Macular Degeneration

Age related macular degeneration (AMD) is one of the most common causes of poor vision in patients after the age of 60. Although the specific cause is unknown, AMD seems to be a part of aging.

AMD accounts for 90 percent of new legal blindness in the US. Visual symptoms of AMD involve loss of central vision, but the peripheral vision is unaffected. Patients can lose the sharp, central vision necessary for driving, reading and recognizing faces when parts of the image are missing.

Risk Factors

Types

Diagnosis

Possible Risk Factors Include:

Gender – according to some studies, women are at greater risk than men.
smoking – recent studies have shown that smoking is a major risk factor for age-related macular degeneration.
Family history – persons with a family history of AMD may have a higher risk of developing AMD.
Obesity – studies have indicated that obesity may be linked to the progression of AMD.
High blood cholesterol levels – persons with elevated blood cholesterol levels may be at higher risk for wet AMD.
Hypertension and cardiovascular disease

Chart Illustrating a Healthy Eye Vs One With a Degenerated Macula

Chart Illustrating a Normal Eye Compared to a Wet and Dry Macular Degeneration

There Are Two Primary Types of AMD:

Dry AMD

This type of AMD is the most common. 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 AMD

This type of AMD is less common, but accounts for almost all severe vision loss caused by either type of AMD. Wet AMD 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.

How is AMD Diagnosed?

AMD is Detected During a Comprehensive Eye Exam That Includes:

Visual Acuity Testing

The eye chart test measures how well you see at various distances.

Dilated Eye Exam

Drops are placed in your eyes to widen, or dilate, the pupils. A special magnifying lens to examine your retina and optic nerve for signs of AMD and other eye problems. After the exam, your close-up vision may remain blurred for several hours.

Amsler Grid

The pattern of the grid resembles a checkerboard. You will cover one eye and stare at a black dot in the center of the grid. While staring at the dot, you may notice that the straight lines in the pattern appear wavy. You may notice that some of the lines are missing. These may be signs of AMD.