Objective: Whereas achieving intraocular pressure (IOP) targets ≤ 10 mm Hg typically requires surgical intervention, we sought to examine the safety and efficacy of trabeculectomy in normal-tension glaucoma (NTG).

Methods: Patients with progressive NTG undergoing trabeculectomy with preoperative IOP ≤ 15 mm Hg during the 12-month period before surgery were identified at a single academic institution. Failure was defined as IOP reduction <20% below baseline (criteria A), <30% (criteria B), or <40% (criteria C), reoperation for glaucoma, or loss of light perception vision.

Results: Thirty eyes of 28 patients (mean age, 73 ± 8.7 y) were enrolled with a mean follow-up period of 50 ± 31 months. Mean postoperative IOP (8.6 ± 2.9 mm Hg) and medications (0.6 ± 1.0) at final follow-up was significantly (P<0.001) reduced compared with before surgery (13.2 ± 1.4 mm Hg and 2.5 ± 1.2, respectively). The cumulative probability of failure during 5 years of follow-up was 32% (criteria A), 48%, (criteria B), and 67% (criteria C). The probability of successfully achieving an IOP goal ≤ 10 mm Hg was 68% at 4 years of follow-up.

Conclusions: Trabeculectomy is a safe and effective method for achieving single-digit IOP targets in NTG eyes with progression at low IOP.