Anti-VEGF Therapy Reduces Inflammation in Diabetic Macular Edema

Purpose: Correlations among the aqueous flare value (an indicator of inflammation), several functional-morphologic parameters, and aqueous humor levels of multiple cytokines or inflammatory factors were investigated in patients with diabetic macular edema (DME) receiving intravitreal rani­bizumab injection (IRI). Methods: Aqueous humor levels of 12 cytokines, growth factors, or inflammatory factors were measured in 46 DME patients who received IRI. Vascular endothelial growth factor (VEGF), soluble VEGF receptor (sVEGFR), and the other cytokines/inflammatory factors were measured by the suspension array method. In addition, aqueous flare values were measured with a laser flare meter, and central macular thickness (CMT) was examined by optical coherence tomography. Results: At 1 month after IRI therapy, the aqueous flare value showed a significant decrease compared with before treatment (baseline). Significant correlations were noted between the aqueous flare value and the aqueous humor levels of 6 factors/cytokines, including sVEGFR-1, placental growth factor, monocyte chemoattractant protein 1, soluble intercellular adhesion molecule-1, interleukin (IL)-6, and interferon-inducible 10-kDa protein (IP-10). There was also a significant correlation between the change in aqueous flare value and improvement in CMT 1 month after IRI. Conclusions: These findings suggest that IRI reduces subclinical inflammation and that the aqueous flare value is influenced by inflammatory factors/cytokines. In addition, the change in the aqueous flare value may be an indicator of the response of CMT to IRI in patients with DME.