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Macular Degeneration: Causes, Symptoms & Treatment
Macular degeneration (MD), the leading cause of blindness among people over 65, is a condition that causes a slow loss of vision capacity. As a result, daily tasks such as driving and reading become more and more difficult for those suffering from macular degeneration.
In later stages of macular degeneration, patients have trouble recognizing faces. Although the condition itself doesn't cause eye pain, the emotional pain of not being able to recognize a loved one is one of the most devastating effects of this condition.
What is Macular Degeneration?
Adults from 40 to 70 years old are at the highest risk for developing macular generation. Scientists believe the disease is a disorder related to the health of blood vessels in the back of the eye. Some say it is also linked to nerve activity in the back of the eye.
Causes of Macular Degeneration
While the precise cause is still under investigation, scientists have established a list of risk factors for macular degeneration, including:
- Age: Age remains the leading risk factor for the development of macular degeneration. As a result, eye health experts encourage people, especially the elderly, to get regular eye exams. Early detection is the best treatment for MD.
- Diet: Because we can't control some of the risk factors for macular degeneration (such as genetic disposition), being mindful of the factors we can control, such as diet, is increasingly important. While it is widely known that vitamins A & E (as well as beta carotene and zinc) are important to maintaining healthy eyes, scientists are also studying the effects of lutein and omega-3 fatty acids on eye health.
Recent studies are also finding promising effects from the antioxidant properties of vitamin C. Consequently, companies are developing nutritional supplements specifically designed to promote eye health.
- Genes: Heredity is one risk factor for macular degeneration over which we have little control. Recently, scientists discovered a specific gene (complement factor B) that islinked to the onset of macular degeneration. This discovery is raising hopes for the development of new, cutting-edge treatments for the disease.
- High Blood Pressure: Recent studies have linked high blood pressure to the development of macular degeneration.
- Lighter Eye Color: People with lighter eye colors, such as blues and light greens, lack pigments that prevent intense, brighter light from entering the eye. Although results are still inconclusive, some research has indicated that this increased exposure to light contributes to the onset of MD.
- Smoking: Along with causing a host of other diseases and conditions, smoking also contributes to the onset of MD. According to the Encyclopedia Britannica, two recent American studies found that people who smoke a pack a day have more than twice the risk of developing age-related macular degeneration than non-smokers.
Early detection of macular degeneration gives a patient more treatment options. For this reason, getting regular eye exams is extremely important.
Symptoms of Macular Degeneration
Symptoms associated with macular degeneration include:
- blurred vision (Depending on the exact type of macular degeneration, this may occur slowly, or as quickly as a few weeks.)
- difficulty distinguishing colors
- distorted vision
- scotomas (areas of missing vision)
- trouble returning to normal vision after seeing bright light.
Dry & Wet Macular Degeneration
There are two main types of age-related macular degeneration:
- Dry Macular Degeneration: In dry macular degeneration, waste products from the eye's photoreceptors accumulate in the tissue layer underneath the retina or on the head of the optic nerve. The wastes appear as yellow or off-white spots called drusen.
The visual changes in dry macular degeneration correlate with the loss of function of corresponding areas of the retina. Dry macular degeneration accounts for 90 percent of macular degeneration cases.
- Wet Macular Degeneration: Wet macular degeneration is a less common type of macular degeneration. It tends to develop quickly and causes rapid vision loss. In wet macular degeneration, new blood vessels form under the retina. These new vessels are delicate and soon begin to leak blood and fluid, distorting the macula and compromising central vision.
Treatment for Macular Degeneration
Currently, the most common macular degeneration treatment is laser photocoagulation. Although this procedure doesn't entirely restore vision, it wards off debilitating symptoms of MD by sealing blood vessels in the eye.
Unfortunately, laser photocoagulation is a controversial treatment. During the process, lasers are used to destroy unwanted blood vessels. However, the beam also burns photoreceptors positioned above the blood vessels, creating areas of distorted or completely missing vision.
Laser photocoagulation is really a trade off for patients. They can either have the treatment and risk scotomas or continue suffering from macular degeneration, possibly losing all their vision in a short period of time.
Photodynamic therapy (PDT) is an alternative to photocoagulation. This treatment uses a dye injection to identify damaged blood vessels. Doctors then use a more precise laser to seal the individual damaged vessels, sparing the photoreceptors.
The only known drawback to this procedure is that patients must remain completely out of the sun for several days after the treatment.
Several drugs and vitamin supplements are also in the works to treat macular degeneration. However, approval from the Food and Drug Administration of these products is still at least a few years away.
