A Study on Arteriovenous Crossing Sites in Branch Retinal Vein Occlusion

ABSTRACT

Retinal arteriovenous crossing sites are important because they are generally the points at which. in branch retinal obstruction, a blockage of venous blood flow occurs. We evaluated retrospectively the cases of 54 patiens wIth a recent temporal branch retinal vein occlusion to determine the relative anatomic position of the obstructed vein in relation to its crossing artery. In 54 (100%) of 54 eyes, the artery lay antenor to the vein, toward the vitreous cavity. In the control corssing site, the artery lay anterior to the vein 41.3% (J9/46) of the time (p<0.01) The second control group, which was obtained by examining all of the first-and second-order, without BRVO, consisted of 103 crossing sites. In this second control group's artenovenous crossmgs, the arteries were situated anteriorly in 83 (80.6%) of 103 crossing sites (p<0.005). Our observation that the artery lies anterior to the vein at the all of BRVO crossing sites contributes further evidence that mechanical factors play a prominent role in the causing BRVO.