Comparison among methods of retinopathy assessment (CAMRA) study: Smartphone, nonmydriatic, and mydriatic photography

Purpose We compared smartphone fundus photography, nonmydriatic fundus photography, and 7-field mydriatic fundus photography for their abilities to detect and grade diabetic retinopathy (DR). Design This was a prospective, comparative study of 3 photography modalities. Participants Diabetic patients (n = 300) were recruited at the ophthalmology clinic of a tertiary diabetes care center in Chennai, India. Methods Patients underwent photography by all 3 modalities, and photographs were evaluated by 2 retina specialists. Main Outcome Measures The sensitivity and specificity in the detection of DR for both smartphone and nonmydriatic photography were determined by comparison with the standard method, 7-field mydriatic fundus photography. Results The sensitivity and specificity of smartphone fundus photography, compared with 7-field mydriatic fundus photography, for the detection of any DR were 50% (95% confidence interval [CI], 43-56) and 94% (95% CI, 92-97), respectively, and of nonmydriatic fundus photography were 81% (95% CI, 75-86) and 94% (95% CI, 92-96%), respectively. The sensitivity and specificity of smartphone fundus photography for the detection of vision-threatening DR were 59% (95% CI, 46-72) and 100% (95% CI, 99-100), respectively, and of nonmydriatic fundus photography were 54% (95% CI, 40-67) and 99% (95% CI, 98-100), respectively. Conclusions Smartphone and nonmydriatic fundus photography are each able to detect DR and sight-threatening disease. However, the nonmydriatic camera is more sensitive at detecting DR than the smartphone. At this time, the benefits of the smartphone (connectivity, portability, and reduced cost) are not offset by the lack of sufficient sensitivity for detection of DR in most clinical circumstances.