title: Eye size and shape in newborn children and their relation to axial length and refraction at 3 years.
abstract: OBJECTIVE
  To determine if eye size and shape at birth are associated with eye size and refractive error 3 years later.
  
  
  METHODS
  A subset of 173 full-term newborn infants from the Growing Up in Singapore Towards healthy Outcomes (GUSTO) birth cohort underwent magnetic resonance imaging (MRI) to measure the dimensions of the internal eye. Eye shape was assessed by an oblateness index, calculated as 1 - (axial length/width) or 1 - (axial length/height). Cycloplegic autorefraction (Canon Autorefractor RK-F1) and optical biometry (IOLMaster) were performed 3 years later.
  
  
  RESULTS
  Both eyes of 173 children were analysed. Eyes with longer axial length at birth had smaller increases in axial length at 3 years (p < 0.001). Eyes with larger baseline volumes and surface areas had smaller increases in axial length at 3 years (p < 0.001 for both). Eyes which were more oblate at birth had greater increases in axial length at 3 years (p < 0.001). Using width to calculate oblateness, prolate eyes had smaller increases in axial length at 3 years compared to oblate eyes (p < 0.001), and, using height, prolate and spherical eyes had smaller increases in axial length at 3 years compared to oblate eyes (p < 0.001 for both). There were no associations between eye size and shape at birth and refraction, corneal curvature or myopia at 3 years.
  
  
  CONCLUSIONS
  Eyes that are larger and have prolate or spherical shapes at birth exhibit smaller increases in axial length over the first 3 years of life. Eye size and shape at birth influence subsequent eye growth but not refractive error development.
authors.affiliation: Singapore Eye Research Institute, Singapore City, Singapore.
authors.forename: Laurence Shen
authors.initials: LS
authors.lastname: Lim
authors.affiliation: Saw Swee Hock School of Public Health, National University of Singapore, Singapore City, Singapore.
authors.forename: Sharon
authors.initials: S
authors.lastname: Chua
authors.affiliation: Biostatistics Unit, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore City, Singapore.
authors.forename: Pei Ting
authors.initials: PT
authors.lastname: Tan
authors.affiliation: Department of Obstetrics & Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore City, Singapore.
authors.forename: Shirong
authors.initials: S
authors.lastname: Cai
authors.affiliation: Department of Obstetrics & Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore City, Singapore.|Singapore Institute for Clinical Sciences, The Agency for Science, Technology and Research, Singapore City, Singapore.
authors.forename: Yap-Seng
authors.initials: YS
authors.lastname: Chong
authors.affiliation: Department of Maternal Fetal Medicine, KK Women's and Children's Hospital, Singapore City, Singapore.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Kwek
authors.affiliation: Singapore Institute for Clinical Sciences, The Agency for Science, Technology and Research, Singapore City, Singapore.|Liggins Institute, University of Auckland, Auckland, New Zealand.
authors.forename: Peter D
authors.initials: PD
authors.lastname: Gluckman
authors.affiliation: KK Women's and Children's Hospital, Singapore City, Singapore.
authors.forename: Marielle V
authors.initials: MV
authors.lastname: Fortier
authors.affiliation: Department of Ophthalmology, National University Hospital, Singapore City, Singapore.
authors.forename: Cheryl
authors.initials: C
authors.lastname: Ngo
authors.affiliation: Department of Biomedical Engineering, National University of Singapore, Singapore City, Singapore.|Clinical Imaging Research Center, National University of Singapore, Singapore City, Singapore.
authors.forename: Anqi
authors.initials: A
authors.lastname: Qiu
authors.affiliation: Singapore Eye Research Institute, Singapore City, Singapore.|Saw Swee Hock School of Public Health, National University of Singapore, Singapore City, Singapore.
authors.forename: Seang-Mei
authors.initials: SM
authors.lastname: Saw
mesh_terms: D058452:Axial Length, Eye / Q000033:anatomy & histology / Q000502:physiology; D001699:Biometry / Q000379:methods; D002675:Child, Preschool; D015331:Cohort Studies; D005123:Eye / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D009929:Organ Size; D012029:Refraction, Ocular / Q000502:physiology*; D012030:Refractive Errors / Q000473:pathology*; D014787:Vision Tests
keywords: imaging; magnetic resonance imaging; myopia; ocular development