Strabismic AmblyopiaAMPELNCT02555384
AMblyopia Treatment Through PErceptual Training in Children (AMPEL)
A study testing crowded drawing task and uncrowded drawing task in people with Strabismic Amblyopia, run by University of Basel.
Trial summary
Amblyopia, affects 4% of the population. In the presence of a normal retina and optic nerve, the visual cortex does not develop normally secondary to the amblyopic eye being at a disadvantage in the sensitive period such as in strabismus. Read more about this study
- Who is it for?
- Ages 4 to 8 years
- Conditions the study is for
- Strabismic Amblyopia
- What is being tested?
- crowded drawing task and uncrowded drawing task
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 0 participants
- Where
- No sites listed yet
- Study dates
- Jan 2020to 30 Nov 2020
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 4 to 8 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- strabismic amblyopia
- cycloplegic refraction corrected at least 3 months prior to enrolment
- Reliable test results for two previous examinations
- absence of ocular conditions other than strabismus, amblyopia and corrected refractive error
Who cannot join
- inability to perform reliably when examined
- inability to draw
- unstable visual results on 2 previous examinations
About this study
Official title: Improving Visual Functions in Young Children With Amblyopia Through Perceptual Learning
Amblyopia, affects 4% of the population. In the presence of a normal retina and optic nerve, the visual cortex does not develop normally secondary to the amblyopic eye being at a disadvantage in the sensitive period such as in strabismus. Amblyopia is associated with visuospatial disorders, and poor to absent stereopsis. Amblyopia is treated by occlusion of the non- amblyopic eye in childhood. The present study aims to evaluate the effectiveness of perceptual learning (PL), that is a training of visual drawing tasks (12 sessions of 30 Minutes duration) with crowding (c) for children with amblyopia compared to an amblyopic control group with a placebo drawing task.
Arm 1: Crowded (PLc)- Training with small spacing Arm 2: Uncrowded (PLu)- Training with large spacing Prior to this, a small group will help optimize parameters such as contrast and distance of visual objects presented
Read the detailed description
Outcome(s):
Primary endpoints: improvement of amblyopia,crowding ratio (CR) and visual acuity before and after training, at 7 weeks, at 6 months Secondary outcome: hand-eye coordination, evaluated with the Beery VMI test before and after training, at 7 weeks, at 6 months Tertiary outcome over 6 years of age: macular structure measured with the OCT before and after training, at 7 weeks, at 6 months
Study design:
Cohort study, randomised controlled trial, single blind, active control, parallel groups
Inclusion / Exclusion criteria:
- 20 Children included to optimize test criteria (high vs low contrast and spacing).
- 40 Children for 2-armed study.
Measurements and procedures:
12 sessions (2x per week for 6 weeks, 30 Minutes each) where drawing tasks are performed during their occlusion time.
Arm 1: Crowded - task with small spacing Arm 2: Uncrowded task with large spacing. Prior to this, a small group will help optimize parameters such as contrast and distance of visual objects presented The following parameters are evaluated at onset, at week 7 and at 6 months: visual acuity with and without crowding, the Berry Test and in children over 6 years of age, if possible: a reading task and OCT.
Statistical Considerations:
Patients will be randomized by letting a computer program perform the assignment of children in a certain training group. However, some restrictions will be inserted on the amount of randomization: equal number of children in our training groups, age- and acuity matched groups, equal patching times.
The analysis is aimed at answering the primary question: Can the training reduce crowding and improve visual acuity in children with amblyopia? In order to answer this question, a repeated measures ANOVA is conducted in which the crowding ratio (CR) before and after training will be entered as a within-subjects variable (2 levels: CR pre, and CR post/VA pre, VA post). Training group will be entered as a between subjects variable (2 levels: control and experimental). If there is an interaction effect, post hoc ANOVA's will be conducted to disentangle the effect of training on the CR within training groups.
A secondary question is: Can the training improve hand-eye coordination in children with amblyopia. To this regard the results of the Beery VMI test are being evaluated with a repeated measures ANOVA.
Sample size Calculation. As the crowding ratio (CR) is to be expected more important than VA, only this parameter will be powered.
Main parameter for the power calculation will be the difference (CRd) of the CR at the end of the intervention period compared to the CR at screening.
A CR decrease of 0.3 between "control" and "learning" group is assumed to be of clinical relevance.
The population standard deviation (SD) of CR is assumed to be 0.33. Assuming a moderate correlation coefficient of 0.5 between timepoints, the within subject SD is calculated as sqrt(0.33*0.33*0.5)=0.23. Therefore the SD of CRd is sqrt(2)*0.23=0.33. [Details are described in Sample Sizes for Clinical Trials,Steven A . Julious,Chapman and Hall/CRC 2009].
