What is Macular Degeneration?
Macular Degeneration is a disease that – over time – destroys the part of the eye that uses Central Vision. Designed to view objects more clearly, Central Vision is essential to daily tasks such as reading and driving. Breakthroughs in macular degeneration inspire hope that someday there will be a cure for the disease.
What causes Macular Degeneration
Macular Degeneration occurs as the macula section of the retina starts to deteriorate. The retina controls the sensitivity of light that enters the eye. When the retina is damaged, the eye’s nerve control system to the brain is impaired, which causes blurred vision.
- No pain is linked with macular degeneration. Loss of vision occurs gradually and affects both eyes at different rates. Sometimes, only one eye loses vision while the other continues to see well for years. Other times, peripheral vision may remain clear, even with a loss of central vision.
- The condition is barely evident in early stages. A very frequent, and important, symptom to be aware of is distortion (i.e. where straight lines will not look straight). The Amsler grid (shown to the left) will appear distorted and the small boxes in the area will vary in shape and size. You may also notice the size of objects appear different from each eye or that colors do not look the same from each eye.
Types of Age-Related Macular Degeneration (AMD)
Most common symptoms:
- Slightly blurred vision.
- Difficulty in recognition of faces and places.
- Blurred spot in center of vision.
Unfortunately, at this time, there is no single proven treatment for the dry form of macular degeneration. Although there is not a cure for this disease, SWOA provides various medical treatments.
One form of treatment for early dry ADM is nutritional therapy, with a healthy diet high in antioxidants to support the cells of the macula.
The following is the nutrient supplementation (recommended in addition to a healthy, balanced diet) shown to be beneficial in lowering the risk of macular degeneration progressing to advanced stages:
- Vitamin C – 500 mg
- Vitamin E – 400 IU
- Lutein – 10 mg
- Zeaxanthin – 2 mg
- Zinc oxide – 80 mg
- Copper (as cupric oxide) – 2 mg (to prevent copper deficiency, which may be associated with taking high amounts of zinc)
It is important to remember that vitamin supplements are not a cure for macular degeneration, nor will they give you back vision that you may have already lost from the condition.
If AMD is advanced, but still dry, supplements are prescribed, to add higher quantities of certain vitamins and minerals which may increase healthy pigments and support cell structure.
In the advanced stages of Macular Degeneration, straight lines appear wavy. Also, loss of vision occurs quickly.
Treatment for Wet AMD: Anti-VEGF Therapy
VEGF is an acronym for vascular endothelial growth factor. Currently, the most common and effective clinical treatment for wet Age-related Macular Degeneration is anti-VEGF therapy – which is periodic intravitreal (into the eye) injection of a chemical called an “anti-VEGF.” In the normal life of the human body, VEGF is a healthy molecule which supports the growth of new blood vessels. In the case of macular health, though, VEGF is unhealthy. It promotes the growth of new, weak blood vessels in the choroid layer behind the retina, and those vessels leak blood, lipids, and serum into the retinal layers. The leakage (hemorrhaging) causes scarring in the retina and kills macular cells, including photoreceptor rods and cones.
An intraocular shot of an anti-VEGF drug inhibits the formation of new blood vessels behind the retina and may keep the retina free of leakage. An injection in the eye can be a disconcerting experience, and it may take several treatments to become accustomed to the procedure. However, the shot is usually not painful because the eye has been anesthetized. The procedure takes about fifteen minutes. Usually the appointment requires an hour. The effect lasts for a month or maybe more.
Researchers report high rates of success with anti-VEGF injections, including receding blood vessels behind the retina, a far slower progression of the disease, and, in some cases, moderate gains made in vision. In some parts of the world, anti-VEGF treatments have reduced the incidence of legal blindness by 50 percent. However, they have noted that injections of even small amounts of anti-VEGF drugs could — though research is inconclusive — have an effect on vascular function in the rest of the body. Strokes and hemorrhaging are two concerns, but because cardiovascular disease is already often associated with Age-related Macular Degeneration, any data available to date about strokes or hemorrhaging has been difficult to interpret.
Laser treatment for wet macular degeneration
Although most cases of wet AMD are treated with medication, in some instances, thermal laser therapy may be used. Laser treatment is usually done at an outpatient procedure and can be completed at our onsite surgical center, OSI.
The laser beam in this procedure is a high-energy, focused beam of light that produces a small burn when it hits the area of the retina to be treated. This destroys the abnormal blood vessels, preventing further leakage, bleeding and growth.
Following laser treatments, vision may be more blurry than before treatment, but often it will stabilize in a few weeks. A scar forms where the treatment occurred, creating a permanent blind spot that might be noticeable in you field of vision.
Usually the abnormal blood vessels are destroyed by laser treatment. However, it is likely that 50 percent of patients with wet macular degeneration who receive this laser procedure will need a re-treatment within three to five years.
Photodynamic therapy (PDT)
In some cases, a type of treatment for wet macular degeneration, called photodynamic therapy (PDT), may be an option. This therapy uses a combination of a light-activated drug called a photosensitizer and a special low-power, or cool, laser to treat wet macular degeneration right at the center of the macula.
Types of Anti-VEGF Drugs
Several anti-VEGF drugs are being developed to inhibit VEGF by trapping it or preventing it from binding with elements which will stimulate growth. Chemically synthesized short strands of RNA (nucleic acid) called “aptamers” prevent the binding of VEGF to its receptor. The various forms of anti-VEGF injections include ranibizumab (Lucentis, made by Genentech/Novartis), bevacizumab (off label Avastin from Genentech), and the recently Food and Drug Administration-approved aflibercept (Eylea/VEGF Trap-Eye from Regeneron/Bayer). Each of these chemicals works in a different way to inhibit blood vessel growth.