Plain English Summary
Background and study aims
Amblyopia is reduced vision of one eye associated with a squint (misalignment of one eye) or anisometropia (one eye not in focus) occuring during the normal period of visual development (before 7 years of age). The mainstay treatment is full-time spectacle wear followed by patching of the good eye (covering the good eye with a patch like a plaster). The main objective of this study is to compare a personalised dosing strategy with a standardised dosing strategy of patching treatment for children with amblyopia.
Who can participate?
Participants need to be between 3 and 8 years of age with amblyopia associated with a squint and/or anisometropia.
What does the study involve?
There are three stages to the study. Firstly, an initial assessment will make sure that the patient's vision is stable and the diagnosis is correct. Secondly, those needing glasses will enter the 'refractive adaptation phase' and wear glasses full-time for 18 weeks. Thirdly, those who still have amblyopia after refractive adaptation will be randomly allocated to receive patching either with a personalised dosing strategy (PDS) or a standardised dosing strategy (SDS). Those prescribed the PDS will have their patient characteristics, age, type of amblyopia and severity of amblyopia entered into the PDS software and a prescribed duration of patching will be calculated. Those in the SDS group will be prescribed 2 hours a day of patching if they have mild amblyopia, 3 hours a day if they have moderate amblyopia and 5 hours a day if they have severe amblyopia. The actual duration of patching will be monitored using an occlusion dose monitor.
What are the possible benefits and risks of participanting?
The participants will have increased monitoring follow-up visits every 2 weeks. There are no side effects of the treatment.
Where is the study run from?
The study will be run at Princess Alexander Hospital, Harlow and Hillingdon NHS Trust (UK).
When is the study starting and how long is it expected to run for?
The study started recruiting in September 2013 and will continue recruiting until November 2014 and follow-up until mid 2015.
Who is funding the study?
National Institute of Health Research (UK).
Who is the main contact?
Dr Catherine Stewart
c.e.stewart@city.ac.uk
Trial website
Contact information
Type
Scientific
Primary contact
Dr Catherine Stewart
ORCID ID
Contact details
City Community and Health Sciences
10 Northampton Square
London
EC1V 0HB
United Kingdom
-
c.e.stewart@city.ac.uk
Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
15042
Study information
Scientific title
Randomised trial of a personalised dosing strategy versus a standardised dosing strategy for childhood amblyopia
Acronym
Study hypothesis
Amblyopia is the most common visual disorder of childhood in the Western world with an estimated prevalence of between 2-5%, accounting for approximately 90% of NHS Children's Eye Service. Most commonly, one eye is affected and the amblyopia - that is, a loss of vision - arises because of a squint (misalignment of the eyes) or anisometropia (two eyes focus differently). Amblyopia is considered treatable, and the importance of doing so has been highlighted by findings of an increased lifetime risk of blindness arising from disease or injury to the 'good eye' and statutory occupational exclusion.
However, it is acknowledged that amblyopia therapy (typically a patch over the good eye to promote function in the affected eye) is inefficient, and for most children the deficit is not fully corrected. Treatment regimens range from a few minutes a day to all waking hours and are decided mainly on an ad hoc rather than rational basis. These approaches all constitute 'standardised dosing strategies' (SDS) and do not accord with a growing realisation in medicine that treatment is best tailored to the individual: the so-called 'personalised dosing strategy' approach (PDS). Our proposed study seeks to evaluate the PDS approach by conducting a randomised trial comparing SDS with PDS in children with amblyopia aged 3 to 8 years. This study comprises three phases: 'initial assessment', 'refractive adaptation' and 'occlusion'. Children will be randomised to receive SDS or PDS occlusion once they have completed the refractive adaptation phase.
If a PDS approach were shown to be practical and potentially superior to the SDS approach it would be a highly significant advance in the management of the condition: the amount and duration of treatment could be minimised with clear benefits to the patient and with a potential gain in cost-effectiveness.
Hypothesis: a personalised dosing strategy provides superior visual outcome and a shorter treatment period than a standardised dosing strategy
More details can be found at: http://public.ukcrn.org.uk/search/StudyDetail.aspx?StudyID=15042
Ethics approval
Bloomsbury Ethics board, first MREC approval date 07/08/2013, 13/LO/0773
Study design
Randomised interventional treatment trial
Primary study design
Interventional
Secondary study design
Randomised controlled trial
Trial setting
GP practices
Trial type
Treatment
Patient information sheet
Not available in web format, please use the contact details below to request a patient information sheet
Condition
Topic: Eye, Generic Health Relevance and Cross Cutting Themes; Subtopic: Eye (all Subtopics), Generic Health Relevance (all Subtopics); Disease: Ophthalmology, Paediatrics
Intervention
Once participants enter the occlusion phases they are randomised to receive a Personalised Dosing Strategy (PDS) or a Standardised Dosing Strategy (SDS) of occlusion by patching. Those assigned PDS will have their patient characteristics, age, type of amblyopia and severity of amblyopia entered into the PDS software and their dose will be calculated. The actual dose recieved will be monitored using an occlusion dose monitor (a small data logger recording when patch is on and off the eye to the nearest second). Dosing will be modified at each follow-up visit depending on compliance with occlusion.
Those assigned the Standard Dosing Strategy will be prescribed 2 hours a day if they have mild, 3 hours if they have moderate and 5 hours a day if they have severe amblyopia. The occlusion they actually recieve will be monitored using an occlusion dose monitor.
Occlusion, Occlude eye by patching. Monitor dose worn with occlusion dosed monitor.
Refractive adaptation, Full-time glasses wear for 18 weeks monitored 6-weekly;
Follow Up Length: 12 month(s)
Intervention type
Other
Phase
Not Applicable
Drug names
Primary outcome measure
Visual acuity change; Timepoint(s): Change in visual acuity of the amblyopic eye during treatment
Secondary outcome measures
The secondary outcome measure will be stereoacuity measured using the Frisby test and the Randot pre-schooler test
Overall trial start date
01/09/2013
Overall trial end date
01/03/2015
Reason abandoned (if study stopped)
Eligibility
Participant inclusion criteria
1. The trial will recruit subjects with amblyopia associated with:
1.1. Strabismus
1.2. Anisometropia
1.3. A combination of anisometropia and strabismus
2. Children aged between 3 and 8 years with visual acuity of 0.2 logMAR or lower in the worst eye and an inter-ocular difference of at least 0.2 log units with the presence of anisometropia and/or strabismus and no other ocular pathology including amblyopia associated with form deprivation or previous occlusion treatment history will be eligible for recruitment.
3. Target Gender: Male & Female
Participant type
Patient
Age group
Child
Gender
Both
Target number of participants
Planned Sample Size: 120; UK Sample Size: 120
Participant exclusion criteria
1. Those with other ocular pathology
2. Those with form deprivation amblyopia as this is a minority group and often is linked with other ocular pathology
3. Previous history of treatment for amblyopia
4. Those with learning difficulties and therefore cannot perform an accurate visual acuity test on every occasion tested
Recruitment start date
01/09/2013
Recruitment end date
01/11/2014
Locations
Countries of recruitment
United Kingdom
Trial participating centre
City Community and Health Sciences
London
EC1V 0HB
United Kingdom
Funders
Funder type
Government
Funder name
NIHR Research for Patient Benefit (RfPB) (UK) Grant Codes: PB-PG-0808-16087
Alternative name(s)
Funding Body Type
Funding Body Subtype
Location
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
2015 protocol in: http://www.ncbi.nlm.nih.gov/pubmed/25906974