Background:

The prevalence of visual impairment (VI) and dementia increases with age and these conditions may coexist, but few UK data exist on VI among people with dementia.

Objectives:

To measure the prevalence of eye conditions causing VI in people with dementia and to identify/describe reasons for underdetection or inappropriate management.

Design:

Stage 1 – cross-sectional prevalence study. Stage 2 – qualitative research exploring participant, carer and professional perspectives of eye care.

Setting:

Stage 1 – 20 NHS sites in six English regions. Stage 2 – six English regions.

Participants:

Stage 1 – 708 participants with dementia (aged 60–89 years): 389 lived in the community (group 1) and 319 lived in care homes (group 2). Stage 2 – 119 participants.

Interventions:

Stage 1 gathered eye examination data following domiciliary sight tests complying with General Ophthalmic Services requirements and professional guidelines. Cognitive impairment was assessed using the Standardised Mini-Mental State Examination (sMMSE) test, and functional ability and behaviour were assessed using the Bristol Activities of Daily Living Scale and Cambridge Behavioural Inventory – Revised. Stage 2 involved individual interviews (36 people with dementia and 11 care workers); and separate focus groups (34 optometrists; 38 family and professional carers).

Main outcome measures.:

VI defined by visual acuity (VA) worse than 6/12 or worse than 6/18 measured before and after refraction.

Results:

Stage 1 – when participants wore their current spectacles, VI prevalence was 32.5% [95% confidence interval (CI) 28.7% to 36.5%] and 16.3% (95% CI 13.5% to 19.6%) for commonly used criteria for VI of VA worse than 6/12 and 6/18, respectively. Of those with VI, 44% (VA < 6/12) and 47% (VA < 6/18) were correctable with new spectacles. Almost 50% of remaining uncorrectable VI (VA < 6/12) was associated with cataract, and was, therefore, potentially remediable, and one-third was associated with macular degeneration. Uncorrected/undercorrected VI prevalence (VA < 6/12) was significantly higher in participants in care homes (odds ratio 2.19, 95% CI 1.30 to 3.73; p < 0.01) when adjusted for age, sex and sMMSE score. VA could not be measured in 2.6% of group 1 and 34.2% of group 2 participants (p < 0.01). The main eye examination elements (excluding visual fields) could be performed in > 80% of participants. There was no evidence that the management of VI in people with dementia differed from that in older people in general. Exploratory analysis suggested significant deficits in some vision-related aspects of function and behaviour in participants with VI. Stage 2 key messages – carers and care workers underestimated how much can be achieved in an eye examination. People with dementia and carers were unaware of domiciliary sight test availability. Improved communication is needed between optometrists and carers; optometrists should be informed of the person’s dementia. Tailoring eye examinations to individual needs includes allowing extra time. Optometrists wanted training and guidance about dementia. Correcting VI may improve the quality of life of people with dementia but should be weighed against the risks and burdens of undergoing examinations and cataract surgery on an individual basis.

Limitations:

Sampling bias is possible owing to quota-sampling and response bias.

Conclusions:

The prevalence of VI is disproportionately higher in people with dementia living in care homes. Almost 50% of presenting VI is correctable with spectacles, and more with cataract surgery. Areas for future research are the development of an eye-care pathway for people with dementia; assessment of the benefits of early cataract surgery; and research into the feasibility of specialist optometrists for older people.

Funding:

The National Institute for Health Research Health Services and Delivery Research programme.

Article history

The research reported in this issue of the journal was funded by the HS&DR programme or one of its preceding programmes as project number 11/2000/13. The contractual start date was in October 2012. The final report began editorial review in October 2014 and was accepted for publication in December 2015. The authors have been wholly responsible for all data collection, analysis and interpretation, and for writing up their work. The HS&DR editors and production house have tried to ensure the accuracy of the authors’ report and would like to thank the reviewers for their constructive comments on the final report document. However, they do not accept liability for damages or losses arising from material published in this report.

Declared competing interests of authors

Michael Bowen reports financial support from the College of Optometrists, London, during the conduct of the study and outside the submitted work as full-time employee of the College of Optometrists. Dave Edgar reports financial support from City University London during the conduct of the study and outside the submitted work and other support from the College of Optometrists during the conduct of the study and outside the submitted work. Beverley Hancock reports financial support from the College of Optometrists outside the submitted work. Sayeed Haque reports support from the College of Optometrists during the conduct of the study and outside the submitted work, and support from the University of Birmingham during the conduct of the study and outside the submitted work. Sayeed Haque provides statistical advice to the College of Optometrists Small Grants holders under a paid consultancy agreement. Rakhee Shah reports support from The Outside Clinic during the conduct of the study and outside the submitted work. Sarah Buchanan reports support from the Thomas Pocklington Trust during the conduct of the study and outside the submitted work. Steve Iliffe reports grants from the European Commission during the conduct of the study and grants from the Thomas Pocklington Trust outside the submitted work, and other support from University College London, during the conduct of the study and outside the submitted work. James Pickett reports other support from the Alzheimer’s Society outside the submitted work and during the conduct of the study. John-Paul Taylor reports support from the Institute for Neuroscience, Newcastle University, outside the submitted work and during the conduct of the study; and support from the Northumberland, Tyne and Wear NHS Trust, Newcastle upon Tyne, outside the submitted work and during the conduct of the study. Neil O’Leary reports support from Trinity College Dublin outside the submitted work and during the conduct of the study and grant funding from The Irish Longitudinal Study on Ageing (TILDA) during the conduct of the study.