incident VI would be more useful. Despite these limitations, data on VI registration rates may be useful as estimates of incidence of VI and to establish a baseline for DR screening programmes. Conclusions From our study it would appear that registration of severe VI secondary to DR is uncommon and does not appear to be the main cause of VI registration in the working age group in this population of Cambridgeshire. The severe VI registration rate due to DR lies within the 1990–1991 national standard. The VI registration rate exceeds 1990–1991 national stan- dard but lies within 1999–2000 national ﬁgures. These rates form a baseline for the region, to which future rates can be compared. We are unlikely to be able to achieve a lower rate of severe VI registration from DR. Improvement in VI due to DR may depend on improving other aspects of diabetic care, such as control of blood glucose and blood pressure, particularly before retinopathy occurs, and timely referral of patients with sight-threatening retinopathy. Acknowledgments We thank the visual impairment liaison coordinator Lynette Gayfer, the secretarial staff and receptionists of Addenbrookes and Hinchingbrooke Hospitals, the primary care trusts within Cambridgeshire, and Jan Suart-Menteath of Cambridgeshire City Council. Disclosure The authors report no conﬂicts of interest in this work. No funding was received for this study. References 1. UK National Screening Committee. Essential elements in developing a diabetic retinopathy screening programme, Workbook 3. Nov. 2004. 2. Garvican L, Scanlon P. Quality Assurance for the National Screening Programme for Sight-threatening Diabetic Retinopathy: Development of a Set of Key Quality Assurance Standards. Sept. 2003. Available from: http://www.nscretinopathy.org.uk/resources/FinalQAStdsSept03.doc. Registration of visual impairment due to diabetic retinopathy 3. Evans JR. Causes of blindness and partial sight in England and Wales 1990–91, Studies on Medical and Population Subjects Reports No. 57 HMSO: London, 1995. 4. National Screening Programme for Diabetic Retinopathy. Template for Annual Report – Release 3. July 20, 2005. 5. Bunce C, Wormald R. Leading causes of certiﬁcation for blindness and partial sight in England and Wales. BMC Public Health. 2006;6:58. 6. Evans JR, Rooney C, Ashwood F, et al. Blindness and partial sight in England and Wales: April 1990–March 1991. Health Trends. 1996;28:5–12. 7. Cormack TG, Grant B, Macdonald MJ, et al. Incidence of blindness due to diabetic eye disease in Fife 1990–9. Br J Ophthalmol. 2001;85:354–6. 8. Kumar N, Goyder E, McKibbin M. The incidence of visual impairment due to diabetic retinopathy in Leeds. Eye. 2006;20:455–9. 9. National Diabetes Audit. Key ﬁndings about the quality of care for people with diabetes in England. Report for the audit period 2003/04. 10. Mather HM, Keen H. The Southall Diabetes Survey: prevalence of known diabetes in Asians and Europeans. Br Med J (Clin Res Ed ). 1985;291:1081–4. 11. Cowie CC, Rust KF, Byrd-Holt DD, et al. Prevalence of diabetes and impaired fasting glucose in adults in the U.S. Population: National Health and Nutrition Examination survey 1999–2002. Diabetes Care. 2006;29:1263–8. 12. Bamashmus MA, Matlhaga B, Dutton GN. Causes of blindness and visual impairment in the West of Scotland. Eye. 2004;18:257–61. 13. Hayward LM, Burden ML, Burden AC, et al. What is the prevalence of visual impairment in the general and diabetic populations: are there ethnic and gender differences? Diabet Med. 2002;19:27–34. 14. Pardhan S, Gilchrist J, Mahomed I. Impact of age and duration on sight-threatening retinopathy in South Asians and Caucasians attending a diabetic clinic. Eye. 2004;18:233–40. 15. Barry RJ, Murray PI. Unregistered visual impairment: is registration a failing system? Br J Ophthalmol. 2005;89:995–8. 16. Robinson R, Deutsch J, Jones HS, et al. Unrecognised and unregistered visual impairment. Br J Ophthalmol. 1994;78:736–40. 17. Bunce C, Evans J, Fraser S, et al. BD8 certiﬁcation of visually impaired people. Br J Ophthalmol. 1998;82:72–6. 18. Canavan YM, Jackson AJ, Stewart A. Visual impairment in Northern Ireland. Ulster Med J. 1997;66:92–5. 19. Pardhan S, Mahomed I. The clinical characteristics of Asian and Caucasian patients on Bradford’s Low Vision Register. Eye. 2002;16:572–6. Clinical Ophthalmology 2009:3 79