Short-Term Efficacy of Selective Laser Trabeculoplasty in Primary Angle Closure Disease - Results of a Randomized Controlled Trial

Abstract

 

Purpose:

 

To assess the intraocular pressure (IOP) lowering efficacy of selective laser trabeculoplasty (SLT) over 6 months in eyes with primary angle closure (PAC) and primary angle closure glaucoma (PACG).

 

Methods:

 

Sixty subjects (93 eyes) diagnosed as PAC/PACG with at least 180 degrees of visible posterior trabecular meshwork on gonioscopy after laser iridotomy were enrolled in this prospective multi-centre randomized study. Subjects with a baseline IOP >21 mmHg were randomized to either SLT or medical therapy (prostaglandin analog).Repeat SLT was performed if the IOP reduction of less than 20% from baseline was noted at Month 1 or 3 visit. The primary outcome measure was the change in IOP from baseline at 6 months. Further treatment modification in the form of additional medication was administered if the IOP was > 21 mm Hg (after a maximum of 2 laser sittings in the SLT group) and was considered as criteria for failure.

 

Results:

 

Thirty subjects (45 eyes) were randomized to SLT and 30 subjects (48 eyes) to medical therapy. Data from one eye per subject was included in the final analysis. At baseline, there were no significant differences between the groups in terms of demographic features, diagnoses, extent of peripheral anterior synechiae, vertical cup-to-disc ratio or visual field indices. There were no differences in the mean baseline IOP between the SLT group and the medication group (23.2 ± 2.5 Vs 22.4± 1.8 mm Hg; p =0.2). Mean extent of angle treated by SLT was 329 (54.2) degrees and 23.3 % of eyes received SLT twice. At 6 months, IOP decreased by 4.8 mm Hg (95% Confidence Interval [CI]:3.8-5.8 mm Hg) in the SLT group (P<0.001) and by 4.1 mm Hg (95%CI: 3.4-4.9 mm Hg) in the medication group (p <0.001). There were no differences noted either in the absolute mean reduction of IOP (4.8 Vs 4.1 mm Hg; p= 0.6) or in the percentage reduction in IOP (20.6% Vs 18.8 %; p= 0.9) between the groups. A failure rate of 16.7% was noted in the SLT group compared to 10.0 % in the medication group (p=0.7). One subject had an acute IOP spike in the SLT group. No other complications were recorded in either of the groups.

 

Conclusions:

 

The IOP lowering efficacy of SLT over 6 months was observed to be similar to prostaglandin analogues in eyes with PAC and PACG.

 

Clinical Trial:

 

http://www.clinicaltrials.gov NCT01004900

 

Keywords: laser • clinical (human) or epidemiologic studies: systems/equipment/techniques • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials