Serum concentration of vascular endothelial growth factor after bilateral intravitreal injection of bevacizumab

This study compared serum vascular endothelial growth factor (VEGF) concentration between patients given the bilateral and unilateral intravitreal injections of bevacizumab. In a prospective manner, serum VEGF levels in treatment-naive patients with age-related macular degeneration who underwent bilateral or unilateral intravitreal injections of bevacizumab were investigated. After informed consent, peripheral blood was collected from in patients who underwent bilateral or unilateral intravitreal injection of bevacizumab before and 1 month after the injection. Serum VEGF levels were measured by enzyme-linked immunosorbent assay after centrifugation. In addition, best-corrected visual acuity (BCVA) and central retinal thickness (CRT) before and 1 month after the injection were compared between each group. Twenty patients received bilateral injections (40 eyes) and 20 patients received unilateral injections. The VEGF concentrations (pg/mL) before the bilateral injection were 235.75 ± 183.16 and 252.53 ± 233.52 for the unilateral injection. They were significantly reduced to 153.88 ± 113.26 and 189.42 ± 251.72 after 1 month, respectively (p = 0.037 and 0.019), which are showing no significant difference between the two groups (p = 0.771). And there were no significant intergroup difference in pre- and postoperative BCVA and CRT. The bilateral simultaneous intravitreal injection of bevacizumab did not differ greatly from unilateral intravitreal injection in the influence on serum VEGF levels and the therapeutic outcome.