Patient's global assessment of acne condition improvement at Day 78 (last protocol visit). The score range is -1 to 3, with higher scores denoting better outcomes, better acne condition improvement from baseline. Score ranges details: -1 (worse), 0 (no improvement), 1 (good improvement), 2 (very good improvement) on Day 78 (last protocol visit).

At the end of the study, the local tolerance on the skin of the product has been assessed during the clinical examination by the investigator by the "Local tolerance scale" (from 0 to 3, where higher scores mean better outcome) according to the following scores: 0= bad tolerance; 1= moderate tolerance; 2= good tolerance and 3= very good tolerance.

Count and percentage of subjects who answered satisfactorily to the 17-item questionnaire that measured patients' satisfaction after use of Crystal Peel in treating acne at Day 78 (final protocol visit).

Collection of adverse events by the investigator. Please refer to Adverse Events tables for more details.

Front face image with parallel polarization will be analyzed. A region of interest is defined on the cheek near the nose of each subject at baseline, it has the same size for all subjects and is automatically repositioned at other timepoints for the same subject, thanks to a spatial registration algorithm. The conspicuous number is defined as the number of distinct elements in the segmentation. A decrease of the conspicuous number of pores results in a decrease of the number of pores that are detected by the algorithm. There is an improvement of pores if and only if one of the following parameters is decreasing and the other ones are stable (no statistically significance) or decreasing: conspicuous number, conspicuous area, average area, conspicuous density, conspicuous depth and conspicuous volume of detected pores.

Front face image with parallel polarization will be analyzed. A region of interest is defined on the cheek near the nose of each subject at baseline, it has the same size for all subjects and is automatically repositioned at other timepoints for the same subject, thanks to a spatial registration algorithm. The conspicuous area is defined as the total number of pixels in the segmentation (total surface of detected pores). A decrease of the conspicuous area results in a decrease of the total surface occupied by detected pores. There is an improvement of pores if and only if one of the following parameters is decreasing and the other ones are stable (no statistically significance) or decreasing: conspicuous number, conspicuous area, average area, conspicuous density, conspicuous depth and conspicuous volume of detected pores.

Front face image with parallel polarization will be analyzed. A region of interest is defined on the cheek near the nose of each subject at baseline, it has the same size for all subjects and is automatically repositioned at other timepoints for the same subject, thanks to a spatial registration algorithm.The relative area is defined as the area of segmentation divided by total area of the region of interest. A decrease of conspicuous relative area results in a decrease of the detected pores conspicuous density. There is an improvement of pores if and only if one of the following parameters is decreasing and the other ones are stable (no statistically significance) or decreasing: conspicuous number, conspicuous area, average area, conspicuous density, conspicuous depth and conspicuous volume of detected pores.

Front face image with parallel polarization will be analyzed. A region of interest is defined on the cheek near the nose of each subject at baseline, it has the same size for all subjects and is automatically repositioned at other timepoints for the same subject, thanks to a spatial registration algorithm. The conspicuous depth is defined as the difference of intensity between detected pores segmentation and surrounding segmentation. It is an average value over the whole region of interest. A decrease of conspicuous depth results in a decrease of detected pores visibility. There is an improvement of pores if and only if one of the following parameters is decreasing and the other ones are stable (no statistically significance) or decreasing: conspicuous number, conspicuous area, average area, conspicuous density, conspicuous depth and conspicuous volume of detected pores.

Front face image with parallel polarization will be analyzed. A region of interest is defined on the cheek near the nose of each subject at baseline, it has the same size for all subjects and is automatically repositioned at other timepoints for the same subject, thanks to a spatial registration algorithm. The average area is defined as the area of segmentation divided by the number of distinct elements in the segmentation. It represents the average area of one detected pore. A decrease of the average area results in a decrease of the average size of detected pores or remaining detected pores if number decreases. There is an improvement of pores if and only if one of the following parameters is decreasing and the other ones are stable (no statistically significance) or decreasing: conspicuous number, conspicuous area, average area, conspicuous density, conspicuous depth and conspicuous volume of detected pores.

