Quality assurance for diabetic retinopathy telescreening.

AIMS: TOSCA was an EU-Commission supported international research project designed to develop telescreening services in diabetic retinopathy and glaucoma. This paper describes the quality assurance methods developed for the diabetic retinopathy telescreening service within the TOSCA project. SETTING: The study was performed in 1895 patients with diabetes between 2000 and 2002 at diabetic retinopathy screening sites in five European countries. Data were analysed centrally. METHODS: Patients attending each clinic's diabetic retinopathy screening service received standardized retinal photography. The images and associated data were transferred electronically to a remote location for grading. Each photographer uploading images and each grader downloading images for assessment was controlled by a systematic quality management approach. The quality assurance measures defined were image quality, intragrader reliability. A cockpit chart was developed for the management and presentation of relevant results and quality measures. For the intragrader reliability tests, 10% of the images were processed for a second grading. An algorithm for calculating differences between repeated gradings was developed. RESULTS: The assessment of image quality for the different sites showed that only 0-0.7% were unassessable. One hundred per cent agreement for both gradings was achieved in 50-85% of graded cases, depending on site and grader, and an agreement better than 95% in 71-100% of cases. CONCLUSIONS: A telemedicine-supported quality assurance process is practical and advantageous. The cockpit charts have proven to be useful tools when monitoring the performance of a telescreening service. Grader feedback showed high satisfaction with the quality assurance process.

Feasibility of using the TOSCA telescreening procedures for diabetic retinopathy.

AIMS: The TOSCA project was set up to establish a tele-ophthalmology service to screen for diabetic retinopathy (DR) in Europe. The aim of this study was to determine the feasibility of establishing telemedicine-based digital screening for detecting DR and to evaluate the satisfaction of both patients and healthcare professionals with the screening procedures used within the TOSCA project. METHODS: The study was a non-randomized, multicentre study carried out in four different countries over a period of 3 months. Patients (n = 390) with diabetes aged > 12 years were included. Two digital retinal images per eye (macular and nasal) were taken and exported to a central server. Patients were asked to complete a questionnaire to assess satisfaction. Accredited graders carried out grading remotely and the results were reported back to the referring centre. Previously graded patient data chosen randomly to represent examples of both DR and no DR were also sent anonymously to the grading centre at a frequency of approximately every 10 patients. RESULTS: Most (99%) of the images were assessable enabling a retinopathy grade to be assigned to the patient. Patients found the retinal photography procedures acceptable; only 6% in one centre would not recommend the procedure. Healthcare professionals (photographers and graders) were also satisfied with the overall procedures. The average time taken to grade each patient was approximately 5 min. CONCLUSIONS: This study demonstrated that it is feasible to electronically transmit and grade retinal images remotely using the TOSCA process. Built-in quality assurance procedures proved acceptable.