Purpose:
Established recommendations for the prevention of diabetic retinopathy (DR) in the United States emphasize the importance of early detection and treatment. Reports in the literature focused on the role of non-mydriatic fundus camera in the screening process. However no one has yet to establish the best screening model. We evaluated the efficacy of the non-mydriatic fundus camera as a referral tool for DR, in a safety net institution.
Methods:
A non comparative, population based, cross sectional study between 6/2009 and 9/2011. Diabetic patients from Denver County were sent for DR screening performed within a primary care setting. A single field color image digital fundus camera (Topcon TRC NW-6S) was used to detect any retinal findings in a 45 degree filed of the posterior pole. All photographs were sent to a reading center at Denver Health Medical Center and interpreted by a group of retina specialists with in a week. Patients with retinal findings or unreadable photos were referred for a complete examination in the retina clinic.
Results:
950 diabetic patients were sent for fundus camera screening by their primary care providers, with an attendance rate of 65.7%. Overall photo quality rating was relatively high, 80.5% of them graded as good or fair. 19 photos (3.3 %) were considered to be completely unreadable. The prevalence of DR in our study population was 15.6%. 11 out of 57 patients with photographic DR findings, that attended the retina clinic, failed to have DR on a mydriatic fundus examination (a false positive rate of 19.3%). All other patients had mild to moderate NPDR (52.6%), severe NPDR (10.5%), PDR (17.4%) and CSME (28.1%). A false negative rate of 4.3% was found, with 19 patients known to have DR prior to screening. Risk factors independently associated with the presence of DR were male sex, race, DM type I, Insulin treatment, Hb A1c level, hypertension, atherosclerotic diseases and diabetes complications.
Conclusions:
A non-mydriatic fundus camera is an accurate and sensitive modality for an annual DR screening. It can be easily and effectively implemented into a community health practice, substantially lowering medical costs and providing an improved quality of care for diabetic patients.
Keywords: diabetic retinopathy • clinical (human) or epidemiologic studies: systems/equipment/techniques • imaging/image analysis: clinical