Based on a sample size of 20 subjects for each study group, there is a power of 88% to detect a CRd decrease of 0.3. This calculation is based on a one-sided T-test (alpha=5%).
GCP Statement: This study will be conducted in compliance with the protocol, the current version of the Declaration of Helsinki, the ICH-GCP or ISO EN 14155 (as far as applicable) as well as all national legal and regulatory requirements.
- Conditions
- Strabismic Amblyopia
- Being tested
- crowded drawing task, uncrowded drawing task
- Medical subject headings
- Amblyopia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
crowded drawing taskOther
Marking inverted signs on a sheet where symbols are presented close to one another
uncrowded drawing taskOther
Marking inverted signs on a sheet where there is a larger distance between symbols
| Study group | Role | What they receive |
|---|---|---|
| crowded drawing task | Active comparator | children will be asked to draw on a pattern presented under crowded viewing conditions. Receives: Other: crowded drawing task |
| uncrowded drawing task | Placebo comparator | children will be asked to draw on a pattern presented under uncrowded viewing conditions Receives: Other: uncrowded drawing task |
What is being measured
The primary outcome is the main question the study is designed to answer.
Crowding Ratio (CR)
CR= Ratio of crowded versus uncrowded visual acuity. This is compared pre to post treatment
Measured: 7 weeks
Secondary outcomes (1)
hand-eye coordination
Outcome of a Beery test
Measured: 7 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Sep 2015 (estimated)
- Study startJan 2020 (estimated)
- Primary completion30 Nov 2020
- Study completion30 Nov 2020
Why it stopped: Inclusion and Exclusion criteria too stringent, no patient coluld be recruited
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Strabismic AmblyopiaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 0 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Basel
- Sponsor type
- University, hospital or other
- Collaborators
- University Medical Center Nijmegen
- Responsible party
- Principal investigator, Anja Palmowski-Wolfe, University of Basel
- Investigators
- Anja M Palmowski-Wolfe, Prof. med., Principal investigator, University Basel, Eye Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02555384
- Sponsor's protocol ID
- EKNZ2015-264
- Acronym
- AMPEL
- Status last verified
- Jun 2023
- First submitted
- 16 Sep 2015
- Last updated
- 23 Jun 2023
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Huurneman B, Boonstra FN, Cox RF, van Rens G, Cillessen AH. Perceptual learning in children with visual impairment improves near visual acuity. Invest Ophthalmol Vis Sci. 2013 Sep 17;54(9):6208-16. doi: 10.1167/iovs.13-12220.
PubMed 23950157
Study at a glance
From the registry record, last updated by the sponsor on 23 Jun 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Improving Visual Functions in Young Children With Amblyopia Through Perceptual Learning
- ClinicalTrials.gov ID
- NCT02555384
- Acronym / sponsor ID
- AMPEL / EKNZ2015-264
- Conditions
- Strabismic Amblyopia
- Study type
- Interventional
- Recruitment status
- WithdrawnReason stopped: Inclusion and Exclusion criteria too stringent, no patient coluld be recruited
- Enrolment
- 0 participants (actual)
- Lead sponsor
- University of BaselUniversity, hospital or other
- Collaborators
- University Medical Center Nijmegen
- Study start
- Jan 2020 (estimated)
- Primary completion
- 30 Nov 2020 (actual)
- Study completion
- 30 Nov 2020 (actual)
- First posted
- 21 Sep 2015 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Amblyopia, affects 4% of the population. In the presence of a normal retina and optic nerve, the visual cortex does not develop normally secondary to the amblyopic eye being at a disadvantage in the sensitive period such as in strabismus. Amblyopia is associated with visuospatial disorders, and poor to absent stereopsis. Amblyopia is treated by occlusion of the non- amblyopic eye in childhood. The present study aims to evaluate the effectiveness of perceptual learning (PL), that is a training of visual drawing tasks (12 sessions of 30 Minutes duration) with crowding (c) for children with amblyopia compared to an amblyopic control group with a placebo drawing task.
Arm 1: Crowded (PLc)- Training with small spacing Arm 2: Uncrowded (PLu)- Training with large spacing Prior to this, a small group will help optimize parameters such as contrast and distance of visual objects presented
Detailed description
Outcome(s):
Primary endpoints: improvement of amblyopia,crowding ratio (CR) and visual acuity before and after training, at 7 weeks, at 6 months Secondary outcome: hand-eye coordination, evaluated with the Beery VMI test before and after training, at 7 weeks, at 6 months Tertiary outcome over 6 years of age: macular structure measured with the OCT before and after training, at 7 weeks, at 6 months
Study design:
Cohort study, randomised controlled trial, single blind, active control, parallel groups
Inclusion / Exclusion criteria:
- 20 Children included to optimize test criteria (high vs low contrast and spacing).
