Smoking and Risk of Age-Related Cataract
The authors of the following study conducted a meta-analysis to evaluate the relationship between smoking and age-related cataract. They identified eligible studies via both computer searches and reviewing the references lists of the key articles.
They also calculated the summary relative risk ratio (RR) or odds ratio (OR) and 95% confidence interval (CI). Additionally, the authors pooled study-specific risk estimates using a random-effects model and performed meta-regression to assess for heterogeneity by several covariates and subgroup analysis on ARC types.
A total of 13 prospective cohort and eight case-control studies met their inclusion criteria. The study authors found that ever smoking was statistically significant associated with increased risk of ARC among cohort studies (OR, 1.41; 95% CI, 1.23–1.62) and case-control studies (OR, 1.57; 95% CI, 1.20–2.07). Furthermore, in subgroup analysis, ever smoking exhibited a positive relationship with nuclear cataract (OR, 1.66; 95% CI, 1.46–1.89) and a marginally signiﬁcant relationship with posterior subcapsular cataract (OR, 1.43; 95% CI, 0.99–2.07) in cohort studies. The authors found similar results in case-control studies (nuclear cataract, OR, 1.86; 95% CI, 1.47–2.36; posterior subcapsular cataract OR 1.60; 95% CI, 0.97-2.65). Current smokers were at higher risk of ARC than past smokers. They observed no association between smoking and cortical cataract.
The overall current literature suggested that smoking was associated with increased risk of ARC, especially nuclear cataract (NC). Further efforts should be made to confirm these findings and clarify the underlying biological mechanisms.