To compare 3-year post-operative efficacy and safety of standalone ab interno gelatin microstent (Xen45®) versus trabeculectomy.

This is a single-center retrospective cohort study. Patients included were 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.

Inclusion Criteria:

• Patients aged 30-90
• primary or pigmentary/pseudoexfoliative open angle, primary closed angle, narrow angle or combined mechanism glaucoma
• IOP of 18-40 on maximum tolerated medical therapy
• received a gelatin stent 45 with MMC or a trabeculectomy with MMC at Prism Eye Institute from June 2012 to July 2018, and have at least 3 years of follow-up.

Exclusion Criteria:

• Other forms of glaucoma
• prior incisional glaucoma surgery
• CPC
• combined surgery (cataract, cornea, or retina)
• prior corneal graft (PKP, DALK, DSAEK, DMEK)

Glaucoma patients who received received a gelatin stent 45 with MMC (mitomycin C) or a trabeculectomy with MMC