Comparison of frequency doubling perimetry and standard achromatic computerized perimetry in patients with glaucoma

Purpose: To evaluate the reproducibility and efficacy of frequency-doubling perimetry (FDP), a new perimetric method for the detection of functional g laucomatous damage. Methods: Thirty-four glaucomatous eyes of 34 patients w ere examined by FDP (using the complete N30 threshold test of the Humphrey Frequency Perimeter) and by standard achromatic computerized perimetry (SAC ; using the full threshold program 30-2 of the Humphrey Field Analyzer). Tw enty-six of these eyes were examined twice by FDP. Reproducibility of repea ted FDP was tested by the difference and the average of mean deviations (MD ). Efficacy was studied by comparison of FDP and SAC using MD, as well as t hreshold results of FDP and corresponding SAG-tested areas. Spearman's rank correlation was calculated. Results: A significant correlation of repeated FDP examinations was found regarding MD [r=0.94, P <0.00001 (n=26)]. The r eproducibility of FDP was independent of the glaucomatous damage [r=0.04, P =0.85 (n=26)], based on the correlation of the difference, and the average of MD. The MD of FDP and that of SAC showed a significant correlation [r-0. 87, P <0.00001 (n=34)]. In advanced glaucoma, FDP tended to yield lower mea surement values than SAG. Regarding corresponding areas, there was a signif icant correlation between threshold results of FDP-tested areas and the cor responding SAC testpoints [r=0.92, P <0.00001 (n=34)]. The conformity decre ased from the peripheral to the central tested visual field. Conclusions: S ufficient reproducibility of FDP could be demonstrated in early and advance d glaucomatous visual field defects. Conformity between FDP and SAC was sho wn in terms of MD and threshold results of FDP-tested areas and correspondi ng SAG testpoints.