Dementia and glaucoma: Results from a Nationwide French Study between 2006 and 2018

Abstract Purpose Glaucoma is the leading cause of irreversible blindness worldwide. The brain and eye share many characteristics, so the eye may provide an easy‐access window on brain processes. The aim of the study was to evaluate the link between glaucoma as well as intraocular pressure (IOP)‐lowering drops load and all‐cause dementia. Methods This was a nested case‐control study based on the French national healthcare database from 1 January 2006 to 31 December 2018in individuals aged ≥60 years. We compared cases of incident all‐cause dementia with 1:5 controls matched by date of case diagnosis (index date), age, sex, and income. We set a 5‐year exposure to glaucoma period ending 2 years before the index date (lag‐time period to avoid protopathic bias). The main outcome was glaucoma defined with hospitalization related to POAG and/or dispensations of IOP‐lowering drops. The secondary outcome was the IOP‐lowering drops load. Results In total, 4810 incident all‐cause dementia and 24 050 matched controls were analysed (median [IQR] age 82 [10] years; 66.6% women). The prevalence of glaucoma was 14.0% in controls and cases. Risk of all‐cause dementia was not associated with glaucoma (crude OR, 1.02; 95% CI [0.93–1.11]; p = 0.7; adjusted OR, 0.99; 95% CI [0.91–1.09]; p = 0.9) or IOP‐lowering drops load ( p = 0.2). Conclusion The present study in general population ≥60 years old in France did not find any association between glaucoma and incident all‐cause dementia.