Use of real-time telemedicine in the detection of diabetic macular oedema: a pilot study.

PURPOSE: The high prevalence of diabetic retinopathy (21-36%) and 2 yearly reviews recommended by the National Health and Medical Research Council for diabetics with no retinopathy creates a considerable burden for review in rural and regional Australia. Screening for diabetic retinopathy using telemedicine has significant implications. If effective, such a tool would have an impact on finance and resource allocation. The purpose of the study was to establish if telemedicine could distinguish clinically significant macular oedema (CSME) from eyes free of this form of disease.

METHODS: A study population with representative examples of normal fundi and the different grades of retinopathy was chosen from existing records. The specificity and sensitivity of telemedicine diagnosis was compared with fundus photography and examination by an experienced ophthalmologist as a 'gold standard', in a blinded manner. Real-time telemedicine assessment was performed with live video and audio connections with the transmitting and receiving units set in different areas of the ophthalmology department. The transmission end consisted of a video camera mounted on a slit lamp and the receiving unit consisted of a 21'' LCD monitor. A video conference link was established using three ISDN lines capable of 128 kb per second transfer per line allowing for a total of 348 kb per second when utilizing all three lines for high resolution images. Fundus photographs were taken with a Zeiss FF 450 Plus Digital imaging system.

RESULTS: For telemedicine, sensitivity was 38% (95% CI, 35-40%) and specificity was 95% (95% CI, 91-99%). For photography, sensitivity was 75% (95% CI, 71-79%) and specificity was 95% (95% CI, 91-99%).

CONCLUSIONS: In this pilot study, sensitivity of detection of CSME by photography was considerably better than for live-link telemedicine. This study tends to confirm the continued superiority of examination of the patient by an experienced ophthalmologist as the best method of screening for CSME, a sight threatening form of diabetic retinopathy.