Diagnostic accuracy of handheld fundus photography: A comparative study of three commercially available cameras

Abstract

The objective of this study was to compare the sensitivity and specificity of handheld fundus cameras in detecting diabetic retinopathy (DR), diabetic macular edema (DME), and macular degeneration. Participants in the study, conducted at Maharaj Nakorn Hospital in Northern Thailand between September 2018 and May 2019, underwent an ophthalmologist examination as well as mydriatic fundus photography with three handheld fundus cameras (iNview, Peek Retina, Pictor Plus). Photographs were graded and adjudicated by masked ophthalmologists. Outcome measures included the sensitivity and specificity of each fundus camera for detecting DR, DME, and macular degeneration, relative to ophthalmologist examination. Fundus photographs of 355 eyes from 185 participants were captured with each of the three retinal cameras. Of the 355 eyes, 102 had DR, 71 had DME, and 89 had macular degeneration on ophthalmologist examination. The Pictor Plus was the most sensitive camera for each of the diseases (73–77%) and also achieved relatively high specificity (77–91%). The Peek Retina was the most specific (96–99%), although in part due to its low sensitivity (6–18%). The iNview had slightly lower estimates of sensitivity (55–72%) and specificity (86–90%) compared to the Pictor Plus. These findings demonstrated that the handheld cameras achieved high specificity but variable sensitivities in detecting DR, DME, and macular degeneration. The Pictor Plus, iNview, and Peek Retina would have distinct advantages and disadvantages when applied for utilization in tele-ophthalmology retinal screening programs. Author summary Telemedicine holds much promise to improve health care. One potential implementation of telemedicine is the use of remote diagnostics for screening. A diagnostic test could be performed in the community, or in a primary care clinic, and abnormal test results could trigger referral to the relevant provider. Eye diseases are well-suited to telemedicine approaches given the availability of portable imaging devices. For example, a number of handheld retinal cameras have been developed that could be used to screen for eye diseases like diabetic retinopathy and age-related macular degeneration. However, very few studies have compared different devices to assess their suitability for screening purposes. In this study we compared three portable, handheld retinal cameras. A group of ophthalmologists graded the images for diabetic retinopathy and macular degeneration. The photo-grades were compared with the in-person clinical exam done by another ophthalmologist. We found that one of the cameras, the Pictor Plus, had the best balance of detecting most of the true positive cases while minimizing the number of false positive cases. Although technologies may change, this study provides useful benchmarks to judge the accuracy of handheld retinal cameras.