Learning effect in visual field testing of healthy subjects using Humphrey Matrix frequency doubling technology perimetry

Abstract

Purpose To evaluate the learning effect of frequency doubling technology (FDT) perimetry using the Humphrey Matrix perimeter in healthy subjects with no perimetric experience.MethodsOne eye of 28 healthy adults who had no history of visual field testing underwent three Matrix tests using 24-2 programme with full-threshold strategy. The results of the first session were compared with those of the second, and the third sessions. Learning effect was defined as an improvement at results for duration, perimetric indices, and the number of points with a P < 5 and <1% in the total and pattern deviation maps. Anderson's criteria were applied to define abnormal examinations.ResultsThe mean in the mean deviation global index was 7.40 ± 1.49 dB in the first session, 4.64 ± 0.97 dB in the second session, and 3.29 ± 0.93 dB in the third session. Pattern standard deviations were decreased as the tests were repeated (P < 0.01). Test duration, fixation losses, false negative, and the number of points with a P < 5 and < 1% in the total and pattern deviation maps rate were also changed significantly (P < 0.05). Among the criteria suggested by Anderson, the Glaucoma Hemifield Test performed better in all session tests. The false-positive rates ranged from 50% (95% confidence intervals CI 30.6-69.4%) to 64% (95% CI 44.1-81.4%) for the first session, 29% (95% CI 13.2-48.7%) to 54% (95% CI 33.9-72.5%) for the second session, and from 18% (95% CI 6.1-36.9%) to 32% (95% CI 15.9-52.4%) for the third session.ConclusionsThe results of this study show that the learning effect for Humphrey Matrix FDT perimetry must be considered in normal individuals with no perimetric experience. © 2010 Macmillan Publishers Limited All rights reserved.