Age-related macular degeneration (AMD) is a painless eye condition that leads to the gradual loss of central vision. It is the most common cause of sight loss in the developed world and the third most common globally.With our ageing population and the increasing incidence of sight loss triggers, such as obesity and diabetes we are facing an epidemic of AMD in the coming decades. Around 600,000 people in the UK currently have sight loss caused by AMD and around 70,000 new cases are diagnosed every year (that's nearly 200 every day!)
What the world looks like if you have macular degeneration:
With AMD central vision becomes increasingly blurred leading to symptoms including:
- difficulty reading printed or written text (because it appears blurry)
- colours appear less vibrant
- difficulty recognising people's faces
The video clip below, taken from the Royal Institution 2013 Christmas lectures, shows Professor Peter Coffey at The Institute of Ophthalmology, UCL explaining the causes and symptoms of macular degeneration.
AMD usually affects both eyes, but the speed at which it progresses can vary from eye to eye.
Read more about the symptoms of age-related macular degeneration.
What causes AMD?
Macular degeneration develops when the macula (the part of the eye responsible for central vision) is unable to function as effectively as it used to.
It is still unclear what causes the macula to become damaged, but getting older, smoking and a family history of AMD are known to increase the risk of developing the condition.
Macular degeneration does not affect the peripheral vision (outer vision), which means it will not cause complete blindness.
Read more about the causes of age-related macular degeneration.
Types of age-related macular degeneration
There are two main types of AMD:
Dry AMD develops when the cells of the macula become damaged due to lack of nutrients and a build-up of waste products called drusens. It is the most common and least serious type of AMD accounting for around 9 out of 10 cases.
The loss of vision is gradual, occurring over many years. However, an estimated 1 in 10 people with dry AMD will then go on to develop wet AMD.
Wet AMD develops when abnormal blood vessels form underneath the macula and damage its cells (doctors sometimes refer to wet AMD as neovascular AMD).
Wet AMD is more serious and without treatment, vision can deteriorate within days.
Juvenile macular degeneration
In rare cases, macular degeneration affects younger people. This is sometimes known as juvenile macular degeneration.
It can be present at birth and, in younger people, it is almost always caused by an inherited genetic disorder, such as:
- Stargardt's disease: the most common type of juvenile macular degeneration, it can start in childhood or early adulthood.
- Best's disease: a mild type of macular degeneration, also known as Best's vitelliform retinal dystrophy.
- Sorsby's dystrophy: a type of macular degeneration that often begins between the ages of 30 and 40 and causes some loss of vision.
There is currently no cure for dry AMD so treatment is mostly based on helping a person make the most of their remaining vision, such as using magnifying lenses to help make reading easier.
There is also limited evidence that eating a diet high in leafy green vegetables and fresh fruit can slow the progression of dry AMD.
Wet AMD can be treated with a medication which helps prevent further blood vessels developing.
In some cases laser surgery can also be used to destroy abnormal blood vessels.
Treatment for wet AMD does not always lead to improved vision, but can prevent vision from worsening.
The sooner treatment is started the greater the chance of success.
Read more about treating age-related macular degeneration.
When to seek medical advice
If you notice problems with your vision, such as blurring, see your GP or optometrist.
If your vision suddenly gets worse or you notice blind spots in your field of vision, seek advice immediately. Either book an emergency appointment with an optometrist or visit your local hospital's accident and emergency (A&E) department.
Who is affected
AMD is the leading cause of visual impairment in the UK, with 600,000 people experiencing some degree of AMD.
For reasons that are unclear AMD tends to be more common in women than men.
White people and people of Chinese ethnicity are more likely to get AMD than other ethnic groups
As would be expected by its name, age is one of the most important risk factors for AMD. It is estimated that around 1 in 500 people aged 55-64 have AMD. This rises to 1 in 8 people aged 85 or over.
Reducing your risk
The best ways you can reduce your risk of getting AMD, or your AMD becoming worse, are:
- quit smoking if you are a smoker
- moderate your consumption of alcohol – read more about recommended limits
- eat a healthy diet high with at least five portions of fruit and vegetables a day
- try to achieve or maintain a healthy weight
The medical information on this page is reproduced by kind permission of NHS Choices.