In the United States, the leading causes of blindness and vision loss are age-related eye diseases such as macular degeneration, cataract, diabetic retinopathy and glaucoma.
Today, as part one of our four-part eye disease series, we’re focusing on an in-depth discussion of the symptoms, characteristics and treatment of age-related macular degeneration (AMD).
AMD is a very common eye condition, and the leading cause of vision loss in people age 50 and older.
AMD causes damage to the macula, a small spot close to the center of the retina. It’s the part of the eye that’s needed for central vision, which enables a person to see objects that are straight ahead.
For most people, AMD progresses at a slow rate; however, for others, this disease advances more quickly and can potentially lead to a loss of vision in one or both eyes. As AMD progresses, a common symptom is a blurred area near the center of vision which, over time may grow bigger. The person may also develop blank spots in his or her central vision.
Usually, the early and intermediate stages of AMD are without symptoms, and only a comprehensive dilated eye exam can detect this disease.
There are two forms of AMD: wet and dry.
Wet AMD – This occurs when abnormal blood vessels located behind the retina start to grow under the macula, ultimately leading to blood and fluid leakage. This, in time, can cause damage and lead to rapid central vision loss. A symptom of wet AMD is when straight lines appear to be wavy.
Dry AMD – Over time, the macula thins and gradually will blur central vision. This form of AMD is more common than wet, accounting for 70–90 percent of AMD cases, and often affects both eyes. The progression is slow, but eventually less of the macula functions and central vision is lost in the affected eye. A common symptom of dry AMD is drusen: tiny, yellow or white deposits located under the retina.
There is no cure for AMD; however, there are treatment options that may prevent severe vision loss or even slow the progression of this disease. These forms of treatment include:
Anti-angiogenic drugs – This type of medication is injected into the eye to block the development of new blood vessels and leakage from the abnormal vessels in the eye that cause wet AMD. Anti-angiogenic drugs have proved to be an effective treatment, and many patients have actually regained lost vision.
Laser therapy – In this form of treatment, high-energy lasers can be used to destroy the actively growing abnormal blood vessels that appear in AMD.
Photodynamic laser therapy – This type of therapy is a three-step treatment. First, a light-sensitive drug is used to damage the abnormal blood vessels. Then, a medication is injected into the bloodstream to be absorbed by the abnormal blood vessels. Finally, the doctor shines a cold laser straight into the eye in order to activate the drug.
As always, consult your doctor to learn more about potential eye diseases, including AMD. And check back next week when we discuss the signs, symptoms and treatment options for cataracts.