Impact of the Severities of Glaucoma on the Incidence of Subsequent Dementia: A Population-Based Cohort Study

The aim of the present study was to survey the relationship between the severity of glaucoma and subsequent dementia using the National Health Insurance Research Database (NHIRD) in Taiwan. Subjects with glaucoma were selected into the study group after an exclusion process, and each subject in the study group was propensity score-matched to another non-glaucoma patient that constituted the control group. The Cox proportional hazard regression that considered multiple potential risk factors of dementia was used to yield the adjusted hazard ratios (aHR) of dementia in different severities of glaucoma. There were 1185 (5.63 percent) subjects in the study group and 1119 (5.32 percent) patients in the control group that developed dementia. After adjusting for multiple confounders, there were no differences in the rate of any dementia (aHR: 0.961, 95% CI: 0.886-1.043, p = 0.3443), vascular dementia (aHR: 0.928, 95% CI: 0.846-1.018, p = 0.1154), Alzheimer's disease (aHR: 1.018, 95% CI: 0.761-1.362, p = 0.9025) or Parkinson's disease (aHR: 1.021, 95% CI: 0.886-1.176, p = 0.7744) between the study and the control groups. Regarding the disease severity of glaucoma, no difference was found in any type of dementia whether the glaucoma patients received less than two medical treatments, received more than two medical treatments, received drainage surgeries or received destructive surgeries. In conclusion, the different severities of glaucoma do not alter the incidence of subsequent dementia.