Referral patterns to an ophthalmic outpatient clinic by general practitioners and ophthalmic opticians and the role of these professionals in screening for ocular disease.

Case notes of 1113 consecutive new patients referred to a consultant ophthalmologist at a district general hospital were reviewed to determine the source and efficacy of referrals and the current screening practices of general practitioners and ophthalmic opticians. General practitioners initiated referral in 546 cases (49%) and ophthalmic opticians referral in 439 (39%). Visual loss or visual disturbance was the most important single reason for referral (345 cases; 31%), followed by suspected glaucoma (145 cases; 13%), abnormalities of binocular vision (140; 12.5%), disorders of eyelids or ocular adnexa (127; 11%), and red eye (86; 8%). General practitioners referred many more patients with disorders of the eyelids and adnexa and ophthalmic opticians many more patients with suspected glaucoma. Ophthalmic opticians were far more likely than general practitioners to refer patients with suspected glaucoma correctly. A total of 180 patients (16%) were referred from ocular screening, in 149 cases by ophthalmic opticians and in 10 by general practitioners. Seventy patients had glaucoma or incomplete features of glaucoma, all of them referred by ophthalmic opticians. Of eight diabetic patients referred by ophthalmic opticians, three had asymptomatic disease and in two diabetes was diagnosed as a result of ocular screening. No patient was referred for asymptomatic diabetic retinopathy from screening by general practitioners. Ophthalmic opticians were more likely than general practitioners to diagnose retinopathy requiring photocoagulation. Use of a community based service to screen for glaucoma could save unnecessary consultant outpatient appointments. A similar service could facilitate detection of diabetic retinopathy at a stage when treatment is most effective.     

Comparison of non-mydriatic retinal photography with ophthalmoscopy in 2159 patients: mobile retinal camera study.

OBJECTIVE--To determine whether non-mydriatic Polaroid retinal photography was comparable to ophthalmoscopy with mydriasis in routine clinic screening for early, treatable diabetic retinopathy. DESIGN--Prospective study of ophthalmoscopic findings according to retinal camera screening and ophthalmoscopy and outcome of referral to ophthalmologist. SETTING--Outpatient diabetic clinics of three teaching hospitals and three district general hospitals. PATIENTS--2159 Adults selected randomly from the diabetic clinics, excluding only those registered as blind or those in wheelchairs and unable to enter the screening vehicle. MAIN OUTCOME MEASURES--Numbers of patients and eyes correctly identified by each technique as requiring referral with potentially treatable retinopathy (new vessel formation and maculopathy) and congruence in numbers of microaneurysms, haemorrhages, and exudates reported. RESULTS--Camera screening missed two cases of new vessel formation and did not identify a further 12 but indicated a need for referral. Ophthalmoscopy missed five cases of new vessel formation and indicated a need for referral in another four for other reasons. Maculopathy was reported in 147 eyes with camera screening alone and 95 eyes by ophthalmoscopy only (chi 2 = 11.2; p less than 0.001), in 66 and 29 of which respectively maculopathy was subsequently confirmed. Overall, 38 eyes received laser treatment for maculopathy after detection by camera screening compared with 17 after ophthalmoscopic detection (chi 2 = 8.0; p less than 0.01). Camera screening underestimated numbers of microaneurysms (chi 2 = 12.9; p less than 0.001) and haemorrhages (chi 2 = 7.4; p less than 0.01) and ophthalmoscopy underestimated hard exudates (chi 2 = 48.2; p less than 0.001). CONCLUSIONS--Non-mydriatic Polaroid retinal photography is at least as good as ophthalmoscopy with mydriasis in routine diabetic clinics in identifying new vessel formation and absence of retinopathy and is significantly better in detecting exudative maculopathy.     

Assessment of non-mydriatic fundus photography in detection of diabetic retinopathy.

Non-mydriatic retinal photography with later interpretation of the photographs was assessed as a screening method for the detection of diabetic retinopathy; when compared with an ophthalmologist''s clinical assessment in a random group of 62 diabetic patients it was accurate (false negative 6.8%, false positive 2%) and sensitive (sensitivity 96%, specificity 98%). The assessment of further management required based on analysis of the photographs was 96.5% in agreement with the further management suggested by the ophthalmologist after direct clinical assessment of the patient. If this technique were used to screen patients in a typical diabetic clinic the predicted positive accuracy rate would be 84% and the predicted negative accuracy rate 99.5%.     

