Macular degeneration (MD)

Macular degeneration (MD) happens when the macula at the back of the eye which affects a person’s central vision becomes damaged. This can make it harder to see fine detail, such as recognising faces, or to read or watch television. However, this does not normally affect your ability to walk around as the periphery of your vision should not be affected. 

Does it cause blindness?

MD is one the leading causes of blindness worldwide. However, most people with MD still have their peripheral (side) vision and so can see well enough to get around. However, they may not be able to see well enough to read without strong magnification. 

Does it happen more as you get older? 

The most common forms of MD happen more as you get older and are known as age-related macular degeneration (AMD). Around one in 10 people aged 65 or over show some signs of AMD. Some younger people may have MD caused by a genetic condition but this is less common than AMD. 

What are the symptoms of AMD? 

• Gradual loss of central vision

• Straight lines become distorted or wavy

• Blurry vision when reading even with your normal reading glasses

• Rapid-onset loss of central vision

• Blind spot/dark patch in or near the central vision which does not go away

• Sensitive to bright light, or difficult to adapt when going from a dark to a light environment

These symptoms are more noticeable if you look for them with each eye separately, because if you have both eyes open then the better eye may compensate for the other one. We recommend you check your vision in each eye separately on a regular basis by looking at some detail, such as a book or magazine and covering each eye in turn. This will help you notice any changes in your vision early.

Can I do anything to protect myself from getting AMD? 

Smoking is known as a major risk factor for developing AMD so if you smoke, try to stop. It is also believed that having a diet that is rich in coloured fruit and vegetables (for example, kale, spinach, celery and broccoli) may reduce your risk of developing AMD. Eat fish with high levels of omega-3 fatty acids such as salmon, sardines, mackerel. Avoid a diet high in sugar and refined carbohydrates. A link has been found between obesity and AMD so you should try to maintain a healthy weight. Engage in physical activity or exercise.

Other factors that increase your risk of developing AMD include having a family history of the condition. It is slightly more common in women than men. Moreover, exposure to ultraviolet light is linked to AMD so we recommend that you wear UV-absorbing glasses when you are going to be outside for long periods. Not all sunglasses will absorb the UV, so it is important to check this. The exact cause of AMD is not yet known, so you may develop it even if you don’t have any of these risk factors. There are lots of dietary supplements on the market which claim to be beneficial for eye health. They may be helpful for some people. Discuss whether or not they may be helpful for you with your optometrist. You should note that if you smoke or have been exposed to asbestos you should not take beta carotene.

I have heard that AMD can be ‘wet’ or ‘dry’ – is this right? 

AMD can be classified as early or late. Early AMD is always dry AMD. This is when yellow deposits, known as drusen, build up behind the macula. Most people with early AMD have normal near vision. There is no treatment for early AMD. A minority of people with early AMD can progress to late AMD. Late AMD may be ‘wet’ or ‘dry’.

he commonest form of late AMD is the wet form. This happens when abnormal blood vessels begin to grow behind the macula and leak fluid. This pushes the macula away from its blood supply at the back of your eye and causes a rapid loss of vision. It is usually associated with you noticing distorted vision (straight lines become wavy, or you have a blank spot or smudge in the centre of your vision). You can check this yourself by looking at straight lines such as door and window frames or Venetian blinds. Or, you can look at a grid of squares printed on paper, called an Amsler chart (Your optometrist will be able to advise you on this). It is important to do this with each eye separately and while wearing your glasses, if you need them. Wet AMD can be treated and this is normally done by injecting a drug into the gel inside your eye, so if you notice these symptoms, you need to see your optometrist straight away. Late dry AMD is called geographic atrophy and is rarer than late wet AMD. This is where you lose vision because the retina at your macula thins but there are no leaking blood vessels. There is no treatment for geographic atrophy/late dry AMD but your optometrist can advise you on special magnifiers which can help you with reading.

It is important to spot any changes early by checking the vision in each eye separately and contacting your optometrist immediately if your vision suddenly becomes distorted or you have a blank spot in your vision. If you have wet AMD, your optometrist will refer you to a specialist eye doctor, known as an ophthalmologist. The ophthalmologist will decide if you need treatment by taking some scans of the back of your eye to show the thickness of the retina. They may also inject you in your arm with some special dye to see how this travels through the back of your eye, while taking a series of flash photographs of the inside of your eye.