Macular microvascular assessment in glaucoma: Tool output comparison and intersession reliability

To compare outputs and evaluate the intersession reliability of macular vascular metrics from the Erlangen-Angio (EA)-tool and the optical coherence tomography angiography vascular analyser (OCTAVA) Tool in glaucoma.

Ninety-three participants with open-angle glaucoma from the Individualised Perimetry Progression Observations in Glaucoma study were included. Macular 10° × 10° OCTA scans from the first two visits (113 ± 26 days apart) and central visual field sensitivities from the first visit were analyzed. Macular vessel density (VD) in four sectors (superior, nasal, inferior, and temporal), foveal avascular zone (FAZ) area, and circularity were quantified using the EA and OCTAVA tools using the same set of OCTA images. Linear mixed-effects models assessed tool-related differences across sectors and visits; reliability was assessed with repeatability coefficient (CRw), intraclass correlation (ICC), and coefficient of variation (CV); and linear regression examined associations between central visual field sensitivity and average VD.

OCTAVA reported higher VD estimates than the EA-tool overall, with a mean difference of 8.42% (p < 0.001). The CRw values for sectoral VD and FAZ metrics ranged from 0.09 to 7.65 for EA and 0.11-9.53 for OCTAVA, with overlapping ICC confidence intervals and comparable CV values between the two tools. Higher average VD was associated with better central visual field sensitivity (EA: β = 0.38; OCTAVA: β = 0.57; p < 0.001), where β denotes the regression coefficient.

OCTAVA consistently produced higher VD estimates than EA across macular sectors. VD showed good repeatability and strong structure-function associations, supporting its use for longitudinal monitoring. FAZ area demonstrated acceptable reliability. In contrast, FAZ circularity did not meet reliability criteria and should not be used for progression assessment with either tool.