[Ultrastructures of the glial epiretinal membrane]

Rabbit models of glial epiretinal membrane were established following the injection of activated macrophages into the vitreous. The membrane was composed of cells with glial characteristics, i.e., abundant intermediate filaments, microvilli, junctional complexes, and basement membranes. The extracellular matrix of mature membranes contained collagen fibrils 10 to 15 and 20 to 25 nm in diameter. Fusiform densities were seen adjacent to the cell membrane, and cells with indented nuclei were found in thick epiretinal membranes. These observations demonstrate that glial cells in the epiretinal membrane synthesize collagen and may have properties like myofibroblasts.