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Aims: To measure the prevalence of visual impairment in a large representative sample of people aged 75 years and over participating in the MRC trial of assessment and management of older people in the community. Methods: 53 practices in the MRC general practice research framework. Data were obtained from 14 600 participants aged 75 years and older. Prevalence of visual impairment overall (binocular visual acuity <6/18) which was categorised separately into low vision (binocular visual acuity <6/18-3/60) or blindness (binocular visual acuity of <3/60). The prevalence of binocular acuity <6/12 was presented for comparison with other studies. Visual acuity was measured using Glasgow acuity charts; glasses, if worn, were not removed. Results: Visual acuity was available for 14 600 people out of 21 241 invited (69%). Among people with visual acuity data, 12.4% overall (1803) were visually impaired (95% confidence intervals 10.8% to 13.9%); 1501 (10.3%) were categorised as having low vision (8.7% to 11.8%), and 302 (2.1%) were blind (1.8% to 2.4%). At ages 75-79, 6.2% of the cohort were visually impaired (5.1% to 7.3%) with 36.9% at age 90+ (32.5% to 41.3%). At ages 75-79, 0.6% (0.4% to 0.8%) of the study population were blind, with 6.9% (4.8% to 9.0%) at age 90+. In multivariate regression, controlling for age, women had significant excess risk of visual impairment (odds ratio 1.43, 95% confidence interval 1.29 to 1.58). Overall, 19.9% of study participants had a binocular acuity of less than 6/12 (17.8% to 22.0%). Conclusion:The results from this large study show that visual impairment is common in the older population and that this risk increases rapidly with advancing age, especially for women. A relatively conservative measure of visual impairment was used. If visual impairment had been defined as visual acuity of <6/12 (American definition of visual impairment), the age specific prevalence estimates would have increased by 60%. V isual impairment and blindness are common in older people. There have been a number of population based studies conducted in Britain and in other European populations in North America and Australia.1-12 Several of these studies were small and many investigated people aged 40 years and above. There is little information on the prevalence of visual impairment and blindness in people aged 75 years or more with particularly limited data for people aged 90 years and older.As part of the assessment of the health of older people in the MRC trial of the assessment and management of older people in the community, a visual acuity screening test was conducted by trained nurses in a representative group of almost 15 000 people aged 75 years and older recruited from general practices in Britain (England, Scotland, and Wales). METHODSThe MRC trial of the assessment and management of older people in the community This is a large cluster randomised trial taking place in 106 general practices from the Medical Research Council general practice research framework. The practices in the study were selected...

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Summary. Retinal blood flow was studied in 9 normal volunteers and 36 diabetic patients. The method used was based on the measurement of the mean transit time of flourescein in the superior temporal quandrant of the retina and on estimation of the vascular volume by measuring vessels diameters. The results showed that patients with mild or no retinopathy had significantly increased volume flow compared with normals, those with moderate retinopathy had a slight but not significant increase and those with severe retinopathy had blood flow similar to that found in normals. The mean transit time was reduced significantly in those with mild or no retinopathy, but was similar to normals in those with moderate and severe retinopathy. Following succesful pituitary ablation and photocoagulation retinal blood flow was reduced compared with pre-treatment studies.