Purpose:

To compare 3-year post-operative efficacy and safety of standalone ab interno gelatin microstent (Xen45®) versus trabeculectomy. There is currently no published long-term data on the Xen45®, nor long-term comparative data with trabeculectomy.

Methods:

This is a single-center retrospective cohort study including consecutive patients from June 2012 – July 2017 who received standalone Xen45® or standalone trabeculectomy. The primary outcome was time to failure, defined as intraocular pressure (IOP) outside of 6mmHg – 17mmHg on no medications on two consecutive visits despite in-clinic maneuvers (including needling). Secondary outcomes included IOP cutoffs of 14mmHg and 21mmHg with and without medications, as well as interventions, complications, and reoperations.

Results:

A total of 173 eyes in 160 patients received Xen45® and 82 eyes in 71 patients received trabeculectomy. Hazard Ratio for Xen45® relative to trabeculectomy was 1.28 (95% CI 0.95-1.72). Proportional complete success at 1, 2, and 3 years for Xen45® were 0.61 (.04), 0.50 (0.04), and 0.42 (0.04) and for trabeculectomy were 0.73 (0.05), 0.58 (0.06), and 0.52 (0.06). Both Xen45® and trabeculectomy had a similar number of interventions (66% vs. 68%, p=0.77), most of which were needling, and a similar number of complications (75% vs. 71%, p=0.52), most of which were transient. There was a higher rate of reoperation with Xen45® (32.4% vs. 19.5%), which was significant (p=0.03).

Conclusions:

Standalone ab interno gelatin microstent (Xen45®) demonstrated a good success rate and safety profile at 3 years post-operative follow-up, comparable to standalone trabeculectomy - although with a higher reoperation rate.