title: Relationship between the retinal microvasculature and renal volume in low-birth-weight babies.
abstract: OBJECTIVE
  We performed a study to assess whether the development of the retinal microvasculature reflects nephron growth and therefore nephron number.
  
  
  METHODS
  In our study, we determined the association between kidney volume (nephron number) and the retinal microvasculature of term low-birth-weight (LBW) and normal-birth-weight (NBW) infants (11 LBW and 27 NBW).
  
  
  RESULTS
  LBW infants had significantly larger retinal arteriolar and venular diameters (104.2 ± 21.4 versus 87.0 ± 12.7 μm; p = 0.004; 146.8 ± 19.5 versus 128.0 ± 19.5 μm; p = 0.01, respectively) compared with NBW infants. LBW infants also had smaller mean renal volumes (9.3 ± 2.3 versus 12.2 ± 3.1 ml; p = 0.008). There were negative correlations between retinal arteriolar and venular diameters and renal volumes (r = -0.34, p < 0.05; r = -0.37, p < 0.05, respectively).
  
  
  CONCLUSIONS
  The larger the kidney (and, by implication, the greater the nephron number), the smaller are the diameters of retinal arterioles and venules. Thus, the degree of dilation of the retinal microvasculature provides an indirect index of renal growth.
authors.affiliation: Department of Neonatology, The Townsville Hospital, Queensland, Australia. Yoga_Kandasamy@health.qld.gov.au
authors.forename: Yogavijayan
authors.initials: Y
authors.lastname: Kandasamy
authors.forename: Roger
authors.initials: R
authors.lastname: Smith
authors.forename: Ian M R
authors.initials: IM
authors.lastname: Wright
mesh_terms: D001160:Arterioles / Q000033:anatomy & histology*; D003430:Cross-Sectional Studies; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007668:Kidney / Q000000981:diagnostic imaging; D055806:Microvessels / Q000033:anatomy & histology*; D009399:Nephrons / Q000254:growth & development*; D009929:Organ Size; D012160:Retina / Q000033:anatomy & histology*; D014463:Ultrasonography; D014699:Venules / Q000033:anatomy & histology