Vascular endothelial growth factor plasma levels before and after treatment of retinopathy of prematurity with ranibizumab

Purpose To evaluate vascular endothelial growth factor (VEGF) plasma levels before and after intravitreal injection of ranibizumab in patients with retinopathy of prematurity (ROP). Methods Case series study. Eleven infants with type 1 pre-threshold ROP were treated with intravitreal ranibizumab 0.5 mg. Blood samples were collected before intravitreal injection of ranibizumab and 1 day, 1 week, 2 weeks, and 4 weeks after injection. Concentration of plasma VEGF was measured by enzyme-linked immunosorbent assays (ELISA). Results The mean +/- standard deviation of plasma VEGF concentration of the available samples before and 1 day, 1 week, 2 weeks, and 4 weeks after a total of 0.5 mg ranibizumab injection were 46.07 +/- 9.40 pg/ml (n=11), 10.59 +/- 7.32 pg/ml (n=5), 45.76 +/- 6.75 pg/ml (n=5), 62.44 +/- 15.51 pg/ml (n=5), and 56.82 +/- 12.78 pg/ml (n=4) respectively. A significant reduction was found in the plasma VEGF levels 1 day after intravitreal injection of ranibizumab (P=0.002). No significant differences were found between before and 1 week, 2 weeks, and 4 weeks after the injection. Conclusions Intravitreal ranibizumab reduced plasma VEGF levels 1 day after injection in infants with ROP. This effect disappeared 1 week after the injection. Intravitreal ranibizumab did not induce prolonged systemic VEGF suppression.