The automated perimeter is becoming the instrument of choice in the analysis of the visual field. There are a number of different perimeters in use and it can be difficult to compare results from two different instruments. This study did a statistical comparison of field test results from the Dicon TKS 4000 Automated Perimeter (program #9) and the Allergan Humphrey Field Analyzer or HFA (30-2 threshold using FastPac ). Central 30 degree, 76 point full threshold fields were performed on 20 optometry students using both instruments. Thresholds of grouped points were compared between instruments. A difference between instruments significant at P < 0.0001 for 19 of 24 groups was found. In addition, the HFA threshold values were consistently higher (average 2.47 dB difference) than the Dicon values. Each subject was tested twice on each instrument; both showed high test-retest correlations, 0.970 for the HFA and 0.971 for the Dicon. Test administration times were comparable (average 435.2 seconds for the HFA versus 430.2 seconds for the Dicon), although the Dicon averaged 41.5 fewer points tested per exam. Dicon' s kinetic fixation point produced higher numbers of fixation losses and false positive responses. The Dicon TKS 4000 was subjectively preferred over the Humphrey Field Analyzer by most subjects.
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