What is AMD?
AGE-RELATED MACULAR DEGENERATION
Age related macular degeneration develops when the part of the eye responsible for central vision (the macula) is unable to function as effectively as it used to due to aging. There are two main types – dry AMD and wet AMD.
Dry AMD develops when the cells of the macula become damaged by a build-up of deposits called drusen. It's the most common and least serious type of AMD, accounting for around 9 out of 10 cases.
Vision loss is gradual, occurring over many years. However, an estimated 1 in 10 people with dry AMD go on to develop wet AMD.
Wet AMD – sometimes called neovascular AMD – develops when abnormal blood vessels form underneath the macula and damage its cells.
Wet AMD is more serious than dry AMD. Without treatment, vision can deteriorate within days.
Who has an increased risk?
Age - The older a person gets, the more likely they are to develop at least some degree of AMD.
Smoking - A person who smokes is up to four times more likely to develop AMD than someone who's never smoked.
Ethnicity - Studies have found rates of AMD are highest in white and Chinese people
Excess sunlight exposure to the eye
Obesity and heart disease
How is age-related macular degeneration diagnosed?
In addition to vision testing and examination of your eye, your eye doctor will need to photograph your retinas to see what damage, if any, macular degeneration has caused.
As well as confirming the diagnosis, the images will prove useful in planning your treatment. There are several different ways of taking pictures of the retina, which includes:
Fundus photography - A fundus camera is a special camera used to take photographs of the inside of your eye.
OCT scan - uses special rays of light to scan your retina and produce an image of it. This can provide detailed information about your macula. For example, it will tell your ophthalmologist whether your macula is thickened or abnormal, and whether any fluid has leaked into the retina.
Less commonly Fluorescein angiography and Indocyanine green (ICG) angiography – involves taking photograph of the retina with special contrast in the vein of the arm.
How is age-related macular degeneration treated?
With dry AMD, treatment aims to help a person make the most of their remaining vision – for example, magnifying lenses can be used to make reading easier. There's some evidence to suggest a diet rich in leafy green vegetables may slow the progression of dry AMD. There's some evidence a diet high in vitamins A (beta-carotene), C and E – as well as substances called lutein and zeaxanthin – may slow the progression of dry AMD, and possibly even reduce your risk of getting wet AMD. Talk to your eye doctor about whether these could help you. If you smoke then it is very important for you to work with you GP to stop smoking.
For dry AMD, you should regularly check the vision in each of your eye separately every one to two weeks. You can do this by placing a special Amsler grid (see here) on your fridge door and look at it with each eye separately covering the other eye. If you have an Apple iPad, you can monitor your vision with the Melbourne Rapid Fields app, co-invented by Dr George Kong.
Wet AMD can be treated with anti-vascular endothelial growth factor (anti-VEGF) medication with sterile injection in clinic. These include Lucentis and Eylea. The aim of these medications is to stop your vision getting worse by preventing further blood vessels developing.
To start with, you'll have a monthly injection for three consecutive months. Your visual acuity will then be monitored during a maintenance phase. If your vision deteriorates during the maintenance phase, and it's thought to be caused by further fluid leakage, you may be given another injection. Monitoring will continue and you'll have injections as necessary, with at least one month between injections.
Treatment will be stopped if your condition doesn't show signs of improvement or continues to get worse.
Common side effects of injection into the eye with Lucentis or Eylea include:
minor bleeding in the eye
feeling like there's something in the eye
inflammation or irritation of the eye
brief increased pressure within the eye