Effect of the Administration of Alpha-Lipoic Acid on Contrast Sensitivity in Patients with Type 1 and Type 2 Diabetes

Table 2

Characteristics of contrast sensitivity examinations in T1DM patients with and without ALA supplementation at baseline and after 3 months.

Spatial frequencies	T1DM patients without; ALA supplementation; CS × LC = 48 measurements			T1DM patients with; ALA supplementation; CS × LC = 40 measurements
	Baseline	After 3 months	𝑃 value	Baseline	After 3 months	𝑃 value
A-1.5 cpd
Mean. ± SD	6.5±1.5	6.0±1.6		5.6±1.1	5.6±1.2
Range	3.0–9.0	3.0–9.0	𝑃=0.009^∗∗	4.0–8.0	3.0–8.0	𝑃=0.614
Median	7.0	6.0		5.0	5.0
95% CI	[6.1; 7.0]	[5.5; 6.4]		[5.3; 6.0]	[5.2; 5.9]
B-3 cpd
Mean. ± SD	6.0±1.4	5.5±1.6		5.1±1.7	5.0±1.6
Range	2.0–8.0	1.0–9.0	𝑃=0.010^∗∗	2.0–8.0	1.0–9.0	𝑃=0.770
Median	6.0	6.0		5.0	5.0
95% CI	[5.6; 6.5]	[5.1; 6.0]		[4.5; 5.6]	[4.5; 5.5]
C-6 cpd
Mean. ± SD	5.3±2.2	4.8±2.0		4.2±2.2	4.2±2.2
Range	0.0–8.0	0.0–8.0	𝑃=0.005^∗∗	0.0–8.0	0.0–8.0	𝑃=0.947
Median	6.0	5.0		4.0	4.0
95% CI	[4.6; 5.9]	[4.2; 5.3]		[3.5; 4.9]	[3.5; 4.9]
D-12 cpd
Mean. ± SD	3.6±2.6	3.1±2.4		2.9±2.3	2.7±2.3
Range	0.0–8.0	0.0–8.0	𝑃=0.020^∗∗	0.0–7.0	0.0–7.0	𝑃=0.626
Median	4.0	4.0		3.0	2.0
95% CI	[2.8; 4.4]	[2.4; 3.8]		[2.1; 3.6]	[2.0; 3.5]
E-18 cpd
Mean. ± SD	2.1±2.2	2.0±2.0		1.7±1.9	1.5±1.9
Range	0.0–7.0	0.0–5.0	𝑃=0.530	0.0–5.0	0.0–6.0	𝑃=0.365
Median	1.0	1.5		0.5	0.0
95% CI	[1.4; 2.7]	[1.4; 2.5]		[1.1; 2.3]	[0.8; 2.1]

CS × LC: the number of contrast sensitivity measurements of each eye in 4 luminance conditions and under 5 spatial frequencies.
A-1.5, B-3, C-6, D-12, and E-18 cpd: spatial frequencies.
**Statistically significant differences between the baseline examination of T1DM patients without ALA supplementation versus after 3 months.