Early-onset posterior polymorphous dystrophy
S. G. Levy, J. Moss, B. A. Noble and A. C. McCartney
Department of Histopathology, Charing Cross Hospital Medical School, England.
We report an unusual case of posterior polymorphous dystrophy in which
corneal failure began within a few weeks of birth. Histopathologic findings
included the presence of abnormal corneal endothelial cells with many
microvilli on the surface. Descemet membrane was severely attenuated, and
there was a thick posterior collagenous layer consisting of numerous
fibroblast-like cells in a fibrillar extracellular matrix; ultrastructural
immunocytochemistry showed this to contain tenascin, fibronectin, and
collagen type I. Few histopathologic data on this disease at such an early
age have been available, and to our knowledge, the composition of Descemet
membrane has not been examined before. The microvilli-covered cells are
shown to be present from the outset of the disease, not just in
long-standing cases as in previous reports; changes in Descemet membrane
may influence disease evolution.
