Influence of Dementia on Vision-Related Functional Performance Among Patients With Type 2 Diabetes

Importance: Complications of Type 2 diabetes mellitus (T2DM) leading to vision loss may increase the risk of dementia. The relationship between diabetic retinopathy severity and visual acuity (VA) has been explored, but the impact of dementia on vision-related functional performance in patients with T2DM is less understood. Objective: To investigate the association of diabetes-related eye problems with dementia and the impact of dementia on vision-related quality of life (VRQoL) and activities of daily living (ADLs) in patients with T2DM. Design: Retrospective cohort and nested case-control study. Setting: Health care institution. Participants: Substudy 1 included 4,454 patients with T2DM. In Substudy 2, 33 patients with T2DM and dementia (male, n = 15; M age = 78.7 yr) were compared with 67 matched control participants (male, n = 36; M age = 76.6 yr). Outcomes and Measures: Patients with and without dementia were assessed with the 25-item National Eye Institute Visual Function Questionnaire (NEI–VFQ 25) and the Revised Self-Report Assessment of Functional Visual Performance (R–SRAFVP). Results: Substudy 1 showed a borderline significant association between proliferative diabetic retinopathy and dementia. In Substudy 2, functional vision, particularly in the overall scales and three subscales of the R–SRAFVP and four subscales of the NEI–VFQ 25, declined significantly among patients with T2DM and dementia, but no significant differences were found in VA. Conclusions and Relevance: The findings illustrate the complex relationships among T2DM, dementia, VRQoL, and vision-dependent ADL and suggest that occupational therapists who care for patients with T2DM and dementia should pay close attention to patients’ functional vision. Plain-Language Summary: Complications of Type 2 diabetes mellitus (T2DM) that lead to vision loss may increase the risk of dementia. People with T2DM and dementia show a significant decline in functional vision. This study investigated the relationship between diabetes-related eye problems and dementia as well as the impact of dementia on vision-related quality of life and activities of daily living for patients with T2DM. The study demonstrates the complex relationships among dementia, T2DM, eye conditions, and vision-related function. The results highlight the importance of a functional vision assessment for patients with T2DM and dementia. Occupational therapists who care for patients with T2DM and dementia should pay close attention to patients’ functional vision, which will guide them in assessment and intervention planning.