The role of inflammation in DME

The level of various inflammatory factors in the vitreous fluid is a significant factor in the severity of diabetic macular oedema (DME), according to study results published in the January issue of Ophthalmology.

Hideharu Funatsu, MD of the Tokyo Women's Medical University, Japan and colleagues conducted a retrospective case-control study of DME patients (n=53), patients with non-diabetic ocular disease (n=15) and diabetic patients who were free of retinopathy (n=8). The team examined samples of the vitreous fluid to determine levels of inflammatory factors, specifically vascular endothelial growth factor (VEGF), intercellular adhesion molecule (ICAM)-1, interleukin (IL)-6, monocyte chemotactic protein (MCP)-1, and pigment epithelium-derived factor (PEDF).

The researchers found that DME patients demonstrated significantly higher levels of VEGF, ICAM-1, IL-6 and MCP-1 when compared with other patient groups, although the level of PEDF was significantly lower in the vitreous of DME patients when compared with other patient groups. In addition, the levels of each of these inflammatory factors in the vitreous were associated with the thickness of the retina at the central fovea. VEGF and ICAM-1 had a greater influence on the severity of DME than IL-6, MCP-1 or PEDF.

The team concluded that the level of these inflammatory factors - particularly VEGF and ICAM-1 - in the vitreous correlate significantly to the permeability of the retina and the severity of DME.