An eye disease that results in a loss of central vision leaving only side or peripheral vision intact. Age-related Macular Degeneration (AMD) is the leading cause of vision loss in older people. Macular degeneration affecting younger people is called Juvenile Macular Dystrophy and can run in families. Read More About Macular Conditions.
There are two types of AMD, dry and wet and both can lead to severe vision loss. AMD affects the macula, the small central part of the retina responsible for central and detailed vision. It is not painful but cells in the macula break down causing this loss of central vision.
Dry AMD – This is the most common form of the disease, affecting about 90% of those with AMD. It has a more gradual onset and generally occurs when the waste products are not carried away from the macula as effectively resulting in a collection of yellow fatty deposits called drusen. This gradual deterioration of the macula usually occurs over many years and vision changes are much more subtle.
Wet AMD – This is much less common and occurs when tiny new abnormal blood vessels begin to grow in or under the retina.. These then leak blood and fluid which damages the macula. Wet AMD results in a more severe and sudden loss of central vision.
Signs of AMD
As the cells in the macular deteriorate the ability to see clearly will change. Objects directly in front may appear to change shape, size or colour. Vision may become blurry, lines become distorted or dark spots may appear in the centre of the image. The central part of the retina, which is responsible for detail, colour and daylight vision is damaged. Reading can become difficult and colour vision reduced and there may be a need for increased light.
Risk factors for AMD
These include age, high cholesterol and high fat diets, untreated high blood pressure and smoking, all of which can result in poor circulation to the retina. A lack of certain nutrients needed by the retina can increase the risk and can be helped by eating a balanced diet rich in fruit and green leafy vegetables. Excessive sunlight and harmful UV light is also a risk factor and can be helped by wearing good sunglasses. Some families have a history and greater tendency for the condition and women are also more likely to develop AMD than men.
Using the Amsler grid you can test yourself to check for any distortions or abnormalities in your vision.
How to use the Amsler Grid
- Hold the grid at normal reading distance using your reading glasses if you have them.
- Cover one eye and look at the black dot in the centre.
- Whilst looking at this central spot see if all the lines appear straight and even. Check that none are wavy, distorted or missing.
- Then cover your other eye and repeat.
- If you notice any abnormalities in your vision consult your optician or ophthalmologist straight away.
This test can give an indication but is not a substitute for a full eye examination which you should have to check your vision at least every 2 years.