Evaluation of a non-mydriatic camera in Indian and European diabetic patients

Comparative analysis of two retinal fractures with ultrabroad‑angle fundus photography systems

The aim of the present study was to compare the performance of the Opel Panorama 200 and Zeiss Clarus 500 (Carl Zeiss AG) systems in diagnosing retinal fractures. Human subjects were selected from 298 fundus examinations (531 eyes) in ophthalmology from February 2021 to June 2021, including 68 patients with retinal fissures (95 eyes). All fundus tests were performed with Opel Panoramic 200. Zeiss Clarus 500 (Carl Zeiss AG) fundus photography, slit-lamp full retinal lens (Ocular Mainster Wide Field; Ocular Instruments), and retinal laser photocoagulation was performed for all affected eyes. The diagnostic sensitivity of the two examination methods was compared, and their sensitivities for posterior retina, peripheral nose, crystal eye, cataract, positive experiment, and myopia testing were compared. In all, 68 patients (95 eyes) were clinically examined and treated 112 laser times. For retinal fractures, the Opel Panorama 200 used a check sensitivity of 89.5%, and the Clarus 500 check had a sensitivity of 94.7%, with the difference being non-significant (P=0.358). Moreover, Clarus 500 diagnosed the sensitivity of the temporal periphery significantly higher than that of Opel Panorama 200 (P=0.048). Opel Panorama 200 displayed statistically significant sensitivity compared with Clarus 500 diagnosis with crystalline and crystal fewer eyes (P>0.05); Clarus 500 sensitivity for cataract diagnosis (crystal turbidity level 3 and above) was significantly higher than that of Opel Panorama 200 (P=0.033). Opel Panoramic 200 displayed significant sensitivity to ocular myopia and medium to moderate myopia (P>0.05). Clarus 500 diagnosed high myopia with a significantly higher sensitivity than Opel Panorama 200 (P=0.045). Opel Panorama 200 and Zeiss Clarus 500 displayed the same level of sensitivity to retinal fissures, with improved sensitivity in refractive turbidity and for retinal fissures located in the far periphery of the temporal side.

Review of retinal cameras for global coverage of diabetic retinopathy screening

The global burden of diabetes has resulted in an increase in the prevalence of diabetic retinopathy (DR), a microvascular complication of diabetes. Lifelong repetitive screening for DR is essential for early detection and timely management to prevent visual impairment due to the silent sight-threatening disorder. Colour fundus photography (CFP) is helpful for documentation of the retinopathy as well as for counselling the patient. CFP has established roles in DR screening, detection, progression and monitoring of treatment response. DR screening programmes use validated mydriatic or non-mydriatic fundus cameras for retinal imaging and trained image graders identify referable DR. Smartphone-based fundus cameras and handheld fundus cameras that are cost-effective, portable and easy to handle in remote places are gaining popularity in recent years. The images captured with these low-cost devices can be immediately sent to trained ophthalmologists for grading of DR. Recent increase in numbers of telemedicine programmes based on imaging with digital fundus cameras and remote interpretation has facilitated larger population coverage of DR screening and timely referral of those with sight-threatening DR to ophthalmologists. Good-quality retinal imaging and accurate diagnosis are essential to reduce inappropriate referrals. Advances in digital imaging such as ultra-wide field imaging and multi-modal imaging have opened new avenues for assessing DR. Fundus cameras with integrated artificial intelligence (AI)-based automated algorithms can also provide instant DR diagnosis and reduce the burden of healthcare systems. We review the different types of fundus cameras currently used in DR screening and management around the world.

My 40-year journey in diabetes research: The power of collaboration

This article describes a 40 year journey in diabetes research of an Indian diabetologist, starting as an undergraduate medical student. The article describes how collaborations with multiple stake-holders is necessary if one is to advance one's research from the simple studies that one starts with and take it to higher and higher levels. It is also essential that the seeds for doing research are planted early in a medico's life even during undergraduate days, as only then will more doctors take up medical research as a career. Finally, the article demonstrates how it is possible to do good quality research in India if one has the passion and sustained interest in the field even if one is not in a university or academic setup.

