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
The fact that X-rays can induce mutation was established first in 1927. In the years following the mutagenic effects of some rays were described. When DNA was identified as the universal genetic material, it soon became obvious, and was confirmed by genetic evidence that the genetic material of all living beings is susceptible to radiation induced damage. When DNA is damaged by radiation enzymes within the cell nucleus attemp to repair that damage. If repair does not suceed or not correctly, the cell may die or may suffer changes in genetic information. It is thought that killing of cells is the basis for deterministic effect and that subtlechanges in information are important in the development of radiation-induced cancer or of genetic effects if these changes are induced in germ cells. This document describes aspects such as biological effects of ionizing radiation (deterministic radiation effects); stochastic radiation effect and quantification of risk; somatic effects; genetic effects of the ionizing radiation
