Evaluation of Arteriovenous Crossing Sheathotomy for Branch Retinal Vein Occlusion by Fluorescein Videoangiography and Image Analysis

Abstract

Abstract: : Purpose:We quantitatively evaluated the effects of arteriovenous (A/V) crossing sheathotomy on retinal circulation in patients with branch retinal vein occlusion (BRVO) accompanied by macular edema.Methods:In 18 consecutive patients (18 eyes) with BRVO accompanied by macular edema, who underwent A/V crossing sheathotomy between August 1999 and April 2002, changes in circulation after the surgery were evaluated by fluorescein videoangiography with a scanning laser ophthalmoscope and by image analysis using dye dilution technique. At a venule distal to the responsible A/V crossing site and a normal venule, the circulation time (T₅₀) from the beginning of filling to 50% filling of the peak intensity was calculated. The time difference (ΔT₅₀) between the two points, which represents the delay in filling on the point distal to the A/V crossing site, was compared between before and early after the surgery. Results:The preoperative ΔT₅₀ was 1.36 ± 1.15 sec (mean ± SD), and the postoperative ΔT₅₀ was 0.72 ± 0.77 sec (p = 0.035). In 11 of the 18 eyes, ΔT₅₀ decreased by 20% or more after operation. In the other 7 eyes, ΔT₅₀ was unchanged or slightly increased after the surgery. Conclusions:Though a randomized controlled study is needed to confirm the effectiveness of A/V crossing sheathotomy on visual function, this technique could be effective for improving the delay in perfusion in the occluded venule, depending on the timing of surgery and the case selection.

Keywords: vascular occlusion/vascular occlusive disease • imaging/image analysis: clinical • vitreoretinal surgery