Conbercept Injection in Treatment of Severe Proliferative Diabetic Retinopathy

To assess the clinical effects of preoperative, intraoperative or preoperative combined with intraoperative intravitreal conbercept (IVC) injection in pars plana vitrectomy (PPV) with silicone oil tamponade for severe proliferative diabetic retinopathy (PDR). Methods. These patients were randomly assigned to three groups: Group 1 received an IVC injection 3 to 5 days before surgery; Group 2 received an IVC injection at the end of surgery; and Group 3 received an IVC injection 3 to 5 days before PPV as well as an IVC injection at the end of PPV. Follow-up examinations were performed for at least six months after surgery.

Inclusion criteria

• Subjects of either sex aged ≥ 18 years.
• Diagnosis of diabetes mellitus (type 1 or type 2);
• Active proliferative diabetic retinopathy was clinically evident;
• Study eyes required a vitrectomy and silicone oil tamponade due to vitreous hemorrhage with significant fibrous proliferation, tractional retinal detachment in the posterior pole or complicated retinal detachment, which can be detected by B-scan ultrasonography.
• Ability to give informed consent.

Exclusion criteria

• Coexistent ocular disease that may interfere with visual outcome;
• Prior vitreoretinal surgery or anti-vascular endothelial growth factor (VEGF) pharmacotherapy in either eye;
• A macula-involving retinal detachment for >6 months in the study eye;
• Iris or angle neovascularization and neovascular glaucoma;
• known allergy to any components of conbercept formulation
• severe external ocular infection;
• pregnancy or current oral contraceptive intake;
• usage of anticoagulant or antiplatelet therapy;
• preoperative or postoperative poor diabetes control [serum hemoglobin A1c (HbA1c) >11.0%];
• uncontrolled systemic diseases, such as hypertension, cardiac diseases or presenting abnormal coagulation-associated blood diseases;
• <6 months of follow-up post initial surgery.