What is Age-Related Macular Degeneration (AMD)?
Age-related macular degeneration (AMD) is a retinal disease that affects the small central area of the retina known as the macula.
With AMD your vision may be less sharp, distorted or blurry which can make it hard to do everyday tasks like reading, driving and even recognizing a friend’s face.
The exact cause of AMD is unknown but it develops as the eye ages. It is the leading cause of vision loss in older Americans.
There are two types of AMD, wet and dry. The most common form is dry AMD which develops and worsens slowly over time. Wet AMD is less common but can progress much faster and cause loss of central vision in one or both eyes.
The Retina and Age-Related Macular Degeneration
The retina is a thin layer of light-sensitive nerve tissue that lines the back of the eye cavity.
When light enters the eye, it passes through the iris to the retina where images are focused and are converted into electrical impulses that travel through the optic nerve to the brain resulting in sight.
Watch What is a Retina to learn more.
With early dry AMD, pale yellow lesions called drusen can develop and parts of the macula can deteriorate, causing vision loss over time. With wet AMD, abnormal blood vessels grow beneath the retina which may bleed or hemorrhage causing wavy lines or loss of central vision.
Who is at risk?
You may wonder if age-related macular degeneration can be prevented. Like most things in life, there is no easy answer.
The primary risk factor for AMD is age—the older you are, the greater your risk. Also, people with a family history of AMD are at higher risk, as are women and people who are Caucasian or of European descent.
Other factors are also known to increase your risk for AMD:
- Cigarette smoking
- Hypertension (high blood pressure)
- Excessive sun exposure
- Diet deficient in fruits and vegetables
What are the symptoms?
In the early stages, AMD may have no symptoms at all.
When the disease progresses, the symptoms are:
- Distortion (warping) of straight lines
- A decrease in the intensity or brightness of colors
As macular degeneration progresses, symptoms include:
- A gradual or sudden loss of central vision, or dark, blurry areas in the center of vision
If you experience any of these symptoms, see a retina specialist as soon as possible.
How is it diagnosed?
AMD can be diagnosed during an eye exam with an eye doctor or retina specialist.
During this exam, your physician will place drops in your eyes to make your pupils dilate (open widely) to allow a better view of the inside of your eye, especially your retinal tissue.
You also may be asked to look at an Amsler grid, commonly black lines on a white background with a dot in the middle. Cover one eye at a time, (keeping your glasses on if you wear them) hold the grid 12 inches away and look at the dot. If the lines appear wavy, dim, irregular or fuzzy let your eye doctor know right away.
AMD can also be diagnosed through a variety of advanced imaging techniques.
What are the treatments?
Wet-AMD treatment has been revolutionized in recent years after the discovery of a family of compounds in the body knowns as vascular endothelial growth factor (VEGF). VEGF regulates the growth of abnormal new blood vessels in the eye—known as neovascularization—that can lead to wet AMD.
Wet AMD cannot be cured, but its progression may be stopped with intravitreal (in-the-eye) anti-VEGF injections. If your retina specialist treats you with anti-VEGF injections, you’ll be given eye drops that numb any pain and minimize discomfort first.
Anti-VEGF drugs can preserve vision for AMD patients. That means if you have wet AMD you have a much better chance of maintaining your central vision so you can read, drive, recognize faces, and live a normal life.
No treatment can prevent visual loss for patients with the advanced form of dry AMD. However, the Age-Related Eye Disease Studies (AREDS), conducted by the National Eye Institute, found that a nutritional supplement formula may delay and prevent intermediate dry AMD from moving to the advanced form.
If you have advanced dry AMD, you may want to take an AREDS-2 supplement formula, which is widely available over the counter, containing:
- Vitamin C
- Vitamin E