Age-related macular degeneration (AMD) is the leading cause of vision loss for people over 50 in the western world. It occurs when the delicate cells of the macula – the small, central part of the retina – become damaged over the years and stop working. The macula is responsible for picking out fine detail, so when it gets damaged, the centre of your vision becomes blurred and distorted. Over time, this can get worse, resulting in blank patches in vision. Naturally, this causes activities such as recognising faces, reading and writing to become difficult.
Types of AMD
There are two types of AMD: The ‘dry’ form and the more severe ‘wet’ form. Dry AMD is the more common, developing gradually over time and usually causing only mild loss of vision. The wet form accounts for only 10% to 15% of all AMD cases, but the risk of sight loss is much greater. Because macular degeneration is an age-related process, it usually involves both eyes, although they may not be affected at the same time.
AMD is also thought to be genetic. Macular dystrophy can cause AMD-like symptoms to present in young people. In such cases, it’s likely that several members of a family also suffer from this condition.
Symptoms of AMD
AMD is not painful and never leads to total blindness because only the centre of your vision is affected. This means that almost everyone with AMD will have enough peripheral vision to get around and retain their independence. Over time, the body can begin to adapt to such limitations in vision.
In the early stages of AMD, central vision may be blurred or distorted and things may look an unusual size or shape. People with AMD may also become sensitive to light or find it harder to distinguish colours. This may happen quickly or develop over several months. If only one eye is affected, it may not be noticeable as the other eye compensates for the weakness.
Who is at risk of AMD?
The cause of AMD is unknown but several factors appear to increase the risk. These include a high-fat diet and excessive sun exposure. These all contribute to damaging the eye by weakening blood circulation and damaging the cells themselves. Risk also increases with advancing age and is much more common in those with a family history of AMD. Most importantly, smokers are a high risk category. During AMD Awareness Month, we are helping spread the word about the dangers smoking poses to vision. There are nearly 10 million people in the UK who smoke who are all at increased risk of suffering from AMD later in life.
How do optometrists test for AMD?
Optometrists have an important role to play in detecting and monitoring AMD. They will check your standard of vision and examine the macula for signs of the disease at routine eye examinations. If AMD is suspected, your optometrist may put drops into your eyes to widen the pupils and get a better view of the retina. This will help them to determine whether or not there are any signs that the condition is present.
Opticians use an Amsler Grid to monitor the progress of AMD. It’s so easy, you can try it yourself at home.
Early detection is essential to treating some types of AMD, and at Eyesite we use the most advanced eye exams to detect and diagnose as early as possible. Following your eye test, your optometrist will advise you on whether you need to be referred to a GP or hospital for medical advice. If your vision is affected by AMD, you may be given stronger glasses or special magnifiers to help you see more clearly.