Screening of diabetics for retinopathy by ophthalmic opticians.

Diabetes mellitus is a major cause of blindness in England and Wales in those aged between 30 and 64. Photocoagulation can frequently prevent blindness provided the retinopathy is detected at an appropriate stage but unfortunately the benefits are small if the changes are advanced. Early detection of diabetic retinopathy by regular examination is needed. We have shown that ophthalmic opticians have the skill to detect retinal changes at a treatable stage. Out of 844 eye checks, 80 were reported by ophthalmic opticians to justify referral to an ophthalmologist and 20 of these required photocoagulation treatment. Of a sample of 197 patients rechecked by an ophthalmologist reported by ophthalmic opticians not to justify referral, only one needed treatment. With local agreement this system of detecting retinopathy could be easily applied anywhere in the United Kingdom. No extra personnel or facilities are needed.     

SDOCT imaging to identify macular pathology in patients diagnosed with diabetic maculopathy by a digital photographic retinal screening programme

Introduction

Diabetic macular edema (DME) is an important cause of vision loss. England has a national systematic photographic retinal screening programme to identify patients with diabetic eye disease. Grading retinal photographs according to this national protocol identifies surrogate markers for DME. We audited a care pathway using a spectral-domain optical coherence tomography (SDOCT) clinic to identify macular pathology in this subset of patients.

Methods

A prospective audit was performed of patients referred from screening with mild to moderate non-proliferative diabetic retinopathy (R1) and surrogate markers for diabetic macular edema (M1) attending an SDOCT clinic. The SDOCT images were graded by an ophthalmologist as SDOCT positive, borderline or negative. SDOCT positive patients were referred to the medical retina clinic. SDOCT negative and borderline patients were further reviewed in the SDOCT clinic in 6 months.

Results

From a registered screening population of 17 551 patients with diabetes mellitus, 311 patients met the inclusion criteria between (March 2008 and September 2009). We analyzed images from 311 patients’ SDOCT clinic episodes. There were 131 SDOCT negative and 12 borderline patients booked for revisit in the OCT clinic. Twenty-four were referred back to photographic screening for a variety of reasons. A total of 144 were referred to ophthalmology with OCT evidence of definite macular pathology requiring review by an ophthalmologist.

Discussion

This analysis shows that patients with diabetes, mild to moderate non-proliferative diabetic retinopathy (R1) and evidence of diabetic maculopathy on non-stereoscopic retinal photographs (M1) have a 42.1% chance of having no macular edema on SDOCT imaging as defined by standard OCT definitions of DME when graded by a retinal specialist. SDOCT imaging is a useful adjunct to colour fundus photography in screening for referable diabetic maculopathy in our screening population.     

Possible new method to improve detection of diabetic retinopathy: Polaroid non-mydriatic retinal photography.

Two retinal cameras (Canon CR2 45NM and CR3 45NM) have recently become available and are capable of producing an instant colour photography of a 45 degree field of retina, including the macula and optic disc, without dilatation of the pupils being necessary. The ability of each camera to detect diabetic retinopathy was compared with that of doctors in diabetic clinics using ophthalmoscopy during busy clinic hours. The CR3 was found to be considerably superior to the CR2 in terms of quality of photograph because it can use a smaller pupil. Overall, the detection rate of the camera was more than four times higher than that of ophthalmoscopy through undilated pupils and more than twice as high as that of ophthalmoscopy through dilated pupils. Lesions missed by ophthalmoscopy but detected by the camera included soft exudates and circinate rings of hard exudates, sometimes encroaching on the macula. Though various aspects of this system of screening for diabetic retinopathy, in particular its ability to detect new retinal vessels, have not yet been assessed, the system may prove beneficial in the detection and monitoring of diabetic retinopathy.     

Validation of Smartphone Based Retinal Photography for Diabetic Retinopathy Screening

Aim

To evaluate the sensitivity and specificity of “fundus on phone’ (FOP) camera, a smartphone based retinal imaging system, as a screening tool for diabetic retinopathy (DR) detection and DR severity in comparison with 7-standard field digital retinal photography.

