To evaluate the risk of developing Alzheimer disease (AD) or other dementia in patients diagnosed with open-angle glaucoma (OAG) in a nationally representative longitudinal sample of elderly persons.This retrospective cohort study (January 1, 1994-December 31, 2007) used Medicare 5% claims data. We identified beneficiaries aged 68+ years who had at least two claims with diagnoses of OAG and no Alzheimer or other dementia in 1994, using a 3-year look-back period between 1991 and 1993 (n = 63,235) and beneficiaries matched on age, sex, race, and Charlson index without a diagnosis of OAG throughout the observational period (n = 63,235), using propensity score matching. Using a Cox Proportional Hazards model, we analyzed time to AD diagnosis and time to AD or other dementia diagnosis.Elderly individuals diagnosed with OAG did not have an increased rate of AD and other dementia diagnosis compared to those without OAG during a 14-year follow-up period, even after controlling for relevant covariates present at baseline.Individuals aged 68+ years diagnosed with OAG have a decreased rate of AD or other dementia diagnosis compared to control patients without an OAG diagnosis. Although OAG and AD are both age-related neurodegenerative diseases, our findings do not support a positive association.