Prevalence of undetected ocular conditions in a pilot sample of school children.

Parents of 134 children (age 5-18 years; 84% participation) attending a private school gave informed consent for their child's participation in a pilot study to demonstrate the feasibility and estimate sample size for a larger study of myopia prevalence, the Sydney Myopia Study. LogMAR visual acuity and other ocular assessments, including cycloplegic autorefraction (tropicamide 1%) and examination of the media and fundus, were performed. The prevalence of significant ocular conditions was 28.2%. Eleven children (8.4%) wore glasses. Five were referred for a change in their correction. Previously undetected ocular conditions (19.8%) included one child with ocular pathology and four children with strabismus. Uncorrected refractive error (16.8%) was the most common reason for referral and was more predominant in the senior students (25%), corresponding with an age-related shift in mean spherical equivalent refraction towards myopia (less than 7 years: +0.40 +/- 0.60 D; more than 15 years: -1.15 +/- 1.18 D). Three senior students were classified as having socially significant correctable vision impairment. These findings suggest that reliance on ad hoc referrals could result in delayed referral and that vision screening in both early and later school years may be desirable.