John D. Ellis

Frequency and predictors of hypoglycaemia in Type 1 and insulin-treated Type 2 diabetes: a population-based study.

Aims  To ascertain the frequency and identify predictors of self‐reported hypoglycaemia in Type 1 and insulin‐treated Type 2 diabetes.

Screening uptake in a well-established diabetic retinopathy screening program: the role of geographical access and deprivation.

OBJECTIVE—To identify criteria that affect uptake of diabetes retinal screening in a community screening program using mobile retinal digital photography units. RESEARCH DESIGN AND METHODS—Data from the regional diabetes population-based retinal screening program and regional ophthalmology laser database were linked to patient postal code (zip code) data. We used distance from retinal screening event, social deprivation scores, and demographic information to identify risk factors for nonattendance at a diabetes retinal screening event. Patients were subdivided into urban (>125,000 population), other urban (3,000–125,000 population), or rural (<3,000 population) depending on where they lived. Data were collected from 2004 to 2006 inclusive and included 15,150 patients and 32,621 eye screening records. RESULTS—The mean ± SD age of patients was 63 ± 15 years, and 54% were male. Mean travel time to retinal screening event varied from 7.1 to 17.0 min. For 12% of missed appointments, patients were more likely to be younger, to have longer diabetes duration, to have poor A1C and blood pressure control, to be smokers, and to live in deprived areas. Poor attendance was not associated with sex or distance to retinal screening event. CONCLUSIONS—Social deprivation is strongly associated with poor attendance at retinal screening events. Time traveled to screening event was not associated with attendance in this study of a mobile retinal screening service, which visited general practitioner surgeries. This data can help inform population-based diabetes retinal screening programs about improving patient uptake.

Diabetic Retinopathy: More Patients, Less Laser: A longitudinal population-based study in Tayside, Scotland

OBJECTIVE—We aim to correlate the incidence of diabetic retinopathy and maculopathy requiring laser treatment with the control of risk factors in the diabetic population of Tayside, Scotland, for the years 2001–2006. RESEARCH DESIGN AND METHODS—Retinal laser treatment, retinal screening, and diabetes care databases were linked for calendar years 2001–2006. Primary end points were the numbers of patients undergoing first or any laser treatment for diabetic retinopathy or maculopathy. Mean A1C and blood pressure and retinal screening rates were followed over the study period. RESULTS—Over 6 years, the number of patients with diabetes in Tayside increased from 9,694 to 15,207 (57% increase). The number of patients receiving laser treatment decreased from 222 to 138 and first laser treatments decreased from 100 (1.03% of diabetic population) to 56 (0.37%). The number of patients with type 2 diabetes treated for maculopathy decreased from 180 in 2001 to 103 in 2006 (43% reduction, P = 0.03). Mean A1C decreased for type 1 and type 2 diabetic populations (P < 0.01) and a reduction in blood pressure was observed in type 2 diabetic patients (P < 0.01). The number of patients attending annual digital photographic retinopathy screening increased from 3,012 to 11,932. CONCLUSIONS—Laser treatment for diabetic maculopathy in type 2 diabetic patients has decreased in Tayside over a six-year period, despite an increased prevalence of diabetes and increased screening effort. We propose that earlier identification of type 2 diabetes and improved risk factor control has reduced the incidence of maculopathy severe enough to require laser treatment.

Prevalence of Diabetic Eye disease in Tayside, Scotland (P‐DETS) Study: methodology

Aims  To describe the use of a validated diabetes register for sampling frame generation and assessment of the representative nature of participants in a fieldwork study of diabetic eye disease.

Glaucoma incidence in an unselected cohort of diabetic patients: is diabetes mellitus a risk factor for glaucoma?

AIMS To evaluate whether diabetes mellitus is a risk factor for the development of primary open angle glaucoma or ocular hypertension (OHT). METHODS A historical cohort study of an unselected population comprising all residents of the Tayside region of Scotland was performed using record linkage techniques followed by case note review. Ascertainment of prevalent diabetes was achieved using the Diabetes Audit and Research in Tayside Study (DARTS) validated regional diabetes register. Glaucoma and treated OHT were defined by encashment of community prescriptions and the statutory surgical procedure coding database. RESULTS The study population comprised 6631 diabetic subjects and 166 144 non-diabetic subjects aged >40 years without glaucoma or OHT at study entry. 65 patients with diabetes and 958 without diabetes were identified as new cases of glaucoma or treated OHT during the 24 month study period, yielding a standardised morbidity ratio of 127 (95% CI, 96-158). Case note review demonstrated non-differential misclassification of prevalent glaucoma and OHT as incident disease (diabetic cohort 20%, non-diabetic cohort 24%; p=0.56) primarily as a result of non-compliance in medically treated disease. Removing misclassified cases and adjusting for age yielded an incidence of primary open angle glaucoma in diabetes of 1.1/1000 patient years (95% CI, 0.89-1. 31) compared to 0.7/1000 patient years (95% CI, 0.54-0.86) in the non-diabetic cohort; RR 1.57 (95% CI, 0.99-2.48). CONCLUSIONS This study failed to confirm an association between diabetes mellitus and primary open angle glaucoma and ocular hypertension. A non-significant increase in diagnosed and treated disease in the diabetic population was observed, but evidence was also found that detection bias contributes to this association.

Review: Overview of diabetic eye disease:

Visual impairment in diabetes is much more common than blindness, and causes major functional disability. Much of this could be avoided by early detection using comprehensive eye screening programmes. These would be most efficiently delivered by digital photography, and automated grading of normal images. Slit lamp examination would provide back-up for patients whose eyes are difficult to examine. It may be possible to extend screening intervals for patients with no baseline retinopathy. There is strong evidence that aggressive glycaemic and blood pressure control prevent development and progression of retinal disease. Laser treatment is less successful in preventing visual loss in maculopathy than in proliferative retinopathy. New drugs such as protein kinase-C inhibitors may become available to treat diabetic retinal disease.