Abstract:AIM: To evaluate and compare the efficacy and safety of two treat-and-extend (T&E) regimens (2- and 4-week intervals, Δ2w and Δ4w) of intravitreal conbercept injections in patients with neovascular age-related macular degeneration (nAMD). METHODS: This 24-month prospective randomized controlled trial at the First Affiliated Hospital of Chongqing Medical University included patients with nAMD. Eyes were randomly assigned (1:1) to receive intravitreal conbercept (0.5 mg) with T&E regimens using 2- or 4-week interval adjustments (Δ2w and Δ4w groups). Key outcomes included best-corrected visual acuity (BCVA), central retinal thickness (CRT), subfoveal choroidal thickness (SFCT), superficial vascular density (SVD), deep vascular density (DVD), and large-medium vascular density (LMVD) within the 3 mm macular foveal region. The primary endpoint was the mean change in BCVA from baseline to the 2-year follow-up (noninferiority cutoff: 4 letters). RESULTS: Ultimately, 61 participants (68 eyes) completed the 2-year study. Baseline characteristics were similar between the two groups. At week 96, the mean number of injections was 11.17±1.13 in the Δ2w group (36 eyes, with the mean age of 70.42±9.31y) and 9.84±1.02 in the Δ4w group (32 eyes, with the mean age of 71.25±9.99y; P<0.001). The mean changes in BCVA were 5.19±6.58 and 5.91±5.51 letters (P=0.528), and Δ4w being noninferior to Δ2w (difference: 0.71 letters; 95%CI: -3.67 to 2.24). The mean changes in CRT were -118.97±106.97 and -134.98±128.77 μm (P=0.406), and the mean changes in SFCT were -30.03±17.48 and -32.55±22.73 μm (P=0.538), respectively. No significant intergroup differences in vascular densities were observed. Type 1 macular neovascularization had a higher baseline BCVA and required more injections than those with other macular neovascularization subtypes. CONCLUSION: Intravitreal conbercept injections administered via 2- and 4-week intervals show similar efficacy and safety. The reduced injection frequency in the Δ4w regimen may help lower the overall treatment burden, and individualized therapy based on nAMD subtypes may further optimize clinical outcomes.
