HYALINE RIDGES ON THE POSTERIOR CORNEA*t BY

HYALINE or glassy ridge formation on the posterior corneal surface appears to be a not uncommon phenomenon, the recognition of which may be missed without careful examina-tion with the slit-lamp microscope. Normally, Descemet's membrane is secreted as a hyaline tissue by the endothelial corneal cells during intra-uterine life; the exact point of development at which it appears is not definitely known, but may be at the 49 mm. stage (Mann, 1964). In some pathological conditions, these endothelial cells may exhibit exuberant hyaline formation, so that elevated plaques or ridges may form on the posterior corneal surface. Elsewhere in the eye, similar abnormal hyaline formation has long been recognized as occurring in circumstances of chronic irritation affecting ocular cellular layers, such as the lens and retinal epithelium and iris endothelium, and in such conditions as simple glaucoma and chronic iridocyclitis (Herbert, 1927). Hyaline ridges or membranes on the cornea are of two kinds: the first and more common is closely applied to the cornea throughout its extent and the second lies mainly in the anterior chamber but is attached to the cornea at one or more extremities. The thre