AmblyopiaNCT02458846
Efficacy of Visual Screening in Ontario
A study testing Crowded HOTV Acuity Test, Preschool Randot Stereoacuity Test and Plusoptix Autorefractor in people with Amblyopia, run by The Hospital for Sick Children at 1 site in Canada.
Trial summary
Amblyopia (lazy eye), is the leading treatable cause of vision loss in childhood. Uncorrected refractive errors (ie farsightedness) can lead to difficulties in school. Unfortunately, many children do not receive vision screening until they have already developed irreversible vision problems. Read more about this study
- Who is it for?
- Ages 3 to 8 yearsHealthy volunteers can take part
- Conditions the study is for
- Amblyopia
- What is being tested?
- Crowded HOTV Acuity Test, Preschool Randot Stereoacuity Test and Plusoptix Autorefractor
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 2,597 participants
- Where
- 1 siteCanada
- Study dates
- Sep 2014to 15 Dec 2019
- 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 3 to 8 years
- All sexes
- Healthy volunteers accepted
- Child
Who may be able to join
- Screening: children enrolled in senior kindergarten (age 5-6 years)
- Follow-up: children enrolled in Grade 2 (age 7-8 years)
Who cannot join
- None
Trial locations and contacts
1 site in 1 country.
About this study
Official title: The Efficacy of a Visual Screening Program to Reduce Later Amblyopia and Untreated Refractive Errors
Amblyopia (lazy eye), is the leading treatable cause of vision loss in childhood. Uncorrected refractive errors (ie farsightedness) can lead to difficulties in school. Unfortunately, many children do not receive vision screening until they have already developed irreversible vision problems. We will conduct a cluster randomized clinical trial in which schools, not individual children, are randomly allocated to receive a kindergarten visual screening program or to receive no intervention by the research team (i.e., "care as usual"). We will compare the prevalence of visual problems (and proportion of children with reading problems) when the children are in Grade 2, after allowing for at least one year of treatment.
Read the detailed description
The proposed study is a single-masked cluster randomized clinical trial, with randomization and analyses occurring at the level of "schools" (i.e., we are not randomly assigning individuals to groups). To assess the efficacy of a visual screening program, we will compare visual outcomes in 25 schools randomly chosen to receive the program and 25 schools allocated to "care as usual" one year after screening. The screening tools are HOTV crowded acuity, Preschool Randot Stereoacuity Test, and Plusoptix Autorefractor. The outcome measures will assess later differences between schools receiving the visual screening program and control schools for prevalence of (1) visual and (2) reading problems. A lower prevalence of either or both problems in schools where the visual screening program was offered would provide evidence for the efficacy of vision screening. Primary outcome measure is the prevalence of amblyopia, reduced stereo vision, and untreated clinically significant refractive errors in "screened" versus "care as usual" schools. Secondary outcome measure is the proportion of children performing 1 standard deviation below average on reading scores in "screened" versus "care as usual" schools.
- Conditions
- Amblyopia
- Being tested
- Crowded HOTV Acuity Test, Preschool Randot Stereoacuity Test, Plusoptix Autorefractor, Comprehensive Eye Exam
- Medical subject headings
- Amblyopia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Crowded HOTV Acuity TestOther
This is one of the most sensitive tests of acuity for vision screening of young children. The child is asked to recognize a letter (H,O,T,V) that is surrounded by bars to induce the crowding effects typical of amblyopia. Children were tested monocularly and was required to achieve at least 20/32 in each eye to pass. Children already wearing glasses were tested with their glasses on.
Preschool Randot Stereoacuity TestOther
This is a reliable screening test for stereo depth perception for young children. Children wear polarized stereoglasses and are asked to identify or match shapes that are "hiding in the snow", which cannot be perceived if the child has abnormal binocular vision. Children were required to achieve at least 60 arcseconds of disparity to pass. Children already wearing glasses were tested with their glasses worn under the stereo glasses.
Plusoptix AutorefractorDevice
Autorefractors are electronic devices that measure refractive errors by focusing a light onto the child's eyes and recording how their reflections from the retina return to the camera. The Plusoptix has been shown to have high sensitivity and specificity in previous research. AAPOS (2013) guidelines were used to determine the referral criteria.
