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 1 st , 2021 and July 31 st , 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 1 st , 2017 and April 30 th , 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±5.07mmHg vs. 13.17±3.81mmHg; 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 preand 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.