Age-related macular degeneration – also called macular degeneration, AMD or ARMD – is the leading cause of severe vision loss among Americans, more than glaucoma and cataracts combined.
What is Macular Degeneration?
Macular degeneration is deterioration of the macula, which is the small central area of the retina of the eye that is responsible for sharp, central vision. Macular degeneration has three stages: early macular degeneration, intermediate macular degeneration and late macular degeneration.
- Early macular degeneration – People with early macular degeneration typically do not have vision loss. Early macular degeneration is diagnosed by the presence of medium-sized drusen, which are yellow deposits beneath the retina that are about the width of an average human hair.
- Intermediate macular degeneration – At this stage, there may be some vision loss, but most people will not experience any symptoms. People with intermediate macular degeneration will usually have large drusen, pigment changes in the retina, or both.
- Late macular degeneration – In addition to drusen, vision loss from damage to the macula will also become noticeable in this stage.
There are also two basic types of macular degeneration: dry and wet.
- Dry macular degeneration (non-neovascular) – Dry macular degeneration is the more common type of macular degeneration. With dry macular degeneration, the tissue of the macula gradually becomes thin and stops working properly.
- Wet macular degeneration (neovascular) – Wet macular degeneration is less common, but much more serious. Wet macular degeneration occurs when fluids leak from newly-formed blood vessels under the macula. These vessels may leak blood or other fluids, causing scarring of the macula. You lose vision faster with wet macular degeneration than with dry macular degeneration.
The biggest risk factor for macular degeneration is age. Your risk increases as you age, and the disease is most likely to occur in those 55 and older. You are also more likely to develop macular degeneration if you:
- are overweight
- smoke cigarettes
- are Caucasian
- are female
- have a family history of macular degeneration
- eat a diet high in saturated fat
Approximately 2.07 million Americans had advanced age-related macular degeneration in 2010, and that number is expected to grow to 5.44 million in 2050.
What are Symptoms and Signs of Macular Degeneration?
Macular degeneration usually results in a slow, painless loss of vision. In the early stages, symptoms and signs of macular degeneration can go unnoticed. Early signs of vision loss from macular degeneration include:
- Gradual loss of ability to see objects clearly.
- Shape of objects appear distorted or fuzzy.
- Straight lines look wavy or warped.
- Loss of clear color vision.
- A dark, shadowy or empty area in the center of vision.
What Causes Macular Degeneration?
The exact cause of macular degeneration isn’t known, but the disease is associated with aging. Genetic and environmental factors may also play a role in the development of macular degeneration.
What is it like to See Through Eyes of Someone with Macular Degeneration?
Macular degeneration creates a loss of vision in the center of the eye. You are not able to see fine details, whether you are looking at something close or far. With loss of your central vision, tasks like cooking, reading, and even having a simple conversation with someone can become difficult. Although you lose your central vision, your peripheral (side) vision will still be normal. Early on, straight lines like sidewalks and doorframes will appear to be warped. To get a better understanding of the effect macular degeneration has on sight, use the Vision Loss Simulator at davisvision.com/visionloss.
How is Macular Degeneration Diagnosed?
People do not experience vision loss in the early stages of the disease, making regular eye exams essential for maintaining healthy sight. Eyecare professionals often detect early signs of macular degeneration before symptoms occur. A dilated eye exam can detect macular degeneration, and may include the following:
- Visual acuity test – This eye chart measures how well you see at distances.
- Dilated eye exam – Your eyecare professional will place drops in your eyes to widen or dilate the pupils, which provides a better view of the back of your eye. Using a special magnifying lens, your eyecare professional will then look at your retina and optic nerve for signs of macular degeneration and other eye problems.
- Amsler grid – A brief test using an Amsler grid that measures your central vision may also be performed. Changes in your central vision may cause the lines in the grid to disappear or appear distorted, which is a sign of macular degeneration.
- Fluorescein angiogram – If your eyecare practitioner detects some defect in your central vision, such as distortion or blurriness, he or she may order a fluorescein angiography. In this test, a fluorescent dye is injected into your arm to examine the retinal blood vessels surrounding the macula. Pictures are taken as the dye passes through the blood vessels in your eye. This makes it possible to see leaking blood vessels, which occur in a severe, rapidly progressive type of macular degeneration.
- Optical coherence tomography – This non-invasive test uses light waves to obtain high-resolution images of the eyes.
During the exam, your eyecare professional will look for drusen, the yellow deposits beneath the retina previously discussed. While most people develop some very small drusen as a normal part of aging, the presence of medium-to-large drusen may indicate that you have macular degeneration.
Another sign of macular degeneration is the appearance of pigment changes in the retina. In addition to the pigmented cells in the iris (the colored part of the eye), there are pigmented cells beneath the retina. As these cells break down and release their pigment, your eyecare professional may see dark clumps of released pigment and later, areas that are less pigmented.
How Do You Treat Macular Degeneration?
There is currently no known cure for macular degeneration, but some treatments may delay its progression or even improve vision. No treatments exist yet for dry macular degeneration, however lifestyle changes like dieting, exercise, avoiding smoking, and protecting your eyes from ultraviolet light may help prevent its progression to the wet form. If detected early, wet macular degeneration can be treated with laser treatment, often called photocoagulation. Another option is photodynamic therapy used with FDA-approved drugs aimed at stopping abnormal blood vessel growth.
Davis Vision does not provide medical advice, diagnosis or treatment. More information is available at Site Content & Member Care.