Scanning electron microscopic studies on the development of the iridocorneal angle in human eyes.

The structural changes occurring in the iridocorneal angle of human eyes from fetuses, premature and mature infants, and adults were studied with light and electron microscopy. The scanning election microscopic technique with the use of freeze-dried tissue pieces provided much new information. The iridocorneal angle is covered by a continuous monolayer of polyhedronal endothelial cells up to about eight months gestation age. The uveal meshivork consists of two parts, each of which has its own characteristic structure. The endothelial cells in the iridocorneal angle change their shape and become separated by holes of varying sizes. They are observed to be arranged as sheaths in several layers. The trabeculae in the adult eye are covered with multipolar endothelial cells arranged in several layers. The lamellar structure of the corneoscleral trabeculae is observed readily on scanning electron micrographs. The results obtained are discussed in relation to previous studies on the iridocorneal angle with light and transmission electron microscopy. The possible role of a persisting continuous endothelial membrane in the iridocorneal angle for the pathogenesis of congenital galucoma is stressed..