Photoreceptor outer segment phagocytosis attenuates oxidative stress-induced apoptosis with concomitant neuroprotectin D1 synthesis.

Photoreceptor cell (rods and cones) renewal is accompanied by intermittent shedding of the distal tips of the outer segment followed by their phagocytosis in the retinal pigment epithelial (RPE) cells. This renewal is essential for vision, and it is thought that it fosters survival of photoreceptors and of RPE cells. However, no specific survival messenger/mediators have as yet been identified.