Primary open‐angle glaucoma and its relationship with smoking: A systematic review and meta‐analysis.

Aims/Purpose: Glaucoma is one of the major global causes of irreversible blindness. Numerous studies have investigated the relationship between smoking and (the risk of developing) primary open‐angle glaucoma (POAG), yet two prior meta‐analyses have reported contradictory findings. Consequently, the objective of this review is to provide a comprehensive update regarding the correlation between smoking and the occurrence of POAG. Methods: This systematic review was registered on PROSPERO, ID: CRD42023409440. A comprehensive search was carried out on EMBASE, MEDLINE, and Web of Science databases, encompassing articles published up until May 2023. The inclusion criteria comprised studies that provided a statistical analysis exploring the association between smoking and primary open‐angle glaucoma (POAG) in adult populations. After eliminating duplicate entries, 1596 articles were subjected to initial screening based on their titles and abstracts, of which 148 articles underwent full text screening. Data were extracted by two independent authors, and meta‐analyses were completed using Revman (version 5.4) software. Results: A total of 30 studies met the inclusion criteria, encompassing cohort, case–control and cross‐sectional studies. The combined participant population across these studies was estimated to be approximately 300 000, with over 7300 cases of POAG. The results of the meta‐analysis revealed that individuals classified as current smokers, past smokers, as well as those who had both current and past smoking histories exhibited no statistically significant association with the occurrence of POAG when compared to individuals who had never smoked. Conclusions: Our meta‐analysis provides evidence to suggest that there is no causal relationship between smoking and primary open‐angle glaucoma (POAG). However, considering the detrimental effects of smoking on ocular health, it remains imperative to advise patients on smoking cessation. [ABSTRACT FROM AUTHOR]