Laser-1st vs Drops-1st for Glaucoma and Ocular Hypertension (LIGHT)

Health-Related Quality of Life in Two Pathways for Newly Diagnosed Open Angle Glaucoma and Ocular Hypertension: an Unmasked, Multi-centre, Randomised Controlled Trial of Initial Selective Laser Trabeculoplasty Versus Medical Therapy

This is a randomized study with two treatment arms: 'initial Selective Laser Trabeculoplasty (SLT) followed by conventional medical therapy as required' ('Laser-1st') and 'medical therapy without laser ('Medicine-1st'). It compares quality of life in the two arms at three years, while also examining the incremental cost and cost-effectiveness of Laser-1st versus Medicine-1st.

Subjects are randomly allocated to one of two treatment arms that examine treatment pathways, rather than comparing single treatments alone: 'initial Selective Laser Trabeculoplasty (SLT) followed by conventional medical therapy as required' ('Laser-1st') and 'medical therapy without laser ('Medicine-1st'). We compare quality of life in the two pathways (arms) over three years, while also examining the incremental cost and cost-effectiveness of Laser-1st versus Medicine-1st. A 'Treat in Pursuit of Control' design (TPC) compares two different routes to a pre-defined target Intraocular pressure (IOP) (pathways). It is a pragmatic study that uses published guidelines to make the complex clinical treatment choices faced in managing glaucoma, standardised between treatment arms by use of computer treatment algorithms. A UK National Institute for Health and care Excellence (NICE)-compliant evidence-based IOP Treatment Target 1 is set for each patient, according to the study treatment algorithms. They then proceed through stepped increments of treatment intensity (up to and including surgery) until a predetermined Target IOP is reached. Target IOP is reassessed in the light of objective clinical evidence of stability of glaucomatous optic neuropathy (GON) and visual function using visual field tests and automated optic nerve evaluation. Health Related Quality of Life (HRQL) and secondary outcomes are compared for patients in each pathway.

Initial Selective Laser Trabeculoplasty (SLT) [PROCEDURE] followed by conventional medical therapy (eye-drops) as required. All participants in this arm start their treatment pathway with SLT. If this does not reach the predefined, patient-specific target IOP then repeat laser (once only) is given. If the IOP target is then not reached additional treatment with all standard medications may be used and ultimately surgery (trabeculectomy with mitomycin C) as needed.

Conventional medical therapy [DRUG] without laser. All participants in this arm start their treatment pathway medical treatment. If the IOP target is then not reached, additional treatment with all standard medications may be used and ultimately surgery (trabeculectomy with mitomycin C) as needed. During this pathway of treatment all commercially available medical treatments (eye-drops) are permitted according to a pre-specified step-wise intervention protocol described in detail in the publicly available trial protocol. This begins with prostaglandin analogues, then beta-blockers followed by alpha agonists or carbonic anhydrase inhibitors. The full range of available doses, treatments and drugs is beyond this short summary.

Primary Selective Laser Trabeculoplasty Treatment (followed by medications as required) Pathway. First treatment is SLT, 100 shots of laser over 360 degrees. If this does not reach the target IOP then repeat laser (once only) is given. If IOP not at target additional treatment with all standard medications may be used and ultimately surgery (trabeculectomy ). All available medical treatments (eye-drops) are permitted according to a pre-specified intervention protocol described in detail in the publicly available trial protocol. This begins with prostaglandin analogues, then beta-blockers followed by alpha agonists or carbonic anhydrase inhibitors. The full range of available doses, treatments and drugs is beyond this short summary.

Primary Medical Treatment Pathway (multiple medications, as required). If IOP not at target additional treatment with all standard medications may be used and ultimately surgery (trabeculectomy ). All available medical treatments (eye-drops) are permitted according to a pre-specified intervention protocol described in detail in the publicly available trial protocol. This begins with prostaglandin analogues, then beta-blockers followed by alpha agonists or carbonic anhydrase inhibitors. The full range of available doses, treatments and drugs is beyond this short summary.

Objective measures of treatment pathway efficacy, measured by number of hospital visits in two treatment arms over trial period.

Objective measures of treatment pathway efficacy, measured by number of medications used in two treatment arms over trial period.

Inclusion Criteria: Diagnosis of open angle glaucoma (defined as an open drainage angle and reproducible glaucomatous visual field defects as tested by the Swedish Interactive Threshold Algorithm (SITA) algorithm on the Humphrey Visual Field or glaucomatous optic neuropathy) OR Ocular hypertension (intra-ocular pressure above 21mmHg and requiring treatment as per National Institute of Health and Care Excellence (NICE) Guidelines). Able to provide informed consent. Exclusion Criteria: Advanced glaucoma in the potentially eligible eye as determined by Early Manifest Treatment Guidelines (EMGT) criteria 77: visual field loss mean deviation worse than -12dB in the better or -15dB in the worse eye. Secondary glaucoma (e.g. pigment dispersion syndrome, rubeosis, trauma etc) or any angle closure. Any contra-indication to selective laser trabeculoplasty (e.g. unable to sit at the laser-mounted slit-lamp; past history of uveitis). Unable to use topical medical therapy due to e.g. physical infirmity and a lack of carers able to administer daily eye-drops.

To supply, upon request and mutually agreed terms, IPD level anonymised data where permitted by local regulations and national law.

Vickerstaff V, Ambler G, Bunce C, Xing W, Gazzard G; LiGHT Trial Study Group. Statistical analysis plan for the Laser-1st versus Drops-1st for Glaucoma and Ocular Hypertension Trial (LiGHT): a multi-centre randomised controlled trial. Trials. 2015 Nov 11;16:517. doi: 10.1186/s13063-015-1047-9. Erratum In: Trials. 2017 Jul 11;18(1):318.

Gazzard G, Konstantakopoulou E, Garway-Heath D, Barton K, Wormald R, Morris S, Hunter R, Rubin G, Buszewicz M, Ambler G, Bunce C; LiGHT Trial Study Group. Laser in Glaucoma and Ocular Hypertension (LiGHT) trial. A multicentre, randomised controlled trial: design and methodology. Br J Ophthalmol. 2018 May;102(5):593-598. doi: 10.1136/bjophthalmol-2017-310877. Epub 2017 Sep 13. Erratum In: Br J Ophthalmol. 2021 Feb;105(2):e1.

Konstantakopoulou E, Gazzard G, Vickerstaff V, Jiang Y, Nathwani N, Hunter R, Ambler G, Bunce C; LiGHT Trial Study Group. The Laser in Glaucoma and Ocular Hypertension (LiGHT) trial. A multicentre randomised controlled trial: baseline patient characteristics. Br J Ophthalmol. 2018 May;102(5):599-603. doi: 10.1136/bjophthalmol-2017-310870. Epub 2017 Oct 5.

http://www.moorfields.nhs.uk/sites/default/files/LiGHT%20Trial%20Protocol%203.0%20-%2020-5-2015_3.pdf