Controversies in the pathogenesis of RVO – Local perspective

AbstractBRVO usually occurs at an arteriovenous (AV) crossing site, where a common adventitial sheath binds the artery and vein together. Several findings seem to demonstrate that vitreoretinal traction might have a significant role in some cases of BRVO. This prospective observational case‐control study, with SD‐OCT directed to the occlusion site, analyzed the prevalence of vitreoretinal traction in twenty BRVO patients. The results showed a true vitreoretinal traction in 7 eyes (35%). 5 eyes (25%) were associated with an adherence of posterior hyaloids without signs of retinal traction, whereas 8 eyes (40%) had neither vitreoretinal adherence nor vitreous traction. Regarding the same vessel segment of the fellow eye, none of the cases (0%) revealed vitreoretinal traction in the correspondent AV crossing site; 9 cases (45%) presented vitreoretinal adherence; and the remaining 11 cases (55%) showed neither traction nor adhesion. Chi‐square analysis indicated that vitreovascular traction in the occlusion site was significantly associated with BRVO (p<0.05). In conclusion, a common firm vitreoretinal adhesion at the obstruction site is reported herein, pointing out the role of vitreovascular traction in the etiology of some cases of BRVO.