View commentaries on this research

This is a plain English summary of an original research article

Using a laser to improve drainage of fluid within the eye showed similar results to eye drops as a first-line treatment for adults with open angle glaucoma or ocular hypertension (raised pressure in the eye). It improved vision without increasing the risk of adverse events. It was preferred by patients and also associated with lower costs.

Current guidelines recommend that eye drops are used first to lower the pressure in the eye and slow the progression of glaucoma. Many patients find eye drops inconvenient and difficult to use and don’t continue with treatment. This NIHR-funded trial, which included 718 patients from six hospitals in the UK, showed that selective laser trabeculoplasty is a good alternative treatment. Almost 75% of those who had the procedure didn’t need to use eye drops at all for three years afterwards.

The trial provides good quality evidence to support a change in clinical practice.

Why was this study needed?

Glaucoma can lead to blindness if untreated. It is caused by raised pressure in the eye (called ocular hypertension) which leads to damage to the nerves within the eye. Ocular hypertension affects around 3-5% of people in the UK who are over 40. Glaucoma is one of the commonest causes for outpatient ophthalmology appointments in the NHS, accounting for more than 10% of attendances.

There are several different types of glaucoma, the most common being open angle glaucoma. Treatment for open angle glaucoma focuses on lowering intraocular pressure, usually with medicated eye drops. Laser trabeculoplasty uses a laser to open up the drainage tubes within the eye, allowing more fluid to drain out and reducing the pressure.

This study aimed to compare the two treatments, and included a cost-effectiveness analysis.

What did this study do?

This randomised controlled trial recruited patients with either ocular hypertension or open angle glaucoma. Eye drops were given to 362 patients, and 356 had selective laser trabeculoplasty. The eye drops group were given prostaglandin analogue drops as first-line treatment, which could be escalated according to guidelines as necessary. The selective laser trabeculoplasty group were given eye drops after the procedure if needed.

Participants were monitored for 36 months, according to an individualised plan. They also completed postal questionnaires every six months, reporting their symptoms, compliance with treatment, and quality of life.

These self-reported outcomes, and patients and clinicians not being blind to their treatment allocation, are limitations that may have introduced some bias to the trial.

What did it find?

  • Health-related quality of life was similar in the two groups after 36 months. This was assessed using the EQ-5D tool, which gives a score between 0 and 1, with higher scores indicating a better quality of life. The average EQ-5D score in the selective laser trabeculoplasty group was 0.89 (standard deviation [SD] 0.18), and 0.90 (SD 0.16) in the eye drops group. The difference was 0.01 (95% CI -0.01 to 0.03).
  • After 36 months, 74.2% (95% CI 69.3 to 78.6) of patients in the selective laser trabeculoplasty group didn’t need eye drops to keep their intraocular pressure at their target. Only 3% of the eye drops group were not using any drops at 36 months: 64.6% of the group were using one medication.
  • The groups had similar clinical outcomes at 36 months. There was little difference in visual acuity, intraocular pressure or visual field loss.
  • As expected, more people in the eye drops group had side effects from the drops, and more people in the selective laser trabeculoplasty group experienced transient events related to the procedure. Other adverse events were similar between the groups.
  • Selective laser trabeculoplasty used as a first-line treatment was cost-effective, with more quality-adjusted life years than eye drops and a lower cost. There was a 97% probability of laser being more cost-effective than eye drops at the usual NHS threshold.
  • This trial found an overall cost saving to the NHS of £451 per patient in specialist ophthalmology costs.

What does current guidance say on this issue?

NICE’s 2017 guideline on the diagnosis and management of glaucoma recommends treating ocular hypertension and open angle glaucoma with eyedrops (a generic prostaglandin analogue) in the first instance. For people with open angle glaucoma whose intraocular pressure is not sufficiently reduced with eyedrops, laser trabeculoplasty is one of three suggested next step alternatives.

