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

Original Paper



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.


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.


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.


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.


Intraocular pressure Trabeculoplasty Q-switched lasers 


Financial disclosure

Prof. Brigita Drnovšek-Olup, MD PhD is a medical consultant for Optotek d.o.o, Slovenia.

Compliance with ethical standards

Conflict of interest

Author Spela Stunf Pukl declares that she has no conflict of interest. Author Brigita Drnovšek-Olup is a medical consultant for Optotek.

Ethical approval

All procedures performed in the studies involving human participants were in accordance with the ethical standards of the institutional and national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.

Informed consent

Informed consent was obtained from all individual participants included in the study.


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Copyright information

© Springer Science+Business Media Dordrecht 2016

Authors and Affiliations

  1. 1.Eye Hospital, University Clinical CenterLjubljanaSlovenia

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