Laser trabeculoplasty as first-line glaucoma treatment
Authors: Jonathan W Young, Joesph Caprioli
Journal: The Lancet (2019)

The efficacy of laser trabeculoplasty as treatment for open-angle glaucoma is established.1Shingleton BJ Richter CU Dharma SK et al.Long-term efficacy of argon laser trabeculoplasty. A 10-year follow-up study.Ophthalmology. 1993; 100: 1324-1329Summary Full Text PDF PubMed Scopus (71) Google Scholar, 2Latina MA Sibayan SA Shin DH Noecker RJ Marcellino G Q-switched 532-nm Nd:YAG laser trabeculoplasty (selective laser trabeculoplasty): a multicenter, pilot, clinical study.Ophthalmology. 1998; 105: 2082-2088Summary Full Text Full Text PDF PubMed Scopus (355) Google Scholar The role of laser trabeculoplasty as first-line treatment was first reported in 1990: the Glaucoma Laser Trial3The Glaucoma Laser Trial (GLT)2. Results of argon laser trabeculoplasty versus topical medicines. The Glaucoma Laser Trial Research Group.Ophthalmology. 1990; 97: 1403-1413Summary Full Text PDF PubMed Scopus (212) Google Scholar showed that in patients with newly diagnosed primary open-angle glaucoma, argon laser trabeculoplasty was an effective and safe first-line therapy compared to topical timolol. Selective laser trabeculoplasty, which has the advantage of causing less target tissue disruption, superseded argon laser trabeculoplasty as the laser treatment of choice.4Juzych MS Chopra V Banitt MR et al.Comparison of long-term outcomes of selective laser trabeculoplasty versus argon laser trabeculoplasty in open-angle glaucoma.Ophthalmology. 2004; 111: 1853-1859Summary Full Text Full Text PDF PubMed Scopus (201) Google Scholar Randomised trials compared selective laser trabeculoplasty and latanoprost,5Katz LJ Steinmann WC Kabir A et al.Selective laser trabeculoplasty versus medical therapy as initial treatment of glaucoma: a prospective, randomized trial.J Glaucoma. 2012; 21: 460-468Crossref PubMed Scopus (134) Google Scholar and established selective laser trabeculoplasty as a safe and effective first-line treatment. Physicians' habits die hard, and the simplistic algorithm of giving drops first, then laser, then surgery is engrained in practice and teaching. LiGHT was a multicentre trial sponsored by the National Institute for Health Research comparing selective laser trabeculoplasty to medicine in newly diagnosed patients with ocular hypertension and open-angle glaucoma, reported in The Lancet by Gus Gazzard and colleagues.6Gazzard G Konstantakopoulou E Garway-Heath D et al.Selective laser trabeculoplasty versus eye drops for first-line treatment of ocular hypertension and glaucoma (LiGHT): a multicentre randomised controlled trial.Lancet. 2019; (published online March 9.)http://dx.doi.org/10.1016/S0140-6736(18)32213-XSummary Full Text Full Text PDF PubMed Scopus (231) Google Scholar 718 patients were randomly assigned to receive either selective laser trabeculoplasty first or topical medicine first. The trial showed that health-related quality-of-life and other disease-specific quality-of-life outcomes did not differ between treatment groups. The primary outcome, average EQ-5D score, was 0·89 (SD 0·18) in the selective laser trabeculoplasty group versus 0·90 (SD 0·16) in the eye drops group (difference 0·01, 95% CI −0·01 to 0·03; p=0·23). However, secondary outcomes including cost-effectiveness, clinical effectiveness, and safety favoured the group who received selective laser trabeculoplasty first. Within the UK health-care system, the 3-year cost savings were impressive: each patient who received selective laser trabeculoplasty first could save the equivalent of five ophthalmology specialist appointments. The strength of this work lies in its methods. The authors generated target intraocular pressures for each patient based on internationally recognised guidelines7Damji KF Behki R Wang L Target IOP Workshop participantsCanadian perspectives in glaucoma management: setting target intraocular pressure range.Can J Ophthalmol. 2003; 38: 189-197Summary Full Text PDF PubMed Scopus (72) Google Scholar, 8Gazzard G Konstantakopoulou E Garway-Heath D et al.Laser in Glaucoma and Ocular Hypertension (LiGHT) trial. A multicentre, randomised controlled trial: design and methodology.Br J Ophthalmol. 