What is Macular Degeneration?

Macular degeneration is a retinal degenerative disease that causes progressive loss of central vision. The risk of developing macular degenerationincreases with age. The disease most often affects people in their sixties and seventies. Macular degeneration is the most common cause of vision loss in individuals over the age of fifty-five.

Clinical Description

Central vision loss from macular degeneration is caused by the degeneration of the macula. The macula is the central portion of the retina responsible for perceiving fine visual detail. Light sensing cells in the macula, known as photoreceptors, convert light into electrical impulses and then transfer these impulses to the brain via the optic nerve. Central vision loss from macular degenerationoccurs when photoreceptor cells in the macula degenerate.

Illustrated cross section of an eye

Individuals with macular degeneration may first notice a blurring of central vision that is most apparent when performing visually detailed tasks such as reading and sewing. Blurred central vision may also make straight lines appear slightly distorted or warped. As the disease progresses, blind spots form within central vision. In most cases, if one eye has macular degeneration, the other eye will also develop the disease. The extent of central vision loss varies according to the type of macular degeneration.

A simulated image of normal vision
Normal vision
A simulated image what someone with macular degeneration sees
Picture as seen by someone who has macular degeneration

*Images courtesy of the National Eye Institute, NIH

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What Causes Macular Degeneration?

Early onset forms of macular degeneration are genetic — programmed into your cells and not caused by injury, infection or any other environmental factors. Certain genes necessary for normal vision give faulty messages to the cells in the macula, which leads to their progressive degeneration and eventual loss of vision.

Macular degeneration, is the leading cause of vision loss in adults over the age of 55. Studies have found that both genetic and environmental risk factors influence the disease.

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What Are Some of the Questions I Should Ask My Eye Doctor?

  1. What changes can I expect in my vision?
  2. Will my vision loss get worse? How much of my vision will I lose?
  3. Will regular eyeglasses improve my vision?
  4. What medical/surgical treatments are available for my condition?
  5. What can I do to protect or prolong my vision?
  6. Will diet, exercise, or other lifestyle changes help?
  7. If my vision can't be corrected, can you refer me to a specialist in low vision?
  8. Where can I get a low vision examination and evaluation? Where can I get vision rehabilitation?
  9. What is the name of my eye condition?
  10. What is my visual acuity (Central vision)?
  11. What is my visual field (Side vision)?
  12. Are there other tests?
  13. What about a second opinion?
  14. Are there any optical or non-optical aids that can help me use my remaining vision to the fullest extent possible?
  15. Are there any mobility aids to help me move around more safely?
  16. Do any of your other patients have this condition? Would they be willing to talk with my family and me?
  17. Do you have any educational materials that describe this condition?
  18. Are there any organizations that provide services to individuals with this or related eye conditions?

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Input from the National Eye Institute

What Are the Symptoms of Macular Degeneration?

  • Blurring of Central Vision
  • Difficulty Seeing Detail — Up Close and at a Distance
  • Distortion of Lines and Shapes
  • Diminished Color Vision

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Can my Ophthalmologist Diagnose Macular Degeneration?

Possibly, however, if you experience either of the symptoms noted above and your ophthalmologist isn’t certain, you should consult with a retinal specialist. The Foundation maintains a list of doctors who specialize in retinal degenerative diseases.

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Are There Special Tests to Diagnose Macular Degeneration?

Yes.

Your doctor will examine your eyes with special lenses to view the interior of the eye through the pupil. Other tests for Macular Degneration include:

Acuity Tests: This test measures the accuracy of your central vision at specific distances in specific lighting situations.

Amsler Grid Test: This test checks for spots of sight loss.

Color Testing: This can help determine the status of your cone cells, the retinal cells that interpret color.

Fluorescein Angiogram Test: This test allows your doctor to visualize the inner structure of the eye. Photos are taken of the retina and the macula in order to identify new blood vessel growth and leakage from blood vessels.

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Can Macular Degeneration Lead to Total Blindness?

Most people with macular degneration retain peripheral vision and learn to optimize the use of their remaining vision. Legally blind individuals are those whose best visual acuity or sharpness (with glasses or contact lenses, if needed) is 20/200 or worse in their better eye; or whose visual field, regardless of acuity, is restricted to a 20 degree diameter (10 degree radius).

