Cytokine concentration in aqueous humor of eyes with diabetic macular edema.

Purpose

To measure cytokine concentrations in aqueous humor of eyes with diffuse diabetic macular edema.

Methods

The interventional clinical comparative study included a study group of 23 patients with diffuse diabetic macular edema and a control group of 22 patients undergoing cataract surgery. Cytokine concentrations were measured in aqueous humor samples using a Luminex xMAP suspension array technology.

Results

In the study group as compared with the control group, significantly higher concentrations were measured for epidermal growth factor (P < 0.001), human growth factor (P < 0.001), intercellular adhesion molecule-1 (ICAM-1; P < 0.001), interleukin (IL)-1a2 (P = 0.04), IL-6 (P = 0.001), IL-8 (P < 0.001), interferon gamma-induced protein (P = 0.004), monocyte chemoattractant protein-1 (P < 0.001), monokine induced by interferon gamma (P < 0.001), matrix metalloproteinase 1 (P = 0.02), matrix metalloproteinase 9 (P < 0.001), plasminogen activator inhibitor 1 (P < 0.001), placenta growth factor (P < 0.001), tissue growth factor beta (P = 0.003), vascular cell adhesion molecule (P < 0.001), and vascular endothelial growth factor (P < 0.001). Retinal macula thickness was significantly associated with the concentrations of the epidermal growth factor (P = 0.005; ρ = 0.45), ICAM-1 (P < 0.001; ρ = 0.65), IL-3 (P = 0.002; ρ = 0.48), IL-6 (P = 0.003; ρ = 0.47), IL-8 (P < 0.001; ρ = 0.71), monocyte chemoattractant protein-1 (P = 0.001; ρ = 0.53), monokine induced by interferon gamma (P < 0.001; ρ = 0.57), matrix metalloproteinase 9 (P < 0.001; ρ = 0.61), tissue growth factor beta (P = 0.01; ρ = 0.42), placenta growth factor (P = 0.004; ρ = 0.46), vascular cell adhesion molecule (P = 0.006; ρ = 0.44), and vascular endothelial growth factor (P = 0.01; ρ = 0.42). In multivariate analysis, macular thickness remained to be significantly associated with the concentration of ICAM-1 (P = 0.03; r = 0.30). Vascular endothelial growth factor concentrations were correlated with concentration of placenta growth factor (P < 0.001; ρ = 0.78), plasminogen activator inhibitor 1 (P = 0.001; ρ = 0.54), ICAM-1 (P < 0.001; ρ = 0.47), monokine induced by interferon gamma (P = 0.004; ρ = 0.44), monocyte chemoattractant protein-1 (P = 0.003; ρ = 0.43), vascular cell adhesion molecule (P = 0.01; ρ = 0.38), IL-6 (P = 0.02; ρ = 0.35), IL-8 (P = 0.02; ρ = 0.37), epidermal growth factor (P = 0.01; ρ = 0.39), and macrophage migration inhibitory factor (P = 0.01; ρ = 0.37).

Conclusion

Numerous cytokines are associated with the presence and the amount of diabetic macular edema. Among these cytokines, ICAM-1 was the most significantly associated with the disease parameters.