The lack of association between vascular endothelial growth factor and retinopathy of prematurity in an observational study.

OBJECTIVE

The objective of this study was to investigate the association between prematurity, vascular endothelial growth factor A (VEGF-A), VEGFR-1 (soluble fms-like tyrosine kinase-1 (sFLT-1)) and retinopathy of prematurity (ROP).

METHODS

A cohort of 53 neonates (gestation <28 weeks) was recruited into this study and peripheral venous samples for VEGF and sFLT-1 measurement were obtained between gestational ages 320-326 weeks.

RESULTS

The mean birth weight for the preterm neonates was 850 (178) g and the median gestational age was 26.4 [24.7-27.4] weeks. The median VEGF-A level was 1348 [608-2216] pg/mL and the median sFLT-1 level was 178 [103-244] pg/mL. Thirty-three neonates (33/53) developed various stages of ROP during their stay in the neonatal unit but only five neonates developed severe (stage 3) ROP needing treatment. The neonates with ROP were smaller (birth weight 801 (111) vs. 990 (175) g; p < .0001), more preterm (gestation 25.4 [24.2-26.0] vs. 27.1 [26.8-27.9] weeks; p < .0001) and received supplemental oxygen for a longer duration (1140 [218-1813] vs. 04 [40-434] hours; p= .012). There was no statistically significant difference in the VEGF-A level or sFLT-1 levels between those who developed ROP and those who did not. There was a positive correlation between VEGF and both birth weight and gestation, respectively. There was no correlation between sFLT1 and birth weight or gestation. VEGF-A/sFLT-1 ratio in babies treated for ROP was significantly lower compared to those not treated (2.8 [1.0-5.7] vs. 9.9 [5.6-13.7]; p = .04). A logistic regression model identified gestational age to be a statistically significant predictor of ROP (odds ratio 0.03 (0.001-0.550); p = .019).

CONCLUSIONS

There is no direct correlation between systemic VEGF-A or sFLT-1 plasma levels and severity of ROP in extremely preterm neonates. The link between VEGF and ROP remains to be fully understood.