Low Birth Weight Babies and Risk for Visual Impairment
Preterm infants with smaller occipital brain volumes are more likely to experience impaired visual function in early childhood according to a study published in the August 2006 issue of Investigative Ophthalmology & Visual Science (IOVS).
The study followed 68 infants in New Zealand who were born between 23 and 33 weeks' gestation. At term equivalent, all study infants underwent magnetic resonance imaging to measure occipital regional brain volumes.
Thirty-five percent of the infants were later found to have abnormal oculomotor control, including impaired saccades and binocular eye alignment, at two years of age. Compared with preterm infants without impaired visual performance, the study infants with visual impairments had significantly smaller inferior occipital region brain tissue volumes.
Divyen K. Shah, MB, ChB, of Royal Children's Hospital, Murdoch Children's Research Institute in Melbourne, Australia, who led the study says, "This study is amongst the first published to link alterations in specific brain regional volumes of the visual pathway with impaired functioning in childhood for prematurely born infants. These findings help us to identify where and what is different in prematurely born infants. Such measurements could be done on an MRI scan at discharge from the neonatal unit identifying children with higher risk for later visual challenges."