TOPLINE:

In a nationwide cohort of 32,316 former smokers followed up for a mean of 4.6 years, switching from combustible cigarettes to noncombustible nicotine or tobacco products was associated with a modest but consistent increase in the risk for major vision-impairing eye diseases — especially diabetic retinopathy and refractive and accommodation disorders — compared with complete abstinence from tobacco and nicotine.

METHODOLOGY:

• Researchers conducted a retrospective cohort study using data from South Korea’s public health insurance system to compare the risk for major vision-impairing eye diseases between former smokers who switched from combustible cigarettes to noncombustible nicotine or tobacco products and those who quit tobacco and nicotine entirely.
• A total of 179,273 adults who smoked combustible cigarettes in 2011-2012 and reported having quit in 2018-2019 were considered eligible for analysis. The participants were classified as those who completely quit nicotine or tobacco products (complete quitters) or those who switched to noncombustible nicotine or tobacco products (switchers).
• Researchers included 32,316 participants (mean age, 44.7 years; 97.6% male) after applying propensity score matching to balance key demographic and lifestyle characteristics, clinical factors, and comorbidities.
• Participants were followed up for up to 6 years to identify the development of major vision-impairing eye diseases, including cataract, glaucoma, age-related macular degeneration, diabetic retinopathy, and refractive and accommodation disorders. The ophthalmic disorders were identified using standard diagnostic codes.

TAKEAWAY:

• Among the matched participants followed up for a mean of 4.6 years, 6328 cases of new major vision-impairing eye disease occurred. The incidence rates were 41.1 per 1000 person-years among complete quitters and 44 per 1000 person-years among switchers.
• Switching to noncombustible nicotine or tobacco products was associated with an increased risk for major vision-impairing eye disease compared with complete cessation (adjusted subdistribution hazard ratio [SHR], 1.07; P = .005).
• The highest increases in risk were observed for diabetic retinopathy (adjusted SHR, 1.24; P = .047) and refractive and accommodation disorders (adjusted SHR, 1.07; P = .015).

IN PRACTICE:

“These findings support smoking-cessation counseling for switchers and risk awareness within routine ophthalmic care,” the researchers of the study reported.

SOURCE:

The study was led by Sangwook Cheon and Yihyun Kim, Korea University College of Medicine, Seoul, Republic of Korea. It was published online on June 13 in the American Journal of Ophthalmology.

LIMITATIONS:

Smoking and product use were self-reported, so some intermittent or dual use may have been missed. The study did not account for how long it had been since people quit smoking. The cohort was overwhelmingly male, which may have limited the generalizability of findings to women.

DISCLOSURES:

The study received support from the Institute of Information & Communications Technology Planning & Evaluation (IITP)-ICT Challenge and Advanced Network of HRD) grant funded by the Korea government (Ministry of Science and ICT; IITP-2026-RS-2024-00438263). The authors reported having no relevant financial disclosures or conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.