ISCEV standard for clinical visual evoked potentials (2009 update)

Abstract: Visual evoked potentials (VEPs) can provide important diagnostic information regarding the functional integrity of the visual system. This document updates the ISCEV standard for clinical VEP testing and supersedes the 2004 standard. The major change in this revision is that test parameters have been made more precise to achieve better consistency of results within and between test centers. The ISCEV standard VEP protocols are defined for a single recording channel with a midline occipital active electrode. These protocols are intended for assessment of prechiasmal function; additional electrode sites are recommended for evaluation of chiasmal and postchiasmal function. ISCEV has selected a subset of stimulus and recording conditions that provide core clinical information and can be performed by most clinical electrophysiology laboratories throughout the world. These are: 1. Pattern-reversal VEPs elicited by checkerboard stimuli with large 1A degrees (i.e., 60 min of arc; min) and small 0.25A degrees (15 min) checks. 2. Pattern onset/offset VEPs elicited by checkerboard stimuli with large 1A degrees (60 min) and small 0.25A degrees (15 min) checks. 3. Flash VEP elicited by a brief luminance increment, a flash, which subtends a visual field of at least 20A degrees.