Macular Degeneration

Age-Related Macular Degeneration (ARMD) is the leading cause of vision loss in people over 50 in the United States. ARMD occurs when the macula, which is located in the center of the retina and provides us with sight in the center of our field of vision, begins to degenerate. With less of the macula working, central vision - which is necessary for driving, reading, recognizing faces, and performing close-up work - begins to deteriorate.

Types of ARMD

• Dry ARMD - Is responsible for 90 percent of disease cases. While its cause is unknown, it occurs as the light sensitive cells in the macula slowly deteriorate, generally occurring in one eye at a time.
• Wet ARMD - Is responsible for 10 percent of disease cases, but accounts for 90 percent of all severe vision loss caused by either type of ARMD. This occurs when new blood vessels behind the retina start to grow beneath the retina where they leak fluid and blood and can create a large blind spot in the center of the visual field. If this happens, there is a marked disturbance of vision in a short period of time.

Symptoms of ARMD

• blurry or fuzzy vision
• difficulty recognizing familiar faces
• straight lines, such as sentences on a page, telephone poles, and the sides of buildings, appear wavy a dark or empty area (blind spot) appears in the center of vision
• rapid loss of central vision - vision necessary for driving, reading, recognizing faces, and performing close-up work

Diagnosing ARMD

• Visual acuity test - the common eye chart test, which measures vision ability at various distances.
• Pupil dilation - the pupil is widened with eye drops to allow a close-up examination of the eye's retina.
• Amsler grid - used to detect wet ARMD, this diagnostic test uses a checkerboard-like grid to determine if the straight lines in the pattern appear wavy or missing to the patient - both indications may signal the possibility of ARMD.
• Fluorescein angiography - used to detect wet ARMD, this diagnostic test involves a special dye injected into a vein in the arm. Pictures are then taken as the dye passes through the blood vessels in the retina, helping the physician evaluate if the blood vessels are leaking and whether or not the leaking can be treated.
• Ocular coherence tomography - a test to measure the thickness of the retina.

Risk Factors for ARMD

• gender - Women are at greater risk than men.
• age - The risk for developing the disease increases as a person ages. Studies have shown that while persons in their 50s have only a two percent risk of developing ARMD, that rises to nearly 30 percent in persons over 75.
• smoking - Smoking is a major risk factor for age-related macular degeneration.
• family history - Persons with a family history of ARMD may have a higher risk of developing ARMD.
• high blood cholesterol levels - Persons with elevated blood cholesterol levels may be at higher risk for wet ARMD.

Treatment for ARMD

• your age, overall health, and medical history
• extent of the disease
• your tolerance for specific medications, procedures, or therapies
• expectations for the course of the disease
• your opinion or preference

Treatment for wet ARMD may include laser surgery in which a high energy beam of light is aimed directly onto the leaking blood vessels to deter further leaking; photodynamic therapy which uses a drug and laser in combination; and new drugs called angiogenesis inhibitors are also used.

Currently, there is no treatment for dry ARMD. This does not, however, indicate that sight will automatically be lost, particularly if the ARMD affects only one eye. Central vision may eventually be lost or diminished, but generally the rate of loss is slow.