An evaluation of the change in activity and workload arising from diabetic ophthalmology referrals following the introduction of a community based digital retinal photographic screening programme.

AIMS: To determine how the workload of an ophthalmology department changed following the introduction of an organised retinal screening programme. METHODS: 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. RESULTS: 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 CONCLUSION: 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.

The effectiveness of screening for diabetic retinopathy by digital imaging photography and technician ophthalmoscopy.

AIMS: 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. METHODS: 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. RESULTS: 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%. CONCLUSIONS: 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.

Adding retinal photography to screening for diabetic retinopathy: a prospective study in primary care.

OBJECTIVE: To evaluate whether adding retinal photography improved community screening for diabetic retinopathy. SETTING: Mobile screening unit at rural and urban general practices in south west England. SUBJECTS: 1010 diabetic patients from primary care. DESIGN: Prospective study; patients were examined by ophthalmoscopy by general practitioners or opticians without fundal photographs and again with photographs, and assessments were compared to those of an ophthalmologist. MAIN OUTCOME MEASURES: Whether fundal photography improved the sensitivity of detection of retinopathy and referrable diabetic retinopathy, and whether this sensitivity could be improved by including a review of the films by the specialist. RESULTS: Diabetic retinopathy was detected by the ophthalmologist in 205 patients (20.5%) and referrable retinopathy in 49 (4.9%). The sensitivity of the general practitioners and opticians for referrable retinopathy with ophthalmoscopy was 65%, and improved to 84% with retinal photographs. General practitioners' sensitivity in detecting background retinopathy improved with photographs from 22% to 65%; opticians' sensitivity in detecting background retinopathy improved from 43% to 71%. The sensitivity of detecting referrable retinopathy by general practitioners improved from 56% to 80% with photographs; for opticians it improved from 75% to 88%. CONCLUSIONS: Combining modalities of screening by providing photography with specialist review of all films in addition to direct ophthalmoscopy through dilated pupils improves assessment and referral for diabetic retinopathy by general practitioners and opticians. With further training and experience, primary care screeners should be able to achieve a sensitivity that will achieve an effective, acceptable, and economical community based screening programme for this condition.

The scotopic electroretinogram to blue flashes and pattern reversal visual evoked potentials in insulin dependent diabetes.

Pattern reversal visual evoked responses (PR-VEPs), the electroretinogram (ERG) to blue flashes of light in dark adaptation, the steady state ERG to 40 Hz flicker, and alterations in pupil diameter following dark adaptation were studied in 56 juvenile onset diabetics, 34 of whom had no ophthalmoscopic or photographic evidence of diabetic retinopathy (DR-group). The remaining 22 had mild background retinopathy (DR+group). Normal data was obtained from 24 subjects matched for age and sex with diabetics. Skin electrodes were used for all recordings. The scotopic 'b' wave of the ERG was significantly lower in amplitude in the DR- diabetics and it was even more reduced in the DR+group. The PR-VEP was significantly delayed in diabetics but there was no difference between the two groups. The steady state ERG was not significantly different between normals and diabetics. These findings indicate that retinal and more central abnormalities develop early in diabetics. Detection of objective electrophysiological abnormalities may be used to identify persons at risk of developing retinopathy and to monitor the effects of treatment.

Use of thrombolysis for acute myocardial infarction in the presence of diabetic retinopathy in the UK, and associated ocular haemorrhagic complications.

Diabetic retinopathy is still regarded as a relative contraindication to the use of thrombolysis for myocardial infarction because of a perceived risk of intraocular haemorrhage. However, this complication has rarely been reported and the risk may be too small to justify withholding thrombolysis. A questionnaire survey was therefore conducted of members of the Medical and Scientific Section of the British Diabetic Association (BDA), to ascertain the exclusion criteria applied to the use of thrombolysis in patients with diabetic retinopathy in the UK and to identify any related ocular haemorrhagic complications. Replies were received from 128 physicians in 107 centres. Exclusion criteria applied were: any retinopathy 7 (5%), proliferative retinopathy and recent vitreous or pre-retinal haemorrhage 74 (58%), recent vitreous haemorrhage only 25 (20%), thrombolysis given regardless of retinopathy 22 (17%). No cases of intraocular haemorrhage following thrombolysis in diabetic myocardial infarction patients were identified. The risks of this complication appear to be very small and probably do not justify withholding thrombolytic therapy from diabetic patients with most forms of retinopathy, including proliferative.

Detection of diabetic retinopathy in the community using a non-mydriatic camera.

The role of the non-mydriatic fundus camera in detection of diabetic retinopathy was evaluated as part of a comprehensive screening programme for diabetic complications offered to all diabetic patients in a rural town. Retinopathy was demonstrated in 124/358 (35%) of patients screened. Forty-eight patients (13%) were judged to have sight-threatening retinopathy, of whom 29 patients (8% of the total) were not already under the care of an ophthalmologist. However, in only 66% of patients were photographs of both eyes of adequate quality to assess for retinopathy. The percentage of poor quality photographs increased with age in those aged greater than 50 years. It is concluded that the non-mydriatic camera can increase the detection of sight-threatening retinopathy in the community. Although this method of screening is not perfect, because of the number of poor quality photographs, it may be as good as or better than existing screening practices in unselected diabetic populations.

Investigation of a sub-unit vaccine using an animal model of herpes simplex keratitis.

A rabbit and a mouse model of herpes simplex eye disease have been used to evaluate a sub-unit herpes simplex vaccine. Various immunization schedules were investigated. The vaccine was found to stimulate humoral and cellular immune responses and to offer protection against corneal infection with liver herpes simplex virus.

Auditory discrimination as a predictor of reading for bilingual Mexican-American migrant children.

The performance of 61 bilingual Mexican-American migrant children, ages 8 to 14 yr., was compared for Spanish and English formats of the Wepman Auditory Discrimination Test. The two formats correlated significantly with each other and both were predictive of reading recognition as measured by the Peabody Individual Achievement Test. The data suggest that auditory discrimination as measured by the popular Wepman test may not be a pure perceptual skill but may be language bound. Consequently auditory discrimination as a pure perceptual skill may not be accurately assessed in bilingual or monolingual Spanish-speaking children if the Wepman test is used in its published format. A Spanish-based alternative is suggested for assessing auditory discrimination for uses other than reading prediction.