Primary trabeculectomy versus primary glaucoma eye drops for newly diagnosed advanced glaucoma: TAGS RCT

Anthony J. King*, Gordon Fernie, Jemma Hudson, Ashleigh Kernohan, Augusto Azuara-Blanco, Jennifer Burr, Tara Homer, Hosein Shabaninejad, John M. Sparrow, David Garway-Heath, Keith Barton, John Norrie, Alison McDonald, Luke Vale, Graeme Maclennan

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

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Background: Patients diagnosed with advanced primary open-angle glaucoma are at a high risk of lifetime blindness. Uncertainty exists about whether primary medical management (glaucoma eye drops) or primary surgical treatment (augmented trabeculectomy) provide the best and safest  patient outcomes. Objectives: To compare primary medical management with primary surgical treatment (augmented trabeculectomy) in patients with primary open-angle glaucoma presenting with advanced disease in terms of health-related quality of life, clinical effectiveness, safety and cost-effectiveness. Design: This was a two-arm, parallel, multicentre, pragmatic randomised controlled trial. Setting: Secondary care eye services. Participants: Adult patients presenting with advanced primary open-angle glaucoma in at least one eye, as defined by the Hodapp–Parrish–Anderson classification of severe glaucoma. Intervention: Primary medical treatment – escalating medical management with glaucoma eye drops. Primary trabeculectomy treatment – trabeculectomy augmented with mitomycin C. Main outcome measures: The primary outcome was health-related quality of life measured with the Visual Function Questionnaire-25 at 2 years post randomisation. Secondary outcomes were mean intraocular pressure; EQ-5D-5L; Health Utilities Index 3; Glaucoma Utility Index; cost and cost-effectiveness; generic, vision-specific and disease-specific health-related quality of life; clinical effectiveness; and safety. Results: A total of 453 participants were recruited. The mean age of the participants was 67 years (standard deviation 12 years) in the trabeculectomy arm and 68 years (standard deviation 12 years) in the medicalmanagement arm.Over 65% of participants were male andmore than 80%were white. At 24 months, the mean difference in Visual Function Questionnaire-25 score was 1.06 (95% confidence interval –1.32 to 3.43; p = 0.383). There was no evidence of a difference between arms in the EQ-5D-5L score, the Health Utilities Index or the Glaucoma Utility Index. At 24 months, the mean intraocular pressure was 12.40 mmHg in the trabeculectomy arm and 15.07 mmHg in the medical management arm  (mean difference –2.75 mmHg, 95% confidence interval –3.84 to –1.66 mmHg; p < 0.001). Fewer types of glaucoma eye drops were required in the trabeculectomy arm. LogMAR visual acuity was slightly better in the medical management arm (mean difference 0.07, 95% confidence interval 0.02 to 0.11; p = 0.006) than in the trabeculectomy arm. There was no evidence of difference in safety between the two arms. A discrete choice experiment updated the utility values for the Glaucoma Utility Index. The within-trial economic analysis found a small increase in the mean EQ-5D-5L score (0.04) and that trabeculectomy has a higher probability of being cost-effective than medical management. The incremental cost of trabeculectomy per quality-adjusted life-year was £45,456. Therefore, at 2 years, surgery is unlikely to be considered cost-effective at a threshold of £20,000 per quality-adjusted life-year. When extrapolated over a patient’s lifetime in a model-based analysis, trabeculectomy, compared with  medical treatment, was associated with higher costs (average £2687), a larger number of quality-adjusted life-years (average 0.28) and higher incremental cost per quality-adjusted life-year gained (average £9679). The likelihood of trabeculectomy being cost-effective at a willingness-to-pay threshold of £20,000 per quality-adjusted life year gained was 73%. Conclusions: Our results suggested that there was no difference between treatment arms in healthrelated quality of life, as measured with the Visual Function Questionnaire-25 at 24 months. Intraocular pressure was better controlled in the trabeculectomy arm, and this may reduce visual field progression. Modelling over the patient’s lifetime suggests that trabeculectomy may be cost-effective over the range of values of society’s willingness to pay for a quality-adjusted life-year.

