Portable point-of-care screening may help improve diabetic retinopathy diagnosis

An Australian study found that 39.6% of patients at high-risk diabetes clinics had diabetic retinopathy and 15.8% had vision-threatening diabetic retinopathy, previously undiagnosed in 59.3% and 62.8%, respectively.

Point-of-care screening for diabetic retinopathy may help improve diagnosis in high-risk patients, a recent study found.

Researchers in Australia performed a cross-sectional study of patients with diabetes attending foot ulcer or diabetes clinics at two hospitals. The goal of the study was to determine the prevalence of diabetic retinopathy and the diagnostic utility of screening this high-risk population at the point of care. Portable two-field, nonmydriatic fundus photography and combined electroretinogram/pupillometry (ERG) were used to assess diabetic retinopathy. Mydriatic photography was the reference standard. The results were published Aug. 2 by BMJ Open Diabetes Research & Care.

Two hundred seventy-three patients were included in the study. Of these, 39.6% were found to have any diabetic retinopathy and 15.8% had vision-threatening diabetic retinopathy (VTDR). A total of 59.3% of those with diabetic retinopathy and 62.8% of those with VTDR were previously undiagnosed. Nonmydriatic photography had a sensitivity of 20.2% and a specificity of 99.5% for any diabetic retinopathy, with a screening failure rate of 56.7%, while ERG had a sensitivity of 72.5% and a specificity of 70.1%, with a screening failure rate of 15.0%. Mydriatic photography yielded high-quality images with a screening failure rate of 7.6%. In multivariate logistic regression analysis, an estimated glomerular filtration rate of 29 mL/min/1.73 m2 or lower, an HbA1c level of 7.0% or higher, a pupil size below 4 mm in diameter, diabetes duration of five to 24 years, and a score of 22 or higher on ERG were strong predictors of diabetic retinopathy.

The authors noted that their study may have underreported diabetic retinopathy and may be subject to sampling bias, among other limitations. They concluded that prevalence of diabetic retinopathy and VTDR was high in patients attending high-risk diabetes clinics and that more than half of those affected were undiagnosed.

“This reinforces the dire need for improved screening services, tailored for high-risk populations. It also indicates the potential for tertiary point-of-care screening to enhance DR detection,” the authors wrote. “In this population, portable, non-mydriatic fundus photography had a high screening failure rate and low sensitivity. Similarly, ERG had a poor screening failure rate, as well as insufficient sensitivity and specificity. However, portable mydriatic retinal photography demonstrates promise in teleophthalmology services, with quick examinations and satisfactory diagnostic accuracy, substantially improving screening access for high-risk populations.”