Front face image with parallel polarization will be analyzed. A region of interest is defined on the cheek near the nose of each subject at baseline, it has the same size for all subjects and is automatically repositioned at other timepoints for the same subject, thanks to a spatial registration algorithm. The conspicuous volume is defined as the multiplication of conspicuous area and conspicuous depth. A decrease of conspicuous volume results in a decrease of detected pores visibility. There is an improvement of pores if and only if one of the following parameters is decreasing and the other ones are stable (no statistically significance) or decreasing: conspicuous number, conspicuous area, average area, conspicuous density, conspicuous depth and conspicuous volume of detected pores.

Profiles images with parallel polarization will be analyzed by colorface device. A region of interest is delimited on the cheek of each subject at baseline and it is automatically repositioned at other timepoints for the same subject, thanks to a spatial registration algorithm. The conspicuous total area is defined as the number of pixels in segmentation of detected line marks. A decrease of conspicuous area results in a decrease of the total size of cheek line marks. There is an improvement of line marks if and only if one of the following parameters is decreasing and others ones are stable (no statistically significance) or decreasing: conspicuous area (unit=number of pixels), conspicuous length (unit=number of pixels), conspicuous depth (unit=arbitrary unit) and conspicuous volume of line marks (unit=arbitrary unit).

Profiles images with parallel polarization will be analyzed by Colorface device. A region of interest is delimited on the cheek of each subject at baseline and it is automatically repositioned at other timepoints for the same subject, thanks to a spatial registration algorithm. The average conspicuous depth is defined as the difference of intensity between segmentation and surrounding segmentation. A decrease of conspicuous depth results in a decrease of cheek line marks visibility. There is an improvement of line marks if and only if one of the following parameters is decreasing and others ones are stable (no statistically significance) or decreasing: conspicuous area (unit=number of pixels), conspicuous length (unit=number of pixels), conspicuous depth (unit=arbitrary unit) and conspicuous volume of line marks (unit=arbitrary unit).

Profiles images with parallel polarization will be analyzed by colorface device. A region of interest is delimited on the cheek of each subject at baseline and it is automatically repositioned at other timepoints for the same subject, thanks to a spatial registration algorithm. The conspicuous length is defined as the total number of pixels in the morphological skeleton of segmentation. The morphological skeleton is defined as the central element of unit width of segmentation of detected line marks. A decrease of conspicuous length results in a decrease of the cumulated length of detected cheek line marks. There is an improvement of line marks if and only if one of the following parameters is decreasing and others ones are stable (no statistically significance) or decreasing: conspicuous area (unit=number of pixels), conspicuous length (unit=number of pixels), conspicuous depth (unit=arbitrary unit) and conspicuous volume of line marks (unit=arbitrary unit).

Profiles images with parallel polarization will be analyzed by colorface device. A region of interest is delimited on the cheek of each subject at baseline and it is automatically repositioned at other timepoints for the same subject, thanks to a spatial registration algorithm. The conspicuous volume is defined as the multiplication of conspicuous area and conspicuous depth. A decrease of conspicuous volume results in a decrease of cheek line marks visibility. There is an improvement of line marks if and only if one of the following parameters is decreasing and others ones are stable (no statistically significance) or decreasing: conspicuous area (unit=number of pixels), conspicuous length (unit=number of pixels), conspicuous depth (unit=arbitrary unit) and conspicuous volume of line marks (unit=arbitrary unit).

Race and Ethnicity were not collected from any participant.

Fitzpatrick skin phototypes (from I to IV) used to characterize studied population. For guidance on Fitzpatrick skin phototypes, (Rünger 2019).

I: always burns, never tans. Pale white color of unexposed skin. II: always burns, then tans. White color of unexposed skin. III: sometimes burns, can tan without prior burn. White color of unexposed skin.

IV: usually does not burn, tans easily and deeply. White to light brown color of unexposed skin.

Investigator's global assessment of acne condition improvement at Day 78 (last protocol visit). The score range is -1 to 3, with higher scores denoting better outcomes, better acne condition improvement from baseline. Score ranges details: -1 (worse), 0 (no improvement), 1 (good improvement), 2 (very good improvement) on Day 78 (last protocol visit).

