title: Development of smooth pursuit eye movements in very prematurely born infants: 2. The low-risk subgroup.
abstract: OBJECTIVE
  To investigate the impact of premature birth on visual tracking in a group of 37 infants, born before the 32nd gestational weeks (mean 29 + 6 weeks) and diagnosed as being without major neonatal complications. This paper is a part of the LOVIS study (Strand Brodd, Ewald, Grönqvist, Holmström, Strömberg, Von Hofsten, et al. Acta Pediatrica, 2011).
  
  
  METHODS
  At 2 and 4 months corrected age, eye and head movements were measured when the infant tracked a moving object. The eye movements were analysed in terms of smooth pursuit and saccades (Vision Res, 37, 1997, 1799; Exp Brain Res, 146, 2002, 257). Accuracy of gaze, proportion of smooth pursuit, head movements and saccades were calculated.
  
  
  RESULTS
  Between 2 and 4 months of age, all infants improved their ability to smoothly pursue a moving object. However, at both occasions, the preterm infants had less proportion smooth pursuit than the full-term infants. The groups did not differ with respect to gaze and head movements, but the saccade frequency was higher for the very preterms in some of the conditions.
  
  
  CONCLUSIONS
  The development of smooth pursuit in the low-risk preterm infant group was strongly delayed compared to typically developed infants. Thus, the 2 months or more extra visual experience did not have a distinguishable positive effect on visuo-motor development as expressed in smooth pursuit.
authors.affiliation: Department of Psychology, Uppsala University, Uppsala, Sweden.
authors.forename: Helena
authors.initials: H
authors.lastname: Grönqvist
authors.forename: Katarina Strand
authors.initials: KS
authors.lastname: Brodd
authors.forename: Kerstin
authors.initials: K
authors.lastname: Rosander
mesh_terms: D002657:Child Development / Q000502:physiology; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology; D005500:Follow-Up Studies; D005865:Gestational Age; D019416:Head Movements / Q000502:physiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D008297:Male; D011698:Pursuit, Smooth / Q000502:physiology*; D018570:Risk Assessment; D012438:Saccades / Q000502:physiology; D047929:Term Birth / Q000502:physiology