Roles and perspectives of inflammatory factors in diabetic macular edema

Abstract

Diabetic retinopathy is the leading cause of blindness in the working-age population, in which diabetic macular edema(DME)is the most common reason resulting in the vision impairment. Studies showed that inflammation factors play an important role in the pathogenesis and development of DME. Chronic hyperglycemia activates several biochemical pathways, leading to retinal hypoxia, oxidative stress and chronic inflammation. Intraretinal inflammation-related cells, such as microglia, monocytes/macrophages, Müller cells and retinal pigment epithelial cells, become activated and release a large number of inflammation-related factors and mediators, including the complement system, vascular endothelial growth factor(VEGF), placental growth factor(PlGF), tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), IL-6 and IL-8, etc., resulting in the breakdown of the blood-retinal barrier and neuronal degeneration. In addition, up-regulatethe expression of intercellular adhesion molecule-1(ICAM-1)and vascular cell adhesion molecule-1(VCAM-1)by retinal vascular endothelial cells increased the adhesion of leukocyte and leukostasis, further aggravating retinal hypoxia and breakdown of the blood-retinal barrier, leading to the increased retinal vascular leakage and macular edema. Therefore, early treatment with anti-VEGF and anti-inflammatory are pivotal for the treatment of DME. In this review, we will discuss the role of inflammation factors in the pathogenesis of DME and the research status of the targeted drugs targeting inflammation, so as to provide reference for the treatment of DME.

Keywords

• diabetic macular edema
• inflammatory cells
• inflammatory factors
• blood-retinal barrier
• macular edema