Efficacy of selective laser trabeculoplasty in primary angle-closure glaucoma: a randomized clinical trial.

Importance: Selective laser trabeculoplasty (SLT) should be explored as a therapeutic option in eyes with angle closure.
Objective: To assess the intraocular pressure (IOP)-lowering efficacy of SLT in eyes with primary angle closure (PAC) and PAC glaucoma (PACG).
Design, Setting, and Participants: Randomized clinical trial at tertiary eye care institutions of 100 patients diagnosed as having PAC or PAC glaucoma in which the angles had opened at least 180° (visible posterior trabecular meshwork on gonioscopy) after laser iridotomy. Recruitment and baseline were completed from June 2009 to April 2012 and 6-month follow-up was completed from December 2009 to November 2012.
Interventions: Eligible patients with a baseline IOP greater than 21 mm Hg were randomized to either SLT or prostaglandin analog (PGA; travoprost, 0.004%). The SLT was repeated if the IOP reduction was less than 20.0% from baseline at the 1- or 3-month follow-up visit.
Main Outcomes and Measures: The primary outcome measure was the change in IOP from baseline to the final follow-up visit (at 6 months). The frequency of additional postoperative treatments and complications were secondary outcomes.
Results: Fifty patients (96 eyes) were randomized to SLT and 50 patients (99 eyes) to PGA medical therapy. At 6 months, 49 patients in the SLT group and 47 in the PGA group completed follow-up. Analysis was based on intent to treat. At 6 months, IOP decreased by 4.0 mm Hg (95% CI, 3.2-4.8) in the SLT group (P < .001) and by 4.2 mm Hg (95% CI, 3.5-4.9) in the PGA group (P < .001). There were no differences between the SLT and PGA groups in the absolute mean reduction of IOP (4.0 vs 4.2 mm Hg, respectively; P = .78) or in the percentage of reduction in IOP (16.9% vs 18.5%, respectively; P = .52). Complete success (IOP ≤21 mm Hg without medications) was achieved in 60.0% eyes of the SLT group, compared with 84.0% of eyes in the PGA group (P = .008). No patients required glaucoma surgery. Additional medications were required in 22.0% of patients in the SLT group compared with 8.0% in the PGA group (P = .05). One patient in the SLT group (2.0%) had a transient posttreatment IOP spike greater than 5 mm Hg. The mean endothelial cell count showed a significant decrease from baseline in the SLT arm (4.8% decrease; P = .001). No other events such as persistent uveitis or increase in peripheral anterior synechiae were noted in eyes that underwent SLT. Two patients in the PGA group exited owing to drug-related complications (1 patient with uveitis and 1 with allergic conjunctivitis).
Conclusions and Relevance: Eyes with PAC or PACG respond to SLT in the short term, but the overall long-term therapeutic effectiveness needs further evaluation.
Trial Registration: clinicaltrials.gov Identifier: NCT01004900.