A comparison of digital nonmydriatic fundus imaging with standard 35-millimeter slides for diabetic retinopathy.

PURPOSE: The purpose of this study was to compare nonmydriatic digital images with 35-mm slide images for the detection of diabetic retinal findings.

STUDY DESIGN: Comparative, observational case series.

PARTICIPANTS: Twenty-two patients with diabetes.

METHODS: Diabetic patients underwent digital (nonmydriatic fundus camera attached to a digital back) and standard dilated 35-mm retinal photography of three areas: posterior pole, nasal retina, and temporal retina. The images were reviewed by a single masked grader for the presence or absence of specific retinal findings.

PRIMARY OUTCOME MEASURES: Presence or absence of neovascularization of the disc (NVD), neovascularization elsewhere (NVE), venous beading (VB), nerve fiber layer (NFL) hemorrhage, dot-blot hemorrhage, microaneurysm (MA), clinically significant macular edema, cotton wool spot, intraretinal microvascular anomaly (IRMA), hard exudate (HE), and retinal pigment epithelial (RPE) pigmentary changes.

RESULTS: Forty eyes of 22 patients underwent both imaging procedures. The agreement between image type was highest for IRMA (97.5%) and VB (95%) and lowest for RPE pigmentary changes (65%) and MA (62.5%). Sensitivity ranged from 25% (NVD) to 100% (VB). Specificity ranged from 90% (RPE pigmentary changes) to 100% (NVD, NVE, VB, NFL hemorrhage, HE). Positive predictive value ranged from 50% (IRMA) to 100% (NVD, NVE, HE, NFL, VB). Negative predictive value ranged from 48% (MA) to 100% (IRMA).

CONCLUSIONS: Nonmydriatic digital fundus imaging for detection of diabetic retionopathy has a low sensitivity rate and a high specificity rate and is less clinically useful than standard dilated 35-mm fundus slide images.