The Effect of Bevacizumab and Ziv-aflibercept in Diabetic Macular Edema

Inclusion Criteria: * The patient at least 18 years old had type 1 or 2 diabetes who presented with Central DME involvement (defined as retinal thickening involving 1mm central sub field thickness(CCT) * Have at least a BCVA ( best corrected visual acuity) between 20/50 to 20/320 Snellen equivalent * Have received to anti-VEGF( anti -vascular endothelial growth factor) and laser treatment within the previous 3 months Exclusion Criteria: * Uncontrolled glaucoma/uncontrolled diabet , high risk PRP(pan-retinal photocoagulation), one eye * Prior treatment with intravitreal or peribulbar injection and laser therapy during the last 3 months * Substantial cataract, history of uveitis * Macular edema due to a cause other than DME * VMT(Vitreomacular traction ) and ERM (epiretinal membrane)