Comparative study of the efficacy of two intravitreal conbercept regimens in the treatment of polypoidal choroidal vasculopathy

To assess the efficacy and safety of the treat-and-extend (TAE) regimen and pro re nata (PRN) regimen of intravitreal conbercept in polypoidal choroidal vasculopathy (PCV) patients.

A non-randomized controlled study was performed.Ninety-one patients (91 eyes) diagnosed with treatment-naïve PCV from October 2016 to January 2019 at Department of Ophthalmology, Peking University People’s Hospital were enrolled.All the patients received the intravitreal injection of 0.5 mg conbercept.After the initial treatment, the patients were divided into 3+ PRN group and 3+ TAE group according to their willingness.The follow-up time was one year.All the eyes underwent visual acuity test with ETDRS chart, optical coherence tomography (OCT) examination, fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA). Best corrected visual acuity (BCVA), central retinal thickness (CRT), maximum retinal thickness (MRT), pigment epithelium detachment (PED) height, the number and area of polypoidal lesions, the area of retinal hemorrhage and the area of branching vascular network (BVN) were recorded.Treatment interval and injection frequencies during the one-year follow-up were compared between the two groups.This study adhered to the Declaration of Helsinki.The study protocol was approved by Peking University People’s Hospital (No.2020PHB250-01). Written informed consent was obtained from each patient.

One-year after treatment, the BCVA improvement in the 3+ PRN group and 3+ TAE group was 5.0(-2.0, 15.0) and 6.0(-1.0, 14.0) letters, respectively, showing no significant difference (Z=-0.352, P=0.725). No significant differences were found in CRT, MRT and PED height between the two groups (Z=-0.145, -0.529, -0.985, all at P>0.05). There was no significant difference in polypoidal lesions number, polypoidal lesions area, the number of eyes with different degrees of polyp regression, BVN area and retinal hemorrhage area between the two groups (Z=-0.502, -0.300, -0.047, -0.265, -1.243, all at P>0.05). After the one-year follow-up, the mean injection frequency of 3+ PRN group was (7.6±0.9) times, which was lower than (8.4±2.0) times of 3+ TAE group, showing a significant difference (t=2.432, P=0.019). The mean follow-up frequency was (11.3±1.5) times of 3+ PRN group, which was significantly higher than (10.1±1.7) times of 3+ TAE group (t=3.403, P=0.001). For the 3+ TAE group, 17.1%(6/35) of patients achieved an extension interval of 12 weeks after the first 3 doses, and 48.5%(17/35) of patients achieved an extension interval of 8 weeks or more, with a mean maximum extension interval of (9.5±2.0) weeks.During the follow-up, 10 patients in 3+ PRN group and 8 patients in 3+ TAE group received photodynamic therapy as a rescue treatment.

The 3+ PRN and 3+ TAE regimens of intravitreal injection of conbercept combined with photodynamic therapy as a rescue treatment have similar efficacy in visual and anatomical outcomes for PCV patients.3+ TAE regimen has a higher treatment frequency and fewer follow-up visits.