Macular Degeneration

Definition

Macular degeneration is damage to or breakdown of the macula of the eye. The macula is a small area at the back of the eye that allows us to see fine details clearly. Macular degeneration makes close work like threading a needle or reading a book, difficult or impossible. When the macula doesn't function correctly, we experience blurriness or darkness in the center of our vision. Although macular degeneration reduces vision in the central part of the retina, it does not affect the eye's side or peripheral vision. For example, you could see a clock but not be able to tell what time it is. Macular degeneration alone does not result in total blindness. Most people continue to have some useful vision and are able to take care of themselves.

There are two forms of macular degeneration:

The Dry Type
This is the most common form. In this type of macular degeneration, the delicate tissues of the macula become thinned and cease to function properly.
The Wet Type
This is less common, but is typically more damaging. The wet type of macular degeneration is caused by the growth of abnormal blood vessels behind the macula. The abnormal blood vessels tend to hemorrhage or leak, with the result being the formation of scar tissue if left untreated. In some instances, the dry type of macular degeneration can turn into the wet type.

Macular degeneration develops differently in each person. Because it will affect different regions of the macula from person to person, the symptoms tend to vary. Macular degeneration causes a progressive loss of central sight, however, it does not cause total blindness. Peripheral vision is unaffected allowing a certain amount of mobility in normal surroundings. If left untreated, the wet type of macular degeneration may progress rapidly.

Symptoms

  • The loss of the ability to see objects clearly
  • Vision that is noticeably distorted
  • Straight lines appear wavy
  • Objects may appear as the wrong shape or size
  • The loss of clear, correct colors
  • Difficulty reading or seeing objects up close
  • A dark, empty area in the center of vision

The symptoms described above may not necessarily mean that you have macular degeneration. However, if you experience one or more of these symptoms, contact your eye doctor for a complete exam.

Treatment

For an individual with macular degeneration, it is highly recommended that a regular schedule of eye examinations be maintained. During these examinations, detailed documentation is made through photographs and fluorescein angiography scans of the health of the retina. With this information, your eye doctor is better able to monitor the condition and note any changes that may occur.

Treatment for Dry Macular Degeneration

There is no form of treatment that is known to stop the progression of this type of macular degeneration, although vitamin supplements are often prescribed. Once the retinal tissues are affected, there is little that can be done to stop its slow progression and currently, nothing has been found effective to restore the loss of sight.

Treatment for Wet Macular Degeneration

The newest treatment for wet AMD is Lucentis, a drug that was approved by the FDA in 2006. This drug inhibits the growth and leakage of abnormal blood vessels and it is the first treatment that has been shown to improve vision in some eyes rather than simply slowing the rate of vision loss. Lucentis is delivered through tiny injections in the eye, once a month for three months, with additional, less frequent injections, as needed, for one year or more. A similar drug, Avastin, is also commonly used for the treatment of wet AMD.

Other treatments include laser treatments and photodynamic therapy. These treatments are designed to seal the leaking blood vessels, halting the damage they can inflict upon the retina. These treatments are effective in slowing the progression of wet macular degeneration and are sometimes used in combination with Lucentis or Avastin. Research is underway to find new and more effective treatments for this condition.

Additional Resources

These websites are not operated by the University of Michigan Kellogg Eye Center. Kellogg Eye Center is not associated with these websites in any way, nor does it endorse or take responsibility for any of the content. These links are provided for the convenience of our users.

American Academy of Ophthalmology

Canadian Ophthalmological Society

MedlinePlus

National Institutes of Health

  • ARMD
    NIH's SeniorHealth website covers the topic of Age-Related Macular Degeneration

National Eye Institute

American Foundation for the Blind - Senior Site

  • Macular Degeneration
    Basic information about AMD and low vision; includes a self-test using an Amsler Grid

Journal of the American Medical Association (JAMA)

WebMD

LightHouse International

  • Macular Degeneration
    Provides a general overview of the basics of AMD, and a simulation showing a scene as it might be viewed by a person with AMD

Prevent Blindness America

Foundation Fighting Blindness

Clinic Information

For more information, see the Retina and Uveitis Clinic and the complete Clinic Services listing of the U-M Kellogg Eye Center.

Last Modified: Wednesday, 19-Feb-2014 08:42:44 EST