Congenital hereditary (juvenile X-linked) retinoschisis. Histopathologic and ultrastructural findings in three eyes.

One surgically enucleated and two postmortem eyes were obtained from two related men with congenital hereditary retinoschisis. A periodic acid-Schiff-positive amorphous material was identified within the retina adjacent to the schisis cavities. Ultrastructural examination of this material showed numerous extracellular filaments, measuring approximately 11 nm in diameter. Similar filaments were found in the vitreous in all three globes and in a normal globe. We believe that the intraretinal filaments are produced by defective Müller cells and that their extracellular accumulation may lead to degeneration of cells and subsequent schisis formation.