What is Macular Degeneration?
Age-related macular degeneration (AMD) is the leading cause of vision loss in the U.S., with more than 13 million Americans showing some sign of the disorder. AMD is usually a slow, but variably progressive disease that causes a reduction in central vision – the vision you need for close work like reading a newspaper. It is most common in people over the age of 65. Age-Related Macular Degeneration occurs in two forms. The most common form of AMD is Dry AMD. Drusen, tiny yellow deposits, develop beneath the macula and signal degeneration and thinning of nerve tissue. Wet AMD is less common but requires immediate medical attention to preserve central vision. About 10% of cases of dry macular degeneration develop into the wet form of AMD. Abnormal blood vessels grow beneath the macula leaking blood and fluid onto and underneath the retina.
What Causes Macular Degeneration?
The macula is a very small portion of the retina that is responsible for your central vision. About the size of a pencil eraser, the macula is loaded with photoreceptors that enable you to see anything that requires focused vision whether it is reading, sewing, computer work, watch television, or anything else. Tissue damage caused by AMD distorts part of the central image that your eye transmits to your brain.
Most people with AMD do not experience total loss of vision. It is the central vision used for up-close tasks that is lost. Regular eye exams can detect early signs of AMD. More extensive testing such as angiography can also be utilized to aid in detection. Newer technology and research has helped physicians halt or slow progression of retinal changes in AMD patients.
AMD Treatment - Macugen
Recently, the Food and Drug Administration approved a new drug called Macugen for the treatment of wet age-related macular degeneration. The wet form of AMD causes sudden severe vision loss due to the invasion of the macula by leaking, fragile blood vessels. The exact reason why these blood vessels grow is unclear, but is believed to be related to a protein secreted in the retina. Macugen works by blocking this protein, thereby preventing the blood vessel growth.
Macugen is injected into the cavity of the eye (vitreous) by an ophthalmologist and is slowly absorbed into the bloodstream. The injection is given every six weeks for one year. After the first year, your ophthalmologist will discuss the benefit of continuing the injections into the second year. You should not receive Macugen if you have an eye or eyelid infection. Tell your doctor if you are experiencing any eye discharge, itching, burning or redness.
Photo-Dynamic Therapy is another treatment used to help manage the “wet” form of macular degeneration. Treatment is accomplished with the use of an intravenous injection of a light sensitive medication called Visudyne®. Once injected, applying a low-powered laser beam to specific areas of the macula where the lesion is located activates the medication. The activated Visudyne® then begins to destroy the abnormal vessels to prevent them from further leaking. Usually, multiple treatments are needed. Unlike traditional laser photocoagulation, PDT does not cause surrounding tissue damage. PDT usually does not restore vision already lost. The expectation is to halt further vision loss from the disease. Preservation of the existing sight in the affected eye is the goal of treatment. PDT does not benefit all patients with wet macular degeneration, and certain criteria need to be met before treatment can be administered.
Nutritional Guidelines for Patients with AMD
In 2001, the National Eye Institute released its finding of a large clinical trial of high doses of Vitamin C, E, and Beta Carotene, along with Zinc used for patients with AMD. This study statistically demonstrated the benefits of these supplements for patients with moderate to severe AMD. The study did not statistically prove that patients with only minimal changes from macular degeneration benefit from these supplements. The use of nutritional supplements for AMD is a decision made by the eye doctor, patient and primary physician. In view of previous studies, Beta Carotene should not be used by recent ex-smokers or smokers due to the potential increased risk of lung cancer.
These supplements are commercially available and approximate the nutrients’ studies. Unfortunately, diet and multiple vitamins do not approach adequate levels of these nutrients. Always check with your doctor before starting any new supplements.
To Reduce Your Risk of Developing Age-Related Macular Degeneration:
- Wear glasses or sunglasses with UV 100 protection.
- Keep your blood pressure under control.
- Stop smoking. Smoking increases the risk of developing AMD – 9 times more likely to occur than with non-smokers.
- East plenty of green, leafy vegetables.