What is the primary role of the retinal pigment epithelium?

The primary role of the retinal pigment epithelium (RPE) is to nourish the retinal visual cells, which are the photoreceptors located in the outer layer of the retina. The RPE plays a critical role in supporting the health and function of these photoreceptors by providing essential nutrients, facilitating the recycling of visual pigments, and maintaining the integrity of the blood-retina barrier. By doing so, it helps to ensure optimal visual function and protects these sensitive cells from damage.

In addition to nourishment, the RPE also has functions such as phagocytosis of shed photoreceptor outer segments and the absorption of excess light, but its primary function is closely linked to the nourishment and maintenance of retinal cells. This is pivotal for overall vision quality, as damaged or poorly nourished photoreceptors can lead to serious conditions such as macular degeneration.