Age related macular degeneration
Age-related macular degeneration (AMD) involves damage to the macula and affects central vision.
AMD is the most common cause of vision impairment in Australia. One in 7 people over the age of 50 are affected. People with a family history of AMD have a 50% chance of developing the disease. If left untreated, AMD can cause gradual loss of sight in the centre of your vision. Reading, watching TV, driving, working on a computer and performing almost every common task becomes difficult.
AMD can only be diagnosed by examining the retina, hence regular eye check at Westside Eye Clinic is important.
How AMD affects vision
The macula is a small, but an 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 (such as reading) and at a distance (e.g. when looking at a clock). This affects only your central vision. Your 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% – 80%) have a form called “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 dry AMD can progress to the vision-threatening forms of AMD called late AMD. Late AMD called geographic atrophy results in vision loss through severe thinning or even loss of the macula tissue without any leaking blood vessels.
The commonest form of late AMD is “exudative” or “wet” AMD.
Wet AMD occurs when abnormal blood vessels grow underneath the macular. These unhealthy and abnormal vessels leak blood and fluid, which can prevent the retina from working properly. Eventually the bleeding and scarring can lead to severe and 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.
Treatment for AMD
Westside Eye Clinic provide intravitreal injections (injections into the eye) for wet AMD using a medicine classified as anti-VEGF (VEGF stands for vascular endothelial growth factor). Anti-VEGF medicines are injected into the eye on a regular basis and can stop the abnormal blood vessels growing, leaking and bleeding underneath the macular.
Most people with wet AMD need to have these injections regularly for many years with an eye doctor.
There is currently no treatment for dry AMD.
Important steps following diagnosis of AMD
Even after receiving a diagnosis of dry macular degeneration, you can take steps that may help slow vision loss.
- Don’t smoke. If you smoke, please ask your GP for help to quit smoking.
- Healthy diet. The antioxidant vitamins in fruits and vegetables contribute to eye health. Spinach, lettuce, Kale, broccoli, peas and other coloured vegetables have high levels of antioxidants, including lutein and zeaxanthin, which may benefit people with age-related macular degeneration. Foods containing high levels of zinc may also be of particular value in patients with macular degeneration. These include high-protein foods, such as nuts and seafood.
- Research studies (such as Blue Mountains Eye Study) have shown that a diet high in omega-3 fatty acids, such as that found in fish for example sardines, salmon, tuna, may lower the risk for advanced AMD.
- Manage your other medical conditions. If you have heart disease or high blood pressure, for example, take your medication and follow your GP’s instructions for controlling your heart condition.
- Maintain a healthy weight by exercising regularly and controlling your diet.
- Have routine eye exams. Ask your eye doctor at Westside Eye Clinic about the recommended schedule for follow-up exams. In between checkups, you can do a self-assessment of your vision using an Amsler grid. These steps will help identify if your AMD develops into wet AMD, which can be treated with anti-VEGF medication. Remember prompt treatment is the key in managing wet AMD.
Vitamin supplements for AMD
For people with intermediate or advanced AMD, taking a high-dose formulation of antioxidant vitamins and minerals may help reduce the risk of vision loss.
AREDS 2 Research showed benefit in a formulation that includes:
- 500 milligrams (mg) of vitamin C
- 400 international units (IU) of vitamin E
- 10 mg of lutein
- 2 mg of zeaxanthin
- 25 or 80 mg of zinc (as zinc oxide)
- 2 mg of copper (as cupric oxide)
The evidence doesn’t show benefit in these supplements for people with early-stage dry age-related macular degeneration. Please note as high doses of vitamin E may increase the risk of heart failure and other complications, always ask your GP if taking vitamin supplements is safe for you.