Interim Analysis of Clinical Outcomes with Open versus Closed Conjunctival Implantation of the XEN45 Gel Stent

Abstract

/Purpose: To examine the longitudinal postoperative outcomes of open versus closed conjunctiva implantation of the XEN45 gel stent. Retrospective multicenter study. 193 patients with glaucoma underwent XEN45 implantation via an open or closed conjunctiva approach. Patient demographics, diagnoses, preoperative and postoperative clinical data, outcome measures including intraocular pressure (IOP), use of glaucoma medications, visual acuity, and complications were collected. Statistical analyses were performed with P < 0.05 as significant. Failure was defined as less than 20% reduction of IOP from medicated baseline or IOP > 21 mmHg at 2 consecutive visits at postoperative month 1 and beyond, the need for subsequent operative intervention or additional glaucoma surgery, or a catastrophic event such as loss of light perception. Eyes that had not failed by these criteria and were not on glaucoma medications were considered complete successes. Overall success was defined as those who achieved success either with or without topical medications. Patients were followed for an average of 17 months. Complete success was achieved in 42.5% and 24.7% of the open and closed groups, respectively (P = 0.01). Overall success was achieved in 64.2% and 37.0% of the open and closed groups, respectively (P < 0.001) at the last follow up. Bleb needling was performed in 12.4% of eyes in the open group compared to 40% in the closed group. An IOP spike of 10 mmHg or greater was twice as likely to occur in the closed compared to the open group during the postoperative period (40% vs 18% P = 0.001). Implantation of the XEN45 with opening of the conjunctiva resulted in a lower IOP with greater success and lower needling rate compared with the closed conjunctiva technique. Similar rates of postoperative complications and vision loss were noted in each group. While both procedures provide substantial IOP reduction, the open technique appears to result in higher success rates and fewer postoperative interventions.