Five children with a history of preterm birth (mean gestational age of 27 weeks; birth weight 870–1,380 g) and perinatal post-hemorrhagic
hydrocephalus were examined ophthalmologically at ages ranging from 4–11 years. An extended visual evoked potentials (VEPs)
examination was simultaneously performed, using pattern-reversal, motion-onset, and cognitive visual stimuli. Although 3 of
the 10 eyes displayed about normal visual acuity (≥0.9), all of the examined eyes were abnormal for at least one variant of
the tested VEPs. Pathological changes in VEPs (missing responses, shape abnormalities due to delayed VEPs maturation, prolonged
peak latencies, and reduced amplitudes) were roughly proportional to both gestational age and reduction in visual acuity.
A more severe pathology was found in the motion-onset VEPs (in all five subjects - nine eyes) when compared to the pattern-reversal
VEPs (in four subjects - eight eyes). These observations suggest that the magnocellular system/dorsal stream of the visual
pathway (which is particularly activated in response to motion stimuli) may be more frequently affected in preterm children
than the parvocellular system/ventral stream (tested mostly by the standard pattern-reversal VEPs). This pilot study may encourage
further testing of the combined pattern and motion-related VEPs examinations in preterm children as a way of detecting hidden
cortical/cerebral visual impairment (CVI).
Keywords Cortical visual impairment (CVI) - Preterm children - Visual evoked potentials - Pattern-reversal VEPs - Motion-onset VEPs