Natures Protective Entity: Macular Pigment

The Photoreceptor System

macular pigment layers

  • The photoreceptor system and the underlying RPE layer is protected by the yellow Macular Pigment (MP), and MP is entirely of dietary origin and composed of the carotenoids – lutein (L), zeaxanthin(Z) and meso-zeazanthin (MZ).
  • MP is located at a prereceptoral level (i.e. before the light is incident upon the photoreceptors), and therefore protects the photoreceptors and the RPE from photo-oxidative damage (especially given that lipofuscin is a chromophore; a chromophore refers to a compound that produces damaging free radicals when exposed to blue light).
  • Moreover, MP’s constituent carotenoids are powerful antioxidants (i.e. can neutralise damaging free radicals), and therefore limit injury caused by photo-oxidative processes.
  • The epicenter of the macula, an area known as the fovea, has the highest concentration of cone photoreceptors.
  • Accordingly, the fovea is responsible for sharp central vision and for color vision, and is essential for a good quality of life and for safety.
  • At the fovea, MZ is the dominant carotenoid.