Comparison of subconjunctival microinvasive glaucoma surgery and trabeculectomy

Purpose To assess surgical success and the post-operative development of intraocular pressure between XEN45(R) gelstent, Preserflo(R) MicroShunt and trabeculectomy with mitomycin C. Methods Data from 105 eyes from 105 patients of matched cases with refractory open-angle glaucoma, who underwent surgery between January 2019, and August 2020, were evaluated. Patients underwent either stand-alone XEN gelstent insertion with Mitomycin C, stand-alone Preserflo with Mitomycin C or trabeculectomy with Mitomycin C. The primary outcome was the proportion of complete surgical success at 6 months post-operatively (i.e. intraocular pressure between 5mmHg and 18mmHg, no revision surgery, no loss of light perception and no post-operative pharmaceutical antiglaucomatous treatment). The reduction of intraocular pressure after 6 months, the classes of antiglaucomatous medication used post-operatively, best-corrected visual acuity, spherical refractive errors and astigmatism were assessed as secondary outcomes. Results We included 35 eyes in each group. After 6-month follow-up, complete success was 73.5% [95%-CI: 57.9%-89.2%] in the trabeculectomy group, 51.4% [95%-CI: 34.0%-68.8%] in the XEN group and 74.2% [95%-CI: 57.9%-90.5%] in the Preserflo group (p = 0.08). Regarding secondary outcomes, the reduction of intraocular pressure was 12.1 +/- 7.9 mmHg in the trabeculectomy group and was thereby 5.8 [95%-CI: 2.2-9.6] mmHg greater compared with the XEN group (p < 0.001) and 4.8 [95%-CI: 0.9-8.7] mmHg higher than the Preserflo group (p = 0.01). Conclusions No statistically significant differences were found between trabeculectomy, XEN45(R) gelstent implantation and Preserflo(R) MicroShunt implantation regarding surgical success after 6 months. Yet reduction in intraocular pressure was significantly higher in the trabeculectomy group. However, all three interventions resulted in sufficiently low post-operative intraocular pressure and may therefore be considered individually for glaucoma treatment.