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Zagreb Amblyopia Preschool Screening Study: near and distance visual acuity testing increase the diagnostic accuracy
Mladen Bušić, Mirjana Bjeloš1, Mladen Petrovečki
1Mirjana Bjeloš, University Eye Clinic, University Hospital "Sveti Duh", Sveti Duh 64, Zagreb, Croatia, mbjelos@mef.hr.
Insights
The Zagreb Amblyopia Preschool Screening (ZAPS) protocol effectively screened 15,648 children for amblyopia. This new protocol demonstrated high sensitivity and specificity, identifying a higher prevalence of amblyopia in preschool children.
Area of Science:
- Ophthalmology
- Pediatric Optometry
Background:
- Amblyopia, or
- lazy eye
- , is a leading cause of vision impairment in children.
- Early detection and intervention are crucial for effective treatment.
- Existing screening methods may have limitations in accuracy and scope.
Purpose of the Study:
- To introduce and evaluate the Zagreb Amblyopia Preschool Screening (ZAPS) protocol.
- To assess the diagnostic accuracy of the ZAPS protocol for amblyopia in preschool-aged children.
- To determine the prevalence of amblyopia in the target population using the new protocol.
Main Methods:
- The ZAPS study screened 15,648 children aged 48-54 months.
- Near and distance visual acuity (VA) was tested using Lea Symbols in lines.
- Children failing initial VA testing were re-tested and referred for comprehensive eye examination if necessary.
Main Results:
- The ZAPS protocol achieved high testability (99.19%), sensitivity (100.00%), and specificity (96.68%).
- An estimated amblyopia prevalence of 8.08% was identified, which is higher than previously reported.
- The protocol successfully identified all amblyopia cases with a pass level of ≤0.1 logMAR.
Conclusions:
- The ZAPS protocol, utilizing Lea Symbols in lines, provides a highly accurate method for preschool amblyopia screening.
- The study highlights the importance of both near and distance VA testing for comprehensive screening.
- The findings suggest a higher prevalence of amblyopia in preschool children than previously recognized, underscoring the need for effective screening tools.
Aim:
To present and evaluate a new screening protocol for amblyopia in preschool children.
Methods:
Zagreb Amblyopia Preschool Screening (ZAPS) study protocol performed screening for amblyopia by near and distance visual acuity (VA) testing of 15 648 children aged 48-54 months attending kindergartens in the City of Zagreb County between September 2011 and June 2014 using Lea Symbols in lines test. If VA in either eye was >0.1 logMAR, the child was re-tested, if failed at re-test, the child was referred to comprehensive eye examination at the Eye Clinic.
Results:
78.04% of children passed the screening test. Estimated prevalence of amblyopia was 8.08%. Testability, sensitivity, and specificity of the ZAPS study protocol were 99.19%, 100.00%, and 96.68% respectively.
Conclusion:
The ZAPS study used the most discriminative VA test with optotypes in line as they do not underestimate amblyopia. The estimated prevalence of amblyopia was considerably higher than reported elsewhere. To the best of our knowledge, the ZAPS study protocol reached the highest sensitivity and specificity when evaluating diagnostic accuracy of VA tests for screening. The pass level defined at ≤0.1 logMAR for 4-year-old children, using Lea Symbols in lines missed no amblyopia cases, advocating that both near and distance VA testing should be performed when screening for amblyopia.
