Primary Deep Sclerectomy in Open-Angle Glaucoma: Long-Term Outcomes and Risk Factors for Failure

Abstract

To report long-term outcomes of primary deep sclerectomy (DS) in open-angle glaucoma (OAG) and identify factors influencing surgical failure and postoperative complications. Retrospective cohort study. Consecutive OAG patients undergoing primary DS with follow-up of 1 year or more. Three intraocular pressure (IOP) success cutoffs were defined: 18 mmHg or less and 20% reduction, 15 mmHg or less and 25% reduction, and 12 mmHg or less and 30% reduction. Cox multivariable regression analysis investigated factors influencing failure and postoperative complications. The primary outcome was the success rate of DS according to the defined criteria. Secondary outcomes included IOP over time and factors predictive of failure. Five hundred thirteen eyes of 409 patients with a mean age ± standard deviation (SD) of 70.2 ± 9.8 years and follow-up of 84.1 ± 41.6 months. Mean ± SD IOP decreased from 23.5 ± 7.3 mmHg to 13.3 ± 3.9 mmHg, 12.8 ± 4.3 mmHg, and 12.4 ± 4.3 mmHg at 3, 5, and 7 years, respectively (P < 0.001). Success rates at 3, 5, and 7 years were 66.3% (95% Confidence Interval [CI] 62.2%-70.7%), 57.9% (95% CI 53.4%-62.7%), and 54.0% (95% CI 49.4%-59.1%), respectively, for IOP of 18 mmHg or less; 44.5% (95% CI 40.3%-49.1%), 34.6% (95% CI 30.4%-39.4%), and 29.8% (95% CI 25.6%-34.6%), respectively, for IOP of 15 mmHg or less; and 18.1% (95% CI 15.0%-21.9%), 11.9% (95% CI 9.2%-15.4%), and 10.0% (95% CI 7.5%-13.4%), respectively, for IOP of 12 mmHg or less. For all cutoffs, laser goniopuncture (P < 0.001), needling (P < 0.001), and postoperative antiglaucoma medications (P <0.001) were associated with increased failure. Intraoperative mitomycin C (MMC) was associated with reduced failure for IOP of 15 mmHg or less (P= 0.006) and IOP of 12 mmHg or less (P= 0.001), whereas higher preoperative IOP (P= 0.001) with increased failure for IOP of 12 mmHg or less. Deep sclerectomy is an effective, long-lasting primary surgical procedure for OAG. Intraoperative MMC enhances survival, whereas higher preoperative IOP and postoperative maneuvers are predictors of increased failure.