Schnyder's crystalline corneal dystrophy in association with hyperlipoproteinemia: histopathological and ultrastructural findings.

A 61-year-old man with Schnyder's crystalline corneal dystrophy showed a slight reduction in vision during 16 years of observation. Plasma lipoprotein analysis done 10 years after presentation showed type IIA hyperlipoproteinemia, which was also detected in one of four siblings examined, none of whom showed the characteristic corneal dystrophy. Electron microscopic studies on corneal biopsy specimens from the patient showed abundant crystalline material and vacuoles predominantly in the superficial corneal stroma, with occasional keratocytes and rare basal epithelial cells containing laminated structures. The findings of a focal continuity between the trilaminar membrane around some of the stromal vacuoles and the plasmalemma of the keratocytes as well as dissolution of the plasmalemma in other keratocytes are consistent with the hypothesis of a local cellular role in the development of this corneal disorder.