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

Abstract

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 21mmHg 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 measurewas 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 4.0mmHg (95%CI, 3.2-4.8) in the SLT group (P <.001) and by 4.2mmHg (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 4.2mmHg, respectively; P =.78) or in the percentage of reduction in IOP (16.9%vs 18.5%, respectively; P =.52). Complete success (IOP 21mmHg 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 5mmHg. 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.