OCULAR MANIFESTATIONS OF METABOLIC DISORDERS

Papers published between October 1990 and September 1991 on the ocular manifestations of metabolic diseases are reviewed. In this period, the correlation and heterogeneity of the clinical features of albinism in 13 members of a family were presented. Linkage studies in a six-generation family with Aland eye disease have assigned the gene locus to Xq22. The phenotypic variability of the clinical findings in one familv was discussed. Misrouting of the visual pathwavs was found to be specific for albinism and absent in congenital nystagmus in a comparative study, based on visual evoked potential. The pattern of hypopigmentation of the fundus in six carriers of X-linked ocular albinism was presented with a provocative discussion of its explanation. An extensive linkage analysis of oculocutaneous albinism in 47 South African black families was begun. The first ocular histopathologic study of a vitamin B6-responsive gyrate atrophy patient was reported. The ocular findings and symptoms in nephropathic cystinosis showed evidence of clinical variability. The ocular tissue obtained at autopsy from a patient with type 1 primary hyperoxaluria revealed oxalate deposits in the outer plexiform and nuclear layers. The clinical findings of a family with autosomal dominant crystalline dystrophy were presented; transmission electron microscopy of circulating lymphocytes demonstrated crystals and an unknown amorphous material, findings thought to be similar to those seen in cholesterol ester storage disease. Unesterified cholesterol deposits have all extracellular localization in Schnyder's corneal crystalline dystrophy. A mutation responsible for the fish eye disease has been identified in the lecithin-cholesterol acyltransferase gene in two affected brothers. Kayser-Fleischer ring is an especially important clinical finding in the neurologic form of Wilson's disease. Occasionally, it may be seen as a sign in other forms of liver disease. Strabismus and retinitis pigmentosa are frequently found in the disialotransferrin developmental deficiency syndrome. The first histopathologic report of a case of late-infantile galactosialidosis showed diminished numbers of swollen ganglion cells with abnormal deposits throughout the retina. Mucopolysaccharide deposition in the trabecular meshwork may be responsible for the development of glaucoma in older patients with Morquio syndrome. The ocular findings of Fabry's disease in affected male patients and carrier female patients without angiokeratosis were reported. Type IV amyloidotic polyneuropathy (Meretoja syndrome), a dominant disorder, has ocular manifestations that include lattice corneal dystrophy, open-angle glaucoma, blepharochalasis, and cranial nerve neuropathy. The discovery of light-fixed pupils led to the first antemortem diagnosis of neuronal intranuclear hyaline inclusion disease. Electroretinography confirmed central nervous system dysfunction.