Purpose
To describe the prevalence and treatment trends of diabetic retinopathy (DR) in a safety net population in Santa Clara County, CA, based on non-mydriatic fundus photography screening, and to determine their association with patient demographic and clinical factors.
Methods
A cross-sectional study was conducted on 8198 patients aged 25 to 84 with diabetes, who presented to Santa Clara Valley Medical Center for non-mydriatic fundus photography screening for DR between 2008 and 2012. Patients were graded on the presence and severity of DR. Prevalence of DR was calculated. Differences in the prevalence and treatment of DR based on race, age, sex, insurance status, whether the patient had a primary care provider (PCP) or diabetes care manager (DCM), duration of diabetes, HgbA1c, body-mass index, and treatment with insulin or oral agents, were tested by generalized linear model (GLM) Chi-square. GLM regression was performed to determine the odds ratio (OR) and 95% confidence intervals (CI) for DR and laser photocoagulation or vitreoretinal surgery for DR, in association with putative risk factors.
Results
In our population, the prevalence of any DR was 28.2%, with clinically significant DR present in 4.3% of patients. Significant independent predictors of clinically significant DR were longer duration of diabetes (OR 1.03, p=0.005), higher HgbA1c (OR 1.22, p=0.001), Hispanic race (OR 1.70, p=0.04), and having a primary care provider or diabetes care manager (OR 0.63, p=0.02). Significant predictors of laser or surgical treatment for DR included significant retinopathy seen on retinal photography (OR 21.6, p<0.001), longer duration of diabetes (OR 1.01, p=0.01), and higher HgbA1c (OR 1.35, p=0.001). Having a PCP/DCM was significantly associated (OR 1.20, p=0.02) with timely focal laser photocoagulation.
Conclusions
Our study provides data on the prevalence of diabetic retinopathy in a large safety net population residing in Santa Clara County, CA. Longer duration of diabetes, higher HgbA1c, and Hispanic race were significant predictors of retinopathy. Having a primary care provider or diabetes care manager was a significant negative predictor for clinically significant DR and a significant positive predictor for timely laser photocoagulation, suggesting the importance of the medical home in diabetes management, retinal screening and timely referral to ophthalmic care.