Induction of proliferative vitreoretinopathy by a unique line of human retinal pigment epithelial cells

Background: The most widely used models of proliferative vitreoretinopathy (PVR) rely on injection of cells into the vitreous of animals. Using retinal pigment epithelial (RPE) cells from human PVR membranes may produce a more accurate model of human PVR. We performed a study to determine whether human RPE cells derived from a single epiretinal membrane (ERM) are capable of inducing the same disease in the rabbit eye, and whether the induced ERMs had cellular components similar to those of human PVR membranes. Methods: Cells were harvested from a human ERM obtained at surgery for PVR. RPE cells were cultured from the membrane and injected into the right eye of 24 New Zealand albino rabbits. The left eyes served as controls. The eyes were examined by indirect ophthalmoscopy over 4 weeks. The enucleated eyes were then examined by means of microscopy and histochemical analysis. Results: By day 7, PVR had developed in all but I of the 24 experimental eyes, with 8 progressing to localized tractional retinal detachment. By day 21, localized tractional retinal detachment had developed in 17 eyes; I eye progressed to extensive tractional retinal detachment 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. Interpretation: Human RPE cells cultured from a PVR membrane appear to be capable of inducing PVR in rabbits. The resultant ERMs are similar to those formed in human PVR and consist mainly of RPE cells.