Induction of proliferative vitreoretinopathy by human retinal pigment epithelial cells

Proliferative vitreoretinopathy (PVR) is characterized by the formation of fibrocellular membranes in the vitreous and on the surfaces of the retina. These membranes exert tractional forces on the retina, causing retinal tears and/or detachments. The purpose of this study is to develop a reproducible animal model that closely mimics PVR in the clinical setting. The retinal pigment epithelial (RPE) cell is the major cell type found in PVR membranes. We cultured RPE cells from a human epiretinal membrane (ERM) obtained at surgery from a patient with PVR, and injected them into the right eye of 24 albino rabbits. The eyes were examined by indirect ophthalmoscopy over 4 weeks. By day 7, all but one of the 24 eyes developed proliferative vitreoretinopathy, with 8 progressing to localized tractional retinal detachment (TRD). By day 21,17 out of the 24 eyes had developed localized TRD. One eye went on to develop an extensive TRD by day 28. Immunostaining showed that mostly RPE cells, but also myofibroblasts, glial cells, and collagen were present in the newly formed rabbit PVR membranes. Thus, human RPE cells cultured from a human PVR membrane appear to be capable of inducing PVR in rabbits. The resultant epiretinal membranes are similar to those formed in human PVR, and consist mainly of RPE cells.