FAMILIAL INTERNAL LIMITING MEMBRANE DYSTROPHY - A NEW SHEEN RETINAL DYSTROPHY

Objective: To describe the clinicopathologic features of a previously unreported retinal dystrophy. Methods: Fourteen members of a single fa mily were examined. The medical records of 2 additional family members were reviewed. Pathologic examination was performed on 2 eyes of 1 af fected patient. Results: Five individuals were identified with a retin al dystrophy characterized by a glistening inner retinal surface throu ghout the posterior pole. Visual loss occurred in 3 affected patients in later life owing to superficial polycystic retinal edema and retina l folds. Electroretinographic testing revealed a selective diminution of the b wave. Pathologic examination revealed an abnormal internal li miting membrane with schisis cavities in the inner retina. Endothelial cell swelling, pericyte degeneration, and basement membrane thickenin g were present in retinal capillaries. Conclusions: A previously unrep orted sheen retinal dystrophy is described. Pedigree analysis suggests an autosomal dominant mode of inheritance. A primary defect in Muller cells is the suspected, but unproved, cause. No effective treatment f or the associated visual loss is known. The term familial internal lim iting membrane dystrophy is proposed to describe this condition.