Cognitive Dysfunction and the 25-Item National Eye Institute Visual Function Questionnaire

Abstract

Research Question: Do elderly individuals (ages 65 and above) with cognitive dysfunction have decreased self-reported visual function (quantified by overall National Eye Institute’s Visual Function Questionnaire (NEI VFQ) composite score) compared to elderly individuals with normal cognition? The goal of this study is to characterize the relationship between cognition (based on Mini-Mental State Examination score (MMSE)) and self-reported visual function (based on NEI VFQ-25 score), and to examine the relationship between clinical neuropsychological diagnosis (i.e., normal cognition, mild cognitive impairment, Alzheimer’s disease) and self-reported visual function.

Background, Significance, and Rationale for the Question: Cognitive dysfunction and visual impairment often coexist in the elderly population. Decreased visual function is a significant burden for these individuals and can lead to disability and decreased quality of life. Furthermore, visual impairment is associated with an increased risk of Alzheimer’s disease (AD) as well as an increased clinical severity of AD. Although visual function and cognitive impairment are interrelated, little is known about the impact of modifying treatable vision impairment on the development and progression of cognitive dysfunction. This study examines the relationship between cognition and self-reported visual function using the National Eye Institute’s Visual Function Questionnaire (NEI VFQ).

Materials and Methods: The research cohort was recruited from the Alzheimer’s Disease in Primary Care (ADPC) study at UNTHSC. The participants completed the Mini-Mental State Examination (MMSE) for assessment of cognition, as well as the National Eye Institute’s Visual Function Questionnaire (NEI VFQ) to assess self-reported visual function. Additionally, as a part of the ongoing ADPC study, participants underwent rigorous neuropsychological testing and were assigned a clinical consensus diagnosis based on established criteria. Statistical analyses of the data included a general linear model and an analysis of variance approach to compare means between multiple groups.

Results: The data revealed a statistically significant association between overall composite score on the NEI VFQ and the total MMSE score (P = 0.04). On average, for every 1-point increase in MMSE score, the overall composite NEI VFQ score increased by 0.40 units (95% confidence interval: 0.03 – 0.77).

Conclusions: Reduced visual function should raise concern for cognitive decline and prompt additional assessment. Implementation of screening tools such as the NEI VFQ could help to identify modifiable causes of visual impairment and thus have the potential to impact cognition.