Macular degeneration is also known as age-related macular degeneration, AMD, or ARMD. This condition occurs when the central portion of your retina, the macula, wears down, resulting in vision loss.
Your macula is responsible for focusing central vision in the eye. It controls your ability to:
- Read
- Drive
- Recognize faces and colors
- See objects in refined detail
When the cells of your macula deteriorate, you begin to lose central vision but retain peripheral vision. The prevalence and severity of AMD increase with age.
Macular degeneration is one of the leading causes of vision loss. It affects over 10 million Americans. It is most present in Caucasians.
Causes of Macular Degeneration
AMD is a little-understood disease. The exact cause of macular degeneration is still unknown. Researchers believe there are genetic components and environmental factors that may affect your susceptibility to AMD.
AMD Risk Factors
- Age. The most prominent risk factor is aging, and most cases of AMD occur in people over 50.
- Family history. Researchers have identified certain genes related to the development of AMD.
- Race. Caucasians have a higher risk of AMD.
- Smoking. Smoking or being exposed to second-hand smoke increases your chances of developing AMD.
- Unhealthy Diet. Research suggests obesity and unhealthy diets may increase the severity of AMD.
- Cardiovascular disease. You may be more likely to develop a wet form of macular degeneration if you have conditions that affect your heart or blood vessels, such as high blood pressure.
Types of Macular Degeneration
There are two types of macular degeneration: dry (non-exudative) and wet (exudative). Most cases, 80 to 90 percent, of all AMD are the dry form.3 Here are their differences:
Dry Macular Degeneration
People with dry AMD will develop yellow deposits, called drusen, in their macula. At first, a few small drusen may not affect your vision. However, as they increase in size and number, they may cause visual distortion or dimness, especially while reading.
As the eye disease progresses, the light-sensitive cells in your macula wear away and eventually die. This can cause blind spots in the center of your vision. It may ultimately result in the loss of central vision.
Wet Macular Degeneration
In wet AMD, the blood vessels underneath your macula begin to leak blood and other fluids into the back of the eye. This distorts your vision and causes straight lines to appear wavy.
Eventually, these abnormal blood vessels and their fluids will form scars. This results in permanent central vision loss. Wet AMD often results in more severe vision loss than dry cases.
Stargardt Disease
In rare cases, AMD will develop in children or teenagers. This is known as Stargardt disease. While Stargardt disease is similar to AMD, it is thought to be caused entirely by genetics.
3 Stages of Macular Degeneration
There are three stages of macular degeneration:
1. Early AMD
Most people do not experience vision loss in the early stage. An eye doctor can diagnose early AMD during an eye exam by spotting medium-sized drusen (yellow deposits) in the macula.
2. Intermediate AMD
In this stage, there is usually some vision change or loss. However, not everyone will experience vision problems yet. Optometrists will perform an eye examination to look for larger drusen or pigmentation changes in the retina.
3. Late AMD
During late AMD, vision loss has become noticeable. There may be permanent thinning or scarring of cells.
Symptoms of Macular Degeneration
In the early stages of AMD, you may not recognize any symptoms. They often go unnoticed until both eyes are affected, or your eyesight deteriorates significantly.
Signs of AMD include:
- Need for brighter lighting to read
- Blurring of printed words
- Straight lines appearing bent or wavy
- Dark or blurry areas in the center of your vision
- Difficulty recognizing faces
- Reduced brightness or intensity of colors
When to See a Doctor
Schedule an eye exam immediately if you experience any of these symptoms. Undergo an annual eye examination, especially after age 50, to maintain proper eye health.
How is AMD Diagnosed?
AMD is diagnosed during a complete eye examination. If you are at risk for AMD, they may perform one or more tests to check for signs of macular degeneration:
Amsler grid
Your optometrist may ask you to look at an Amsler grid. This will test for deficiencies in your central vision. If some of the straight lines in the grid appear wavy, broken, or faded, this may be a sign of macular degeneration.
Retinal Examination
Your eye doctor may dilate your eyes by administering eye drops. They will then use a special instrument to examine the back of your eye. They will look for drusen, the yellow deposits that form under the retina. These are a sign of macular degeneration.
Fluorescein angiography
This involves your doctor injecting a colored dye into your arm. The dye travels to the blood vessels in your eye. A camera will take several pictures as the dye highlights the blood vessels. The images will reveal if you have abnormal blood vessels or changes in your retina.
Optical coherence tomography
This non-invasive imaging procedure will take detailed cross-sectional images of your retina. It will identify areas of retinal thinning, thickening, or swelling.
While doctors are not entirely sure of AMD's causes, there are certain preventative measures you can take to decrease the risk of developing severe macular degeneration in the future, including:
- Manage other medical conditions. See your doctor and follow their treatment regimen for any other medical condition, especially cardiovascular diseases.
- Don’t smoke. Smoking increases your chances of AMD significantly.
- Maintain a healthy diet. A balanced diet filled with antioxidants and omega-3 fatty acids may reduce your risk of developing AMD.
- Maintain a healthy weight. Exercise regularly and maintain a proper diet. Obesity is a risk factor for AMD.
Macular Degeneration Treatment Options
There is no known cure for macular degeneration. For dry AMD, there are no U.S. Food and Drug Administration (FDA)-approved treatments. However, there are many treatment options, depending on the type and severity of your condition.
Nutritional Therapy
The Age-Related Eye Disease Study (AREDS) by the National Eye Institute (NEI), has found that, in clinical trials, nutritional supplements have benefited people with intermediate or late AMD.
The original AREDS formula contains:
| Nutrient | Amount |
|---|---|
| Vitamin C | 400 mg |
| Vitamin E | 400 IU |
| Beta-carotene | 15 mg |
| Copper (cupric oxide) | 2 mg |
| Zinc | 80 mg |
The AREDS2 formula was modified to remove beta-carotene, which increased smokers’ chances of lung cancer:
| Nutrient | Amount |
|---|---|
| Vitamin C | 400 mg |
| Vitamin E | 400 IU |
| Copper (cupric oxide) | 2 mg |
| Lutein | 10 mg |
| Zeaxanthin | 2 mg |
| Zinc | 80 mg |
The vitamins C and E, beta-carotene, zinc, copper, lutein, zeaxanthin, and omega-3 fatty acids have all been linked to reducing the risk of vision loss.
Your doctor may prescribe nutritional supplements containing antioxidant vitamins. These can help combat the progression of AMD.
Photodynamic Therapy
Laser therapy can reduce the progression of wet AMD. In this treatment, an ophthalmologist injects a dye to guide the laser to the affected areas. The procedure seals off leaking blood vessels and leaves healthy ones alone.
However, laser therapy has not proven successful long-term, and this procedure will likely need to be repeated.
Anti-VEGF Therapy
Anti-VEGF drugs are currently the most common and effective treatment for AMD. VEGF stands for vascular endothelial growth factor. This drug is injected into the eye and stimulates the growth of new blood vessels.
This procedure takes approximately 15 minutes. It has shown great potential in slowing down and even preventing macular degeneration progression.
Low-Vision Aids
Low-vision devices improve vision for people who suffer from poor vision. They can be optical, non-optical, or electronic. There are several instruments and techniques available.
Summary
Macular degeneration is a condition that affects your retina. It wears down your retina over time, and it can eventually result in vision loss. While no cure is available for macular degeneration, there are many ways to manage its symptoms. Consult with an eye doctor to determine the best treatment for your situation.
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