What is Age-Related Macular Degeneration?
Age-Related Macular Degeneration, also known as AMD, is a common eye condition and a leading cause of vision loss among people age 50 and older. It causes damage to the macula, a small spot near the center of the retina and the part of the eye needed for sharp, central vision, which lets us see objects that are straight ahead. In some people, age-related macular degeneration advances so slowly that vision loss does not occur for a long time. In others, the disease progresses faster and may lead to a loss of vision in one or both eyes. As age-related macular degeneration progresses, a blurred area near the center of vision is a common symptom. Over time, the blurred area may grow larger or you may develop blank spots in your central vision.
Age-related macular degeneration by itself does not lead to complete blindness, with no ability to see. However, the loss of central vision in age-related macular degeneration can interfere with simple everyday activities, such as the ability to see faces, drive, read, write, or do close work, such as cooking or fixing things around the house.
- Partial loss of vision
- Abnormality where straight lines appear wavy
- Blurred vision
- Distorted vision
- Inability to see in dim light
- Seeing spots
- Printed words become slightly blurry
- Colors do not seem as bright
- Sometimes you have difficulty recognizing faces
- Your overall vision is becoming hazy
People at Risk for AMD
Age is a major risk factor for age-related macular degeneration. The disease is most likely to occur after age 60, but it can occur earlier. Other risk factors include:
- Smoking. Research shows that smoking doubles the risk of age-related macular degeneration.
- Race. Age-related macular degeneration is more common among Caucasians than among African-Americans or Hispanics/Latinos.
- Family history and genetics. People with a family history of AMD are at higher risk. At last count, researchers had identified nearly 20 genes that can affect the risk of developing age-related macular degeneration. Many more genetic risk factors are suspected.
Does lifestyle make a difference?
Researchers have found links between age-related macular degeneration and some lifestyle choices, such as smoking. You might be able to reduce your risk of age-related macular degeneration or slow its progression by making these healthy choices:
- Avoid smoking
- Exercise regularly
- Maintain normal blood pressure and cholesterol levels
- Eat a healthy diet rich in green, leafy vegetables and fish
The early and intermediate stages of age-related macular degeneration usually start without symptoms. Only a comprehensive dilated eye exam can detect AMD. The eye exam may include the following:
- Visual acuity test. This eye chart measures how well you see at distances.
- Dilated eye exam. Your eye doctor places drops in your eyes to widen or dilate the pupils. This provides a better view of the back of your eye. Using a special magnifying lens, he or she then looks at your retina and optic nerve for signs of AMD and other eye problems.
- Amsler grid. Your eye doctor also may ask you to look at an Amsler grid. Changes in your central vision may cause the lines in the grid to disappear or appear wavy, a sign of AMD.
- Fluorescein angiogram. In this test, which is performed by an ophthalmologist, a fluorescent dye is injected into your arm. 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 AMD (see below). In rare cases, complications to the injection can arise, from nausea to more severe allergic reactions.
- Optical coherence tomography. (OCT) You have probably heard of ultrasound, which uses sound waves to capture images of living tissues. OCT is similar except that it uses light waves, and can achieve very high-resolution images of any tissues that can be penetrated by light—such as the eyes. After your eyes are dilated, you’ll be asked to place your head on a chin rest and hold still for several seconds while the images are obtained. The light beam is painless.
During the exam, your eye care professional will look for drusen, which are yellow deposits beneath the retina. 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 AMD.
Stages of AMD
There are three stages of age-related macular degeneration defined in part by the size and number of drusen under the retina. It is possible to have AMD in one eye only, or to have one eye with a later stage of AMD than the other.
- Early AMD. Early AMD is diagnosed by the presence of medium-sized drusen, which are about the width of an average human hair. People with early AMD typically do not have vision loss.
- Intermediate AMD. People with intermediate AMD typically have large drusen, pigment changes in the retina, or both. Again, these changes can only be detected during an eye exam. Intermediate AMD may cause some vision loss, but most people will not experience any symptoms.
- Late AMD. In addition to drusen, people with late AMD have vision loss from damage to the macula. There are two types of late AMD:
- Dry Age-Related Macular Degeneration, there is a gradual breakdown of the light-sensitive cells in the macula that convey visual information to the brain, and of the supporting tissue beneath the macula. These changes cause vision loss.
- Wet Age-Related Macular Degeneration, abnormal blood vessels grow underneath the retina. These vessels can leak fluid and blood, which may lead to swelling and damage of the macula. The damage may be rapid and severe, unlike the more gradual course of geographic atrophy. It is possible to have both dry and wet age-related macular degeneration in the same eye, and either condition can appear first.
Age-Related Macular Degeneration has few symptoms in the early stages, so it is important to have your eyes examined regularly. If you are at risk for AMD because of age, family history, lifestyle, or some combination of these factors, you should not wait to experience changes in vision before getting checked for AMD. Call or click here to schedule your eye exam today.
Treatment for AMD
As of now, there is no outright cure for age-related macular degeneration, but some treatments may delay its progression or even improve vision.
Treatments for macular degeneration depend on whether the disease is in its early-stage, dry form or in the more advanced, wet form that can lead to serious vision loss. No FDA-approved treatments exist yet for dry macular degeneration, although nutritional intervention may help prevent its progression to the wet form. Our doctors recommend Macular Health vitamins that we sell in our office. Ask your eye doctor if these vitamins are right for you before you purchase.
For more information, please visit American Academy Ophthalmology.