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    In this multicenter study, investigators evaluated the performance and safety of the Xen 45 ab interno gelatin stent (Allergan) for refractory glaucoma through a 12-month follow-up period.

    Study design

    The single-arm, open-label clinical trial enrolled 65 patients who experienced a failed filtering or cilioablative procedure (84.6%), or uncontrolled IOP (20–35 mm Hg) on maximum medical treatment (15.4%). They were followed for 12 months after stent implantation.


    Approximately 76% of the patients had IOP reductions of at least 20% compared with baseline, on the same or fewer medications. The average drop in IOP was 6.4 mm Hg, and patients were on 2 fewer IOP-lowering medications than they were at baseline. Almost 40% of patients did not require IOP lowering medications following stent placement.

    No intraoperative or unexpected postoperative complications were reported. Additional surgical intervention was required in 13.8% of patients due to uncontrolled IOP. About 15% of patients lost an average of 2 lines of vision, which self-resolved in 81% of this subgroup. Other postop complications included transient hypotony (24.6%) and IOP increase of greater than 10 mm Hg (21.5 %).


    The high percentage of patients who required at least 1 bleb needling (32.3%) may stem from conjunctival dissection prior to sponge application of MMC. The authors were unable to use a subconjunctival MMC injection as it is not FDA approved. There were no comparative arms for the intervention.

    Clinical significance

    The Xen can be used in refractory glaucoma in the face of failed prior surgery with good results and low complication rates at 12 months. Unlike the iStent or Cypass, it can also be used without cataract surgery.