Evaluation of the First-Dose Anti-VEGF Anatomical Response in Polypoidal Choroidal Vasculopathy Patients: Correlation with the Third-Dose Response and Risk Factor Analysis

Abstract

Introduction: To investigate whether first-dose efficacy can predict third-dose anatomical response and analyze the risk factors for first-dose response of polypoidal choroidal vasculopathy (PCV) patients. Methods: We retrospectively reviewed patients’ medical records from 27-centers of China PCV Research Alliance. PCV patients treated with intravitreal injections of Conbercept based on the 3+ pro re nata (PRN) regimen (three initial monthly injections, followed by injections as needed) with complete 3-month injection data were included. Response correlations, risk factor associations, changes in central macular thickness (CMT) or best-corrected visual acuity (BCVA), and number of injections in the first year of follow-up were evaluated separately in the pachy-PCV and non-pachy-PCV phenotypes. Results: 165 eligible patients were included. There was a significant correlation between first-dose and third-dose anatomical response in pachy-PCV or non-pachy-PCV patients (rs=0.611, p<0.001; rs=0.638, p<0.001). Multivariate analysis revealed associations of good first-dose anatomical response in pachy-PCV patients with baseline CMT with a predicted area under the curve (AUC) of 0.847, while a good response in non-pachy-PCV patients was associated with baseline BCVA, baseline CMT, pigment epithelial detachment (PED) height, higher proportion of intraretinal fluid (IRF), and lower PED minimum diameter with a predicted AUC of 0.940. CMT in the good first-dose response group was significantly decreased from baseline at all first-year follow-up visits in both groups (p<0.001), and mean BCVA was improved in the good vs. poor first-dose anatomical response group (5.4 vs. 1.6 ETDRS letters in pachy-PCV, 10.6 vs. 7.4 letters in non-pachy-PCV) after the third injection. No significant difference was observed in the number of injections in the first year of follow-up between different response groups. Conclusion: In PCV patients receiving IVC, the first- and third-dose response are significantly correlated, and different factors influence the first-dose response in different subtypes of PCV.