Purpose: To investigate the changes in plasma concentrations of vascular endothelial growth factor (VEGF), insulin growth factor (IGF-1), erythropoietin, pigment epithelium-derived factor, and IgG1 after bevacizumab intravitreal injection in infants with retinopathy of prematurity.
Methods: Eleven eyes from six infants who received intravitreal injection of bevacizumab were enrolled in this study. At preinjection and postinjection 1, 2, 3, 4, 5, 6, 7, and 8 weeks, 0.5 mL of blood was collected from each infant. The plasma concentrations of VEGF, insulin growth factor, erythropoietin, pigment epithelium-derived factor, and IgG1 were measured by enzyme-linked immunosorbent assay. Five patients received simultaneous bilateral bevacizumab injection; one patient received unilateral injection.
Results: Of the infants who received intravitreal bevacizumab injection, two were males and four were females. The mean gestational age was 26 ± 2 weeks. The mean birth weight was 870 g. The mean plasma VEGF concentration before bevacizumab injection was 2.05 ± 3.00 ng/mL; plasma level decreased significantly to 0.16 ± 0.10 ng/mL and to 0.14 ± 0.14 ng/mL (P = 0.028) after 1 week and 2 weeks, respectively. Moreover, the plasma concentrations of VEGF did not return to the original level in any of the samples until 8 weeks after the injection. However, mean plasma IgG1, erythropoietin, insulin growth factor, and PEDF concentrations did not change significantly during the interval between preinjection and any other follow-up time points.
Conclusion: Intravitreal bevacizumab injections significantly reduce plasma VEGF concentration in infants with retinopathy of prematurity over a 7-week period.