Purpose: The main aim of the study was to evaluate which factors affect the long-time visual function in preterm children, whether it is prematurity or retinopathy of prematurity or perhaps disturbances in the visual pathway.
Materials and methods: Fifty-eight children with mean birth weight 1016 g (range 520-1500 g) were evaluated at mean age 48 months (range 42-54 months). All children underwent magnetic resonance imaging (MRI) studies, visual evoked potentials (VEPs), and the Developmental Test of Visual Perception (DTVP). The MRI evaluation included diffusion tensor imaging and fractional anisotropy (FA), and colored orientation maps were calculated for each subject. Based on the results of the VEP evaluation, children were divided into two groups: A-abnormal results of VEP (n = 16) and B-normal VEP results (comparison group, n = 42).
Results: FA values of inferior left and right occipital white matter (OWM) were lower in the group of children with abnormal VEP compared to the comparison group (0.34 ± 0.06 vs. 0.38 ± 0.06; P = 0.047; 0.31 ± 0.04 vs. 0.36 ± 0.06; P = 0.007, respectively). Furthermore, there were correlations between the latency (r = -0.35; P = 0.01) and amplitude (r = 0.31; P = 0.02) and FA in OWM. Children with abnormal VEP had lower DTVP scores as compared with children with normal VEP results (88 ± 18 vs. 95 ± 16 points, P = 0.048). Finally, a multivariate logistic regression revealed that FA of the inferior OWM was the only independent risk factor for the abnormal VEP (P = 0.04).
Conclusion: Visual perception, VEPs, and white matter microstructural abnormalities in very low birth weight children at the age of 3-4 are significantly correlated.