Age-related macular degeneration (AMD): Symptoms, diagnosis, treatment and prevention
Age-related macular degeneration, or AMD, is the leading cause of visual impairment in the UK.
AMD doesn't cause pain, but central vision is gradually lost as the central portion of the retina, called the macula, deteriorates. The retina is the light-sensing nerve tissue at the back of the eye.
The macula is the most important region of the eye. It is a very small portion of the retina and is about 5mm in diameter. The macula is loaded with photoreceptors that allow you to read, watch television, drive, sew -- anything that requires focused, precise vision.
Outside of the macula there are far fewer photoreceptors and image resolution is much poorer. Although these uninvolved portions of the retina can continue to process images along the edge of your field of vision, the tissue damage caused by macular degeneration distorts or obscures part of the crisp central images that your eye transmits to your brain.
In the dry form of macular degeneration, tiny yellow deposits develop beneath the macula, signalling the degeneration and thinning of nerve tissue. A small number of cases develop into the wet, or neovascular, form of macular degeneration, in which abnormal blood vessels grow beneath the macula. As these vessels leak blood and fluid onto and underneath the retina, retinal cells die, causing blurs and blank spots in your field of vision.
Most people with age-related macular degeneration have the dry form of the disease and will not lose central vision. However, the dry form of macular degeneration can lead to the wet form. Although only about 10% of people with macular degeneration develop the wet form, they make up the majority of those who experience serious vision loss as a result of the disease.
It is very important for people with macular degeneration to monitor their eyesight carefully and see their eye specialist on a regular basis.
What causes macular degeneration?
Causes are believed to be genetically inherited, but environmental factors can also contribute. Macular degeneration often runs in families. Research involving twins showed that genetic factors play a significant role in causing the disease.
What are the symptoms of macular degeneration?
In its early stages, age-related macular degeneration may not have any symptoms and therefore may not be recognised until it progresses or affects both eyes. The main symptom of macular degeneration is blurring of central vision. This may progress to a gradual loss of central vision.
Symptoms of macular degeneration include:
- Straight lines appearing distorted (wavy), or the centre of vision becoming distorted.
- Dark, blurry areas or blind spots appearing in the centre of vision.
- Diminished or altered colour perception.
- Difficulty recognising people’s faces, reading text or seeing television clearly.
If you experience any of these symptoms, seek medical advice as soon as possible.