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

Plain English Summary

Background and study aims
Amblyopia (also called lazy eye) is the most common disease affecting vision in childhood. Currently 30% of children treated for amblyopia do not reach normal vision after a year or more of treatment. Poor adherence to patching (wearing an eye patch) and glasses wearing has been identified as a potential contributing factor for this problem. Electronic monitors have been used in various studies. However, at present none of these studies have provided feedback to parents about the results of the measurements. In other diseases feedback about compliance to treatment has been shown to be of benefit. For example, it has been shown that feedback to parents and patients about the frequency of use of steroid inhalers can significantly increase adherence to the daily use of inhaled steroids in children with asthma. The aim of this study will be to investigate whether giving feedback to families about the amount of spectacle and patch wear can improve adherence and in turn the outcome of amblyopia therapy.

Who can participate?
Amblyopic children aged between 2 and 8 years.

What does the study involve?
Children will be randomly allocated to one of two groups: the feedback group and the control group. Both groups will be asked to wear their glasses full time and to patch (10 hours/day, 6 days/week) during a 12-week period. Patients will be examined every 3 weeks. Patients within the feedback group will be given feedback from information provided by the monitors.

What are the possible benefits and risks of participating?
There may be no direct benefit to the patient; however, we anticipate that patients in the study will have shorter waiting times and will be seen more often than the comparative NHS treatment, leading to the possible total treatment time being reduced. The study is likely to have only minimal risk with possible occurrence of side effects similar to the usual clinical treatment, including increase of squint, double vision or reduced vision in the better eye (which is almost always reversible).

Where is the study run from?
University of Leicester (UK).

When is the study starting and how long is it expected to run for?
The study is expected to start in September 2013 and run for about 2 years; recruitment will be during the first 1.5 years of the study.

Who is funding the study?
National Eye Research Centre (NERC), UK

Who is the main contact?
Professor Irene Gottlob

Trial website

Contact information



Primary contact

Prof Irene Gottlob


Contact details

University of Leicester
School of Medicine
Department of Cardiovascular Sciences
Ophthalmology Group
Robert Kilpatrick Clinical Sciences Building P O Box 65
Leicester Royal Infirmary
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number

Version 1

Study information

Scientific title

The effect of feedback to adherence to glasses and patch wear in amblyopia treatment: a randomised clinical trial



Study hypothesis

The adherence to amblyopia treatment in children receiving feedback about the level of adherence to patching after 720 hours of prescribed patching over 12 weeks will be significantly higher than those who do not receive feedback.

Ethics approval

NRES Committee East Midlands - Derby, 15/08/2013, ref: 13/EM/0285

Study design

Unmasked randomised controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet




There will be two treatment arms:
A. Feedback Group: A period of 12 weeks of full-time glasses wearing and patching (10 hrs/day, 6 days/week) followed by feedback on hours of glasses and patch wear at each examination (n=51).
B. Control Group: A period of 12 weeks of full-time glasses wearing and patching (10 hrs/day, 6 days/week) without feedback on hours of glasses and patch wear at each examination (n=51).
The total time the patients will be in the trial is 12 weeks.

Intervention type



Not Applicable

Drug names

Primary outcome measure

Adherence is determined as the the number of hours patched patching over 12 weeks.

Secondary outcome measures

1. Number of hours of glasses wear over the 12 week period.
2. Visual outcome using the formula described by Stewart et al. (% deficit corrected) over the 12 week period

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Children (age range is between 2-8 years inclusive) with monocular amblyopia (difference of ≥ 0.3 logMAR visual acuity between eyes) due to anisometropia (≥ 1.5D in at least one eye or 1D difference between the two eyes), strabismus or both
2. Previous patching ≤ 18 months

Participant type


Age group




Target number of participants


Participant exclusion criteria

Children with other ophthalmic or neurological diseases, bilateral amblyopia or premature children.

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

University of Leicester
United Kingdom

Sponsor information


University of Leicester (UK)

Sponsor details

College of Medicine
Biological Sciences and Psychology
Level 4
United Kingdom

Sponsor type




Funder type


Funder name

National Eye Research Centre (NERC) (UK)

Alternative name(s)


Funding Body Type

private sector organisation

Funding Body Subtype

Universities (academic only)


United Kingdom

Results and Publications

Publication and dissemination plan

Planned publication in a high-impact peer reviewed journal.

IPD sharing statement:
The data sharing plans for the current study are unknown and will be made available at a later date.

Intention to publish date


Participant level data

To be made available at a later date

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

11/06/2020: The intention to publish date has been changed from 01/12/2019 to 01/12/2020. 15/01/2018: The overall trial end date has been updated from 01/04/2018 to 31/12/2018. Added the publication and dissemination sharing plans and the participant level data sharing statement. 02/09/2016: The overall trial dates have been updated from 02/09/2013 - 01/09/2015 to 15/08/2013 - 01/04/2018 and the recruitment dates have been updated from 02/09/2013 - 01/03/2015 to 01/10/2013 - 31/12/2017.