Emerging pharmacotherapies for diabetic macular edema

Diabetic macular edema (DME) is the most frequent cause of severe vision impairment in patients with non-proliferative diabetic retinopathy. Even though patients should achieve optimal glycemic control, normalization of blood pressure and serum lipids, as well as improvement of cardiac and renal status, these measures alone will not prevent every patient from developing visual loss caused by DME. The goal of local treatment for DME is vision improvement, usually achieved after reducing leakage on fluorescein angiography (FA) and retinal thickness on optical coherence tomography (OCT). Laser photocoagulation is still the standard treatment for clinically significant DME. However, laser photocoagulation rarely provides major visual improvement, especially in patients with diffuse DME. Thus, a therapeutic intervention that restores visual acuity impaired by DME more often remains a significant unmet medical need. This review aims to present the most important emerging drug technologies for therapy of DME at present, including corticosteroids, vascular endothelial growth factor inhibitors, protein kinase C inhibitors, small interfering RNA, hydroxy-3-methyl-glutaryl coenzyme A reductase inhibitors and non-hormonal anti-inflammatory agents. Recent progress in this field suggests that local management of DME may change rapidly in the near future. Novel emerging drugs should enable better anatomical and functional outcomes for therapy of this sight-threatening disease.