Age-related macular degeneration is a condition that affects a small part of your retina known as the ‘macula’. This is the central part of the retina and responsible for your highly detailed vision; when you are looking directly at something you are using your macula. The cells of the macula are very delicate and can become damaged and worn out over time. When this occurs later in life it is known as Age-related Macular Degeneration.
AMD causes the central part of the vision to become distorted or blurred. It is not painful and doesn’t cause a total loss of sight as it does not affect the peripheral part of the vision. It usually affects both eyes, but often one eye before the other. There are two types of AMD; dry and wet. This is not the same as your eyes feeling dry, or watering too much – this all occurs at the retina on the inside of the eye.
This is the more common type and causes a gradual change in your central vision over time. People with dry AMD often experience problems with detailed tasks such as reading, writing or recognising small objects.Stronger reading glasses can help in the earlier stages of the disease, and Low Vision Aids such as magnifiers can help if it progresses further. If it becomes very advanced, a blank patch may develop in the centre of the vision but not every case of dry AMD progresses this far.
This is less common and more sudden than dry AMD. Wet AMD occurs when the cells of the macula stop working properly and the body starts to grow new blood vessels in the area to try and fix the problem. These blood vessels are much weaker than normal blood vesselsand tend to bleed easily – they actually cause more complications rather than fixing the problem. This bleeding blurs or distorts your vision – straight lines may appear wavy – and can lead to scarring.
This blood vessel growth can occur very quickly. It can be treated but only if it is identified early enough. If you experience any sudden changes in your vision, either blurring or distortion, make sure you see your Optometrist quickly. Dry AMD can change into wet AMD so if you have dry AMD be particularly aware of any sudden changes to your vision.
At the moment the exact cause of AMD is unknown. There are some factors which seem to increase the likelihood of developing the disease:
Age: AMD is age related, therefore is more likely to develop later in life.
Gender: Women seem to be more likely to develop AMD than men.
Genes: If there is a family history of AMD this may put you at an increased risk of developing the disease yourself, however not all AMD is thought to be inherited.
Smoking: Smoking greatly increases your risk of developing AMD.
Sunlight: Some studies suggest that exposure to the UV in sunlight can increase the risk of developing AMD, so wearing sunglasses to help protect the eyes is highly recommended.
Nutrition: There are ongoing studies looking at the role nutrition plays in the development of AMD, but at present the results are not clear. The recommendation at the moment is to eat a balanced diet with plenty of fruit and vegetables.
If you already have moderate or severe AMD, the AREDS study has found that taking Macu-vision tablets can reduce the chance of major sight loss by 25%. There is no evidence so far that taking these tablets will prevent you developing AMD in the first place.
At present there is no real treatment available for dry AMD. There is a lot of research being undertaken at present, particularly in the use of certain vitamins and minerals. As such, there are several tablets available containing these vitamins and minerals. This research is ongoing and as yet the results are unclear. From what has been discovered so far, the vitamins and minerals do not seem to improve the damage caused by the dry AMD, but may prevent it progressing further.
Wet AMD is currently treated with a drug called Lucentis. This drug needs to be injected into your eye and it stops the blood vessels growing, thus preventing the bleeding. This treatment has a goodsuccess rate, preventing the disease from progressing and thus preventing your sight getting worse. There may be an improvement in the vision also. Injections are usually given over a 3 month period and then each individual is reviewed; some may require further injections and some may stop treatment at this point depending on how the eyes have responded to the drug.For further information, please see the RNIB’s website, which is full of up-to-date information on a wide range of eye conditions including AMD.