Design

Single-site, prospective, comparative, instrument validation study.

Methods

301 patients (602 eyes) with type 2 diabetes underwent standard seven-field digital fundus photography with both Carl Zeiss fundus camera and indigenous FOP at a tertiary care diabetes centre in South India. Grading of DR was performed by two independent retina specialists using modified Early Treatment of Diabetic Retinopathy Study grading system. Sight threatening DR (STDR) was defined by the presence of proliferative DR(PDR) or diabetic macular edema. The sensitivity, specificity and image quality were assessed.

Results

The mean age of the participants was 53.5 ±9.6 years and mean duration of diabetes 12.5±7.3 years. The Zeiss camera showed that 43.9% had non-proliferative DR(NPDR) and 15.3% had PDR while the FOP camera showed that 40.2% had NPDR and 15.3% had PDR. The sensitivity and specificity for detecting any DR by FOP was 92.7% (95%CI 87.8–96.1) and 98.4% (95%CI 94.3–99.8) respectively and the kappa (ĸ) agreement was 0.90 (95%CI-0.85–0.95 p<0.001) while for STDR, the sensitivity was 87.9% (95%CI 83.2–92.9), specificity 94.9% (95%CI 89.7–98.2) and ĸ agreement was 0.80 (95%CI 0.71–0.89 p<0.001), compared to conventional photography.

Conclusion

Retinal photography using FOP camera is effective for screening and diagnosis of DR and STDR with high sensitivity and specificity and has substantial agreement with conventional retinal photography.     

Quality of screening for diabetic retinopathy in the Rijeka region of Croatia

The aim of this study was to compare the quality of screening for diabetic retinopathy in cities of Rijeka and Zagreb, Croatia. Review of a random sample of 500 diabetic patient records and prospective ophthalmologic survey of 466 randomly selected diabetic patients in a secondary level diabetologic service in Rijeka (coastal region of Croatia). The main outcome measures were proportion of diabetic patient records with notes on ophthalmologic examination; rate of diabetic patients involved with screening for diabetic retinopathy; comparison with rates in Zagreb (Croatian capital). A total of 67% patients visited the ophthalmologist at least once after diagnosed with diabetes, and notes on ophthalmologic examination were found in only 28% patient records. Fifty percent of patients underwent an ophthalmologic examination within two years. Only one third of patients diagnosed with DM in last two years visited the ophthalmologist within this time, and 14% of patients older than 50 years never visited the ophthalmologist. Model of screening for diabetic retinopathy in Croatia works better in Zagreb than in Rijeka region, and needs certain improvements. The authors suggested modern methods of screening, the incorporation of the mechanisms of quality control, the obligatory reporting of newly diagnosed diabetic patients to the national registry, and the direct referral from diabetologist to ophthalmologist.     

The English national risk-reduction programme for preservation of sight in diabetes

This paper discusses the new national guidelines for a systematic screening programme to detect sight-threatening diabetic retinopathy in the population of people with diabetes in England. A review of the literature examines the evidence base to support screening interventions and effective management and treatments in diabetic retinopathy. The current evidence supports the establishment of a digital retinal photography system using pupil dilation. A Policy Advisory Group has been formulated by the National Screening Committee to guide the meeting of this target in England. A conclusion is made that with increased effort and organisation, health care professionals can ensure that the screening programme is successfully implemented and rates of visual impairment and blindness caused by diabetic retinopathy can be reduced significantly. (Mol Cell Biochem 261: 183–185, 2004)     

The English national risk-reduction programme for preservation of sight in diabetes

This paper discusses the new national guidelines for a systematic screening programme to detect sight-threatening diabetic retinopathy in the population of people with diabetes in England. A review of the literature examines the evidence base to support screening interventions and effective management and treatments in diabetic retinopathy. The current evidence supports the establishment of a digital retinal photography system using pupil dilation. A Policy Advisory Group has been formulated by the National Screening Committee to guide the meeting of this target in England. A conclusion is made that with increased effort and organisation, health care professionals can ensure that the screening programme is successfully implemented and rates of visual impairment and blindness caused by diabetic retinopathy can be reduced significantly.     

