|Age related macular degeneration is a common condition that is seen in 30% of patients over the age of 65 years, usually in its mild form. It also goes by a number of other names:
It is a condition that affects the central part of the retina, known as the macula. The retina is the important membrane that lines the inside of the eye and has the role of acting like the film in a camera. It collects the light and sends the visual information back to the brain. The very most important part of the retina is the central part called the macula, and our central fine vision comes from this area; our reading vision, our colour vision and vision for close work. Unfortunately, this is exactly where macula degeneration has its effect.
Can I go blind with macular degeneration?
This is the most common question, and fortunately the answer is good. Macular degeneration can only affect the central vision, not all the vision. People can not go completely blind from macular degeneration by itself. When people fear blindness, they worry about not being able to distinguish light from dark, being unable to move around freely and being totally dependent on others. This does not happen with macular degeneration. The peripheral vision is preserved, which is required for navigating freely in your environment. This means that even patients with the most severe macular degeneration can see in the distance and can walk around without bumping into things.
What causes macular degeneration?
It is a process that is associated with ageing. There is some evidence that there is a genetic component (if you have a relative with it, you are at a slightly higher risk than other people, but it does not automatically go through the family), exposure to UV light and deficiency of some vitamins. It is not related to using the eyes, and close work such as reading and knitting does not bring it on or worsen it. There is no relationship to exposure to certain chemicals or environmental conditions.
What types are there?
There are two types of macular degeneration, the more common, slower and milder ‘dry’ type, and the less common, more rapid and more severe ‘wet’ type.
‘Dry’ macular degeneration
In this type of macular degeneration there is a slow ‘wear and tear’ of the central part of the retina. If the vision is lost, it is often so slow that patients do not notice.
The earliest sign are what are known as ‘drusen’, which are small white deposits seen in the retina. These are actually small collections of retinal waste products that have accumulated over a lifetime and have not been disposed of efficiently.
Apart from decreased central vision and difficulty reading, other symptoms of dry macular degeneration are needing a much brighter light to read than before and taking longer to adjust from light to dark and from dark to light
The dry form of macular degeneration is slow and generally milder. There are no known treatments that reverse it, slow it down or stop it.
‘Wet’ macular degeneration
This type of macular degeneration is less common but more severe. In this type abnormal blood vessels (‘choroidal neovascularisation’) grow underneath the retina and cause damage by leaking and bleeding. This can cause the central vision to deteriorate more quickly, often in weeks to days. Without treatment, eventually the central vision is lost.
It needs to be diagnosed and treated early in order to get the best outcome.
Will I lose vision in the other eye?
Unfortunately, ARMD typically affects both eyes. Before developing the wet form of the disease, the patient will have the dry form of the disease, but often so mildly that they have no symptoms. The eyes can be affected asymmetrically, with one eye badly affected and the other only very mildly affected.
Is there any treatment that is effective for ‘dry’ ARMD
Unfortunately there is no definite treatment for the more common ‘wear and tear’ dry ARMD. This means that currently there is no treatment that can reverse dry ARMD, stop it or slow it down. However, patients can be reassured that visual loss is very slow.