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What is Electroretinography (ERG)?


An electroretinography test, also known as an electroretinogram, measures the electrical response of light sensitive cells in your eyes. The light sensitive cells are referred to as rods and cones, which are located in the back of your eye known as the retina. There are 120 million rods in the human eye and 6 to 7 million cones. The cones are responsible for eye color sensitivity and the rods are more sensitive to light sensitivity. Your doctor may perform an electroretinogram test to determine if you have inherited or acquired a disorder in the retina. Some of these disorders can include retinitis pigmentosa, macular degeneration, retinoblastoma, retinal separation, cone-rod dystrophy, or to assess if you need retina surgery or removal of cataracts.

What Happens During an Electroretinography Test?

To begin, your doctor at Marano Eye Care will administer anesthetic eye drops to dilate and numb your eyes while you sit or lie in a comfortable position. Then your physician will place a device known as a retractor, which is used to hold your eyelids open for the duration of the test. A small electrode that is about the size of a contact lens is placed over each eye to measure the electrical response from your retina. You will then be asked to watch a flashing light in a normal lit room and in a darkened lit room as well. The normal lit room is mainly to observe the retina’s cones, and the darkened lit room is to examine your retina’s rods. This procedure should take about an hour to perform depending on your doctor

What are the Risks with an Electroretinography Test?

There are zero risks linked to an electroretinography test. During the exam, some patients may feel a slight discomfort, which is completely normal. Patients have described the placement of the electrode as similar to having an eyelash stuck in their eye. In extremely rare cases some patients may suffer from a corneal abrasion from the test. If this happens your physician can detect it early and treat it easily. 

What Happens After an Electroretinography Test?

Your eyes may feel sore and sensitive after the procedure is performed. Try not to rub your eyes for up to an hour after the test. Rubbing your eyes can cause corneal damage because your eyes will still be numb from the anesthetic eye drops. Depending on your results, the physician may want to run more tests to further assess your eyes, prescribe medication, or suggest surgery if a disorder is detected in your eye.

Electroretinography Testing in New Jersey

At Marano Eye Care, we are committed to providing our patients elite eye care. We are here to support our patients eye health and enhance their vision. Learn more about how Marano Eye Care can help you prevent future eye complications and receive useful guidelines on how to take care of your eyes. Contact or schedule an appointment with us at our convenient Denville, Livingston, or Newark locations today.

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