Pathophysiology of diabetic macular edema – a background for current treatment modalities

Introduction: Diabetic macular edema is a sight-threatening disease and a major cause for blindness for people in working age. The pathogenesis or pathophysiology of this condition is multifactorial and different pathways have been identified, such as inflammation, the modulation of vascular integrity and tractional forces at the vitreomacular interface. Considering the significance of these pathogenetic mechanisms as the main targets in the modern treatment of diabetic macular edema, the current review aims to provide a detailed insight in the current understanding regarding these pathways. Areas covered: This review discusses original research articles including basic science and clinical studies as well as review articles focusing on inflammation, the vascular endothelial growth factor (VEGF) pathway and the role of the vitreomacular interface. The literature was searched using Medline/PubMed and articles were selected given their relevance for the topic to be discussed. Expert commentary: In recent years, knowledge regarding the pathophysiology of diabetic macular edema has significantly increased. Several interacting pathways with multiple growth factors, cytokines, cellular responses and so on, have been identified. Some of these insights have been successfully transferred into current treatment strategies already, such as VEGF suppression or anti-inflammatory treatments using steroids. It will be a future challenge not only to further identify additional pathophysiological aspects, but also to better understand their interactions and relevance as potential treatment targets and potential combinations.