A telemedical approach to the screening of diabetic retinopathy: digital fundus photography.

Abstract

A Telemedical Approach to the Scre e n i n g of Diabetic Retinopathy: Digital Fundus P h o t o g r a p h y O R I G I N A L A R T I C L E O B J E C T I V E -The importance of screening for diabetic retinopathy has been established, but the best method for screening has not yet been determined. We re p o rt on a trial of assessment of digital photographs by telemedicine compared with standard retinal photographs of the same fields and clinical examination by ophthalmologists. RESEARCH DESIGN AND METHODS-A total of 129 diabetic inpatients were s c reened for diabetic retinopathy by slit-lamp biomicroscopy perf o rmed by an ophthalmologist and by two-field 50° non-stereo digital fundus photographs assessed by six screening centers that received the images by electronic mail. Conventional 35-mm transparencies of the same fields as the digital photographs were assessed by a retinal specialist and served as the re fe rence method for detection of diabetic re t i n o p a t h y. Slit-lamp biomicroscopy was the re f e re n c e method for the detection of macular edema. R E S U LT S -The prevalence of any form of diabetic retinopathy was 30% (n = 35); of sightt h reatening retinopathy including macular edema, the prevalence was 6% (n = 7). The assessment of digital images by the six screening centers resulted in a median sensitivity of 85% and a median specificity of 90% for the detection of moderate nonproliferative or sight-thre a t e ning diabetic re t i n o p a t h y. Clinically significant macular edema (n = 4) was correctly identified in 15 of the 24 grading re p o rts. An additional seven re p o rts re f e rred the patients for furt h e r investigation because of concurrent diabetic re t i n o p a t h y.C O N C L U S I O N S -Te l e s c reening for diabetic retinopathy by an assessment of two-field 50°n o n -s t e reo digital images is a valid screening method. Although detection of clinically significant macular edema using biomicroscopy is superior to digital or standard non-stereo photographs, only few patients with sight-threatening diabetic retinopathy are missed. E m e r g i n g T r e a t m e n t s a n d T e c h n o l o g i e s Diabetes Care 346DIABETES CARE, VOLUME 23, NUMBER 3, MARCH 2000 Telemedical screening of diabetic retinopathyThe 65 patients who did not part i c ipate were older (59.0 ± 16.0 years), had a longer duration of diabetes (17.6 ± 12.4 years), and had more severe re t i n o p a t h y (43% no, 33% mild or moderate, and 24% s i g h t -t h reatening diabetic retinopathy). The p ro p o rtion of men (50%) and patients with type 2 diabetes (58%) did not differ fro m the included patients. These patients were examined by an ophthalmologist only. Experimental protocolAfter the assessment of best corrected visual a c u i t y, each patient was screened for the p resence of diabetic retinopathy after dilation of pupils (tropicamide 1%) and subsequent slit-lamp biomicroscopy by an experienced ophthalmologist. During the study period, six senior ophthalmologists, not specializing in diabetic re t i n o p...

Nonmydriatic teleretinal imaging improves adherence to annual eye examinations in patients with diabetes

“…Adherence to guidelines for an annual eye exam in patients with DM ranges from 34 to 65 percent [3][4], suggesting an urgent need for alternative strategies for assessing level of DR. Several technologies that offer simple, low-cost, and convenient digital photographic techniques for assessing level of DR have been evaluated and compared with the ETDRS seven standard field images. Over a wide range of populations, the sensitivity and specificity of these various digital exam methods substantially agreed with the ETDRS classification for the grading of DR [5,[8][9][10][11][12][13][14][15]. This substantial agreement between digital imaging and ETDRS standards appears to be consistent across a wide variety of systems, technologies, number of photographic fields obtained, image format (e.g., color vs monochromatic), and type of fundus camera used to obtain the images.…”

“…Recent reports have highlighted the potential for digital retinal imaging to augment primary care treatment of patients at risk for DR [7][8][9][10][11]. Indeed, the operating characteristics of DR detection with teleretinal imaging compare with clinic-based ophthalmoscopy [5,[12][13][14][15].…”

Diabetic retinopathy

“…Since digital cameras are more sensitive than film, less light is necessary to obtain retinal images of sufficient quality for grading [67]. Further possibilities offered by digital imaging include stereo imaging [67] and telemedicine [68]. Algorithms for automated photographic reading could possibly reach acceptable sensitivity (78-88%) and specificity (84-100%) in detecting different lesions of retinopathy, as compared to an ophthalmologist [69,70], opening the way to computer-assisted grading.…”

Screening and prevention of diabetic blindness

“…The EU-funded project OPHTEL was initiated with the aim of developing telemedicine services within ophthalmology, especially diabetic retinopathy (www-ophtel.gsf.de). The project partners from Germany, Italy, England, and Denmark have successfully studied both clinical, logistic and technical parameters of relevance for transmitting fundus photographs obtained in a screening setting for diabetic retinopathy (Mann et al 1998;Williamson & Keating 1998;Liesenfeld et al 1999;. The software has presently been adapted to a setting named ''Dansk Teleoftalmologi'' based at the Department of Ophthalmology, Århus University Hospital, Denmark, offering free telemedicine services to all Danish ophthalmologists (www.teleoftalmologi.dk).…”