Marshall Flax, the Wisconsin Council of the Blind & Visually Impaired’s Certified Low Vision Specialist, wrote the article below about AMD for our publication The Council Courier. We encourage you to share it with others.
If you or someone you know has AMD, please encourage them to contact the Council at 1-800-783-5213 to learn about the October 18, 2012 macular degeneration symposium we are co-presenting with the University of Wisconsin-Madison Department of Ophthalmology & Visual Sciences.
What is age-related macular degeneration?
Age-related macular degeneration (AMD) is a leading cause of vision loss in Americans 60 years of age and older. It is a disease associated with aging that gradually destroys sharp, central vision. We need central vision to see objects clearly and to perform common daily tasks such as reading and driving.
AMD affects the macula, the part of the eye that allows you to see fine detail. 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 occurs in two forms: wet and dry. It causes no pain.
Where is the macula?
The macula is located in the center of the retina, the light-sensitive tissue at the back of the eye. The retina instantly converts light, or an image, into electrical impulses. The retina then sends these impulses, or nerve signals, to the brain.
What is 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. Damage to the macula occurs rapidly.
With wet AMD, loss of central vision can occur quickly. Wet AMD is also known as advanced AMD. It does not have stages like dry AMD.
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 for a comprehensive dilated eye exam.
What is 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 is gradually lost in the affected eye.
The most common symptom of dry AMD is slightly-blurred vision. You may have difficulty recognizing faces, and 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.
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 still can drive, read, and see fine details. You may notice changes in your vision only if AMD affects both eyes. If blurriness occurs in your vision, see an eye care professional for a comprehensive dilated eye exam.
Ninety percent of all people with AMD have this type. Scientists are still not sure what causes dry AMD.
One of the most common early signs of dry AMD is drusen.
What are 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.
Drusen alone do not usually cause vision loss. In fact, scientists are unclear about the connection between drusen and AMD. They do know that an increase in the size or number of drusen raises a person’s risk of developing either advanced dry AMD or wet AMD. These changes can cause serious vision loss.
Reducing the risk of AMD
Lutein and Zeaxanthin are “nature’s sunglasses.” These are yellow plant pigments found in fruits, vegetables and eggs. They protect and enhance our vision, and research has shown that people with diets rich in these experience fewer cases of AMD. Good sources of Lutein and Zeaxanthin include yellow fruits and vegetables, as well as dark green leafy vegetables like spinach, kale and broccoli.
High levels of vitamin D in the blood are associated with lower rates of early AMD. In the summer, you can obtain this by getting 15 to 30 minutes daily exposure to the sun on your face and hands. Physical activity is also associated with less AMD. One to one and a half hours of daily light activity (like housework or walking) or one hour a day of moderate activity (such as brisk walking) could cut the risk of AMD in half.
Information about age-related macular degeneration was adapted from the National Eye Institute: http://www.NEI.NIH.gov. Details about vitamins and nutrition were provided by Dr. Julie Mares, UW-Madison Department of Ophthalmology and Visual Sciences. She is a popular speaker at “Progress in Sight,” our macular degeneration symposium.
By Wisconsin Council of the Blind & Visually Impaired