What is Age Related Macular Degeneration (AMD)?
The macula is the central part of the light-sensitive retina at the back of the eye (see ‘How the Eye Works’). When you look directly at an object, you are using the macula to discern the fine detail. The macula also allows you to see colour.
Unfortunately as we go through life the macula is particularly susceptible to age related degenerative changes and these can cause the delicate cells of the macula to stop working. People with AMD therefore have problems seeing central detail such as print in a book but because the rest of the retina still works normally they are able to see objects around them.
There are principally two types of AMD known as ‘wet’ and ‘dry’. The majority of AMD is of the dry type.
In dry AMD the cells of the macula are damaged over a long period of time and people tend to experience a gradual loss of central vision.
In wet AMD, as the cells of the macula degenerate they allow new small blood vessels to grow underneath the retina. These new blood vessels are very delicate and are prone to leak or rupture. This allows blood or fluid to collect under the macula and this can cause a rapid and severe decline in central vision. People with ‘wet’ AMD usually start with signs of only ‘dry’ AMD but as the disease progresses signs of ‘wet’ AMD develop.
AMD usually affects both eyes, although one eye may be affected long before the other.
What causes AMD?
Although there is a great deal of research into AMD going on around the world, the exact cause of AMD is still unknown but the following factors are known to be important:
Age – unfortunately as the name suggests, growing older makes AMD much more likely.
Gender – women seem more likely to develop AMD than men.
Genetics – your genes appear to have some influence on whether you develop AMD but at the moment this is not fully understood.
Smoking – smoking has been linked to the development of AMD. Studies have also shown that stopping smoking can help to prevent AMD
Sunlight – some research suggests that long-term exposure to sunlight may affect the retina. It is a good idea to wear sunglasses.
Nutrition – research suggests that some minerals and vitamins can help to protect against AMD.
How would I know if I have AMD?
Most people with dry AMD simply become aware that they are struggling more to see detail such as small print although sometimes people see a dark, blurred or blank spot in their central vision. When wet AMD is developing, people often notice that straight lines, such as door frames and windows, look wavy or distorted. This will often come on quickly, perhaps over a few hours or overnight.
Your optometrist, when carrying out a routine eye examination, will be able to see signs of AMD at the back of your eye. If you are concerned that you may be developing AMD, make an appointment to see your optometrist. If you feel that your vision has changed quickly or you are aware of distorted vision as described above, please seek prompt attention with your optometrist.
Can I prevent AMD?
Clearly there is nothing you can do about your age, gender or genetics. However, stopping smoking, protecting your eyes from the sun by wearing sunglasses and eating a balanced diet with plenty of dark green vegetables are all useful steps to take. Some people take specific dietary supplements in the form of tablets to help prevent AMD but current research suggests that these are only really useful for people already showing signs of AMD.
You cannot ‘wear out’ your eyes by reading or watching television, even if your vision is already affected by AMD.
Is there any treatment for AMD?
There is currently no treatment for dry AMD.
Over the years various treatments for wet AMD have come and gone with very limited success but the latest of these has been shown to be a significant breakthrough and effective in halting the progression of vision loss. The newest treatment involves a series of injections into the eye (apparently not as awful as it sounds) over a period of months or years. This treatment is now available on the NHS but must be administered in the early stages of the disease. If you think you may have wet AMD (distorted or quickly reducing vision in one eye) please seek attention promptly.