Glaucoma Progression Detection: Comparison of Expert Visual Field Evaluation and Glaucoma Progression Analyzer

Abstract

Purpose: : to compare the capability of the Glaucoma Progression Analyzer (GPA) algorithm of the Humphrey Field Analyzer against expert visual field evaluation in the detection of glaucoma progression.

Methods: : fifty four eyes with diagnosis of open angle glaucoma were recruited from 2000 until 2004 in a prospective study. All patients were examined with Humphrey Visual Field Analyzer static perimetry (24-2 SITA Standard) six monthly being followed for no less than 36 months. The two tests chosen as GPA baseline required a maximum time difference of four months, less than 30% fixation losses, 30% false negative or 15% false positive errors.Main outcome measures; presence or absence of progression as evaluated subjectively by experts instructed to follow the European Glaucoma Society Guidelines (EGSG), where progression required confirmation in at least two fields, and presence, suspicion or absence of progression evaluated by the GPA algorithm where two black triangles with in the same scotoma were considered suspicious and three black triangles were considered progression. Coincidence in detection of progression was studied.

Results: : thirty-nine series of visual fields were finally considered. Fifteen were disregarded due to low reliability or baseline unavailability. Thirty-one patients (79.49%) showed confirmed absence of progression, 1 patient (2.56%) showed progression by GPA not confirmed by the expert evaluators, in one patient (2.56%) GPA failed to detect progression, in six patients (15.38%) GPA detected suspicion (1 case) or progression that was confirmed by experts.

Keywords: visual fields