Causal relationship between Alzheimer's disease and retinal nerve fiber layer thickness, visual disturbance: a two-sample Mendelian randomization study.

Abstract Alzheimer's disease (AD) is a chronic, progressive, irreversible degenerative disorder of the central nervous system caused by multiple factors.Previous studies have demonstrated that patients with AD experience visual disturbances and reduced retinal nerve fiber layer (RNFL) thickness in the early stages. If a causal relationship can be established between AD and visual disturbances as well as RNFL thickness, then AD can be diagnosed by early visual disturbances and RNFL thickness changes.To investigate the causal relationship between AD and visual disturbances as well as RNFL thickness, we conducted a Mendelian randomization study.In this MR study, the main approach was inverse variance weighted (IVW) and evaluate the robustness of the results via sensitivity analysis. The IVW results revealed no significant evidence supporting a causal association between AD and RNFL thickness (P = 0.283, odds ratio [OR] [95% confidence interval (CI)] = 0.926[0.806-1.065]) as well as visual disturbances(P = 0.205, odds ratio [OR] [95% confidence interval (CI)] = 1.070[0.964-1.187]) .Consequently, the potential for diagnosing early-stage AD through alterations in RNFL thickness and visual disturbances remains controversial.