Association of inflammatory factors with macular edema in branch retinal vein occlusion

To evaluate the association between vitreous fluid levels of inflammatory factors and macular edema in patients with branch retinal vein occlusion (BRVO).

In 39 patients with BRVO and macular edema and 21 individuals with idiopathic macular hole (MH) serving as controls, vitreous fluid samples were obtained during vitreoretinal surgery, and the levels of vascular endothelial growth factor (VEGF), soluble VEGF receptor 2 (sVEGFR-2), soluble intercellular adhesion molecule 1 (sICAM-1), interleukin 6 (IL-6), monocyte chemotactic protein 1 (MCP-1), pentraxin 3 (PTX3), and pigment epithelium-derived factor (PEDF) were measured by enzyme-linked immunosorbent assay. Macular edema was examined by optical coherence tomography.

Vitreous fluid levels of sVEGFR-2, VEGF, sICAM-1, IL-6, MCP-1, and PTX3 were significantly higher in the patients with BRVO than in those with MH; however, the PEDF level was significantly lower in the BRVO group. Vitreous fluid levels of all 7 factors were significantly correlated with the retinal thickness at the central fovea. There were also significant correlations of sVEGFR-2 with sICAM-1, IL-6, MCP-1, and PTX3 but no correlation with VEGF. However, there were significant correlations of VEGF with sICAM-1, IL-6, MCP-1, and PEDF in the BRVO group.

Vitreous fluid levels of sVEGFR-2, VEGF, sICAM-1, IL-6, MCP-1, PTX3, and PEDF are strongly correlated with retinal vascular permeability and the severity of macular edema in patients with BRVO. These findings may be useful for understanding macular edema and developing new treatments for BRVO.