Radial Optic Neurotomy in Central Retinal Vein Occlusion : a Randomized Trial

Inclusion Criteria: * Central Retinal Vein Occlusion oedematous or hemorrhagic (at fundus exam and at fluorescein angiography) * Visual Acuity (VA) ≤ 20/200 with ETDRS charts * Decreased VA since more than 1 month, less than 3 months * Common care recommendations for CRVO during the period before recruitment (Control ocular pressure if associated hypertension or glaucoma ; Hemodilution if hematocrit ≥ 38% ,if no cardio-vascular contra-indication, to maintain hematocrit under 38% during 6 weeks ; Troxerutin (3 /d) and aspirin (100 - 160 mg/d) ; Clinical and angiographic controls to look for retinal ischemia indicating laser PRP to prevent neovascular glaucoma. * Signed informed consent. Exclusion Criteria: * Ischemic CRVO : 1- More than 30 disc diameters of ischemia at fluorescein angiography and/or •2- If Angiogram is uninterpretable because of hemorrhages, deficit of afferent pupillary reflex 0.9 with photographic filters (proposed by Hayreh) with indication to do laser PRP or laser PRP already done, * Rubeosis or neovascular glaucoma, * Bilateral diabetic retinopathy preproliferative or proliferative, * Uncharacterized coagulation disease, or anticoagulant treatment, * Untreated systemic disease (diabetes, severe high blood pressure, Cardiac failure) ou eye disease (glaucoma), * Contra-indication or documented allergy to troxerutin or platelet anti-aggregating agents, * Contra-indication to surgical procedure * incapacity to received an informed consent, incapacity to follow all the study schedule