Table 5.

Comparison Between ST and PRO Filters for the ST_low and ST_high Sub-Groups. Mean ± SD of LogCS_ST and LogCS_PRO at Each Spatial Frequency and for the Area for Both Filters, Together with the Percentual Difference ε Between the Mean Values for the Two Filters, and the p-values Obtained by Paired Student’s t-Test, Calculated on the ST_low and ST_high Sub-Groups of the Whole Sample of Subjects or, in Brackets, Calculated on the ST_low and ST_high Sub-Groups of the Sample of PAL Subjects (Statistical Significance Set at P<0.01 at Each Spatial Frequency with Bonferroni Correction and at P<0.05 for the Area )

	LogCSST	LogCSPRO	ε (%)	p-value
STlow sub-group (LogCSST < LogCSthreshold)
1.5 cpd	1.62 ± 0.11 (1,62 ± 0.11)	1.67 ± 0.12 (1.67 ± 0.13)	+3.1% (+3.1%)	0.079 (0.217)
3.0 cpd	1.81 ± 0.07 (1.76 ± 0.07)	1.87 ± 0.11 (1.83 ± 0.09)	+3.3% (+4.0%)	0.009 (0.164)
6.0 cpd	1.87 ± 0.10 (1.85 ± 0.11)	1.89 ± 0.10 (1.87 ± 0.07)	+1.1% (+1.1%)	0.255 (0.509)
12.0 cpd	1.34 ± n.a.# (1.34 ± n.a.#)	1.34 ± 0.12 (1.34 ± 0.12)	0% (0%)	0.940 (0.940)
18.0 cpd	0.93 ± 0.19 (0.93 ± 0.20)	01± 0.22 (1.00 ± 0.23)	+8.6% (+7.5%)	0.236 (0.351)
	24.4 ± 1.1 (24.6±1.4)	25.0 ± 1.9 (25.2 ± 1.9)	+2.5% (+2.5%)	0.399 (0.382)
SThigh sub-group (LogCSST > LogCSthreshold)
1.5 cpd	1.92 ± 0.08 (1.85 ± n.a.#)	1.90 ± 0.12 (1.78 ± 0.09)	−1.0% (−3.8%)	0.432 (0.182)
3.0 cpd	2.11 ± 0.07 (2.06 ± n.a.#)	2.02 ± 0.10 (1.95 ± 0.09)	−3.1% (−3.1%)	0.005 (0.184)
6.0 cpd	2.15 ± 0.07 (2.11 ± n.a.#)	2.11 ± 0.13 (2.01 ± 0.09)	−1.9% (−4.7%)	0.197 (0.070)
12.0 cpd	1.78 ± 0.19 (1.66 ± 0.16)	1.72 ± 0.23 (1.59 ± 0.19)	−3.4% (−4.2%)	0.037 (0.151)
18.0 cpd	1.50 ± 0.16 (1.46 ± 0.13)	1.40 ± 0.21 (1.30 ± 0.22)	−6.7% (−11.0%)	0.005 (0.031)
	30.3 ± 2.3 (29.1 ± 1.7)	29.5 ± 2.7 (27.8 ± 2.1)	−2.4% (−4.4%)	0.012 (0.021)

Notes: ^#SD is not available (n.a.) because all data in the sub-group are equal. Bold character: statistically significant difference between LogCS_ST and LogCS_SRO.