Macular Degeneration

Diagnosis

The diagnosis of macular degeneration is made based on a thorough eye exam. Following diagnosis, additional tests may be performed to determine the location and extent of the disease.

Eye Exam

The doctor looks for presence of abnormalities in the macula, such as deposits called drusen. In addition, the appearance of the macula is important to sharp central vision — if the pigmentation is mottled or uneven, instead of its normal even reddish color, macular degeneration is usually the cause.

Amsler grid test

As a part of the eye examination, the physician may evaluate the patient's vision using a printed grid. If macular degeneration is present, the lines of the grid may seem faded, broken or distorted. By noting where the distortion occurs (usually near the center of the grid), the doctor can better determine the location and extent of macular damage.

Fluorescein angiography

After diagnosis, the physician may perform this test to determine the extent of the damage from macular degeneration. First, the doctor injects dye into a vein in the patient's arm. As the dye circulates through the bloodstream and eventually to the eye, the blood vessels in the retina stand out as bright yellow when observed with a special blue light. A camera takes flash photographs of the eye every few seconds for several minutes, which help the doctor determine pigmentation changes or abnormal blood vessels.

Indocyanine green angiography (ICGA)

Another type of angiography of the vessels in the eye is ICG. ICG is a dye that lights up when exposed to infrared light. Infrared light is used to take pictures of the back of the eye visualizing retinal blood vessels, and the deeper, harder to see choroidal blood vessels.