title: Impact of laser pulse duration on the reduction of intraocular pressure during selective laser trabeculoplasty.
abstract: OBJECTIVE
  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 (n = 5), NTG (n = 2) or OHT (n = 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 (P = 0.761), 1 day (P = 0.758), 8 weeks (P = 0.352) and 6 months postoperatively (P = 0.879). No significant difference in postoperative anterior chamber inflammation was observed between the eyes (P = 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.
authors.affiliation: Eye Hospital, University Clinical Center, Barvarska 4, 1000, Ljubljana, Slovenia. spela.stunf@siol.net.
authors.forename: Spela
authors.initials: S
authors.lastname: Stunf Pukl
authors.affiliation: Eye Hospital, University Clinical Center, Barvarska 4, 1000, Ljubljana, Slovenia.
authors.forename: Brigita
authors.initials: B
authors.lastname: Drnovšek-Olup
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D005902:Glaucoma, Open-Angle / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure / Q000528:radiation effects*; D053685:Laser Therapy / Q000379:methods*; D053844:Lasers, Solid-State; D057066:Low Tension Glaucoma / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000503:physiopathology / Q000601:surgery*; D011446:Prospective Studies; D014065:Tonometry, Ocular; D014130:Trabeculectomy / Q000379:methods*
keywords: Intraocular pressure; Q-switched lasers; Trabeculoplasty