Ozurdex Versus Ranibizumab Versus Combination for Central Retinal Vein Occlusion

Inclusion Criteria: * Adults greater than or equal to 18 years of age with foveal center involved macular edema secondary to CRVO diagnosed within 12 months before the screening visit (CRVO is defined as an eye with retinal hemorrhage or other biomicroscopic evidence of RVO \[eg telangiectatic capillary bed\] and a dilated \[or previously dilated\] venous system in at least 3 quadrants of the retina drained by the affected vein. * Best corrected visual acuity (ETDRS) letter score of 73 to 24 inclusive (20/40 to 20/320) in the study eye at Screening and at Day 1 * Mean central subfield thickness greater than or equal to 310 µm from 2 OCT measurements (Spectralis HRA + OCT) at Screening and Day 1 * Willing and able to comply with clinic visits and study-related procedures * Ability to provide signed informed consent form Exclusion Criteria: * History of vitreoretinal surgery in the study eye or anticipated within 12 months of Day 1 * Current bilateral manifestation of CRVO * Decrease in VA due to causes other than CRVO in the study eye * Prior episode of RVO in study eye * Afferent pupillary defect, obvious and unequivocal * Greater than 10 letter improvement in BCVA between Screening and Day 1 * History or presence of exudative or dry macular degeneration * Panretinal scatter photocoagulation or sector laser photocoagulation within 3 months prior to Day 1 or anticipated within 4 months after Day 1 * Anticipated laser photocoagulation for macular edema within 4 months after Day 1 * History of or evidence on examination of any diabetic retinopathy in the study eye * CVA or MI within 3 months prior to Day 1 * Prior anti-VEGF treatment in study or fellow eye within 3 months before day 1 or systemic anti-VEGF or pro-VEGF treatment within 6 months prior to Day 1 * Ocular or periocular infections including active or suspected viral diseases of the cornea and conjunctiva, active epithelial herpes simples keratitis (dendritic keratitis), vaccinia, varicella, mycobacterial infections, and fungal diseases * Glaucoma or current ocular hypertension requiring more than 1 medication to control IOP in the study eye or a history of steroid induced IOP increase in either eye * Prior Ozurdex treatment in study eye within 4 months prior to Day 1 * Aphakic eyes with rupture of posterior lens capsule * Anterior chamber IOL and rupture of posterior lens capsule * Hypersensitivity to any components of Ozurdex or Ranibizumab in either eye * History of other disease, metabolic dysfunction, physical exam finding, including renal failure on dialysis which renders the patient at high risk from treatment complications based on the judgment of the Investigator's at his/her discretion. * Sexually active men or women of childbearing potential who are unwilling to practice adequate contraception during the study (adequate contraceptive measures include stable use of oral contraceptives or other prescription pharmaceutical contraceptives for 2 or more menstrual cycles prior to screening; intrauterine device; bilateral tubal ligation; vasectomy; condom plus contraceptive sponge, foam, or jelly, or diaphragm plus contraceptive sponge, foam, or jelly).