Sensitivity and specificity of nonmydriatic digital imaging in screening diabetic retinopathy in Indian eyes

Background:

Nonmydriatic digital imaging (NMDI) is ideal for screening diabetic retinopathy (DR), but its use in Indian eyes has not been evaluated.

Aim:

The aim was to evaluate the sensitivity and specificity of NMDI as a screening tool in detecting DR in Indian eyes.

Design:

A prospective, nonrandomized, noncomparative, noninterventional study.

Materials and Methods:

A total of 500 diabetic patients visiting the endocrinology clinic (September 2008-June 2010) underwent NMDI (Zeiss Procam), followed by routine dilated fundus photography (FP; Zeiss Visupac 450+) of 345° retinal fields (1) optic disc and macula, (2) superotemporal, and (3) nasal to optic disc. Two-masked retina specialists graded the images for quality and severity of DR, and compared between NMDI and dilated FP.

Statistical Analysis:

SPSS Windows 17 for version.

Results:

Mean age was 52.97 ± 13.46 years (306 males: 194 females). The rate of ungradable images was 30.6% and 31% by the two observers. By observer 1, the sensitivity and specificity of detecting any DR was 58.8% and 69.1%, respectively, (κ = 0.608) and sight-threatening DR (STDR) was 63.1% and 68.9%, respectively, (κ = 0.641). By observer 2, the sensitivity and specificity was 57.3% and 68.3%, respectively, for any DR (κ = 0.593) and 62.8% and 68.3%, respectively, for STDR (κ = 0.637). The level of agreement between two observers was high (κ = 0.96).

Conclusion:

A high rate of poor quality photographs and low sensitivity limited the use of NMDI as a perfect screening system, particularly in dark iris population with diabetes as seen in Indian eyes.

Low cumulative incidence of proliferative retinopathy in childhood-onset type 1 diabetes: a 24-year follow-up study

AIMS/HYPOTHESIS

We estimated cumulative incidence of proliferative diabetic retinopathy (PDR) and risk factors for developing diabetic retinopathy (DR) in childhood-onset type 1 diabetes.

MATERIALS AND METHODS

A sample of 294 patients with childhood-onset type 1 diabetes (<15 years) diagnosed in Norway between 1973 and 1982 was examined for retinopathy at baseline between 1989 and 1990 and at follow-up from 2002 to 2003. At follow-up, mean age was 33 years (range: 21-44), mean diabetes duration 24 years (19-30) and total person-time contributed 7,152 person-years. Retinal photographs were taken at baseline and follow-up. Associations between baseline factors and PDR were estimated using Cox regression models.

RESULTS

Overall, 262 of 294 (89.1%) developed DR from diabetes onset, of whom 31 developed PDR. The 25-year cumulative incidence of PDR was 10.9% (95% CI 7.3-14.5). Among 194 without retinopathy at baseline, 163 (84%) developed DR and nine (5%) progressed to PDR. Among 97 patients with non-proliferative DR at baseline, 19 (20%) progressed to PDR. Significant predictors for developing PDR were retinopathy at baseline (relative risk [RR]=3.71, 95% CI 1.59-8.68), HbA(1c) (RR=2.05, 1.44-2.93), and triglycerides (RR=1.55, 1.06-1.95).

CONCLUSIONS/INTERPRETATION

Nine out of every ten patients diagnosed with type 1 diabetes developed DR, but only one out of ten developed PDR within their first 25 years of diabetes duration. The cumulative incidence of PDR is lower than previously reported from other countries. Potentially modifiable risk factors predict the development of DR and PDR.

Screening for sight-threatening diabetic retinopathy: comparison of fundus photography with automated color contrast threshold test

PURPOSE

To compare tritan contrast threshold (TCT) with fundus photography in screening for sight-threatening diabetic retinopathy (STDR), before significant visual loss.

DESIGN

Prospective, comparative study.

