Treatment for Central Retinal Vein Occlusion: Radial Optic Neurotomy vs. Conservative Therapy. One Year Follow-up

The aim of this study was to evaluate in a prospective nonrandomised way the long-term effectiveness and safety of the surgical technique consisting in pars plana vitrectomy and radial optic neurotomy as therapy for central retinal vein occlusion (CRVO) compared with conservative treatment. In addition, we wanted to compare the effects of surgery in ischemic and non-ischemic CRVO and evaluate the influence of chorioretinal anastomosis (CRA) on retinal perfusion and visual acuity. Twenty-eight patients (group A) underwent pars plana vitrectomy and radial optic neurotomy (RON) and 35 patients (group B) were conservatively treated and followed as control. In the surgery group were included eyes with VA of 0,3 or worse. Visual acuity, retinal perfusion, time of arteriovenous transit on fluorescein angiography and development of chorioretinal anastomosis were analised at onset and one year after treatment. The initial mean visual acuity in group A was 0,1 and 0,23 in group B. After 1 year, patients in group A experienced a mean gain of lines of 2,51 compared with 0.60 in group B (significant only in group A). Similarly, time of arteriovenous transit improved significantly only in group A. Development of chorioretinal anastomosis was much higher after RON (57%) than in the conservative group (5,7%). In both groups the development of CRA correlated with a better visual recovery. Non-ischemic and hemorrhagic CRVO showed a greater functional improvement after RON than ischemic CRVO. The incidence of complications and the need for an additional treatment were signficantly lower in group A. In our study, compared with a conservative therapy, RON shows a better improvement of visual acuity and retinal perfusion in patients with CRVO, specially in those eyes with a non-ischemic or hemorrhagic occlusion and initially poor vision who have, otherwise, a low chance of significant spontaneous visual recovery. The development of chorioretinal anastomosis may play an important role in the improvement of retinal perfusion and visual function