The Vitrectomy Plus Encircling Band Vs. Vitrectomy Alone For The Treatment Of Pseudophakic Retinal Detachment (VIPER) trial is underway to evaluate the effectiveness of different surgical techniques for treating pseudophakic retinal detachment (PRD). This multi-center, three-arm, randomized clinical trial compares the outcomes of 20G vitrectomy alone versus 20G vitrectomy with an encircling band, and explores the non-inferiority of 23/25G vitrectomy compared to 20G vitrectomy alone.
Study Design and Objectives
The VIPER trial aims to determine if adding an encircling band to a standard 20G vitrectomy improves outcomes for patients with PRD. The primary objective is to assess the superiority of combining vitrectomy with an encircling band (E1) compared to vitrectomy alone (C) in preventing the need for additional retinal re-attachment surgeries. A secondary, exploratory objective is to investigate whether 23/25G transconjunctival vitrectomy (E2) is non-inferior to 20G vitrectomy (C) when performed without an encircling band.
The primary endpoint is defined as the absence of any situation requiring an additional retina re-attaching procedure within 26 weeks post-surgery. These procedures include additional gas injection, vitrectomy, or scleral buckling. Secondary endpoints include assessments of efficacy and safety, with a clinical endpoint committee evaluating documented clinical data to determine the incidence of key study events.
Methodology
The trial enrolled pseudophakic patients over 18 years of age with rhegmatogenous retinal detachment across 14 specialized retinal surgery centers. Key exclusion criteria included manifest uveitis, uncontrolled glaucoma, active retinal vascular disease, intraocular tumors, prior intraocular surgery (excluding cataract surgery), giant retinal tears, proliferative vitreoretinopathy, aphakia, and systemic disorders preventing anesthesia or participation in follow-up examinations.
Patients were randomized to one of three groups:
- Control Group (C): 20G vitrectomy without encircling band.
- Experimental Group 1 (E1): 20G vitrectomy with encircling band.
- Experimental Group 2 (E2): 23G or 25G vitrectomy without encircling band.
Surgeons participating in the trial were required to have extensive experience with vitrectomy procedures. The randomization was stratified by surgeon to ensure comparable intervention groups. Data collection and management were performed using a validated electronic database with central monitoring to ensure data quality.
Rationale and Background
Vitrectomy combined with scleral buckling has been a common approach for treating PRD. While some studies suggest enhanced support of the vitreous base and better visualization of the periphery with additional buckling procedures, others find no significant benefit. The VIPER trial seeks to provide robust, randomized evidence to clarify the role of encircling bands in vitrectomy for PRD.
Statistical Analysis
The primary analysis of E1 versus C will be based on the intention-to-treat (ITT) principle, with missing primary endpoints considered treatment failures. The comparison of E2 versus C will be exploratory, with both ITT and per-protocol (PP) analyses considered. A non-inferiority margin of 1.25 (OR) will be used for the E2 versus C comparison. Statistical methods include Cochran–Mantel–Haenszel tests and logistic regression, stratified by surgeon, with sensitivity analyses using multiple imputation methods.
Ethical Considerations
The study was designed and conducted according to Good Clinical Practice (GCP) principles and data protection laws. The protocol was registered prospectively in the German Clinical Trials Register (DRKS00003158).
