How can an eye test help someone with dementia?

Post date: 
Friday, 12 May 2017
Michael Bowen

NB Online editor, Hannah Adams, spoke to Michael Bowen, Director of Research at The College of Optometrists and Chief Investigator of the PrOVIDe report, to find out why people with dementia in care homes are more susceptible to sight loss and how optometrists should approach eye tests.

In the UK 850,000 people have dementia; 250,000 of which also live with sight loss. The risk of developing dementia or sight loss (or both) increases with age. As the UK’s population continues to live longer, there’s a danger that more and more people with dementia could have a visual impairment without their families and carers realising. 
Until now, research about dementia and sight loss has been 20-30 years out of date and data hasn’t focused on the UK population. Today, research from the two-year PrOVIDe study offers an up to date view of the prevalence of both conditions and recommendations for a future UK Dementia Eye Care Pathway.
The report’s main finding concludes:
  • there is a high prevalence of all types of visual impairment in older people with dementia, which is disproportionally higher in people with dementia living in care homes
  • almost 50 per cent of people presenting visual impairment could have their sight loss corrected with the right prescription glasses, and more with cataract surgery
Who was interviewed as part of the PrOVIDe study?
“We carried out eye tests with 708 people with dementia aged 60-89 to determine the prevalence of their visual impairment. We recruited people whose dementia ranged in severity, from mild to severe - the study also included participants who were not able to consent to participate due to the degree of cognitive impairment, so there was a good range within the study. 
Two-thirds of people lived in their own home and just over a third lived in residential care. Within that group, we stratified with age groups and by gender to closely match the dementia population of the UK based on the Alzheimer’s Society’s profiling
We then conducted in-depth interviews with some of those people. To get a full picture, we also held focus groups and interviews with family carers, professional care workers and eye health professionals.” 
What questions did you ask in the interviews?
“Our researchers wanted to know about people’s experience of eye care. They asked questions like: ‘When did you last see an optometrist?’, ‘Do you see the same person each time you have an eye test?’, ‘How easy is it to get to the eye test?’, and ‘What kind of visual tasks do you like doing?’”
How did you carry out the eye tests?
“The optometrists involved in gathering data for the project were from The Outside Clinic, a company which carry out eye exams in people’s homes. They had tremendous experience of dealing with people with complex needs and good training with people who have dementia. The average time spent on each examination was an hour. Of course some were shorter and some much longer.
We offered all people the choice of having the test done at home or in a practice setting. As it happened, everyone wanted to have the test at home and interestingly, almost all the people didn’t know the domiciliary service existed.

At the beginning of the project, we had made the conservative estimate that about half of the people wouldn’t complete the majority of the key elements of a sight test. But in fact, 80 per cent of participants could do the crucial elements of the sight test and when patients were prescribed the right glasses, the rate of vision impairments reduced by 50 per cent.”

How did people see the eye examination in the context of having dementia?
"The qualitative data from PrOVIDe suggests that in many cases, once a person has a dementia diagnosis, it can feel like a powerful and overwhelming focus is given to the dementia and other things are excluded or their relative importance diminishes. 

Family and professional carers expressed the view that loss of vision might be difficult to address because of the dementia, and even if it was possible to do something to improve vision, there were questions about the benefit to someone living with dementia, which was perceived as being the primary issue. Some questioned why should they bother trying to treat it, how would it help anyway?"

How can optometrists tailor eye exams when dementia is a factor?
“Visual fields testing and subjective refraction were the elements of the sight test that participants were more likely to struggle with.  That’s not to say optometrists should avoid attempting the visual field elements, but maybe optometrists should leave it till last and be prepared to step back if the person doesn’t have the energy. 
PrOVIDe optometrists found that confrontation fields were generally more effective as a means of collecting some information on this aspect of vision.
Overall, we concluded that more time is needed when carrying out an eye exam on a person with dementia. It could also be a good idea to break the exam up into two sections to help them do as much of the test as possible, but be prepared to stop for a break if they become tired.”
Why are people with dementia at least twice as likely to have vision impairment when in a care home?
“We have to be cautious when trying to answer a question like this. The PrOVIDe research hasn’t given us definitive answers to this but findings show strongly that more research is needed to explore further the reasons why sight loss and dementia are more prevalent in care homes. 
One plausible hypothesis is that if a person has concurrent dementia and sight loss, they are more likely to need to live in a care home. 
There are other factors too. It may have been that people living in care homes were more likely to attend the PrOVIDe eye examination with the wrong glasses - an older pair of their own or someone else’s by mistake. However, there was always a carer present during exams so this should not account for all of the difference between visual impairment between those in their own homes and those living in care homes that we found. 
Also, perhaps a small amount of the difference could be due to the fact that residents might not have had such effective outcomes from previous sight tests. Many optometrists who are conducting sight tests in care homes will not have so much time for each patient as was given in the study. They may be seeing multiple patients in a single visit, which can be more convenient for the care home staff.  

Care homes are very busy places. An example of this from the study was that our researchers found it difficult to gather care home staff together in group focus sessions and even a 30-minute chat felt almost impossible. You can’t underestimate how under-resourced care homes can be. There’s a tremendous demand on staff and they do a fantastic job. What might seem like a 'simple, relatively short sight test' to you or me, can be very disruptive to the schedule and routine of a care home.” 

How confident are optometrists in delivering eye tests to people with dementia?
“There are lots of optometrists out there who are very comfortable delivering eye examinations to people with dementia. But there’s always going to be a spread of competency based on people’s experience. One person who is very competent with dementia patients may not be as confident when seeing a child under five for example, it really comes down to what they’ve had most experience of. 
If an optometrist hasn’t had a great deal of experience of testing a person with dementia, they can worry they’re wasting the patient’s time or their own. 

Some of the optometrists who took part in the PrOVIDe focus groups did not feel enough training and support is available to support them to develop the skills needed to examine people with dementia. We haven’t looked formally at how dementia is covered in the undergraduate curriculum but so far as I am aware there aren't whole modules taught on the subject. Certainly, getting more evidence-based materials is something we’re looking to do from the secondary analysis.” 

Final thoughts
Following on from the PrOVIDe report, pilot research has already been undertaken into whether tests are most effective in assessing vision in people living with dementia. This is being led on by Michael’s team at The College of Optometrists and the Dementia Research Centre at UCL. Funding is needed to take it further.
The report has also informed a proposal for a UK Dementia Eye Care Pathway. 
(The PrOVIDe research was funded by the National Institute for Health Research (NIHR) Health Services and Delivery Research Programme (HS&DR ) (project number 11/2000/13). The views and opinions expressed within the report are those of the authors and do not necessarily reflect those of the HS&DR, NIHR, NHS or the Department of Health.)
Further information
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