Damaging Effects of Metabolism: Photoreceptor Cells photoreceptor cell diagram

  • Photo-oxidative damage of the photoreceptor cells is ongoing and relentless, and they are therefore necessarily and continuously renewed.
  • There is a single layer of cells behind the retina (known as retinal pigmented epithelium, or RPE) which nurtures the photoreceptors and removes waste products from the photoreceptors.
  • One of these waste products from photo-oxidative damage of photoreceptors is known as lipofuscin (a yellow age pigment) and this accumulates with the passage of time in the RPE cells, compromising the ability of these cells to function optimally or at all.
  • With age, lipofuscin fills the RPE cells. Eventually, RPE cells may give out and extrude their contents which are then clinically seen as drusen, a hallmark of dry AMD (Age Related Macular Degeneration).