Systemic contribution of inflammatory mediators to the severity of diabetic and uveitic macular edema

To assess whether serum cytokine and growth factor levels are associated with diabetic macular edema (DME) and uveitic macular edema (UME) objective severity.

Cross-sectional observational study of 81 patients (1 eye/patient) with DME (n=48) and UME (n=33). Macular edema (ME) was defined upon central macular thickness (CMT) ≥ 300 μm on spectral domain optical coherence tomography (OCT). Serum samples were obtained from peripheral blood and IL-1β, IL-6, IL-8, IL-10, MCP-1, TNF-α, and VEGF levels were determined by Luminex analysis. Main outcome measure was the correlation between mediators' levels and CMT and macular volume (MV) on OCT for ME cases.

In DME, IL-6 levels were found to significantly correlate with MV (r=0.324; p=0.028) whereas in UME, IL-8 was significantly associated with both CMT (r=0.401; p=0.021) and MV (r=0.391; p=0.024). IL-8 independently correlated with CMT (ß=177.2; p=0.033) and MV (ß=3.17; p=0.008) in UME multivariate model.

Peripheral blood IL-6 and IL-8 levels could play a role in the severity of DME and UME, respectively. IL-8 even seems to be independently associated with CMT and MV in UME cases. Such systemic implications could enforce DME and UME personalized diagnostic and therapeutic approaches.