A systematic review of vision screening tests for the detection of amblyopia.

OBJECTIVE To review the test characteristics and the quality of evidence regarding available screening tests for the detection of amblyopia in preschool-aged children to help primary care practitioners select a screening strategy. DESIGN Systematic review of published studies. DATA SOURCES The MEDLINE database was searched from 1966 through January 1999 using a broad and inclusive strategy. A total of 9551 citations were identified. STUDY SELECTION All studies that compared the results of commercially available screening tests in preschool-aged children to ophthalmologic examination. DATA EXTRACTION The setting of the study, the age of the population, the type of screening test, criteria for a positive screen, criteria for the ophthalmologic examination, test characteristics, and measures of reliability were abstracted by 2 reviewers for each selected study. DATA SYNTHESIS Four eligible articles were identified that studied the test characteristics of 3 screening tests. None of these studies were performed in a primary care setting. Each study used different criteria for failure of the ophthalmologic examination. None of the studies measured observer or test reliability. CONCLUSIONS Few high-quality data exist regarding the performance of preschool vision screening. Important future work should include the development of a consensus gold standard ophthalmologic examination and evaluation of screening tests in the primary care setting.