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Electroretinogram (ERG)

An electroretinogram (ERG) is a diagnostic procedure that evaluates the function of the retina, the light-sensitive lining on the back of the eye where light is focused. This test can aid in the diagnosis of several different retina conditions that can lead to serious complications, including permanent vision loss.

During the ERG procedure, the cells of the retina release electric responses to the flashes of light. By measuring these electrical responses to the light under varying conditions, your doctor can determine how well the retina is working. This is done by placing a contact lens on the eye to record responses to a series of lights. A multifocal ERG is a special type of ERG that measures responses from multiple retinal areas using an array of light signals. The results of this exam are then analyzed through a special map of the eye.

The entire ERG procedure typically takes 30-45 minutes to perform and is available to our patients at Wills Eye Hospital. This procedure is performed with dilated pupils in order to achieve the most accurate results.