Diagnostic Tests
In Canada, a number of tests can be performed to detect and diagnose AMD (and other conditions that can impair vision), even before symptoms might be apparent. In addition to the standard visual acuity (eye chart) tests to assess the eye's ability to distinguish details and shape at varying distances and lighting situations, the following tests may be specifically performed to diagnose AMD:
Dilated eye exam: Eye care professionals can use a variety of techniques and instruments to examine the retina and the optic nerve for disease characteristics of AMD. Eye drops are placed in the eye to widen or dilate the pupils.
Ophthalmoscopy: By shining a small light onto the back of the eye, eye care professionals are looking for the presence of drusen, the most common early sign of AMD. The presence of drusen alone does not indicate a disease, but it might mean that the person is at risk for developing AMD. Learn more about how drusen affects the eye by taking the AMD Challenge.
Fluorescein angiograthy: This procedure involves injecting a non-toxic dye into the bloodstream through the arm to capture blood vessel growth, leakage and deposits in the retina and macula. Pictures are taken as the dye passes through the blood vessels in the retina to identify any leaking blood vessels and diagnose wet AMD. Other imaging studies may also give valuable information on the type and extent of the disease.
Amsler grid: This test, using a grid that resembles graph paper with a dot in the center, can be performed at home, but it may also be given by an eye care professional. By looking directly at a spot in the center of a grid, one eye at a time, people can determine whether they have symptoms of AMD if the lines on the grid appear blurred or wavy, or if the center spot is not visible. Learn more about the Amsler grid.
