Vision Impairment and Adverse Health Conditions in Congolese Older People: A Population-Based Study

Introduction: In sub-Saharan Africa, many older people experience vision impairment (VI) and its adverse health outcomes. In this study, we examined separately the association between VI and each adverse health conditions (cognitive disorders, vision-related quality of life [VRQoL], and daily functioning interference [DFI]) among Congolese older people. We also explored whether VI had a significant effect on VRQoL components in our population.

Method: We performed cross-sectional analyses on data from 660 Congolese people aged ≥65 years who participated in the 2013 survey of the EPIDEMCA population-based cohort study. VI was defined as having a near visual acuity <20/40 (assessed at 30 cm using a Parinaud chart). Cognitive disorders were assessed using neuropsychological tests and neurological examinations. VRQoL was assessed using a reduced version of the National Eye Institute Visual Function Questionnaire (VFQ-22) and DFI using 11 items of participation restrictions and activity limitations. Regarding our main objective, each association was explored separately using multivariable logistic and linear regression models. Additionally, the effects of VI on each VRQoL components were explored using univariable linear regression models.

Results: VI was not associated with cognitive disorders after adjustment for residence area (adjusted odds ratio = 1.7; 95% confidence interval [CI]: 0.6; 4.7), but it was associated with a low VRQoL score (adjusted β = -12.4; 95% CI: -17.5; -7.3) even after controlling for several covariates. An interaction between VI and age (p = 0.007) was identified, and VI was associated with DFI only among people aged >73 years (adjusted β = 0.5; 95% CI: 0.2; 0.8). Our exploratory analysis showed that all components of VRQoL decreased with a decrease in visual acuity (corrected p ≤ 0.05).

Conclusion: VI was associated with poor VRQoL and high DFI. Residence area seems to play a confounding role in the association between VI and cognitive disorders. Our findings suggest that targeting interventions on vision could reduce DFI among older people and improve their well-being.