Age-related macular degeneration (AMD) involves damage to the macula and affects central vision.
How AMD affects vision
The macula is a small, but extremely important area located at the centre of the retina, the light-sensing tissue that lines the back of the eye. It is responsible for seeing fine details clearly.
If you have AMD, you lose the ability to see fine details, both close-up and at a distance. This affects only your central vision. Your side, or peripheral, vision usually remains normal. For example, when people with AMD look at a clock, they can see the clock’s outline but cannot tell what time it is; similarly, they gradually lose the ability to recognise people’s faces.
Types of AMD
There are two types of AMD. Most people (about 75%) have a form called “early” or “dry” AMD, which develops when there is a build-up of waste material under the macula and thinning of the retina at the macula. Most people with this condition have near normal vision or milder sight loss.
A minority of patients with early (dry) AMD can progress to the vision-threatening forms of AMD called late AMD.
The commonest form of late AMD is “exudative” or “wet” AMD. Wet AMD occurs when abnormal blood vessels grow underneath the retina. These unhealthy vessels leak blood and fluid, which can prevent the retina from working properly. Eventually the bleeding and scarring can lead to severe permanent loss of central vision, but the eye is not usually at risk of losing all vision (going 'blind') as the ability to see in the periphery remains. There is a rarer form of late AMD called geographic atrophy, where vision is lost through severe thinning or even loss of the macula tissue without any leaking blood vessels.
Treatments for AMD
We provide intravitreal injections (injections into the eye) for wet AMD at Moorfields using a medicine called ranibizumab (also known as Lucentis, the brand name). Ranibizumab is one of a group of anti-VEGF medicines which, when injected into the eye on a regular basis, can stop the abnormal blood vessels growing, leaking and bleeding under the retina.
Most people with wet AMD need to have these injections several times a year, so we now provide the service in several of our satellite locations, as well as at our main hospital, so that patients can get their care closer to home. Laser treatment is also available for AMD, but is not effective for most cases.
There is currently no treatment for dry AMD.