METHODS

A total of 510 consenting diabetic patients attending a hospital-based photographic screening clinic were recruited over a 2-year period. Exclusion criteria included visual acuity of worse than 6/9, previous photocoagulation, and a history of previous eye disease known to affect color vision. The automated TCT test was performed using a computerized cathode ray tube-based technique. Retinal photography was performed using a Polaroid mydriatic fundus camera with a 45 degrees field. Grading of diabetic retinopathy was carried out by an ophthalmologist using slit-lamp biomicroscopy and a 78-diopters lens. Assessments of sensitivity, specificity, and predictive values for both fundus photography and the TCT test were made.

RESULTS

Both the fundus photography and TCT test correlated significantly with the presence of STDR (P <.0001, chi(2) test). The TCT test yielded a sensitivity of 94% (95% confidence interval [CI], 73%- 100%) and a specificity of 95% (95% CI, 92%- 96%) for detection of STDR compared with a sensitivity of 88% (95% CI, 66%-97%) and a specificity of 95% (95% CI, 93%-97%) with fundus photography. Combined modality improved overall screening performance.

CONCLUSION

The TCT assessment is an effective and clinically viable technique, in comparison with fundus photography, to screen for STDR among a diabetic population. Additionally, our results also showed that combining the TCT test with fundus photography greatly increases the performance of screening for STDR.

Use of telemedicine in screening for diabetic retinopathy

BACKGROUND

A diabetic retinopathy screening program was introduced in September 2000 at a university-affiliated hospital in Montreal to meet the demands of an overburdened health care system. In this article we describe our initial experience with this program.

METHODS

A Canon CR6-45NM nonmydriatic 45 degrees camera was installed in the outpatient endocrinology clinic of the hospital. All patients who visited the clinic between September 2000 and January 2001 agreed to participate in the program. For each patient, a short questionnaire (age, sex, type of diabetes mellitus, time since diagnosis, prior retinal laser therapy and presence of end-organ involvement) was filled in. Subsequently at least two photographs were obtained of each eye. The photographs were sent via the hospital intranet to a retinal specialist within the hospital. The specialist reviewed the images unchanged and sent a report (grading of the level of diabetic retinopathy, presence or absence of macular hard exudates, quality of the images obtained and follow-up recommendations) via the hospital intranet to the endocrinology service. If the images were judged to be of poor quality and could not be read by the retina specialist, the patient was asked to see his or her regular ophthalmologist.

RESULTS

Images of 830 eyes of 415 patients (211 men and 204 women with a mean age of 57.5 years) were obtained. Most (83.6%) had type 2 diabetes. The average duration of disease was 13.3 years. Macular hard exudates were observed in 50 eyes (6.0%). Nonproliferative diabetic retinopathy was noted in 117 eyes (14.1%) and proliferative diabetic retinopathy in 15 eyes (1.8%). Unexpected findings included epiretinal membranes (in three eyes), macular holes (in two), bilateral cotton-wool spots (in one patient) and central retinal vein occlusion (in one eye). Overall, 10% of the patients were referred to a retina specialist based on the screening photographs. The main difficulty encountered with the screening program was image inconsistency. Overall, 35% of the images graded were felt to be of poor quality, the most common reason being poor exposure (84.4%). The quality of the images improved significantly over the study period (p < 0.01). Images obtained from patients aged 65 years or more were consistently poorer than those obtained from patients less than 65 years of age (p < 0.001).

INTERPRETATION

Despite the imperfections of such a system, our experience was favourable, allowing us to screen large numbers of patients in a cost-effective, reliable manner.

