[1]Telemedicine Unit University of Concepción Concepción 4070386 Chile;
[2]School of Medicine University of Concepción Concepción 4070386 Chile;
[3]University of Oxford University of Gloucestershire Oxford OX1 2JD England UK;
ophthalmology; teleophthalmology; diabetes mellitus; diabetic retinopathy; telemedicine;