Age-Related Macular Degeneration
Age-related macular degeneration is a condition that affects the macula part of the retina. This is in the centre of the retina and is responsible for the high detail part of your vision, for instance, when you look directly at something you are using your macula. The problem is that the cells of the macula are very delicate and can become damaged and worn out as we age. When this occurs it is known as Age-related Macular Degeneration.
The main symptom of AMD is that the central part of your vision becomes distorted or blurred. It is not painful and does not cause a total loss of sight as it does not affect the peripheral part of your vision. Although it usually affects both eyes it is often found in one eye before the other. There are two types of AMD which are known as dry and wet, but this can sound misleading as it 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 notice a gradual problem with detailed tasks such as reading or writing. Stronger reading glasses can help in the earlier stages of the disease, and Low Vision Aids such as magnifiers can help if it gets worse over time. In very severe cases a blank patch may develop in the centre of your vision but not every case of dry AMD reaches that stage.
The less common and more sudden type of AMD. It occurs when the cells of the macula stop working properly and the body starts to grow new blood vessels to try and fix the problem. As they are much weaker than normal blood vessels they tend to bleed easily which actually causes more problems. This bleeding blurs or distorts your vision – straight lines may appear wavy – and can lead to scarring. The blood vessel growth can occur very quickly and 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 this time the exact cause of AMD is unknown, however, there are some factors which seem to increase the likelihood of developing the disease. These include:
- 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.
Unfortunately there is no real treatment available for dry AMD at the moment but there is ongoing research being undertaken particularly in the use of certain vitamins and minerals. Bearing that in mind, there are several tablets available containing these vitamins and minerals. This research is ongoing and as yet the results are unclear, but from what has been discovered so far, the vitamins and minerals do not seem to improve the damage caused by the dry AMD, but they may prevent it progressing further.
Wet AMD is currently treated with a drug called Lucentis. This is injected into your eye and it stops the blood vessels growing and so prevents the bleeding. This treatment has a good success rate and prevents the disease from progressing. There also may be an improvement in your vision. Injections are usually given over a 3 month period and then each individual is reviewed. Some people may require further injections and some may stop treatment at this point depending on how the eyes have responded to.
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.