Proposal for anin vivohistopathologic scoring system for skin aging by means of confocal microscopy

Line-field confocal optical coherence tomography coupled with artificial intelligence algorithms to identify quantitative biomarkers of facial skin ageing

Quantitative biomarkers of facial skin ageing were studied from one hundred healthy Caucasian female volunteers, aged 20-70 years, using in vivo 3D Line-field Confocal Optical Coherence Tomography (LC-OCT) imaging coupled with Artificial Intelligence (AI)-based quantification algorithms. Layer metrics, i.e. stratum corneum thickness (SC), viable epidermal thickness and Dermal-Epidermal Junction (DEJ) undulation, as well as cellular metrics were measured for the temple, cheekbone and mandible. For all three investigated facial areas, minimal age-related variations were observed in the thickness of the SC and viable epidermis layers. A flatter and more homogeneous epidermis (decrease in the standard deviation of the number of layers means), a less dense cellular network with fewer cells per layer (decrease in cell surface density), and larger and more heterogeneous nuclei within each layer (increase in nuclei volume and their standard deviation) were found with significant variations with age. The higher atypia scores further reflected the heterogeneity of nuclei throughout the viable epidermis. The 3D visualisation of fine structures in the skin at the micrometric resolution and the 1200 µm × 500 µm field of view achieved with LC-OCT imaging enabled to compute relevant quantitative biomarkers for a better understanding of skin biology and the ageing process in vivo.

Laser Treatment Monitoring with Reflectance Confocal Microscopy

Laser treatments have become popular in Dermatology. In parallel to technologic development enabling the availability of different laser wavelengths, non-invasive skin imaging techniques, such as reflectance confocal microscopy (RCM), have been used to explore morphologic and qualitative skin characteristics. Specifically, RCM can be applied to cosmetically sensitive skin areas such as the face, without the need for skin biopsies. For these reasons, apart from its current use in skin cancer diagnosis, our systematic review reveals how RCM can be employed in the field of laser treatment monitoring, being particularly suitable for the evaluation of variations in epidermis and dermis, and pigmentary and vascular characteristics of the skin. This systematic review article aims to provide an overview on current applications of RCM laser treatment monitoring, while describing RCM features identified for different applications. Studies on human subjects treated with laser treatments, monitored with RCM, were included in the current systematic review. Five groups of treatments were identified and described: skin rejuvenation, scar tissue, pigmentary disorders, vascular disorders and other. Interestingly, RCM can assist treatments with lasers targeting all chromophores in the skin and exploiting laser induced optical breakdown. Treatment monitoring encompasses assessment at baseline and examination of changes after treatment, therefore revealing details in morphologic alterations underlying different skin conditions and mechanisms of actions of laser therapy, as well as objectify results after treatment.

Evaluation of Morphological and Structural Skin Alterations on Diabetic Subjects by Biophysical and Imaging Techniques

Diabetes causes increased production of advanced glycation end products (AGEs), which may lead to irreversible damage to collagen fibers, and early and more accentuated signs of skin aging. Thus, the objective of this study was to evaluate diabetic skin's mechanical and morphological characteristics and compare these to healthy skin. Twenty-eight female participants aged between 39 and 55 years were enrolled: half had type 2 diabetes, and the others were healthy. Wrinkles, transepidermal water loss (TEWL), stratum corneum water content, skin color, elasticity, morphological and structural characteristics of epidermis and dermis echogenicity were evaluated using biophysical and skin imaging techniques. Higher TEWL values were observed in participants with diabetes, who also showed lower skin elasticity and wrinkles with greater volume, area, and depth. In addition, the Reflectance Confocal Microscopy (RCM) imaging analysis showed that all participants with diabetes presented polycyclic papillae and deformed and amorphous collagen fibers. The obtained data showed significant differences between healthy and diabetic skin and could help develop more specific topical treatments to improve the treatment of skin conditions in people with diabetes. Finally, RCM is an advanced imaging technique that allows for a more profound analysis of diabetic skin, which could assist in the evaluation of dermocosmetic treatments to improve the skin alterations caused by this disease.

The CSIESA: A Novel Score for the Assessment of Intrinsic and Extrinsic Skin Aging Based on Reflectance Confocal Microscopy Imaging

Skin aging is an intricate physiological process governed by intrinsic and extrinsic factors. Increasing life expectancy has turned skin aging into a growing concern for the general population. Clinical examination of the skin does not fully describe the skin aging process. This study aims to evaluate the healthy skin of five different age groups in order to develop an easy-to-use confocal score for quantifying signs of skin aging and test the correlation between this new score and the already described clinical score, SCINEXA (score of intrinsic and extrinsic skin aging). Thirty-five subjects split into five age groups: <35; 36−45; 46−55; 56−65, and >65 years old were enrolled. Clinical signs were quantified using the SCINEXA score, and known confocal variables of skin aging were evaluated. Three different semi-quantitative scores were calculated: epidermal disarrangement score (EDS), epidermal hyperplasia score (EHS), and dermal score (DS). The EDS showed a stable trend up to the age of 65 and a dramatic increase in older subjects. EHS was characterized by an ascending trend from younger subjects to middle-aged ones. The DS was progressive with age, with a different proportion of distinct collagen types. The confocal CSIESA (confocal score for the assessment of intrinsic and extrinsic skin aging) score correlated well with the SCINEXA score. Reflectance confocal microscopy is a powerful, non-invasive technique for microscopically quantifying aging signs.

