Macular capillary perfusion density and macular vessel density in open‐angle glaucoma and ocular hypertension: a quantitative study using optical coherence tomography angiography

Abstract

PurposeTo investigate macular vascular changes in patients with glaucoma and ocular hypertension, and to correlate these vascular parameters with structural and functional outcomes.MethodsA prospective observational study was performed with 46 open‐angle glaucoma eyes (GE), 35 ocular hypertension eyes (OHE) and 47 gender‐ and age‐matched control eyes (CE). Visual field tests were performed with the Humphrey Field Analyzer 3. Angioplex HD‐OCT Cirrus 5000 was used to capture the macular region using a 6 × 6 mm scan. Macular Capillary Perfusion Density (MPD) and Macular Vessel Density (MVD) were automatically quantified by the owner’s microangiography‐complex algorithm. The statistical analysis was performed using the Kruskal‐Wallis Test, Bonferroni Post Hoc analysis and Spearman rank correlation.ResultsMPD and MVD in GE were lower than those in OHE and CE (−37.32% and −37.09%), and the superior and inferior sectors were the most affected. In OHE, MPD and MVD were also lower when compared with CE (p < 0.001 for all pairwise comparisons). However, the FAZ was not significantly different between groups (p = 0.054). Regression analysis showed that MVD was moderately correlated with ganglion cell layer (r = +0.424), visual field mean deviation (r = +0.447) and retinal nerve fiber layer (r = +0.468). MPD had similar correlations (r = +0.431; +0.443 and +0.470, respectively). Superior and nasal sectors were the most correlated (p < 0.001 for all).ConclusionsData showed that in GE, vascular changes took place in the macular area, concretely MPD and MVD measurements were similarly reduced. This finding was not previously described and suggests that the vascular damage of the macular area may occur concurrently among large vessels and smaller capillaries. OHE measurements were also lower compared with CE, and this suggests that, at initial phases of the disease, vascular abnormalities may occur before structural damage can be detected. As MPD and MVD showed to be correlated with traditional glaucoma parameters, OCTA may be useful in the future to monitor glaucoma patients. Nevertheless, further research with larger population is needed to obtain stronger results.