Reproducibility of peripapillary, optic nerve head and macular vessel density by OCT-A according to glaucoma severity staging.

Objective: To assess the reproducibility of peripapillary, optic nerve head (PP-ONH) and macular vessel density (VD) by Spectral Domain optical coherence tomography angiography (SD OCT-A) in glaucoma patients and healthy subjects.

Methods: Cross-sectional study assessing 63 eyes of 63 subjects, including 33 glaucoma patients and 30 healthy subjects. Glaucoma was classified in mild, moderate, or advanced. Two consecutive scans were acquired by Spectralis Module OCT-A (Heidelberg, Germany), and provided images of the superficial vascular complex (SVC), nerve fiber layer vascular plexus (NFLVP), superficial vascular plexus (SVP); deep vascular complex (DVC), intermediate capillary plexus (ICP) and deep capillary plexus (DCP). VD (%) was calculated by AngioTool. Intraclass correlation coefficients (ICCs) and coefficients of variation (CV) were calculated.

Results: Among PP-ONH VD, better ICC presented advanced (ICC 0.86-0.96) and moderate glaucoma (ICC 0.83-0.97) compared with mild glaucoma (0.64-0.86). For the macular VD reproducibility, ICC results for superficial retinal layers were better for mild glaucoma (0.94-0.96) followed by moderated (0.88-0.93) and advanced glaucoma (0.85-0.91), and for deeper retinal layers ICC was better for moderate glaucoma (0.95-0.96) followed by advanced (0.80-0.86) and mild glaucoma (0.74-0.91). CVs ranged from 2.2% to 10.94%. Among healthy subjects, ICCs for the PP-ONH VD measurements (0.91-0.99) and for the macular VD measurements (0.93-0.97) were excellent in all layers, with CVs from 1.65% to 10.33%.

Conclusions: SD OCT-A used to quantify macular and PP-ONH VD showed excellent and good reproducibility in most layers of the retina, both in healthy subjects and in glaucoma patients regardless of the severity of the disease.