A Study Evaluating Dosing Regimens for Treatment With Intravitreal Ranibizumab Injections in Subjects With Macular Edema Following Retinal Vein Occlusion

Inclusion Criteria: * For sexually active women of childbearing potential, use of an appropriate form of contraception (or abstinence) for the duration of the study. Ocular Inclusion Criteria (Study Eye) * Foveal center-involved macular edema secondary to branch retinal vein occlusion (BRVO) (including hemi-retinal retinal vein occlusion \[HRVO\]) or central retinal vein occlusion (CRVO). * Best corrected visual acuity (BCVA) using Early Treatment Diabetic Retinopathy Study (ETDRS) charts of 20/40 to 20/320 (Snellen equivalent) in the study eye. * Mean central subfield thickness \> 300 µm on 2 spectral-domain optical coherence tomography measurements (screening and Day 0 \[first day of treatment\]). Exclusion Criteria: * History of cerebral vascular accident or myocardial infarction within 3 months prior to Day 0. * History of any systemic anti-vascular endothelial growth factor (VEGF) or pro-VEGF treatment within 6 months prior to Day 0. * History of allergy to fluorescein. * History of allergy to ranibizumab injection or related molecule. * Relevant systemic disease that may be associated with increased systemic VEGF levels. History of successfully treated malignancies is not an exclusion criterion. * Uncontrolled blood pressure. * Pregnancy or lactation. * Daily use of oral corticosteroids to treat a chronic condition. * Required treatment with injectable corticosteroids to treat a musculoskeletal condition. * Participation in an investigational trial within 30 days prior to Day 0 that involved treatment with any drug or device that has not received regulatory approval at the time of study entry. Ocular Exclusion Criteria (Study Eye) * Prior episode of retinal vein occlusion (RVO). * Brisk afferent pupillary defect. * History of any previous intravitreal anti-VEGF therapy for RVO in the study eye. * History of previous therapeutic treatment for RVO, other than anti-VEGF therapy, within 4 months prior to the screening visit, including any intraocular corticosteroids. * History of previous surgical treatment for RVO, including radial optic neurotomy or sheathotomy. * History or presence of age-related macular degeneration (AMD) (dry form graded as Age-Related Eye Disease Study \[AREDS\] Stage 2 or higher or wet form). * History of laser photocoagulation for macular edema within 4 months prior to Day 0. * History of panretinal scatter photocoagulation or sector laser photocoagulation within 4 months prior to Day 0 or anticipated within the next 4 months following Day 0. * History of pars plana vitrectomy. * History of intraocular surgery within 2 months prior to Day 0 or anticipated within the next 7 months following Day 0. * History of yttrium-aluminum-garnet (YAG) capsulotomy performed within 2 months prior to Day 0. * Previous filtration surgery in the study eye. * History of herpetic ocular infection. * History of ocular toxoplasmosis. * History of rhegmatogenous retinal detachment. * History of idiopathic central serous chorioretinopathy. * Evidence upon examination of vitreoretinal interface disease either on clinical examination or spectral-domain optical coherence tomography (SD-OCT), thought to be contributing to macular edema. * Presence of an ocular condition that, in the opinion of the investigator, might affect macular edema or alter visual acuity during the study. * Visually significant hemorrhage obscuring the fovea and felt to be a major contributor to reduced visual acuity. The subject should be followed and when the hemorrhage in the fovea clears to the point that it is no longer a major contributor to reduced visual acuity, the subject may be screened for the study. * Presence of a substantial cataract that, in the opinion of the investigator, is likely to be decreasing visual acuity by 3 lines or more. * Intra-ocular pressure (IOP) ≥ 30 mmHg. If a subject's IOP is ≥ 30 mmHg, that subject will be referred for glaucoma treatment and may be re-screened after 1 month. * Evidence upon examination of pseudoexfoliation. * Aphakia. * Evidence upon examination of external ocular infection, including conjunctivitis, chalazion, or significant blepharitis. * Evidence upon examination of any diabetic retinopathy, defined as eyes of diabetic patients with more than one microaneurysm outside the area of the vein occlusion (inclusive of both eyes). * Other relevant ocular disease that may be associated with increased intraocular VEGF levels. * Improvement of ≥ 10 letters on best-corrected visual acuity ETDRS score between screening and Day 0.