Changing times for the management of diabetic retinopathy

Laser photocoagulation has led a revolution in the management of diabetic retinopathy. Scatter photocoagulation and focal photocoagulation has been shown to be effective in reducing vision loss. Just as dramatic as laser photocoagulation, medical treatment has led another revolution in the treatment of diabetic retinopathy. Good glycemic, blood pressure, and lipid control have contributed to further reduce vision loss and laser photocoagulation. In the very near future, there will be significant advances in pharmacologic treatment of diabetic retinopathy. Treatment with antioxidants, agents inhibiting hyperglycemia-induced protein kinase activity, and other agents will likely prevent the development/progression of retinopathy. Because pharmacologic agents are aimed at the prevention of retinopathy, patients with retinopathy will need to be examined earlier to diagnose retinopathy at earlier stages. To maximize the opportunity for earlier diagnosis, ophthalmologist may need to adopt screening strategies to identify patients most likely to benefit from these new treatments.

Screening and follow-up of diabetic retinopathy using a new mosaic 9-field fundus photography system

AIM

To evaluate the clinical usefulness of a newly developed fundus photographing system and assess its applicability to telemedicine.

METHODS

Nine overlapping 45 degrees fundus photographs were taken by a new camera equipped with nine internal fixation targets to provide standardized 9-field photographs. The digitally stored images were either edited in 3x3 form or reconstructed as collage (9F) and compared to the ophthalmological examination (OP) and single-field non-mydriatic photography (SC). In telemedicine, 9-field images derived from 61 adolescent diabetics were sent to ophthalmologists over an analog phone line.

RESULTS

The sensitivities of the examinations by 9F without and with mydriasis (78 and 82%) were equivalent to OP (84%) and superior to SC (64%). The diagnosis of severity by 9F was also comparable to those by OP, whereas SC tended to underestimate the severity. An average of 1 min 19 s was required to send one edited 9-field photography (average size 259+/-30 KB) over the Internet. Twelve of these eyes were diagnosed as diabetic retinopathy on a desktop monitor whereas SC gave only seven.

CONCLUSION

This new 9-field fundus photography system can be appropriate for the screening and follow-up of diabetic retinopathy in adult and adolescent diabetic subjects, especially when applied to telemedicine over the Internet.

Effectiveness of optometrist screening for diabetic retinopathy using slit-lamp biomicroscopy

PURPOSE

To assess the effectiveness of optometrists as screeners for diabetic retinopathy using slit-lamp binocular indirect ophthalmoscopy through dilated pupils.

METHODS

Prospective study of a screening scheme. Screening was performed by 27 locally accredited optometrists in their practice. The referral protocol used a new simple grading system of retinopathy, especially designed for use in an optometrist screening programme. All positive referrals and 10% of negative referrals were reexamined by an ophthalmologist. Sensitivity, specificity, likelihood ratios and technical failure rates were calculated.

RESULTS

The optometrists screened 4904 people with diabetes in 18 months. 'Subthreshold' (screen negative) reports accounted for 4438 (90.5% of 4904); 429 (9.67%) of these were re-examined at secondary screening. There was disagreement regarding grading in 13 patients, of whom 5 (1.16% of 429) had sight-threatening retinopathy (STDR); this extrapolates to 52 patients if all the 4438 test-negatives had been examined. Of the 371 'threshold' patients, 112 (30.18%) were false positives; the commonest cause for false positive referral was drusen in patients with background diabetic retinopathy. The sensitivity for identification of STDR was 76% (95% CI 70% to 81%) and specificity 95% (95% CI 95% to 96%). The likelihood ratio of a positive test indicating STDR was 16.54 (95% CI 14.17 to 19.23) and that of a negative test 0.25 (95% CI 0.20 to 0.32). The technical failure rate was 0.2%.

CONCLUSIONS

Suitably trained and accredited community optometrists performed well when screening for diabetic retinopathy using slit-lamp biomicroscopy through a dilated pupil. This was facilitated by the use of simple grading and referral criteria. The sensitivity, positive likelihood ratio and specificity were high.

