Refsum's disease: electron microscopy of an iris biopsy.

Refsum's disease (phytanic acid storage disease) results in an accumulation of lipid as a result of an absence of mitochondrial hydroxylation of phytanic acid. We describe a previously unrecorded electron microscopic study of lipid deposition in the iris pigment epithelium of a patient with Refsum's disease, and lipid was present in other sites within the iris.