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William V. Good, Chuan Hou, Anthony Norcia; A Comparison of Visuocortical Function in Premature Infants with Grade I/II and Grade III/IV Intraventricular Hemorrhage. Invest. Ophthalmol. Vis. Sci. 2012;53(14):5639.
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© ARVO (1962-2015); The Authors (2016-present)
Infants born prematurely with intraventricular hemorrhage (IVH) are at high risk for visual deficits. However, early quantitative measurements of vision function for this group of patients are scant. Here, the quantitative swept parameter Visual Evoked Potential (sVEP) responses evoked by three different visual stimuli were measured in a cohort of preterm infants with IVH. sVEP responses of infants with IVH Grade I/II were compared with those of infants with Grade III/IV.
38 preterm infants with IVH participated in the study. 27 had Grade I/II and 11 had Grade III/IV. Enrolled infants were between 24 and 32 weeks gestational age, with birth weights less than 1500 g. Spatial frequency, contrast, and vernier offset sweep VEP tuning functions were measured at 5 to 7 months’ corrected age. Thresholds for sVEP responses for three stimuli were derived by extrapolating the tuning functions to 0 amplitude. Both thresholds and suprathreshold response amplitudes were compared for the two groups.
Mean sVEP suprathreshold response amplitudes in infants with Grade III/IV IVH were lower than that found in infants with Grade I/II IVH for all three measures. The number of infants with measurable thresholds was substantially lower for all 3 measures (spatial frequency sVEP: 13 of 14 for Grade I/II and 6 of 9 for Grade III/IV; contrast sVEP, 24 of 27 for Grade I/II and 5 of 11 for Grade III/IV; and for vernier acuity, 20 of 25 for Grade I/II and 6 of 9 for Grade III/IV).
When measured at 5-7 months, preterm infants with grade III and IV IVH had measurable and significant changes in cortical responsiveness compared with infants with Grade I and II IVH. These results suggest that sVEP could be useful for early quantitative measurements for vision function and neural processing in premature infants with IVH.
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