Tests and diagnosis

By Mayo Clinic Staff

Doctors will review your medical history and family history, and conduct a comprehensive eye exam to diagnose your condition. Doctors may conduct several tests to diagnose dry macular degeneration, including:

  • Examination of the back of your eye. Your eye doctor will examine the back of your eye to look for a mottled appearance that's caused by drusen — yellow deposits that form under the retina in people with macular degeneration. Your eye doctor will put drops in your eyes to dilate your eyes and use a special instrument to examine the back of your eye.
  • Test for defects in the center of your vision. During an eye examination, your eye doctor may use an Amsler grid to test for defects in the center of your vision. You may have macular degeneration if some of the straight lines in the grid look faded, broken or distorted.
  • Fluorescein angiogram. During an angiogram of your eye, your doctor injects a colored dye into a vein in your arm. The dye travels to and highlights the blood vessels in your eye.

    A special camera takes several pictures of the blood vessels in your eye as the dye travels through the blood vessels. The images will show if you have abnormal blood vessel or retinal abnormalities in your eye, such as those associated with wet macular degeneration.

  • Optical coherence tomography (OCT). This noninvasive imaging test displays detailed cross-sectional images of the retina. The test identifies areas of retina thinning, thickening or swelling. These are caused by fluid accumulations from leaking blood vessels in and under your retina. In addition to its value in an initial evaluation, OCT is also often used to help monitor the response of the retina to macular degeneration treatments.

Determining the stage of your dry macular degeneration

Dry macular degeneration is categorized in three stages based on the progression of damage in your eye:

  • Early stage. In early macular degeneration, doctors may detect several small drusen or a few medium-sized drusen under the retina in one or both eyes. Generally, you won't experience any vision loss in the earliest stage.
  • Intermediate stage. In intermediate macular degeneration, doctors detect a large number of medium-sized drusen or one or more large drusen in one or both eyes. At this stage, you may not have symptoms. However, you may notice your central vision is blurred, or you may need extra light for reading or doing detail work or it may take you longer to recover your vision when entering a room that is not well illuminated.
  • Advanced stage. In advanced macular degeneration, doctors detect several large drusen, as well as extensive breakdown of cells in the macula. You may have a well-defined area of blurring in your central vision, which may gradually grow larger.
Sept. 19, 2015