Analysis of target cytokines affecting OCTA changes following anti-VEGF treatment in PCV eyes

Objective

To explore the predictability cytokines in aqueous humor affecting optical coherence tomography angiography (OCTA) parameters after anti-vascular endothelial growth factor (VEGF) treatment in patients with polypoidal choroidal vasculopathy (PCV).

Methods

A cross-sectional study was carried out.Twenty eyes of 20 patients with PCV were included in Xuzhou First People’s Hospital from July 2017 to July 2020.All PCV eyes were treated by intravitreal injection of conbercept (IVC) following 3+ PRN regimen.One hundred μl of aqueous humor was collected before treatment and before the third injection, respectively.Thirteen kinds of cytokines in the aqueous humor were detected with Luminex bead-based multiplex array.The aqueous humor of 16 eyes of 16 cataract patients with age and gender matched were collected in the same way during phacoemulsification surgery as control.The values of center macular thickness (CMT), subretinal fluid height (SRFH), pigment epithelial detachment height (PEDH) and pigment epithelial detachment diameter (PEDD) of the eyes in the PCV group were examined with OCTA system.The target cytokines in aqueous humor affecting OCTA parameter change values (the difference between before and after treatment) was analyzed.This study protocol was approved by an Medical Ethic Committee of Xuzhou First People’s Hospital (No.xyyll[2020]27) and complied with Declaration of Helsinki.Written informed consent was obtained from each patient prior to any medical invention.

Results

The concentration of interleukin-8 (IL-8), Leptin, hepatocyte growth factor (HGF), fibroblast growth factor-2 (FGF-2), angiopoietin-2 (Ang-2), endothelin-1 and vascular endothelial growth factor-A (VEGF-A) were significantly higher in aqueous humor of the PCV group before treatment than those in the cataract group (all at P<0.05). After treatment, the concentration of VEGF-A in aqueous humor of the PCV group was significantly lower than that before treatment (P<0.001). The values of CMT, SRFH, PEDH and PEDD were significantly reduced in comparison with before treatment, showing statistical significances (all at P<0.05). The concentration of VEGF-A in aqueous humor was positively correlated and endothelin-1 in aqueous humor was negatively correlated with the change value of CMT (r=0.592, -0.485, both at P<0.05). The concentration of IL-8 and HGF were positively correlated with SRFH change value (r=0.492, 0.466, both at P<0.05). VEGF-A and IL-8 concentraions of aqueous humor before treatment were the risk factor of the change value of CMT and SRFH.Every 1pg/ml increase of baseline VEGF-A, the CMT change value reduced 0.836 μm (P=0.006), and every 1pg/ml increase of baseline IL-8, the SRFH change value reduced 12.522 μm (P=0.028).

Conclusions

The concentrations of VEGF-A and IL-8 in aqueous humor might predict the CMT and SRFH improvement in PCV eyes after anti-VEGF therapy.

Biological determination; Polypoidal choroidal vasculopathy; Vascular endothelial growth factor-A; Interleukin-8; Optical coherence tomography angiography; Center macular thickness; Subretinal fluid height