Efficacy and Safety Comparison of IVR and IVC Before Vitrectomy in Proliferative Diabetic Retinopathy

Study Overview
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Brief Summary
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Proliferative diabetic retinopathy (PDR) is the most common causes of irreversible blindness in diabetic retinopathy (DR).Although pars plana vitrectomy (PPV) is the cornerstone for treatment of advanced PDR, related postoperative complications such as recurrent VH, NVG, and postoperative fibrovascular proliferation progression may still cause serious visual impairment. Preoperative intravitreal injections of anti-VEGF drugs may represent a new strategy for making vitrectomy safer and more effective for severe PDR.

Detailed Description
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Proliferative diabetic retinopathy (PDR) is the most common causes of irreversible blindness in diabetic retinopathy (DR).It is characterized by progressive loss of vision, retinal edema, vitreous hemorrhage (VH), retinal neovascularization, fibrovascular proliferation, tractional retinal detachment (TRD) and neovascular glaucoma (NVG).Although pars plana vitrectomy (PPV) is the cornerstone for treatment of advanced PDR, related postoperative complications such as recurrent VH, NVG, and postoperative fibrovascular proliferation progression may still cause serious visual impairment. It is well known that vascular endothelial growth factor (VEGF) is a leading role of the neovascularization, vascular permeability, and diabetic macular edema.preoperative intravitreal injections of anti-VEGF drugs may represent a new strategy for making vitrectomy safer and more effective for severe PDR.Until now, there are two kinds of anti-VEGF drugs in China, including monoclonal antibodies, like imported drug Ranibizumab, militating by block VEGF-A, and fusion proteins, like domectic drug Conbercept, competitively inhibiting the binding of VEGF with its receptor by blocking multiple targets, VEGF-A, VEGF-B, and placental insulin-like growth factor (PlGF). Studies focusing on the comparison of efficacy between preoperative intravitreal injections of the two drugs for patients with severe PDR undergoing vitrectomy is still limited. Thus, in this study, we aim to carry out a more comprehensive comparison in intraoperative and postoperative aspects on the efficacy and safety between intravitreal ranibizumab injection (IVR) and intravitreal conbercept injection (IVC) before vitrectomy of PDR.

Official Title
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Efficacy and Safety Comparison of Ranibizumab and Conbercept Pretreatment Before Vitrectomy in Proliferative Diabetic Retinopathy

Conditions
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Proliferative Diabetic Retinopathy

Intervention / Treatment
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* Procedure: preoperative intravitreal injections of ranibizumab or conbercept


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients aged 18 years or more with type 1 or 2 diabetes who were clinically diagnosed with diabetic retinopathy (DR); hemoglobin A1c (HbA1c) ≤ 12%; persistent VH for more than 1 month or recurrent vitreous hemorrhage (VH) with or without panretinal photocoagulation (PRP); TRD detected by indirect ophthalmoscope or B-scan ultrasonography. Exclusion Criteria: previous vitreoretinal surgeries (including vitrectomy, intravitreal drug injection) in the study eyes; eyes with any ocular disease that may hinder visual improvement other than PDR, such as optic atrophy or macular hole; history of thromboembolic events (including cerebral vascular infarctions or myocardial infarctions) or coagulation system disorders or receiving anticoagulant or antiplatelet therapy; eyes given gas tamponade or additional treatment like ranibizumab injection again or supplementary retinal photocoagulation during follow-up periods.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: IVR group<br>Patients that received intravitreal ranibizumab injections (IVR) (0.5mg/0.05ml) before vitreous surgery were assigned to IVR group 3-5 days before three-port transconjunctival 25-G pars plana vitrectomy (PPV). All patients underwent 25-gauge transconjunctival sutureless vitrectomy using the 25-gauge Constellation system (Alcon, Fort Worth, TX, USA) system under local or anesthesia. A speed of 5000 cuts per minute was used for vitrectomy. | Procedure: preoperative intravitreal injections of ranibizumab or conbercept<br>* IVR group means patients received intravitreal ranibizumab injections (IVR) (0.5mg/0.05ml) before vitreous surgery. IVC group means patients that received intravitreal conbercept injection (IVC) (0.5mg/0.05ml) before vitreous surgery.<br>|
| Experimental: IVC group<br>Patients that received intravitreal conbercept injection (IVC) (0.5mg/0.05ml) before vitreous surgery were assigned to IVC group 3-5 days before three-port transconjunctival 25-G pars plana vitrectomy (PPV). All patients underwent 25-gauge transconjunctival sutureless vitrectomy using the 25-gauge Constellation system (Alcon, Fort Worth, TX, USA) system under local or anesthesia. A speed of 5000 cuts per minute was used for vitrectomy. | Procedure: preoperative intravitreal injections of ranibizumab or conbercept<br>* IVR group means patients received intravitreal ranibizumab injections (IVR) (0.5mg/0.05ml) before vitreous surgery. IVC group means patients that received intravitreal conbercept injection (IVC) (0.5mg/0.05ml) before vitreous surgery.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| BCVA | best-corrected visual acuity | from preoperation to 3 months follow-up | 
| CRT | central retinal thickness | from preoperation to 3 months follow-up | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| surgery time | surgery time | during surgery | 
| intraoperative bleeding | intraoperative bleeding | during surgery | 
| intraocular electrocoagulation use | intraocular electrocoagulation use | during surgery | 
| incidence of iatrogenic retinal breaks | incidence of iatrogenic retinal breaks | during surgery | 
| relaxing retinotomy | relaxing retinotomy | during surgery | 
| retinal reattachment | retinal reattachment | during surgery | 
| silicone oil tamponade | silicone oil tamponade | during surgery | 
| postoperative vitreous hemorrhage (VH) | postoperative vitreous hemorrhage (VH) | during 3 months follow-up | 
| neovascular glaucoma (NVG) | neovascular glaucoma (NVG) | during 3 months follow-up | 
| recurrent retinal detachment | recurrent retinal detachment | during 3 months follow-up | 
| postoperative fibrovascular proliferation progression | postoperative fibrovascular proliferation progression | during 3 months follow-up | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Proliferative diabetic retinopathy; ranibizumab; conbercept