Automated Multi-Lesion Detection for Referable Diabetic Retinopathy in Indigenous Health Care

Diabetic Retinopathy (DR) is a complication of diabetes mellitus that affects more than one-quarter of the population with diabetes, and can lead to blindness if not discovered in time. An automated screening enables the identification of patients who need further medical attention. This study aimed to classify retinal images of Aboriginal and Torres Strait Islander peoples utilizing an automated computer-based multi-lesion eye screening program for diabetic retinopathy. The multi-lesion classifier was trained on 1,014 images from the São Paulo Eye Hospital and tested on retinal images containing no DR-related lesion, single lesions, or multiple types of lesions from the Inala Aboriginal and Torres Strait Islander health care centre. The automated multi-lesion classifier has the potential to enhance the efficiency of clinical practice delivering diabetic retinopathy screening. Our program does not necessitate image samples for training from any specific ethnic group or population being assessed and is independent of image pre- or post-processing to identify retinal lesions. In this Aboriginal and Torres Strait Islander population, the program achieved 100% sensitivity and 88.9% specificity in identifying bright lesions, while detection of red lesions achieved a sensitivity of 67% and specificity of 95%. When both bright and red lesions were present, 100% sensitivity with 88.9% specificity was obtained. All results obtained with this automated screening program meet WHO standards for diabetic retinopathy screening.     

Prevention of blindness by screening for diabetic retinopathy: a quantitative assessment.

Diabetic retinopathy is an important cause of blindness in the Western World. A review of the randomised trials of laser photocoagulation of the retina as a method of preventing blindness from this disorder showed that this treatment is very effective, reducing the risk of blindness by 61% in a treated eye. As only one eye is needed for sight the reduction in blindness in a population will be greater than 61% because the effect of treatment in one eye is not always identical with the effect in the other eye. For analysis this reduction was taken as 73%, representing the average of the minimum and maximum estimates (61% and 85%). The effectiveness of this treatment suggests that there is the potential for a national screening programme to bring about a major reduction in blindness from this cause. A quantitative assessment of the effect of screening indicated that a programme in which patients with diabetes mellitus are systematically referred to ophthalmic opticians for a retinal examination could detect 88% of all diabetics with serious retinopathy and that 87% of these cases would be treatable. Screening and early treatment of retinopathy would prevent deterioration of visual acuity and could reduce the risk of blindness due to diabetic retinopathy by an estimated 56% (0.73 X 0.88 X 0.87). The findings suggest that an effectively managed community based screening programme encompassing detection, referral, treatment, and follow up would prevent about 260 new cases of blindness in diabetics under the age of 70 each year in England and Wales. This would represent over 10% of all cases of blindness in adults in this age group.     

Assessment of automated disease detection in diabetic retinopathy screening using two-field photography

Aim

To assess the performance of automated disease detection in diabetic retinopathy screening using two field mydriatic photography.

Methods

Images from 8,271 sequential patient screening episodes from a South London diabetic retinopathy screening service were processed by the Medalytix iGrading™ automated grading system. For each screening episode macular-centred and disc-centred images of both eyes were acquired and independently graded according to the English national grading scheme. Where discrepancies were found between the automated result and original manual grade, internal and external arbitration was used to determine the final study grades. Two versions of the software were used: one that detected microaneurysms alone, and one that detected blot haemorrhages and exudates in addition to microaneurysms. Results for each version were calculated once using both fields and once using the macula-centred field alone.

Results

Of the 8,271 episodes, 346 (4.2%) were considered unassessable. Referable disease was detected in 587 episodes (7.1%). The sensitivity of the automated system for detecting unassessable images ranged from 97.4% to 99.1% depending on configuration. The sensitivity of the automated system for referable episodes ranged from 98.3% to 99.3%. All the episodes that included proliferative or pre-proliferative retinopathy were detected by the automated system regardless of configuration (192/192, 95% confidence interval 98.0% to 100%). If implemented as the first step in grading, the automated system would have reduced the manual grading effort by between 2,183 and 3,147 patient episodes (26.4% to 38.1%).

Conclusion

Automated grading can safely reduce the workload of manual grading using two field, mydriatic photography in a routine screening service.     

