Research results from a systematic review of telemedicine studies, published in the British Journal of Ophthalmology, have shown a high rate of diagnostic accuracy for diagnosis of diabetic retinopathy (DR) via telemedicine. The systematic review and meta-analysis showed that telemedicine based on a digital imaging technique that combines mydriasis with a wide-angle field (100–200°) is the optimal choice in detecting the absence of DR and the presence of mild non-proliferative diabetic retinopathy (NPDR). Wide-spread use of internet communication and digital imagery has driven the potential for this health management tool allowing clinicians to detect DR in a non-ophthalmological setting benefitting patients in rural, remote or hard to reach locations.
The research, based at Nantong University, Jiangsu Province, China, set out to determine the diagnostic accuracy of telemedical applications to the management of diabetic retinopathy and diabetic macular oedema (DME). The researchers systematically reviewed 720 publications covering 1,960 participants, eventually performing a detailed analysis on 20 publications that met specific criteria including (1) the inclusion of subjects with either type 1 or type 2 diabetes; (2) inclusion of a direct comparison of telemedicine with 7F-ETDRS for DR or DME detection; and (3) included sufficient information to verify the diagnostic accuracy of the techniques used in individual studies. Although the gold standard for DR detection is the Early Treatment Diabetic Retinopathy Study (ETDRS) using 30°, seven standard field stereoscopic 35 mm colour slides (7F-ETDRS) or fundus fluorescein angiography (FFA), the techniques involved are time-consuming, expensive and often have poor compliance, consequently becoming impractical for routine clinical use. Alternatively, telemedicine, based on digital photographs of the fundus captured and forwarded electronically to an ophthalmologist is being used with increasing frequency to detect DR, especially for DR screening of remote and rural populations.
Results of the analysis showed that pooled sensitivity of telemedicine exceeded 80% in detecting the absence of DR, and exceeded 70% in detecting mild or moderate non-proliferative diabetic retinopathy (NPDR), DME and clinically significant macular oedema (CSME). Sensitivity in detecting severe NPDR was reported to be 53% (95% CI 45% to 62%). In addition, diagnostic accuracy was higher with digital images obtained through mydriasis (than through non-mydriasis), and was highest in detecting the absence of DR and the presence of mild NPDR when a wide angle (100–200°) was used compared with a narrower angle (45–60°, 30° or 35°). While the acceptance of wide-spread use of telemedicine will always be limited by the experience of the ophthalmologist reading and grading the digital images and the expertise of the technician who takes the original images, the authors of the study conclude that, “the high sensitivity of its detection of any clinical level of DR indicates that telemedicine can be used widely for DR screening”.