Schlemm's canal and the trabecular meshwork. An electron microscopic study of the normal structure in man and monkey (Cercopithecus ethiops)

Abstract

Schlemm's canal and the trabecular meshwork of eight human and eleven monkey eyes have been analyzed by means of electron microscopy. 1. The size, shape and delineation of the lumen of Schlemm's canal is given. 2. The wall of Schlemm's canal in a strict sense is a single endothelial layer. Through some of the cells there is a small channel, which connects the intertrabecular spaces with Schlemm's canal. The details of the endothelium is discussed. 3. The wall in a broader sense is a 4–8 μ thick layer of endothelial cells, collagen material, homogeneous material and “empty” spaces. 4. The first trabecular sheet has a very intimate relationship to the wall. 5. The topography of the trabecular sheets is discussed. Data about the size of the sheets are given. The increasing thickness with age is especially stressed. The composition of the individual sheet has been evaluated and change in composition with age is noted. 6. The topography, size and interconnections of the intertrabecular spaces are discussed. There exist open communications through the trabecular meshwork which connect the anterior chamber with Schlemm's canal. 7. Nerves are present in different parts of the trabecular meshwork, even in immediate vicinity of the inner wall of Schlemm's canal. There are suggestions that some of the nerves are adrenergic. 8. Besides red and white blood cells there are found plasma cells and mast cells in the trabecular meshwork. 9. The difference in appearance of the trabecular meshwork between human and monkey eyes is noted. 10. To a limited extent the structure of the trabecular meshwork is discussed with regard to the function.