Effects of VEGF levels on anti-VEGF therapy for patients with idiopathic choroidal neovascularization

The objective of this study is to investigate the levels of vascular endothelial growth factor (VEGF) and other cytokines in aqueous humor of patients with idiopathic choroidal neovascularization (CNV) and their effects together with central retinal thickness (CRT) on the response to intravitreal injection of anti-VEGF antibody ranibizumab. This clinical study recruited 32 eyes from 32 patients with CNV under or besides fovea. VEGF, interleukin (IL)-6, IL-8, and monocyte chemoattractant protein (MCP)-1 levels were detected in aqueous humor (0.1 ml) sampled during intravitreal injection. Aqueous humor controls were from nine cataract patients without any systemic disorders. The VEGF levels in aqueous humor were negatively related (r = −0.373, p = 0.035) to CRT, which was positively related (r = 0.743, p < 0.001) to the number of injections. The VEGF levels before treatment and during the third injection in four patients with three or more injections were 13.42 ± 8.50 and 5.75 ± 3.68 (p = 0.055), respectively. The average best corrected visual acuity (BCVA) before and 12 months after treatment were 57.03 ± 16.15 and 75.16 ± 11.78 (p < 0.001), and the average CRT before and 12 months after treatment were 352.09 ± 84.15 and 251.13 ± 63.96 (p < 0.001), respectively. The visual improvement was negatively related (r = −0.815, p < 0.001) to the visual baseline, and the vision 12 months after treatment was positively related (r = 0.581, p < 0.001) to that before treatment. No severe ocular or systemic complication appeared during treatment and follow-ups for all the patients. Intravitreal injection of anti-VEGF antibody ranibizumab is safe and effective for the treatment of idiopathic CNV through decreasing CRT. The patients with larger CRT baseline need more injections of ranibizumab.