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. Amblyopia is usually treated with glasses wearing and by patching the better eye (wearing an eye patch). There is controversy whether a long period of glasses wearing before patching, called refractive adaptation, helps in treating children with amblyopia. The purpose of this study is to perform a trial to test whether refractive adaptation before patching improves the number of successfully treated children with amblyopia.
Who can participate?
Amblyopic children between 3 and 8 years of age.
What does the study involve?
Participants will be randomly allocated to two groups. Half of the participants will wear glasses for 18 weeks before patching for amblyopia is started, whereas the other half will wear the glasses for 3 weeks before patching.
What are the possible benefits and risks of participating?
The participants will receive information material for parents, teachers and children about amblyopia. Decorated patches will be given to children. Waiting time for appointments is likely to be shorter. It could be that the total treatment time is reduced. Possible occurrence of side effects will be very similar to the usual clinical treatment and could be rarely 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, Moorfields Eye Hospital, University of Graz, University of Heidelberg, Lead Centre: University of Leicester
When is the study starting and how long is it expected to run for?
The anticipated start date is June 2013 for a duration of 3 years; recruitment will be during the first 2.5 years of the study.
Who is funding the study?
Action Medical Research, UK
Who is the main contact?
Professor Irene Gottlob
The role of glasses wearing in amblyopia treatment: a randomised controlled multicentre trial
The number of children successfully treated after 720 hours of prescribed patching over 12 weeks is significantly higher following an initial period of 18 weeks glasses wearing period than 3 weeks glasses wearing period prior to patching therapy.
Derby NRES Committee EastMidlands, IRAS project ID:120878, approved 28 March 2013
Unmasked randomised controlled trial
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
Not available in web format, please use the contact details below to request a patient information sheet
There are two study arms:
Refractive Adaptation Group (n=173): A period of 18 weeks glasses wearing (i.e. RA) will be followed by a period of 24 weeks combined patching (10hrs/day, 6 days/week) and glasses wearing.
Early Patching Group (n=173): A period of 3 weeks glasses wearing will be followed by a period of 24 weeks combined patching (10hrs/day, 6 days/week) and glasses wearing.
Participants will have an initial full ophthalmologist examination including cycloplegic refraction and will be examined subsequently at 6 weekly intervals with visual acuity measurements.
Primary outcome measures
Number of children successfully treated after 720 hours of prescribed patching over 12 weeks following an initial period of either 3 weeks or 18 weeks glasses wearing prior to patching therapy.
Refractive Adaptation Group: A period of 18 weeks glasses wearing will be followed by a period of 24 weeks combined patching and glasses wearing. Examination will be every 6 weeks.
Early Patching Group: A period of 3 weeks glasses wearing will be followed by a period of 24 weeks combined patching (and glasses wearing. The first examination will be after 3 weeks and then every 6 weeks.
Secondary outcome measures
1. To compare the number of patients successfully resolved in ≤ 1080 hours of prescribed patching over 18 weeks, and in ≤ 1440 hours over 24 weeks. Where possible we will also compare the two groups in terms of final visual outcome, total duration of treatment and total amount of patching required.
2. To estimate the levels of compliance to glasses and patch wearing.
3. To explore the relationship between duration of glasses wearing and patching and improvement in vision.
4. To explore whether anisometropes respond better to RA compared to strabismus/mixed patients.
5. To explore whether electronic monitoring influences compliance and visual outcomes
6. Ascertain opinions from carers and children about the study treatment study through a questionnaire given during and on completion of the study.
Overall trial start date
Overall trial end date
Participant inclusion criteria
1. Children (aged 3 to 8 years) with newly detected amblyopia (difference of ≥ 0.3 LogMAR visual acuity between eyes)
2. A clinically significant refractive error (≥ 1.5D in at least 1 eye or 1D difference between the two eyes)
3. Able to perform the visual acuity test
Target number of participants
Participant exclusion criteria
1. Children without amblyopia as defined above or with amblyopia as defined above but with other ophthalmic or neurological diseases, or premature children
2. Bilateral amblyopia (vision of better eye corrected visual acuity > 0.2 LogMAR) is also an exclusion criterion.
Recruitment start date
Recruitment end date
Countries of recruitment
Austria, Germany, United Kingdom
Trial participating centre
Leicester Royal Infirmary
University of Leicester (UK)
College of Medicine
Biological Sciences and Psychology
Action Medical Research (UK)
Funding Body Type
private sector organisation
Funding Body Subtype
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
Results - basic reporting