Macular Degeneration - Defined
Age-related macular degeneration, also known as AMD, is an eye disease that affects the macula, a part of the retina. The retina sends light from the eye to the brain, and the macula allows you to see fine detail.
AMD blurs the sharp central vision you need for straight-ahead activities such as reading, sewing, and driving. AMD causes no pain.
In some cases, AMD advances so slowly that people notice little change in their vision. In others, the disease progresses faster and may lead to a loss of vision in both eyes. AMD is a leading cause of vision loss in Americans 60 years of age and older.
There are two forms of age-related macular degeneration -- dry and wet.
AMD Defined - Wet AMD
Wet AMD occurs when abnormal blood vessels behind the retina start to grow under the macula. These new blood vessels tend to be very fragile and often leak blood and fluid. The blood and fluid raise the macula from its normal place at the back of the eye.
An early symptom of wet AMD is that straight lines appear wavy. If you notice this condition or other changes to your vision, contact your eye care professional at once. You need a comprehensive dilated eye exam.
With wet AMD, loss of central vision can occur quickly. Wet AMD is considered to be advanced AMD and is more severe than the dry form.
AMD Defined - Dry AMD
Dry AMD occurs when the light-sensitive cells in the macula slowly break down, gradually blurring central vision in the affected eye. As dry AMD gets worse, you may see a blurred spot in the center of your vision. Over time, as less of the macula functions, central vision in the affected eye can be lost gradually.
The most common symptom of dry AMD is slightly blurred vision. You may have difficulty recognizing faces. You may need more light for reading and other tasks. Dry AMD generally affects both eyes, but vision can be lost in one eye while the other eye seems unaffected.
One of the most common early signs of dry AMD is drusen. Drusen are yellow deposits under the retina. They often are found in people over age 60. Your eye care professional can detect drusen during a comprehensive dilated eye exam.
Dry AMD has three stages -- early AMD, intermediate AMD, and advanced dry AMD. All of these may occur in one or both eyes.
People with early dry AMD have either several small drusen or a few medium-sized drusen. At this stage, there are no symptoms and no vision loss.
People with intermediate dry AMD have either many medium-sized drusen or one or more large drusen. Some people see a blurred spot in the center of their vision. More light may be needed for reading and other tasks.
In addition to drusen, people with advanced dry AMD have a breakdown of light-sensitive cells and supporting tissue in the macula. This breakdown can cause a blurred spot in the center of your vision.
Over time, the blurred spot may get bigger and darker, taking more of your central vision. You may have difficulty reading or recognizing faces until they are very close to you.
If you have vision loss from dry AMD in one eye only, you may not notice any changes in your overall vision.
With the other eye seeing clearly, you can still drive, read, and see fine details. You may notice changes in your vision only if AMD affects both eyes. If you experience blurry vision, see an eye care professional for a comprehensive dilated eye exam.
The information provided should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies.
Copyright Information: Public domain information with acknowledgement given to the U.S. National Library of Medicine.