Age Related Macular Degeneration
This is a progressive condition that can affect people as they get older. It tends to run in families. There are different forms which have different outcomes for vision. AMD accounts for 45% of people over 70 years of age who are registered as legally blind. With macular degeneration central vision does become severely affected but sufferers will retain a certain level of peripheral vision.
The following figures relate to the percentage of the population suffering from AMD.
4% of over 40s
9% of over 50s
23% of over 60s
30% of over 80s
What causes AMD?
AMD is the result of ageing processes in the eye. The part of the retina (the tissue on the inside of the eye) responsible for seeing fine detail and colours and for making out facial features and shapes, is the macula. The macula is affected in age-related macular degeneration. This part of the eye suffers “wear and tear” over time and it is believed that a build-up of waste material at and around the macula is the reason for the reduction in vision that occurs in this condition.
There are two types of AMD, Dry and Wet.
Dry AMD is the most common form of the condition and usually causes gradual changes in vision, often little changes over many years.
Wet AMD affects a much smaller percentage of sufferers and is usually of sudden onset with significant and obvious reduction in vision. In Wet AMD, abnormal blood vessels develop beneath the macula and begin to leak. This leakage of fluid results in straight lines looking wavy or distorted. In some cases of Wet AMD treatment is possible, but it is vital that referral to a retinal specialist occurs as soon as possible.
How is AMD detected and diagnosed?
People with AMD may notice that their vision has deteriorated. Many patients do not realise that they have a problem until their vision becomes significantly blurred. Optometrists perform a number of tests in an examination that enable them to detect the presence of AMD in the early stages.
Patients with AMD often report that sections of the Amsler grid appear to be distorted or missing as illustrated below
Optometrists will usually refer patients whom they suspect have AMD to an ophthalmologist (eye specialist) for confirmation of the diagnosis.
There is no way to reverse the damage done to the retina in AMD. Where new blood vessels have appeared in the macula area (Wet AMD), laser surgery may be used. In this treatment a focused, intense beam of laser light is used to seal off leaking blood vessels and to prevent new vessels growing. This treatment is most successful in the early stages of the condition. However there is a risk that the damage will continue to develop even after getting the laser treatment and usually the treatment aims to stop things getting worse rather than returning vision to what it was before the condition developed.
While there is little that can be done to prevent or cure AMD, people with the disease can be helped to continue functioning normally. Many patients with AMD will eventually come under the classification of being a low vision patient. Optometrists can discuss and advise on low vision aids such as magnifiers, high-powered spectacles and miniature telescopes amongst others.
What should you do to avoid AMD?
For treatment of AMD to be effective, it must be diagnosed as early as possible. Regular eye examinations are the key to early detection of retinal changes and other signs of disease. If you notice any change in the quality of your vision, have your eyes examined immediately. Regular examinations are particularly important for people over the age of 50 years and people whose families have a history of eye conditions.
The latest research advises that diet can be useful in avoiding this problem, UV exposure and smoking has been indicated as a risk factor for developing the condition. Some people are advised to take oral vitamin supplements to reduce the risk of developing AMD, always consult your optometrist or ophthalmologist before taking any such supplements.
The following fruit and vegetables have been reported to have some effect in reducing the risk of developing AMD
Yellow / Orange – corn, oranges, squash
Green – kale, brocolli, cabbage