The present study provided additional efficacy and safety data for 0.5-mg ranibizumab using as needed (PRN) dosing over 24 months in patients with visual impairment due to macular edema secondary to Central Retinal Vein Occlusion (CRVO). Spectral domain high-definition optical coherence tomography (OCT) images was analyzed to gain insights into predictive factors for disease progression and the possibility of reduced monitoring was assessed in Year 2. The results of this open-label study provided long-term safety and efficacy data to further guide recommendations on the use of ranibizumab in this indication.