Ocular findings in primary hyperoxaluria
K. W. Small, R. Letson and J. Scheinman
Department of Neurology, Duke University, Durham, NC.
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.
