EARLY-ONSET POSTERIOR POLYMORPHOUS DYSTROPHY

We report an unusual case of posterior polymorphous dystrophy in which corneal failure began within a few weeks of birth. Histopathologic fi ndings included the presence of abnormal corneal endothelial cells wit h many microvilli on the surface. Descemet membrane was severely atten uated, and there was a thick posterior collagenous layer consisting of numerous fibroblastlike cells in a fibrillar extracellular matrix; ul trastructural immunocytochemistry showed this to contain tenascin, fib ronectin, and collagen type I. Few histopathologic data on this diseas e at such an early age have been available, and to our knowledge, the composition of Descemet membrane has not been examined before. The mic rovilli-covered cells are shown to be present from the outset of the d isease, not just in long-standing cases as in previous reports; change s in Descemet membrane may influence disease evolution.