Attaining Intraocular Pressure of ≤10 mm Hg: Comparison of Tube and Trabeculectomy Surgery in Pseudophakic Primary Glaucoma Eyes

The aim of this study is to evaluate whether trabeculectomy with antimetabolites or glaucoma drainage device (GDD) surgery is more likely to achieve an intraocular pressure (IOP) ≤10 mm Hg. DESIGN: Retrospective, nonrandomized, cohort study of pseudophakic, primary glaucoma patients. METHODS: 53 pseudophakic patients underwent trabeculectomy and 65 received GDD at the University of Florida by one surgeon between 1993 and 2015. The main outcome measures were mean IOP and percentage of patients obtaining an IOP ≤10 mm Hg for up to 5 years postoperatively. A subgroup undergoing a first time glaucoma surgery was also analyzed because there were more redo glaucoma procedures in the GDD group. RESULTS: Over 5 years, the mean annual IOP for the trabeculectomy eyes was between 6.9 and 7.8 mm Hg on an average of 0.2 medications, and that for GDD eyes was between 11.4 and 12.1 mm Hg on a mean of 1.6 to 1.9 medications (P < 0.002). A significantly higher percentage of trabeculectomy eyes than GDD eyes achieved a pressure of ≤10 mm Hg, for years 1 to 4 (P < 0.05). Visual acuity (VA) change was not statistically different between the groups, both for mean logMAR acuity and percentage of patients that lost ≥2 Snellen lines. Complication rates were similar between the groups. Postoperative VA change was similar for eyes achieving low IOP ≤5 mm Hg and those eyes with an IOP ≥10 mm Hg. CONCLUSIONS: Trabeculectomy provided significantly lower IOP for 5 years postoperatively in pseudophakic primary glaucoma patients, and was more likely to achieve an IOP ≤10 mm Hg.