Effectiveness of a photoscreener in identifying undiagnosed unilateral amblyopia at vision screening of 3-year-old children in Japan

Purpose In Japan a basic preparatory ophthalmic examination is routinely performed for 3-year-old children. This study aimed to determine the value of incorporating a photoscreener into the examination and evaluate parents’ satisfaction with the photoscreener examination. Study design Prospective study. Methods Children aged 42–47 months in Nagasaki City, Japan, underwent a visual acuity test by a parent at home and by automated vision screening using a photoscreener at their local municipal health center between October 2018 and March 2019. Subjects were children referred to Nagasaki University Hospital for examination after failing either test. Children previously diagnosed with strabismus and/or amblyopia were excluded. A questionnaire survey evaluated the level of satisfaction with the photoscreener-based screening by parents who attended these examinations at the local municipal health center. Results Of children who completed the two tests, 52 (failed visual acuity test, 3; failed photoscreener examination, 49) were referred for examination. Of the 49 photoscreener failures, 12 were diagnosed with amblyopia: unilateral amblyopia with anisometropic hyperopia in 10 (83.3%), and bilateral amblyopia with astigmatism and hyperopia in 2 (16.7%). The photoscreener detected all 12 cases of amblyopia, whereas the home-based visual acuity test detected only two cases. More than 80% of 1035 parents were satisfied with the photoscreener examination. Conclusion Unilateral amblyopia with anisometropic hyperopia was easily overlooked with the home-based test but was detectable by photoscreener examination. The photoscreener proved to be an effective screening tool for amblyopia in children and was considered a satisfactory examination by a high proportion of parents.