Refractive errors, amblyopia risk factors and vision screening in children aged 7-10 years in Aotearoa New Zealand

Abstract

Clinical relevance: Vision screening is important for detecting undiagnosed vision conditions that are common in school-aged children. However, current vision screening protocols are poor at detecting vision conditions that are most common in the Aotearoa New Zealand paediatric population.

Background: Uncorrected refractive error and amblyopia are the most common causes of visual impairment in children. The most appropriate vision screening method depends on the refractive error profile of the population. This study aimed to: estimate the prevalence of refractive errors and amblyopia risk factors among children living in Aotearoa New Zealand; describe previous participation in preschool vision screening and determine the diagnostic accuracy of potential screening methods.

Methods: Children aged 7-10 years received comprehensive eye examinations, including cycloplegic refraction, in their school. Eye examination results were assessed for refractive error and amblyopia risk factors. The sensitivity and specificity of individual vision tests for detecting any vision conditions was calculated to assess the most effective tests for vision screening.

Results: Eye examinations were completed for 237 children and cycloplegic refraction data was available for 220 of these children. Significant refractive error (need for glasses) was detected in 23.6% of children (7.7% myopia, 7.7% hyperopia, 15.0% astigmatism). Amblyopia risk factors were detected in 9.1% of children. Preschool vision screening had been completed by 78.5% of children. Distance visual acuity screening alone had a sensitivity of 39% for detecting vision conditions, with addition of the Spot Vision Screener improving sensitivity to 65%.

Conclusion: Astigmatism is the most frequent refractive error among children aged 7-10 years living in Aotearoa New Zealand. Distance visual acuity screening alone is ineffective in detecting refractive error in children in Aotearoa New Zealand. Further research investigating refractive errors across the paediatric population in Aotearoa New Zealand is required to determine the optimal timing and appropriate protocols for school-aged vision screening.

Keywords: Child; New Zealand; refractive error; school-aged; vision screening.