Sensitivity and specificity of school nurse screening for hypermetropia and convergence insufficiency exophoria in primary schoolchildren in Denmark

BACKGROUND: To determine the sensitivity and specificity of school nurse screening for hypermetropia and convergence insufficiency exophoria (CIE) in schoolchildren.

METHODS: Near point of convergence and distance visual acuity with +2.00D lenses were measured in 2097 children (6-15 years) during standard school nurse screening in the municipality of Randers, Denmark. One hundred and ninety-four children with positive screening results (near point of convergence >10 cm and/or distance visual acuity improved or maintained with +2.00D) and 182 controls with negative screening results received a full vision assessment, including cycloplegic refraction and orthoptic evaluation.

RESULTS: Sensitivity and specificity of screening was 0.75 and 0.69 for CIE and 0.59 and 0.87 for hypermetropia (≥+2.00), respectively. While precision of screening for CIE was significantly higher for symptomatic children aged 9-15 than for younger and asymptomatic children, precision of screening for hypermetropia was independent of age and presence of visually related symptoms.

CONCLUSION: While precision of screening for CIE and hypermetropia (>+2.00) was low, additional vision evaluation of children older than 9 years with asthenopic symptoms identified most children with CIE with a low absolute number of false positives.