The learning effect in Humphrey Field Analyser testing in glaucoma patients: how many practice sessions are enough?

Abstract

Purpose: The learning effect is an essential factor in many psychophysical tests. This study aims to examine the learning effects of Humphrey Field Analyser (HFA) in patients with glaucoma.Study design: Cross-sectional study.Methods: Twenty eyes of 12 patients (10 patients [83.4%] open-angle glaucoma, 1 patient [8.3%] angle-closure glaucoma, and 1 patient [8.3%] secondary glaucoma) were sent to HFA examination for three different sessions of examination. The inclusion criteria were patients with glaucoma who completed three HFA examinations.The results were analysed using ANOVA and Tukey’s post hoc test. The primary outcomes were reliability, global indices, and the threshold sensitivity between the three sessions.Results: Duration to complete the HFA test statistically decreased after the third session (first vs third session: 387 ± 96 vs 307 ± 93 sec; p = 0.017) as well as fixation loss (first vs third session: 0.25 ± 0.19 vs 0.05 ± 0.11: p = 0.001). False-negative results improved after the third session (first vs third session: 0.15 ± 0.15 vs 0.02 ± 0.03 p < 0.001). There was no statistically significant difference in false-positive, mean deviation, pattern standard deviation, and visual field index within the three sessions.Conclusions: There was shorter test duration, decreased fixation loss, and decreased false negatives in the third session of HFA, but there was no statistically significant change to the global indices. Experience has important effect on perimetry results. Thus, the learning effect should be taken into consideration for management ofpatients with glaucoma.