Effectiveness and safety of XEN63 in patients with primary-open-angle glaucoma

Abstract

This paper evaluates the effectiveness and safety of XEN63 stent, either standalone or in combination with phacoemulsification, in patients with primary open-angle glaucoma (POAG). Eighty eyes from 80 patients with medically uncontrolled POAG were assigned to undergo XEN63 implant. The primary outcome was the surgical success, defined as an intraocular pressure (IOP) lowering from preoperative values ≥ 20% and an IOP absolute value between 6 and 18 mmHg, with or without antiglaucoma medications. Forty-three (53.7%) eyes underwent XEN63-standalone and 37(46.2%) eyes a XEN63 + Phacoemulsification procedure. Success rate was 68.8% (55/80) eyes in the overall study sample, 69.8% (30/43) eyes in the XEN63-standalone group; and 67.6% (25/37) eyes in the XEN63 + Phaco group (p = 0.6133). Preoperative IOP was significantly lowered from 22.1 ± 4.9 mmHg and 19.8 ± 3.7 mmHg to 14.7 ± 5.3 mmHg and 13.8 ± 3.4 mmHg in the XEN63-standalone and XEN63 + Phaco groups, respectively (p < 0.0001 each, respectively); without significant differences between them at any of the time-points measured. Preoperative number of ocular-hypotensive drugs was significantly reduced from 2.3 ± 0.8 to 0.3 ± 0.7 drugs, from 2.5 ± 0.7 to 0.3 ± 0.7 drugs; and from 2.0 ± 0.8 to 0.3 ± 0.7 drugs, in the overall, XEN63-standalone, and XEN63 + Phaco groups, respectively. Regarding safety, 3(42.5%) eyes had transient hypotony at some point during the study, although only in one (1.2%) eye was clinically significant. Four (5.0%) eyes underwent a needling, 4 (5.0%) eyes underwent surgical-bleb-revision, 1 (1.2%) eye required a device replacement and 1 (1.2%) eye a device removal due to maculopathy. XEN63, either alone or in combination with phacoemulsification, significantly lowered IOP and reduced the number of ocular hypotensive medications. The rate of ocular hypotony was relatively high, although it was clinically relevant only in one eye.

Keywords: Bleb forming devices; Glaucoma; IOP; MIGS; Primary open-angle glaucoma; Subconjunctival MIGS.

Figure 1

Kaplan–Meier survival analysis. The grey area represents the 95% confidence interval. (A) In the overall study population. (B) Kaplan–Meier survival curves for surgical success in eyes treated with XEN63-standalone and XEN63 + Phacoemulsification (XEN63 + Phaco). Mean hazard ratio: 1.28; 95% CI: 0.56 to 2.91; p = 0.5555.

Figure 2

Mean intraocular pressure (IOP) in the overall study sample (A) and in the XEN63-standalone and XEN63 + Phaco eyes (B) throughout study follow-up. Vertical bars represent standard deviation. Intergroup statistical significance, at the different time point measurements, was determined using the one-way ANOVA test with the Scheffé's method. As compared to baseline, the mean IOP was significantly reduced, at every time point measured, p < 0.0001 (repeated measures ANOVA and the Greenhouse–Geisser correction).

Figure 3

Unadjusted mean intraocular pressure lowering in the XEN63-standalone and XEN63 + Phaco groups. Vertical bars represent 95% confidence Interval. Statistically significance between groups was calculated with the two-tailed Mann–Whitney U test.