Per protocol (PP) population (any patient having used at least once the investigational device and without any major deviation to the clinical investigational plan).

Patient's global assessment of acne condition improvement at Day 78 (last protocol visit). The score range is -1 to 3, with higher scores denoting better outcomes, better acne condition improvement from baseline. Score ranges details: -1 (worse), 0 (no improvement), 1 (good improvement), 2 (very good improvement) on Day 78 (last protocol visit).

Per protocol (PP) population (any patient having used at least once the investigational device and without any major deviation to the clinical investigational plan).

At the end of the study, the local tolerance on the skin of the product has been assessed during the clinical examination by the investigator by the "Local tolerance scale" (from 0 to 3, where higher scores mean better outcome) according to the following scores: 0= bad tolerance; 1= moderate tolerance; 2= good tolerance and 3= very good tolerance.

Per protocol (PP) population (any patient having used at least once the investigational device and without any major deviation to the clinical investigational plan).

Count and percentage of subjects who answered satisfactorily to the 17-item questionnaire that measured patients' satisfaction after use of Crystal Peel in treating acne at Day 78 (final protocol visit).

Per protocol (PP) population (any patient having used at least once the investigational device and without any major deviation to the clinical investigation plan.

Collection of adverse events by the investigator. Please refer to Adverse Events tables for more details.

Safety population: any subject having used the investigational device. 33 patients have been analyzed.

Front face image with parallel polarization will be analyzed. A region of interest is defined on the cheek near the nose of each subject at baseline, it has the same size for all subjects and is automatically repositioned at other timepoints for the same subject, thanks to a spatial registration algorithm. The conspicuous number is defined as the number of distinct elements in the segmentation. A decrease of the conspicuous number of pores results in a decrease of the number of pores that are detected by the algorithm. There is an improvement of pores if and only if one of the following parameters is decreasing and the other ones are stable (no statistically significance) or decreasing: conspicuous number, conspicuous area, average area, conspicuous density, conspicuous depth and conspicuous volume of detected pores.

Per protocol (PP) population (any patient having used at least once the investigational device and without any major deviation to the clinical investigational plan).

Front face image with parallel polarization will be analyzed. A region of interest is defined on the cheek near the nose of each subject at baseline, it has the same size for all subjects and is automatically repositioned at other timepoints for the same subject, thanks to a spatial registration algorithm. The conspicuous area is defined as the total number of pixels in the segmentation (total surface of detected pores). A decrease of the conspicuous area results in a decrease of the total surface occupied by detected pores. There is an improvement of pores if and only if one of the following parameters is decreasing and the other ones are stable (no statistically significance) or decreasing: conspicuous number, conspicuous area, average area, conspicuous density, conspicuous depth and conspicuous volume of detected pores.

Per protocol (PP) population (any patient having used at least once the investigational device and without any major deviation to the clinical investigational plan).

Front face image with parallel polarization will be analyzed. A region of interest is defined on the cheek near the nose of each subject at baseline, it has the same size for all subjects and is automatically repositioned at other timepoints for the same subject, thanks to a spatial registration algorithm.The relative area is defined as the area of segmentation divided by total area of the region of interest. A decrease of conspicuous relative area results in a decrease of the detected pores conspicuous density. There is an improvement of pores if and only if one of the following parameters is decreasing and the other ones are stable (no statistically significance) or decreasing: conspicuous number, conspicuous area, average area, conspicuous density, conspicuous depth and conspicuous volume of detected pores.

Per protocol (PP) population (any patient having used at least once the investigational device and without any major deviation to the clinical investigational plan).

Front face image with parallel polarization will be analyzed. A region of interest is defined on the cheek near the nose of each subject at baseline, it has the same size for all subjects and is automatically repositioned at other timepoints for the same subject, thanks to a spatial registration algorithm. The conspicuous depth is defined as the difference of intensity between detected pores segmentation and surrounding segmentation. It is an average value over the whole region of interest. A decrease of conspicuous depth results in a decrease of detected pores visibility. There is an improvement of pores if and only if one of the following parameters is decreasing and the other ones are stable (no statistically significance) or decreasing: conspicuous number, conspicuous area, average area, conspicuous density, conspicuous depth and conspicuous volume of detected pores.

