A two year trial of low protein, low arginine diets or vitamin B6 for patients with gyrate atrophy.

Four patients with gyrate atrophy on low protein (20-35 g/day), low arginine diets and one on vitamin B6 (300 mgm/day) have maintained their plasma ornithine concentrations in the range of 30-60% of pre-therapeutic trial levels for about two years. After two years, three of the five patients have shown no significant change in Snellen visual acuity, visual fields, final dark-adapted thresholds or full-field electroretinograms. All five patients have shown slight enlargement of areas of chorioretinal atrophy in the midperiphery. These patients continue on low protein, low arginine diets or on vitamin B6 to determine whether any reduction in the hyperornithinemia will result in stabilization of retinal function.