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Prevalence of amblyopia among defaulters of preschool vision screening
1Department of Ophthalmology, Addenbrooke's Hospital, Cambridge, United Kingdom.
Insights
Preschool vision screening is less effective with low attendance. The study found similar amblyopia prevalence in children who attended and those who missed screening, highlighting the need to improve screening participation.
Area of Science:
- Ophthalmology
- Public Health
- Pediatrics
Background:
- Amblyopia, or 'lazy eye,' is a leading cause of vision impairment in children.
- Preschool vision screening aims to detect amblyopia early, but its effectiveness depends on participation rates.
Purpose of the Study:
- To evaluate the efficacy of an orthoptist-based preschool vision screening program.
- To determine the prevalence of amblyopia among children who defaulted from preschool vision screening compared to those who attended.
Main Methods:
- A retrospective cohort study analyzed community child health records.
- Preschool vision screening status was determined for 86% of the cohort.
- Amblyopia prevalence was assessed using school entry vision tests, with retesting as needed.
Main Results:
- The attendance rate for preschool vision screening was 79.2%.
- Amblyopia prevalence was 1.3% in screening defaulters and 2.5% in screening attenders.
- No significant difference in amblyopia prevalence was found between the two groups (P=0.53).
Conclusions:
- The effectiveness of preschool vision screening for amblyopia detection is directly linked to its attendance rate.
- Low attendance rates mean a significant number of children with amblyopia may not be identified.
- Improving participation in preschool vision screening programs is crucial for maximizing amblyopia detection.
Abstract:
The prevalence of amblyopia among screening defaulters is an important determinant of the efficacy of amblyopia detection by preschool vision screening. A retrospective cohort study was therefore performed to assess an orthoptist-based preschool vision screening programme. The preschool vision screening status of children in the cohort was determined by reviewing their Community Child Health records. The prevalence of amblyopia among screening defaulters was determined by reviewing each child's school entry vision test (performed at 5.5 years of age), with retesting if a Snellen line acuity of 6/6 in each eye had not been documented. For comparison, the prevalence of amblyopia among screening attenders was also determined. The preschool vision screening status was known for 86.0% (772/898) of the cohort. The attendance rate at preschool vision screening was 79.2%. The prevalence of amblyopia among screening defaulters was 1.3% (95% CI 0.2% to 4.5%). The prevalence of amblyopia among screening attenders was 2.5% (95% CI 1.4% to 4.1%). There was no significant difference in the prevalence of amblyopia between screening defaulters and screening attenders (P=0.53). The efficacy of amblyopia detection by preschool vision screening is therefore highly dependent on its attendance rate. Preschool vision screening programmes with a low attendance rate will fail to detect a significant proportion of children with amblyopia.
