Abstract
Purpose: :
To determine the reproducibility of the second generation perimetry with Frequency Doubling Technology (FDT2–Matrix) in patients with a range of severity of glaucoma.
Methods: :
50 stable glaucoma subjects underwent visual field testing with the FDT2–Matrix 24–2 threshold strategy on 5 different days in a 2 months period. The same FDT2–Matrix unit was used by the same operator for all measurements. Intraclass correlation coefficient (ICC), coefficient of variation (COV), and Standard Deviation (SD) were calculated for the Mean Deviation (MD) and Pattern Standard Deviations (PSD) global indices, as well as for every location in the threshold plot.
Results: :
ICCs were 0.976 and 0.944 for MD and PSD respectively. By location, ICCs ranged from 0.728 (corresponding to a location beside the blind spot) to 0.942 (corresponding to a location in the supero–nasal quadrant). COVs were, on average, 10.4% and 8.6% for MD and PSD respectively. COVs by location ranged from 9.3% (corresponding to the foveal threshold) to 31.9% (corresponding to a location in the infero–nasal quadrant, just below the horizontal meridian). SDs were, on average, 0.888 dB and 0.446 dB for MD and PSD respectively. By location, SDs ranged from 1.716 dB (corresponding to the location of the best ICC (i.e. in the supero–nasal quadrant)) to 3.197 dB (corresponding to the location of the worst ICC (i.e. beside the blind spot)).
Conclusions: :
The FDT2–Matrix 24–2 threshold strategy has a good reproducibility. Even though this could suggest that FDT2–Matrix may provide useful information in the follow–up of glaucoma patients, further research are needed to understand the underlying mechanism that renders its good reproducibility.
Keywords: perimetry • visual fields • clinical (human) or epidemiologic studies: systems/equipment/techniques