Nonarteritic Anterior Ischemic Optic Neuropathy and the Risk of Dementia: A Nationwide Cohort Study.

Background And Objectives: While emerging theories suggest that vascular dysfunction may occur concurrently with the amyloid cascade in Alzheimer disease (AD) pathogenesis, the role of vascular components as primary neurodegeneration triggers remains uncertain. The aim of this retrospective, population-based cohort study conducted in Korea was to explore the link between nonarteritic anterior ischemic optic neuropathy (NAION) and dementia risk.

Methods: In this nationwide, population-based, retrospective cohort study, we identified newly diagnosed NAION from 2010 to 2017 in the Korean National Health Insurance Service database. The primary outcome was new dementia diagnoses confirmed by new claims coupled with antidementia medication prescriptions. We assessed dementia risk using hazard ratios (HRs) with 95% CIs over an average 2.69-year follow-up after a 1-year lag period.

Results: The cohort consisted of 42,943 patients with NAION and 214,715 age-matched and sex-matched controls without NAION (mean age 61.37 years ± 10.75 SD, 55.48% female). The study found a higher risk of all-cause dementia (ACD; HR 1.28, 95% CI 1.20-1.36), AD (HR 1.27, 95% CI 1.18-1.36), vascular dementia (VaD; HR 1.31, 95% CI 1.09-1.58), and other dementia (HR 1.39, 95% CI 1.11-1.73) among patients with NAION, regardless of other potential confounding factors such as age, sex, lifestyle behaviors, economic status, and preexisting health conditions. In subgroup analysis, the associations between NAION and ACD were stronger in the younger age group (HR 1.83 for those younger than 65 years vs 1.23 for those 65 years or older; for interaction <0.001). Moreover, the association of NAION with both ACD and VaD was particularly strong among current smokers.

Discussion: We found a significant association between NAION and increased risk for ACD, AD, VaD, and other dementia even after adjusting for potential confounders such as lifestyle, health conditions, and demographic factors within a nationwide cohort. This study highlights the potential role of vascular pathology in dementia progression and suggests that NAION may serve as a robust predictor for dementia, highlighting the need for comprehensive neurologic assessment in patients with NAION. Further research is needed to clarify the association between NAION and dementia risk.