title: Stereoacuity and Related Factors: The Shandong Children Eye Study.
abstract: OBJECTIVE
  To assess stereoacuity in a population-based sample of children and to examine ocular and systemic parameters related to stereoacuity.
  
  
  METHODS
  Using a random cluster sampling method, four- to 18-year-old children from kindergartens, elementary schools, junior high schools and senior high schools from a rural area and an urban area in the East Chinese province of Shandong were included in the school-based cross-sectional study. All participants underwent a comprehensive eye examination including assessment of cycloplegic refraction and measurement of stereoacuity using the Titmus Stereo test.
  
  
  RESULTS
  Out of 6364 eligible children, 5780 (90.8%) children with a mean age of 10.1 ± 3.2 years (range: 4 to 18 years) participated. Mean (± standard deviation) stereoacuity was 50.2 ± 50.6 arc seconds. Stereoacuity improved significantly (P<0.01) from the age group of 4 years to the age group of 6 to 7 years, then showed a plateau, deteriorated (P = 0.001) for both sexes from the age group of 9 years to the age group of 12 years (P<0.001), after which it improved (P = 0.001) again in the age group of 16 years or older to the pre-puberty values. In multivariate analysis, larger angle of binocular disparity (i.e., lower stereoacuity) was significantly associated with lower best corrected visual acuity (logMAR; P<0.001), higher intereye difference in refractive error (spherical equivalent) (P<0.001), higher cylindrical refractive error (P<0.001), higher refractive error (spherical value; P<0.001), higher intereye difference in best corrected visual acuity (logMAR) (P = 0.001), higher intereye difference in axial length (P = 0.001), and rural region of habitation (P = 0.006).
  
  
  CONCLUSIONS
  Stereoacuity as tested with the Titmus Stereo test improved significantly from an age of 4 years to an age of 6 and 7 years, then remained constant, temporarily deteriorated for both sexes in pre-puberty and puberty, after which it improved again to pre-puberty or better values at the age of 16 years or older. Lower stereoacuity was associated with lower best corrected visual acuity and higher intereye difference in best corrected visual acuity, higher cylindrical and spherical refractive errors, higher inter-eye difference in refractive error, higher intereye difference in axial length, and rural region of habitation.
authors.affiliation: Eye Institute of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China.
authors.forename: Da-Dong
authors.initials: DD
authors.lastname: Guo
authors.affiliation: Ophthalmology & Optometry School, Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China.
authors.forename: Jian-Feng
authors.initials: JF
authors.lastname: Wu
authors.affiliation: The Second Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China.
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Hu
authors.affiliation: The Second Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
authors.affiliation: The Second Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China.
authors.forename: Tai-Liang
authors.initials: TL
authors.lastname: Lv
authors.affiliation: Eye Institute of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China.
authors.forename: Wen-Jun
authors.initials: WJ
authors.lastname: Jiang
authors.affiliation: Eye Institute of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Wu
authors.affiliation: The Second Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China.
authors.forename: Xing-Rong
authors.initials: XR
authors.lastname: Wang
authors.affiliation: Department of Ophthalmology, Medical Faculty Mannheim of the Ruprecht-Karls-University Heidelberg, Germany.
authors.forename: Jost B
authors.identifier: http://orcid.org/0000-0003-2972-5227
authors.initials: JB
authors.lastname: Jonas
authors.affiliation: Eye Institute of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China.
authors.forename: Hong-Sheng
authors.initials: HS
authors.lastname: Bi
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002681:China; D003430:Cross-Sectional Studies; D005123:Eye; D005260:Female; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D012029:Refraction, Ocular; D012030:Refractive Errors / Q000175:diagnosis*; D015203:Reproducibility of Results; D012424:Rural Population; D012574:Schools; D011795:Surveys and Questionnaires; D014505:Urban Population; D014792:Visual Acuity