TY - JOUR
T1 - Vision abnormalities in young children exposed prenatally to organic solvents
AU - Till, Christine
AU - Westall, Carol A.
AU - Koren, Gideon
AU - Nulman, Irena
AU - Rovet, Joanne F.
N1 - Funding Information:
This research study, which was conducted in partial fulfillment of Christine Till's doctoral thesis, was presented at the 21st International Neurotoxicology Conference in Hawaii. Christine Till was the recipient of the Pre-Doctoral Student Poster Award. This study was funded by the Workers Safety Insurance Board (WSIB), Canadian Institute for Health Research (CIHR) and the Vision Science Research Program. Gideon Koren is a Senior Scientist of the CIHR and a holder of the Ivey Chair in Molecular Toxicology, University of Western Ontario. The authors thank Jose Vega, Nidhi Lodha, Tom Wright, and Giuseppe Mirabella for technical assistance, Sarah Swartz and Laura Kenton for recruiting and assisting with testing, and Sharon Morong for conducting VEP reliability measurements. We also thank the Motherisk Program at HSC from which we recruited all participants. Finally, we are indebted to all of the mothers and their children for participating in the study.
PY - 2005/8
Y1 - 2005/8
N2 - Despite an accumulating body of evidence demonstrating that the visual system is an important target for organic solvent toxicity in adults, little attention has been paid to the visual functioning of children with prenatal exposure to organic solvents. The present study aimed to: (1) determine prospectively whether prenatal solvent exposure increases the risk of visual deficits in infants and (2) assess the relationship between estimates of exposure level and integrity of visual responses. A sample of 21 infants born to women who were occupationally exposed to solvents during pregnancy was compared with 27 non-exposed age-matched control infants. All mothers were recruited from Motherisk, an antenatal counseling service in Toronto, Canada. Contrast sensitivity and grating acuity were assessed using a sweep visual evoked potential (VEP) technique whereas chromatic- and achromatic mechanisms were assessed using a transient VEP technique. Exposure level was estimated from questionnaire data obtained during pregnancy. Testers were masked to exposure status. Results showed a significant reduction in contrast sensitivity in the low and intermediate spatial frequency range in solvent-exposed infants compared to controls (p < 0.001). With respect to grating acuity, there was a significant effect of exposure level, with children in the high exposed having reduced grating acuity compared with children in the low exposed group (p < 0.025) and controls (p = 0.02). Regarding color vision, 26.3% of infants in the exposed group versus 0% of the controls produced abnormal VEP responses to the red-green onset stimulus (p < 0.01), but not to either blue-yellow or achromatic stimuli. No differences were found with respect to latency or amplitude of chromatic and achromatic response. These findings suggest that prenatal solvent exposure is associated with selective visual deficits, including reduced contrast sensitivity and abnormal red-green vision. Increasing levels of exposure may lead to further visual deficits affecting grating acuity. These findings support the need for a re-evaluation of current occupational exposure standards for pregnant women.
AB - Despite an accumulating body of evidence demonstrating that the visual system is an important target for organic solvent toxicity in adults, little attention has been paid to the visual functioning of children with prenatal exposure to organic solvents. The present study aimed to: (1) determine prospectively whether prenatal solvent exposure increases the risk of visual deficits in infants and (2) assess the relationship between estimates of exposure level and integrity of visual responses. A sample of 21 infants born to women who were occupationally exposed to solvents during pregnancy was compared with 27 non-exposed age-matched control infants. All mothers were recruited from Motherisk, an antenatal counseling service in Toronto, Canada. Contrast sensitivity and grating acuity were assessed using a sweep visual evoked potential (VEP) technique whereas chromatic- and achromatic mechanisms were assessed using a transient VEP technique. Exposure level was estimated from questionnaire data obtained during pregnancy. Testers were masked to exposure status. Results showed a significant reduction in contrast sensitivity in the low and intermediate spatial frequency range in solvent-exposed infants compared to controls (p < 0.001). With respect to grating acuity, there was a significant effect of exposure level, with children in the high exposed having reduced grating acuity compared with children in the low exposed group (p < 0.025) and controls (p = 0.02). Regarding color vision, 26.3% of infants in the exposed group versus 0% of the controls produced abnormal VEP responses to the red-green onset stimulus (p < 0.01), but not to either blue-yellow or achromatic stimuli. No differences were found with respect to latency or amplitude of chromatic and achromatic response. These findings suggest that prenatal solvent exposure is associated with selective visual deficits, including reduced contrast sensitivity and abnormal red-green vision. Increasing levels of exposure may lead to further visual deficits affecting grating acuity. These findings support the need for a re-evaluation of current occupational exposure standards for pregnant women.
KW - Color vision
KW - Contrast sensitivity
KW - Organic solvents
KW - Prenatal exposure
KW - Visual evoked potentials
UR - http://www.scopus.com/inward/record.url?scp=23844484249&partnerID=8YFLogxK
U2 - 10.1016/j.neuro.2005.05.011
DO - 10.1016/j.neuro.2005.05.011
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C2 - 16054697
AN - SCOPUS:23844484249
SN - 0161-813X
VL - 26
SP - 599
EP - 613
JO - NeuroToxicology
JF - NeuroToxicology
IS - 4 SPEC. ISS.
ER -