title: Normal eye growth in emmetropic schoolchildren.
abstract: OBJECTIVE
  The purpose of this report is to describe the normal growth pattern of the optical components of the eye in a cohort of emmetropic, school-aged children.
  
  
  METHODS
  Emmetropia was defined as refractive error (measured by cycloplegic autorefraction) in the vertical and horizontal meridians of the right eye between +1.00 D and -0.25 D at all the visits. This definition resulted in a sample of 194 children enrolled in the Orinda Longitudinal Study of Myopia (OLSM) between ages 6 and 14 years with at least 2 years of follow-up evaluation (across three annual visits) between 1989 and 2000. The optical components measured included corneal power, anterior chamber depth, crystalline lens thickness, Gullstrand lens power, calculated lens power, crystalline lens index, vitreous chamber depth, and axial length.
  
  
  RESULTS
  Corneal power and anterior chamber depth were best modeled as quadratic functions of ln (age). The model involving the square of the inverse of age best described calculated lens power and crystalline lens index. The relationship between age and crystalline lens thickness was best described using a linear function of age with a point of inflection. A linear function of ln (age) with a point of inflection best described the relationship between age and axial length, Gullstrand lens power, and vitreous chamber depth. For five of the eight components (crystalline lens thickness, Gullstrand lens power, calculated lens power, corneal power, and crystalline lens index), the line modeling the data was negative in overall direction, indicating that the component value decreased with age. The upward trend of the line modeling axial length, anterior chamber depth, and vitreous chamber depth reflected the continued growth of the eye from age 6 years to age 15 years.
  
  
  CONCLUSIONS
  A picture of normal eye growth in emmetropes from ages 6 to 15 years is provided based on a combination of cross-sectional and longitudinal data. Axial elongation, crystalline lens flattening and thinning, and decrease in lens power are its hallmarks.
authors.affiliation: The Ohio State University College of Optometry, Columbus, Ohio 43210-1240, USA. zadnik.4@osu.edu
authors.forename: Karla
authors.initials: K
authors.lastname: Zadnik
authors.forename: Donald O
authors.initials: DO
authors.lastname: Mutti
authors.forename: G Lynn
authors.initials: GL
authors.lastname: Mitchell
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Jones
authors.forename: Deborah
authors.initials: D
authors.lastname: Burr
authors.forename: Melvin L
authors.initials: ML
authors.lastname: Moeschberger
mesh_terms: D000293:Adolescent; D000867:Anterior Chamber / Q000254:growth & development; D002648:Child; D002657:Child Development; D015331:Cohort Studies; D003315:Cornea / Q000254:growth & development / Q000502:physiology; D003430:Cross-Sectional Studies; D005123:Eye / Q000254:growth & development*; D006801:Humans; D008137:Longitudinal Studies; D008954:Models, Biological