title: [Peripheral refraction: cause or effect of refraction development?]
abstract: OBJECTIVE
  to study peripheral refraction and the shape of the eyeball in children with different clinical refraction.
  
  
  METHODS
  Using an original method, peripheral refraction was measured at 10-12 degrees temporally and nasally from the fovea in 56 right eyes with different clinical, or axial, refraction of 20 boys and 36 girls aged 7 to 16 years (11.9±1.17 years on average). The shape of the eyeball was judged of by the ratio of its anterior-posterior axial length (AL) to horizontal diameter (HD).
  
  
  RESULTS
  The incidence and value of peripheral myopic defocus in children appeared to decrease with clinical refraction increasing from high hyperopia to high myopia. This was the first time, mixed peripheral refraction was found in children, occurring more frequently in higher myopia. This mixed peripheral defocus, shown to be a transitional stage between relative peripheral myopia and relative hyperopia, indicates non-uniform stretching of posterior pole tissues in the course of refraction development and myopia progression. As ocular refraction increases from high hyperopia to high myopia, the growth of AL outpaces that of HD.
  
  
  CONCLUSIONS
  Obviously, natural peripheral defocus results from changes in size and shape of the eyeball in the course of refraction development.
authors.affiliation: Moscow Helmholtz Research Institute of Eye Diseases, Ministry of Health of the Russian Federation, 14/19 Sadovaya-Chernogryazskaya St., Moscow, Russian Federation, 105062.
authors.forename: E P
authors.initials: EP
authors.lastname: Tarutta
authors.affiliation: Moscow Helmholtz Research Institute of Eye Diseases, Ministry of Health of the Russian Federation, 14/19 Sadovaya-Chernogryazskaya St., Moscow, Russian Federation, 105062.
authors.forename: E N
authors.initials: EN
authors.lastname: Iomdina
authors.affiliation: Moscow Helmholtz Research Institute of Eye Diseases, Ministry of Health of the Russian Federation, 14/19 Sadovaya-Chernogryazskaya St., Moscow, Russian Federation, 105062.
authors.forename: N G
authors.initials: NG
authors.lastname: Kvaratskheliya
authors.affiliation: Moscow Helmholtz Research Institute of Eye Diseases, Ministry of Health of the Russian Federation, 14/19 Sadovaya-Chernogryazskaya St., Moscow, Russian Federation, 105062.
authors.forename: S V
authors.initials: SV
authors.lastname: Milash
authors.affiliation: Moscow Helmholtz Research Institute of Eye Diseases, Ministry of Health of the Russian Federation, 14/19 Sadovaya-Chernogryazskaya St., Moscow, Russian Federation, 105062.
authors.forename: G V
authors.initials: GV
authors.lastname: Kruzhkova
mesh_terms: D000293:Adolescent; D058452:Axial Length, Eye / Q000254:growth & development*; D002648:Child; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D009216:Myopia / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D012029:Refraction, Ocular / Q000502:physiology*; D012030:Refractive Errors / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology