Retinal pigment epithelium(RPE)is a vital tissue for the maintenance of photoreceptor function and environment of outer retina, also the predominant cell type of proliferative vitreoretinopathy(PVR). It is also affected by many diseases of the retina and choroid, including diabetic retinopathy(DR), age-related macular degeneration(AMD)and retinal pigmentosa(RP). Although of neural origin, the RPE is capable of local repair, and cells may migrate and take on altered characteristics. These findings indicate that RPE-based therapy is a promising option for congenital or degenerate disease of the retina.