Per protocol (PP) population (any patient having used at least once the investigational device and without any major deviation to the clinical investigational plan).

Front face image with parallel polarization will be analyzed. A region of interest is defined on the cheek near the nose of each subject at baseline, it has the same size for all subjects and is automatically repositioned at other timepoints for the same subject, thanks to a spatial registration algorithm. The average area is defined as the area of segmentation divided by the number of distinct elements in the segmentation. It represents the average area of one detected pore. A decrease of the average area results in a decrease of the average size of detected pores or remaining detected pores if number decreases. There is an improvement of pores if and only if one of the following parameters is decreasing and the other ones are stable (no statistically significance) or decreasing: conspicuous number, conspicuous area, average area, conspicuous density, conspicuous depth and conspicuous volume of detected pores.

Per protocol (PP) population (any patient having used at least once the investigational device and without any major deviation to the clinical investigational plan).

Front face image with parallel polarization will be analyzed. A region of interest is defined on the cheek near the nose of each subject at baseline, it has the same size for all subjects and is automatically repositioned at other timepoints for the same subject, thanks to a spatial registration algorithm. The conspicuous volume is defined as the multiplication of conspicuous area and conspicuous depth. A decrease of conspicuous volume results in a decrease of detected pores visibility. There is an improvement of pores if and only if one of the following parameters is decreasing and the other ones are stable (no statistically significance) or decreasing: conspicuous number, conspicuous area, average area, conspicuous density, conspicuous depth and conspicuous volume of detected pores.

Per protocol (PP) population (any patient having used at least once the investigational device and without any major deviation to the clinical investigational plan).

Profiles images with parallel polarization will be analyzed by colorface device. A region of interest is delimited on the cheek of each subject at baseline and it is automatically repositioned at other timepoints for the same subject, thanks to a spatial registration algorithm. The conspicuous total area is defined as the number of pixels in segmentation of detected line marks. A decrease of conspicuous area results in a decrease of the total size of cheek line marks. There is an improvement of line marks if and only if one of the following parameters is decreasing and others ones are stable (no statistically significance) or decreasing: conspicuous area (unit=number of pixels), conspicuous length (unit=number of pixels), conspicuous depth (unit=arbitrary unit) and conspicuous volume of line marks (unit=arbitrary unit).

Intent-to-treat (ITT) population: any subject included in the study with at least a post-basal value.

Profiles images with parallel polarization will be analyzed by Colorface device. A region of interest is delimited on the cheek of each subject at baseline and it is automatically repositioned at other timepoints for the same subject, thanks to a spatial registration algorithm. The average conspicuous depth is defined as the difference of intensity between segmentation and surrounding segmentation. A decrease of conspicuous depth results in a decrease of cheek line marks visibility. There is an improvement of line marks if and only if one of the following parameters is decreasing and others ones are stable (no statistically significance) or decreasing: conspicuous area (unit=number of pixels), conspicuous length (unit=number of pixels), conspicuous depth (unit=arbitrary unit) and conspicuous volume of line marks (unit=arbitrary unit).

Intent-to-treat (ITT) population: any subject included in the study with at least a post-basal value.

Profiles images with parallel polarization will be analyzed by colorface device. A region of interest is delimited on the cheek of each subject at baseline and it is automatically repositioned at other timepoints for the same subject, thanks to a spatial registration algorithm. The conspicuous length is defined as the total number of pixels in the morphological skeleton of segmentation. The morphological skeleton is defined as the central element of unit width of segmentation of detected line marks. A decrease of conspicuous length results in a decrease of the cumulated length of detected cheek line marks. There is an improvement of line marks if and only if one of the following parameters is decreasing and others ones are stable (no statistically significance) or decreasing: conspicuous area (unit=number of pixels), conspicuous length (unit=number of pixels), conspicuous depth (unit=arbitrary unit) and conspicuous volume of line marks (unit=arbitrary unit).

Intent-to-treat (ITT) population: any subject included in the study with at least a post-basal value.

