Accuracy and Reliability of a Handheld, Nonmydriatic Fundus Camera for the Remote Detection of Optic Disc Edema

Background: Optic disc edema can be an important indicator of serious neurological disease, but is poorly detected using the direct ophthalmoscope. Portable fundus photography may overcome this difficulty. Introduction: The purpose of this study was to determine the sensitivity and specificity of a handheld, nonmydriatic fundus camera for the detection of optic disc edema. Materials and Methods: Retrospective review of nonmydriatic optic disc photographs taken with a portable fundus camera (Pictor Plus; Volk Optical, Mentor, OH) from the University of Michigan Neuro-Ophthalmology Clinics. We included 103 consecutive eyes with optic disc edema and 103 consecutive eyes without optic disc edema of 109 patients. Four masked neuro-ophthalmologists graded a single photograph of each optic disc presented in randomized order and documented the presence of optic disc edema. Sensitivity and specificity of graders' photographic interpretation was compared with clinical examinations. Reliability of assessments within and between graders was determined using kappa statistics. Results: The sensitivity and specificity for detection of optic disc edema were 71.8-92.2% and 81.6-95.2%, respectively. Photos were found to be ungradable in 0-8.3% of cases. The intergrader reliabilities ranged from 0.60 [95% confidence interval (CI): 0.52-0.67] to 0.72 (95% CI: 0.66-0.77). Intragrader reliability ranged from 0.76 (95% CI: 0.63-0.92) to 0.82 (95% CI: 0.69-0.95). Discussion: Photographs taken with portable, nonmydriatic technology met threshold sensitivity and specificity for remote screening for optic disc edema when performed by most, but not all graders. Reliability between graders was moderate-strong and strong within individual providers. Conclusions: Portable photography holds promise for use in remote screening of optic disc edema.