Inclusion Criteria:  Patients ≥18 years old with type 1 or 2 diabetes mellitus with decreased BCVA due to center involving diabetic macular edema on spectral-domain optical coherence tomography. Patients with central macular thickness "CMT" of ≥ 300 micrometers  Exclusion Criteria:  Ocular conditions that may affect macular perfusion (e.g. retinal vascular diseases, uveitis, vasculitis etc.) History of vitreo-retinal surgeries. Previous macular laser treatment Presence of epi-retinal membrane involving the macula or vitreo-macular traction. Media opacity preventing good image quality. Uncontrolled glaucoma. Thrombo-embolic events within 6 months Previous intravitreal injections of anti-VEGF