How is age-related macular degeneration diagnosed?
Your ophthalmologist will perform a complete examination to diagnose AMD. One of the most common early signs of AMD is the presence of drusen. Your doctor can see these during a routine eye exam. Often, an optical coherence tomography (OCT) picture will be taken. OCT shows how thick the retina is and can identify accumulated fluid from abnormal blood vessels. A new kind of OCT, “OCT angiography” can show some things a fluorescein angiogram (see below) can show but without the dye injection.
The doctor may order a fluorescein or indocyanine green angiogram to look for the abnormal blood vessels within or under the retina. During each of these procedures, dye is injected in the arm, and photographs (not X-rays) are taken from a special camera to track the movement of the dye as it reaches the eye, and to show any changes in the retina. If new vessels are leaking fluid or blood in the macula, the photographs show their location and type.
People with macular degeneration can check their own vision with a simple test called the Amsler grid. The Amsler grid is a pattern of straight lines that make perfect squares. The patient looks at a large dot in the middle of the grid and notices any areas where the lines look blurry, wavy or broken. If the grid lines seem to be more distorted than before, it might be a sign that the macular degeneration is getting worse and needs evaluation.
Early detection of AMD is very important because treatment can delay or reduce the severity of the disease.