Age-Related Macular Degeneration Causes & Risk Factors
The causes of both non-neovascular and neovascular AMD are unknown, although known risk factors for both forms of the disease include
- advancing age,
- a family history of AMD,
- a light-colored iris,
- cigarette smoking, and, possibly,
- exposure to secondhand smoke.
In addition, high blood pressure appears to be linked to a greater risk of neovascular AMD, as are high levels of C-reactive protein (CRP), a marker of inflammation in the body. Studies also show a connection between AMD and cardiovascular disease.
Genetic research is yielding other potentially useful insights into the origins of AMD. Recent studies have linked certain genes to one's susceptibility to AMD. One gene, known as ATP-binding cassette rod (ABCR), controls the production of an important protein found in light-detecting cells of the retina.
Another gene, known as HF1, is involved in controlling the action of complement, a protein important in blood clotting and inflammation that also plays a role in the formation of drusen in AMD. Evidence suggests that multiple genes are involved, probably under the influence of some environmental trigger.