Comprehensive Eye ExamOther
Children who did not pass all three screening tests were referred for full cycloplegic optometry exams, with a parent/guardian present. Optometrists assessed visual history, monocular visual acuity (near \& far), strabismus, binocular function, abnormalities of the anterior segment, and cycloplegic refraction. If the optometrist prescribed glasses, frames were chosen at the time of the exam and the glasses were dispensed either at school (with an optician) or at the optometrist's office.
| Study group | Role | What they receive |
|---|---|---|
| Screened Schools | Experimental | 25 schools. Screening involved: crowded HOTV acuity test, Preschool Randot Stereoacuity Test, and Plusoptix autorefractor. Referral criteria followed AAPOS guidelines for screening for amblyopia and amblyopia risk factors. Children who fail any one of the three tests (including uncooperative/unable children) will be given a referral letter, which includes an assigned appointment time for a comprehensive eye exam at school with a licensed optometrist. Any needed glasses will be dispensed at no cost to the parents. 6 months after the eye exam, we will follow up with a phone call to parents to offer any additional support (such as replacing broken/lost glasses) Receives: Other: Crowded HOTV Acuity Test; Other: Preschool Randot Stereoacuity Test; Device: Plusoptix Autorefractor; Other: Comprehensive Eye Exam |
| Care As Usual Schools | No intervention | 25 schools were randomly allocated to the "care as usual" schools. No intervention was provided by the research team, however, children may have received optometry/ophthalmology care via regular referral channels (e.g., family physicians, teachers) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Prevalence of amblyopia
Prevalence of suspected amblyopia, defined as 2-or-greater line difference in acuity between eyes
Measured: 16 months
Prevalence of refractive errors
Untreated clinically significant refractive errors defined by AAPOS (2013) guidelines
Measured: 16 months
Prevalence of reduced stereo vision
Stereoacuity is often reduced in patients with some types of amblyopia, and will defined as worse than 30 arcsec
Measured: 16 months
Secondary outcomes (2)
Proportion of below-average readers Year 1
Proportion of Grade 1 children reading 1 SD below average
Measured: 10 months
Proportion of below-average readers Year 2
Proportion of Grade 2 children reading 1 SD below average
Measured: 22 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Jun 2015 (estimated)
- Study startSep 2014
- Primary completion15 Dec 2019
- Study completion15 Dec 2019
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for 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
- Diagnosis
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 2,597 participants (actual)
Sponsor and investigators
- Lead sponsor
- The Hospital for Sick Children
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Agnes Wong, The Hospital for Sick Children
- Investigators
- Agnes Wong, Principal investigator, The Hospital for Sick Children
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02458846
- Sponsor's protocol ID
- 1000045972
- Status last verified
- Mar 2020
- First submitted
- 8 Jan 2015
- Last updated
- 19 Mar 2020
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 19 Mar 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Efficacy of a Visual Screening Program to Reduce Later Amblyopia and Untreated Refractive Errors
- ClinicalTrials.gov ID
- NCT02458846
- Acronym / sponsor ID
- 1000045972
- Conditions
- Amblyopia
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 2,597 participants (actual)
- Lead sponsor
- The Hospital for Sick ChildrenUniversity, hospital or other
- Study start
- Sep 2014
- Primary completion
- 15 Dec 2019 (actual)
- Study completion
- 15 Dec 2019 (actual)
- First posted
- 1 Jun 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 (lazy eye), is the leading treatable cause of vision loss in childhood. Uncorrected refractive errors (ie farsightedness) can lead to difficulties in school. Unfortunately, many children do not receive vision screening until they have already developed irreversible vision problems. We will conduct a cluster randomized clinical trial in which schools, not individual children, are randomly allocated to receive a kindergarten visual screening program or to receive no intervention by the research team (i.e., "care as usual"). We will compare the prevalence of visual problems (and proportion of children with reading problems) when the children are in Grade 2, after allowing for at least one year of treatment.
