Comparative efficacy of subretinal and intravitreal conbercept injections in polypoidal choroidal vasculopathy

To compare the clinical efficacy of subretinal versus intravitreal conbercept injections in the treatment of polypoidal choroidal vasculopathy (PCV).

In this retrospective, single-center study, 102 consecutive PCV patients treated between July 2022 and October 2023 were divided into two groups based on the injection regimen: subretinal injections (n = 55, 1 + PRN regimen) and intravitreal injections (n = 47, 3 + PRN regimen) of conbercept. Comprehensive assessments-including best-corrected visual acuity (BCVA), optical coherence tomography (OCT), and indocyanine green angiography (ICGA)-were performed at baseline and at 1, 2, 3, 6, 9, and 12 months. Outcome measures included changes in BCVA, macular retinal thickness (MRT), subfoveal choroidal thickness (SFCT), pigment epithelial detachment (PED) height, number of injections, and polyp regression rates.

Baseline characteristics were comparable between the two groups (all P > 0.05). Over the 12-month follow-up, the subretinal injection group showed significantly greater improvement in BCVA (Month 12: 0.21 ± 0.23 logMAR vs. 0.49 ± 0.42 logMAR; P < 0.001). Additionally, reductions in MRT, SFCT, and PED height were significantly more pronounced in the subretinal group compared with the intravitreal group (all P < 0.001). The subretinal group also required fewer injections (1.82 ± 0.94 vs. 3.85 ± 2.11; P < 0.001) and achieved a significantly higher rate of polyp regression (69.1% vs. 42.6%; P = 0.007). No significant ocular or systemic complications were reported in either group.

Subretinal conbercept provides superior and more durable anatomical and functional outcomes compared to intravitreal injection in patients with PCV. It also reduces treatment burden and enhances lesion regression, supporting its potential as a promising alternative therapeutic approach.