ABSTRACT
BACKGROUND/AIMS: Retinal screening programmes in England and Scotland have similar photographic grading schemes for background (non-proliferative) and proliferative diabetic retinopathy, but diverge over maculopathy. We looked for the most cost-effective method of identifying diabetic macular oedema from retinal photographs including the role of automated grading and optical coherence tomography, a technology that directly visualises oedema. METHODS: Patients from seven UK centres were recruited. The following features in at least one eye were required for enrolment: microaneurysms/dot haemorrhages or blot haemorrhages within one disc diameter, or exudates within one or two disc diameters of the centre of the macula. Subjects had optical coherence tomography and digital photography. Manual and automated grading schemes were evaluated. Costs and QALYs were modelled using microsimulation techniques. RESULTS: 3540 patients were recruited, 3170 were analysed. For diabetic macular oedema, England's scheme had a sensitivity of 72.6% and specificity of 66.8%; Scotland's had a sensitivity of 59.5% and specificity of 79.0%. When applying a ceiling ratio of £30,000 per quality adjusted life years (QALY) gained, Scotland's scheme was preferred. Assuming automated grading could be implemented without increasing grading costs, automation produced a greater number of QALYS for a lower cost than England's scheme, but was not cost effective, at the study's operating point, compared with Scotland's. The addition of optical coherence tomography, to each scheme, resulted in cost savings without reducing health benefits. CONCLUSIONS: Retinal screening programmes in the UK should reconsider the screening pathway to make best use of existing and new technologies.
Subject(s)
Diabetic Retinopathy/diagnosis , Macular Edema/diagnosis , Mass Screening/economics , Photography/economics , Adult , Aged , Automation , Cost-Benefit Analysis , Diabetic Retinopathy/economics , Female , Humans , Macular Edema/economics , Male , Mass Screening/methods , Middle Aged , Photography/methods , Prospective Studies , Quality Improvement/economics , Quality-Adjusted Life Years , Sensitivity and Specificity , Tomography, Optical Coherence/economics , Tomography, Optical Coherence/methods , United KingdomABSTRACT
OBJECTIVE: Cerebral microvascular disease associated with type 2 diabetes may exacerbate the effects of aging on cognitive function. A considerable homology exists between the retinal and cerebral microcirculations; a hypothesized association between diabetic retinopathy (DR) and cognitive decline was examined in older people with type 2 diabetes. RESEARCH DESIGN AND METHODS: In the population-based Edinburgh Type 2 Diabetes Study, 1,046 men and women aged 60-75 years with type 2 diabetes underwent standard seven-field binocular digital retinal photography and a battery of seven cognitive function tests. A general cognitive ability score (g) was generated by principal components analysis. The Mill-Hill Vocabulary Scale was used to estimate premorbid cognitive ability. DR was graded using a modification of the Early Treatment of Diabetic Retinopathy Scale. RESULTS: After age and sex adjustment, a significant relationship was observed with increasing severity of DR (none, mild, and moderate to severe) for most cognitive measures. Participants with moderate-to-severe retinopathy had the worst g and the worst performances on the individual tests. There was a significant interaction between sex and retinopathy for g. In male subjects, the associations of retinopathy with g (and with tests of verbal fluency, mental flexibility, and processing speed but not memory and nonverbal reasoning) persisted (P < 0.05) when further adjusted for vocabulary (to estimate lifetime cognitive decline), depression, sociodemographic characteristics, cardiovascular risk factors, and macrovascular disease. CONCLUSIONS: DR was independently associated with estimated lifetime cognitive decline in older men with type 2 diabetes, supporting the hypothesis that cerebral microvascular disease may contribute to their observed accelerated age-related cognitive decline. A sex interaction with stronger findings in men requires further confirmation.
Subject(s)
Cognition Disorders/etiology , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/psychology , Diabetic Retinopathy/etiology , Aged , Cerebrovascular Circulation , Cognition/physiology , Cognition Disorders/physiopathology , Cohort Studies , Cross-Sectional Studies , Diabetes Mellitus, Type 2/drug therapy , Diabetic Angiopathies/epidemiology , Educational Status , Female , Health Surveys , Humans , Hypoglycemic Agents/therapeutic use , Insulin/therapeutic use , Male , Memory , Middle Aged , Scotland , Sex Characteristics , Vision, Binocular , Visual AcuityABSTRACT
AIM: Diabetic patients are at significant risk of developing corneal lesions such as superficial punctate keratitis, recurrent corneal erosions, persistent epithelial defects, and microbial keratitis. The aim of this study was to investigate whether diabetes mellitus is correlated with both reduced corneal sensation and reduced tear production. METHODS: In 25 type II diabetic patients with a history of retinopathy only and in 25 nondiabetic control subjects (age and sex matched), we performed noncontact corneal aesthesiometry and assessed basal tear production using Schirmer's test with topical anesthesia. The noncontact corneal aesthesiometer (NCCA) is a new noninvasive device for quantifying threshold corneal sensitivity. RESULTS: The diabetic patients demonstrated a significantly reduced Schirmer's test result (P<.001) and significantly reduced corneal sensitivity (P<.01). CONCLUSION: Our study supports previous reports of reduced basal tear production, lending more support to the theory of a peripheral neuropathy affecting lacrimal gland function in diabetes. We also confirmed reduced threshold corneal sensitivity in diabetic patients using the NCCA.
