The potential of digital monochrome images versus colour slides in telescreening for diabetic retinopathy

Abstract

Summary We explored the potential of digital monochrome images as an alternative to colour slides in screening for diabetic retinopathy. Twenty-eight patients with diabetes were recruited for the study and 20 actually participated. Using a fundus camera (Nikon 505AF) one set of three digital images and one set of three colour slides were taken per eye. Two independent ophthalmologists graded the colour slides and the digital images for diabetic retinopathy. The ophthalmologists spent about two minutes grading each set of images, suggesting that specialists could potentially screen a large number of patients. The agreement between the two screening methods was 0.95 and 0.89, with respect to disease or no disease. The agreement ( κ) between the two ophthalmologists for grade of retinopathy was 0.47 when colour slides were employed and 0.61 when digital monochrome images were employed. The results indicate that digital red-free monochrome images represent a superior screening tool for diabetic retinopathy. Tele-screening may be beneficial when patients have to travel substantial distances to visit an ophthalmologist.