Short-term effect of intravitreal ranibizumab on intraocular concentrations of vascular endothelial growth factor-A and pigment epithelium-derived factor in neovascular glaucoma.

BackgroundThis study aims to evaluate concentrations of pigment epithelium-derived factor (PEDF) and vascular endothelial growth factor (VEGF)-A in aqueous of patients with neovascular glaucoma prior to, and shortly after, an intravitreal ranibizumab injection. DesignInterventional comparative study. ParticipantsThe study included patients undergoing an intravitreal ranibizumab injection about one week before anti-glaucomatous surgery (study group) or who underwent routine cataract surgery (control group). MethodsAqueous and blood samples were collected at the occasions of intravitreal injections, anti-glaucomatous surgery or cataract surgery. They were analysed by enzyme-linked immunosorbent assay. Main Outcome MeasuresConcentrations of PEDF and VEGF-A in aqueous. ResultsAt baseline, concentrations VEGF-A (36982105pg/mL vs. 233 +/- 98pg/mL) and PEDF (18.9 +/- 11.9ug/mL vs. 2.2 +/- 0.6ug/mL) were higher (P<0.001) in the study group (n=20 patients) than control group (n=20 patients). The VEGF-A/PEDF concentration ratio was higher in the study group (396 +/- 554 vs. 110 +/- 49; P=0.02). One week after the ranibizumab injection, iris neovascularization had completely regressed in 17 (85%) eyes, and VEGF-A concentration decreased significantly (P<0.001) to 184 +/- 130pg/mL. The PEDF concentration remained unchanged (19 +/- 12ug/mL). The VEGF-A/PEDF concentration ratio decreased to 13.2 +/- 13.6. Plasma concentrations of VEGF-A and PEDF did not differ significantly between both groups (P=0.65 and P=0.15, respectively) nor were they significantly correlated with the aqueous concentrations (all P>0.15). ConclusionsAqueous concentrations of VEGF-A and PEDF were significantly elevated in eyes with neovascular glaucoma. Within one week after intravitreal injection of ranibizumab, VEGF-A concentration decreased to subnormal levels, while the PEDF concentration remained unchanged and the VEGF-A/PEDF ratio decreased.