Effects of maternal occupational exposure to organic solvents on offspring visual functioning: A prospective controlled study

Background: Previous studies in adults and animals with high level exposure to organic solvents suggested impairments in visual functioning. The objective of this pilot study was to examine the effects of maternal occupational exposure to organic solvents during pregnancy on offspring color vision and visual acuity, the development of which may be especially vulnerable to organic solvent exposure. Methods: We conducted a prospective cohort study of 32 offspring of women who were exposed occupationally to organic solvents during pregnancy compared with 27 nonexposed children. Monocular and binocular color vision and visual acuity were assessed using the Minimalist Test and the Cardiff Cards, respectively. Children with known hereditary color vision loss were excluded. Results: Solvent-exposed children had significantly higher error scores on red-green and blue-yellow color discrimination, as well as poorer visual acuity compared with the control group. Exposure index (an estimated measure of exposure intensity) was not significantly related to color discrimination or visual acuity score. Despite excluding all children with a known family history of color vision loss, clinical red-green color vision loss was found among 3 of the 32 exposed children compared with none of the matched controls. Conclusions: These preliminary findings suggest that occupational exposure to organic solvents during pregnancy is associated with an increased risk of color vision and visual acuity impairment in offspring. The importance of routine visual function screening in risk assessment after prenatal exposure to chemicals warrants further attention.