Purpose
Older persons with vision impairment (VI) are more likely to have cognitive dysfunction (CD). VI impacts on vision-specific quality of life (QoL). However whether CD also impacts negatively on vision-specific QoL remains unclear. We examined the association between CD and vision-specific QoL (vision-specific functioning (VF)).
Methods
We examined data from Chinese (n=1523), Malay (n=1429), and Indian (n=1350) adults aged 60 years and older who participated in three independent population based studies conducted from 2004-2012 in Singapore. Participants underwent standardized ophthalmic assessments for VI and blindness, defined using presenting visual acuity (PVA) (United States (U.S) definition). Sociodemographic data were recorded using a standardized questionnaire. CD was defined categorically i.e. absence/presence using the locally validated Abbreviated Mental Test and education-based cutoff scores. VF was measured via the psychometrically validated VF-11 questionnaire using Rasch analysis. Multivariate linear regression analysis was performed to assess the association between VF and CD, adjusting for presenting vision, major eye diseases, and other covariates.
Results
Of the 4310 participants (mean±SD age was 68.9±6.0yr; 47.7% were female) examined, 15.5% (666/4310) had CD - Chinese-10.0%, Indians-15.5%, and Malays-21.2%; p<0.001. The overall mean±SD VF score was 4.34±1.59 logits (Chinese 4.69±1.32, Indians 4.21±1.62; Malays 4.09±1.76; p<0.001), indicating a high mean level of functioning for this cohort. In multivariate linear regression models, after adjusting for age, gender, education and literacy levels, income, cardiovascular disease, total cholesterol, hypertension, and diabetes, the presence of CD was independently associated with reduced VF (β [beta coefficient] -0.61, 95%CI [confidence interval] -0.76,-0.47; p<0.05) and remained statistically significant after adjusting for unilateral VI (β -0.49, 95%CI-0.63,-0.35; p<0.05); bilateral VI (β -0.43, 95%CI -0.56,-0.29; p<0.05); and eye diseases (β -0.56, 95%CI-0.70,-0.42; p<0.05) in three separate statistical models. In models stratified by ethnicity, the association between CD and VF remained statistically significant among the three ethnic groups.
Conclusions
Older persons with CD, irrespective of their ethnicity, have reduced VF compared to people who do not have the condition. Preventing CD may contribute to better vision-related QoL.
Keywords: 669 quality of life