Age-Related Macular Degeneration (AMD)
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What is Age-related Macular Degeneration?
Age-related macular degeneration (AMD) is a disease associated with aging that gradually destroys sharp, central vision. Central vision is needed for seeing objects clearly and for common daily tasks such as reading and driving. AMD affects the macula, the part of the eye that allows you to see fine detail. Although AMD is a leading cause of vision loss in Americans 60 years of age and older, there is no pain associated with the disease, which occurs in two forms: wet and dry.
What Are The Forms Of 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, causing rapid damage to the macula.
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.
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.
Who Is At Risk For AMD?
- Age: The greatest risk factor is age, people over age 60 are at greater risk than other age groups.
- Smoking: Smoking may increase the risk of AMD.
- Obesity: Research studies suggest a link between obesity and the progression of early and intermediate stage AMD to advanced AMD.
- Race: Whites are much more likely to lose vision from AMD than African Americans.
- Family history: Those with immediate family members who have AMD are at a higher risk of developing the disease.
- Gender: Women appear to be at greater risk than men.
Can My Lifestyle Make A Difference?
Your lifestyle can play a role in reducing your risk of developing AMD. Studies have shown that by following a few simple steps you can greatly reduce the risk of AMD.
- Eat a healthy diet high in green leafy vegetables and fish.
- Don't smoke.
- Maintain normal blood pressure.
- Watch your weight.
What Are The Symptoms Of AMD?
Symptoms of Wet AMD
The classic early symptom for wet AMD is that straight lines appear crooked. This results when fluid from the leaking blood vessels gathers and lifts the macula, distorting vision. A small blind spot may also appear in wet AMD, resulting in loss of one's central vision.
Symptoms of Dry AMD
The most common early sign for dry AMD is blurred vision. As fewer cells in the macula are able to function, people will see details less clearly in front of them, such as faces or words in a book. Often this blurred vision will go away in brighter light. If the loss of these light-sensing cells becomes great, people may see a small--but growing--blind spot in the middle of their field of vision.
How is AMD Detected?
At the Woodlands Retina Center, we can detect AMD by conducting an eye exam that may include some or all of the following:
- Visual acuity test
- Dilated eye exam
- Amsler Grid Testing
- Fluorescein angiogram
Treatment of AMD
How is Wet AMD Treated?
There are several treatment options available for the treatment of Wet AMD. At The Woodlands Retina Center we will tell you which of the following treatment options suits your condition best:
- Laser surgery
- Photodynamic therapy
How is Dry AMD Treated?
Once dry AMD reaches the advanced stage, no form of treatment can prevent vision loss. However, treatment can delay and possibly prevent intermediate AMD from progressing to the advanced stage, in which vision loss occurs. Slowing AMD's progression from the intermediate stage to the advanced stage can save the vision of many people.
How can I take care of my vision now that I have AMD?
If you have dry AMD, you should have a comprehensive dilated eye exam at least once a year. If you have intermediate AMD in one or both eyes, or advanced AMD in one eye only, your doctor can recommend ways to prevent or delay deterioration of vision in the other eye.
Because dry AMD can turn into wet AMD at any time, you should learn how to use an Amsler grid. Use the grid every day to evaluate your vision. If you detect any changes, schedule an eye exam immediately.
How to Use an Amsler Grid
In between your visits you can continue to monitor your vision using an Amsler Grid. This diagnostic tool helps detect visual disturbances caused by AMD. It is used to monitor central vision. If
you detect any changes in your vision report it to your doctor.
The Amsler grid is made up of vertical and horizontal lines with a small dot at the center. In the test, the person looks with each eye separately at the small dot in the center of the grid. Patients with AMD may see distorted wavy lines or missing lines.
A normal Amsler Grid looks like this:
This is what an abnormal Amsler Grid may look like:
Click here to get a printable Amsler Grid that you can use to monitor your vision and directions for how to use it.
Further Information on AMD
AMD is the leading cause of vision loss in Americans aged 60 years and above. This has lead to alot of research and studies being carried out in the field of diagnosis, prevention and treatment of
AMD. The following links may contain useful information for your benefit
- AMD Alliance International
- Home of The Association for Macular Diseases and The Macula Foundation
- Macular Degeneration Foundation
- Macular Degeneration Partnership