Comparison of conventional and pattern discrimination perimetry in a prospective study of glaucoma patients

PURPOSE. To determine whether pattern discrimination perimetry detects progression of glaucomatous visual fields earlier than conventional static automated perimetry. METHODS. One hundred nine eyes of 109 patients with open angle glaucoma were enrolled in a longitudinal prospective study. Each patient underwent visual field examinations with conventional and pattern discrimination perimetry using the 30-2 program of the Humphrey Visual Field Analyzer (Humphrey Instruments Inc., San Leandro, CA) and a custom program for the pattern discrimination perimeter, respectively at 6-month intervals. Progression of glaucomatous visual field damage was assessed separately at each visit by predetermined criteria for conventional and pattern discrimination perimetry. The time to progression from baseline was calculated and the hemifield that showed progression first was documented for both conventional and pattern discrimination perimetry. RESULTS. Patients were followed for a mean of 5.1 years and a mean of 11.6 visits. Sixty-eight (62.3%) patients did not show progression with either technique. Of the remaining 41 patients, 15 (36.5%) showed progression with conventional perimetry alone, 9 (21.9%) with pattern discrimination perimetry alone, and 17 (41.4%) showed progression with both techniques. Of these 17 patients, 11 (64.7%) were detected earlier by conventional perimetry, and 6 (35.2%) were detected earlier by pattern discrimination perimetry. CONCLUSIONS. This study suggests that pattern discrimination perimetry is less effective than conventional perimetry in evaluating progressive glaucomatous visual field damage.