PURPOSE: To determine whether the glaucoma diagnostic accuracy of age- and Bruch membrane opening area (BMOA)-adjusted normative classifications of minimum rim width (MRW) and retinal nerve fiber layer thickness (RNFLT) is dependent on BMOA, in a European descent population. DESIGN: Retrospective, cross-sectional study. METHODS: We included 182 glaucoma patients and 166 healthy controls for the primary study, and 105 glaucoma patients in a second sample used for a replication study. Optical coherence tomography (Spectralis) measurements of BMOA, global MRW, and RNFLT and normative classifications from the device software were exported for analysis. Sensitivity and specificity were calculated for a conservative criterion (abnormal = "outside normal limits" classification) and a liberal criterion (abnormal = "outside normal limits" or "borderline" classifications). The dependence of sensitivity and specificity on BMOA was analyzed with comparison among subgroups divided by tertiles of BMOA, and with logistic regression. RESULTS: For the conservative criterion, MRW sensitivity was independent of BMOA (P ≥ .76), while RNFLT sensitivity increased in the large BMOA subgroup (P = .04, odds ratio: 1.2 per mm [P = .02]). For the liberal criterion, MRW and RNFLT sensitivities were independent of BMOA (P ≥ .53). Specificities were independent of BMOA (P ≥ .07). For the replication sample, which included younger patients with larger BMOA and worse visual field damage than the primary sample, sensitivities were independent of BMOA for both criteria (P ≥ .10). CONCLUSIONS: RNFLT sensitivity was higher in eyes with larger BMOA; however, age and visual field damage may influence that association. MRW diagnostic accuracy was not dependent on BMOA.
Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Canada; Department of Ophthalmology, University of São Paulo School of Medicine, São Paulo, Brazil.