Interexaminer and intraexaminer reliability of the microperimeter MP-1

Purpose To evaluate the interexaminer and intraexaminer reliability of macular microperimetry using the microperimeter MP-1. Methods Participants: Fifteen healthy volunteers younger than 40 years of age (Group 1), 15 healthy subjects over 60 years (Group 2), and five patients with age-related macular degeneration (Group 3). Observation procedure: Two examiners (E1 and E2) measured, in random order, interexaminer (E2-E1a) reliability. Another examination was undergone by one of the examiners a week later to evaluate the intraexaminer (E1b-E1a) reliability. Main outcome measures: Macular sensitivity (mean threshold (decibel)) and stability of fixation were determined using MP1 microperimetry. Agreement was analysed by means of Bland-Altman plots and by the determination of the intraclass correlation coefficient. Results The interexaminer (E2-E1a) and the intraexaminer (E1b-E1a) differences in the mean threshold values were not statistically significant (P = 0.850, 95% confidence Interval (CI) = -0.265 to 0.319; P = 0.246, 95% CI = -0.099 to 0.375, respectively). Limits of agreement and intraclass correlation coefficients also showed good agreement in each group. Conclusions A good reliability was found for the mean threshold values in all the three groups, indicating examiner-independent measurements. Eye (2009) 23, 1052-1058; doi:10.1038/eye.2008.237; published online 1 August 2008