Clinical Ophthalmology (Apr 2017)
Intersession test–retest variability of 10-2 MAIA microperimetry in fixation-threatening glaucoma
Abstract
Evan N Wong,1,2 William H Morgan,1,3 Fred K Chen1,3 1Centre for Ophthalmology and Visual Science (Incorporating Lions Eye Institute), The University of Western Australia, 2Department of Ophthalmology, Sir Charles Gairdner Hospital, 3Department of Ophthalmology, Royal Perth Hospital, Perth, WA, Australia Purpose: To determine the intersession test–retest variability (TRV) of CenterVue Macular Integrity Assessment (MAIA) microperimeter in glaucoma patients with fixation-threatening field defects.Methods: This is a prospective case–control study of 27 participants consisting of 13 patients with stable primary open-angle glaucoma and 14 control subjects including 5 healthy individuals and 9 retinal patients (5 with non-neovascular age-related macular degeneration and 4 with inherited retinal disease). Each participant underwent three microperimetry tests in one eye at 1-month intervals. Each test used an identical test strategy of 10-2 Cartesian grid and 4-2 staircase algorithm. We investigated TRV by calculating the coefficient of repeatability (CR) for mean sensitivity (MS) and point-wise sensitivity (PWS) for glaucomatous subjects and retinal and normal subjects. 95% confidence intervals (CIs) for CRs were calculated.Results: There was no significant change in MS, and the median durations of microperimetry sessions were 9´26ˮ, 8´52ˮ, and 8´46ˮ across the three study visits. The intersession CRs for MS were 1.1, 2.5, and 1.8 dB, and the average CRs for PWS were 3.5, 7.4, and 8.6 dB for healthy controls and retinal and glaucoma patients, respectively. For test loci with 25–34 dB at baseline, CRs for PWS were 8.2 (95% CI: 7.5–8.9) and 4.3 (95% CI: 4.0–4.6) dB for glaucoma and control subjects, respectively.Conclusion: We found differences in TRV of test loci depending on the baseline sensitivity value. Glaucoma patients had significantly worse TRV for loci that had sensitivity values within the normal range at baseline. The estimated CR has implications for sample size calculation in future glaucoma treatment trials using microperimetry as a clinical endpoint. Keywords: microperimetry, MAIA perimeter, glaucoma, retinal dystrophy, optic neuropathy
