Ocular findings in patients with gyrate atrophy on pyridoxine and low-protein, low-arginine diets

Abstract

Five patients, ages 12 to 30, with gyrate atrophy have shown substantial (60% or greater) decreases in plasma ornithine concentrations within four to eight weeks when placed on a therapeutic trial of low-protein (10-15 g/day), low-arginine diets supplemented with essential amino acids (EAA) and pyridoxine hydrochloride. Four of five patients have continued on modified protein restriction (20-35 g/day) and one on pyridoxine (300 mg/day) alone with maintenance of plasma ornithine in the range of 30 to 60% below pretherapeutic trial levels. After one year, four of five patients have shown no significant improvement in visual acuity, fields, final dark-adapted thresholds, electroretinograms, or fundus appearance. One patient with the poorest control of plasma ornithine has developed a decrease in ERG amplitudes and a new area of chorioretinal atrophy. These patients continue in this trial to determine whether or not any reductions in hyperornithinemia will modify the course of the ocular disease.