Dementia patients more at risk of sight loss than general population
Thursday, 27 April 2017
Nearly three-quarters of visual impairment in those with dementia addressed through glasses or cataract operation.
Research led by The College of Optometrists found that prevalence of visual impairment (VI) in those with dementia is generally higher than for the overall population, highlighting the importance of sight tests in this group of people. The College’s research also found that almost 50 per cent of those living with dementia and VI were no longer classified as visually impaired when wearing their up-to-date glasses prescription and that VI was approximately 2-2.5 times more common for those people with dementia living in care homes than for those living at home.
The research, entitled the Prevalence of Visual Impairment in People with Dementia (PrOVIDe), was led by the College of Optometrists in collaboration with City, University of London, University of Birmingham, Thomas Pocklington Trust, Alzheimer’s Society, University of Newcastle, Trinity College Dublin and University College London and was funded and published by the National Institute for Health Research. The project also benefitted from in-kind support from The Outside Clinic.
The study aimed to measure the prevalence of a range of vision problems in people with dementia aged 60-89 years to determine the extent to which their vision conditions are undetected or inappropriately managed. The study’s key findings were:
32.5 per cent of people with dementia had visual acuity (VA) worse than 6/12 (the legal standard for driving) and 16.3 per cent had VA worse than 6/18 (a commonly used international standard for defining when someone is 'visually impaired'). These figures are generally higher than in comparable data from prevalence studies on the general population (after adjustment for age and gender)
Almost 50 per cent of those with VI were no longer classified as visually impaired when wearing their up-to-date glasses prescription
22 per cent of participants reported not having had a sight test in the previous two years, including 19 participants who had not been tested in the last ten years
VI was approximately 2-2.5 times more common in those living in care homes than for those living in their own homes, even after age and gender had been controlled for
Once refractive error was accounted for: Cataract was the primary cause of VI in those with VA worse than 6/12. Cataract is treatable with surgery in suitable patients. And, Age-related macular degeneration (AMD) was the primary cause of VI in those with VA worse than 6/18
16 per cent of participants could not read standard newspaper-size print with their current glasses, however, almost two-thirds these participants could read this print wearing a prescription given following a dementia-friendly sight test.
Of particular note to practising optometrists, the study highlighted:
The need to allow more time when examining people with dementia. For individuals having an eye examination who are accompanied by a carer or professional care worker, it’s important that the care worker knows the individual and has relevant information to hand. Their input is described by participating optometrists as ‘invaluable’
Optometrists are not always informed that an individual has dementia before their examination takes place. This knowledge is a very significant factor in achieving the best outcome for the individual
Optometrists did not feel enough training and support is provided to examine people with dementia
Carers and care workers were unsure that people with dementia could have a full eye examination if they had difficulty answering questions; however it was possible to conduct key components of the exam with more than 80 per cent of people examined.
Mike Bowen, Director of Research at the College of Optometrists, and chief investigator for the study said; “Risks of both dementia and visual impairment increase with age, so a large proportion of people with dementia may also have visual impairment. We hope that this research will help professionals to understand the importance of vision to those with dementia. This in turn, can help us to provide better care and help improve quality of life for this growing group within the population.
“Optometrists are not always informed when an individual has dementia, which is a very significant factor in achieving the best outcome for the individual. This study gives us some very clear information, such as that a carer’s knowledge of the history of the person with dementia is very valuable to the optometrist. We’ve also learned that some optometrists do not think that they have enough training or support to effectively examine the sight of those with dementia and we will work to provide up-to-date training resources to our members as part of our strategy to implement the report’s findings.
The College has generated a set of resources for members to use in everyday practice, supporting them in offering the best possible eye care to patients with dementia, including peer discussion case studies, a PrOVIDe presentation from researcher, Professor David Edgar,and a DOCET programme about dementia.
James Pickett, Head of Research at Alzheimer’s Society said: “We know all too well how important it is for people affected by dementia to access good quality eye care.
“The study helps to address the vast misconceptions that it is difficult or impossible for people living with dementia to get an eye test. It is not only possible but hugely important. The findings also show that for a large number of people affected by dementia, a simple correction such as getting glasses or surgery can greatly improve their quality of life.
“We need to make sure that both eye professionals and people affected by dementia understand the importance of accessing eye care, and how correcting vision impairments can make a significant difference to the lives of people living with dementia.”
A parliamentary launch for the PrOVIDe research took place on 25 April. It aimed to raise awareness of optometry, the College, and the issues related to vision and dementia. The event was sponsored by MP Debbie Abrahams, who is the Chair of the Dementia All-Party Parliamentary Group.