Detailed description
The proposed study is a single-masked cluster randomized clinical trial, with randomization and analyses occurring at the level of "schools" (i.e., we are not randomly assigning individuals to groups). To assess the efficacy of a visual screening program, we will compare visual outcomes in 25 schools randomly chosen to receive the program and 25 schools allocated to "care as usual" one year after screening. The screening tools are HOTV crowded acuity, Preschool Randot Stereoacuity Test, and Plusoptix Autorefractor. The outcome measures will assess later differences between schools receiving the visual screening program and control schools for prevalence of (1) visual and (2) reading problems. A lower prevalence of either or both problems in schools where the visual screening program was offered would provide evidence for the efficacy of vision screening. Primary outcome measure is the prevalence of amblyopia, reduced stereo vision, and untreated clinically significant refractive errors in "screened" versus "care as usual" schools. Secondary outcome measure is the proportion of children performing 1 standard deviation below average on reading scores in "screened" versus "care as usual" schools.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Screened Schools | Experimental | Other: Crowded HOTV Acuity Test, Other: Preschool Randot Stereoacuity Test, Device: Plusoptix Autorefractor, Other: Comprehensive Eye Exam25 schools. Screening involved: crowded HOTV acuity test, Preschool Randot Stereoacuity Test, and Plusoptix autorefractor. Referral criteria followed AAPOS guidelines for screening for amblyopia and amblyopia risk factors. Children who fail any one of the three tests (including uncooperative/unable children) will be given a referral letter, which includes an assigned appointment time for a comprehensive eye exam at school with a licensed optometrist. Any needed glasses will be dispensed at no cost to the parents. 6 months after the eye exam, we will follow up with a phone call to parents to offer any additional support (such as replacing broken/lost glasses) |
| Care As Usual Schools | No intervention | –25 schools were randomly allocated to the "care as usual" schools. No intervention was provided by the research team, however, children may have received optometry/ophthalmology care via regular referral channels (e.g., family physicians, teachers) |
Who may qualify
- Ages
- 3 to 8 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child
Key inclusion criteria (2 listed)
- Screening: children enrolled in senior kindergarten (age 5-6 years)
- Follow-up: children enrolled in Grade 2 (age 7-8 years)
Key exclusion criteria (1 listed)
- None
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 HOTV Acuity TestThis is one of the most sensitive tests of acuity for vision screening of young children. The child is asked to recognize a letter (H,O,T,V) that is surrounded by bars to induce the crowding effects typical of amblyopia. Children were tested monocularly and was required to achieve at least 20/32 in each eye to pass. Children already wearing glasses were tested with their glasses on. | Other | Screened Schools |
| Preschool Randot Stereoacuity TestThis is a reliable screening test for stereo depth perception for young children. Children wear polarized stereoglasses and are asked to identify or match shapes that are "hiding in the snow", which cannot be perceived if the child has abnormal binocular vision. Children were required to achieve at least 60 arcseconds of disparity to pass. Children already wearing glasses were tested with their glasses worn under the stereo glasses. | Other | Screened Schools |
| Plusoptix AutorefractorAutorefractors are electronic devices that measure refractive errors by focusing a light onto the child's eyes and recording how their reflections from the retina return to the camera. The Plusoptix has been shown to have high sensitivity and specificity in previous research. AAPOS (2013) guidelines were used to determine the referral criteria. | Device | Screened Schools |
| Comprehensive Eye ExamChildren who did not pass all three screening tests were referred for full cycloplegic optometry exams, with a parent/guardian present. Optometrists assessed visual history, monocular visual acuity (near \& far), strabismus, binocular function, abnormalities of the anterior segment, and cycloplegic refraction. If the optometrist prescribed glasses, frames were chosen at the time of the exam and the glasses were dispensed either at school (with an optician) or at the optometrist's office. | Other | Screened Schools |
Primary outcome
Prevalence of amblyopia
Time frame: 16 months
Prevalence of suspected amblyopia, defined as 2-or-greater line difference in acuity between eyes
Prevalence of refractive errors
Time frame: 16 months
Untreated clinically significant refractive errors defined by AAPOS (2013) guidelines
Prevalence of reduced stereo vision
Time frame: 16 months
Stereoacuity is often reduced in patients with some types of amblyopia, and will defined as worse than 30 arcsec
2 secondary outcomes
Proportion of below-average readers Year 1
Time frame: 10 months
Proportion of below-average readers Year 2
Time frame: 22 months
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Mar 2020.
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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.
Agnes Wong principal investigator
The Hospital for Sick Children
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Crowded HOTV Acuity Test, Preschool Randot Stereoacuity Test and Plusoptix Autorefractor in people with Amblyopia, run by The Hospital for Sick Children at 1 site in Canada.
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 2 inclusion and 1 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: finished, as of the sponsor's last update on 19 Mar 2020. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. 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 is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Prevalence of amblyopia (time frame: 16 months). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 19 Mar 2020.