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Associations of pre- and postnatal exposures with optic nerve status in young adults
Linna Zhu1,2, Inger Christine Munch2,3, Casper-Emil T Pedersen4
1Department of Ophthalmology, Rigshospitalet, Glostrup, Denmark.
Insights
Early life exposure to smoking is linked to thinner optic nerves and macula in young adults. This vulnerability is highest during prenatal and early childhood development.
Area of Science:
- Ophthalmology
- Developmental Biology
- Environmental Health
Background:
- The prenatal and early childhood periods are critical for optic nerve development.
- Understanding the impact of environmental exposures during these sensitive windows is crucial for long-term visual health.
Purpose of the Study:
- To investigate the effects of prenatal and postnatal exposures on optic nerve status in young adults.
- To identify specific environmental factors that may influence the developing optic nerve.
Main Methods:
- Analysis of peripapillary retinal nerve fibre layer (RNFL) thickness and macular thickness at age 18 years.
- Utilized data from the Copenhagen Prospective Studies on Asthma in Childhood 2000 (COPSAC2000) cohort.
- Correlated RNFL and macular thickness with various prenatal and childhood exposures, including maternal smoking and indoor particulate matter.
Main Results:
- Maternal smoking during pregnancy was associated with significantly thinner RNFL and macula in 18-year-olds.
- Combined prenatal and childhood tobacco smoke exposure also resulted in thinner RNFL.
- Higher indoor PM2.5 concentrations showed an association with thinner RNFL and macula in crude analyses.
- No association was found between active smoking at age 18 and RNFL or macular thickness.
Conclusions:
- Prenatal and early childhood exposure to smoking negatively impacts optic nerve and macular development.
- The optic nerve appears most vulnerable during prenatal life and early childhood, as evidenced by the lack of association with active smoking in young adulthood.
- Environmental factors during early development have lasting effects on ocular structures.
Purpose:
We aimed to explore the effect of multiple pre- and postnatal exposures on optic nerve status in young adults due to this critical period for development.
Methods:
We analysed peripapillary retinal nerve fibre layer (RNFL) status and macular thickness at age 18 years in the Copenhagen Prospective Studies on Asthma in Childhood 2000 (COPSAC2000 ) cohort in relation to several exposures.
Results:
Of the 269 participants (median (IQR) age, 17.6 (0.6) years; 124 boys), 60 participants whose mothers had smoked during pregnancy had a thinner RNFL: adjusted mean difference -4.6 μm (95% CI -7.7; -1.5 μm, p = 0.004) compared with participants whose mothers had not smoked during pregnancy. A total of 30 participants who were exposed to tobacco smoke both during foetal life and childhood had thinner RNFL: -9.6 μm (-13.4; -5.8 μm, p < 0.001). Smoking during pregnancy was also associated with a macular thickness deficit: -4.7 μm (-9.0; -0.4 μm, p = 0.03). Higher indoor concentrations of particulate matter 2.5 (PM2.5) was associated with thinner RNFL: -3.6 μm (-5.6; -1.6 μm, p < 0.001) and a macular deficit: -2.7 μm (-5.3; -0.1 μm, p = 0.04) in the crude analyses, but not in the adjusted analyses. No difference was found among participants who smoked at age 18 years compared with non-smokers on RNFL or macular thickness.
Conclusions:
We found that exposure to smoking during early life was associated with a thinner RNFL and macula at age 18 years. 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.
