Efficacy and Safety of the Ab-interno Xen Gel Stent After Failed Trabeculectomy.

Abstract

AIMS: To assess the efficacy and safety of the Xen gel stent in reducing intraocular pressure (IOP) in eyes with prior failed trabeculectomy and to determine the frequency of complications and further intervention. METHODS: Retrospective case note review of all patients with prior trabeculectomy undergoing Xen surgery across 5 centers from August 2015 to May 2017. RESULTS: In total, 17 surgeries were reviewed. IOP reduced from 21.5 (±2.4) mm Hg preoperatively to 13.6 (±3.4) mm Hg at month 12 (P<0.05). Medication usage reduced from 2.8 (±0.6) preoperatively to 1.0 (±1.3) at month 12 (P<0.05). Adverse events included: numerical hypotony (IOP<6 mm Hg) in 4 cases (23.5%) that all resolved spontaneously, IOP spike of ≥30 mm Hg in 2 (11.8%) cases and transient occlusion of the implant by iris in 1 (5.9%) case. Secondary filtration surgery (Baerveldt tube implantation) was required in 2 (11.8%) cases. Postoperative bleb intervention was required in 9 cases (52.9%), usually in the first month after surgery. CONCLUSIONS: Xen reduces IOP and number of medications in eyes with failed trabeculectomy. Detailed preoperative conjunctival assessment and targeted stent placement is required. Prospective data and follow-up beyond 12 months are required but Xen seems a viable, effective, and safe option after failed trabeculectomy.