[show abstract][hide abstract] ABSTRACT: To evaluate the relationship between best corrected visual acuity (BCVA), age, type of diabetes, sight-threatening diabetic retinopathy (STDR) and ocular co-morbidity.
1549 randomly selected people with diabetes mellitus (DM) from a countywide digital photographic screening programme had standardised logarithm of minimum angle of resolution (logMAR) BCVA measurement, followed by slit-lamp biomicroscopy examination by an experienced ophthalmologist.
Subnormal vision (logMAR > or =0.3, Snellen < or =6/12) and blindness (logMAR >1.3, Snellen <3/60) in the better-seeing eye were found in 9.0% and 0.45%. The sensitivity, specificity and positive and negative predictive values of using subnormal vision to screen for STDR in an individual eye were 33.4%, 85.9%, 18.6% and 93.0%, respectively. Important contributory causes of moderate visual loss (logMAR 0.50 to 0.98, Snellen 6/18 or worse but better than 6/60) and of Acuity Blindness (logMAR > or =1.0, Snellen 6/60 or worse) in an individual eye were lenticular opacity (including capsular opacification) 49%, macular degeneration (including myopic degeneration) 29%, diabetic maculopathy 15%, other media causes (including corneal opacity) 13% and amblyopia 10%.
The majority of visual loss in a population with diabetes is due to causes other than diabetic retinopathy. BCVA alone is not a reliable criterion in predicting STDR.
The British journal of ophthalmology 06/2008; 92(6):775-8. · 2.92 Impact Factor
[show abstract][hide abstract] ABSTRACT: OBJECTIVES: The main objective of the national screening programme is to reduce the risk of sight loss among people with diabetes due to diabetic retinopathy (DR). METHODS: Offering two-field mydriatic digital photographic screening to all people with diabetes in England over the age of 12 years. STAGE OF DEVELOPMENT: The programme is in its infancy, receiving the first year's annual reports from approximately 96 screening programmes, each of which have developed to offer screening to a minimum number of 12,000 people with diabetes, which would cover a population of 350,000 people with 3.4% diabetes prevalence. The national programme has commenced the External quality assurance (QA) programme in order to achieve and sustain the highest possible standards. POTENTIAL BENEFITS: England has a population of two million people with diabetes over the age of 12 and it is believed that there is a prevalence of blindness of 4200 and an annual incidence of blindness of 1280 people with diabetes. This programme has the potential to reduce the prevalence of blindness in England from 4200 people to 1000 people and a conservative estimate of reducing the annual incidence of DR blindness by one-third would save 427 people per annum from blindness. These figures are based on the UK certification of blindness but if World Health Organization (WHO) definitions are used the prevalence, incidence and potential reductions in blindness are much greater.
Journal of Medical Screening 02/2008; 15(1):1-4. · 2.35 Impact Factor
[show abstract][hide abstract] ABSTRACT: To investigate socioeconomic variations in diabetes prevalence, uptake of screening for diabetic retinopathy, and prevalence of diabetic retinopathy.
The County of Gloucestershire formed the setting of the study. A cross-sectional study of people with diabetes was done on a countywide retinopathy-screening database. Diabetes prevalence with odds ratios, uptake of screening, prevalence of any retinopathy and prevalence of sight-threatening retinopathy at screening were compared for different area deprivation quintiles. Logistic regression was used to adjust for confounding.
With each increasing quintile of deprivation, diabetes prevalence increased (odds ratio 0.84), the probability of having been screened for diabetic retinopathy decreased (odds ratio 1.11), and the prevalence of sight-threatening diabetic retinopathy among screened patients increased (odds ratio of 0.98), while the prevalence of non-sight-threatening diabetic retinopathy remained unchanged with each increasing quintile of deprivation.
Sight-threatening diabetic retinopathy was associated with socioeconomic deprivation, but non-sight-threatening diabetic retinopathy was not. Uptake of screening was inversely related to socioeconomic deprivation.
Journal of Medical Screening 02/2008; 15(3):118-21. · 2.35 Impact Factor
[show abstract][hide abstract] ABSTRACT: To explore the patient experience of symptoms of eye disease related to diabetes and its treatment, including increase of symptoms over time and their relation to severity of the condition and the effect of multiple treatments and symptoms on quality of life.
