Ocular findings in primary hyperoxaluria.

Primary hyperoxaluria (primary oxalosis) is a rare autosomal recessive inborn error of glyoxylate metabolism that causes widespread calcium oxalate crystal deposition in diverse tissues. Because others have reported only occasional ocular involvement, we reviewed the ophthalmologic findings in our 24 patients with primary hyperoxaluria to document its funduscopic variability and to determine its visual prognosis and its possible systemic significance. Eight (30%) of our 24 patients with primary hyperoxaluria exhibited a bilaterally symmetrical retinopathy. The abnormalities were predominantly confined to the posterior pole and ranged from many small (100- to 200-microns) subretinal black ringlets to single large (2- to 3-disc diameter) geographic lesions. In 3 of the 8 patients with oxalate retinopathy, diffuse optic disc pallor was evident. Five patients with both normal-appearing optic discs and oxalate retinopathy had relatively good visual acuities. The maculopathy of primary hyperoxaluria caused mild visual impairment while optic nerve dysfunction associated with this disease appeared to be much visually debilitating. Also, the presence of oxalate maculopathy was associated with a more severe systemic course for the disease.