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Adult Macular Degeneration

(Age-Related Macular Degeneration, AMD)

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.

Adult, or age-related macular degeneration (AMD), is classified as:

  • Early—The presence of medium-sized drusen indicate early AMD. Drusen are yellow deposits found under the retina. Vision is not affected.
  • Intermediate—Large drusen are present, with out without changes in the pigment of the retina. Vision loss may occur, but most people do not have symptoms.
  • Late—Vision loss and macular damage are present, along with drusen. Late AMD can be:
    • Dry—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—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.

Macular Degeneration

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Causes  ^

The cause of AMD is not known. It may be related to a combination of genetics and environmental exposures over the course of a lifetime.

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:

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. AMD does not cause 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  ^

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.

Imaging tests may be used in some cases. These may include:

  • Angiography—a dye is used to make blood vessel easier to see
  • Optical coherence tomography (OCT)

Treatment  ^

Treatment depends on the stage of AMD. In general, lifestyle changes will help slow disease progression for early, intermediate, and late (dry) stages:

  • Dietary changes—Include more green, leafy vegetables (for vitamins and minerals) and fish (for omega-3 fatty acids) in your diet. If you have trouble with meal planning, talk to a registered dietitian.
  • Vitamin and mineral supplements have been found to help slow the progression of AMD. Your doctor may advise increasing your intake of certain vitamins and minerals, including vitamins C and E, beta carotene, zinc, and copper.
  • If you smoke, your doctor will work with you on ways to successfully quit. Smoking is associated with AMD development and progression.

Your doctor will schedule regular exams to monitor any changes or progression in AMD.

Late (Wet) AMD

Vision loss at this stage can be severe. Options to slow vision loss include:

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  ^

To help reduce your chance of AMD:

  • Have regular eye exams as suggested by your eye doctor.
  • If you smoke, talk with your doctor about how you can quit.
  • Eat a healthy diet that is rich in fruits and green, leafy vegetables.
  • Talk to your doctor about taking what, if any, vitamin and mineral supplements you should take.
RESOURCES:

American Macular Degeneration Foundation
https://www.macular.org

Macular Degeneration Foundation
http://www.eyesight.org

CANADIAN RESOURCES:

AMD Alliance International
http://www.amdalliance.org

Canadian Association of Optometrists
https://opto.ca

REFERENCES:

Adult macular degeneration. Macular Degeneration Foundation website. Available at: http://www.eyesight.org/Macular_Degeneration/Adult_MD/adult_md.html. Accessed May 4, 2016.

Age-related macular degeneration (AMD). EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated May 7, 2015. Accessed May 4, 2016.

Age-related macular degeneration (AMD). National Eye Institute (NEI) website. Available at: https://nei.nih.gov/health/maculardegen. Updated September 2015. Accessed May 4, 2016.

Rosenfeld PJ, Brown DM, Heier JS, et al. Ranibizumab for neovascular age-related macular degeneration. N Engl J Med. 2006;355(14):1419-1431.

11/1/2007 DynaMed's Systematic Literature Surveillance. Available at: http://www.ebscohost.com/dynamed: Wormald R, Evans J, Smeeth L, Henshaw K. Photodynamic therapy for neovascular age-related macular degeneration. Cochrane Database Syst Rev. 2005;(4):CD002030.

3/6/2013 DynaMed's Systematic Literature Surveillance. Available at: http://www.ebscohost.com/dynamed: Sui GY, Liu GC, Liu GY, et al. Is sunlight exposure a risk factor for age-related macular degeneration: A systematic review and meta-analysis. Br J Ophthalmol. 2013;97(4):389-394.

3/11/2013 DynaMed's Systematic Literature Surveillance. Available at: http://www.ebscohost.com/dynamed: Christen WG, Glynn RJ, Sesso HD, et al. Vitamins E and C and medical record-confirmed age-related macular degeneration in a randomized trial of male physicians. Ophthalmology. 2012;119(8):1642-1649.

6/17/2014 DynaMed's Systematic Literature Surveillance. Available at: http://www.ebscohost.com/dynamed: Chew EY, Clemons TE, Agrón E, et al. Ten-year follow-up of age-related macular degeneration in the age-related eye disease study: AREDS report no. 36. JAMA Ophthalmol. 2014;132(3):272-272.

Last reviewed May 2016 by Michael Woods, MD