Cytokines and Recurrence of Macular Edema after Intravitreal Ranibizumab in Patients with Branch Retinal Vein Occlusion

The aqueous humor levels of cytokines and growth/inflammatory factors were measured in 46 branch retinal vein occlusion (BRVO) patients with macular edema (ME) who were treated with intravitreal ranibizumab injection (IRI). Patients with recurrence of ME received further IRI as needed. The number of IRIs was significantly correlated with age, baseline best-corrected visual acuity, and baseline central macular thickness (CMT), as well as the baseline aqueous levels of 5 cytokines/factors (soluble vascular endothelial growth factor receptor-1, platelet-derived growth factor-AA [PDGF-AA], soluble intercellular adhesion molecule-1, interleukin-6 [IL-6], and IL-8). Multivariate linear regression analysis with stepwise selection confirmed that age, baseline CMT, and baseline PDGF-AA level were independent determinants of the number of IRIs. These findings suggest that inflammatory factors may influence the recurrence of ME in BRVO patients, and that PDGF-AA might be a useful indicator of the number of IRIs required to control ME.