Abstract
Abstract: :
Purpose:: To evaluate arteriovenous (AV) crossing dissection for treatment of branch retinal vein occlusion (BRVO) with secondary macular dysfunction. Methods:Pars plana vitrectomy and dissection of the involved AV crossing site was performed consecutively in 20 eyes of 20 patients with BRVO and macular dysfunction resulting in visual acuity of 20/50 or worse. The overlying retinal artery was dissected free from the retinal surface and separation of the artery and vein at the offending crossing site was attempted. Indications included: macular edema with retinal hemorrhage precluding grid laser treatment (14 eyes), macular edema persisting after previous grid laser treatment (3 eyes), macular edema alone (2 eyes), and macular ischemia (1 eye). Median duration of symptoms was 16 weeks (range 6-156 weeks). Results:In 19 of 20 eyes, the retinal artery was dissected from the retinal surface around the crossing site, but a marked adhesion between artery and vein precluded separation. Operative findings correlated with histologic and cadaver eye studies relating to intervascular adhesion (Seitz; Tang and Han). After a mean follow-up of 10.2 months, VA improved by ≷2 lines in 16 eyes (80%), remained changed in 2 eyes (10%), and worsened by ≷2 lines in 2 eyes (10%). Mean change (+ S.E.) in logMAR was -0.28+.11 (2-3 lines improvement, p=.016) at 1-2 months follow-up and -0.44+.14 (3-4 lines improvement, p=.008) at final follow-up. Preoperative visual acuity was 20/20-20/50 in 5%, 20/60-20/160 in 40%, and 20/200 or worse in 55%. Final visual acuity was 20/20-20/50 in 50%, 20/60-20/160 in 25%, and 20/200 or worse in 25%. Cataract development or worsening was observed in 11 eyes (55%), requiring cataract surgery in 5 eyes (25%). Conclusion:Operative findings of surgical adhesion between retinal artery and vein at proximal arteriovenous crossings in living eyes correlated with previous histologic and cadaver eye studies. Technical aspects of arteriovenous crossing dissection must address this adhesion. Visual improvement may occur after vitrectomy and dissection of the AV crossing without separation of the vessels. A high rate of cataract formation may limit intermediate-term visual outcome.
Keywords: 628 vitreoretinal surgery • 615 vascular occlusion/vascular occlusive disease • 554 retina