Clinical comparison of frequency doubling technology perimetry and Humphrey perimetry

Aim-To determine the number of missed points on frequency doubling technolo gy (FDT) perimetry that optimise the sensitivity and specificity of the tes t and to determine the topographical accuracy of the test in a clinical set ting. Methods-In a prospective study, the perimetric data from 99 patients who un derwent both FDT perimetry in the screening mode and Humphrey 24-2 (H24-2) were used to determine the sensitivity and specificity of the FDT perimetry compared with the full threshold H24-2 as the gold standard. Results-Missed points on the FDT perimetry correlated with both the mean de viation and the corrected pattern standard deviation on the Humphrey perime try. A score assigned to abnormal points on the FDT perimetry and the Humph rey total deviation plot showed a significant correlation for both the loca tion and the depth of the defect. In comparing the Humphrey hemifield test with the FDT perimetry results, if at least one missed point on the frequen cy doubling test was considered as abnormal then the overall sensitivity of the test was 78.1% and the specificity was 89.1%. Conclusion-FDT perimetry in the screening mode performed in a clinical sett ing was highly specific, exhibited reasonable sensitivity, and accurately d etermined the location and depth of scotomas when compared with the full th reshold Humphrey 24-2.