Clinical trial NCT02458846: Efficacy of Visual Screening in Ontario
Official title: The Efficacy of a Visual Screening Program to Reduce Later Amblyopia and Untreated Refractive Errors
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Amblyopia
Lead sponsor: The Hospital for Sick Children
Sponsor class: OTHER
First posted: 2015-06-01
Enrollment: 2597
Sex: ALL
Minimum age (years): 3
Maximum age (years): 8
Standard ages: CHILD
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: SINGLE_GROUP
Primary purpose: DIAGNOSTIC

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.

Eligibility criteria: 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

Primary outcomes:
measure: Prevalence of amblyopia
timeFrame: 16 months
measure: Prevalence of refractive errors
timeFrame: 16 months
measure: Prevalence of reduced stereo vision
timeFrame: 16 months
Secondary outcomes:
measure: Proportion of below-average readers Year 1
timeFrame: 10 months
measure: Proportion of below-average readers Year 2
timeFrame: 22 months
Other outcomes:
Locations:
city: Toronto
country: Canada
facility: The Hospital for Sick Children
state: Ontario
Study officials:
affiliation: The Hospital for Sick Children
name: Agnes Wong
role: PRINCIPAL_INVESTIGATOR
References: