Real-world effect of vitrectomy combined with intravitreal conbercept for treatment of vitreous haemorrhage in proliferative diabetic retinopathy (QILIN I): a prospective cohort study

AIMS: To evaluate the efficacy of intravitreal conbercept (IVC) combined with pars-plana vitrectomy (PPV) for severe, non-clearing vitreous haemorrhage (VH) caused by proliferative diabetic retinopathy (PDR) in real-world practice. METHODS: This prospective, observational, multicentre, cohort study enrolled 523 patients with VH due to PDR at 26 hospitals from August 2022 to June 2024. Patients were treated with preoperative IVC (3-7 days prior to PPV), intraoperative IVC (at completion of PPV) and PPV alone as control. The primary outcome was the incidence of early (7-30 days) postoperative VH (POVH). Secondary outcomes included late POVH (30-180 days), postoperative best-corrected visual acuity (BCVA) and distribution of POVH severity. RESULTS: Of 425 participants (425 eyes) finally enrolled, 406 completed 30-day-visit, and 341 completed 180-day-visit. The incidence of early POVH was 24.0% (36 of 150) in preoperative IVC versus 23.2% (33 of 142) intraoperative IVC compared with 37.6% (50 of 133) in control (p=0.0160, 0.0122). The incidence of late POVH was 11.9% (16 of 134) in preoperative IVC versus 17.5% (20 of 114) intraoperative IVC versus 17.8% (19 of 107) in control (p=0.4109, 0.4661). The early POVH was less severe in preoperative and intraoperative IVC cohorts compared with control (p=0.0067, 0.0304), while the severity of late POVH was comparable (p=0.4860, 0.8353). Mean postoperative BCVA was all improved but showed no significant intergroup differences (p>0.05). CONCLUSIONS: This study, with the largest participants to date, demonstrates that IVC administered preoperatively or intraoperatively effectively reduces early POVH incidence, rather than late POVH. Preoperative IVC may be preferable for patients with more severe baseline disease characteristics.