Association Between Aqueous Humor Vascular Endothelial Growth Factor Levels And Clinical Outcomes In Polypoidal Choroidal Vasculopathy After Intravitreal Aflibercept Injection

Objective: To study the changes of aqueous humor vascular endothelial growth factor(VEGF)levels before and after intravitreal aflibercept injection(IAI)in patients with polypoidal choroidal vasculopathy(PCV),and to analyze the association between VEGF and clinical outcomes.Methods: 17 patients with PCV(PCV group)and 10 cataract patients with normal fundus(control group)were included in this prospective study.Patients in the PCV group were treated with IAI monthly.Aqueous humor samples(0.05 ~ 0.1 ml)of the two groups were collected before surgical procedures.Patients of the PCV group underwent a comprehensive ophthalmologic examination,including slit lamp microscope,intraocular pressure,best corrected visual acuity(BCVA),color fundus photography and optical coherence tomography(OCT)to evaluate the clinical outcomes.Human VEGF Enzyme Linked-Immuno-Sorbent Assay(ELISA)Kit was used to detect the VEGF concentration in aqueous humor.Then,we evaluated the changes of aqueous humor VEGF levels and their associations with the clinical outcomes.Results: Patients in PCV group received IAI treatment 4.39 times on average,and none of the patients in this study had any systemic or ocular adverse events.After treatment,their BCVA increased from 0.6 to 0.4(Log MAR);the rate of resolution of serous or hemorrhagic pigment epithelium detachment(PED)was 13%;the rate of absorption of subretinal fluid was 70%;the rate of polyp regression was 43%.The average concentration of VEGF was 239.14 ± 126.12 pg / ml in the PCV group before treatment,and 124.61 ± 9.10 pg / ml in the control group,with statistically significant(t = 2.506,P = 0.033).The concentrations of VEGF in the PCV group after 1-month and 2-month treatment were 119.18 ± 91.78 pg / ml and 99.64 ± 63.68 pg / ml,respectively.And the difference between them was statistically significant,respectively(Z =-3.883,P = 0.000;Z =-3.920,P = 0.000).The average BCVA in the PCV group before treatment,after 1-month and 2-month treatment were 0.59±0.50,0.42±0.48 and 0.37±0.59,respectively.And it significantly improved after 1-month treatment when comparing with those before treatment(Z =-3.182,P =0.001).While there was no significant improvement in BCVA between the results of 2-month treatment and 1-month treatment(Z =-1.552,P =0.121).The average central retinal / lesion thickness(CR / LT)in the PCV group before treatment,after 1-month and 2-month treatment were 357.20±211.10 um,281.75±230.10 um and 275.85±220.30 um,respectively,which showed significant decrease after the 1st injection compared with those before treatment(Z =-3.304,P = 0.001).While there was no significant improvement in CR / LT between the results of the 2nd injection and the 1st injection(Z =-1.552,P= 0.121).The results of correlation analysis revealed that there was an association between the changes of aqueous humor VEGF and the changes of BCVA(r = 0.541,P = 0.014).Conclusion: Three consecutive,monthly intravitreal injection of Aflibercept in patients with PCV can yield a durable VEGF inhibition,visual acuity improvement and CR / LT reduction.Significant improvement of visual acuity and reduction of CR / LT take place in the first month of IAI treatment.