This guideline updated and replaced NICE guideline CG85 (which was published in 2009). No fresh evidence about laser procedures was found when it was updated in 2017.

What are the implications?

About a third of people who are prescribed eye drops for glaucoma stop collecting their prescriptions within the first year. There are several reasons for this, including difficulty using the drops. Stopping treatment can lead to the progression of glaucoma. Offering an alternative to eye drops may reduce the chances of this happening.

This study shows that selective laser trabeculoplasty has benefit earlier in the treatment pathway than was previously thought. It appears to have all the advantages of being effective, safe, cost-effective compared to alternative uses of money, cost saving to clinics and also preferred by patients as first-line treatment.

This new evidence may inform changes to practice.

Citation and Funding

Gazzard G, Konstantakopoulou G, Garway-Heath E 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; Mar 9. doi: 10.1016/S0140-6736(18)32213-X. [Epub ahead of print].

This project was funded by the NIHR Health Technology Assessment Programme (project number 09/104/40) and was sponsored by the Moorfields Eye Hospital NHS Foundation Trust.



NHS website. Glaucoma. London: Department of Health and Social Care; 2018.

NICE. Glaucoma: diagnosis and management. NG81. London: National Institute for Health and Care Excellence; 2017.

Produced by the University of Southampton and Bazian on behalf of NIHR through the NIHR Dissemination Centre


  • Share via:
  • Print article


Expert commentary

This trial compared laser treatment against eyedrops in patients presenting with raised pressure in the eye with or without damage to the optic nerve structure/function (glaucoma).With a single laser treatment with minimal complications, the trial showed control of the eye pressure, and at three years, 74% of the laser patients did not require eye drop therapy.This study was the largest of its kind in the world, which will change clinical practice for patients with ocular hypertension or glaucoma and identified that a large number of them would benefit from early laser treatment. If fully implemented in the NHS and around the world, this treatment could potentially result in considerable savings and a more convenient treatment for patients.Professor Sir Peng T Khaw, Professor of Glaucoma and Ocular Healing, and Consultant Ophthalmic Surgeon; Director of the NIHR Biomedical Research Centre Moorfields Eye Hospital and UCL Institute of Ophthalmology; Eyes and Vision Programme Chair, UCL Partners Academic Health Science CentreThe commentator declares no conflicting interests 

Expert commentary

Standard initial treatment for newly diagnosed glaucoma and its common precursor, high eye pressure, consists of eye drops to lower the eye pressure.This randomised trial compared standard initial eye drop treatment with initial laser treatment. The study showed that initial laser resulted in better quality of life and less need for use of eye drops. Laser was also more cost effective.These findings strongly support the adoption of laser treatment as a first treatment option for people newly diagnosed with glaucoma or its precursor, high eye pressure. Commissioners and hospitals should now feel encouraged to collaboratively develop appropriate services for offering laser as a routine initial treatment option.Professor John Sparrow, Bristol Eye HospitalThe commentator was the Chair of the LiGHT trial independent steering committee 

Author commentary

The LiGHT trial results demonstrate excellent effectiveness and cost-effectiveness of selective laser trabeculoplasty in newly-diagnosed patients. The headline figures, however, are sensitive to the composition of the cohort studied. Over 80% of participants had ocular hypertension or mild glaucoma. Such patients require less intraocular pressure lowering than patients with more severe glaucoma and are less likely to need additional drops.Nevertheless, the overall drop burden is reduced with initial trabeculoplasty. Patients greatly value treatments which mitigate the need to take drops, so the trial outcome should result in a major shift in clinical practice. All newly-diagnosed patients (who are similar to those participating in the trial) should be offered the choice of laser trabeculoplasty or drops. Patient expectations should be managed in the context of the target intraocular pressure required.Professor David F Garway-Heath, IGA Professor of Ophthalmology, UCL Institute of Ophthalmology; Hon. Consultant Ophthalmologist, Moorfields Eye HospitalThe commentator is a co-author of the study 
Back to top