Mr Nicholas Glover - AMD
Mr Nicholas Glover  - Consultant Cataract & Vitreoretinal Surgeon

Age related macular degeneration 

Age-related macular degeneration (AMD) is an eye condition that causes problems with your central vision, but does not lead to total loss of sight. AMD may make this central vision distorted or blurry and, over a period of time, it may cause a blank patch in the centre of your vision.   

Causes 

 The exact cause for AMD is not known. Some things are thought to increase your chances of developing AMD:   

 •  Age: AMD normally develops in people over the age of 65, although it can develop in people in their forties and fifties   

 •  Gender: more women have AMD than men, probably because women tend to live longer.    

 •  Genes: some genes have been identified which seem to be linked to the development of AMD   

 •  Smoking: smoking greatly increases risk and severity of AMD.   

 •  Sunlight:  studies suggest that exposure to high levels of sunlight (particularly the UV light) throughout your life may increase your risk of developing AMD.   

 •  What you eat: There is some evidence that vitamins A, C and E and zinc may help to slow the progression of AMD.    

 Although you cannot change your age or genes, current thinking is that protecting your eyes from the sun, eating a balanced diet with plenty of fresh fruit and vegetables, and stopping smoking may all help reduce the risk of AMD.   

 Unfortunately, because the exact cause of AMD is not known you may develop this condition even if you don't have any of these risk factors.   

Symptoms 

 The first problems people notice are with their ability to see detail. You may have problems reading small print, even if you wear your usual reading glasses, or you may find that there is a slight smudge in your central vision. Straight lines may look distorted or wavy. You may also find you become sensitive to bright light or that you see shapes and lights that aren't actually there.   

 You should have your eyes tested by an optometrist (optician) if:   

 •   you notice difficulty with reading small print with reading glasses   

 •   straight lines start to look wavy or distorted   

 •   your vision isn't as clear as it used to be.   

The Macula   

 The macula is a tiny area of your retina which is very important for seeing detail, colour and things directly in front of you.  

Types of AMD 

 There are two main types of AMD - "wet" AMD and "dry" AMD.   They are called "wet" and "dry" because of what the ophthalmologist sees when examining the inside of your eye, not because of how the eye feels or whether you have a watery or dry eye.   

Dry AMD   

 Dry AMD is the more common type of AMD. It usually develops very slowly and causes a gradual change in your central vision. Dry AMD takes a long time to develop, often a number of years . At its worst, dry AMD causes a blank patch in the centre of your vision in both of your eyes. But it doesn't affect your peripheral vision, so never leads to total blindness.    

Wet AMD   

 About 10-15 per cent of people develop wet AMD. You develop wet AMD when the cells of the macula stop working correctly and the eye starts growing new blood vessels to fix the problem. Unfortunately, these blood vessels grow in the wrong place and cause swelling and bleeding underneath the macula, causing damage to your macula and eventually leads to scarring.   The damage to your central vision causes a blank patch in the centre of your sight.   

 Wet AMD can develop very quickly, making serious changes to your central vision in a short period of time.   

 Treatment is now available for wet AMD, which stops the new blood vessels from growing and damaging your macula. This treatment usually needs to be given quickly, before too much damage occurs to your macula. If the blood vessels are left to grow, the scarring and the sight loss it causes becomes permanent. Wet AMD doesn't affect your peripheral vision, so it doesn't lead to total blindness.   

Both types of AMD   

 Wet and dry AMD have things in common. They usually affect both your eyes, though sometimes one eye may be affected long before the other. Both wet and dry AMD only affect your central vision and won't affect your vision around the edge of your sight. So neither type of AMD will cause you to lose all your sight.   

 Some people diagnosed with dry AMD find that, with time, new blood vessels grow and they develop wet AMD. If you have dry AMD and your sight suddenly changes you should always have this checked by your ophthalmologist   

 Some people may have wet AMD in one eye and have dry AMD in the other which doesn't develop into wet AMD. Most people, however, have the same type of AMD in both eyes. 

 Confusingly, people who have had wet AMD for a long time, causing bad scarring on their retina, may be told that their wet AMD has "dried up". This means that new blood vessels have regressed. At this stage of wet AMD, the treatments available wouldn't help.   

 AMD is not painful and it never leads to a complete loss of vision. Most people with AMD keep their peripheral vision (everything around the edge). This peripheral vision will mean that you should still be able to get around on your own..   

Changes in your vision 

 If you notice a sudden change in your vision, you should always have your eyes examined by an eye health professional. However, if your sight changes very quickly then you can attend the accident and emergency department at your nearest hospital, where an ophthalmologist will be able to check your eyes. 

 If you have slight changes in your vision then you should arrange for an eye examination with an optometrist (optician). They are trained to detect AMD and, if necessary, can refer you to your local ophthalmologist. 

 If you have dry AMD and you notice a sudden change in either of your eyes you should let the hospital know. This is because dry type AMD can develop into wet AMD and if this happens sight saving treatment may be possible. 

Hospital eye examination 

Sometimes the ophthalmologist can tell you whether they think you have AMD or not from this examination. However, you may need a test called a Fluorescein angiogram or an OCT to find out for certain whether you have wet or dry AMD.   

Treatment 

 A number of treatments are available for wet AMD. These mainly work by stopping the growth of new blood vessels. This means that treatments usually need to be given fairly quickly once the blood vessels start to grow in your eye. 

If the blood vessels are allowed to grow for too long the blood vessels may scar the retina and this scarring cannot be treated. 

 At the moment there is no treatment for dry AMD. This is because dry AMD doesn't involve new blood vessels growing. 

Treatments for wet AMD - Anti-VEGF treatment 

 The most recent treatment available for wet AMD is with an anti-vascular endothelial growth factor (anti-VEGF) drug.  

As new blood vessels form in your eye, your body produces a chemical which stimulates further new blood vessel growth. Anti-VEGF drugs interfere with these chemicals and stop the vessels from growing. 

By stopping blood vessels growing and leaking, further damage to your sight is prevented.

Usually you will need more than one injection of Lucentis. Normally, a course of three monthly injections is given to start with and then you should be monitored every four weeks to check that the treatment is working. Many people go on to have more injections after these initial three. 

Usually anti-VEGF treatments have a high success rate and in most people they stop sight getting worse. 

About 40 per cent of people also see an improvement in their vision.   

Treating dry AMD    

Unfortunately at the moment there is no way to treat dry AMD. 

There is some evidence that high doses of vitamin A, C, E and the minerals zinc and copper when taken together may help slow down the progression of dry AMD, particularly if someone already has changes to their vision because of AMD in one eye.

 There are a number of vitamin supplements available which have been designed for people with dry AMD and you can usually buy these over the counter from your pharmacist. 

However, there is no evidence that taking high doses of these vitamins can prevent you developing AMD in the first place. 

A balanced diet with plenty of fresh fruit and vegetables is good for your general health and may also help your eye health.