Comparison Among Methods of Retinopathy Assessment (CAMRA) Study

Abstract

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.

The Diabetic Retinopathy Screening Workflow

“…Bland-Altman analysis demonstrated an average difference Although diabetic macular edema, for example, can be imaged using this technique (right), it has been reported that insufficient sensitivity is achieved when the technique is integrated into the screening workflow. 34 Left and center panel reproduced with permission from Bastawrous 33 ; right panel reproduced with permission from Ryan et al 34 of -.02 with 95% limits of agreement between -.21 and .16 for vertical cup-to-disc ratio assessment, suggesting good agreement between the lay-operated Peek Retina and the reference standard. 43 Peek Retina preproduction prototypes, shown in Figure 5, are presently being trialled alongside standard digital retinal cameras (Topcon NRW6, Topcon Corp, Tokyo, Japan) in an 18-site DR screening implementation and evaluation in Moshi, Tanzania.…”

“…34 The authors found the sensitivity of the smartphone images to be 81% and 50% compared to each standard respectively and the specificity to be 94% against each standard. They therefore concluded that 20D lens-assisted smartphone photography lacks sufficient sensitivity for detection of DR.…”

Technology in the management of diabetes mellitus

“…However, the non-mydriatic camera was more sensitive at detecting DR than the smartphone. [35] diabEtEs ElEctronic MEdical rEcords Diabetes is a chronic disease requiring lifelong follow-up and monitoring. Unfortunately, levels of glycaemic control have been found to be poor even among patients attending specialised diabetes clinics.…”

New Frontiers in Retinal Imaging

“…More straightforward operation of fundus cameras was further improved due to the development of nonydriatic imaging and near-infrared focusing, which increased reproducibility. For example, the Nidek Model AFC-230 (Nidek Inc., Fremont, CA), a nonmydriatic fundus camera with a 45-degree field view, has been demonstrated to be an efficient screening tool for diabetic retinopathy in a clinical trial [11] .…”