(AMD)
Definition
Definition
The retina is the tissue that lines the back of the eye. It sends visual signals to the brain. The macula is part of the retina. It is responsible for central vision. Macular degeneration is the most common cause of destruction of the macula in older adults. It causes a gradual loss of sharp, central vision. The condition is mainly a disease of aging. In rare cases, it can occur in younger people.
Macular DegenerationCopyright © Nucleus Medical Media, Inc.
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There are 2 types of adult (or age-related) macular degeneration (AMD):
- Dry AMD—This occurs when an area of the retina becomes diseased. This leads to a slow breakdown of cells in the macula. The central vision is gradually lost. Dry AMD accounts for the majority of cases.
- Wet AMD—As dry AMD worsens, new blood vessels may begin to grow. These new blood vessels often leak blood and fluid under the macula. This can lead to permanent damage of the macular region. Wet AMD is not common. But, it accounts for the majority of blindness from this disease.
Causes
Causes
The cause of AMD is not known.
Risk Factors
Risk Factors
The risk of AMD increases with age. AMD is most commonly seen in women and in people who are Caucasian. Other factors that may increase your chance of getting AMD include:
- Family members with AMD
- Smoking
- Heavy alcohol use
- Excessive exposure to sunlight
- Cardiovascular risks, such as high blood pressure or high cholesterol
- A diet that is low in green, leafy vegetables
Symptoms
Symptoms
In some people, AMD advances slowly. It has little effect on their vision. In others, the disease moves faster. It may lead to significant vision loss. Neither dry AMD nor wet AMD causes pain.
Symptoms may include:
- Blurred vision
- Difficulty seeing details in front of you, such as faces or words in a book
- Blurred vision that goes away in brighter light
- A small, but growing blind spot in the middle of your field of vision
- Straight lines (such as door frames) appear crooked or distorted
Diagnosis
Diagnosis
You will be asked about your symptoms and medical history. A physical exam will be done. AMD may be suspected if you are older and have had recent changes in your central vision. A specialist will look for signs of the disease with an eye exam. Eye drops will be used to dilate (enlarge) your pupils. This will allow a view of the back of the eye.
You may also be asked to view an Amsler grid. This is a pattern that looks like a checkerboard. Changes in your central vision will cause the grid to appear distorted. This is a sign of AMD.
Treatment
Treatment
Talk with your doctor about the best treatment options for you. Options may include:
Dry AMD
Research has suggested certain high-dose vitamins and minerals may slow the progression of the disease in some people.
Wet AMD
Laser Photocoagulation
This procedure is used in some cases of wet AMD. A strong laser light beam is aimed at the new blood vessels. The beam destroys the vessels. It usually takes less than 30 minutes to complete. You may need more laser treatments. This treatment is used less often than newer treatments.
Photodynamic Therapy
This procedure involves injecting a light-sensitive dye into your blood. The affected areas in the back of the eye are then treated with a special laser light. The light activates the dye to destroy certain blood vessels. It takes less than 30 minutes. You may need to have additional treatments.
Vascular Endothelial Growth Factor Inhibitor
Another way to treat wet AMD is an injection of a special medication. It is called a vascular endothelial growth factor (VEGF) inhibitor. The medication is injected into the vitreous (fluid) in the back of the eye. It usually needs to be repeated multiple times.
Prevention
Prevention
There are no current guidelines to prevent AMD. For overall eye health:
- Have regular eye exams. The exams should include dilation to closely look at the retina.
- If you smoke, talk with your doctor about how you can quit.
- Eat a healthy diet that is rich in fruits and vegetables.
- Consider omega-3 fatty acid supplements.
RESOURCES:
Macular Degeneration Foundation http://www.eyesight.org
CANADIAN RESOURCES:
The National Coalition for Vision Health http://www.visionhealth.ca
References:
http://www.ebscohost.com/dynamed
Updated May 7, 2015. Accessed May 26, 2015.
Adult macular degeneration. Macular Degeneration Foundation website. Available at:
http://www.eyesight.org/Macular_Degeneration/Adult_MD/adult_md.html
Accessed May 26, 2015.
Age-related macular degeneration. National Eye Institute website. Available at:
http://www.nei.nih.gov/health/maculardegen/index.asp
Accessed May 26, 2015.
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Last Updated: 5/26/2015