Digital Retinal Images and Teleophthalmology for Detecting and Grading Diabetic Retinopathy

Abstract

6OBJECTIVE -Detecting and grading of diabetic retinopathy (DR) by means of digital retinal images sent via the Internet.RESEARCH DESIGN AND METHODS -Four nonstereoscopic digital retinal images (45°field each) of 126 eye fundus images from 70 diabetic patients were obtained with a nonmydriatic camera at two peripheral units. The images were sent via the Internet using a web-based system to a reference center, where they were diagnosed and graded by one ophthalmologist. These results were compared with those obtained by two other ophthalmologists, one at each peripheral unit, after direct examination of the patients. A modified severity scale of Airlie House was used for grading DR in all cases. Agreement between observers was assessed using unweighted for categorical data and the intraclass correlation coefficient (ICC) for continuous data. RESULTS -Presence of DR was detected in 69 eyes (55%). All eyes with DR (69 of 69, 100%)were correctly identified ( ϭ 1) by inspecting the digital images. In 118 eyes (118 of 126, 94%), 57 with no DR and 61 with DR, there was an agreement between the gradation made after the direct examination and the gradation made after the inspection of the images (ICC ϭ 0.92). In eight eyes with DR (8 of 126, 6%), there was disagreement in the grading made with both techniques.CONCLUSIONS -Inspection of digital retinal images sent via the Internet allowed diagnosis and grading of DR. The presence or absence of DR was correctly assessed by inspection of the images in all instances. We also found agreement, in most cases, between retinopathy gradation made from the images and the gradation made by direct examination of the eyes. These findings suggest that this technique is suitable for screening procedures.

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.…”

“…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. Independent of the imaging system, the substantial agreement with the ETDRS classification appears to require that experienced graders interpret retinal images [12].…”

“…Indeed, the operating characteristics of DR detection with teleretinal imaging compare with clinic-based ophthalmoscopy [5,[12][13][14][15]. A potentially important role for teleretinal imaging is to serve as a remote DR assessment and triage tool for the numerous patients with DM who are at lower risk yet require ongoing eye care.…”

Nonmydriatic Fundus Photography for Teleophthalmology Diabetic Retinopathy Screening in Rural and Urban Clinics

“…Nonmydriatic fundus cameras allow for acquisition of highquality digital fundus images. 10,21 A single central 45°fundus image can be obtained without pharmacologic dilation by noncertified photographers with minimal training because the cameras have autofocusing capacity to image the disc and macula. In our study, the ease of use was evident by the high percentage of images that were of adequate quality (i.e., good or excellent) for interpretation from both rural and urban locations (82.4% and 85.7%, respectively).…”

“…9 An annual dilated eye exam is recommended for diabetic patients 1 ; however, ophthalmology services are not always readily or widely accessible in remote rural areas. 10 In urban areas where ophthalmology services are available, many patients (perhaps as many as 40-50% 11 ) are not screened annually because of nonadherence to recommended guidelines. [12][13][14] Teleophthalmology is therefore a cost-effective means for screening diabetic retinopathy 15 and in fact less expensive than conventional retinal examination.…”