Purpose: The present study aimed to investigate the morphology of the retinal vasculature in eyes with branch retinal vein occlusion (BRVO) using optical coherence tomography (OCT) angiography.
Design: Observational case series.
Methods: Fluorescein angiography (FA) and OCT angiography were used to examine macular area and the retinal vasculature at the affected arteriovenous (AV) crossing in 46 patients with BRVO.
Results: FA revealed that the affected AV crossing pattern involved arterial overcrossing in 23 eyes (50.0%) and venous overcrossing in 11 eyes (23.9%). However, FA failed to detect the crossing pattern in 10 eyes (21.7%). OCT angiography was significantly more effective for identification of the AV crossing pattern than FA (44 eyes; 95.7%; P = .013). The number of eyes with venous overcrossing detected via OCT angiography (20 eyes, 43.5%) was also higher than that detected via FA (P = .047). OCT angiography revealed that venous narrowing (25.5 ± 21.1 μm) was significantly greater in instances of venous overcrossing than in those of arterial overcrossing (46.4 ± 23.7 μm, P = .005). Macular nonperfusion areas (NPAs) were larger in eyes with venous overcrossing than in those with arterial overcrossing (P = .011 for superficial plexus, P = .049 for deep plexus). The peripheral NPA was significantly larger in eyes with venous overcrossing (65.1 ± 35.3 disc area [DA]) than in those with arterial overcrossing (17.2 ± 24.1 DA; P < .001).
Conclusions: Our findings suggest that BRVO characterized by venous overcrossing may be more prevalent than previously reported, and that there is a significant association between NPA size and AV crossing pattern.
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