Understanding Macular Degeneration
The central vision is decreased due to age-related changes in the central retina or macula. This is the most common cause of legal blindness in Australia.
Deposits in the layer under the retina can build up with time. This can lead to thinning of the central retina (‘dry’ macular degeneration) and a slow deterioration of central vision. A second, less common complication of age-related macular degeneration involves the growth of abnormal blood vessels under the macula. This can lead to fluid or blood under the retina (‘wet’ macular degeneration) and a rapid decrease in central vision.
Prevention is better than a cure. Vitamins, antioxidants and zinc supplements may slow the progression of the disease. Ceasing smoking is another great prevention tactic. Intravitreal injections of vascular growth factor inhibitors of AVASTIN or LUCENTIS are used for ‘wet’ AMD. They are very successful and 95% of eyes do not lose vision (lose more than 3 lines on the chart), but repeated injections over 2 or more years are needed.
An average of 6 injections per year is needed. Laser treatment is only used occasionally for the ‘wet’ form of age-related macular degeneration. However, only about 5% of ‘wet’ macular degeneration is treatable either with Argon laser or Visudyne Photodynamic therapy in conjunction with injections. Optimum lighting, glasses and sometimes magnifying devices are helpful in this condition. Blind registration and pensions with Centrelink and taxi subsidies are available only if legally blind in both eyes.
This condition never causes complete blindness, although it may decrease central (reading) vision. The peripheral (side) vision is retained. Thus, a patient with severe macular degeneration will still be able to get around independently. Often, the condition presents in one eye only and the other eye retains normal vision. The risk of loss in the second eye, however, is about 10% every year, so it is important to monitor the other eye regularly. This is done by looking at a grid every week to check for increasing distortions or missing vision. If any changes are noted please make an appointment to see the eye doctor immediately.
ARMD is age-related, and the increase in a number of cases of this blinding disease is caused in part by the general population getting older. The relative risk odds ratio for ARMD in Australians was estimated at 119 times greater for people over the age of 80 years compared to the reference age group aged 40 to 69.
Do not smoke. Smoking is linked to ARMD with a small odds ratio of 2, but it is a modifiable risk. Consume a diet of fresh fruit and vegetables (especially corn and orange juice). Eat fish, especially salmon and tuna, 3 times per week. Eggs are good and a low G.I. (Glycaemic Index) diet.
Supplements for Prevention
Take Luteinvision (Blackmore’s) or similar Lutein and Zeaxanthin supplements and high doses of vitamins and zinc Macuvision, or a combination tablet: Ultravision (Macuvision and Lutein).
Ultravision: available at most optometrist and some chemist offices. Macutec: available in Australia. For more information, please phone 1 800 622 8832. This has vitamins like Ultravision and fish oil.