Age related macular degeneration (AMD) is a common eye condition among people age 50 and older. It is a leading cause of vision loss in older adults. It gradually destroys the macula, the part of the eye that provides sharp, central vision needed for seeing objects clearly. Despite the limited vision, AMD does not cause complete blindness. You will be able to see using your side (peripheral) vision.
Macular degeneration is a disease of the macula - a small area in the retina at the back of the eye. It is a deterioration related to aging of the center part of the retina. Thus, it reduces the central part of the field of vision as opposed to the peripheral vision.
The macula allows an individual to see fine details clearly and judge distances accurately (read and drive). When the macula does not work properly, the central vision is blurry with possible dark or distorted areas. Macular degeneration affects our ability to judge close distance activities like threading a needle, making it very difficult or impossible.
Although macular degeneration reduces vision in the central part of the retina, it usually does not affect the peripheral vision and usually does not cause total blindness. Even in more advanced cases, people usually continue to have some useful vision and maintain their independence.
Major risk factors for macular degeneration are:
- Age: 50 and older
- Being of Caucasian ancestry
- Family history of macular degeneration
- Cigarette smoking
- Abnormal cholesterol levels
- Large drusen (waste) deposits under the retina
Macular degeneration is the most common cause of severe vision loss in Caucasians older than 50. It is called age-related macular degeneration or AMD. It is a result of the human body, over time, reacting to oxygen in the environment and producing molecules called free radicals. The free radicals damage cells resulting in oxidative stress.
There are two common types of macular degeneration:
- dry (non-neovascular)
- wet (neovascular)
Dry Macular Degeneration is caused by damage (oxidative stress) and results in thinning of macular tissue. Vision loss is usually gradual and is identified by difficulty adjusting to changes in light (coming indoors from outdoors).
There is no form of treatment that is known to stop the progression of dry macular degeneration, although dietary changes and vitamin supplements are often recommended.
The National Eye Institute sponsored a study called Age-Related Eye Disease Study 2 to access the effects of oral and nutritional supplements with regard to the progression of advanced macular degeneration.
Wet Macular Degeneration results from abnormal blood vessels forming underneath the retina. The new blood vessels leak fluid or blood and blur central vision rapidly and severely.
Some drugs for the treatment of wet macular degeneration have been found to not only slow the rate of vision loss, but to actually improve vision in some eyes. Other treatments can involve laser treatments and photodynamic therapy.