Serum vascular endothelial growth factor, insulin-like growth factor-1 and aflibercept levels in retinopathy of prematurity

Purpose To evaluate the serum levels of vascular endothelial growth factor (VEGF) and insulin-like growth factor-1 (IGF-1) after intravitreal injection of aflibercept (IVA) and the transition of aflibercept into systemic circulation in infants with severe retinopathy of prematurity (ROP). Study design Prospective study. Methods This single-centered prospective cohort study included infants who received IVA for the treatment of type 1 ROP in zone I and posterior zone II. Blood samples were collected before IVA and at 1 day and 1, 2, 4, and 8 weeks after IVA. VEGF, IGF-1 and aflibercept levels were measured. Results Thirty eyes of 15 infants received IVA of 1 mg/0.025 mL. Serum VEGF levels decreased significantly at 1 day and 1, 2, 4, and 8 weeks after IVA compared with baseline (P < 0.05). Serum aflibercept levels decreased significantly 1, 2, 4, and 8 weeks after IVA compared with the level at 1 day after IVA (P < 0.05) and increased significantly at 1 day, 1, 2, and 4 weeks after IVA compared with the baseline level (P < 0.05). No significant difference was detected between serum IGF-1 levels any time in any infant (P > 0.05). Conclusion Serum VEGF levels are suppressed for at least 8 weeks, and aflibercept could be detected in the systemic circulation at 4 weeks after injection. Clinicians should be cautious about changes in systemic VEGF levels and passage of the agent into systemic circulation after IVA in infants.