Table 3.

Peak velocity (mean and standard deviation) in phenylketonuria patients and in controls

Study participants	Horizontal saccades	Vertical saccades
PKU all (n = 19)	352.11/s (SD 33.48)	311.15 °/s (SD 36.67)
Phenylalanine concentrations within age-related therapeutic ranges (n = 9)	353.61°/s (SD 24.42)	316.02°/s (SD 42.60)
Phenylalanine concentrations above age-related therapeutic ranges (*) (n = 10)	350.77°/s (SD 39.57)	306.77 °/s (SD 33.25)
Controls (n = 99)	339.80 °/s (SD 42.32)	300.38 °/s (SD 43.28)

(*): 238.4 μmol/l (64%) higher in comparison to the maximal age adjusted reference