Macular degeneration is caused by damage to the macula, which is the area of the retina with the highest concentration of photoreceptor cells, and thus a key factor in eyesight. The exact cause of this damage is not well understood, but it may be related to inflammation, the accumulation of lipofuscin (a type of particle arising from cell damage), oxidative stress, and reduced autophagy (a process that eliminates dysfunctional cellular material).[1][2]
Aging is one of the most well-established and strongest risk factors for macular degeneration. Other risk factors include smoking,[3] moderate-to-heavy alcohol consumption,[4] type 2 diabetes,[5] limited physical activity,[6] and a lighter colored iris (e.g., blue vs. brown).[7]
Finally, genetics can have a significant impact on the risk of macular degeneration. Two genes (CFH and ARMS2) seem especially important, as common variations in these genes can significantly increase a person’s risk of developing the disease.[2]