title: Distribution and determinants of eye size and shape in newborn children: a magnetic resonance imaging analysis.
abstract: OBJECTIVE
  To determine the eye size and shape obtained by magnetic resonance imaging (MRI), and to determine associations with antenatal factors in newborn children.
  
  
  METHODS
  A subset of 173 full-term newborn children from the Growing Up in Singapore Towards Healthy Outcomes (GUSTO) birth cohort underwent MRI. Eye volume and surface area were measured. Eye shape was assessed qualitatively from three-dimensional models, and quantitatively by measurement of longitudinal axial length (AL, the length from the posterior corneal surface to the retinal surface), and horizontal width and vertical height of the internal eye along the cardinal axes. Oblateness was calculated as 1-(AL/width) or 1-(AL/height). Oblate eyes had oblateness>+0.01, spherical eyes had oblateness between +0.01 and -0.01, and prolate eyes had oblateness<-0.01.
  
  
  RESULTS
  A total of 346 eyes of 173 children were included. Mean oblateness using width was -0.06±0.05 (range, -0.23 to +0.08), and mean oblateness using height was -0.01±0.04 (range, -0.19 to +0.13). Using width, most eyes were prolate (294 eyes, 85%); and using height, the largest proportion of eyes was prolate (163 eyes, 47%). Eyes with longer ALs had greater widths, heights, volumes, and surface areas than eyes with shorter ALs (P<0.001 for all). With increasing AL, eyes became increasingly prolate. Children of less educated mothers had longer ALs (P=0.02). Malay children had larger eye volumes and surface areas than Chinese or Indian children.
  
  
  CONCLUSIONS
  Most newborn Singaporean Asian children are born with prolate eyes. A longitudinal study is required to determine if globe shape at birth influences subsequent refractive changes.
authors.affiliation: Singapore Eye Research Institute, Singapore.
authors.forename: Laurence Shen
authors.initials: LS
authors.lastname: Lim
authors.forename: Gim Hong
authors.initials: GH
authors.lastname: Chong
authors.forename: Pei Ting
authors.initials: PT
authors.lastname: Tan
authors.forename: Yap-Seng
authors.initials: YS
authors.lastname: Chong
authors.forename: Kenneth
authors.initials: K
authors.lastname: Kwek
authors.forename: Peter D
authors.initials: PD
authors.lastname: Gluckman
authors.forename: Marielle V
authors.initials: MV
authors.lastname: Fortier
authors.forename: Seang-Mei
authors.initials: SM
authors.lastname: Saw
authors.forename: Anqi
authors.initials: A
authors.lastname: Qiu
mesh_terms: D044466:Asian People; D058452:Axial Length, Eye / Q000033:anatomy & histology; D015331:Cohort Studies; D005123:Eye / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D008297:Male; D015999:Multivariate Analysis; D009216:Myopia / Q000208:ethnology / Q000209:etiology; D009929:Organ Size; D012307:Risk Factors; D012846:Singapore
keywords: image analysis; magnetic resonance imaging; myopia; neonates