Intravitreal Bevacizumab and Cytokine Levels in Major and Macular Branch Retinal Vein Occlusion

Abstract

Purpose: My aim was to evaluate the effect of intravitreal bevacizumab and to determine the concentrations of inflammatory cytokines in patients with macular edema due to branch retinal vein occlusion (BRVO), according to the site of the occlusion. Methods: In a prospective interventional case series, 46 eyes of patients with macular edema due to major (n = 30) or macular BRVO (n = 16) were included. The patients were treated primarily with intravitreal bevacizumab (1.25 mg/0.05 ml) and completed 12 months of follow-up. Reinjections were performed if optical coherence tomography showed persistent or recurrent macular edema. Aqueous humor samples were collected at the time of initial intravitreal injection. Multiplex bead assays were used for the measurement of cytokines. Results: The visual acuity and central macular thickness were improved significantly in patients with major and macular BRVO at 12 months. During 12 months, the eyes with major BRVO received a mean of 3.8 intravitreal injections, whereas those with macular BRVO received a mean of 1.9 intravitreal injections (p = 0.009). Significantly increased concentrations of IL-6, IL-8 and MCP-1 were observed in the aqueous humor of BRVO patients compared with control samples. Higher concentrations of IL-6, VEGF, PDGF-AA and MCP-1 were measured in the aqueous humor of patients with major BRVO compared with macular BRVO at baseline (p < 0.05). Conclusion: Intravitreal bevacizumab was similarly effective for improving macular edema in patients with major and macular BRVO. However, macular BRVO required fewer injections and had lower cytokine levels in the aqueous humor than major BRVO.