Profiles images with parallel polarization will be analyzed by colorface device. A region of interest is delimited on the cheek of each subject at baseline and it is automatically repositioned at other timepoints for the same subject, thanks to a spatial registration algorithm. The conspicuous volume is defined as the multiplication of conspicuous area and conspicuous depth. A decrease of conspicuous volume results in a decrease of cheek line marks visibility. There is an improvement of line marks if and only if one of the following parameters is decreasing and others ones are stable (no statistically significance) or decreasing: conspicuous area (unit=number of pixels), conspicuous length (unit=number of pixels), conspicuous depth (unit=arbitrary unit) and conspicuous volume of line marks (unit=arbitrary unit).

Intent-to-treat (ITT) population: any subject included in the study with at least a post-basal value.

Descriptive analysis of subjects' satisfaction questionnaire assessing the Crystal Peel in the treatment of acne.

Descriptive analysis of subjects' satisfaction questionnaire assessing the Crystal Peel in the treatment of acne.

Descriptive analysis of subjects' satisfaction questionnaire assessing the Crystal Peel in the treatment of acne.

Descriptive analysis of subjects' satisfaction questionnaire assessing the Crystal Peel in the treatment of acne.

Descriptive analysis of subjects' satisfaction questionnaire assessing the Crystal Peel in the treatment of acne.

Descriptive analysis of subjects' satisfaction questionnaire assessing the Crystal Peel in the treatment of acne.

Descriptive analysis of subjects' satisfaction questionnaire assessing the Crystal Peel in the treatment of acne.

Comparison of change from baseline of conspicuous number of detected pores at Day 57 to evaluate the improvement of pores assessed by Colorface device.

If the test provides a p-value less than 0.05, there is a significant variation over time for the analyzed parameter.

Comparison of change from baseline of conspicuous number of detected pores at day 78 to evaluate the improvement of pores assessed by Colorface device.

If the test provides a p-value less than 0.05, there is a significant variation over time for the analyzed parameter.

Comparison of change from baseline of conspicuous area of detected pores at day 57 to evaluate the improvement of pores assessed by Colorface device.

If the test provides a p-value less than 0.05, there is a significant variation over time for the analyzed parameter.

Comparison of change from baseline of conspicuous area of detected pores at day 78 to evaluate the improvement of pores assessed by Colorface device.

If the test provides a p-value less than 0.05, there is a significant variation over time for the analyzed parameter.

Comparison of change from baseline of conspicuous relative area (density) of detected pores at Day 57 to evaluate the improvement of pores assessed by Colorface device.

If the test provides a p-value less than 0.05, there is a significant variation over time for the analyzed parameter.

Comparison of change from baseline of conspicuous relative area (density) of detected pores at Day 78 to evaluate the improvement of pores assessed by Colorface device.

If the test provides a p-value less than 0.05, there is a significant variation over time for the analyzed parameter.

Comparison of change from baseline of conspicuous depth of detected pores at Day 57 to evaluate the improvement of pores assessed by Colorface device.

If the test provides a p-value less than 0.05, there is a significant variation over time for the analyzed parameter.

Comparison of change from baseline of conspicuous depth of detected pores at Day 78 to evaluate the improvement of pores assessed by Colorface device.

If the test provides a p-value less than 0.05, there is a significant variation over time for the analyzed parameter.

Comparison of change from baseline of average area of detected pores at Day 57 to evaluate the improvement of pores assessed by Colorface device.

If the test provides a p-value less than 0.05, there is a significant variation over time for the analyzed parameter.

Comparison of change from baseline of average area of detected pores at Day 78 to evaluate the improvement of pores assessed by Colorface device.

If the test provides a p-value less than 0.05, there is a significant variation over time for the analyzed parameter.

Comparison of change from baseline of conspicuous volume of detected pores at Day 57 to evaluate the improvement of pores assessed by Colorface device.

If the test provides a p-value less than 0.05, there is a significant variation over time for the analyzed parameter.

Comparison of change from baseline of conspicuous volume of detected pores at Day 78 to evaluate the improvement of pores assessed by Colorface device.

If the test provides a p-value less than 0.05, there is a significant variation over time for the analyzed parameter.