A qualitative interview study was implemented at four eye clinics in the UK. This study design was intended to yield 240 interviews in patients having their first laser treatment or first follow-up and in multi-treatment patients with a clinically documented loss of visual function in at least one eye (VA </= 6/12). The intention was to have an approximately equal number of patients with proliferative diabetic retinopathy (PDR) or macular oedema (MO).
A total of 227 interviews were completed (54% PDR and 46% MO). The most frequently reported symptom prior to initial treatment was blurred vision (55%). First-time-treatment patients reported fewer symptoms than the multi-treatment patients. After a pronounced reduction of quality-of-life impacts after the first laser treatment, results all demonstrate an increasing impact as patients move from first treatment to multiple treatments. The main responses regarding satisfaction with laser treatment were that, although patient expectations were basically met, the treatment had less of an impact than they hoped for, and they would have the treatment again if needed.
The current study provides a qualitative exploration of visual symptoms, levels of self-reported visual impairment, and general description of the areas of impact or restriction that patients experienced due to their eye disease, both pre- and post-laser treatment.
Diabetic Medicine 02/2006; 23(1):60-6. · 3.24 Impact Factor
[show abstract][hide abstract] ABSTRACT: To determine how the workload of an ophthalmology department changed following the introduction of an organised retinal screening programme.
Information was collected from the hospital medical record of people with diabetes attending eye clinics over 4 years. The first year was before screening, the next 2 years the first round, and the fourth year the second round.
The total number of people with diabetes referred each year over the 4 year period was 853, 954, 974, 1051 consecutively. The number of people with diabetes in the county rose by 1400 per annum. The total number of referrals for an opinion about diabetic retinopathy was 227, 333, 363, 368, for cataract was 64, 57, 77, 93, and for glaucoma was 57, 62, 61, 68. The total number of patients referred for laser treatment over the 4 years was 77, 124, 111, and 63
This study suggests that the workload in the eye clinic increases in the first round of screening but in subsequent rounds it does not fall below the pre-screening level, except for laser treatment. This may be partly because of increasing numbers of people with diabetes. With the introduction of a national screening programme, this has significant workload implications for the National Health Service.
British Journal of Ophthalmology 09/2005; 89(8):971-5. · 2.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: We describe a pilot study of measurement of quality assurance targets for diabetic retinopathy screening and performance comparison between 10 existing services, in preparation for the roll-out of the national programme.
In 1999 the UK National Screening Committee approved proposals for a national diabetic retinopathy risk reduction programme, including recommendations for quality assurance, but implementation was held pending publication of the National Service Framework for Diabetes. Existing services requested the authors to perform a pilot study of a QA scheme, indicating willingness to contribute data for comparison.
Objectives and quality standards were developed, following consultation with diabetologists, ophthalmologists and retinal screeners. Services submitted 2001/2 performance data, in response to a questionnaire, for anonymization, central analysis and comparison.
The 17 quality standards encompass all aspects of the programme from identification of patients to timeliness of treatment. Ten programmes took part, submitting all the data available. All returns were incomplete, but especially so from the optometry-based schemes. Eight or more services demonstrated they could reach the minimum level in only five of the 17 standards. Thirty per cent could not provide coverage data. All were running behind. Reasons for difficulties in obtaining data and/or failing to achieve standards included severe under-funding and little previous experience of QA. Information systems were limited and incompatible between diabetes and eye units, and there was a lack of co-ordinated management of the whole programme.
Quality assurance is time-consuming, expensive and inadequately resourced. The pilot study identified priorities for local action. National programme implementation must involve integral quality assurance mechanisms from the outset.
Diabetic Medicine 11/2004; 21(10):1066-74. · 3.24 Impact Factor
[show abstract][hide abstract] ABSTRACT: A National Screening Programme for diabetic eye disease in the UK is in development. We propose a grading and early disease management protocol to detect sight-threatening diabetic retinopathy and any retinopathy, which will allow precise quality assurance at all steps while minimizing false-positive referral to the hospital eye service.
