Impact of laser pulse duration on the reduction of intraocular pressure during selective laser trabeculoplasty.

Purpose: To evaluate the efficacy of selective laser trabeculoplasty (SLT) to lower intraocular pressure (IOP) in patients with primary open-angle glaucoma (POAG), normal tension glaucoma (NTG) or ocular hypertension (OHT), when performed with laser pulse duration of 1 ns compared with standard 3-5 ns.Methods: Bilateral SLT with a 532 nm Q-switched neodymium-doped yttrium aluminium garnet laser was conducted in 30 patients (60 eyes) with POAG (<italic>n</italic> = 5), NTG (<italic>n</italic> = 2) or OHT (<italic>n</italic> = 23). Pulse duration was 1 ns in the right eye (30 eyes; cases) and 3-5 ns in all left eyes (controls). Main outcome measures were IOP at 1 h, 1 day, 8 weeks and 6 months, and the rate of adverse ocular tissue reactions in all eyes.Results: Mean 1 ns and 3-5 ns SLT IOPs were 24.1 and 24.3 mmHg, respectively, at baseline. No statistically significant difference in mean 1 ns and 3-5 ns SLT IOP was observed at 1 h (<italic>P</italic> = 0.761), 1 day (<italic>P</italic> = 0.758), 8 weeks (<italic>P</italic> = 0.352) and 6 months postoperatively (<italic>P</italic> = 0.879). No significant difference in postoperative anterior chamber inflammation was observed between the eyes (<italic>P</italic> = 0.529). Treatment with both laser pulse durations resulted in minor ultrastructural changes in the drainage angle.Conclusions: SLT performed with a 1 ns laser pulse duration does not appear to be inferior to SLT performed with the standard 3-5 ns duration at lowering IOP in treatment-naïve patients with POAG, NTG or OHT. [ABSTRACT FROM AUTHOR]