|
|
|
ERG (Electroretinogram) This is an eye test that evaluates the function of the film (retina) that lines the inside of the eye. The processes that start vision take place in the retina. The retina is the most metabolically active tissue in the body. The ERG test helps diagnose diseases limited to the retina, and also diseases that affect parts of the body other than the eye. The idea of the ERG test is that when flashes of light come to the eye, the rods and the cones and other cells in the retina make tiny amounts of electricity. If we know exactly how much light come to the eye, and how much electricity comes out, we can figure out how the cells, including the rods and cones, are working. To pick up the electricity that the retina makes, contact-lens like electrodes, are placed on the surface of the eye. To prepare for the ERG test, first of all drops will be placed in your child's eye to dilate the pupils (enlarge the black spot in the middle of the eye). These drops are the same drops that eye doctors routinely use for examination of the eyes. Then we will ask that you sit with your child in the dark room for 30 minutes. This is so that the eye can adjust to the darkness. It is after this period of dark adaptation that the retina gives its strongest responses. During the 30 minutes in the dark, there is a radio available. Also you may bring favorite audio tapes and player. Some children may enjoy a small snack. After the period of dark adaptation, the actual testing is done in a dark room and takes about 30 to 45 minutes to record a full range of responses. If the range of responses is reduced, the duration of the testing will be shorter. The ERG testing does not hurt, beyond the momentary stinging of the drops that are used to dilate the pupils and the anesthetic drops used just before the contact lenses are placed. The hard part of the test is holding still. We ask parents to stay with their child all through the period of dark adaptation and the test. For infants and young children a bottle, or a pacifier, can be helpful. We will also ask the parent to hold the child's hands gently so that the contact lenses cannot be touched. As with any contact lens, it is possible to scrape the surface of the eye. This has not been a problem with the procedures that we use. However, the precautions that we exercise are important to minimize the chance of any scraping of the eye's surface. At the end of the test, we will check the surfaces of the eyes with some yellow drops, (fluorescein) to look for any signs of scraping by the contact lenses. During the test some information about the results becomes available. We will convey this to you. However, as you will see, many records are obtained and these all have to be measured and analyzed for the final report. We will send a copy of the ERG report to you and also to any physicians designated by you. We are happy to discuss the reports with you and your child's other physicians. When you are here for the ERG, we will show you the equipment and answer questions that you may have about the nature and purpose of the ERG procedure. Please contact us (617-355-6413) if you have questions prior to the visit. Anne B. Fulton, M.D. Click here to watch the ERG video
|