Objective perimetry in glaucoma: Recent advances with multifocal stimuli

The introduction of multifocal stimulus recording has enhanced our ability to examine the human visual field with electrophysiologic techniques. We ha ve adapted the multifocal pattern visual evoked potential (PVEP) to detect visual field loss. In glaucoma patients we sought to determine the extent t o which the PVEP amplitudes correlate with perimetric thresholds. Multifoca l pseudorandomly alternated pattern stimuli, which were cortically scaled i n size, were presented with use of the VERIS-Scientific system. Bipolar occ ipital straddle electrode positions were used. The visual field up to 25 de grees of eccentricity was investigated. Forty-three glaucoma patients with reproducible visual field defects were tested. The bipolar PVEP corresponde d well with Humphrey visual field defects, showing loss of signal in the sc otoma area. For Humphrey quadrant threshold totals and PVEP quadrant amplit udes, the correlation coefficient was strong (r = 0.49, P < 0.0001). The mu ltifocal PVEP demonstrates good correspondence with the topography of the v isual field. This technique represents the first practical application of t he multifocal PVEP to objective detection of visual field defects in glauco ma. (C) 1999 by Elsevier Science Inc. All rights reserved.