1. Light Absorption: The melanin in RPE cells absorbs excess light that passes through the retina, reducing phototoxicity and enhancing visual acuity. 2. Phagocytosis: RPE cells phagocytose and digest the shed outer segments of photoreceptors, a process crucial for photoreceptor renewal and function. 3. Nutrient Transport: The RPE facilitates the transport of nutrients, ions, and metabolic waste products between the retina and the choroid. 4. Secretion: RPE cells secrete a variety of growth factors and cytokines that maintain the structural integrity of the retina and promote photoreceptor survival. 5. Blood-Retina Barrier: The tight junctions between RPE cells form a selective barrier that regulates the movement of substances between the retina and the blood, helping to protect the neural retina from systemic fluctuations.
