Ophthalmic manifestations of infantile phytanic acid storage disease.

Two patients had infantile phytanic acid storage disease. Patient 1 had nystagmus from early infancy, epicanthal folds, esotropia, and a pigmentary retinopathy. The second case had similar manifestations; however, no nystagmus was present. Both patients were hypotonic as infants, had a severe hearing impairment, and were moderately severely developmentally delayed. Serum phytanic acid levels in both cases were clearly elevated. The fundus and fluorescein angiogram showed macular and diffuse retinal pigment epithelial defects, vascular attenuation, and pigmentary dispersion. The electroretinogram demonstrated severely subnormal rod- and cone-mediated responses, with greater involvement evident for responses generated by middle and inner retinal neurons compared with responses mediated by photoreceptors. The ophthalmologist may be the first to recognize the characteristic features of this disorder. Early diagnosis may be important because this disorder may be ameliorated by dietary restriction of phytanic acid.