Purpose: 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.
Design: Comparison of techniques.
Setting: Clinic.
Patients: A total of 75 eyes of 48 adults.
Observation procedures: 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.
Main outcome measure: 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.
Conclusion: 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.