Just like traditional cigarettes, e-cigs may present a risk for visual impairment and ocular issues.  Photo: Getty Images.

Tobacco smoking increases health risks and the chances of many diseases, including several ocular diseases such as cataracts and thyroid eye disease. Less is known about the effects of tobacco-free alternative e-cigarettes, however. Looking to bridge this gap, researchers recently analyzed over 1.1 million responses from adults aged 18 and older from the Behavioral Risk Factor Surveillance System to study the association between e-cigarette smoking and perceived visual impairment.

The study concluded there is an association between e-cigarette use and increased visual impairment. When it comes to age, younger people used e-cigarettes more often and older people had higher odds of visual impairment, with a relatively consistent association of e-cigarette use on visual impairment across the board.

A previous study showed a correlation between e-cigarette use and increased symptomatic dry eye and decreased tear film, theorizing that “the propylene glycol used as solvent for the e-cigarette liquid produces free radicals which damage the lipid layer of the tear film by lipid peroxidation.”

In this study, e-cigarette users were found to have lower tear meniscus heights and tear breakup times, “which were thought to be from deterioration of the lipid layer, but normal to elevated Schirmer testing indicated increased reflex tearing,” the authors noted.

Even though e-cigarettes don’t contain tobacco, they share similarities with cigarettes. “Firstly, e-cigarettes have been shown to create oxidative stress and decrease antioxidants. Oxidative stress and reduction in antioxidants have been implicated in the development of cataracts, age-related macular degeneration and even glaucoma,” the authors explained in their study. “Secondly, e-cigarettes also contain nicotine, which has been implicated in vasoconstriction in the eye and may increase the risk for glaucoma via vasoconstriction of episcleral veins or arteries supplying the optic nerve.”

While e-cigarette use is associated with increased prevalence of vision impairment, the authors suggest a longitudinal, observational study should be conducted to further investigate this association.