Abstract
Abstract: :
Purpose: The prevalence of different types of strabismus and amblyopia in Japan remains largely unknown, and only a limited number of studies involving a few hundreds children have been conducted to date. The purpose of this study is to elucidate the prevalence of strabismus and amblyopia in a large population of elementary school children from grade 1 to grade 6 with the ages ranging from 6 to 12 years in Japan. Methods: Eye examinations, including visual acuity testing and inspection of ocular surface and eye alignment, are conducted usually by ophthalmologists in elementary schools once a year according to the School Health Law in Japan. Children suspected of eye diseases including strabismus and amblyopia are then sent to ophthalmologists for detailed examinations and they bring back the results to schools. Schools report the summary to the education committee in each city or town, and the results of eye diseases are made public on home pages of the Prefectural Government and the Education Ministry of the Central Government. The prevalence of strabismus and amblyopia remains unknown from data on these home pages because these diseases are comprised in the entity of eye diseases. In this study, questionnaires asking the number of children with different types of strabismus and amblyopia were sent to all elementary schools in Okayama Prefecture and the results were summarized. Results: The number of children covered by the return of questionnaires was 86220 (76.1%) of 113,254 total pupils including grade 1 to grade 6 in Okayama Prefecture in the year 2003. The total numbers of children with strabismus and amblyopia including grade 1 to 6 were 1113 (1.29%) and 125 (0.14%), respectively. The numbers of children with any types of exotropia and any types of esotropia were 602 (0.70%) and 247 (0.29%), respectively. The major types of strabismus and amblyopia were intermittent exotropia in 105 children (0.12%), accommodative esotropia in 19 children (0.02%), anisometropic amblyopia in 23 children (0.03%), and ametropic amblyopia in 12 children (0.01%). Conclusions: This is the first study to show the prevalence of strabismus and amblyopia in a large population of Japanese elementary school children.
Keywords: amblyopia • strabismus • strabismus: diagnosis and detection