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

OBJECTIVE - The importance of screening for diabetic retinopathy has been e stablished, but the best method for screening has not yet been determined. We report on a trial of assessment of digital photographs by telemedicine c ompared with standard retinal photographs of the same fields and clinical e xamination by ophthalmologists. RESEARCH DESIGN AND METHODS - A total of 129 diabetic inpatients were scree ned for diabetic retinopathy by slit-lamp biomicroscopy performed by an oph thalmologist and by two-field 50 degrees non-stereo digital fundus photogra phs assessed by six screening centers that received the images by electroni c mail. Conventional 35-mm transparencies of the same fields as the digital photographs were assessed by a retinal specialist and served as the refere nce method for detection of diabetic retinopathy. Slit-lamp biomicroscopy w as the reference method for the detection of macular edema. RESULTS - The prevalence of any form of diabetic retinopathy was 30% (n = 3 5), of sight-threatening retinopathy including macular edema, the prevalenc e was 6% (n = 7). The assessment of digital images by the six screening cen ters resulted in a median sensitivity of 85% and a median specificity of 90 % for the detection of moderate nonproliferative or sight-threatening diabe tic retinopathy. Clinically significant macular edema (n = 4) was correctly identified in 15 of the 24 grading reports. An additional seven reports re ferred the patients for further investigation because of concurrent diabeti c retinopathy. CONCLUSIONS - Telescreening for diabetic retinopathy by an assessment of tw o-field 50 degrees non-stereo digital images is a valid screening method. A lthough detection of clinically significant macular edema using biomicrosco py is superior to digital or standard non-stereo photographs, only few pati ents with sight-threatening diabetic retinopathy are missed.