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)