ABSTRACT
Purpose
In utero exposure to cigarette smoke has been suggested to result in thinner retinal nerve fibre layer (RNFL). However, the potential cofounding effects of in utero alcohol exposure and passive smoking during childhood had not been considered. We explored RNFL thickness in young adults in relation to these early life factors.
Methods
In 1989–1991, pregnant women completed questionnaires on their current smoking and alcohol drinking patterns. Following the birth of their offspring, information on household smokers was obtained between the 1- and 13-year follow-ups. At the 20-year follow-up, these offspring underwent an eye examination including optical coherence tomography imaging of the RNFL.
Results
Participants (n = 1,287) were 19–22 years old at time of eye examination. Most participants (77%) had no in utero exposure to cigarette smoke; 1.3% were initially exposed but not after 18 weeks’ gestation, while 21% had continual in utero smoking exposure. Half of the mothers never consumed alcohol or only consumed alcohol once during their pregnancies. After correcting for potential confounders, including in utero alcohel exposure and childhood passive smoking, participants who had continued in utero exposure to >10 cigarettes/day and ≤10 cigarettes/day had thinner RNFLs by 6.6 (95% confidence interval [CI] = 4.4–8.7) and 3.7 µm (95%[CI] = 2.3–5.5), respectively, than those with no exposure (p < .001). In utero alcohol exposure and childhood passive smoking were not significantly associated with RNFL thickness after accounting for in utero exposure to smoking.
Conclusions
In utero exposure to cigarette smoke is associated with thinner RFNL in young adulthood, independent of other early life environmental factors.
Acknowledgments
We would like to acknowledge Raine Study participants and their families and thank the Raine Study and Lions Eye Institute research staff for cohort coordination and data collection. The eye data collection of the Gen2 20-year follow-up of the Raine Study was funded by the Australian National Health and Medical Research Council (NHMRC) (grant no. 1021105), Ophthalmic Research Institute of Australia (ORIA), Alcon Research Institute, Lions Eye Institute, the BrightFocus Foundation, and the Australian Foundation for the Prevention of Blindness. The core management of the Raine Study is funded by The University of Western Australia, Curtin University, Telethon Kids Institute, Women and Infants Research Foundation, Edith Cowan University, Murdoch University, The University of Notre Dame Australia and the Raine Medical Research Foundation. SY and PGS are each supported by a NHMRC Early Career Fellowship. AWH and DAM are each supported by a NHMRC Practitioner Fellowship. The funding organisations had no role in the design or conduct of this research.
Disclosure Statement
The author(s) declare that they have no conflict of interest.