Impact case study database

Although the effects of the COVID-19 pandemic and its associated measures on eye surgery have had a detrimental effect on the speed of EAGLE’s impact, much has already been achieved. This is important given that 76 million individuals are living with glaucoma and it has a global prevalence of 3.54% in people aged 40-80 years. Although primary open angle glaucoma (POAG) is the more prevalent type, primary angle closure glaucoma (PACG) - the condition studied in EAGLE - is more severe and more likely to cause irreversible blindness, has a profound impact on quality of life and places a high economic burden on individuals, health systems and society [S1]. PACG is most prevalent in East Asia but approximately 130,000 people are living with PACG in the UK, and it is more common in women with prevalence increasing with age. Implementation of EAGLE’s findings is made easier because the lens extraction procedure is already widely used for cataract surgery. It is the commonest surgical procedure performed in the western world, and one of the commonest operations in low- and middle-income countries (LMICs). As such, the necessary equipment and skills are available to allow the swift and straightforward change in management policy without additional training or capital expenditure.

The pragmatic nature of EAGLE and its inclusion of 30 sites in 5 countries with very different healthcare models and average income have been recognised as important features by commentators [S2], and helped demonstrate the generalisability of its findings and are facilitating their uptake. There has been substantial international interest in EAGLE with Professor Azuara-Blanco invited to present the findings at the World Glaucoma Congress and meetings of the European Glaucoma Society, UK and Ireland Glaucoma Society, Canadian Ophthalmological Society and German Ophthalmological Society. He was awarded the King James IV Professorship by the Royal College of Surgeons of Edinburgh in 2020 for his work on the EAGLE trial. The EAGLE findings were also welcomed by organisations such as the Glaucoma Research Foundation [S3] and, as noted in the President of the European Glaucoma Society’s Lancet commentary [S4] which accompanied the 2016 paper: ‘This is also the first prospective randomised therapeutic trial in ophthalmology in which one of the primary outcome measures is patient reported, through quality-of-life questionnaires. … This pragmatic trial is clinically relevant because it addresses a topic with widespread practical implications’. In 2019, a review article in Eye, the journal of the Royal College of Ophthalmologists concluded that the evidence from EAGLE that CLE was the superior treatment for both patient reported quality of life and IOP control indicates that CLE should be considered for first-line treatment of more advanced angle-closure disease, and that ‘[t]he EAGLE study has laid the foundations for CLE to be implemented into the UK’ [S5].

Impact on practice in East Asia

The evidence from EAGLE that CLE is superior for patient, clinical and economic outcomes, along with the absence of any serious safety issues with the procedure, provided compelling evidence to support a change in practice towards improved health outcomes for people with primary angle-closure glaucoma and has particular relevance to LMICs where access to chronic medical therapy for the management of glaucoma is often not possible, but the skill and facilities to undertake lens extraction is well developed. As a consequence, EAGLE’s findings have led to changes in national and international guidelines (see below) and had important impacts on practice in East Asia, where this condition is particularly prevalent. For example, following EAGLE, Professor Jelinar Mohamed Noor from the Ministry of Health in Malaysia said ‘ early lens removal is the current practice amongst us all who are with the Ministry of Health Malaysia’ and his colleague, Professor Jemaima Che hamzah, Head and Consultant Ophthalmologist at the Hospital Universiti Kebangsaan Malaysia noted ‘this practice is being used by most of my colleagues across Malaysia and Singapore’. Furthermore, in China, Professor Yuanbo Liang, professor and director of the Clinical and Epidemiological Eye Research Center, in Wenzhou Medical University said: ‘In our hospital, 60% of glaucoma patients had been treated with phaco, and Asia pacific cataract guideline has recommended phaco as a treatment method for PACG. Which means clear lens extract is an option for any PACG’ and ophthalmologists in Korea [S6] used the EAGLE results to note ‘these approaches [CLE] are likely to be effective for a public support health care system’.

Impact on practice in the UK

The importance of EAGLE to practitioners in the UK is emphasised by the fact it was one of only two trials that were specifically asked about in a survey of glaucoma specialists to inform the Royal College of Ophthalmologists’ latest guidelines. Among the 28 glaucoma experts who responded to this survey, 10 (36%) replied that the EAGLE results mean that they now routinely offer CLE to all patients with PACG and PAC with high IOP and a further 11 (39%) now consider CLE in some of these patients.

Impact on guidelines

EAGLE has influenced guidelines about the management of angle-closure glaucoma from the American Academy of Ophthalmology, the Royal College of Ophthalmologists and the European Glaucoma Society. All these guidelines, which were due to be published in 2020, were delayed by COVID-19 but their recommendations reflect the conclusions of EAGLE about CLE surgery being an important and acceptable alternative to laser PI. For example, a key feature of the new European Glaucoma Society guidelines is the change from the 4^th edition in 2014 [S7], which stated that the use of laser iridotomy as the initial procedure for patients with PACG ‘is justified in practically every case’ (page 112) to a new strong recommendation in the 5^th edition giving equal status to that technique and CLE based on the findings of EAGLE which is listed as one of landmark glaucoma trials (pages 26, 36 and 47) [S8]. These guidelines will be promoted across the European Glaucoma Society’s platforms, and their widespread dissemination is likely to exceed the 200,000 printed copies, over 100,000 downloads and translations into 12 languages of the 4^th edition. Furthermore, in keeping with the impact on practice in East Asia, local guidelines there now reflect the findings of EAGLE. For example, the glaucoma guidelines for Malaysia recommend that ‘early lens extraction may be considered as first-line treatment in primary angle closure and primary angle closure glaucoma’ (page 24) [S9].