Exposure to Smoking and Alcohol, and Passive Smoking during Childhood: Effect on the Retinal Nerve Fibre Layer in Young Adulthood.

Purpose: exposure to cigarette smoke has been suggested to result in thinner retinal nerve fibre layer (RNFL). However, the potential cofounding effects of 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 exposure to cigarette smoke; 1.3% were initially exposed but not after 18 weeks' gestation, while 21% had continual smoking exposure. Half of the mothers never consumed alcohol or only consumed alcohol once during their pregnancies. After correcting for potential confounders, including alcohel exposure and childhood passive smoking, participants who had continued 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 ( < .001). alcohol exposure and childhood passive smoking were not significantly associated with RNFL thickness after accounting for exposure to smoking.

Conclusions: exposure to cigarette smoke is associated with thinner RFNL in young adulthood, independent of other early life environmental factors.