New study suggests patients are most susceptible to side effects from smoking exposure during the earliest years of their lives. Photo: Getty Images.

A smoking habit is well-known to bring with it numerous health risks, ocular ones included. Recent research aiming to explore the effects of multiple pre- and postnatal exposures on optic nerve status in young adults found that exposure to smoking during early life was associated with a thinner retinal nerve fiber layer (RNFL) and macula at 18 years of age.

The study included 269 participants and analyzed the peripapillary RNFL status and macular thickness at age 18 in each.

Of the cohort, 60 participants (22.3%) whose mothers had smoked during pregnancy had a thinner RNFL (-4.6μm). A total of 30 participants (11.2%) who were exposed to tobacco smoke both during fetal life and childhood had a thinner RNFL (-9.6μm). Smoking during pregnancy was also associated with a macular thickness deficit (-4.7μm). Higher indoor concentrations of particulate matter 2.5 were associated with a thinner RNFL (-3.6μm) and a macular deficit (-2.7μm) in the crude analyses but not in the adjusted analyses. No difference in RNFL or macular thickness was found among participants who smoked at age 18 compared with non-smokers.

“The absence of an association between active smoking at 18 years suggests that the vulnerability of the optic nerve is highest during prenatal life and early childhood,” the study authors concluded in their paper.