Distribution and Rates of Visual Field Loss across Different Disease Stages in Primary Open-Angle Glaucoma

Abstract

To identify patterns and rates of visual field (VF) loss in primary open-angle glaucoma (POAG) across different levels of severity. Retrospective, observational case series. Visual fields of 278 eyes of 139 patients with POAG (9 years of follow-up with ∼17 visits) from the Rotterdam Eye Hospital in The Netherlands were analyzed to identify patterns and rates of VF loss. Rate of VF decline for the entire VF, each region, and test point. Hemifield asymmetric rate if VF decline for each region and test point. Total deviation (TD) values were extracted from the Humphrey VF Analyzer (Carl Zeiss Meditec, Dublin, CA). Eyes were stratified into 3 glaucoma stages by means of the mean deviation (MD): better than-6 decibels (dB), worse than-6 dB and better than-12 dB, and worse than-12 dB. Each hemifield was divided into 5 regions according to the Glaucoma Hemifield Test (GHT): central, paracentral, nasal, and peripheral arcuates 1 and 2. Point-wise and region-wise asymmetric patterns of VF loss and rate of VF loss were identified by comparing the values in the superior hemifield and the inferior hemifield at each severity level using a generalized estimating equation. The mean age of the patients was 60.2±10.3 years (mean ± standard deviation [SD]). The rate of MD loss, for all eyes taken together, was-0.11 dB/year. In the cross-sectional analysis, in eyes in the early and moderate stages, central and peripheral arcuate 2 regions in the superior hemifield were worse than their inferior counterpart, whereas in the advanced stage all GHT regions in the superior hemifield were significantly worse than the corresponding regions in the inferior hemifield (P ≤ 0.05). In the longitudinal analysis, there was no significant difference in the rate of VF loss between the GHT regions in the superior and inferior hemifields. Our findings suggest that in POAG, VF damage is worse in the superior hemifield than in the inferior hemifield.