Concentration of Vascular Endothelial Growth Factor in Aqueous Humor of Eyes With Advanced Retinopathy of Prematurity Before and After Intravitreal Injection of Bevacizumab

In Brief Purpose: To determine whether an intravitreal injection of bevacizumab alters the concentration of vascular endothelial growth factor (VEGF) in the aqueous humor of eyes with retinopathy of prematurity. Methods: Seven Stage 4 and three Stage 5 eyes of eight patients with retinopathy of prematurity were studied. Bevacizumab (0.75 mg/0.03 mL/eye) was injected intravitreally in six eyes of six patients after approval was obtained from the Institutional Review Board of Nagoya University Hospital and an informed consent was signed by the parents. Aqueous humor was collected just before the surgery or before the intravitreal injection of bevacizumab. Aqueous humor was also collected immediately before vitrectomy 4 to 48 days after the injection of bevacizumab. Aqueous humor was also collected from four patients undergoing congenital cataract surgery as controls. The concentration of VEGF was measured by enzyme-linked immunosorbent assay. Results: In the 4 control eyes, the concentration of VEGF in 2 eyes was 156 and 158 pg/mL and was not detectable in the other 2 eyes. The average concentration of VEGF was 1,109 pg/mL in the active Stage 4 eyes and 3,520 pg/mL in the active Stage 5 eyes. After bevacizumab injection, the unbound VEGF concentration was 60, 230, and 290 pg/mL in 3 eyes and not detectable in 1 eye. Conclusion: Intravitreal bevacizumab resulted in a marked decrease in the unbound VEGF concentration in eyes with retinopathy of prematurity. The VEGF concentration with or without bevacizumab injection was studied in Stage 4 and 5 ROP eyes. The average concentration was 1109 pg/ml in the active Stage 4 eyes, and 3520 pg/ml in the active Stage 5 eyes. After bevacizumab, the unbound VEGF concentration was <300 pg/ml in all eyes.