title: Relationship of axial length and retinal vascular caliber in children.
abstract: OBJECTIVE
  Previous studies in older adults suggest that longer axial length is associated with narrower arteriolar caliber. In this study, we re-examined this relationship in a cohort of children, while controlling for the effects of ocular magnification.
  
  
  METHODS
  Cross-sectional study of 767 children aged 7 to 9 years.
  
  
  METHODS
  Retinal vascular calibers were measured from retinal photographs using a computer-based program. Ocular magnification was corrected using the Bengtsson formula. Standardized examination of refraction and ultrasound ocular biometry was performed for all children.
  
  
  RESULTS
  In models that adjusted for age, gender, ethnicity, body mass index, blood pressure, and birth weight, longer axial length was associated strongly with narrower retinal arteriolar caliber (3.18-microm decrease per standard deviation increase in axial length; P < .001) and venular caliber (4.62-microm decrease standard deviation increase in axial length; P < .001) before correction for ocular magnification. However, after correction, these associations no longer were significant (0.44 microm; P = .31, change for arteriolar caliber; and 0.70 microm; P = .25, for venular caliber).
  
  
  CONCLUSIONS
  Our study in children found no association between axial length and retinal vascular caliber after correcting for ocular magnification, suggesting that the previously reported association was likely related to differences in ocular magnification.
authors.affiliation: Centre for Eye Research Australia, University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: Ning
authors.initials: N
authors.lastname: Cheung
authors.forename: Gabriella
authors.initials: G
authors.lastname: Tikellis
authors.forename: Seang Mei
authors.initials: SM
authors.lastname: Saw
authors.forename: F M
authors.initials: FM
authors.lastname: Amirul Islam
authors.forename: Paul
authors.initials: P
authors.lastname: Mitchell
authors.forename: Jie Jin
authors.initials: JJ
authors.lastname: Wang
authors.forename: Tien Yin
authors.initials: TY
authors.lastname: Wong
mesh_terms: D000367:Age Factors; D000886:Anthropometry; D001699:Biometry; D001724:Birth Weight; D001794:Blood Pressure; D015992:Body Mass Index; D002648:Child; D003430:Cross-Sectional Studies; D005006:Ethnicity; D005123:Eye / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D010781:Photography; D012161:Retinal Artery / Q000033:anatomy & histology*; D012737:Sex Factors; D014463:Ultrasonography