Abstract
Purpose: :
The Advanced Glaucoma Intervention Study (AGIS) scoring system is a quantitative method of assessing the severity of glaucomatous visual field (VF) loss. The aim of this study was to investigate the correlations between electroretinogram photopic negative response (PhNR) and pattern electroretinogram (PERG) amplitudes, and AGIS scores in primary open angle glaucoma (POAG).
Methods: :
Twenty-six eyes of 26 patients with POAG and glaucomatous VF defects were enrolled. Photopic ERGs were elicited by red stimuli (4 ms duration; 644 nm, 3 cd.s/m2, 1.4 Hz) on a blue background (470 nm, 17 cd/m2). PERGs were recorded in accordance with the ISCEV standard (90% contrast; check size: 0.8°, reversal rate: 1.7 Hz). For comparison purposes, VF printouts of the 24-2 threshold program single-field test STATPAC-2 (Humphrey Visual Field Analyzer) were analyzed using the AGIS score.
Results: :
Mean PhNR and PERG P50 amplitudes were 17.2±10.2 µV and 1.9±1.8 µV, respectively. AGIS scores median assessed was 5 (range: 0-20). Spearman tests showed moderate but statistically significant correlation between PERG and AGIS score (r= -0.516, P=0.007) and between PhNR and AGIS score (r= -0.402, P=0.042). There was no significant correlation between PhNR and PERG P50 amplitudes.
Conclusions: :
The relationship found between PhNR, PERG and AGIS scores in POAG suggests that these measurements reveal impairment of ganglion cell function. Although they may assess different aspects of the pathological process, they might be considered as useful complements in monitoring cases of moderate and advanced POAG.
Keywords: electroretinography: clinical • visual fields