- 40 Children for 2-armed study.
Measurements and procedures:
12 sessions (2x per week for 6 weeks, 30 Minutes each) where drawing tasks are performed during their occlusion time.
Arm 1: Crowded - task with small spacing Arm 2: Uncrowded task with large spacing. Prior to this, a small group will help optimize parameters such as contrast and distance of visual objects presented The following parameters are evaluated at onset, at week 7 and at 6 months: visual acuity with and without crowding, the Berry Test and in children over 6 years of age, if possible: a reading task and OCT.
Statistical Considerations:
Patients will be randomized by letting a computer program perform the assignment of children in a certain training group. However, some restrictions will be inserted on the amount of randomization: equal number of children in our training groups, age- and acuity matched groups, equal patching times.
The analysis is aimed at answering the primary question: Can the training reduce crowding and improve visual acuity in children with amblyopia? In order to answer this question, a repeated measures ANOVA is conducted in which the crowding ratio (CR) before and after training will be entered as a within-subjects variable (2 levels: CR pre, and CR post/VA pre, VA post). Training group will be entered as a between subjects variable (2 levels: control and experimental). If there is an interaction effect, post hoc ANOVA's will be conducted to disentangle the effect of training on the CR within training groups.
A secondary question is: Can the training improve hand-eye coordination in children with amblyopia. To this regard the results of the Beery VMI test are being evaluated with a repeated measures ANOVA.
Sample size Calculation. As the crowding ratio (CR) is to be expected more important than VA, only this parameter will be powered.
Main parameter for the power calculation will be the difference (CRd) of the CR at the end of the intervention period compared to the CR at screening.
A CR decrease of 0.3 between "control" and "learning" group is assumed to be of clinical relevance.
The population standard deviation (SD) of CR is assumed to be 0.33. Assuming a moderate correlation coefficient of 0.5 between timepoints, the within subject SD is calculated as sqrt(0.33*0.33*0.5)=0.23. Therefore the SD of CRd is sqrt(2)*0.23=0.33. [Details are described in Sample Sizes for Clinical Trials,Steven A . Julious,Chapman and Hall/CRC 2009].
Based on a sample size of 20 subjects for each study group, there is a power of 88% to detect a CRd decrease of 0.3. This calculation is based on a one-sided T-test (alpha=5%).
GCP Statement: This study will be conducted in compliance with the protocol, the current version of the Declaration of Helsinki, the ICH-GCP or ISO EN 14155 (as far as applicable) as well as all national legal and regulatory requirements.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| crowded drawing task | Active comparator | Other: crowded drawing taskchildren will be asked to draw on a pattern presented under crowded viewing conditions. |
| uncrowded drawing task | Placebo comparator | Other: uncrowded drawing taskchildren will be asked to draw on a pattern presented under uncrowded viewing conditions |
Who may qualify
- Ages
- 4 to 8 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (4 listed)
- strabismic amblyopia
- cycloplegic refraction corrected at least 3 months prior to enrolment
- Reliable test results for two previous examinations
- absence of ocular conditions other than strabismus, amblyopia and corrected refractive error
Key exclusion criteria (3 listed)
- inability to perform reliably when examined
- inability to draw
- unstable visual results on 2 previous examinations
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| crowded drawing taskMarking inverted signs on a sheet where symbols are presented close to one another | Other | crowded drawing task |
| uncrowded drawing taskMarking inverted signs on a sheet where there is a larger distance between symbols | Other | uncrowded drawing task |
Primary outcome
Crowding Ratio (CR)
Time frame: 7 weeks
CR= Ratio of crowded versus uncrowded visual acuity. This is compared pre to post treatment
1 secondary outcome
hand-eye coordination
Time frame: 7 weeks
Results and safety
The study was withdrawn before enrolling participants, so there are no results.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Jun 2023.
- Background: PubMed 23950157Huurneman B, Boonstra FN, Cox RF, van Rens G, Cillessen AH. Perceptual learning in children with visual impairment improves near visual acuity. Invest Ophthalmol Vis Sci. 2013 Sep 17;54(9):6208-16. doi: 10.1167/iovs.13-12220.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Anja M Palmowski-Wolfe, Prof. med. principal investigator
University Basel, Eye Hospital
Questions about this trial
What is this clinical trial studying?
A study testing crowded drawing task and uncrowded drawing task in people with Strabismic Amblyopia, run by University of Basel.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: withdrawn, as of the sponsor's last update on 23 Jun 2023. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study was withdrawn before enrolling participants, so there are no results.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Crowding Ratio (CR) (time frame: 7 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT02555384, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Jun 2023.