Table 3.

Basic PVEP parameters in the study and control groups

PVEP	Study group									Control group
	ampl P100 ampl P100 1°, µV		ampl P100 15', µV		lat P100 1°, ms		lat P100 15', ms		ampl P100 1°, µV		ampl P100 15', µV		lat P100 1°, ms		lat P100 15', ms
	median	SEM	median	SEM	median	SEM	median	SEM	median	SEM	median	SEM	median	SEM	median	SEM
At baseline	8.38	0.77	9.64	1.33	105	1.3	117.5	1.71	7.7	0.84	11	1.29	104.5	1.11	113.5	2.64
At 12 months	8.27	0.81	9.87	1.21	105	1.18	114		1.54	9.82	0.86	9.92	1.2	105	1.13	112.55	1.98
p value	0.73		0.3		0.95			0.71		0.2		0.97		0.11		0.96

Wilcoxon matched pairs test was used for statistical analysis. PVEP, pattern visual-evoked potentials; ampl, amplitude; lat, latency; med, median.