Mild retinal changes in a 47-year-old patient with phytanic acid storage disease.

A 47-year-old man complained of poor near vision. He had chronic polyneuropathy, bilateral shortening of the proximal phalanges, and ichthyosis. His serum phytanic acid level was merkedly elevated. The fundus and fluorescein angiograms showed diffuse fine granular changes throughout the retina. However, no pigmentary retinal degeneration, vessel attenuation, or disk atrophy was found. The visual field and dark adaptation results were normal. The electroretinogram demonstrated mildly subnormal rod responses with normal implicit times and cone responses within the normal range. The S-cone electroretinogram showed decreased amplitude and normal implicit time. These ophthalmological findings were not consistent with classical retinitis pigmentosa. We believe that this patient may have an uncommon type of adult Refsum's disease.