Tobacco smoking is not associated with primary open-angle glaucoma: a systematic review and meta-analysis

PURPOSE: This systematic review explores the relationship between tobacco smoking and the development of primary open-angle glaucoma (POAG). Glaucoma is the leading cause of irreversible blindness worldwide. Prior literature investigating the link between tobacco smoking and glaucoma has reported contradictory findings on the association between tobacco smoking and POAG. METHODS: Systematically EMBASE, MEDLINE, and Web of Science were searched, encompassing articles published up until April 2025. The inclusion criteria comprised observational and randomised controlled studies that provided a statistical analysis exploring the association between tobacco smoking and POAG in adult populations. The ROBINS-E tool was utilised to assess the risk of bias of studies and meta-analyses were completed using RevMan software. The main outcomes were effect estimates that measured the association between tobacco smoking and POAG. RESULTS: Across 26 eligible studies and 289,930 participants, there was a prevalence of 6,454 cases of POAG. The meta-analyses revealed that current smokers (OR = 1.00, 95%CI 0.76-1.33, p = 0.97, n = 11), past smokers (OR = 0.92, 95%CI 0.75-1.11, p = 0.38, n = 6) as well as both current and past tobacco smoking combined (OR = 1.00, 95%CI 0.84-1.19, p = 1.00, n = 17) exhibited no statistically significant association with POAG when compared to individuals who had never smoked. Heterogeneity ranged from low to substantial across comparisons, and risk of bias was frequently rated as high among included observational studies. The lack of an associative effect was sustained, on exclusion of studies with a high risk of bias. CONCLUSION: Although the results suggest no significant statistical association between tobacco smoking and POAG, given the substantial morbidity and mortality associated with tobacco smoking and the detrimental impact on systemic and ocular health, tobacco smoking cessation should remain at the forefront of health promotion. PROSPERO registration ID: CRD42023409440.