Learning effect, normal range, and test-retest variability of Frequency Doubling Perimetry as a function of age, perimetric experience, and the presence or absence of glaucoma

The learning effect for several different Frequency Doubling Perimetry parameters was studied in full threshold mode in a large group of patients (n = 342) of various ages, with and without perimetric experience, and with and without glaucoma. A significant learning effect was only found for the mean deviation (MD) in aged normals without perimetric experience. The median of MD increased for both OD (from +0.2 to +1.0 dB) and for OS (from +0.5 to +11.3 dB). The effect disappeared largely during a third visit (median OD +1.2 dB, OS +11.3 dB). The normal range and the test-retest variability were measured in the same dataset. The learning effect for MD (1 dB or less) appeared to be small as compared with both the normal range (about 12 dB) and the test-retest variability (about 3 dB).