Prevalence of retinopathy in a diabetic clinic.

In a prospective study lasting 14 months an attempt was made to measure the visual acuity and examine the fundi, after mydriasis, of all patients attending the diabetic clinic of a district general hospital. Of 704 patients, 160 (22.7%) had some evidence of retinopathy, and 52 (7.4%) of these were already attending an ophthalmologist. A further 18 (2.6%) were known to have retinopathy and were being followed up in the diabetic clinic. Ninety (12.8%) new patients with diabetic retinopathy were discovered. Most had minimal changes, but 30 (4.3%) were considered to have changes severe enough to be referred to an ophthalmologist. Twenty-two (2.1%) underwent, or were awaiting, photocoagulation, and half of these had had no visual symptoms when first seen. Although some of these patients were already being treated or observed for retinopathy, it is encouraging that relatively few new patients needing treatment for retinopathy were discovered. If retinopathy could be detected early enough physicians might be able to deal with it and so ease pressure on ophthalmological services.     

Use of mobile screening unit for diabetic retinopathy in rural and urban areas.

OBJECTIVES--To compare the effectiveness of a mobile screening unit with a non-mydriatic polaroid camera in detecting diabetic retinopathy in rural and urban areas. To estimate the cost of the service. DESIGN--Prospective data collection over two years of screening for diabetic retinopathy throughout Tayside. SETTING--Tayside region, population 390,000, area 7770 km2. SUBJECTS--961 patients in rural areas and 1225 in urban areas who presented for screening. MAIN OUTCOME MEASURES--Presence of diabetic retinopathy, need for laser photocoagulation, age, duration of diabetes, and diabetic treatment. RESULTS--Compared with diabetic patients in urban areas, those in rural areas were less likely to attend a hospital based diabetic clinic (46% (442) v 86% (1054), p < 0.001); less likely to be receiving insulin (260 (27%) v 416 (34%), p < 0.001 and also after correction for differences in age distribution); more likely to have advanced (maculopathy or proliferative retinopathy) diabetic retinopathy (13% (122) v 7% (89), p < 0.001); and more likely to require urgent laser photocoagulation for previously unrecognised retinopathy (1.4% (13) v 0.5% (6), p < 0.02). The screening programme cost 10 pounds per patient screened and 1000 pounds per patient requiring laser treatment. CONCLUSION--The mobile diabetic eye screening programme detected a greater prevalence of advanced retinopathy in diabetic patients living in rural areas. Patients in rural areas were also more likely to need urgent laser photocoagulation. Present screening procedures seem to be less effective in rural areas and rural patients may benefit more from mobile screening units than urban patients.     

Medical housing "lines".

General practitioners are often asked for medical certificates (housing "lines") by applicants for council housing who claim to have medical problems requiring housing priority. The results of a survey by questionnaire showed that general practitioners in Edinburgh do not know how the housing system works and that they seem to overestimate their patients'' chances of obtaining suitable council housing. General practitioners need to know how the housing system works, and communication between general practitioners and housing departments should be improved. A comparison was also made between the number of medical points awarded by a community medicine specialist and a group of general practitioners who had written housing "lines" for their patients. The general practitioners tended to award more points than the specialist. Social priority for housing should be recognised as an independent factor and a new category of top social priority added.     

Study of diagnostic accord between general practitioners and an ophthalmologist.

OBJECTIVES--To identify diagnostic accord and disagreement between general practitioners and an ophthalmologist and thereby determine how undergraduate and non-specialist postgraduate ophthalmic training could be improved. DESIGN--Comparison of diagnosis of presenting conditions by general practitioners and one ophthalmologist in patients consulting general practitioners for ophthalmic problems during March 1989 to February 1990. SETTING--12 general practices in west Nottingham. PATIENTS--1474 patients presenting to the study general practitioners with new ophthalmic conditions or new episodes of recurrent conditions. MAIN OUTCOME MEASURES--Diagnoses of general practitioners and ophthalmologist. RESULTS--1121 (76%) of patients with eye problems agreed to see the ophthalmologist and most were seen within three days. Sufficient data for comparison were available on 1103 patients. Diagnostic agreement was found in 638 cases (58%), but potentially serious misdiagnosis was found in only 15 cases; management in three of these cases would have ensured later identification. Most commonly confused conditions were infective and allergic conjunctivitis, blepharitis, and dry eyes. General practitioners assessed visual acuity in only 114 cases yet eight of the 15 patients seriously misdiagnosed had reduced acuity, an important diagnostic sign. CONCLUSIONS--Most ophthalmic disease seen in general practice does not require specialised equipment for diagnosis. Most cases of misdiagnosis have no serious consequences for the patient. Undergraduate and postgraduate training in ophthalmology should ensure that common conditions can be easily differentiated and more serious conditions identified and referred.     

