CELL ATTACHMENT TO, AND CONTRACTION OF, THE RETINA IN-VITRO

Purpose. To examine the behavior of fibroblasts and retinal pigment ep ithelial cells after attachment to the retinal surface in vitro to elu cidate the pathobiology of the early stages of epiretinal membrane for mation. Methods. Human retinal pigment epithelial (HRPE) cells and bov ine Tenon's capsule fibroblasts (BTFs) were seeded onto the surface of bovine retinal explants maintained in organ culture. The changes indu ced in the underlying retina, including contraction, were assessed dur ing a period of up to 10 days. Immunohistochemistry was used to assess proliferation of the seeded cells and to determine deposition of extr acellular matrix. Results. Explants of bovine neuroretina were maintai ned in organ culture, with brood morphologic preservation of the inner limiting lamina and inner retinal layers, for 7 to 10 days. The HRPE cells and the BTFs attached to the retinal surface and exerted tractio nal forces, producing partial-and full-thickness retinal folding. Cont raction commenced within 24 hours of attachment of the cells and conti nued for several days, with most of the contraction occurring within t he next 48 to 72 hours. The HRPE cells and BTFs were found to be equal ly contractile, Deposition of cellular fibronectin (but not collagen t ype I) was demonstrated. Conclusions. The contractile cellular membran es generated in this organ culture system exhibit many of the morpholo gic and functional features of epiretinal membranes found in the early stages of proliferative vitreoretinopathy.