myopia, cataract, varying degrees of night blindness, and progressive constriction of visual fields associated with chorioretinal atrophy resulting in blindness. The objectives of this protocol are threefold: 1. Document the natural history of gyrate atrophy. 2. Relate the clinical course to the gene defect to explore the genetic heterogeneity inherent in this disease. 3. Assess the clinical course and laboratory findings of the effects of an arginine-deficient diet. The study population is patients with elevated plasma ornithine and absence of ornithine-delta-aminotransferase activity. This is a natural history study, with a nested intervention study, non-randomized, with the outcome parameters being psychophysical, electrophysiological and ophthalmoscopic examination.