Proliferative vitreoretinopathy. Histopathology of retroretinal membranes

Light- and electron-microscopic studies of 43 eyes with retroretinal membranes are presented. Associated features were severe blunt or penetrating injury, total retinal detachment, surbretinal proteinaceous exudate, and concomitant presence of preretinal fibrocellular or fibrovascular proliferations. The retinal pigment epithelium was found to be the major cellular component in early (as soon as 1 week) and chronic retinal detachment cases. Isolated glial-derived membranes were less common and were found in cases with chronic retinal detachment. Macrophages and fibrocytes, along with the retinal pigment epithelium and glia, were detected in mixed membranes. Subretinal proteins are thought to influence migration and attachment of the retinal pigment epithelium, which in turn provides a template for proliferation of the various cell types described.