Causes of visual impairment in people aged 75 years and older in Britain: an add-on study to the MRC Trial of Assessment and Management of Older People in the Community
- 1Department of Epidemiology and International Eye Health, Institute of Ophthalmology, London, UK
- 2Centre for Ageing and Public Health, London School of Hygiene and Tropical Medicine, London, UK
- Correspondence to: Ms Jennifer Evans Department of Epidemiology and International Eye Health, Institute of Ophthalmology, London, UK;
- Accepted 28 May 2003
Background: Visual impairment and blindness are common in older people in Britain. It is important to know the causes of visual impairment to develop health service and research priorities. The authors aimed to identify the causes of visual impairment in people aged 75 years and older in Britain.
Methods: In the MRC Trial of the Assessment and Management of Older People in the Community, trial nurses tested visual acuity in everyone aged 75 years and older in 53 general practices. For all visually impaired patients in 49 of the 53 medical practices, data regarding the cause of vision loss were extracted from the general practice medical notes. Additional follow up questionnaires were also sent to the hospital ophthalmologist to confirm the cause of vision loss. Visual impairment was defined as a binocular acuity of less than 6/18.
Results: There were 1742 (12.5%) people visually impaired in the 49 participating practices. Of these, 450 (26%) achieved a pinhole visual acuity in either eye of 6/18 or better. In these people, the principal reason for visual loss was considered to be refractive error. The cause of visual loss was available for 976 (76%) of the remaining 1292 visually impaired people identified. The main cause of visual loss was age related macular degeneration (AMD); 52.9% (95% confidence interval 49.2 to 56.5) of people had AMD as a main or contributory cause. This was followed by cataract (35.9%), glaucoma (11.6%), myopic degeneration (4.2%), and diabetic eye disease (3.4%).
Conclusions: A substantial proportion of visual impairment in our sample of older people in Britain can be attributed to remediable causes—refractive error and cataract. There is considerable potential for visual rehabilitation in this age group. For the large proportion with macular degeneration, low vision services will be important.
Funding: The MRC Trial of the Assessment and Management of Older People in the Community was funded by the UK Medical Research Council, the Department of Health, and the Scottish Office. Collection of data on causes of visual impairment was funded by the Gift of Thomas Pocklington.
Conflict of interest: None.