Changes in systemic vascular endothelial growth factor levels after intravitreal injection of aflibercept in infants with retinopathy of prematurity

To investigate the levels of VEGF in the systemic circulation of patients with type 1 ROP who received intravitreal injections of 1 mg (0.025 mL) aflibercept (IVA) or 0.625 mg (0.025 mL) bevacizumab (IVB).

Patients who had type 1 ROP and received either IVA or IVB were enrolled in this prospective study. Serum and plasma samples were collected prior to and up to 12 weeks after IVB or IVA treatment. The serum and plasma VEGF levels were measured using enzyme-linked immunosorbent assays (ELISAs), and the platelet levels in the blood were also quantified. The serum and plasma levels of VEGF, as well as the ratio of VEGF to platelet count (VEGF/PLT) were measured prior to and up to 12 weeks after anti-VEGF treatment.

In total, 14 patients with type 1 ROP were enrolled in this study; five patients received IVA, and nine patients received IVB. Following either IVA or IVB treatment, all the eyes (100%) showed complete resolution of ROP-induced abnormal neovascularization and presented continued vascularization toward the peripheral retina. Compared to baseline, the serum VEGF levels were significantly reduced in the ROP patients up to 12 weeks after either IVA or IVB treatments (all P < 0.05). At 2, 4, and 8 weeks after intravitreal injection, the serum VEGF levels were more suppressed in the IVB group than in the IVA group (P = 0.039, P = 0.004, and P = 0.003, respectively). The serum VEGF/PLT ratio after IVA or IVB showed similar reductions and trends as the serum VEGF data. Changes in the plasma VEGF levels could not be properly assessed because some of the samples had VEGF levels below the detection limit of the ELISA.

Serum VEGF levels and the VEGF/PLT ratio in patients with type 1 ROP were suppressed for 3 months after treatment with either IVA or IVB, but the suppression of systemic VEGF was more pronounced in patients treated with IVB than those treated with IVA.