Official diagnosis of AMD must be made by an ophthalmologist or optometrist. Early detection of AMD is important as treatments such as laser photocoagulation and Visudyne™ (a photodynamic therapy) may halt or slow progression of the disease only if detected at an early state. Unfortunately, it will usually not reverse existing retinal damage. Therefore, regular eye exams are crucial to detecting AMD in its early stages.

According to the American Academy of Ophthalmology (AAO), "asymptomatic individuals 40 to 64 years of age who have had a previously comprehensive examination, the recommended interval for interim evaluations is two to four years. For the age group of 65 or older, the AAO recommends an examination every one to two years, even in the absence of symptoms." (AAO Policy Statement, September 15, 1990)

Methods of Detection

Decreased central visual acuity - the ability to see at various distances - is the classic symptom of age-related macular degeneration. The decreased visual acuity or image distortion is often termed metamorphopsia. Metamorphopsia can easily be detected with an Amsler Grid.

Since many patients with dry macular degeneration have no symptoms, an ophthalmoscopic examination is conducted. Ophthalmoscopic examination allows for detection of both early and late signs of macular degeneration.

Angiographic Diagnosis - The fluorescein angiogram is fundamental in diagnosis and treatment of choroidal neovascularization or the abnormal growth of blood vessels on or under the retina. It allows the retinal specialist to pinpoint the location and extent of neovascularization. It can also assist in guiding laser photocoagulation if indicated. However, only about 13% of angiograms show a treatable localized lesion (drusen) or classic choroidal neovascularization. The other 87% show diffused, poorly defined lesions that are not appropriate for laser photocoagulation or Visudyne therapy. These lesions are called occult choroidal neovascularization.

In this test, a special dye is injected intravenously and pictures are taken as the dye passes through the vessels in the retina. These photos identify leaking blood vessels or choroidal neovascularization. Improvements in this testing procedure have recently proven to be more effective at identifying poorly defined or occult choroidal neovascularization with a newer dye, indocyanine green (ICG) that permits better visualization.

Amsler Grid

The Amsler Grid is a chart that may be helpful in revealing signs of wet age-related macular degeneration (AMD); however, it is not a substitute for regularly scheduled eye exams/tests. The grid looks like a piece of paper with dark lines that form a square grid with one dot in the middle. To administer the test, hold the Amsler Grid at eye level at a comfortable reading distance. If you wear any type of reading lenses, wear them during the test. Cover one eye at a time, and focus on the center dot. If you notice any of the potential signs of AMD like wavy, broken or distorted lines or blurred or missing areas of vision, you should contact your eye care provider immediately. Remember that the Amsler Grid is not a substitute for regularly scheduled eye exams/tests, which should take place at least once every two years, especially after the age of 40.

To test yourself:

Print a copy of the Amsler Grid, and hang grid with the center dot at eye level on a bare wall in a well-lighted room. Wearing the glasses or contacts you normally wear for reading, stand 13 inches/33 cm from the wall. Cover one eye with your hand, then focus on the center dot with uncovered eye. You should see all four corners of the grid. Repeat with other eye. If you see wavy or fuzzy lines, you may be displaying symptoms of AMD. Click on the grid below for a printable version.

Please note that some people with AMD may not see distortions on the Amsler grid. Any noticeable change in your vision should be reported to your eye doctor immediately.

Macular Degeneration