Original languageEnglish
Pages (from-to)i-158
Number of pages194
JournalHealth Technology Assessment
Issue number72
Publication statusPublished - Nov 2021

Bibliographical note

Funding Information:
Declared competing interests of authors: Anthony J King declares receiving honoraria payments from Thea Pharmaceutical (Keele, UK) and Allergan Pharmaceutical (Dublin, Ireland) for speaking at educational meetings. Augusto Azuara-Blanco declares membership of the National Institute for Health Research (NIHR) Health Technology Assessment (HTA) Prioritisation Committee B (2020–present). Jennifer Burr declares membership of the NIHR HTA Clinical Evaluations and Trials Committee (2010–14). David Garway-Heath reports grants from NIHR for the HTA programme 12/35/38 during the conduct of the study; personal fees from Aerie Pharmaceuticals (Bedminster, NJ, USA), Allergan Pharmaceuticals, Bausch & Lomb (Rochester, NY, USA), Omikron (Beirut, Lebanon) and OptoVue (Fremont, CA, USA); personal fees and non-financial support from Carl Zeiss Meditec (Jena, Germany) and CenterVue (Padova, Italy); grants from Pfizer Inc. (New York, NY, USA) and Alcon Research Institute (Geneva, Switzerland); grants and personal fees from Santen Pharmaceutical (Osaka, Japan); and research equipment from Heidelberg Engineering (Heidelberg, Germany) and Topcon (Tokyo, Japan) outside the submitted work. David Garway-Heath also declared membership of the NIHR HTA Clinical Evaluations and Trials Committee (2014–17). John Norrie reports grants from University of Aberdeen and University of Edinburgh during the conduct of the study; and reports being a past and present member of the following: HTA Commissioning Sub-Board (EOI), NIHR Clinical Trials Unit Standing Advisory Committee, NIHR HTA and Efficacy and Mechanism Evaluation (EME) Editorial Board, Pre-Exposure Prophylaxis Impact Review Panel, EME Strategy Advisory Committee, EME Funding Committee Members, EME Funding Committee Sub-Group Remit and Comp Check, HTA General Committee, HTA Funding Committee Policy Group (formerly CSG) and the HTA Commissioning Committee. John Norrie also reports the HTA Post-funding Committee Teleconference (2016–19) and Covid Reviewing 2020. Luke Vale reports grants from NIHR HTA programme 12/35/38 during the conduct of the study. Luke Vale was also a member of the NIHR HTA Clinical Trials and Evaluation Panel from 2014 to 2018. John M Sparrow reports grants from NIHR HTA programme 12/35/38 during the conduct of the study, and was the previous chairperson of the National Institute for Health and Care Excellence Glaucoma Guideline Committee guideline published in 2017. Keith Barton reports personal fees from Allergan Pharmaceuticals, Alcon Pharmaceuticals, Laboratoires Thea (Clermont-Ferrand, France), EyeTechCare (Rillieux-la-Pape, France), Glaukos (San Clemente, CA, USA), Kowa Pharmaceuticals (Montgomery, AL, USA), Ivantis Inc. (Irvine, CA, USA), pH Pharma (South San Francisco, CA, USA), iStar Medical (Wavre, Belgium), Radiance Therapeutics (Tucson, AZ, USA) and EyeD Pharma (Liège, Belgium), grants from Allergan and Laboratoires Thea, stock from Vision Medical Events Ltd (London, UK), International Glaucoma Surgery Registry (London, UK) and MedEther Ophthalmology (London, UK), and a patent from Advanced Ophthalmic Implants outside the submitted work.

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 72. See the NIHR Journals Library website for further project information.

The research reported in this issue of the journal was funded by the HTA programme as project number 12/35/38. The contractual start date was in January 2014. The draft report began editorial review in February 2020 and was accepted for publication in December 2020. The authors have been wholly responsible for all data collection, analysis and interpretation, and for writing up their work. The HTA editors and publisher have tried to ensure the accuracy of the authors’ report and would like to thank the reviewers for their constructive comments on the draft document. However, they do not accept liability for damages or losses arising from material published in this report.


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