Condition category
Eye Diseases
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Not provided at time of registration

Trial website

Contact information



Primary contact

Prof Augusto Azuara-Blanco


Contact details

The Eye Clinic
Aberdeen Royal Infirmary
AB25 2ZN
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number

EME 09/800/26 (as of 15/07/2010, previously MRC: G0701604)

Study information

Scientific title

The effectiveness of early lens extraction with intraocular lens implantation for the treatment of primary angle closure glaucoma: a randomised controlled trial (EAGLE)


EAGLE (Effectiveness, in Angle-closure Glaucoma of Lens Extraction)

Study hypothesis

In patients with primary angle closure glaucoma (PACG), this study will compare the clinical and cost-effectiveness of early lens extraction surgery compared with standard care (usually laser iridotomy followed by a sequence of medical therapy, laser iridoplasty and trabeculectomy).

Ethics approval

North of Scotland Research Ethics Committee 2, 09/10/2008, ref: 08/S0802/153

Study design

Multinational randomised controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Can be downloaded from


Primary angle closure glaucoma


The participants will be randomly allocate to the following treatments:
Intervention group: Early lens extraction with intraocular lens implantation
Control group: Standard care (usually laser iridotomy followed , as necessary, by a sequence of medical therapy, laser iridoplasty and trabeculectomy)

Total duration of follow-up: 3 years

Intervention type



Drug names

Primary outcome measure

1. Patient-centred outcome: Health Status, assessed by the EQ-5D at 6, 12, and 24 months with the major outcome assessment at 36 months from the date of randomisation
2. Clinical outcome: IOP at 3 year final assessment
3. Economic outcome: Incremental cost per quality adjusted life year (QALY) gained with QALYs based on the responses to the EQ-5D

Secondary outcome measures

The following will be assessed at 6, 12, and 24 months with the major outcome assessment at 36 months from the date of randomisation:

1. Patient-centred:
Patient reported, using:
1.1. A glaucoma specific utility instrument (GPI)
1.2. A vision specific health profile measure (NEI-VFQ25)

2. Clinical:
2.1. Need for trabeculectomy
2.2. Progressive visual field loss
2.3. Best-corrected visual acuity (ETDRS)
2.4. Extension of angle closure (degrees of appositional and synechial angle closure)
2.5. Escalation of therapy
2.6. Number of anti-glaucoma medications
2.7. Intolerance of medications
2.8. Incidence of acute attacks of angle closure

3. Economic:
Costs will be based on resource use data. Costs to the NHS and patients:
3.1. Use of health services for glaucoma related events or treatments
3.2. Patient costs (treatments, spectacles, travel to health services, sick leave)
3.3. Need for alternative management for glaucoma (e.g., surgery, drugs)
3.4. Other use of health services: visits to i) GP, ii) nurse, iii) optometrists

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Both males and females, age >=50 years
2. Diagnosis: either one of the following two types of patients: (i) primary angle-closure glaucoma (PACG), or (ii) primary angle-closure (PAC) with intraocular pressure (IOP) >30 mm Hg
3. Newly diagnosed, i.e. either (i) untreated or (ii) under medical treatment for 6 months or less
4. Angle closure (iridotrabecular contact) in 180 degrees or more
5. Patient must be phakic in the affected eye(s)
6. Written informed consent obtained

Participant type


Age group




Target number of participants

400 - The trial aims to recruit half of the participants in the UK (n = 200) and the other half in Hong Kong, Malaysia, Singapore and China combined (n = 200).

Participant exclusion criteria

1. Advanced glaucoma in the potentially eligible eye as determined by either: (i) visual field loss (mean deviation worse than -15dB) or (ii) cup-disc-ratio >0.9
2. Previously diagnosed acute angle closure attack in the potentially eligible eye
3. Increased surgical risk: e.g., corneal opacity, Fuch's endothelial dystrophy, pseudoexfoliation, previous vitreo-retinal surgery, not able to be positioned to undergo standard technique
4. Symptomatic cataract in either eye
5. Previous cataract surgery or laser iridotomy in study eye
6. Axial length <19 mm (nanophthalmos)
7. Secondary angle closure glaucoma
8. History of retinal ischaemia, macular oedema or wet age-related macular degeneration
9. Medically unfit for surgery or for completion of the trial

Removed from the protocol as of 04/11/10:
10. Life expectancy <3 years

Recruitment start date


Recruitment end date



Countries of recruitment

China, Hong Kong, Malaysia, Singapore, United Kingdom

Trial participating centre

Aberdeen Royal Infirmary
AB25 2ZN
United Kingdom

Sponsor information


NHS Grampian

Sponsor details

Research and Development Office
Foresterhill House Annexe
AB25 2ZB
United Kingdom

Sponsor type




University of Aberdeen

Sponsor details

Polwarth Building
AB25 2ZD
United Kingdom

Sponsor type




NHS Grampian

Sponsor details

Sponsor type

Not defined



Funder type

Research council

Funder name

Medical Research Council (MRC) (UK)

Alternative name(s)


Funding Body Type

government organisation

Funding Body Subtype

National government


United Kingdom

Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

2011 results in:
2016 results in:
2017 economic evaluation in:

Publication citations

  1. Results

    Azuara-Blanco A, Burr JM, Cochran C, Ramsay C, Vale L, Foster P, Friedman D, Quayyum Z, Lai J, Nolan W, Aung T, Chew P, McPherson G, McDonald A, Norrie J, , The effectiveness of early lens extraction with intraocular lens implantation for the treatment of primary angle-closure glaucoma (EAGLE): study protocol for a randomized controlled trial., Trials, 2011, 12, 133, doi: 10.1186/1745-6215-12-133.

Additional files

Editorial Notes

16/01/2017: Publication reference added. 07/10/2016: Publication reference added. 18/04/2013: The overall trial end date was changed from 31/01/2014 to 31/12/2014. 04/11/2010: Taiwan was removed and China and Malaysia were added to the countries of recruitment. EAGLE was also transferred from MRC to the Efficacy and Mechanism Evaluation (EME) programme for post-award management on the 15/07/2010.