Statin use and risk for cataract: a nested case-control study of 2 populations in Canada and the United States.
BACKGROUND
In current literature the association between statin use and cataracts is inconsistent and controversial. We sought to further examine the effect of statin use on the risk of cataract and need for surgical intervention in 2 North American populations.


METHODS
This retrospective nested case-control study derived data from the British Columbia (BC) Ministry of Health databases from 2000-2007 and the IMS LifeLink database from 2001-2011 to form 2 patient cohorts. The BC cohort was comprised of female and male patients; 162,501 patients were matched with 650,004 control subjects. The IMS LifeLink cohort was comprised of male patients aged 40-85 years; 45,065 patients were matched with 450,650 control subjects. Patients with statin use for > 1 year before the initial ophthalmology visit were identified. Diagnosis and surgical management of cataract were followed. Conditional logistic regression models were used to analyze data.


RESULTS
For the BC cohort, the crude rate ratio (RR) for use of any statin was 1.30, and the adjusted RR was 1.27 (95% confidence interval, 1.24-1.30). The adjusted RRs for each individual statin were all statistically significant. For the IMS LifeLink cohort, the crude RR for use of any statin was 1.13, and the adjusted RR was 1.07 (95% confidence interval, 1.04-1.10).


CONCLUSIONS
This study demonstrates that statin use is significantly associated with cataract requiring surgical intervention. This relationship was consistent in both North American cohorts. Further assessment of this relationship is recommended, especially because of increased statin use and the importance of acceptable vision in old age when cardiovascular disease is common.