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Can Macular Degeneration be Prevented?

At present, there is no known way to prevent macular degneration. For now, the most important thing to do is to have regular eye exams, which may allow early detection and diagnosis. This is particularly important if a close relative has been diagnosed with macular degneration.

There are also several areas of research that offer tremendous promise for halting the disease or restoring vision loss:

  • Retinal Cell Transplants
  • Pharmaceutical therapy
  • Nutritional Therapy
  • Gene Therapy

For additional information on these or any other areas of our research, please scroll back to the Home Page or to the Master macular degneration page.

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Is there a Treatment for Macular Degeneration?

Laser photocoagulation can help some people with wet macular degneration. In this treatment, laser light rays are directed into the eye and focused on a small spot on the macula. The laser destroys the blood vessels growing beneath the retina and seals leaky areas. This treatment does not restore lost vision, so it is critical that is be applied as early as possible before vision loss has progressed significantly. There are also several experimental treatments being evaluated in clinical trials.

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How Quickly Does Macular Degeneration Progress?

It’s different for every patient, however, wet AMD progresses more quickly than dry AMD.

  • Are There Any Special Risk Factors for Macular Degeneration?

Potentially,

  • History of hypertension
  • History of cardiovascular disease
  • Smoking
  • Sun Exposure
  • Hyperopis (farsightedness)
  • Light Skin & Eye Color
  • Lens Opacities (cataracts)

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If I have Drusen, Does that Mean I’ll Develop Macular Degeneration?

Not necessarily. Drusen are deposits that contain complex lipids (fats) and calcium that can accumulate as a person ages. Many people have drusen in both eyes and have no vision impairment. If your eye doctor detects drusen in your eyes, you should continue to seek eye care regularly and use an Amsler Grid to monitor your vision.

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Can an Eye Transplant Cure Macular Degeneration?

No. Medical technology is not yet advanced enough to transplant the entire eye.

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Are Cataracts Associated with Macular Degeneration?

No, however, it is not unusual for an older person with macular degneration to also develop cataracts, which is a clouding of the lens of the eye.

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What Is Wet Macular Degeneration?

Wet macular degneration accounts for about 10 percent of cases. Wet macular degneration is also called choroidal neovascularization, subretinal neovascularization, exudative, or disciform degeneration. In wet macular degneration, abnormal blood vessel growth forms beneath the macula. These vessels leak blood and fluid into the macula damaging photoreceptor cells. Wet macular degnerationtends to progress rapidly and can cause severe damage to central vision.

In some cases, if wet macular degneration is diagnosed early, laser surgery can prevent extensive central vision loss. In this type of surgery, laser beams destroy the leaky blood vessels that form beneath the macula. For laser surgery to be effective, it is critical that wet macular degeneration be diagnosed before extensive vision loss occurs. Therefore, individuals should consult with an eye doctor at the first sign of blurred or distorted central vision. Doctors are also conducting clinical trials to test experimental treatments. If you are diagnosed with wet macular degneration, you may want to ask your doctor about these treatments.

For more information on macular degneration, visit www.maculardegeneration.org.

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What Is Dry Macular Degeneration?

Dry macular degeneration accounts for about 90 percent of all cases. Dry macular degeneration is sometimes called atrophic, nonexudative, or drusenoid macular degeneration. With dry macular degeneration, yellow-white deposits called drusen accumulate in the retinal pigment epithelium (RPE) tissue beneath the macula. Drusen deposits are composed of waste products from photoreceptor cells. For unknown reasons, RPE tissue can lose its ability to process waste. As a result, drusen deposits accumulate in the RPE. Drusen deposits are typically present in patients with dry macular degeneration. These deposits are thought to interfere with the function of photoreceptors in the macula, causing progressive degeneration of these cells. Drusen deposits can, however, be present in the retina without vision loss.

Vision loss from drymacular degeneration occurs very gradually over the course of many years. Central vision may even remain stable between annual eye examinations. Individuals withmacular degeneration do not usually experience a total loss of central vision. However, vision loss may make it difficult to perform tasks that require finely focused vision. Although there are extensive research efforts to find treatments for dry macular degeneration, at this time no proven treatments exist.

For more information on macular degeneration, visit www.maculardegeneration.org.

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