2018; 102: 593-598Crossref PubMed Scopus (39) Google Scholar and used these targets to monitor efficacy. Decision-tree algorithms escalated treatment when pressures were beyond the target in a manner that resembles how contemporary glaucoma specialists treat their patients. It may be argued that this target is complex and arbitrary, reducing the generalisability of the trial's results. However, many glaucoma trials measured the percentage of patients achieving a given intraocular pressure or a percentage decrease, which is easier to apply, but is also arbitrary and probably too simplistic. Indeed, LiGHT's methodology might become a rubric for future glaucoma trials. Some details of the study are noteworthy. First, the overall effectiveness of selective laser trabeculoplasty in this trial seemed greater than in previous trials. At the end of 3 years, 21·8% of patients treated with selective laser trabeculoplasty required additional medications, whereas previous trials showed that after approximately 1 year 20–30% of patients required additional therapy.5Katz LJ Steinmann WC Kabir A et al.Selective laser trabeculoplasty versus medical therapy as initial treatment of glaucoma: a prospective, randomized trial.J Glaucoma. 2012; 21: 460-468Crossref PubMed Scopus (134) Google Scholar, 9Nagar M Ogunyomade A O'Brart DP Howes F Marshall J A randomised, prospective study comparing selective laser trabeculoplasty with latanoprost for the control of intraocular pressure in ocular hypertension and open angle glaucoma.Br J Ophthalmol. 2005; 89: 1413-1417Crossref PubMed Scopus (206) Google Scholar This difference might arise from LiGHT's use of individualised target pressures, which could adjust target pressures upward if there is no confirmed worsening for a particular patient. The frequency of this upward adjustment and the absolute reduction in intraocular pressure thanks to selective laser trabeculoplasty was not reported and is a limitation; the authors say that will provide these details in future papers. LiGHT included patients with ocular hypertension, while other studies of selective laser trabeculoplasty focused on patients with open-angle glaucoma. Selective laser trabeculoplasty may be more effective for ocular hypertension, or seem to be more effective, especially when effectiveness depends on potentially upwardly mobile target pressures. Potential long-term negative effects of selective laser trabeculoplasty on trabecular meshwork function are of course impossible to determine in such a trial. Finally, there might be unintended consequences of treating patients with selective laser trabeculoplasty and following them up off medication. Not taking medications is one reason for patient non-attendance to chronic disease clinics.10Paterson BL Patricia C Simon R Non-attendance in chronic disease clinics: a matter of non-compliance?.J Clin Nurs. 2010; 2: 63-74Google Scholar Medication refills often remind patients to attend important follow-up examinations. From a practical standpoint, an ophthalmologist will need to gauge a patient's reliability prior to recommending medication versus selective laser trabeculoplasty. A mandate of selective laser trabeculoplasty first for short-term economic gain may lead to worse outcomes in patients whose understanding of their glaucoma is limited, or because of unforeseen, untoward long-term effects. Overall, LiGHT was a well designed trial that demonstrates selective laser trabeculoplasty's acceptable safety and efficacy. Based on UK standards, the 3-year cost savings for giving selective laser trabeculoplasty first appear to be substantial. In the USA, where the price of medications is higher than in some single-payer systems, the cost savings might be even greater. In an ageing population, as glaucoma is becoming more prevalent and medical costs are escalating, the LiGHT trial provides evidentiary support for ophthalmologists to consider selective laser trabeculoplasty as first-line treatment for ocular hypertension and open-angle glaucoma. We declare no competing interests. Selective laser trabeculoplasty versus eye drops for first-line treatment of ocular hypertension and glaucoma (LiGHT): a multicentre randomised controlled trialSelective laser trabeculoplasty should be offered as a first-line treatment for open angle glaucoma and ocular hypertension, supporting a change in clinical practice. Full-Text PDF Open Access