Electron microscopy studies of the trabecular meshwork in pigmentary glaucoma

Trabeculectomy specimens from three patients with pigmentary glaucoma were investigated electron-microscopically. The pigment accumulations were highest in the uveal and inner corneoscleral trabecular meshwork. The outer lamellae and the cribriform region were hypochromic, while the endothelium of Schlemm's canal was unpigmented. The aqueous pathways of the inner trabecular meshwork were obstructed by hyperpigmented cells, cellular fragments and released pigment granules, those of the outer trabecular meshwork by depositions of extracellular material and collagen, by degenerative cells and by collapse of the trabecular lamellae.