Is Allopurinol Associated with Cataracts?

A controversy discussed periodically in the ophthalmology literature, but little known to primary care physicians, is whether allopurinol causes cataracts. These researchers used a Quebec provincial database to examine this association in persons aged 65 and over.

The study compared 3,677 patients with cataract extractions and 21,868 controls. After adjusting for age, sex, diabetes, hypertension, steroid use, and glaucoma, there were significant associations between cataract extraction and use of allopurinol for more than three years (odds ratio, 1.53) or ingestion of a cumulative dose over 400,000 mg (OR, 1.82). These associations were even stronger in patients who became new allopurinol users after the database was developed (OR, 2.34 and …