Retinal Pigment Epithelium (RPE)
A very thin cell layer found directly beneath the photoreceptor cells. RPE cells bring nutrients and oxygen to the photoreceptor cells, and supplies, recycles, and detoxifies products involved with the phototransduction process.
The retinal pigment epithelium (RPE) is a very thin, pigmented cell layer found directly beneath the photoreceptor cells. RPE cells sit between the photoreceptor cell layer of the retina and the Bruch's membrane and choroid. The RPE obtains nutrients and oxygen from the choroid and provides them to the photoreceptor cells, while also carrying away waste products from photoreceptor cells for disposal to the choroid. In addition, RPE cells recycle proteins and other components involved in the phototransduction process and provide other survival proteins to the retina. RPE cells phagocytose or "chew up" the ends of photoreceptor outer segments every day as a "preemptive strike" to prevent damage from built-up waste products.