Table 1.

The variation of the ultrasound parameters at days 0, 40, and 60 of topical vitamin C-based therapy, according to the three studied age intervals

Age interval	Parameter	0 days	P-value 0–40 days	40 days	P-value 40–60 days	60 days	P-value 0–60 days
20–35	Epidermis	0.142±0.030	0.54	0.136±0.021	0.005	0.164±0.025	0.049
	Dermis	1.40±0.171	0.6	1.383±0.143	0.72	1.399±0.145	0.91
	LEP	14,319±2,424	0.001	11,723±2,226	0.001	8,447±1,811	0.0001
	MEP	3,691±1,202	0.07	4,266±782	0.003	5,317±746	0.002
	HEP	976±523	0.006	1,629±688	0.0002	3,196±1,089	<0.0001
	LEPs	4,480±1,256	0.048	3,628±1,010	0.001	2,526±707	0.001
	LEPi	9,671±1,830	0.001	7,430±2,113	0.09	6,272±1,736	0.04
	LEPs/LEPi	0.465±0.10	0.29	0.520±0.202	0.1	0.423±0.14	0.36
35–50	Epidermis	0.137±0.02	0.2	0.144±0.023	0.25	0.154±0.029	0.4
	Dermis	1.352±0.136	0.69	1.340±0.106	0.59	1.352±0.083	0.98
	LEP	12,749±3,048	0.002	11,097±2,628	0.0001	8,616±2,753	0.0001
	MEP	4,319±950	0.28	4,557±1,071	0.06	5,078±1,368	0.044
	HEP	1,021±451	0.05	1,510±1,008	0.01	2,248±1,580	0.01
	LEPs	4,542±1,754	0.5	4,336±1,079	0.01	3,753±1,176	0.09
	LEPi	7,575±1,498	0.04	6,976±1,331	0.2	6,435±1,958	0.06
	LEPs/LEPi	0.592±0.16	0.5	0.619±0.07	0.35	0.591±0.11	0.98
>50	Epidermis	0.139±0.021	0.3	0.148±0.017	0.22	0.157±0.031	0.2
	Dermis	1.364±0.135	0.98	1.365±0.17	0.08	1.420±0.173	0.25
	LEP	12,453±2,713	0.33	11,813±2,196	0.001	9,761±1,860	0.001
	MEP	3,988±1,074	0.9	4,032±1,151	0.04	5,193±1,164	0.002
	HEP	1,107±624	0.75	1,176±711	0.003	2,483±1,300	0.001
	LEPs	4,842±1,400	0.29	4,478±1,267	0.001	3,262±1,106	<0.001
	LEPi	7,677±1,660	0.15	6,943±1,764	0.007	5,939±1,230	0.004
	LEPs/LEPi	0.641±0.170	0.88	0.646±0.128	0.047	0.548±0.157	0.12

Note: The statistically significant variations of the parameters are marked in bold.

Abbreviations: HEP, high echogenic pixels; LEP, low echogenic pixels; MEP, middle echogenic pixel; LEPs, low echogenic pixels in the upper dermis; LEPi, low echogenic pixels in the lower dermis.