title: Longitudinal changes in choroidal thickness and eye growth in childhood.
abstract: OBJECTIVE
  To examine longitudinal changes in choroidal thickness and axial length in a population of children with a range of refractive errors.
  
  
  METHODS
  One hundred and one children (41 myopes and 60 nonmyopes) aged 10 to 15 years participated in this prospective, observational longitudinal study. For each child, 6-month measures of choroidal thickness (using enhanced depth imaging optical coherence tomography) and axial ocular biometry were collected four times over an 18-month period. Linear mixed-models were used to examine the longitudinal changes in choroidal thickness and the relationship between changes in choroidal thickness and axial eye growth over the study period.
  
  
  RESULTS
  A significant group mean increase in subfoveal choroidal thickness was observed over 18 months (mean increase 13 ± 22 μm, P < 0.001). Myopic children exhibited significantly thinner choroids compared with nonmyopic children (P < 0.001), although there was no significant time by refractive group interaction (P = 0.46), indicating similar changes in choroidal thickness over time in myopes and nonmyopes. However, a significant association between the change in choroidal thickness and the change in axial length over time was found (P < 0.001, β = -0.14). Children showing faster axial eye growth exhibited significantly less choroidal thickening over time compared with children showing slower axial eye growth.
  
  
  CONCLUSIONS
  A significant increase in choroidal thickness occurs over an 18-month period in normal 10- to 15-year-old children. Children undergoing faster axial eye growth exhibited less thickening and, in some cases, a thinning of the choroid. These findings support a potential role for the choroid in the mechanisms regulating eye growth in childhood.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Read
authors.forename: David
authors.initials: D
authors.lastname: Alonso-Caneiro
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Vincent
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Collins
mesh_terms: D000293:Adolescent; D058452:Axial Length, Eye / Q000473:pathology*; D001699:Biometry / Q000379:methods; D002648:Child; D002829:Choroid / Q000473:pathology*; D005123:Eye / Q000254:growth & development*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009216:Myopia / Q000503:physiopathology*; D011446:Prospective Studies; D041623:Tomography, Optical Coherence / Q000379:methods