A plea for standardization of confocal microscopy and optical coherence tomography parameters to evaluate physiological and para‐physiological skin conditions in cosmetic science

Abstract

Non‐invasive reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) have been extended to the dermo‐cosmetic field, for skin pathophysiology understanding and therapeutics monitoring. However, standardized methodology and parameters to interpret structures and changes in these settings are still lacking. Present study aimed to propose a validated standard methodology and a list of defined parameters for objective non‐pathological skin assessments in the cosmetically sensitive cheekbone area of the face. OCT and RCM quantitative, semi‐quantitative and qualitative features were considered for assessments. Validation process included 50 sets of images divided into two age groups. Inter‐rater reliability was explored to assess the influence of the proposed methodology. Quantitative OCT parameters of “epidermal thickness,” “density and attenuation coefficients” and “vascular density” were considered and calculated. Severity scales were developed for semi‐quantitative OCT features of “disruption of collagen” and “vascular asset,” while extent scales were produced for semi‐quantitative RCM “irregular honeycomb,” “mottled pigmentation” and “polycyclic papillary contours.” Qualitative assessment was obtained for RCM type of collagen, and comparison between age groups was performed for all features considered. Severity visual scales assistance proved excellent inter‐rater agreement across all semi‐quantitative and qualitative domains. The assistance of shareable software systems allows for objective OCT quantitative parameters measurement. The use of standard reference scales, within a defined assessment methodology, offers high inter‐rater reliability and thus reproducibility for semi‐quantitative and qualitative OCT and RCM parameters. Taken together, our results may represent a starting point for a standardized application of RCM and OCT in dermo‐cosmetic research and practice.

New insights from non‐invasive imaging: from prospection of skin photodamages to training with mobile application

“…In particular, RCM and OCT have shown excellent correlations with histopathology in the diagnosis of skin cancers 19 and inflammatory skin diseases (reviewed in Ref. [20]). Both techniques are complementary: RCM enables cells to be visualized with a very high resolution, but cannot be used to examine cells deeper within the skin (i.e.…”

“…Collagen alterations can be observed by both RCM (loss of thin collagen fibres and the presence of collagen clods) 23 and OCT (disruption of collagen fibres). 20 As regards photoaged phenotypes, there is no single morphotype and it is not possible to determine which subjects have received more solar exposure during their lifetime on the basis of pictures of their skin. Clinically, two photoaging phenotypes have been described, either atrophic or hypertrophic.…”

Assessing changes in facial skin quality using noninvasive in vivo clinical skin imaging techniques after use of a topical retinoid product in subjects with moderate‐to‐severe photodamage

“…VivoSight D-OCT image acquisition and evaluation D-OCT images were acquired and analyzed as previously described. 12 Briefly, D-OCT images were taken of an investigator-selected area on the subjects' face, which was kept consistent for all follow-up visits.…”

Efficacy assessment of a TCA/H2O2 compositum for skin ageing treatment by confocal laser microscopy and optical coherence tomography

“…Efficacy assessment of a TCA/ H2O2 compositum for skin ageing treatment by confocal laser microscopy and optical coherence tomography Dear Editor, Skin ageing is a complex phenomenon linked to intrinsic and extrinsic factors, such as ultraviolet exposure, smoking or pollution, [1][2][3][4] which involves all skin layers. [5][6][7] Ageing is characterized by a reduction in collagen synthesis, 4,8,9 a decreased hydration, 5,6 epidermal thickness variations, 7 and an accelerated breakdown and disorganization of collagen fibres 4,8,9 as well as loss of skin elasticity. 10 Chemical peelings can potentially help to reverse these degenerative processes.…”

“…Images were acquired at baseline (V0), six weeks (V6) and 12 weeks (V7) after treatment and assessed according to recently standardized protocols. 7,8 Additionally, a patient satisfaction questionnaire (from 0 'not satisfied' to 3 'very satisfied') was administered to patients. All adverse after the procedure were recorded.…”