PLASMA CONCENTRATIONS OF VASCULAR ENDOTHELIAL GROWTH FACTOR IN RETINOPATHY OF PREMATURITY AFTER INTRAVITREAL BEVACIZUMAB INJECTION

In Brief 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. Intravitreal bevacizumab injection has an effect on decrease of plasma vascular endothelial growth factor during 7 weeks after the injection significantly. However, plasma concentration of other cytokines such as insulin growth factor, pigment epithelium–derived factor, and erythropoietin did not show significant changes in that period after the injection.