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

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 medical management arm. Over 65% of participants were male and more 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;

CONCLUSIONS

Our results suggested that there was no difference between treatment arms in health-related 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.

FUTURE WORK

Further follow-up of participants will allow us to estimate the long-term differences of disease progression, patient experience and cost-effectiveness.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN56878850.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in

Glaucoma is an eye condition in which the intraocular pressure is too high, causing damage to the optic nerve and loss of vision. Patients with severe vision loss at diagnosis are the most at risk of blindness in their lifetime. Lowering pressure in the eye is the only way to prevent further vision loss. Two treatments to lower pressure are commonly used: using eye drops or having an operation known as a trabeculectomy. In England, Wales and Northern Ireland, the National Institute for Health and Care Excellence recommends surgery as the first treatment. However, we do not know which treatment is best for preventing vision loss or which is safest, has the best patient experience or provides the best value for money for the NHS. Therefore, surgery is not usually carried out in the first instance and patients start with eye drops instead. This study compared whether starting treatment with eye drops affected the quality of life of patients with advanced glaucoma more or less than starting treatment with trabeculectomy. We also investigated if initial treatment with surgery and initial treatment with eye drops were equally good at controlling pressure and were equally safe, and how much each treatment cost the NHS. Every patient had an equal chance of starting treatment with surgery or eye drops and they participated in the study for 2 years. We found that quality of life was similar regardless of treatment. Those starting with surgery had lower pressure and needed far fewer types of eye drops than those starting with eye drops. Thirty-nine patients in the eye drop arm required surgery to control their glaucoma. Initial treatment with eye drops was cheaper over 2 years’ follow-up. Our study suggests that, over a 2-year period, having surgery in the first instance lowers intraocular pressure more than eye drops and is equally as safe as eye drops. Although eye drops are a cheaper treatment option for the NHS, if the effects of surgery on intraocular pressure are lasting, then the increased cost may be justified.