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

Objective: 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.