A Comparison of Clinical Outcomes After XEN Gel Stent and EX-PRESS Glaucoma Drainage Device Implantation

Abstract

Precis: Although the XEN stent offers a lower risk of hypotony and choroidal effusions with fewer clinic visits postoperatively, its surgical success rate was inferior to the EX-PRESS shunt.Purpose: To compare the clinical efficacy and safety outcomes of the XEN stent and EX-PRESS glaucoma drainage device in glaucomatous eyes.Materials and Methods: One hundred eyes from 88 patients underwent ab interno XEN stent or EX-PRESS shunt implantation (52 XEN and 48 EX-PRESS) for uncontrolled glaucoma at the University of Colorado Eye Center. The primary outcome was surgical success defined as intraocular pressure (IOP) ≥ 6 and ≤ 18 mm Hg, without reoperation for uncontrolled glaucoma, loss of light perception, or use of glaucoma medications (complete success). Secondary outcomes were the same requirements allowing for medications (qualified success), mean IOP, medication use, adverse events, and number of postoperative clinic visits in the first 3 months.Results: Baseline characteristics including glaucoma type and severity were similar between groups, with the exception of XEN patients having fewer men (17% vs. 46%), older patients (median age, 78 vs. 68), and a higher percentage of white patients (89% vs. 69%). Adjusted hazard ratio of failure of XEN relative to EX-PRESS was 3.94 (95% confidence interval, 1.73-9.00, P = 0.001) for complete success and 1.61 (95% confidence interval, 0.40-6.38, P = 0.501) for qualified success. There were significantly fewer postoperative clinic visits during the first 3 months in the XEN group (5.3 vs. 9.1 visits, P < 0.001). The incidence of serous choroidal effusions and hypotony was significantly less after XEN compared with EX-PRESS (1 vs. 9, P = 0.02 and 15 vs. 25, P = 0.023, respectively). Three XEN stents (5.8%) required removal. Conclusions:In this population, although the XEN stent offers a better safety profile and fewer postoperative clinic visits, complete surgical success was inferior to the EX-PRESS shunt.

The Outcomes of XEN Gel Stent Implantation: A Systematic Review and Meta-Analysis

“…However, some studies focused on the efficacy of XEN implantation in the treatment of secondary openangle glaucoma, including pseudoexfoliative glaucoma (52,60,(67)(68)(69)(70) and glaucoma secondary to uveitis (34). Furthermore, a few studies introduced this gel stent to narrow-or closeangle glaucoma (13,15,16,(18)(19)(20)(21)50). All patients were treated and followed as routine clinical practice between May 2013 and February 2020.…”

“…Cases of stent malposition needed to remove or reimplant of the stent (12). Bleb-related complications comprised bleb leakage (0.68%) and dysesthetic blebs (0.01%) that required sutures (34,53) or revisions (15,35,75).…”

“…The requirements for bleb needling and additional glaucoma surgery procedures were similar in both groups. In another study comparing XEN implantation and EX-PRESS drainage device implantation (15), EX-PRESS showed superiority in terms of success rate although XEN implantation could reduce the risk of hypotony and choroidal effusion with fewer postoperative clinical visits. In another 9-month followup study, non-penetrating deep sclerectomy (NPDS) with MMC was compared with XEN gel stent implantation with MMC (48).…”

“…Other types of glaucoma include pigmentary glaucoma, uveitic secondary glaucoma, juvenile open-angle glaucoma, and steroid-induced glaucoma, etc. Some studies enrolled patients with ocular hypertension to reduce IOP (12)(13)(14)(15)(16). Other studies introduced XEN to patients with primary angle-closure glaucoma (PACG), although it was originally a contraindication (9,13,(16)(17)(18)(19)(20)(21).…”

Comparison of surgical outcomes between initial trabeculectomy and Ex-PRESS in terms of achieving an intraocular pressure below 15 and 18 mmHg: a retrospective comparative study

“…The results of Xen vs. EX were 15.6% vs. 55.6% and 17.8% vs. 55.6%, respectively. Therefore, they concluded that Xen was inferior to EX for complete success [ 29 ]. Further studies are needed to determine whether all filtering surgeries using MMC for controlling IOP via laser suture lysis through a scleral flap are superior to single insertion Xen and Preserflo.…”