Robustness of automated Bruch’s membrane opening minimum rim width and retinal nerve fiber layer thickness without clinical disc margin adjustment in glaucoma
摘要
To evaluate the structure-structure correspondence between circumpapillary retinal nerve fiber layer (cpRNFL) thickness and Bruch’s Membrane Opening Minimum Rim Width (BMO-MRW) in primary open-angle glaucoma (POAG) and controls, and to assess the impact of manual realignment to the clinically visible optic nerve head (ONH) margin.
MethodsIn this cross-sectional study, spectral-domain optical coherence tomography measured BMO-MRW at 48 radial positions and the 3.5-mm cpRNFL thickness. The Spectralis normative database was used to confirm sectoral MRW and cpRNFL correlation in a large, independent dataset within Garway-Heath sectors. An internal anatomical reference curve of MRW–cpRNFL differences was constructed from 36 eyes with concordant automated and clinically adjusted ONH margins. Subsequently, 116 eyes (72 control, 44 POAG) with margin discordance were analyzed to determine whether manual realignment by two examiners improved correspondence with the reference curve, using squared Spearman correlation (rho²).
ResultsAutomated BMO-MRW and cpRNFL showed significant sectoral correlation (maximum r = 0.44, inferotemporal; p < 0.001), with excellent interobserver agreement (ICC 0.99 controls, 0.96 POAG). In controls, automated curves were closer to the reference than manual realignment (9.9 ± 9.8 μm vs. 27.7 ± 16.1 μm; p < 0.0001; rho²=0.96 vs. 0.91). In POAG, manual realignment reduced mean deviation from the reference (− 99.7 ± 37.7 μm vs. − 124.3 ± 30.4 μm; p < 0.0001). Nevertheless, automated segmentation retained stronger monotonic association (rho²=0.82 vs. 0.57), indicating better structural correspondence. Realignment offered minimal benefit in inferotemporal sectors.
ConclusionsAutomated BMO-based segmentation demonstrates consistent structure-structure correspondence with cpRNFL in healthy and glaucomatous eyes. Manual realignment yields limited benefit in relatively preserved rim sectors and adds little value in routine glaucoma assessment.