Analysis of peripapillary vessel density and Bruch's membrane opening-based neuroretinal rim parameters in glaucoma
Philip Enders1, Valentina Longo2,3, Werner Adler4
1Department of Ophthamology, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Strasse 62, 50924, Cologne, Germany. philip.enders@uk-koeln.de.
Purpose:
To compare peripapillary vessel density (VD) measured by spectral domain optical coherence tomography angiography (SD-OCT-A) with morphometric parameters assessing the neuroretinal rim based on Bruch's membrane opening (BMO) by spectral domain optical coherence tomography (SD-OCT) in glaucoma.
Methods:
In this non-interventional cohort study, 50 eyes of 25 consecutively enrolled patients with diagnosis of glaucoma underwent SD-OCT and SD-OCT-A imaging of the optic nerve head (ONH). BMO minimum rim width (BMO-MRW) and area (BMO-MRA) as well as peripapillary retinal nerve fiber layer (RNFL) thickness were compared to peripapillary VD in the RNFL layer around the ONH.
Results:
Mean BMO-MRW was 221.46 ± 81.5 µm, mean BMO-MRA was 1.05 ± 0.04 mm2, mean RNFL thickness was 72.46 ± 23.16 µm, and mean VD was 43.8 ± 11.4%. VD was significantly lower when morphometric parameters had lower thickness values (p < 0.01). Correlation coefficients and their 95%- confidence intervals (95%-CI) with VD were r = 0.53 (95%-CI: 0.21-0.77) for BMO-MRW, r = 0.55 (95%-CI: 0.21-0.77) for BMO-MRA, and r = 0.57 (95%-CI: 0.13-0.73) for RNFL thickness. Intra-individual VD in both eyes correlated with r = 0.72 (p < 0.001), mean VD was comparable (p = 0.6). Eyes with high global RNFL thickness (>90 µm) showed less VD variance (σ2 = 48.1) compared to eyes with highly reduced RNFL thickness (<65 µm; σ2 = 82.0). Best corrected visual acuity, perimetric mean defect, and PSD correlated significantly with VD (95%-CI: -0.66 to -0.10, 0.16 to 0.6, and -0.65 to -0.02, respectively).
Conclusions:
Peripapillary vessel density measured by SD-OCT angiography correlates significantly with Bruch's membrane opening-based parameters measured by SD-OCT in glaucoma patients.
