Age-related macular degeneration (AMD) is a painless eye condition that generally leads to the gradual loss of central vision but can sometimes cause a rapid reduction in vision.
Central vision is used to see what is directly in front of you. In AMD, your central vision becomes increasingly blurred, leading to symptoms such as:
Symptoms of macular degeneration
AMD can cause your vision to become hazy and blind spots to develop in the middle of your visual field
Age-related macular degeneration (AMD) is not a painful condition. In fact, some people do not even realise there is a problem until their symptoms become more severe.
The main symptom of macular degeneration is blurring of your central vision. In particular, it results in:
• loss of visual acuity – visual acuity is the ability to detect fine detail, for example when you read or drive
• loss of contrast sensitivity – contrast sensitivity is the ability to see less well-defined objects, such as faces, clearly against the background
• distortion of central vision – images, writing or faces can become distorted in the centre (this is most commonly associated with wet AMD)
Your peripheral vision (outer vision) is not affected.
If you wear glasses, your central vision will still be blurred if you have macular degeneration.
Both eyes tend to be affected by AMD eventually, although you may only notice problems in one eye to begin with.
Dry age-related macular degeneration
If you have dry AMD, it may take 5-10 years before your symptoms significantly affect your daily life.
Sometimes, if only one of your eyes is affected, your healthy eye will compensate for any blurring or loss of vision. This means it will take longer before your symptoms become noticeable.
You may have dry AMD if you find that:
• you need brighter light than normal when reading
• it is difficult to read printed or written text (because it appears blurry)
• colours appear less vibrant
• you have difficulty recognising people's faces
• your vision seems hazy, or less well defined
If you are experiencing any of these symptoms, you should make an appointment with your GP or optometrist (a healthcare professional trained to recognise signs of eye problems).
Read about diagnosing age-related macular degeneration.
Wet age-related macular degeneration
In most cases wet AMD develops in people who have had a previous history of dry AMD.
If you have wet AMD, any blurring in your central vision suddenly worsens.
You may also experience other symptoms, such as:
• visual distortions – for example, straight lines may appear wavy or crooked
• blind spots – which usually appear in the middle of your visual field and become larger the longer they are left untreated
• hallucinations – seeing shapes, people and/or animals that are not really there
Seek immediate medical assistance if you experience any sudden changes in your vision such as those described above. It may be a sign you have wet AMD, which needs to be treated as soon as possible to help stop your vision getting worse.
Read more about diagnosing age-related macular degeneration.
Why it happens
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. There are two main types of AMD, called 'dry AMD' and 'wet AMD'.
Dry AMD develops when the cells of the macula become damaged as a result of a build-up of waste products called drusen. It is the most common and least serious type of AMD, accounting for around nine out of 10 cases.
The loss of vision is gradual, occurring over many years. However, an estimated one 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.
Read more about the causes of age-related macular degeneration.
Who is affected
AMD is the leading cause of visual impairment in the UK, affecting up to 500,000 people to some degree.
For reasons that are unclear, AMD tends to be more common in women than men. It is also more common in white people and people of Chinese ethnicity than people from other ethnic groups.
As would be expected by its name, age is one of the most important risk factors for AMD. The condition is most common in people over 50 and it's estimated that one in every 10 people over 65 have some degree of AMD.
How AMD is treated
There is currently no cure for either type of AMD.
With dry AMD, 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 some evidence to suggest that a diet rich in green leafy vegetables may slow the progression of dry AMD.
Wet AMD can be treated with a type of medication called anti-VEGF medication, which aims to stop your vision getting worse by helping prevent further blood vessels developing. In some cases laser surgery can also be used to destroy abnormal blood vessels.
Early diagnosis and treatment of wet AMD is essential in reducing the risk of severe loss of vision.
Read more about treating age-related macular degeneration.
Reducing your risk
It is not always possible to prevent macular degeneration as it is not clear exactly what triggers the processes that cause the condition.
Your risk of developing the condition is also closely linked to things such as 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 diet high with plenty of fruit and vegetables
moderating your consumption of alcohol (read more about recommended limits)
trying to achieve or maintain a healthy weight
wearing UV-absorbing glasses when outside for long periods