The RPE in Disease
The RPE is vital for normal visual function. Genetic defects unique to the RPE may produce retinal degenerations and disorders. Table 13-1 presents some of these conditions.
RPE cells have been found to play a role in nongenetic ophthalmic conditions as well. Defects in the pump mechanism of the RPE have been proposed as the cause of central serous chorioretinopathy. In certain pathologic conditions, RPE cells, which normally do not divide, detach from the basement membrane and become migratory. On contact with the vitreous and/or transforming growth factor β (TGF-β), these cells undergo metaplasia, acquiring myofibroblast qualities. Proliferative vitreoretinopathy (PVR) is an example of such a condition. In PVR, the metaplastic RPE cells form contractile membranes on the surface of the retina, leading to retinal detachment. PVR is the most common cause of retinal redetachment after surgery. See BCSC Section 12, Retina and Vitreous, for further discussion.
Table 13-1 RPE-Specific Gene Defects
Marmor MF, Wolfensberger TJ, eds. The Retinal Pigment Epithelium: Function and Disease. New York: Oxford University Press; 1998:103–134.
Parapuram SK, Chang B, Li L, et al. Differential effects of TGFβ and vitreous on the transformation of retinal pigment epithelial cells. Invest Ophthalmol Vis Sci. 2009;50(12):5965–5974.
Excerpted from BCSC 2020-2021 series: Section 2 - Fundamentals and Principles of Ophthalmology. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.