Cryoapplication Versus Anti-VEGF Before Diabetic Vitrectomy

Study Overview
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Brief Summary
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Pars-plana vitrectomy (PPV) is the cornerstone of surgical treatment for eyes with complicated proliferative diabetic retinopathy. Anti-VEGF intravitreal injection before PPV has shown a good effect on surgical outcomes. However, many patients present with co-morbidities that contraindicate the usage of anti-VEGF in the pre-operative period. Thus, cryoapplication, an old therapeutic tool for proliferative diabetic retinopathy may be a good alternative. The investigators present herein a comparative study between peripheral retinal cryoapplication and anti-VEGF before vitrectomy for complicated proliferative diabetic retinopathy.

Detailed Description
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Pars-plana vitrectomy (PPV) is the cornerstone of surgical treatment of complicated proliferative diabetic retinopathy allowing the removal of vitreous opacity and releasing tractions from the retina. Surgical outcomes, however, are variable depending on a large array of pre, per, and post-operative conditions. The preoperative anti-VEGF intravitreal injection has shown a good effect on surgical outcomes in patients with vitreous hemorrhage or tractional retinal detachment. However, a great number of patients present with co-morbidities that contraindicate the usage of anti-VEGF in the pre-operative period. Thus, an alternative to this adjunctive therapy is worth investigating. In another hand, cryoapplication, an old therapeutic tool for proliferative diabetic retinopathy had been used in patients with non-clear ocular media with vitreous hemorrhage. The investigators present herein a comparative study between peripheral retinal cryoapplication and anti-VEGF before vitrectomy for complicated proliferative diabetic retinopathy.

Official Title
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Peripheral Retinal Cryoapplication Versus Anti-VEGF Intravitreal Injection Before Vitrectomy for Complicated Proliferative Diabetic Retinopathy

Conditions
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Proliferative Diabetic Retinopathy, Vitreous Hemorrhage, Tractional Retinal Detachment

Intervention / Treatment
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* Drug: Bevacizumab Injection [Avastin]
* Procedure: Peripheral Retinal Cryoapplication


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Type 1 or 2 diabetes mellitus Vitreous or retro-hyaloidal hemorrhage and/or tractional retinal detachment threatening or involving the macula No or less than 1000 impacts of preoperative retinal photocoagulation and/or iris rubeosis Only one eye per participant Exclusion Criteria: Negative light perception Previous vitrectomy Contraindication to anti-VEGF therapy or retinal cryoapplication Associated rhegmatogenous retinal detachment

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: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Preoperative Anti-VEGF Intravitreal Injection<br>Three to five days before vitrectomy, each participant received one intravitreal Bevacizumab injection (1.25 mg,0.05 ml). | Drug: Bevacizumab Injection [Avastin]<br>* Intravitreal injection of bevacizumab (1.25 mg, 0.05 ml) in the inferior temporal quadrant of the eye, 4 mm behind the limbus in phakic eyes, and 3.5 mm in pseudophakic eyes.<br>* Other names: IVB;|
| Experimental: Peripheral Retinal Cryoapplication<br>Four to six weeks before vitrectomy, each participant underwent peripheral retinal cryoapplication. | Procedure: Peripheral Retinal Cryoapplication<br>* In the operating room under peribulbar anesthesia, four focal conjunctival incisions are made on each quadrant between the muscles insertions. The Tenon capsule is opened with scissors to expose the sclera. Four to six cryo-applications are made per quadrant, at the edge of muscle insertion and a line behind. The exposure time is 4 to 5 seconds. 7-0 resorbable sutures are then put on each quadrant to close the conjunctiva.<br>* Other names: CRYO;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total surgical time | Duration of vitrectomy from the placement of the trocars until their removal | at the end of the vitrectomy | 
| Intraoperative bleeding | occurrence of intravitreal bleeding during vitrectomy | at the end of the vitrectomy | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postoperative bleeding | occurrence of intravitreal bleeding after vitrectomy | one month after the vitrectomy | 
| Visual acuity | Best corrected logMAR visual acuity | one month after the vitrectomy | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Retinal cryoapplication, Anti-VEGF, Vitrectomy