The corneal endothelium and Descemet's membrane in the iridocorneal endothelial syndrome.

A 39-year-old woman with progressive left unilateral glaucoma associated with corneal edema, iris changes, and peripheral anterior synechia formation underwent a left trabeculectomy and iridectomy in an attempt to control the intraocular pressure. Shortly after surgery the edema worsened despite low intraocular pressure measurements. A repeat trabeculectomy combined with a full thickness keratoplasty was performed 11/2 years later. The posterior corneal surface was found to be covered by a partially doubled layer of endothelial cells with ultrastructural features resembling epithelium. Similar cells were not noted on the surface of the initial trabecular meshwork and iris specimens, but were seen on the surface of the specimens obtained at the second trabeculectomy. The anterior and middle portions of Descemet's membrane, formed during perinatal and early adult life, appeared normal, but its posterior portion appeared abnormal. The ultrastructural changes in the endothelial cells and the abnormalities observed in Descemet's membrane suggest that the endothelial cells were initially normal but subsequently acquired epithelial-like features as they degenerated and proliferated. The continued presence of corneal edema despite the hypercellularity of the endothelium suggests that the proliferating cells were permeable to aqueous.