Prenatal smoking exposure closely associated with optic nerve abnormalities

A recent study suggests that exposure to smoking during early life is associated with a thinner retinal nerve fiber layer (RNFL) and macula at age 18, while the vulnerability of the optic nerve is highest during prenatal life and early childhood. The findings were published in Acta Ophthalmologica.

The study aimed to investigate the impact of pre- and postnatal exposures on optic nerve status in young adults. The researchers analyzed peripapillary RNFL status and macular thickness at age 18 in the Copenhagen Prospective Studies on Asthma in Childhood 2000 (COPSAC2000) cohort in relation to several exposures. 

The key findings were:

Exposure to smoking during early life, specifically in utero and during childhood, was associated with a thinner retinal nerve fiber layer (RNFL) and macula at age 18 years.

Of the 269 participants, those who were exposed to smoking during fetal life and childhood had a thinner RNFL: -9.6 μm compared to those who were not exposed.

Smoking during pregnancy was also associated with a macular thickness deficit of -4.7 μm.

Interestingly, no difference was found among participants who smoked at age 18 compared with non-smokers on RNFL or macular thickness.

In addition, higher indoor concentrations of particulate matter 2.5 (PM2.5) were associated with thinner RNFL and macular deficits in the crude analyses, but not in the adjusted analyses. However, no difference was found among participants who smoked at age 18 years compared with non-smokers on RNFL or macular thickness.

These findings highlight the importance of avoiding exposure to smoking during pregnancy and early childhood to prevent long-term damage to the optic nerve. The study also emphasizes the need for further research to better understand the underlying mechanisms of the impact of smoking on optic nerve development.

Reference:

Zhu, L., Munch, I. C., Pedersen, C., Stokholm, J., Bønnelykke, K., Chawes, B., Carlsson, C. J., Schoos, A. M., Larsen, M., Bisgaard, H., & Brustad, N. (2023). Associations of pre‐ and postnatal exposures with optic nerve status in young adults. In Acta Ophthalmologica. Wiley. https://doi.org/10.1111/aos.15657