Expert panel structured discussions between 2000 and 2002 with review of existing evidence and grading classifications. PROPOSALS: Principles of the protocol include: separate grading of retinopathy and maculopathy, minimum number of steps, compatible with central monitoring, expandable for established more complex systems and for research, no lesion counting, no 'questionable' lesions, attempt to detect focal exudative, diffuse and ischaemic maculopathy and fast track referral from primary or secondary graders. Sight-threatening diabetic retinopathy is defined as: preproliferative retinopathy or worse, sight-threatening maculopathy and/or the presence of photocoagulation. In the centrally reported minimum data set retinopathy is graded into four levels: none (R0), background (R1), preproliferative (R2), proliferative (R3). Maculopathy and photocoagulation are graded as absent (M0, P0) or present (M1, P1).
The protocol developed by the Diabetic Retinopathy Grading and Disease Management Working Party represents a new consensus upon which national guidelines can be based leading to the introduction of quality-assured screening for people with diabetes.
Diabetic Medicine 01/2004; 20(12):965-71. · 3.24 Impact Factor
[show abstract][hide abstract] ABSTRACT: To compare two reference standards when evaluating a method of screening for referable diabetic retinopathy.
Clinics at Oxford and Norwich Hospitals were used in a two centre prospective study of 239 people with diabetes receiving an ophthalmologist's examination using slit lamp biomicroscopy, seven field 35 mm stereophotography and two field mydriatic digital photography. Patients were selected from those attending clinics when the ophthalmologist and ophthalmic photographer were able to attend. The main outcome measures were the detection of referable diabetic retinopathy as defined by the Gloucestershire adaptation of the European Working Party guidelines.
In comparison with seven field stereophotography, the ophthalmologist's examination gave a sensitivity of 87.4% (confidence interval 83.5 to 91.5), a specificity of 94.9% (91.5 to 98.3), and a kappa statistic of 0.80. Two field mydriatic digital photography gave a sensitivity of 80.2% (75.2 to 85.2), specificity of 96.2% (93.2 to 99.2), and a kappa statistic of 0.73. In comparison with the ophthalmologist's examination, two field mydriatic digital photography gave a sensitivity of 82.8% (78.0 to 87.6), specificity of 92.9% (89.6 to 96.2), and a kappa statistic of 0.76. Seven field stereo gave a sensitivity of 96.4% (94.0 to 98.8), a specificity of 82.9% (77.4 to 88.4), and a kappa statistic of 0.80. 15.3% of seven field sets, 1.5% of the two field digital photographs, and none of the ophthalmologist's examinations were ungradeable.
An ophthalmologist's examination compares favourably with seven field stereophotography, and two field digital photography performs well against both reference standards.
British Journal of Ophthalmology 11/2003; 87(10):1258-63. · 2.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: To evaluate the introduction of a community-based non-mydriatic and mydriatic digital photographic screening programme by measuring the sensitivity and specificity compared with a reference standard and assessing the added value of technician direct ophthalmoscopy.
Study patients had one-field, non-mydriatic, 45 degrees digital imaging photography prior to mydriatic two-field digital imaging photography followed by technician ophthalmoscopy. Of these patients, 1549 were then examined by an experienced ophthalmologist using slit lamp biomicroscopy as a reference standard. The setting was general practices in Gloucestershire. Patients were selected by randomizing groups of patients (from within individual general practices) and 3611 patients were included in the study. Patients for reference standard examination were recruited from groups of patients on days when the ophthalmologist was able to attend. The main outcome measure was detection of referable diabetic retinopathy (DR) as defined by the Gloucestershire adaptation of the European Working Party guidelines.
For mydriatic digital photography, the sensitivity was 87.8%, specificity was 86.1% and technical failure rate was 3.7%. Technician ophthalmoscopy did not alter these figures. For non-mydriatic photography, the sensitivity was 86.0%, specificity was 76.7% and technical failure rate was 19.7%.
Two-field mydriatic digital photography is an effective method of screening for referable diabetic retinopathy. Non-mydriatic digital photography has an unacceptable technical failure rate and low specificity.
Diabetic Medicine 07/2003; 20(6):467-74. · 3.24 Impact Factor