ABSTRACT
Branch retinal vein occlusion (BRVO) is the second most common vascular cause of reduced visual acuity after diabetic eye disease. BRVO is characterized by dilated and tortuous veins, flame and blot-shaped hemorrhages, retinal edema, and cottonwool spots in the area of retina drained by the obstructed vein. As there is a common adventitial sheath at sites of arteriovenous (AV) crossing, the enlargement of the arteriole results in compression of the lumen of the vein. The resultant turbulent flow through the vein, endothelial damage, and secondary thrombus formation lead to vessel occlusion. M. D. Osterloh and S. Charles first developed a technique for decompression of an AV crossing with the intention of restoring adequate venous drainage in eyes that do not either adequately recanalize the affected vein or develop sufficient collateral circulation. When the AV crossing site is reached, a side-to-side movement of the microvitreoretinal blade is used to cut the common adventitial sheath.
