A Clinical Study in Current Medical Practice of the Efficacy and Safety of Ranibizumab 0.5mg in Diabetic Patients Presenting a Visual Impairment Due to Macular Edema

Inclusion Criteria: * Male or female patients \>18 years of age who have signed an informed consent * Patients with Type 1 or Type 2 diabetes mellitus (according to ADA or WHO guidelines) with HbA1c not more than 10.0% at screening (Visit 1). Patients should be on diet, exercise, and/or pharmacological treatment for diabetes. * Patients with visual impairment due to focal or diffuse DME in at least one eye * Central Retinal thickness on OCT ≥ 250 microns in the central subfield * BCVA score between 78 and 39 letters, inclusively, using ETDRS-like visual acuity testing charts at a testing distance of 4 meters (approximate Snellen equivalent of 20/32 to 20/160) * Decrease in vision is due to DME and not due to other causes, in the opinion of the investigator * Medication for the management of diabetes must have been stable within 3 months prior to randomization and is expected to remain stable during the course of the study. Exclusion Criteria: Ocular concomitant conditions/ diseases * Concomitant conditions in the study eye which could, in the opinion of the investigator, prevent the improvement of visual acuity on study treatment * Active intraocular inflammation (grade trace or above) in either eye * Any active infection (e.g. conjunctivitis, keratitis, scleritis, uveitis, endophthalmitis) in either eye * History of uveitis in either eye Systemic conditions or treatments * Active systemic infection * History of stroke \< 3 months * Renal failure requiring dialysis or renal transplant OR renal insufficiency with creatinine levels \> 2.0 mg/dl * Untreated diabetes mellitus * Blood pressure systolic \> 160 mmHg and diastolic \> 100 mmHg * Untreated hypertension * Known hypersensitivity to ranibizumab or any component of the ranibizumab formulation Others * Women of childbearing potential not using the contraception method(s) specified in this study (specify), as well as women who are breastfeeding Other protocol-defined inclusion/exclusion criteria may apply