AGE-RELATED MACULAR DEGENERATION
What is age-related macular degeneration (AMD)?
The retina is a thin layer of nerve tissue that collects all the visual information you see and transmits this to the brain. The macula is the central most part of the retina and is responsible for detailed central vision, used when reading and recognizing faces. Macular degeneration is a condition that causes the center of your vision to blur while peripheral vision remains largely unaffected. It is generally related to aging, which is why it is also commonly referred to as age-related macular degeneration (AMD). AMD is the leading cause of blindness in North America in adults over the age of 55.
What are the symptoms of AMD?
In the earliest stages, macular degeneration is entirely symptom free but can be detected during routine eye health examinations. The most common initial symptom is slightly blurred central vision when performing tasks that require seeing detail. Glasses cannot correct this blurred vision. Over time, the blurred area may increase in size and interfere with reading and recognizing faces. Other symptoms of AMD can cause straight lines to look wavy or distorted, and dark spots may block out portions of the central vision. Patients experience no pain with AMD.
Are there different forms?
There are two types of AMD: dry and wet. The most common is the dry AMD which is typically a milder form with slower progression. There is a gradual degeneration of the central retinal tissues that make up the macula. Symptoms generally develop slowly over time, but can still result in vision loss. However, dry AMD can turn into wet AMD. The wet form of AMD involves a sudden leakage, or bleeding, from weak blood vessels under the macula. Symptoms of wet AMD typically progress rapidly. Any sudden change in vision should be assessed by your optometrist as soon as possible.
Who is at risk of developing AMD?
The risk of developing AMD increases with age. High-risk groups include those who smoke and those who have had extensive UV exposure. This is why sunglasses are recommended for all ages.
AMD is also associated with conditions such as high blood pressure, arteriosclerosis, obesity and those with a family history of AMD. Individuals with diets high in fat, cholesterol and sugar, and low in antioxidants are more likely to be affected by age-related macular degeneration.
How can I prevent AMD?
Lifelong UV protection and good nutrition are believed to play a key role in preventing AMD. Living a healthy lifestyle by keeping your blood pressure down, reducing your intake of fatty foods and not smoking are all recommended. A diet high in antioxidants such as beta-carotene (a form of vitamin A), vitamins C and E, zinc, lutein, zeaxanthin, selenium and omega 3 fatty acids may help prevent AMD. Most of these antioxidants are found in green leafy vegetables, yellow and orange fruit, fish, and whole grains.
Regular eye examinations by your optometrist are also important in the early detection of AMD as early signs may be found even if no symptoms are noticed. Your optometrist can discuss ways to minimize the possibility of vision loss due to AMD.
Is there treatment for age-related macular degeneration?
Lifestyle modifications in earlier life, such as sunglasses to reduce UV radiation and smoking cessation, may help to prevent AMD. Currently, the progression of certain stages of dry AMD is slowed with ocular vitamin supplementation. The use of vitamins will not reverse any vision loss that has already occurred, nor will it stop the progression of AMD completely. Speak to your eye doctor before starting any ocular vitamins.
The progression of many cases of wet AMD can be treated with medications injected into the eye to stop leaking blood vessels by an ophthalmologist.
Regular eye examinations from your optometrist will inform you of the right treatments and prevention strategies for you.