Feasibility of a school-based vision screening program to detect undiagnosed visual problems in kindergarten children in Ontario

BACKGROUND:Visual problems can negatively affect visual development and learning but often go undetected. We assessed the feasibility of scaling up a school-based screening program to identify and treat kindergarten children with visual problems.METHODS:We conducted a prospective cohort study offering vision screening to junior (JK) and senior kindergarten (SK) children attending 43 schools in 15 Ontario communities. Screening comprised photoscreeners and tests of visual acuity, stereoacuity and eye alignment. Children who failed any test were referred for a comprehensive eye examination, with treatment as needed (e.g., glasses).RESULTS:Using a passive consent model, 89% of children were screened compared with 62% using an active consent model (p < 0.001). Referral rates to an optometrist varied across schools (mean referral rate for children in JK 53%, range 25%–83%; mean referral rate for children in SK 34%, range 12%–61%). Among 4811 children who were screened, a visual problem was detected in 516 (10.7%), including 164 (3.4%) with amblyopia and 324 (6.7%) with clinically significant refractive errors. For 347 (67.2%) of the children with a visual problem, this was their first eye examination. Rescreening in Year 2 did not lead to detection of additional problems among children who passed screening in Year 1. Regardless of location (child’s school or optometrist’s office), 1563 (68.9%) of children attended the follow-up optometry examination. Most of the children who were surveyed (291 of 322, 90.4%) indicated that they enjoyed vision screening.INTERPRETATION:Many children in Ontario with a visual problem were not being identified by the status quo in 2015–2017. We found that in-school vision screening with follow-up eye examinations is an effective strategy for identifying at-risk children and placing them in eye care before grade 1.

Two previous Canadian studies suggested that about 1 in 5 children aged 3–6 years have a visual problem such as amblyopia or clinically significant refractive errors (i.e., hyperopia, myopia, astigmatism or anisometropia).^1,2 Population-based studies in the United States and other countries have reported similar prevalence.^3–15 The United States Preventive Services Task Force recommends at least 1 vision screening in children between the ages of 3 and 5 years.¹⁶ The Canadian Paediatric Society recommends screening for visual problems at well-child visits for children aged 3–5 years;¹⁷ however, this often does not occur.¹⁸ One report from Ontario showed that only 14% of children under 6 years of age had a comprehensive eye examination in 2013, even though examinations are paid for by provincial health insurance.¹⁹ The underutilization of vision care means that children with amblyopia are not receiving treatment when it is most effective (i.e., before 8 yr of age).^20–22 In addition, early visual problems can negatively affect learning — children with amblyopia read more slowly than those with normal vision,^23,24 and refractive errors are associated with poor reading by grade 1.^25–31We are unaware of any studies to date that have examined the scaling and implementation issues associated with a school-based, vision-screening program in kindergarten, or whether such a program could successfully identify and offer treatment (e.g., glasses) to children with previously undiagnosed visual problems.^32–34 In a study¹ in 1 school (n = 709 children), we investigated what combination of screening tools provided the highest sensitivity and specificity. In the current study, we used this information to test the feasibility of scaling up vision screening to multiple schools in diverse Ontario communities. We investigated whether screening should be offered in both junior kindergarten (JK) and senior kindergarten (SK), whether using an active or passive consent model makes a difference, whether offering follow-up eye examinations at the child’s school can reduce barriers to access, and whether children are receptive to a screening program. These are practical details needed by funders to make decisions about implementing school-based vision screening.     

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