Digital Retinal Images and Teleophthalmology for Detecting and Grading Diabetic Retinopathy
- Francisco Gómez-Ulla, MD1,
- Maria I. Fernandez, MD1,
- Francisco Gonzalez, MD12,
- Pablo Rey, PHD3,
- Marta Rodriguez, MD4,
- Maria J. Rodriguez-Cid, MD1,
- Felipe F. Casanueva, MD5,
- Maria A. Tome, MD5,
- Javier Garcia-Tobio, MD3 and
- Francisco Gude, MD6
- 1Ocular Diabetes and Medical Retina Unit, Division of Ophthalmology, Department of Surgery, School of Medicine, University of Santiago de Compostela and Complejo Hospitalario, Universitario de Santiago de Compostela, Santiago de Compostela, Spain
- 2Department of Physiology, School of Medicine, University of Santiago de Compostela and Complejo Hospitalario, Universitario de Santiago de Compostela, Santiago de Compostela, Spain
- 3Supercomputation Center of Galicia (CESGA), Santiago de Compostela, Spain
- 4Department of Ophthalmology, Hospital Meixoeiro, Vigo, Spain
- 5Division of Endocrinology, Department of Medicine, School of Medicine, University of Santiago de Compostela and Complejo Hospitalario, Universitario de Santiago de Compostela, Santiago de Compostela, Spain
- 6Clinical Epidemiology Unit, School of Medicine, University of Santiago de Compostela and Complejo Hospitalario, Universitario de Santiago de Compostela, Santiago de Compostela, Spain
OBJECTIVE—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 κ 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 (κ = 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 = 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.
- DR, diabetic retinopathy
- ETDRS, Early Treatment Diabetic Retinopathy Study
- HRC, high-risk characteristic
- ICC, intraclass correlation coefficient
- JPEG, Joint Photograph Experts Group
- NDR, non-DR
- NPDR, nonproliferative DR
- PDR, proliferative DR
Address correspondence and reprint requests to Francisco Gómez-Ulla, Department of Ophthalmology, Hospital Provincial de Conxo, C/Ramón Baltar s/n, E-15706, Santiago de Compostela, Spain. E-mail:or .
Received for publication 16 October 2001 and accepted in revised form 1 February 2002.
A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.
See accompanying editorial on p. 1477.
- DIABETES CARE