Original Article Serum Concentration of Vascular Endothelial Growth Factor after Bilateral Intravitreal Injection of Bevacizumab

Purpose: This study compared serum vascular endothelial growth factor (VEGF) concentration between pa-tients given the bilateral and unilateral intravitreal injections of bevacizumab. Methods: In a prospective manner, serum VEGF levels in treatment-naive patients with age-related macular de-generation 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 intrav-itreal 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. Results: 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. Conclusions: The bilateral simultaneous intravitreal injection of bevacizumab did not differ greatly from unilater-al intravitreal injection in the influence on serum VEGF levels and the therapeutic outcome