Table 4.

Mean contrast sensitivity (Log Units) of the ETPKU and control groups. Tests are two-tailed, using Mann Whitney U test. Values are shown as mean ± SD.

Spatial frequency (cycles/degree)	ETPKU	CONTROL	p-value
1.5	1.69 ± 0.19	1.90 ± 0.16	<0.001
3	1.94 ± 0.09	1.97 ± 0.13	<0.400
6	2.02 ± 0.17	2.09 ± 0.82	<0.013
12	1.72 ± 0.27	1.93 ± 0.12	<0.001
18	1.36 ± 0.24	1.53 ± 0.17	<0.003