ABSTRACT
BACKGROUND: Typically developing infants track moving objects with eye and head movements in a smooth and predictive way at 4 mo of age, but this ability is delayed in very preterm infants. We hypothesized that visual tracking ability in very preterm infants predicts later neurodevelopment. METHOD: In 67 very preterm infants (gestational age<32 wk), eye and head movements were assessed at 4 mo corrected age while the infant tracked a moving object. Gaze gain, smooth pursuit, head movements, and timing of gaze relative the object were analyzed off line. Results of the five subscales included in the Bayley Scales of Infant Development (BSID-III) at 3 y of age were evaluated in relation to the visual tracking data and to perinatal risk factors. RESULTS: Significant correlations were obtained between gaze gain and cognition, receptive and expressive language, and fine motor function, respectively, also after controlling for gestational age, severe brain damage, retinopathy of prematurity, and bronchopulmonary dysplasia. CONCLUSION: This is the first study demonstrating that the basic ability to visually track a moving object at 4 mo robustly predicts neurodevelopment at 3 y of age in children born very preterm.
Subject(s)
Cognition/physiology , Developmental Disabilities/diagnosis , Pursuit, Smooth , Vision, Ocular/physiology , Bronchopulmonary Dysplasia/physiopathology , Child Development , Child, Preschool , Electrooculography/methods , Gestational Age , Humans , Infant , Infant, Extremely Premature , Infant, Premature/growth & development , Language Development , Longitudinal Studies , Psychomotor Performance , Refractive Errors/physiopathology , Regression Analysis , Risk Factors , Strabismus/physiopathologyABSTRACT
AIM: To investigate the association between perinatal risk factors and neonatal complications and early oculo-motor development in very preterm infants. METHODS: Perinatal risk factors were identified, and the potential association with early oculo-motor development was evaluated by measuring smooth pursuit eye movements (SP) at 2 and 4 months' corrected age (CA) in a population of very preterm infants born in Uppsala County 2004-2007 (n = 113). RESULTS: Among the 15 tested factors, eight showed significant association in univariate analysis with lower levels of SP at 4 months' CA, namely administration of prenatal corticosteroids, gestational age, birthweight, bronchopulmonary dysplasia, retinopathy of prematurity, periventricular leukomalacia, intraventricular haemorrhage >grade 2, and persistent ductus arteriosus. At 2 months' CA, only retinopathy of prematurity >stage 2 was associated with lower levels of SP. When all factors significant in the univariate tests were included in multiple regressions aimed to assess each factor's independent relation to SP, periventricular leukomalacia was the only significant independent factor. When adding 2-5 of the significant factors using multiple regression analysis, the levels of SP became lower. CONCLUSION: Perinatal risk factors were associated with lower levels of SP. This could be interpreted as delayed or disturbed development of normal oculomotor ability.
Subject(s)
Developmental Disabilities/physiopathology , Gestational Age , Infant, Premature, Diseases/physiopathology , Pursuit, Smooth , Analysis of Variance , Developmental Disabilities/epidemiology , Female , Follow-Up Studies , Humans , Infant , Infant, Newborn , Infant, Premature , Infant, Premature, Diseases/epidemiology , Male , Prospective Studies , Risk FactorsABSTRACT
AIM: 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. CONCLUSION: 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.
