Human massive periretinal proliferation. In vitro characteristics of cellular components.

The sources of cellular constituents of fibrous and cellophane membranes formed in massive periretinal proliferation have been unclear. We successfully obtained cellular outgrowths from abnormal vitreous specimens collected at surgery for massive periretinal proliferation in 13 patients, using standard culture techniques. By phase-contrast and ultrastructural morphological criteria, we identified four major cellular constituents: (1) macrophages present in all specimens: (2) pigmented epithelioid cells, present in a majority of specimens; (3) glial-like cells, present in a majority of specimens; and (4) fibroblastic cells, present in all specimens but much more prominent in grossly fibrous tissues. Our findings confirm published reports of pigmented epithelioid cells and glial-like cells in fixed surgical specimens and advance our understanding of the heterogeneity of pathologic cells active in producing this serious complication of retinal reattachment surgery.