Evaluation of retinal nonperfusion in branch retinal vein occlusion using wide‐field optical coherence tomography angiography

Purpose To characterize wide‐field optical coherence tomography angiography (OCTA) features of retinal nonperfusion in eyes with branch retinal vein occlusion (BRVO). Methods Automated scanning of five 12 × 12‐mm areas of swept‐source OCTA and wide‐field fluorescein angiography (FA) images was performed in a consecutive case series of 27 eyes in 27 patients with BRVO in this institutional cross‐sectional study. The correlation between the areas of retinal nonperfusion detected by both examinations was assessed. Panoramic images obtained in five 12 × 12‐mm OCTA scans in eyes with retinal nonperfusion were binarized or skeletonized, and the associations between vascular parameters such as vascular density (VD) and vascular length (VL) with the wide‐field FA characteristics were evaluated. Results The mean area of retinal nonperfusion in the OCTA images was 81.0 ± 66.8 mm2 (range, 0.0–188.8). The mean areas of retinal nonperfusion in FA and the total FA images were, respectively, 84.7 ± 72.5 mm2 (range, 0.0–221.9) and 184.1 ± 167.7 mm2 (range, 0.0–515.0). The mean VD was 27.6 ± 3.5% (range, 19.6–33.7), and the mean VL was 12.4 ± 8.5% (range, 5.4–31.3). Separate regression analyses of the areas of retinal nonperfusion in FA (p = 0.0004, R2 = 0.4627) and the total FA (p = 0.0008, R2 = 0.4214) images showed a significant association with the VL. Conclusions OCTA images based on wide‐field technologies can quantitatively evaluate retinal nonperfusion in eyes with BRVO.