Prevalence of pre-stroke and stroke-related vision impairments and their association with mild cognitive impairment and dementia

Background: Vision impairment is a risk factor for mild cognitive impairment (MCI) among stroke survivors, but it is unclear if this association is driven by vision impairment present before or due to the stroke, and if similar associations exist with dementia. Objective: To (1) characterize the prevalence of pre-stroke and stroke-related vision impairment(s) among stroke survivors, and (2) quantify associations of vision impairment with dementia and cognitive impairment (MCI/dementia). Methods: Using participants from the Atherosclerosis Risk in Communities (ARIC) dataset with adjudicated incident strokes, we gathered descriptive statistics on the cohort, assessed if vision impairment was present at the time of incident stroke, and classified the impairments as pre-stroke or stroke-related. Multivariable logistic regression was used to estimate the association between these types of vision impairment and post-stroke cognitive impairment. Results: Among 233 incident stroke survivors (mean = 69 years old and 50.2% female sex), 23.2% with pre-stroke vision impairment and 18.9% with stroke-related vision impairment, there were 124 (53%) cases of cognitive impairment (n = 76 MCI, n = 48 dementia). Stroke-related vision impairment was significantly associated with higher odds of dementia (ref = normal/MCI) (adjusted odds ratio (aOR) = 2.32, 95% confidence interval (CI) = 1.08–4.92, p = 0.029), but not any cognitive impairment (ref = normal) (aOR = 1.33 95% CI = 0.67–2.70, p = 0.425). Further adjusting for stroke severity score attenuated the association of stroke-related vision impairment with dementia (aOR = 2.0, 95% CI = 0.90, 4.32, p = 0.08). Conclusions: Stroke-related vision impairment, but not pre-stroke vision impairment, was associated with higher odds of dementia. There is evidence that stroke severity could, at least partially, explain the observed association.