TY - CHAP M1 - Book, Section TI - Chapter 581. Special Tests of the Eyes A1 - Karr, Daniel J. A1 - Levin, Alex V. A2 - Rudolph, Colin D. A2 - Rudolph, Abraham M. A2 - Lister, George E. A2 - First, Lewis R. A2 - Gershon, Anne A. PY - 2011 T2 - Rudolph's Pediatrics, 22e AB - The electroretinogram (also known as full-field ERG) is a measure of retinal photoreceptor integrity and thus retina function. The basic technique consists of measuring the action potential produced by the retina when stimulated by light of variable intensity and color. ERG allows differentiation between the responses of the retinal rod and cone systems. A contact lens with an imbedded electrode is placed on the cornea, or a skin electrode is placed on the lower lid. A reference skin electrode is placed on the forehead. The ERG can be performed awake in infancy and later childhood but usually requires sedation or general anesthesia between the ages of 1 and 6 years. The first step of the ERG is dark adaptation, which is done by double patching both eyes for at least 20 minutes. Then, in a completely dark environment, the test is started. Sleeping or awake, quiet infants and children under sedation or anesthesia lie supine while the bowl-shaped machine is brought over their face. Older children can sit upright and their chin is placed on a rest within the bowl. As variable light stimuli are presented within the bowl, the electrical potential between electrodes is then measured and recorded as a waveform. In anxious children dim light adaptation (mesoptic vision) can be substituted. SN - PB - The McGraw-Hill Companies CY - New York, NY Y2 - 2024/10/11 UR - accesspediatrics.mhmedical.com/content.aspx?aid=7059677 ER -