Reported in Investigative Ophthalmology & Visual Science (Smoking and Risk of Age-related Cataract: A Meta-analysis), the new findings are the result of a meta-analysis conducted by a team of researchers from China.
The team performed the analysis using 12 cohorts and eight case-control studies from Africa, Asia, Australia, Europe and North America, to compare the prevalence of age-related cataract in individuals who ever smoked cigarettes to those who have never smoked. Further subgroup analyses were performed based on the subjects’ status as a past or current smoker and the three subtypes of age-related cataract.
The results showed that every individual that ever smoked cigarettes was associated with an increased risk of age-related cataract, with a higher risk of incidence in current smokers. In the subgroup analysis, former and current smokers showed a positive association with two of the subtypes: nuclear cataract, when the clouding is in the central nucleus of the eye, and subscapular cataract, when the clouding is in the rear of the lens capsule.
The analysis found no association between smoking and cortical cataract, in which the cloudiness affects the cortex of the lens.