Smoking and the risk of dry eye: a Meta-analysis

AIM: To collect the evidence to estimate the correlation between smoking and the incidence of dry eye.METHODS: The PubMed, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL, last issue), CBM (Chinese BioMedical Literature Database), and CNKI (China National Knowledge Infrastructure/Chinese Academic Journals full-text Database) were searched for eligible studies published from January 1964 to December 2015 to investigate the association of smoking with the risk of dry eye. The odds ratio (OR) and 95% confidence interval (CI) were summarized and calculated. The extracted studies were pooled by the fixed-effects model or a random-effects model.RESULTS: Two cohort studies and eight cross-sectional surveys were included in our Meta-analysis. There was no statistically significant relationship between current (OR=1.32; 95% CI: 0.99-1.76; P=0.055) or ever smoking (OR=1.12; 95% CI: 0.98-1.28; P=0.107) and the risk of dry eye among the studies, even when age and gender were adjusted (OR=1.16; 95% CI: 0.83-1.64; P=0.383). In the sensitivity analysis in which only general population were included, the association was significant between smoking and dry eye (OR=1.50; 95% CI: 1.08-2.09; P=0.016).CONCLUSION: This Meta-analysis suggests that smoking may associate with the risk of dry eye in general population.