Repeatability of Foveal Sensitivity Measured Using Adaptive Optics Microperimetry

Purpose: To assess the within and between-session repeatability of foveal sensitivity measurements using adaptive optics (AO) microperimetry. Methods: Five normal-sighted participants underwent AO microperimetry testing (550-nm circular stimulus) at the preferred retinal locus across two sessions (2 months ± 2 weeks). Two psychophysical paradigms were used: quick estimation of threshold (QUEST) and method of constant stimuli (MOCS). Each paradigm employed both 1.05-arcmin2 and 30.4-arcmin2 stimulus sizes; stimuli were not stabilized in real time. Trial-by-trial responses were fit with a logistic psychometric function to obtain thresholds at a criterion of 78% seen. Thresholds were converted to sensitivity. Statistical comparisons were performed using paired-sample t-tests. Results: Sensitivities measured from QUEST and MOCS procedures were not significantly different (QUEST: 1.05 arcmin2, P = 0.36 for session 1 and P = 0.41 for session 2; MOCS: 30.4 arcmin2, P = 0.14 for session 1 and P = 0.12 for session 2). Data were thus combined across paradigms for tests of repeatability. Sensitivities for data split into two groups within session 1 and separately within session 2 were not significantly different (QUEST: 1.05 arcmin2, P = 0.34 for session 1 and P = 0.51 for session 2; MOCS: 30.4 arcmin2, P = 0.31 for session 1 and P = 0.27 for session 2). Overall, sensitivities across the two sessions were not significantly different (QUEST: 1.05 arcmin2, P = 0.06; MOCS: 30.4 arcmin2, P = 0.81). The coefficients of repeatability across sessions were 1.5 decibels (dB) and 0.4 dB for 1.05 arcmin2 and 30.4 arcmin2, respectively. Conclusions: Sensitivity measurements from AO microperimetry were repeatable within and across sessions. Translational Relevance: Results of the present study will guide future longitudinal studies of disease progression in detecting sensitivity changes using AO microperimetry.