Screening for diabetic retinopathy: a survey of health authorities during a period of transition.

Abstract

To the Editor: Diabetic retinopathy is the leading cause of visual loss in working age adults in the United Kingdom (Evans et al. 1996) and yet, for the vast majority of patients with proliferative retinopathy, early laser treatment will stop the loss of vision, and treatment has also been shown to be beneficial for many patients with maculopathy (The Diabetic Retinopathy Research Group 1978; Early Treatment Diabetic Retinopathy Study Research Group 1991). Unfortunately sight‐threatening retinopathy is asymptomatic in its early stages when it is most amenable to treatment and it is only detectable by careful examination of the fundus. This combination of features makes diabetic retinopathy an ideal candidate for screening (Wilson & Jungner 1968) and several economic analysis have established its benefits (Foulds et al. 1983; Javitt et al. 1989; Rohan et al. 1989; Javitt et al. 1994). Guidelines for the screening of diabetic retinopathy recommend checks at least once per year, although it is less clear what method of testing should be used or who should carry out the screen (American Academy of Ophthalmology Quality of Care Committee 1993; Retinopathy Working Party 1991). In Britain many local schemes have been developed through the individual initiatives of ophthalmologists, diabetologists, optometrists or general practitioners. Some schemes use ophthalmoscopy to examine the fundus while others rely on photography. Research suggests that both ophthalmoscopy by an experienced user and photography through a dilated pupil give acceptable sensitivity, that a non‐mydriatic camera is less sensitive and that in the hands of a less experienced screener, such as a general practitioner without special training, the quality of ophthalmoscopy will be noticeably worse (Taylor et al. 1990; Buxton et al. 1991; Patel et al. 1992). The World Health Organisation and the International Diabetes Federation were concerned at the failure of health services to prevent blindness from diabetic retinopathy and other complications of diabetes and together produced the St Vincent Declaration, one aim of which was to reduce new cases of blindness due to diabetes by a third in five years (World Health Organisation & International Diabetic Federation Europe. 1990). In Britain the government's ‘Health of the Nation’ document acknowledged the aims of the St Vincent Declaration but pointed out the lack of good outcome measures needed to monitor whether the stated aims are being met (Department of Health 1991). It suggests an eventual aim of introducing diabetic retinopathy screening for all those ‘at high risk’. The UK Task Force was formed in 1993 with input from the Department of Health and the British Diabetic Association. The Task Force aimed to see the implementation of the St Vincent Declaration in the UK by the year 2000 (St Vincent Task Force for Diabetes 1994). The St Vincent Declaration has encouraged widespread efforts to improve the provision of screening for diabetic retinopathy. Against this background of change, an intercollegiate collaborative project is underway, auditing the coverage achieved by existing screening services in Britain. As a first stage in that work, Directors of Public Health in every Health Authority in England and Wales were contacted to find out whether they had a policy on screening for diabetic retinopathy and whether they were purchasing screening services. The results of that survey are presented here.