Conbercept Injection in Treatment of Severe Proliferative Diabetic Retinopathy

Phase 4

Completed

Conditions: Proliferative Diabetic Retinopathy
Tractional Retinal Detachment

Brief Summary: To evaluate efficacy of different intravitreal Conbercept injection therapy in the treatment of severe proliferative diabetic retinopathy.

Detailed Description: 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.

Recruitment & Eligibility

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.

Arm && Interventions

Group	Intervention	Description
IVC Preoperative group	Conbercept	Conbercept injection before vitrectomy
IVC Postoperative group	Conbercept	Conbercept injection at the end of vitrectomy
IVC Pre- and Post-operative group	Conbercept	First conbercept injection before vitrectomy and second at the end of operation.

Primary Outcome Measures

Name	Time	Method
Best-corrected Visual Acuity	6 months
Duration of Surgery	during the operation time	To evaluate the influence of these three methods to the final duration of surgery. We carefully estimated the time of the vitrectomy from insertion to extraction of the 23-gauge three-port trocars.
Intraoperative Bleeding	Time between the insertion and extraction of three 23-gauge vitrectomy ports	The grading criteria for intraoperative bleeding: Grade 1, spontaneous cessation of minor bleeding or bleeding that stopped by transient elevation of perfusion pressure; Grade 2, moderate bleeding requiring endodiathermy or broad blood clots formed far away from the bleeding site; Grade 3, thick blood clots exceeding half of the posterior pole or affecting the operation field.

Secondary Outcome Measures

Name	Time	Method
Number of Participants With Neovascular Glaucoma (NVG)	follow up period, up to an average of 6 months after the operation
Recurrent Retinal Detachment	follow up period, up to an average of 6 months after the operation
Reabsorption Time of Blood	follow up period, up to an average of 6 months after the operation	To monitor the reabsorption time of preretinal blood.
Need for Reoperation	follow up period, up to an average of 6 months after the operation	due to recurrent retinal detachment or unclear vitreous hemorrhage
Postoperative Preretinal Blood	postoperatively, up to 1 week	The grading criteria for postoperative preretinal blood: Grade 1, isolated blood clots within 10 disk area but without covering the posterior pole; Grade 2, broad blood clots exceeding 10 disk area regardless of involvement of the posterior pole; Grade 3, broad blood clots exceeding 10 disk area as well as involving the posterior pole. Maximal extent of preretinal blood within 1 week postoperatively was used for grading the extent of hemorrhage.
Frequency of Intraoperative Electrocoagulation	during the operation time	The number of times electrocoagulation, which was used to stop bleeding, was carefully counted.
Recurrent Vitreous Hemorrhage	follow up period, up to an average of 6 months after the operation	Recurrent vitreous hemorrhage(VH) was referred to any new episode of VH occurring after one week postoperatively, dividing into early stage (≤ 4 weeks) and late stage (\> 4 weeks).