Clinical Review

Experiencing Age-Related Vision and Hearing Impairment: The Psychosocial Dimension


 

References

It should also be mentioned in this context that assessment strategies have been developed to better consider the specific life conditions of those with vision and hearing impairment. The best-known and frequently applied instruments in this context are the National Eye Institute Visual Function Questionnaire [30] and the Hearing Handicap Inventory for the Elderly [31].

Cognitive Functioning

Previous research largely supports the notion that reduced vision and hearing function is accompanied by a decrease in cognitive performance in older adults. The work of Lindenberger and Baltes, based on the Berlin Aging Study (BASE)—but also including additional studies with a wider age-range—is central in supporting a strong connection among vision, hearing, balance, and cognitive functioning in later life. Lindenberger and Baltes [32] found that general intelligence correlated just as strongly with visual as with auditory ability. In a model conjoining age, sensory function, as well as intelligence, visual and auditory function predicted a large portion of interindividual differences in intelligence and indeed fully mediated the negative correlation between age and intelligence. This finding has meanwhile been replicated by a number of other research groups and may be regarded as rather robust [33,34]. In addition, Baltes and Lindenberger [35] observed that sensory measures were better predictors of intelligence than socio-structural variables such as education or social class. They also showed that the connection among sensory functioning and intelligence was much closer in older adults as compared to adults in early and middle adulthood [34].

No clear difference between the sensory modalities of vision and hearing has been identified regarding their relationship with cognitive performance. On the one hand, there is research supporting the view that both vision and hearing impairment are connected with cognitive decline [12,36,37], while some evidence also supports that the linkage may be stronger with vision [14]. On the other hand, there are also data not supporting a close connection between vision and hearing impairment and cognitive function [38]. Explanations for such inconsistencies may refer to a number of reasons, such as pronounced positive selectivity of samples (which may lead to underestimation of connections among sensory and cognitive function), the application of established cognitive tests not appropriate for sensory impaired older adults (which may lead to overestimation of connections among sensory and cognitive function), and the application of different cut-off scores for significant vision and hearing impairment (possibly, higher cut-offs may lead to higher, lower to lower connections). Longitudinal data using the latest in causal modeling data analysis support the view that the causal dynamics involved in sensory and intelligence change are complex and that each of these variables can drive change in the other across longer periods of later life [39].

Vision status also plays a role when it comes to the connection between cognitive function and everyday competence—a linkage that is generally challenged as people age and that may lead to endpoints such as dependence on others and transition to long-term care. Heyl et al [40] observed that the link between vision status and out-of-home leisure activities is mediated by cognitive status. In a more recent study, able to add to the understanding of such a mediation process, Heyl and Wahl [38,41] showed that the connection between cognitive function and everyday function is much closer in visually and hearing impaired older adults as compared with visually unimpaired older adults, which possibly means that both visually and hearing impaired elders rely more intensely on their cognitive resources. Causality dynamics may however also work in the opposite direction. As Rovner and colleagues [42,43] observed in a study with age-related macular degeneration patients over 64 years of age covering a 3-year observation period and 2 measurement occasions, activity loss over time due to the visual loss led to cognitive decline happening between T1 and T2. This finding fits well with the more general finding in the cognitive aging literature that the exertion of social and leisure activities is important for maintaining cognitive functioning [44].

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