title: Comparison of peripheral refractions determined by different instruments.
abstract: OBJECTIVE
  To compare peripheral refractions obtained with a Hartmann-Shack sensor instrument and two commercial autorefractors.
  
  
  METHODS
  Measurements were taken with a laboratory Hartmann-Shack instrument, the Canon Autoref R-1, and the Shin-Nippon SRW-5000 to 40 degrees in both directions along the horizontal meridian.
  
  
  RESULTS
  The agreement between the Hartmann-Shack instrument and the Shin-Nippon autorefractor was good, with mean power differences varying from 0.3 D at the center of the visual field to 0.7 D at the edge of the visual field. The agreement between the Hartmann-Shack and Canon Autoref R-1 was not as good, but neither was the agreement between the Shin-Nippon and Canon instruments.
  
  
  CONCLUSIONS
  The agreement between the instruments was similar to other comparisons made between different techniques. Combined with the high magnitude of peripheral refractions, this indicates that the Hartmann-Shack sensor technique can validly be extended from measuring central refractions to measuring peripheral refractions.
mesh_terms: D006801:Humans; D008954:Models, Biological; D009907:Optometry / Q000295:instrumentation*; D012029:Refraction, Ocular; D014794:Visual Fields