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Background: Stretch marks or striae distensae (SD) are characterized by epidermal atrophy following repeated over-stretching of the skin tissue. The objective of this study was to investigate the skin texture and microstructure of SD lesions compared to those of normal adjacent skin in vivo using non-invasive methods., Methods: A population of 26 women and 3 men with SD were examined after giving written informed consent. Following clinical grading, skin replicas were collected, confocal microscopy was performed on SD lesions and healthy neighboring skin. Skin surface texture parameters were calculated using 3D image analysis of the skin replicas and epidermal and dermal microstructure were evaluated by analysis of the confocal images. In a parallel study, histological analysis was performed on 6 skin biopsies taken from abdominal reduction surgeries in areas where skin exhibited SD., Results: Analysis of the skin surface texture showed that the SD area was more anisotropic and with higher skin roughness than the adjacent skin in terms of directions of skin microglyphics. Confocal microscopy demonstrated that SD were characterized by shallower dermal papillae (P < 0.05) and that dermal papillae height inversely correlated to the intensity of collagen alignment on the SD sites (P < 0.05). The histology findings confirmed the in vivo confocal microscopy findings., Conclusions: The skin structure of SD is qualitatively and quantitatively different compared to healthy skin. Altered skin relief reflects structural modifications in the dermis. Flattening of the dermal-epidermal junction maybe functionally related to the observed collagen fiber alignment. Observations by non-invasive methods were in line with the histological findings and therefore relevant in studies assessing the efficacy of SD treatment options., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: The overall appearance of an aged skin is characterized by a combination of several attributes such as wrinkles, brown spots and sagging. Our objective was to develop and validate a statistical framework to assess the overall anti-ageing benefits of products/procedures., Method: Different skin attributes were evaluated by a clinical grader and combined using a Principal Component Analysis (PCA). The Skin Ageing Index was defined as the normalized projection of the clinical grading values on the first PCA axis. Several Skin Indexes were built by grouping specific parameters related to a skin condition such as overall ageing, wrinkles and sagging. The method was validated following two steps. Firstly, a clinical study was performed on 173 Caucasian women and the correlation between the Skin Indexes and the volunteers' real and perceived age was estimated. Secondly, a double-blinded placebo-controlled randomized study was performed on 87 Caucasian women to assess the efficacy of an anti-wrinkle cream containing retinol, hyaluronic acid and dihydroxymethylchromone. Facial wrinkles were clinically evaluated and a Wrinkle Index was built., Results: All indexes were highly correlated with the real and the perceived age (0.57 ≤ Pearson R ≤ 0.92, P-value ≤ 0.05). Finally, the Wrinkle Index provides documented evidence that the tested product significantly reduced the appearance of wrinkles versus the placebo and the baseline assessment (-23.53% after 4 weeks, -27.83% after 8 weeks)., Conclusion: Skin ageing Indexes capture information relevant to the visual transformation of facial skin with age, while providing documented product benefits. These tools may enable a simpler and more consistent comparison of anti-ageing products/procedures., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)