‘Watch your step’- Why it’s important to assess vision for falls prevention?
Mrs Jignasa (Jigs) Mehta is a Dunhill Medical Trust Fellow researching visual impairment in falls and fear of falling and a lecturer in the Directorate of Orthoptics and Vision Science at the University of Liverpool. Follow on Twitter via @JigsMehta1 @BIOSFallsSIG
A briefing paper published by the RNIB estimated that the cost of falls associated with sight loss to the NHS is £25.1 million per year.
Try balancing on one leg with your eyes closed - tricky isn’t it? We know that we need the right input from the visual, proprioceptive and somatosensory systems to stay on our feet. NICE guidance (2013) clearly states that the multifactorial assessment should include an assessment of visual impairment. There has been progress in raising the importance of vision assessment in falls patients with the introduction of tools such as the RCP ‘Lookout Bedside vision check’ tool and the Thomas Pocklington ‘Eye Right Toolkit’ but the NICE impact report on falls and fragility fractures highlighted that ‘fewer than half of falls patients had a documented assessment of their vision’.
Perhaps the problem is that we’re not sure what a ‘good’ visual assessment looks like? Reduced visual functions such as visual acuity, contrast sensitivity, depth perception and visual fields have all been shown to be associated with increased risk of falls. Depth perception can potentially be an issue when negotiating that ‘step’ or ‘kerb’ if there is a difference in visual acuity between each eye or misalignment of the eyes. Currently as part of my fellowship, I am undertaking an age-matched case control study to identify key visual functions that are risk factors in falls, taking into account confounding factors such as number of medications, co-morbidities, balance and social demographics. In addition, using qualitative methodology I will be exploring the fear of falling in people who have a visual impairment to understand their perception of risk of falls so we can better understand how to mitigate that fear and allow them to remain active whilst coping with a visual impairment.
Our ageing population will see an increase in age-related visual impairment such as AMD and glaucoma, and therefore an associated decline in visual function. However we must not forget those that may have correctable visual impairment e.g. under-corrected refractive errors and/or cataracts. It may not be a surprise to learn that many older patients put their poor vision down to “just my age” and are unaware that these are correctable visual impairments.
As a minimum, part of our falls prevention strategy should include routine advice for patients to have their eyes tested every 2 years or as advised by their optician. The multifactorial falls asessment should include an assessment of visual acuity of both eyes, which at the very least will identify reduced vision as a start!