Intraocular and systemic levels of vascular endothelial growth factor in advanced cases of retinopathy of prematurity

Raul Velez-Montoya¹, Carmen Clapp², Jose Carlos Rivera², Gerardo Garcia-Aguirre¹, Virgilio Morales-Cantón¹, Jans Fromow-Guerra¹, Jose Luis Guerrero-Naranjo¹, Hugo Quiroz-Mercado<sup>3

1</sup>Retina Department Asociación para Evitar la Ceguera en México IAP, México City, México; ²Department of Cellular and Molecular Neurobiology, Universidad Nacional Autónoma de México, Querétaro, México; ³Department of Ophthalmology, Denver Health Medical Center, University of Colorado School of Medicine, Colorado, USA

Purpose: To measure vitreous, aqueous, subretinal fluid and plasma levels of vascular ­endothelial growth factor in late stages of retinopathy of prematurity.

Methods: Interventional study. We enrolled patients with clinical diagnoses of bilateral stage V retinopathy of prematurity, confirmed by b-scan ultrasound and programmed for vitrectomy. During surgery we took samples from blood, aqueous, vitreous, and subretinal fluids. The vascular endothelial growth factor concentration in each sample was measured by ELISA reaction. A control sample of aqueous, vitreous and blood was taken from patients with congenital cataract programmed for phacoemulsification. For statistical analysis, a Mann–Whitney and a Wilcoxon W test was done with a significant P value of 0.05.

Results: We took samples of 16 consecutive patients who met the inclusion criteria. The vascular endothelial growth factor levels in the study group were: aqueous, 76.81 ± 61.89 pg/mL; vitreous, 118.53 ± 65.87 pg/mL; subretinal fluid, 1636.58 ± 356.47 pg/mL; and plasma, 74.64 ± 43.94 pg/mL. There was a statistical difference between the study and the control group (P < 0.001) in the aqueous and vitreous samples.

Conclusion: Stage 5 retinopathy of prematurity has elevated intraocular levels of vascular endothelial growth factor, which remains high despite severe retinal lesion. There was no ­statistical difference in plasma levels of the molecule between the control and study group.

Keywords: VEGF, late stages, ROP