Development of a multi-field fundus photographing system using a non-mydriatic camera for diabetic retinopathy

A new fundus photographing system was developed for diabetic subjects with or without simple diabetic retinopathy using a non-mydriatic fundus camera. Eight internal fixation targets were incorporated in a non-mydriatic fundus camera (TRC-NW5S; TOPCON, Tokyo, Japan), interfaced with a 3CCD color camera. Nine 45 degrees fundus photographs were taken in 22 healthy volunteers and 16 diabetic subjects, and stored as digital images. Fundus images were reconstituted as collages on the monitor and printed out. The combined angle reached 94 degrees in collage, and the average times required for photographing with and without mydriasis were 3 min 26 s and 4 min 36 s, respectively. The concordance of fundus images between the first and second photographs of healthy volunteers with and without mydriasis was 95.4% (n = 22). The quality of the photographs, graded on a five-point scale (5, full) by three doctors, was 4.3 +/- 0.6 in the volunteers without mydriasis, 4.7 +/- 0.4 in the diabetics without mydriasis, and 4.8 +/- 0.3 in the volunteers with mydriasis. In retinas with diabetic retinopathy, the system was able to depict microaneurysms, hemorrhages, hard exudates and soft exudates. This new system was satisfactory for the screening and follow-up of diabetic retinopathy.

Prevalence of retinopathy in non insulin dependent diabetes mellitus at a diabetes centre in southern India

A cohort of 6792 NIDDM patients attending a diabetes centre at Madras in South India was screened using a combination of retinal photography and clinical examination by retinal specialists. A total of 2319 patients (34.1%) had evidence of retinopathy. This included 2090 patients (30.8%) with non-proliferative diabetic retinopathy including 435 patients (6.4%) with maculopathy and 229 patients (3.4%) with proliferative diabetic retinopathy. Multiple logistic regression analyses showed that duration of diabetes, glycosylated haemoglobin, type of treatment (insulin treatment versus non-insulin treatment), systolic and diastolic blood pressures and serum creatinine, showed a positive association with retinopathy while body mass index (BMI) showed an inverse association. The prevalence rates of retinopathy in Southern Indians are comparable to those seen in Europeans. However in view of the high prevalence of diabetes in the Indian sub-continent, diabetic retinopathy could become a formidable challenge in the future.

Vascular complications in long-term south Indian NIDDM of over 25 years' duration

The prevalence of vascular complications was assessed in 726 South Indian non-insulin dependent diabetes mellitus (NIDDM) patients with over 25 years' duration of diabetes. Retinopathy was detected in 52.0% of patients which included 41.7% with non-proliferative and 10.3% with proliferative diabetic retinopathy. Nephropathy was present in 12.7% and neuropathy in 69.8% of patients. While 32.8% of patients had ischaemic heart disease, the prevalence of peripheral vascular disease was only 15.4%. Multivariate logistic regression analyses showed that serum creatinine was associated with retinopathy, creatinine and post-prandial plasma glucose with nephropathy and post-prandial plasma glucose and age with neuropathy. This is one of the first reports on vascular complications in long-term diabetes from the Indian sub-continent.

Sensitivity and specificity of photography and direct ophthalmoscopy in screening for sight threatening eye disease: the Liverpool Diabetic Eye Study

OBJECTIVE

To evaluate different methods for community based screening for sight threatening diabetic eye disease.

DESIGN

Prospective study.

SETTING

Mobile screening unit visiting inner city community clinics; hospital assessment clinic (tertiary centre).

SUBJECTS

395 diabetic patients registered with four general practices in an inner city location.

INTERVENTIONS

Community based photography with mydriasis and direct ophthalmoscopy through dilated pupils by an experienced ophthalmologist, both compared with reference standard of slit lamp biomicroscopy by a consultant specialist in medical retinal disease.

MAIN OUTCOME MEASURES

Sensitivity and specificity of screening method and prevalence of sight threatening diabetic eye disease (moderate preproliferative retinopathy, circinate maculopathy, exudate within 1 disc diameter of fixation, other diabetes related eye disease).

