AMD | Patient Talk

Symptoms of macular degeneration

[Original article on NHS Choices website]

The exact cause of macular degeneration isn’t known, but the condition develops as the eye ages.

Age-related macular degeneration (AMD) is caused by a problem with part of the eye called the macula. The macula is the spot at the centre of your retina (the nerve tissue that lines the back of your eye).

The macula is where incoming rays of light are focused. It helps you see things directly in front of you and is used for close, detailed activities, such as reading and writing.

Dry AMD

As you get older, the light-sensitive cells in the macula can start to break down. This tends to occur gradually, often over many years.

Waste products can also begin to build up in your retina, forming small deposits called drusen. Drusen are a common feature of dry AMD and tend to increase in size as the condition progresses.

As dry AMD progresses, you’ll have fewer light-sensitive cells in your macula, causing your central vision to deteriorate. A blurred spot will develop in the centre of your vision, making your central vision less well-defined. As a result, you may need more light when reading and carrying out other close work.

Wet AMD

In cases of wet AMD, tiny new blood vessels begin to grow underneath the macula. It’s thought these blood vessels form as an attempt by the body to clear away the drusen from the retina.

Unfortunately, the blood vessels form in the wrong place and cause more harm than good. They can leak blood and fluid into the eye, which can cause scarring and damage to your macula.

The damage and scarring causes the more serious symptoms of wet AMD to develop, such as distorted vision and blind spots.

Increased risk

It’s unclear what triggers the processes that lead to AMD, but a number of things increase your risk of developing it. These are described below.

Age

The older a person gets, the more likely they are to develop at least some degree of AMD.

Most cases start developing in people aged 50 or over and rise sharply with age. It’s estimated 1 in every 10 people over 65 has some signs of AMD.

Family history

AMD has been known to run in families. If your parents, brothers or sisters develop AMD, it’s thought your risk of also developing the condition is increased.

This suggests certain genes you inherit from your parents may increase your risk of getting AMD. However, it’s not clear which genes are involved and how they’re passed through families.

Smoking

A person who smokes is up to four times more likely to develop AMD than someone who’s never smoked.

The longer you’ve been smoking, the greater your risk of getting AMD. You’re at even greater risk if you smoke and have a family history of AMD.

Ethnicity

Studies have found rates of AMD are highest in white and Chinese people, and lower in black people. This could be the result of genetics.

Other possible risk factors

The following things may increase your risk of developing AMD, although this hasn’t yet been proven.

Alcohol

It’s possible drinking more than four units of alcohol a day over many years may increase your risk of developing early AMD.

Sunlight

If you’re exposed to lots of sunlight during your lifetime, your risk of developing macular degeneration may be increased. To protect yourself, you should wear UV-absorbing sunglasses if you spend long periods of time outside in bright sunlight.

Obesity

Some studies have reported being obese – having a body mass index (BMI) of 30 or greater – may increase your chance of developing AMD.

High blood pressure and heart disease

There’s some limited evidence that having a history of high blood pressure (hypertension) or coronary heart disease may increase your risk of developing AMD.

Macula: The macula is a small spot at the centre of the retina. It is the part of your eye where incoming rays of light are focused.
Retina: The retina is the nerve tissue lining the back of the eye. It senses light and colour and sends it to the brain as electrical impulse

Symptoms of macular degeneration

Age-related macular degeneration (AMD) isn’t a painful condition. Some people don’t realise they have it until they notice a loss of vision.

The main symptom of macular degeneration is blurring of your central vision (what you see when you focus straight ahead). This means:

you lose visual acuity – the ability to see fine detail, so reading and driving become difficult

you lose contrast sensitivity – the ability to distinguish between objects such as faces against a background

images, writing or faces can become distorted in the centre – most commonly associated with wet AMD

Your peripheral vision (side vision) isn’t affected. Glasses won’t be able to correct your blurred central vision.

Both eyes tend to eventually be affected by AMD, although you may only notice problems in one eye to begin with.

Dry AMD

If you have dry AMD, it may take 5 to 10 years before your loss of vision significantly affects your daily life.

Sometimes your healthy eye will compensate for any blurring or vision loss if only one of your eyes is affected. This means it will take longer before your symptoms become noticeable.

You may have dry AMD if:

you need brighter light than normal when reading

text appears blurry

colours appear less vibrant

you have difficulty recognising people’s faces

your vision seems hazy or less well defined

If you’re experiencing any of these symptoms, you should make an appointment with your GP or local optometrist (a healthcare professional trained to recognise signs of eye problems).

Read about diagnosing age-related macular degeneration.

Wet AMD

In most cases, wet AMD develops in people who’ve already had dry AMD.

If you have wet AMD, any blurring in your central vision will suddenly worsen.

You may also experience other symptoms, such as:

visual distortions – for example, straight lines may appear wavy or crooked

blind spots – these usually appear in the middle of your visual field and become larger the longer they’re left untreated

hallucinations – seeing shapes, people or animals that aren’t really there

See complications of AMD for more information.

Book an emergency appointment with an optometrist if you experience sudden changes in your vision, such as those described above.

Wet AMD needs to be treated as soon as possible to stop your vision getting worse.