Intrasession Repeatability and Intersession Reproducibility of Macular Vessel Parameters on Optical Coherence Tomography Angiography in Glaucomatous and Non-Glaucomatous Eyes

Abstract

Purpose: Using optical coherence tomography angiography (OCTA), this study compared intrasession repeatability versus intersession reproducibility of macular vessel parameters in glaucoma and non-glaucoma subjects.

Methods: 6 × 6 mm² macular OCTA scans (Cirrus HD-OCT 5000) were acquired from glaucomatous and non-glaucomatous subjects as part of an observational, longitudinal study. Vessel area density (VAD) and vessel skeleton density (VSD) were calculated using research-based quantification software while perfusion density (PD_Z) and vessel density (VD_Z) were calculated using commercially developed software (Cirrus 11.0, Carl Zeiss Meditec). Intrasession repeatability and intersession reproducibility were determined using within-eye standard deviation (S_W), within-eye coefficient of repeatability (CR_W), within-eye coefficient of variation (CV_W), and intraclass correlation coefficients (ICC).

Results: The intrasession repeatability and intersession reproducibility for macular OCTA parameters were similar to one another for both non-glaucomatous and glaucomatous eyes. Intrasession CV_W from the non-glaucoma group (n = 73) was 1.097% for VAD, 1.007% for VSD, 2.980% for PD_Z, and 2.714% for VDZ. Intersession CV_W from the non-glaucoma group (n = 55) was 1.389% for VAD, 1.279% for VSD, 2.935% for PD_Z, and 2.695% for VD_Z. Intrasession CV_W from the glaucoma group (n = 59) was 1.189% for VAD, 0.970% for VSD, 3.827% for PD_Z, and 3.542% for VD_Z. Intersession CV_W from the glaucoma group (n = 45) was 1.412% for VAD, 1.132% for VSD, 3.915% for PD_Z, and 3.654% for VD_Z. Non-glaucomatous intrasession ICC ranged from 0.711 to 0.824, non-glaucomatous intersession ICC ranged from 0.649 to 0.762, glaucomatous intrasession ICC ranged from 0.710 to 0.853, and glaucomatous intersession ICC ranged from 0.661 to 0.827.

Conclusions: Macular OCTA scans can be a useful tool in monitoring the longitudinal progression of glaucoma due to their high repeatability and reproducibility.

Keywords: Glaucoma; OCTA; macula; optical coherence tomography angiography; repeatability and reproducibility.