RESULTS

358 subjects underwent photography, 326 attended hospital clinic for ophthalmoscopy, and six were ungradable on photographs and biomicroscopy, leaving 320 for analysis. Of these 295 (91%) attended clinic within four months of photography. Sensitivity of detection of eye disease by photography was 89% (95% confidence interval 80% to 98%), significantly better than for direct ophthalmoscopy (65% (51% to 79%)). Analysis of patients with false negative results indicated possible improvement of photographic sensitivity to 93% by addition of stereoscopic macular pair photographs. Specificity of detection of sight threatening eye disease was 86% (82% to 90%) for photography and 97% (95% to 99%) for direct ophthalmoscopy.

CONCLUSIONS

Since high sensitivity is essential for an effective screening programme, a photographic method should be considered as preferred option in national, community based screening programmes. Even in the hands of an experienced ophthalmologist, direct ophthalmoscopy is limited by weaknesses inherent to the instrument.

Detection of diabetic retinopathy by scanning laser ophthalmoscopy

A scanning laser ophthalmoscope (SLO) was used to examine the fundi of 54 diabetic patients through undilated pupils and the results compared by an experienced ophthalmologist with clinical examination through dilated pupils to assess the effectiveness of the SLO in detecting diabetic retinopathy. Whilst the SLO was not as good at detecting cotton wool spots and subtle intraretinal microvascular abnormalities, it did not miss any active new vessel formation and all eyes needing treatment would have been referred.

The quality of photographs produced by the non-mydriatic fundus camera in a screening programme for diabetic retinopathy: a 1 year prospective study

A prospective study was performed on the quality of photographs produced by the non-mydriatic fundus camera used in a hospital-based screening programme for diabetic retinopathy. In 1 year 981 binocular patients were photographed. A photograph of acceptable quality was obtained from 90.5% of eyes and 84.4% of patients had an acceptable photograph of both eyes. The photograph of the second eye was more often unacceptable than that of the first. This tendency was significant in females (p = 0.0196) and when considering the sexes together (p = 0.0044), but not significant in males (p = 0.1042). Photographs of unacceptable quality were obtained significantly more often in patients aged over 55 years for both right and left eyes (p = 0.001). An overall improvement in photographic quality might be achieved by allowing full recovery of flash-induced pupil constriction before taking the second photograph and by dilating those aged over 55 years.

The diagnosis of diabetic retinopathy. Ophthalmoscopy versus fundus photography

PURPOSE

To compare fundus photography with ophthalmoscopy in the detection of diabetic retinopathy.

METHODS

Ophthalmoscopy and fundus photographs with a nonmydriatic camera, both performed through dilated pupils, were compared to diagnose retinopathy in a cohort of 410 Oklahoma Indians with noninsulin-dependent diabetes mellitus. A total of 795 eyes were examined using both methods. The mean age of participants was 60.3 years, with a mean duration of diabetes of 17.3 years.

RESULTS

An overall agreement of 86.3% with a kappa statistic kappa of 0.74 was found between ophthalmoscopy and fundus photography with a nonmydriatic camera. For the diagnosis of proliferative diabetic retinopathy, kappa = 0.84 with an agreement of 98.1%. With a total of 61 cases of proliferative retinopathy diagnosed by either method in our study, ophthalmoscopy alone detected 88.5% and fundus photography, 78.7%. When compared on a lesion-by-lesion basis, agreement between the two diagnostic methods was highest for nonproliferative retinopathy, as well as fibrous proliferation.

CONCLUSION

The fundus photography with a nonmydriatic camera, performed with mydriasis, is comparable to ophthalmoscopy for the detection of retinopathy. It may prove to be a suitable, cost-effective method for routine screening in diabetes clinics, provided ophthalmologic referral is ensured for those with a diagnosis of any form of retinopathy, questionable retinopathy, nondiabetic retinopathy, those with poor quality photographs, as well as those with acute changes in visual acuity.

