Talc retinopathy in primates: a model of ischemic retinopathy. III. An electron microscopic study.

Electron microscopic study of experimental talc retinopathy provides an opportunity to study the basic cytologic response of retinal and choroidal vessels to small, relatively inert emboli. Occlusion of the retinal and choroidal capillaries resulted primarily from the cellular reaction to, rather than directly from, the emboli. Mitotic figures in pericytes were observed. Even though we failed to produce retinal neovascularization (as is sometimes seen in human talc retinopathy) in this experimental model, our observations suggest that proliferation of pericytes may be an initial step in the process of retinal neovascularization.