Overview
Age-related vision impairment and dementia both become more prevalent with increasing age. Research into the mechanisms of these conditions has proposed that some of their causes (e.g., macular degeneration/glaucoma and Alzheimer's disease) could be symptoms of an underlying common cause, or may be equally linked to a multifactorial context in frailty and aging. Research into sensory-cognitive aging has provided preliminary data that sensory decline may be linked to the progression of dementia through the concept of sensory deprivation. Preliminary data in hearing loss rehabilitation support the idea that improved hearing may have a beneficial effect on cognitive functioning; however, there are to date no data available to examine whether low vision rehabilitation, specifically for reading, could have an equally protective or beneficial effect on cognitive health. The present proposal aims to fill this gap.
Description
The research questions are the following:
- Does low vision rehabilitation reduce reading effort?
- If so, does reduced reading effort increase reading activity,
- If so, does increased reading activity improve cognitive (memory) functioning?
The objectives are to:
- Evaluate cognitive functioning and memory before, and 6 and 12 months after low vision reading rehabilitation using magnification in patients with age-related macular degeneration or glaucoma, compared to age-matched visually impaired controls who undergo rehabilitation that is NOT related to reading (e.g., mobility)
- Correlate participant characteristics with all cognitive outcome variables in order to identify potential mediators, moderators or confounders Hypotheses
- Measures of reading (subjective and objective effort) will be statistically significantly reduced after participants have received strategies and tools to facilitate reading.
- Measures of reading behaviour will be negatively correlated with measures of reading effort (e.g., participants who report less effort will read more, more frequently and for longer)
- Individuals that demonstrate reduced reading effort/improved reading behaviour will demonstrate improved scores on cognitive tests after 6 months of having received rehabilitation strategies and tools, compared to those whose reading effort remains high or whose reading behaviour remains unchanged. These beneficial effects will be maintained after 12 months.
Methodology
Study Design: The study utilizes a quasi-experimental approach (nonrandomized, pre-post intervention study), an approach frequently used during the evaluation of health interventions. Specifically, a 2x3 design (2 groups x 3 time points) will allow for the examination of whether cognitive performance will change before and after 6 and 12 months of a low vision reading intervention, when comparing low vision patients to age-matched controls. Participants will also be audio-recorded throughout several of the tasks to not only ensure the highest level of precision when inputting and analyzing data, but will also help reduce the overall testing time.
Eligibility
Inclusion Criteria:
- Able to communicate in either English or French
- Impairment of central vision, affecting acuity due to any diagnosis
- Visual acuity in the better eye with best standard correction of 20/60 or less
- Potential benefit from magnification or other reading rehabilitation interventions, as determined by rehabilitation professional.
- Client dossier with one of the partnering rehabilitation agencies.
Exclusion Criteria:
- Complete blindness
- Inability to communicate verbally
- Inability to independently give informed written consent