Screening for diabetic retinopathy by general practitioners

To assess the quality of screening for diabetic retinopathy by 19 general practitioners (GPs) using ophthalmoscopy, the GPs' performance was compared with the performance of ophthalmologists. The GPs had received special training in retinal examination. Direct ophthalmoscopy was performed after mydriasis of both eyes. Later, one of the ophthalmologists at the local hospital performed ophthalmoscopy in the same way as the GP. The ophthalmologist's diagnosis was used as the criterion for retinopathy. 252 NIDDM patients were analysed. The ophthalmologists found 23 cases of retinopathy, of which one patient was referred immediately for photocoagulation. The GPs diagnosed 12 and missed 11 of these 23 cases (false negatives): sensitivity 52%. In 37 of the 229 negative cases the GPs reported a retinopathy: specificity 84%. Of the 11 missed cases, 7 had stage I retinopathy and four showed more serious abnormalities (hard and soft exudates, macular oedema) Further training of GPs in the art of ophthalmoscopy is recommended.

A nationwide cross-sectional study of retinopathy and microalbuminuria in young Norwegian type 1 (insulin-dependent) diabetic patients

A nationwide cohort of Type 1 (insulin-dependent) diabetic patients was studied to determine the prevalence of retinopathy and microalbuminuria and to evaluate the association to various risk factors. Of 600 subjects with mean age of 19.8 years (range 8.0-30.3) and a mean duration of diabetes of 10.5 years (range 6.2-17.3), 371 (60%) volunteered for a clinical examination which included fundus photography, timed overnight urine samples for albumin excretion rate, measurement of arterial blood pressure and determination of HbA1c. Retinopathy was found in 122 of 371 patients (32.8%), in 3 of 41 (7.3%) patients aged less than 13 years. The youngest subject with retinopathy was 9.6 years old. Microalbuminuria was found in 44 of 351 patients (12.5%), in 1 of 41 (2.4%) patients aged less than 13 years. The youngest subject with microalbuminuria was 11.5 years old. Mean HbA1c was 8.6% (normal range 4.5-601%). Patients with retinopathy had significantly higher mean age (p = 0.0001), longer mean duration of diabetes (p = 0.0001), higher mean HbA1c (p = 0.009), and higher mean arterial blood pressure (p = 0.0001) compared to patients without retinopathy. In microalbuminuric patients HbA1c (p = 0.001) and mean arterial blood pressure (p = 0.01) were significantly higher compared to non-microalbuminuric patients, but there was no difference in age or diabetes duration. In a multiple logistic regression model, age, HbA1c, duration of diabetes and mean arterial blood pressure were found to be significantly associated with retinopathy, while HbA1c, mean arterial blood pressure and onset before 13.0 years of age were found to be associated with microalbuminuria.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Diabetic retinopathy: methodologies in practice

In France, 20% of patients with diabetes are monitored by diabetologists, and of these 88% are screened for retinopathy by fundal examination with dilation of pupils and 78% by fluorescein angiography. Colour retinal photography is performed in 24% of cases. Eye examination is performed every year in 85% of patients. Diabetic retinopathy is generally considered to be a vascular disease causing loss of vision by macular oedema, vitreous haemorrhage or retinal detachment. However, it may also be a neurosensory disorder, with functional changes occurring before anatomical vascular abnormalities. These include changes in colour vision, contrast sensitivity, dark adaptation, visual-evoked potentials, electroretinography, nyctometry, and fluorometry. The majority of these methods have a predictive value for the late onset of retinopathy in diabetic patients.

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.

Non-mydriatic retinal photography as a screening service for general practitioners

Non-mydriatic retinal photography was offered as a screening service to 37 general practitioners providing diabetes care in their practices. Of 84 patients photographed, 22 had appearances of diabetic retinopathy and these were compared with 25 of the remainder without retinopathy. In only seven of 11 patients with maculopathy or proliferative retinopathy had this been detected by their GP and, likewise, only six of 11 cases of probable background retinopathy had been detected. The mean annual examination rate in general practice was 33 (95% Cl 18-47)%. Of the 18 cases in whom action in response to recommendations for follow-up or referral could be ascertained, 15 (83%) had had the recommendations implemented. Thus, despite the potential risks of false-negative screening using non-mydriatic retinal photography, the technique may improve the comprehensiveness of screening in patients under the care of their GPs.