Visual functions in relation with neonatal cerebral ultrasound, neurology and cognitive development in very-low-birthweight children.

In order to determine the relationship between visual functions and neonatal cerebral ultrasound, neurological examinations and cognitive development, a prospective longitudinal study was conducted in 69 high-risk very-low-birthweight children. Visual development was studied at 1 and 2.6 years of corrected age by assessment of visual acuity, binocular visual fields, optokinetic nystagmus and strabismus. Visual impairments were found in 33% at age 1 and in 28% at age 2.6. Visual impairments were related to intraparenchymal damage, as detected by neonatal cerebral ultrasound, as well as to abnormal neurological examinations and lower mean developmental indices. A stepwise multiple regression analysis with neonatal cerebral ultrasound as the dependent variable and visual functions at ages 1 and 2.6 and neurological examinations at ages 1 and 2 as independent variables, however, demonstrated that standardized neurological examinations were better markers of neonatal cerebral damage than visual functions. In cognitive development at ages 1 and 2, the neurological examination at age 1 was the most important variable. In cognitive development at age 3.6, visual functions at age 2.6 were more important. Early visual impairments might thus influence later cognitive development. The effectiveness of appropriate early intervention strategies to stimulate visual and cognitive development in infants with less severe visual impairments should be subject to further study.