The blood-retinal barrier (BRB) alteration is the hallmark feature of diabetic retinopathy. Vascular endothelial growth factor (VEGF) is a potent vasopermeability factor that has been implicated in the pathogenesis of BRB alteration. Inflammation also plays a crucial role in this process with involvement of several chemokines and cytokines. Multiple anti-VEGF drugs are widely used as in the treatment of diabetic macular edema (DME) as well as proliferative diabetic retinopathy. Several clinical trials have proved the beneficial effects of these drugs in improvement of vision and prevention of vision loss. However, the response to anti-VEGF drugs in DME is not complete in a significant number of patients. The effect seems transient in this latter group, and many patients do not show complete resolution of fluid. Potential novel therapies targeting molecules beyond VEGF are being developed and examined in clinical trials.