LiGHT: Laser in Glaucoma and Ocular Hypertension Trial – Methodology and Baseline characteristics of a multicentre randomised controlled trial.

Abstract

Purpose : The Laser in Glaucoma and Ocular-Hypertension (LiGHT) Trial compares initial treatment with selective laser trabeculoplasty (SLT) versus topical medication for Primary Open Angle Glaucoma (POAG) and Ocular Hypertension (OHT).

Methods : LiGHT is a pragmatic, observer masked, multi-centre randomised controlled trial. 718 newly diagnosed patients with POAG or OHT were recruited at 6 collaborating centres in the United Kingdom between 2012-2014. Randomisation to SLT followed by conventional medical therapy as required or medical therapy without laser therapy was by done by an online web-based randomisation service, achieving full allocation concealment. Participants will be monitored for 3 years, according to routine clinical practice by masked observers. The target intraocular pressure (IOP) was based on disease severity and lifetime risk of loss of vision at recruitment and subsequently adjusted on the basis of IOP control and the stability of optic disc and visual field. The same decision support software determined treatment escalation and follow-up intervals to minimise bias. The primary outcome measure is Health Related Quality of Life (EQ-5D-5L). Secondary outcomes are treatment pathway cost and cost-effectiveness, Glaucoma Utility Index, Glaucoma Symptom Scale, Glaucoma Quality of Life, objective measures of pathway effectiveness, visual function and safety profiles and concordance. The sample size was determined for 90% power to detect a difference in mean EQ-5D-5L scores between treatment arms of 0.05 using a two-sample t-test at the 5% significance level, assuming a common standard deviation of 0.19 and allowing for 15% loss to follow-up at 36 months. A single main analysis will be performed at the end of the trial on an intention-to-treat basis.

Results : A total of 554 patients (77.2%) were classified as POAG and 163 patients (22.7%) as OHT. Median subject age was 63 years. The median IOP for OHT eyes was 26mmHg and 23mmHg for POAG eyes. The median for MD of baseline visual fields (VF) was -0.81dB for OHT eyes and -2.82dB for POAG eyes. POAG patients had similar median scores to OHT on the EQ-5D-5L (0.94) and GSS (85), higher scores on GQL (POAG 17, OHT 16) and lower GUI scores (POAG 0.90, OHT 0.93).

Conclusions : The LiGHT Trial will provide valuable data on HRQL, clinical- and cost-effectiveness of SLT and topical IOP lowering medication.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.