Abstract
Purpose: :
Motivated by pharmacologic findings linking nicotinic acetylcholine receptors to the development of myopia in chicks, we assessed whether the refractions of children passively exposed to cigarette smoke differed from those of non–exposed children.
Methods: :
A cross–sectional study was conducted in a tertiary care ophthalmology clinic by administering a questionnaire to the child’s accompanying parent. Detailed information was obtained on maternal and paternal smoking history and on risk factors for myopia and was compared to cycloplegic refractions of the children (N=323).
Results: :
Compared to the children of non–smokers, passive exposure to cigarette smoke during childhood from either parent was associated with lower myopia prevalence (12.4 vs. 25.4%; P=0.004) and more hyperopic mean (±SE) refractions (1.83±0.24 vs. 0.96±0.27 diopters; P=0.02) in their children. Smoking during pregnancy by either parent had a similar effect on a child’s refraction. The associations persisted in multivariate models that included adjustments for such parameters as parental myopia, parental education and child’s nearwork. Perhaps because of the analysis of exposure from either parent or because of the higher proportion (some 40%) of households with at least one parent smoking during the child’s lifetime in our study, these associations are considerably stronger than those in available reports from Japan and Singapore.
Conclusions: :
Neuropharmacology perspectives might prove useful for generating new hypotheses to understand the mechanisms of refractive development in children. Despite the multiple constituents of cigarette smoke, the associations of less prevalent myopia and a more hyperopic mean refraction with both prenatal and childhood exposures to cigarette smoke suggest that prenatal, non–genetic exposures may have long–term influences on refractive development and that further study of the role of nicotinic acetylcholine receptors in refractive development is warranted.
Keywords: refractive error development • clinical (human) or epidemiologic studies: risk factor assessment • myopia