title: The temporal and nasal retinal arteriolar and venular angles in preterm infants.
abstract: OBJECTIVE
  To determine the angle between the temporal or nasal retinal vessels in preterm infants and to determine the relationship of these angles to birthweight (BW), gestational age (GA) and retinopathy of prematurity (ROP) status.
  
  
  METHODS
  Colour digital images were acquired during ROP screening examinations in infants born with a range of BWs and GAs between 33 and 42 weeks postmenstrual age. Four retinal vessel angles were measured: temporal venular angle, temporal arteriolar angle (tAA), nasal venular angle and nasal arteriolar angle. Measurements were performed by Computer-Aided Image Analysis of the Retina, a validated semi-automated computer software program. The relationship of each of four angles to BW and also to GA was determined using Mann-Whitney test and Spearman's rho, respectively.
  
  
  RESULTS
  tAA was significantly narrower in infants with ROP and correlated positively with BW and GA. The other vessel angles, temporal venular angle, nasal arteriolar angle and nasal venular angle, showed no significant correlation with BW, GA or ROP status.
  
  
  CONCLUSIONS
  The retinal vessel angles can be quantified in a simple repeatable manner. tAA correlated positively with BW and GA, and was significantly narrower in infants with stage 3 ROP than in those without ROP or with mild disease.
authors.affiliation: Department of Optometry and Visual Science, City University, London, UK.
authors.forename: Karen
authors.initials: K
authors.lastname: Wong
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Ng
authors.forename: Anna
authors.initials: A
authors.lastname: Ells
authors.forename: Alistair R
authors.initials: AR
authors.lastname: Fielder
authors.forename: Clare M
authors.initials: CM
authors.lastname: Wilson
mesh_terms: D001160:Arterioles / Q000473:pathology; D002170:Canada / Q000453:epidemiology; D005865:Gestational Age; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007234:Infant, Premature; D009898:Optic Disk / Q000098:blood supply*; D012171:Retinal Vessels / Q000473:pathology*; D012178:Retinopathy of Prematurity / Q000453:epidemiology / Q000473:pathology*; D013699:Temporal Arteries / Q000473:pathology*; D006113:United Kingdom / Q000453:epidemiology; D014699:Venules / Q000473:pathology