Reproducibility of Microperimeter 3 (MP-3) Microperimetry in Open-Angle Glaucoma Patients

Primary open-angle glaucoma (POAG) is a chronic progressive optic neuropathy, leading to degeneration of retinal ganglion cells and characteristic morphological changes at the optic disc. In advanced stages of the disease, functional tests, such as standard automated perimetry (SAP), are the main diagnostic tools to detect progression. Compared to SAP, microperimetry offers fundus imaging with motion tracking to ensure precise stimulation of certain locations of the retina. Aim of the study was to assess reproducibility of microperimetry compared to SAP in patients with POAG.

This prospective monocenter study included patients suffering from POAG with visual field defects in the central 20° zone. After inclusion into the study, 3 consecutive study visits were scheduled within 1 month, assessing microperimetry and SAP at each visit.

From 19 patients recruited, data from 18 patients could be analyzed. No significant difference between study visits could be detected in mean retinal sensitivity in microperimetry and SAP (microperimetry p = 0.401; SAP p = 0.644; Friedman's 2-way analysis of variance). The intraclass-correlation coefficient was 0.981 (95% CI 0.978-0.984) for microperimetry and 0.948 (95% CI 0.941-0.955) for SAP. Absolute agreement between deep scotoma points was found in 81 test locations (79%) in microperimetry and in 35 test locations (20%) in SAP (p = 0.003, chi-square test).

Microperimetry and conventional perimetry showed high reproducibility, with slightly better performance of microperimetry. However, the reduced angle of visual field in microperimetry limits its application to central glaucomatous field damage.