Funduscopic examination of patients with diabetes who are admitted to hospital.

The charts of 123 patients with diabetes mellitus who were admitted to hospital were reviewed; 35 (28%) did not undergo funduscopic examination to detect diabetic retinopathy, and in 27 (22%) the examination was inadequate. Only four patients were referred to an ophthalmologist. Evidence of nephropathy and admission for diabetes control did not increase the probability of funduscopic examination. The findings suggest that house staff lack awareness of the natural history of diabetic retinopathy and of the success of current treatment. Annual funduscopic examination by an ophthalmologist in patients with diabetes is recommended, from the time of diagnosis in those with type II diabetes and starting 8 to 10 years after diagnosis in those with type I diabetes.     

Detection of Neovascularization Based on Fractal and Texture Analysis with Interaction Effects in Diabetic Retinopathy

Diabetic retinopathy is a major cause of blindness. Proliferative diabetic retinopathy is a result of severe vascular complication and is visible as neovascularization of the retina. Automatic detection of such new vessels would be useful for the severity grading of diabetic retinopathy, and it is an important part of screening process to identify those who may require immediate treatment for their diabetic retinopathy. We proposed a novel new vessels detection method including statistical texture analysis (STA), high order spectrum analysis (HOS), fractal analysis (FA), and most importantly we have shown that by incorporating their associated interactions the accuracy of new vessels detection can be greatly improved. To assess its performance, the sensitivity, specificity and accuracy (AUC) are obtained. They are 96.3%, 99.1% and 98.5% (99.3%), respectively. It is found that the proposed method can improve the accuracy of new vessels detection significantly over previous methods. The algorithm can be automated and is valuable to detect relatively severe cases of diabetic retinopathy among diabetes patients.     

Prescribing at the hospital-general practice interface. II: Impact of hospital outpatient dispensing policies in England on general practitioners and hospital consultants.

OBJECTIVE--To assess the impact on general practitioners and hospital consultants of hospital outpatient dispensing policies in England. DESIGN--Postal questionnaire and telephone interview survey of general practitioners and hospital consultants in January 1991. SETTING--94 selected major acute hospitals in England. PARTICIPANTS--20 general practitioners in the vicinity of each of 94 selected hospitals and eight consultants from each, selected by chief pharmacists. MAIN OUTCOME MEASURES--Proportions of general practitioners unable to assume responsibility for specialist drugs and of consultants wishing to retain responsibility; association between dispensing restrictions and the frequency of general practitioners being asked to prescribe hospital initiated treatments. RESULTS--Completed questionnaires were obtained from 1207 (64%) of 1887 general practitioners and 457 (63%) of 729 consultants. 570 (46%) general practitioners felt unable to take responsibility for certain treatments, principally because of difficulty in detecting side effects (367, 30%), uncertainty about explaining treatment to patients (332, 28%), and difficulty monitoring dosage (294, 24%). Among consultants 328 (72%) wished to retain responsibility, principally because of specialist need for monitoring (93, 20%), urgent need to commence treatment (64, 14%), and specialist need to initiate or stabilise treatment (63, 14%). The more restricted the drug supply to outpatients, the more frequently consultants asked general practitioners to prescribe (p less than 0.01) and complete a short course of treatment initiated by the hospital (p less than 0.001). CONCLUSIONS--Restrictive hospital outpatient dispensing shifts clinical responsibility on to general practitioners. Hospital doctors should be able to retain responsibility for prescribing when the general practitioner is unfamiliar with the drug or there is a specialist need to initiate, stabilise, or monitor treatment.