One-year outcomes of microhook trabeculotomy versus suture trabeculotomy ab interno

Purpose To compare clinical success rates and reductions in intraocular pressure (IOP) and IOP-lowering medication use following suture trabeculotomy ab interno (S group) or microhook trabeculotomy (mu group). Methods This retrospective review collected data from S (n = 104, 122 eyes) and mu (n = 42, 47 eyes) groups who underwent treatment between June 1, 2016, and October 31, 2019, and had 12-month follow-up data including IOP, glaucoma medications, complications, and additional IOP-lowering procedures. The Kaplan-Meier survival analysis was used to evaluate treatment success rates defined as normal IOP (> 5 to <= 18 mm Hg), >= 20% reduction of IOP from baseline at two consecutive visits, and no further glaucoma surgery. Results Schlemm's canal opening was longer in the S group than in the mu group (P < 0.0001). The Kaplan-Meier survival analysis of all eyes showed cumulative clinical success rates in S and mu groups were 71.1% and 61.7% (P = 0.230). The Kaplan-Meier survival analysis of eyes with preoperative IOP >= 21 mmHg showed cumulative clinical success rates in S and mu groups were 80.4% and 60.0% (P = 0.0192). There were no significant differences in postoperative IOP at 1, 3, and 6 months (S group, 14.9 +/- 5.6, 14.6 +/- 4.5, 14.6 +/- 3.9 mmHg; mu group, 15.8 +/- 5.9, 15.2 +/- 4.4, 14.7 +/- 3.7 mmHg; P = 0.364, 0.443, 0.823), but postoperative IOP was significantly lower in the S group at 12 months (S group, 14.1 +/- 3.1 mmHg; mu group, 15.6 +/- 4.1 mmHg; P = 0.0361). There were no significant differences in postoperative numbers of glaucoma medications at 1, 3, 6, and 12 months (S group, 1.8 +/- 1.6, 1.8 +/- 1.5, 2.0 +/- 1.6, 1.8 +/- 1.5; mu group, 2.0 +/- 1.6, 2.0 +/- 1.6, 2.1 +/- 1.6, 2.2 +/- 1.7; P = 0.699, 0.420, 0.737, 0.198). Conclusion S and mu group eyes achieved IOP reduction, but mu group eyes had lower clinical success rates among patients with high preoperative IOP at 12 months.