Abstract

MUNOZ NEGRETE, FJ; REBOLLEDA, G; GONZALEZ MARTIN-MORO, J  and  CERIO RAMSDEN, CD. Frequency doubling perimetry in terminal visual field defects. Arch Soc Esp Oftalmol [online]. 2003, vol.78, n.4, pp.203-209. ISSN 0365-6691.

Purpose: To evaluate the Frequency Doubling Technology (FDT) in end-stage glaucomatous visual field defects. Methods: FDT (C-20 threshold test) was performed in 22 consecutive patients presenting an end-stage visual field defect with 24-2 SITA (0 dB in more than 75% and less than 100% of the visual field). Comparisons of the percentage of non-abolished points, topographic correlation, test duration and global indexes were performed between C-20 and 24-2 SITA test. Results: FDT sensitivity was 100%. C-20 test showed 13.7% more points with sensitivity greater than 0 dB compared to 24-2 test (P = 0.002). Two and a half less minutes were required for C-20 test performing (P < 0.001). The mean value of Mean Defect was 11.48 dB better in FDT (P = 0,000). The mean value of the Pattern Standard Deviation was 5.37 dB (SD: 1.92) and 6.35 dB (SD: 3.61) for 24-2 and C-20 test respectively (P = 0.258). The inferotemporal quadrant was the best conserved in both perimetric strategies (Kappa agreement test value = 0.911; P < 0.001). Conclusions: FDT showed greater ability than 24-2 test for end-stage visual field defects evaluation, with the advantage of being less time-consuming. Very good topographic correlation between both strategies was found. Further studies evaluating FDT reproducibility in severe glaucomatous visual field damage are necessary.

Keywords : Frequency doubling perimetry; FDT; advanced glaucoma; automated perimetry.