Ozurdex (a slow-release dexamethasone implant) in proliferative vitreoretinopathy: study protocol for a randomised controlled trial.

BACKGROUND: Proliferative vitreoretinopathy (PVR) is the commonest cause of late anatomical failure in rhegmatogenous retinal detachment. Visual and anatomical outcomes remain poor despite advances in vitreoretinal surgical techniques with reported primary failure rates of up to nearly 50%. Numerous adjunctive medications have been evaluated in clinical trials with no agent gaining widespread acceptance and use.This study was designed to investigate the benefits of using a slow-release dexamethasone implant delivered intra-operatively in patients undergoing vitrectomy surgery for retinal detachment with established PVR. METHODS/DESIGN: For the study, 140 patients requiring vitrectomy surgery with silicone oil for retinal detachment with established PVR will be randomised to receive either standard treatment or study treatment in a 1:1 treatment allocation ratio. Both groups will receive the standard surgical treatment appropriate for their eye condition and routine peri-operative treatment and care, differing only in the addition of the supplementary adjunctive agent in the treatment group. The investigated primary outcome measure is stable retinal reattachment with removal of silicone oil without additional vitreoretinal surgical intervention at 6 months. DISCUSSION: This is the first randomised controlled clinical trial to investigate the use of an adjunctive slow-release dexamethasone implant in patients undergoing vitrectomy surgery for retinal detachments with proliferative vitreoretinopathy. TRIAL REGISTRATION: EudraCT No: 2011-004498-96.

Two-quadrant high-volume sub-Tenon's anaesthesia for vitrectomy: a randomised controlled trial.

BACKGROUND: Total volume using a standard single inferonasal injection for sub-Tenon's anaesthesia is limited by an increase in intraocular pressure (IOP) and commonly requires the operating surgeon to top-up the block intraoperatively. This study compares the efficacy and safety of a two-quadrant technique that allows the use of a higher volume of local anaesthetic. METHODS: 54 patients undergoing vitrectomy were randomised into two groups. The control group (n=27) received a standard 5 ml single inferonasal sub-Tenon injection of a 50:50 mixture of 2% lidocaine and 0.5% bupivacaine with 150 IU hyaluronidase. The study group (n=27) received a 5 ml inferonasal and 5 ml superotemporal injection of the same mixture (10 ml total). The primary outcome measure was the number of intraoperative top-ups required. Secondary outcome measures were intraoperative and postoperative pain scores, IOP, block onset time, ocular akinesia, eyelid akinesia and chemosis. RESULTS: 24 patients required a top-up in the control group. No patients required a top-up in the study group (p<0.001). IOP measurements were similar in both groups. Block onset was shorter, eyelid akinesia was improved and pain scores were also reduced in the study group intraoperatively and at 0-2 h, 4-6 h, 10-14 h and 20-24 h postoperatively. CONCLUSIONS: Two-quadrant sub-Tenon's anaesthesia using 10 ml of a 50:50 mixture of 2% lidocaine and 0.5% bupivacaine with 150 IU hyaluronidase seems to be more effective than a single-quadrant technique at reducing intraoperative and postoperative pain during vitrectomy.