What is Age-Related Macular Degeneration?
Macular degeneration is the leading cause of severe vision loss in people over age 60. It occurs when the small central portion of the retina, known as the macula, deteriorates. The retina is the light-sensing nerve tissue at the back of the eye. Since the symptoms of macular degeneration can become severe as a person ages, it is often referred to as age-related macular degeneration (AMD). Although macular degeneration is almost never a totally blinding condition, it can be a source of significant visual disability.
There Are Two Main Types of Age-Related Macular Degeneration:
The "dry" form is characterized by the presence of yellow deposits, called drusen, in the macula. A few small drusen may not cause changes in vision. However, as they grow in size and increase in number, the drusen can cause symptoms such as dimming or distortion of vision that is noticeable when you read a book.
In more advanced stages, there is also a thinning of the light-sensitive layer of cells in the macula leading to atrophy, or tissue death. In the atrophic form, patients may have blind spots in the center of their vision. In the advanced stages, patients lose central vision.
The wet form is characterized by the growth of abnormal blood vessels from the choroid underneath the macula. This is called choroidal neovascularization. These blood vessels leak blood and fluid into the retina. Once a large amount of blood has entered the retina, you may start to notice signs of vision loss such as wavy lines, blind spots, and loss of central vision. These abnormal blood vessels eventually scar, leading to permanent loss of central vision.
Most patients with symptoms are diagnosed with the dry form of the disease and will not lose central vision. However, the dry form of macular degeneration can lead to the wet form. Although only about 10% of people develop the wet form, they make up the majority of those who experience serious vision loss from the disease.
It is very important for people with macular degeneration to monitor their eyesight carefully and see their eye doctor on a regular basis.
Factors that may increase your risk of encountering the symptoms of macular degeneration include:
- Age - Your risk increases as you age, it is most common in people over age 60.
- Family history - Your odds of developing degeneration are higher if you have a family history of the disease.
- Race - Macular degeneration is more common in Caucasians than it is in other races, especially after age 75.
- Gender - Women are more likely than men to develop degeneration.
- Smoking - Smoking cigarettes increases your risk of encountering the symptoms of macular degeneration.
- Diet - A diet that includes few fruits and vegetables may increase risk.
- High blood pressure - Diseases that affect the circulatory system, such as high blood pressure, may increase the risk.
- High cholesterol - An elevated cholesterol level in your blood is associated with an increased risk.
There are signs that the disease is present in the eye. If you are experiencing any of the following symptoms of macular degeneration you should see an ophthalmologist immediately:
- Straight lines appear wavy
- The center of vision appears distorted but the other areas of vision remain clear
- The center of vision appears dark, white, or blurry
- The ability to perceive colors changes or diminishes
A qualified ophthalmologist can detect signs of macular degeneration during a routine eye examination. Declining vision or a change in the eye’s blood vessels are often indications that eye issues are occurring. Specific questions? Ask our eye care specialists at SEI. Request an appointment at SEI and see what to expect before you visit one of our clinics.
A qualified ophthalmologist can detect signs of macular degeneration during a routine eye examination. Declining vision or a change in the eye’s blood vessels are often indications that eye issues are occurring. Some of the tests done to diagnose macular degeneration may include:
- Dilated Eye Exam and Visual Acuity Test
- Amsler Grid
- Eye Angiogram
There are no cures for dry macular degeneration. There are a few options for treating wet degeneration:
- Outpatient laser surgery - An option for people with more severe wet macular degeneration. The laser beam is used to destroy abnormal blood vessels and slow down the speed of vision loss and other symptoms. Early diagnosis is very important because if the abnormal blood vessels have already grown under the macula, the laser might cause as much damage as the presence of abnormal blood vessels.
- Lucentis - Approved by the FDA in June 2006 for treating the more advanced or "wet" form of macular degeneration, Lucentis (ranibizumab) is a form of the colorectal cancer treatment drug, Avastin. It works by inhibiting proteins called vascular endothelial growth factor (VEGF), which stimulate the growth of new blood vessels in the body. VEGF is thought to contribute to the development of degeneration by promoting the growth of abnormal blood vessels in the retina.
- Eylea - Eylea is designed to inhibit the action of VEGF in wet (neovascular) AMD. It gained FDA approval for this purpose in November 2011.