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.