Purpose: To evaluate visual outcome after arteriovenous (AV) crossing dissection for the treatment of branch retinal vein occlusion (BRVO) and secondary macular dysfunction in which difficulty separating the retinal vessels was experienced.
Methods: A pars plana vitrectomy and dissection of the involved AV crossing site were performed consecutively in 20 eyes of 20 patients with BRVO and vision loss. The overlying retinal artery was dissected free from the retinal surface, and separation of the artery and vein at the crossing site was attempted.
Results: In 19 of 20 eyes, the retinal artery was dissected around the crossing site, but a marked adhesion between the artery and vein precluded separation. After a mean follow-up of 10.5 months, VA improved by at least two lines in 16 eyes (80%), remained unchanged in three eyes (10%), and worsened by at least two lines in three eyes (10%). Mean change (+/- SE) in logMAR acuity was -0.28 +/- 0.11 (two or three lines of improvement, P = 0.016) at 1 to 2 months' follow-up and -0.44 +/- 0.14 (three or four lines of improvement, P = 0.008) at the final follow-up. Cataract formation or progression occurred in 88%.
Conclusions: A surgically important adhesion between the retinal artery and vein at proximal AV crossings was encountered in all eyes undergoing AV crossing dissection, correlating with previous histologic and cadaver eye studies. Cataract formation or worsening was a frequent complication. Visual improvement may occur after vitrectomy and AV crossing dissection without separation of the retinal vessels.