A Study on the Treatment Strategy of NVG Secondary to PDR

Study Overview
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Brief Summary
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With the increasing incidence of proliferative diabetic retinopathy (PDR), subsequent neovascular glaucoma (NVG) has become one of the main causes of blindness in PDR patients, and the intraocular pressure of PDR patients with NVG is often stubborn. For these patients, not only is the effect of drugs in lowering intraocular pressure poor, but the results of surgery are often unsatisfactory. Because of its poor prognosis, clinical research for better strategy is of great significance in the current situation. At present, for such patients, a combination of effective control of intraocular pressure and treatment of the primary disease is often used. The purpose of this study was to investigate the clinical effects of preoperative with/without intraoperative anti-vascular endothelial growth factor (VEGF) drug therapy combined with pars plana vitrectomy (PPV), pan-retinal photocoagulation (PRP), and pressure-reducing valve implantation in patients with NVG secondary to PDR. Furthermore, the changes of neurotrophic factors in the vitreous humor before and after anti-VEGF treatment will be explored.

Official Title
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A Study on the Treatment Strategy of Neovascular Glaucoma Secondary to Proliferative Diabetic Retinopathy

Conditions
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Neovascular Glaucoma, Proliferative Diabetic Retinopathy

Intervention / Treatment
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* Drug: anti-VEGF


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: male or female patients aged over 18 years diagnosed with type 1 or 2 diabetic mellitus (DM) confirmed by experienced endocrinologists. Active PDR and NVG was clinically evident across these patients. The indications to perform surgery included vitreous hemorrhage or fibrous proliferation in the macular area, together with uncontrolled intraocular pressure. Exclusion Criteria: (i) coexistent ocular disease that may interfere with visual outcome; (ii) previous history of vitrectomy or anti-VEGF pharmacotherapy in either eye; (iii) a macula-involving retinal detachment for >6 months in the study eye; (iv) severe external ocular infection; (v) usage of anticoagulant or antiplatelet therapy; (vi) preoperative or postoperative poor diabetes control [serum hemoglobin A1c (HbA1c) >11.0%]; (vii) uncontrolled systemic diseases, such as hypertension, cardiac diseases or presenting abnormal coagulation-associated blood diseases.

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: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: pre-vitrectomy anti-VEGF injection group<br>Patient in this group receive an intravitreal injection of anti-VEGF drug 3-5 days before surgery, followed by PPV combined with PRP and pressure-reducing valve implantation | Drug: anti-VEGF<br>* To explore whether adding post-vitrectomy anti-VEGF agent injection can reach a better prognosis in PDR patients with NVG who underwent PPV combined with PRP and pressure-reducing valve implantation<br>|
| Experimental: pre and post-vitrectomy anti-VEGF injection group<br>Patient in this group receive two intravitreal injections of anti-VEGF drugs. One is injected 3-5 days before surgery, the other is at the same time as the PPV combined with PRP and pressure reducing valve implantation is completed. | Drug: anti-VEGF<br>* To explore whether adding post-vitrectomy anti-VEGF agent injection can reach a better prognosis in PDR patients with NVG who underwent PPV combined with PRP and pressure-reducing valve implantation<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in Best Corrected Visual Acuity from baseline to 12 months after surgery |  | Follow-up on the first day, first week, 1, 3, 6, 9 and 12 months after surgery | 
| Changes in Intraocular Pressure from baseline to 12 months after surgery |  | Follow-up on the first day, first week, 1, 3, 6, 9 and 12 months after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in Neovascularization Recurrence Rate from baseline to 12 months after surgery |  | Follow-up on the first day, first week, 1, 3, 6, 9 and 12 months after surgery | 
| Changes in Ocular and Systemic Adverse Events from baseline to 12 months after surgery |  | Follow-up on the first day, first week, 1, 3, 6, 9 and 12 months after surgery |