Abstract
Abstract: :
Purpose: To determine to prevalence and characteristics of diabetic retinopathy in an urban diabetic population using a novel single-field digital monochromatic nonmydriatic photographic screening modality. Design: Prospective observational case series of 403 subjects from a large urban health maintenance organization in Oakland, California. Eligible patients included both type I and type II diabetic patients with any disease duration. Methods: All patients were evaluated by single-field digital monochromatic nonmydriatic photography incorporating the disc and macula. Digital photographs were transmitted electronically to a reading site and graded by an experienced non-physician grader according to the ETDRS diabetic retinopathy scale. Multivariate regression analysis was performed on the demographics data. Results: Signs of diabetic retinopathy were found in 240 participants (59.6%). When broken down by retinopathy severity, 40.4% had no retinopathy, 17.4% had microaneurysms only, 24.1% had mild nonproliferative diabetic retinopathy, 6.7% had moderate to severe nonproliferative diabetic retinopathy, 1.0% had proliferative diabetic retinopathy, and 10.4% had ungradeable images. Regression analysis revealed no association between age, gender, or ethnicity to the severity of retinopathy. Older age and any known cataract history were associated with increased incidence of ungradeable images. Conclusion: The single nonmydriatic monochromatic wide-field digital photographic screening modality found similar prevalence rates for diabetic retinopathy in this urban population compared to a number of well-defined populations in the literature. The elderly and those with any known cataract history are more likely to have ungradeable nonmydriatic digital photographs, and may benefit from traditional dilated screening examination. Our group previously demonstrated the relative equivalence of single-field nonmydriatic digital photography to stereo color photography in the screening of diabetic retinopathy. These findings further support potential role of such a screening modality, and offers insight into means of minimizing ungradeable images in such a screening program.
Keywords: 388 diabetic retinopathy • 430 imaging/image analysis: clinical • 354 clinical (human) or epidemiologic studies: prevalence/incidence