NPOG 2009 Abstract template

Foredragsholder / Presenter

Navn / Name: Susanne Lindqvist

Institusjon/Institution: NTNU

Avdeling / Department: Dept of Laboratory Medicine, Children's and Women's Health, Medical Faculty

Gate / Street: Teglbrennerveien 84

Post nr. / zip code: 7013 Trondheim

Land / Country: Norge

Medforfattere / Co-authors:

Navn / Name: Torgil Vangberg

Institution: University of Tromsø

Avdeling / Department: Dept of Radiology, Medical Faculty

Navn / Name: Olav Haraldseth

Institution: NTNU

Avdeling / Department: Dept of Circulation and Medical Imaging, Medical Faculty

Navn / Name: Ann-Mari Brubakk

Institution: NTNU

Avdeling / Department: Dept of Laboratory Medicine, Children's and Women's Health, Medical Faculty

Navn / Name: Torstein Vik

Institution: NTNU

Avdeling / Department: Dept of Laboratory Medicine, Children's and Women's Health, Medical Faculty

Navn / Name: Jon Skranes

Institution: NTNU

Avdeling / Department: Dept of Laboratory Medicine, Children's and Women's Health, Medical Faculty

Reduced visual acuity in preterm born adolescents related to axonal injury of corpus callosum .

Background
Visual acuity is often reduced in subjects born preterm, even in the abscence of ocular pathology. Periventricular leucomalacia (PVL) is an important risk factor for visual impairment in prematurity. However, visual impairment is also seen in ex-premature children with no PVL, and more subtle brain pathology is thought to be responsible. Diffusion tensor imaging (DTI) is an MRI technique which provides information about the microstructural organisation of cerebral white matter and is well suited to detect subtle neuronal pathology.
Objective
To assess the correlations between visual acuity and the microstructural organisation of the brain as indicated by fractional anisotropy (FA) values.
Methods
30 preterm born adolescents with very low birth weight (VLBW, < 1500g) and a control group of 45 term born adolescents, were examined at 15 years of age. Subjects underwent MRI examination including DTI. FA values were correlated to distance visual acuity using linear regression (p < 0.001, extent threshold 10 voxels).

Results
Visual acuity correlated significantly with FA values in the splenium part of the corpus callosum in VLBW subjects, but not in the control group.

Conclusions

Visual acuity correlated to FA values, a measurement of axonal integrity, in the posterior part of the corpus callosum, in adolescents with VLBW. This is, to our knowledge, the first study to prove a correlation between visual function and the structural integrity of the corpus callosum, supporting the hypothesis that slightly reduced visual acuity often encountered in ex-prematures, may be caused by subtle damage of the brain. The splenium part of the corpus callosum may be more important for normal visual development than previously acknowledged.