The most highly sensitive central area of the retina at the back of the eye is called the macula. It is responsible for fine detailed vision in the centre of the visual field. Macular degeneration occurs when this area of the retina becomes damaged, resulting in reduced and distorted central vision.
There are many causes of macular degeneration but the most common type is related to age and is referred to as Age Related Macular Degeneration (AMD). Although the precise cause of AMD is unknown the main risk factors include, advancing age, smoking and a family history of AMD.
There are two types of AMD, dry and wet. Dry macular degeneration, develops slowly over several years and involves the decline or death of small patches of macula cells. This results in slowly fading and unfocused central vision. In Wet Macular degeneration, new blood vessels grow into the macula. These vessels leak blood and fluid which builds up under the retina and can eventually lead to the development of scar tissue which severely effects central vision.
Early symptoms of AMD can include, straight lines appearing wavy, central vision appearing blurred, fuzzy or blacked out, and difficulty recognizing faces.
In days gone by there was no treatment available for AMD, but recent advances have discovered that some forms of laser and Anti-VGF drugs can slow or halt the progression of some types of AMD. Injections of the drugs Lucentis, Eylea and Avastin have shown promising results and researchers are continually evaluating the results and success rates of these treatments.
Q. How do I know if I have macular degeneration?
A. The best way to know is by having your eyes examined. You may need scanning of the central part of the retina (macula) with a special laser camera (OCT) and you may also need an eye angiogram (FFA or Fundus Fluorescein Angiogram).
Q. Why do I need an angiogram?
A. An eye angiogram is completely different from heart angiogram. In the eye angiogram (FFA) a coloured photo will be taken of the back of the eyes (retina), then an orange- yellow dye will be injected in your vein and further photos will be taken of the back of the eye. The angiogram will help us to confirm the diagnosis and also to find out if you qualify for subsidy for medication by the government.
Q. Is the angiogram risky?
A. It is relatively safe. You will look yellow for about 2 days and the urine may look orange. Avoid the sun for 2 days as some patients may develop a skin rash. A small percentage of patients may feel nausea during the injection and an even smaller percentage may feel the need to vomit. The chances of having serious side complications or severe allergic reaction (including life threatening complications) are very rare.
Q. What does the treatment involve?
A. Intermediate stages of macular degeneration may benefit from tablets. Wet macular degeneration may need regular injections in the eye. The doctor will apply local anaesthetics to numb the eye before the injection. Most patients tolerate the injections very well.
Q. What are the risks of the injections?
A. Some patients may not benefit from the treatment. Most patients will have no complications. Less than 1 in 1000 patient may develop an infection inside the eye which is a serious condition that needs to be treated promptly. The other possible risks (e.g. stroke, heart attack or dying) are even much rarer.
Q. How long do I need injections for?
A. If you respond well to treatment you may need to remain on regular injections for a long while. The interval between injections can vary from one patient to another from weeks to months.
Q. If I have macular degeneration will I become blind?
A. With treatment you have a reasonable chance of maintaining good vision. If left untreated, patients with macular degeneration will lose the central vision and find it difficult to read and write, recognise the details of other people faces and be able see the TV clearly. But they will maintain enough peripheral vision to navigate their way around the room (ambulatory vision).
Q. Is it hereditary?
A. There is a weak hereditary element.
Q. Is there prevention?
A. Avoid smoking. Wear sun glasses when outdoors. Eat green and yellow vegetables (if you are on warfarin you need to be careful with green vegetables) and if at all possible, eat 2 servings of fish per week (preferably oily fish like salmon and mackeral).