title: Sensitivity and specificity of digital retinal images in grading diabetic retinopathy.
abstract: OBJECTIVE
  To assess three novel digital fundus cameras for diabetic retinopathy (DR) screening.
  
  
  METHODS
  Digital colour and red-free retinal imaging (Topcon TRC 50 IA, Canon CR6-45NM, and MediTell) was used to capture 427 images of 70 diabetes patients and control subjects. The images were graded for DR by three readers in a randomized and masked manner using a modified Early Treatment Diabetic Retinopathy Study classification. The reference standard was based on mydriatic ophthalmoscopy and colour and red-free images.
  
  
  RESULTS
  Digital 50 degrees red-free imaging had sensitivity of 97.7%, two-field 50 degrees colour imaging 94.0%, and two-field 45 degrees colour imaging sensitivity of 88.9%. The specificity of these imaging modalities was 98.9-100%, and ungradeable images represented 1.2-1.6%. The hand-held digital colour videocamera (MediTell) showed a sensitivity of 6.9% and ungradeable images represented 92.3%.
  
  
  CONCLUSIONS
  Digital 50 degrees red-free and two-field 50 degrees or 45 degrees colour imaging were suitable for DR screening, whereas the hand-held digital videocamera did not fulfil the needs of DR screening.
authors.affiliation: Laboratory of Computational Engineering, Helsinki University of Technology, Espoo, Finland.
authors.forename: Jukka M
authors.initials: JM
authors.lastname: Saari
authors.forename: Paula
authors.initials: P
authors.lastname: Summanen
authors.forename: Tero
authors.initials: T
authors.lastname: Kivelä
authors.forename: K Matti
authors.initials: KM
authors.lastname: Saari
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003922:Diabetes Mellitus, Type 1 / Q000150:complications; D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D003930:Diabetic Retinopathy / Q000145:classification* / Q000175:diagnosis*; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation*; D004311:Double-Blind Method; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010781:Photography / Q000295:instrumentation*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017216:Telemedicine