Age Related Macular Degeneration (AMD) is the leading cause of blindness in the industrialised world. A slow and progressive condition affecting more than 600,000 in the UK, AMD attacks the eye’s macula, the small central part of the retina that allows us to see fine detail.
AMD occurs when the cells in the macula break down, causing loss of sight in the central part of the field of vision, but leaving peripheral vision intact. In most cases, AMD is a slow, progressive and painless condition, which affects both eyes, usually one after the other. It may take up to 10 years from initial diagnosis before sufferers notice any loss of vision, but, even though breakdown of macula cells may not begin until the age of 60 or 70, long-term awareness and preventative measures should begin much earlier in life.
There are two forms of AMD: “Dry” AMD and “Wet” AMD. The difference between the two is that in the more common Dry AMD, loss of vision occurs when small yellowish deposits called ”drusen” begin to accumulate beneath the macula, breaking down the light-sensing cells. Wet AMD is less common, and loss of vision occurs when abnormal blood vessels begin to grow behind the retina.
Research has identified a number of risk factors, which may predispose a person to suffer from AMD. The most obvious and highest risk factor is age, but others include:
- • eating a diet low in antioxidants
- • cell damage from exposure to sunlight
- • smoking
- • heredity
- • being female
- • heart disease, which means blood flow to the eye is poor
Despite identifying key risk factors, nobody is yet certain of the exact cause of AMD, meaning treatment options are limited. A small percentage of cases in the early stages of Wet AMD may be helped temporarily by treatment with lasers, which, when focused on the retina, destroy the new blood vessels growing beneath it. This is not a permanent solution, and there is no evidence that this form of treatment is effective in treating Dry AMD.
Although treatment options are limited, there are preventative measures that can be taken. A growing body of research suggests that nutrition plays a key role in AMD, and that eating a diet rich in a certain group of antioxidants and carotenoids may help lower the risk of developing AMD and slow the progress of the disease. In particular, the carotenoids lutein and zeaxanthin have been identified by researchers, and it is thought that their yellowish pigment helps to block the harmful blue light from reaching the retina.
Lutein and zeaxanthin can be found in leafy green vegetables such as spinach and kale, but if it isn’t possible to get adequate nutrients directly from vegetables, nutritional supplements can help provide the recommended daily lutein dose of 6mg.