title: Comparison of retinal vessel measurements in digital vs film images.
abstract: OBJECTIVE
  To compare central retinal artery equivalents (CRAE) and central retinal vein equivalents (CRVE) from vessels measured from images captured with a digital camera and digitized images taken with a film camera.
  
  
  METHODS
  Comparison of techniques.
  
  
  METHODS
  
  
  
  METHODS
  Clinic.
  
  
  METHODS
  A total of 75 eyes of 48 adults.
  
  
  METHODS
  Gradings of retinal vessel diameters from images produced by using two photographic techniques: directly from a 45 degrees digital camera and digitized by scanning from a 30 degrees film-based camera.
  
  
  METHODS
  Differences in CRAE and CRVE from two types of images.
  
  
  RESULTS
  CRAE and CRVE were highly comparable between the two techniques with correlation coefficients of 0.88 and 0.87, respectively.
  
  
  CONCLUSIONS
  Estimates of CRAE and CRVE from measurements taken from digitally captured and digitized film-based images were highly comparable. It is likely that inferences about factors associated with retinal vessel diameters will be unbiased by the method of imaging.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin Medical School Madison, Madison, Wisconsin 53726, USA. mosher@epi.ophth.wisc.edu
authors.forename: Anne
authors.initials: A
authors.lastname: Mosher
authors.forename: Barbara E K
authors.initials: BE
authors.lastname: Klein
authors.forename: Ronald
authors.initials: R
authors.lastname: Klein
authors.forename: Michael D
authors.initials: MD
authors.lastname: Knudtson
authors.forename: Nicola J
authors.initials: NJ
authors.lastname: Ferrier
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001837:Body Weights and Measures; D006801:Humans; D008875:Middle Aged; D010781:Photography / Q000379:methods*; D012171:Retinal Vessels / Q000033:anatomy & histology*; D012815:Signal Processing, Computer-Assisted