“Less Harmful,” E-Cigarettes Are ‘Toxic’ to Eye Health [Health Check]

[Financial News] A study has found that e-cigarettes, which are perceived as “less harmful than conventional cigarettes,” may negatively affect eye health. Among exclusive e-cigarette users, a higher level of nicotine exposure was associated with a greater likelihood of developing macular degeneration.
Although e-cigarettes are widely perceived as less harmful than conventional cigarettes, their long-term effects on eye health have not yet been sufficiently established. In particular, large-scale studies examining the relationship between e-cigarette use and age-related macular degeneration—a major retinal disease that reduces central vision with aging—remain limited.
A team led by Kim Dong Hyun, a professor of ophthalmology at Korea University Anam Hospital, recently found that among exclusive e-cigarette users, higher urinary cotinine levels tended to be associated with an increased likelihood of developing macular degeneration.
The research team analyzed 7,780 adults aged 40 or older who participated in the Korea Disease Control and Prevention Agency (KDCA)’s Korea National Health and Nutrition Examination Survey (KNHANES) from 2016 to 2021. Based on smoking history and e-cigarette use, the participants were classified into nonsmokers, former conventional-cigarette smokers, and exclusive e-cigarette users. The researchers then compared and analyzed each group’s nicotine exposure, systemic inflammation, oxidative stress levels, and other related biomarkers.
The results showed that exclusive e-cigarette users had significantly higher nicotine exposure than nonsmokers. Former conventional-cigarette smokers and exclusive e-cigarette users also had significantly higher hsCRP levels than nonsmokers, indicating greater systemic inflammation. By contrast, oxidative stress levels—which can cause damage to retinal pigment epithelial cells and retinal tissue—did not differ significantly among the groups.
The research team analyzed the relationship between nicotine exposure and macular degeneration among exclusive e-cigarette users only. The results showed a gradual increase in the likelihood of early macular degeneration as urinary cotinine concentrations, which reflect nicotine exposure in the body, rose. When cotinine concentrations were divided into three ranges, the prevalence of macular degeneration increased from 5.8% in the lowest group to 7.8% in the middle group and 8.4% in the highest group.
Kim said, “It is important to note that the study observed a trend toward a higher likelihood of macular degeneration as nicotine exposure increased among exclusive e-cigarette users.” He added, “Longer-term follow-up studies are needed to determine the long-term effects of e-cigarettes on eye health.”
He continued, “Although e-cigarettes are perceived as relatively safer than conventional cigarettes, it is necessary to examine their effects on long-term health because users may be exposed to various substances, including nicotine.”
The findings were published in the August issue of the international public health journal BMC Public Health.
 


[email protected] Medical Specialist Jung Myung-jin Reporter