The Role of Digital Fundus Photography in Diabetic Retinopathy Screening

Abstract

Purpose: The role of digital monochromatic nonmydriatic fundus photography as an adjunct in the diagnosis of diabetic retinopathy is evaluated. Methods: 197 patients were sequentially evaluated by three different techniques: dilated ophthalmoscopy by an experienced ophthalmologist, performance of 7 standard color mydriatic stereo fields, and a single digital monochromatic nonmydriatic image incorporating the disc and macula. Stereo color photographs served as the reference standard and were compared to either ophthalmoscopy performed by a physician, or a single digital photograph transmitted electronically to a reading site and evaluated by a trained non-physician grader. Sensitivity and specificity of the three methods were compared. The decision as to whether or not to refer to an ophthalmologist for potential treatment (Kaiser modified ETDRS level >21) was then chosen for analysis. Results: A single nonmydriatic monochromatic digital photograph appeared equivalent to standard color photography and more sensitive than mydriatic ophthalmoscopy in the detection of diabetic retinopathy in this patient population. Sensitivity of digital photography compared with color photography was 78%, and the specificity 86% constrasted with comparable ratios of 34% and 100% for ophthalmoscopy versus color photography. No patient identified by opthalmoscopy alone for referral based on retinopathy level of >21 would have been missed by a single digital monochromatic photographic image. Conclusion: A single nonmydriatic monochromatic wide field digital photograph of the disc and macula in diabetic patients is a sensitive and cost-effective means for detecting diabetic retinopathy in high-risk populations.