Last Updated: 11 December 2018
Age-related
macular degeneration (AMD) is a painless eye condition that causes you to lose
central vision, usually in both eyes. Central vision is what you see when
you focus straight ahead. In AMD, this vision becomes increasingly blurred,
which means:
- reading
becomes difficult
- colours
appear less vibrant
- people's faces are difficult to recognise.
This sight loss usually happens
gradually over time, although it can sometimes be rapid. AMD doesn't affect your
peripheral vision (side vision), which means it will not cause complete blindness.
When to seek medical advice
You must visit your doctor/ GP or optometrist if your vision is getting
gradually worse. If your vision suddenly gets worse, images are distorted or
you notice blind spots in your field of vision, seek medical advice immediately
and book an emergency appointment with an optometrist. If AMD is suspected, you'll be
referred to an ophthalmologist (eye specialist) for tests and any necessary
treatment.
Why it happens
Macular degeneration develops when
the part of the eye responsible for central vision (the macula) is unable to
function as effectively as it used to. There are two main types – dry
AMD and wet AMD.
Dry AMD
Dry AMD develops when the cells of
the macula become damaged by a build-up of deposits called drusen.
It's the most common and least serious type of AMD, accounting for
around 9 out of 10 cases. Vision loss is gradual,
occurring over many years. However, an estimated 1 in 10 people with
dry AMD go on to develop wet AMD.
Wet AMD
Wet AMD – sometimes called
neovascular AMD – develops when abnormal blood vessels form
underneath the macula and damage its cells. Wet AMD is more serious than dry AMD.
Without treatment, vision can deteriorate within days.
Who is affected?
AMD currently affects more than
600,000 people in the UK and is the leading cause of vision loss. By 2020, it's predicted almost
700,000 people will have late-stage AMD in the UK. For reasons that are unclear, AMD
tends to be more common in women than men. It's also more common in white and
Chinese people.
The condition is most common in
people over the age of 50. It is estimated 1 in every 10 people over 65
have some degree of AMD.
Treating macular degeneration
There is currently no cure for either
type of AMD. With dry AMD, treatment aims to help a person make the
most of their remaining vision – for example, magnifying lenses can
be used to make reading easier.
There is some evidence to suggest a
diet rich in leafy green vegetables may slow the progression of dry AMD. Wet AMD can be treated with
anti-vascular endothelial growth factor (anti-VEGF) medication. This aims to
stop your vision getting worse by preventing further blood vessels developing.
In some cases, laser surgery can also
be used to destroy abnormal blood vessels. The early diagnosis and treatment of
wet AMD is essential for reducing the risk of severe vision loss.
Reducing your risk
It's not always possible to prevent
macular degeneration because it's not clear exactly what triggers the processes
that cause the condition. Your risk of developing AMD is
closely linked to your age and whether you have a family history of the
condition.
However, you may be able
to reduce your risk of developing AMD, or help prevent
it getting worse, by:
- stopping smoking if you smoke
- eating a healthy, balanced diet that includes
plenty of fruit and vegetables
- moderating your consumption of alcohol – read more about alcohol units and recommendations
- trying to achieve or maintain a healthy weight
- wearing
UV-absorbing glasses when outside for long periods.
Juvenile macular degeneration
In rare cases, macular
degeneration can affect younger people. This is sometimes known as juvenile
macular degeneration. It can be present at birth or develop
later, but it's almost always caused by an inherited genetic disorder, such as:
- Stargardt's disease –
the most common cause of juvenile macular degeneration, this can start in
childhood or early adulthood
- Best's disease –
also known as Best's vitelliform macular dystrophy
- Sorsby's dystrophy –
this often begins between the ages of 30 and 40.
Source: NHS Choices
