POSSIBLE MOLECULAR BASIS OF BEVACIZUMAB THERAPY FOR MACULAR EDEMA IN BRANCH RETINAL VEIN OCCLUSION

Purpose:To investigate changes in the aqueous humor levels of 11 factors/cytokines (including vascular endothelial growth factor [VEGF] receptors, growth factors, and inflammatory factors) after intravitreal injection of bevacizumab (IVB), as well as the relationship between changes of these factors and improvement of macular edema in patients with branch retinal vein occlusion and macular edema.Methods:In 29 patients with branch retinal vein occlusion who received IVB twice for macular edema at monthly intervals, aqueous humor samples were obtained during IVB. Levels of VEGF, soluble VEGF receptor (sVEGFR)-1, sVEGFR-2, placental growth factor, soluble intercellular adhesion molecule-1, monocyte chemotactic protein 1, platelet-derived growth factor-AA, and interleukin (IL)-6, IL-8, IL-12 (p70), and IL-13 were measured by the suspension array method. Foveal thickness was examined by optical coherence tomography before and 1 month after IVB, and the improvement of macular edema was evaluated by calculating the percent change of foveal thickness.Results:Aqueous humor levels of sVEGFR-1, VEGF, monocyte chemotactic protein 1, and IL-6 showed a significant decrease at 1 month after IVB compared with baseline (P = 0.013, P < 0.001, P = 0.047, and P = 0.019, respectively). There was a significant negative correlation between the change of sVEGFR-1 or platelet-derived growth factor-AA after IVB and the improvement of macular edema (P = 0.004 and P = 0.036, respectively).Conclusion:These findings suggest that improvement of macular edema by IVB is related to inhibition of sVEGFR-1 and platelet-derived growth factor-AA, but not VEGF, in patients with branch retinal vein occlusion. Soluble VEGF receptor-1 and platelet-derived growth factor-AA might be useful indicators of the response of macular edema.