Retinal vascular occlusions are associated with increased risk for vascular dementia in APOE ε4 carriers in a community‐based cohort

Abstract

AbstractBackgroundWe previously reported that several eye conditions were associated with increased risks of developing Alzheimer’s disease (AD). Retinal vascular occlusions (RVO, i.e. retinal vein and artery occlusions) are one of the leading sight‐threatening retinal vascular disorders. In this study, we sought to determine whether RVO are associated with increased risks of AD and other types of dementia. A few previous studies suggest that APOE is associated with RVO and vascular dementia.MethodParticipants aged ≥ 65 and dementia‐free were recruited in a prospective, observational cohort (Adult Changes in Thought [ACT] study). Self‐reported smoking history, hypertension, congestive heart failure, diabetes, and history of cardiovascular or cerebrovascular disease were obtained at study visits, and APOE genotype was obtained from consenting participants. Cognition was evaluated every two years with extensive neurological and neuropsychological testing when cognitive scores fell below normal range. All data were reviewed at consensus conferences for diagnosis of AD and various types of dementia such as vascular dementia (VasD). Eye diagnoses were obtained using ICD‐9/10 codes. We used adjusted Cox survival models to compute hazard ratios (HR) for developing dementia.ResultA total of 4,743 participants had 1,037 incident cases of AD. 439 (9.3%) participants had retinal vascular occlusions. In participants with any APOE ε4 alleles, the HR of developing VasD was 3.03 (95%CI 1.37, 6.71, p‐value=0.0064) in participants diagnosed with retinal vascular occlusions compared to those without [Figure, Table 2]. This strong relationship persisted after further adjustment for diabetes, hypertension, and cardiovascular disease. No significant association was found between retinal vascular occlusions and VasD in participants (HR=1.05 95% CI 0.54, 2.03 , p= 0.89) who were negative for APOE ε4. No associations were found between RVO and AD or all‐cause dementia.ConclusionIncreased risk of vascular dementia was found in participants diagnosed with RVO in participants who are APOE ε4 carriers. Further research about the relationship between APOE, dementia, and eye conditions is warranted.