The pigment epithelium of the monkey. Topographic study by scanning and transmission electron microscopy.

The pigment epithelium of the normal monkey was studied by scanning and transmission electron microscopy. Appearance of microvilli of the cell are demonstrated and compared topographically. The apical surface of the pigment epithelium consists of densely distributed fine microvilli. No thick portion of the villi or the cell borders are seen in normal conditions. The attachment of the epithelium and the outer segment is extremely firm and breakage of the microvilli or outer segments occurs easily in the attempt to separate these two layers.