Ozurdex for Diabetic Macular Edema Treated With Pars Plana vitrEctomy and Membrane RemovAl (OPERA Study)

Inclusion Criteria: 1. Patients who are undergoing pars plana vitrectomy for: * Epiretinal membrane/vitreomacular traction or * Diabetic macular edema 2. Patients with macular edema as measured by OCT (at least 250 um central subfoveal thickness) 3. Informed consent requirements: All study subjects must agree to participate in the study and provide written informed consent, which will be written in English. 4. Age between 18-85 years old Exclusion Criteria: 1. Age \< 18 years or \> 85 years 2. History of macular edema due to diseases other than those in the inclusion criteria in the study eye * History of active inflammatory eye disease (uveitis) (within 3 months) * History of ocular malignancy and/or ocular/orbital irradiation * History of recent retinal vein occlusion (within 6 months) * History of neovascular age-related macular degeneration or choroidal neovascular membrane \[ * History of juxtafoveal telangiectasia * History of Coat's disease * History central serous choroidoretinopathy * History of previous infectious retinitis (toxoplasmosis, acute retinal necrosis, tuberculosis, etc) 3. Patients with a history of intraocular infection in the study eye (i.e. viral retinitis, endophthalmitis) 4. Patients who are cognitively impaired or those who are unable to provide informed written consent 5. Patients with a history of glaucoma in the study eye (defined as increased cup to disc ratio with associated nerve damage. Patients with ocular hypertension controlled by topical glaucoma drops (maximum 3) will not be excluded). 6. Patient with recent intravitreal injections of steroids or anti-VEGF medications in the study eye (within past 4 weeks). 7. Patients with recent periocular steroid injection (within past 4 weeks) in the study eye 8. Patients on topical NSAIDS drops (patient will be eligible if they discontinue use of topical NSAIDs at time of study enrollment) in the study eye