Improvement of Venous Blood Flow Measured by LSFG After Arteriovenous Sheathotomy Leads to Reduction of Macular Edema

Abstract

Purpose: : To evaluate whether the reperfusion of the occluded retinal vein confirmed by measurement of the blood flow volume using the Laser Speckle Flowgraphy (LSFG) may reduce the macular edema and improve the visual acuity (VA) after arteriovenous sheathotomy in eyes with a branch retinal vein occlusion (BRVO).

Methods: : Our group recently proposed that LSFG might be useful to quantitatively evaluate that the procedure of arteriovenous sheathotomy decompresses the mechanical pressure in the arteriovenous crossing site of a BRVO and can improve the blood flow volume in the retinal vein (2008 ARVO meeting). In this study we analyzed 4 eyes of 4 patients with a BRVO in whom a restoration of downstream blood flow was obtained during the surgery with arteriovenous sheathotomy. None of the patients were given triamcinolone acetonide during the surgery. Two measurement points by LSFG were selected at the retinal vein proximal to the arteriovenous crossing site and the non-affected retinal vein. The relative flow volume, expressed with mean blur rate (MBR), was measured by LSFG within 24 hours before the surgery, on 7 days and 1 month after the surgery. The VA in logMAR units and macular edema as evaluated by OCT were measured before and at 3 months after the surgery in all of the cases.

Results: : At 7 days and at 1 month after the surgery, the blood flow volume of the vein treated by the arteriovenous sheathotomy was higher than the preoperative value in all of cases. In all of the eyes, the macular edema was significantly decreased from 505±144µm before the surgery to 265±79µm at 3 months after the surgery (p=0.003). Improvement in the VA=0.2 logMAR units was confirmed in 2 of 4 eyes at the same time point.

Keywords: vascular occlusion/vascular occlusive disease • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • vitreoretinal surgery