30 epiretinal membranes which were removed during vitrectomy were studied. In all cases the main cell type was retinal pigment epithelium which transformed into spineshaped pigment cells, pigment and without pigment fibroblastic cells and fibroblasts. Strong dependence between histological structure of membrane and duration of retinal detachment was shown. In patients with duration of retinal detachment less than 1 month (9 eyes), different kind of cells with extracellular pigment with almost full absence of collagen was found. In term from 1 to 3 month (14 eyes) in membranes was collagen net with different types of cells in equal amount both collagen and cells.
