AIM:To observe the efficacy and safety of intravitreal injection of Ranibizumab in the treatment of macular edema secondary to central retinal vein occlusion(CRVO).·METHODS:According to the standard,24 patients with macular edema secondary to CRVO were double- blind randomized to group I and group Ⅱ,They were aged 30-70 years old,average(51.58±10.32) years.Patients of group I were treated with intravitreal injection of 0.5mg ranibizumab monthly for the first three months and given compound thrombosis capsul...