Uhlmann, et al. [10] (l99l)/Case-control study |
n=174 (each of 87 of cases and a control who had AD and were nondemented, age ≥65) |
• Visual acuity was measured using the Snellen and Rosenbaum method for far and near vision. |
• The degree of VI significantly correlated with the severity of cognitive dysfunction for both near and far vision. |
• Pure tone audiometry was performed for measuring hearing ability. |
• VI is associated with both an increased risk and an increased clinical severity of AD, but that increased risk may not be consistent with a progressive dose-response relationship. |
• The MMSE score was used as an indicator of cognitive functioning in separate analyses of demented patients. |
Lin, et al. [6] (2004)/Prospective cohort study |
n=6,112 of women (aged ≥69) |
• VI was defined as corrected vision worse than 20/40. |
• A twofold increase in the odds of cognitive and functional decline over time was associated with vision impairment. |
• HL was defined as the inability to hear a tone of 40 dB or greater at 2 kHz. |
• A trend toward increased odds of cognitive impairment for those with hearing loss at baseline was identified. |
• Cognitive and functional decline was defined as 3MS per the National Health Interview Survey Supplement on Aging. |
• Sensory impairment was associated with cognitive and functional decline in older women. |
Reyes-Ortiz, et al. [8] (2005)/Prospective cohort study |
n=2,140 of Mexican Americans (age ≥65) |
• Cognitive function decline was assessed using the MMSE-blind at baseline and at 2, 5, 7 years' follow-up. |
• Near vision impairment was predictive of cognitive decline in older Mexican Americans independently of other health factors. |
• Visual acuity was measured during an in-home interview. |
• Hearing was assessed by the HHIE. |
Lin [4] (2011)/Cross-sectional research |
n=605 (ages 60–69 year) |
• HL was defined as the pure-tone average of hearing thresholds. |
• Greater HL was significantly associated with a lower score on the DSST. |
• Cognitive function was defined by the DSST. |
• The reduction in cognitive performance associated with a 25 dB HL was equivalent to the reduction associated with an age difference of 6 years. |
• HL is independently associated with lower scores on the DSST. |
Lin, et al. [5] (2011)/Original contribution research |
n=639 (ages 36–90 year) |
• HL was defined by a PTA at 0.5-4 kHz. |
• The risk of incident all-cause dementia increases loglinearly with the severity of baseline hearing loss. |
• Incident dementia was diagnosed by a multi-disciplinary consensus diagnostic conference with the standard. |
• Hearing loss is independently associated with incident allcause dementia. |
Ong, et al. [7] (2012)/Cross-sectional study |
n=1,179 (ages 60–80 year) |
• Visual acuity was measured using the logMAR number chart. |
• Older persons with visual impairment, particularly those with visual impairment due to cataracts, are more likely to have cognitive dysfunction. |
• The Abbreviated Mental Test derived from the Hodkinson Test was used for cognitive function measurement. |
• Of the major age-related eye diseases, only diabetic retinopathy was associated with cognitive dysfunction. |
• Additionally, the major age-related eye diseases (cataracts, glaucoma, diabetic retinopathy, age-related macular degeneration) were considered to be factors for cognitive decline. |
Gurgel, et al. [3] (2014)/Longitudinal cohort research |
n=4,463 of the elderly (ages ≥65) |
• 3MS-R was used for a cognitive function comparison. |
• HL subjects have a higher rate of developing dementia and have more rapid decline than non-HL subjects. |
• HL at baseline was based on observation of hearing difficulties during testing or an interview. |
• HL was shown to be an independent predictor for developing dementia. |
• HL may be a marker for cognitive dysfunction in those 65 years (and older) elderly individuals. |
Thomson, et al. [9] (2017)/Systematic review |
n=200-1,338,462 |
• 17 studies relating HL to dementia or cognitive decline were analyzed. |
• Although the studies utilized slightly different methods to evaluate the participants, each study demonstrated that hearing loss is associated with a higher incidence of dementia in older adults. |
• The results of the studies were evaluated to determine hearing loss and cognitive status, relevant covariates and confounding factors, and a key finding. |