Clinical outcomes of Xen 45 gel stent implantation(Ab externo, open conjunctival approach) versus Trabeculectomy: A real world study.

Purpose: To compare the clinical outcomes of Xen 45 gel stent implantation surgery (Ab externo, open conjunctiva) with those of trabeculectomy.

Method: We retrospectively reviewed electronic medical record of 57patients (62eyes) treated with Xen implantation surgery (ab externo, open conjunctiva approach) between April 1st, 2021 and July 31st, 2023 by the same surgeon. Preoperative clinical data including intraocular pressure, the number of glaucoma medications, visual acuity were collected from 1 day to 12 months postoperatively. These data were compared and analyzed with those of 67patients (78eyes) received trabeculectomy between February 1st, 2017 and April 30th, 2022 by the same surgeon. Statistical analyses were performed with P<0.05 as significant.

Results: Complete surgical success rate was 33.9% and 57.7% of the Xen and trabeculectomy groups, respectively(p=0.005). Qualified success rate was 79.0% and 93.6%, respectively(p=0.011). Postoperatively, the Xen group used more glaucoma medications than the Trabeculectomy group (1.21±1.05 vs. 0.69±0.90; p=0.003, at postoperative month 12). After postoperative month 1, the Xen group had a higher IOP (15.77±5.07 mmHg vs. 13.17±3.81 mmHg; p=0.001, at postoperative month 12) and lower corneal astigmatism than the trabeculectomy group (1.32±0.79 vs. 1.88±1.45; p=0.020, at postoperative month 6). There was no significant difference in pre- and postoperative best corrected visual acuity (logMAR) between the groups at any of the follow-up period (favorable VA subgroup; logMAR<0.7). Postoperative complications were 0 case of Xen group and 13 cases of trabeculectomy group (0% vs. 16.7%; p=0.001). Also, Xen surgery(24minutes 40seconds±6minutes 26seconds) had a shorter operation time than the trabeculectomy(40minutes 18seconds±8minutes 27seconds; p<0.001).

Conclusion: Compared to trabeculectomy, Xen surgery (Ab externo, open conjunctiva) showed relatively lower effectiveness (surgical success rate, IOP reduction). However, it demonstrated advantages as a MIGS, including a surgical success rate approaching about 80%, stability in inducing corneal astigmatism, fewer postoperative complications, and shorter operation times.