Diagnostic accuracy of vision screening tests for the detection of amblyopia and its risk factors: a systematic review

Aim

This systematic review evaluates the diagnostic accuracy of preschool vision screening tests for the detection of amblyopia and its risk factors.

Methods

The literature searches were conducted in nine bibliographic databases. No limitation to a specific study design, year of publication or language was applied. Studies were included if they compared a vision screening test with a reference test (gold standard) in children from the general population. In addition, the studies had to provide sufficient data to calculate diagnostic accuracy (sensitivity and specificity). Full-text articles were assessed for studies that satisfied the inclusion criteria using the “Quality of Diagnostic Accuracy Studies (QUADAS)” checklist.

Results

Two studies with a longitudinal design and 25 cross-sectional studies met the inclusion criteria. One of the longitudinal studies compared a screening programme in children between 1 and 2 years of age with a re-examination at the age of 8. The sensitivity for the screening programme was 86% (range: 64–97%) and the specificity 99% (range: 98–99%). The second longitudinal study compared screening examinations at 8, 12, 18, 25 and 31 months, with a re-examination at the age of 37 months. In this study, the sensitivity of the screening examination increased with age, while the specificity remained unchanged. The cross-sectional studies evaluated different screening settings, visual acuity tests, auto- or photorefractors and stereo tests. A large variety of reference tests, differing criteria for defining amblyopia and its risk factors and methodological limitations of the studies prevented a valid data interpretation.

Conclusion

Diagnostic test accuracy of preschool vision screening tests can only be sufficiently investigated after establishing age-related values defining amblyopia, refractive errors and binocular disorders. To address these questions, we recommend a controlled longitudinal study design.