Retinal Pigment Epithelium in Health and Disease: Maturation, Aging and Age-Related Macular Degeneration

Abstract

The retinal pigment epithelium (RPE) is a monolayer between photoreceptor and Bruch membrane/choriocapillaris. It has multiple functions in the homeostasis of the outer retina. As many other tissues, also RPE cells pass through different parts of a life cycle: from development to maturation to aging. Based on its prominent location, RPE cells are also often involved in diseases of the outer retina, e.g., age-related macular degeneration. This chapter summarizes the development and differentiation of RPE cells. It also highlights RPE cells’ ability to change its phenotype (proliferation, transformation) under appropriate conditions. Furthermore, the differences between natural aging and early signs of affected RPE in disease will be highlighted. The morphological RPE changes in more advanced stages of diseases like age-related macular degeneration include more than a dozen phenotypes, which, finally, will lead to apoptosis and atrophy.