MedPath

Efficacy of Visual Screening in Ontario

Not Applicable
Completed
Conditions
Amblyopia
Registration Number
NCT02458846
Lead Sponsor
The Hospital for Sick Children
Brief 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. 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.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
2597
Inclusion Criteria
  • Screening: children enrolled in senior kindergarten (age 5-6 years)
  • Follow-up: children enrolled in Grade 2 (age 7-8 years)
Exclusion Criteria

• None

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Primary Outcome Measures
NameTimeMethod
Prevalence of reduced stereo vision16 months

Stereoacuity is often reduced in patients with some types of amblyopia, and will defined as worse than 30 arcsec

Prevalence of refractive errors16 months

Untreated clinically significant refractive errors defined by AAPOS (2013) guidelines

Prevalence of amblyopia16 months

Prevalence of suspected amblyopia, defined as 2-or-greater line difference in acuity between eyes

Secondary Outcome Measures
NameTimeMethod
Proportion of below-average readers Year 222 months

Proportion of Grade 2 children reading 1 SD below average

Proportion of below-average readers Year 110 months

Proportion of Grade 1 children reading 1 SD below average

Trial Locations

Locations (1)

The Hospital for Sick Children

🇨🇦

Toronto, Ontario, Canada

The Hospital for Sick Children
🇨🇦Toronto, Ontario, Canada

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