Comparison of the Efficacy and Safety of Conbercept Plus Panretinal Photocoagulation Versus Panretinal Photocoagulation Alone for Proliferative Diabetic Retinopathy: A Multicenter, Prospective, Randomized Controlled Study

This study compared the efficacy and safety of intravitreal injection of conbercept with panretinal photocoagulation (PRP) and PRP alone in Chinese patients with proliferative diabetic retinopathy (PDR) without center-involved diabetic macular edema (CI-DME). This multicenter, prospective, controlled study randomized patients with PDR without CI-DME (1:1) to receive a single conbercept intravitreal injection followed by PRP (combination group, n = 51) or PRP alone (PRP group, n = 59). Mild pre-retinal or vitreous hemorrhage was permitted but not required for enrollment. The primary outcome was the PRP completion rate at week 4. Secondary outcomes included the total number of PRP spots at week 4; best-corrected visual acuity (BCVA) and central subfield thickness (CST) changes from baseline to week 4, 12, 16, and 24; and treatment-related adverse events. Ninety-eight patients (89.1%) completed the study. Baseline demographics, ocular characteristics, and the presence of pre-retinal or vitreous hemorrhage were similar between the groups (all P > 0.05). The PRP completion rate at week 4 was 93.0% in the combination group, versus 76.4% in the PRP group ( P = 0.03). Reasons for PRP incompletion included vitreous hemorrhage (VH) progression (4.7% vs. 18.2%, P = 0.04) and pars plana vitrectomy (PPV) because of severe VH (2.3% vs. 5.5%, P = 0.79). The combination group demonstrated a smaller number of total PRP spots than the PRP group at week 4 (1380.1 ± 137.9 vs. 1558.8 ± 264.7, P < 0.01). The combination group displayed a BCVA improvement (expressed as the logarithm of the minimum angle of resolution) of 0.06 ± 0.10 at 4 weeks, whereas the PRP group exhibited a deterioration of 0.03 ± 0.08 ( P < 0.01). Similarly, for CST, the combination group displayed a reduction of 27.4 ± 27.5 μm at 4 weeks, versus an increase of 14.1 ± 27.2 μm in the PRP group ( P < 0.01). However, the changes in BCVA and CST from baseline were not significantly different between the groups at 12, 16, and 24 weeks. No serious adverse effects were reported in either group. Conbercept administered intravitreally 1 week prior to PRP helped improve the PRP completion rate and delayed VH progression. Its impact on long-term prognosis remains to be elucidated by future research. A prospective randomized controlled trial to compare the efficacy and safety of intravitreal injection of conbercept plus PRP versus PRP alone in Chinese patients with PDR without CI-DME (ChiCTR2200063637).