Application of a Reflectance Confocal Microscopy Imaging Analysis Score for the Evaluation of Non-Melanogenic Changes in Male Photoaged Skin

The photoaging process is characterized by skin changes due to ultraviolet radiation exposure and is the principal environmental factor affecting skin aging. Reflectance confocal microscopy permits noninvasive skin imaging to understand how the photoaging process may change skin. Since men do not habitually use a sunscreen, the application of skin imaging techniques is important to understand the influence of sunlight on their skin health. The aim of this study was to develop a score based on RCM imaging analyses to evaluate the morphological and structural changes of the photoaged skin according to literature data. The score was applied in order to determine possible correlations between chronological aging and sunscreen use behavior among men. Thus, 40 men aged 18 to 50 years were recruited, images from the frontal region of their skin were obtained and the score was applied. It was observed that habits are more important than age for the skin photoaging process. Men with photoprotection habits showed overall better skin morphological and structural characteristics regardless of age, demonstrating that sun protection behavior is a major key factor in the understanding of photoaging, so that men should be encouraged to start the use of cosmetic products and to perform selfcare.

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

BACKGROUND

Studies utilizing reflectance confocal microscopy (RCM) and dynamic optical coherence tomography (D-OCT) to assess cosmetic skin changes are limited.

METHODS

A 12-week, open-label study was conducted using RCM and D-OCT to evaluate the effects of a topical cosmetic retinol (RET05) on subjects with facial photodamage. Study endpoints included investigator grading, standardized (VISIA-CR) and 3D photography (Antera 3D), independent RCM (VivaScope1500) and D-OCT (VivoSight) image analysis, validated FACE-Q scales, and subject questionnaires.

RESULTS

Twenty-three subjects, 45- to 68-year old, with Fitzpatrick skin types II-IV completed the study. After 12 weeks of repeated application, RET05 demonstrated significant corresponding cosmetic improvements for overall photodamage, skin tone unevenness, tactile roughness, fine lines/wrinkles (forehead, periocular, and perioral), and coarse lines/wrinkles (forehead, periocular, and cheeks), and Allergan Skin Roughness Scale. FACE-Q assessments also demonstrated significant improvements from baseline at week 12. RCM analysis showed decreases in all epidermis, less compact stratum corneum (SC), more non-compact SC, decreases in coarse/huddled dermal fibers, and increases in fibrillar dermal fibers, as compared to baseline. D-OCT analysis showed significant decreases in epidermal thickness (ET), reduction of moderate/many collagen fragments and collagen bundles, and significant increases in the stroma attenuation coefficient and collagen density. Moreover, the dermal-epidermal junction was more pronounced, and vascular abundance at 300 and 500 μm depth increased. Independent evaluation of RCM and D-OCT images showed similar decreases in ET and improvements in dermal fibers.

CONCLUSION

This study was the first to utilize RCM and D-OCT to evaluate the cosmetic effects of a topical retinoid and further substantiate improvements in skin quality.

[Ex vivo confocal laser scanning microscopy for melanocytic lesions and autoimmune diseases]

BACKGROUND

Ex vivo confocal laser scanning microscopy (CLSM) enables bedside histology and offers the surgeon a direct intraoperative tissue examination.

OBJECTIVES

To determine whether this innovative, ultra-fast diagnostic tool can be expanded beyond nonmelanoma skin cancer, particularly basal cell carcinoma, to other indications including melanocytic lesions and autoimmune diseases.

MATERIALS AND METHODS

Review of literature and summary of the current knowledge and experience of the use of ex vivo CLSM in melanocytic lesions and in autoimmune diseases.

RESULTS

Up to date experience of the use of ex vivo CLSM in melanocytic lesions and in autoimmune diseases is limited but promising. Current knowledge on melanocytic lesions in ex vivo CLSM and their examples together with classic ex vivo CLSM features are presented. Previous results on the use of ex vivo CLSM in autoimmune dermatoses are presented, and future application possibilities of ex vivo CLSM are discussed.

CONCLUSIONS

The method is particularly suitable for the rapid examination of basal cell carcinomas during Mohs surgery but could also be used in the future for the intraoperative examination of melanocytic and autoimmune skin lesions.

Oral Supplementation with Hydrolyzed Fish Cartilage Improves the Morphological and Structural Characteristics of the Skin: A Double-Blind, Placebo-Controlled Clinical Study

Collagen and its peptides are natural ingredients used in food supplements and nutricosmetics with the claim of providing benefits for skin health and beauty. In this context, the aim of the present study was to evaluate the clinical efficacy of oral supplementation with hydrolyzed fish cartilage for the improvement of chronological and photoaging-induced skin changes. A total of 46 healthy females aged 45 to 59 years were enrolled and divided into two groups: G1-placebo and G2-oral treatment with hydrolyzed fish cartilage. Measurements of skin wrinkles, dermis echogenicity and thickness, and morphological and structural characteristics of the skin were performed in the nasolabial region of the face before and after a 90-day period of treatment using high-resolution imaging, ultrasound, and reflectance confocal microscopy image analyses. A significant reduction in wrinkles and an increase of dermis echogenicity were observed after a 90-day period of treatment with hydrolyzed fish cartilage compared to the placebo and baseline values. In addition, reflectance confocal microscopy (RCM) image analysis showed improved collagen morphology and reduced elastosis after treatment with hydrolyzed fish cartilage. The present study showed the clinical benefits for the skin obtained with oral supplementation with a low dose of collagen peptides from hydrolyzed fish cartilage.

Towards data-driven quantification of skin ageing using reflectance confocal microscopy

INTRODUCTION

Evaluation of skin ageing is a non-standardized, subjective process, with typical measures relying coarse, qualitatively defined features. Reflectance confocal microscopy depth stacks contain indicators of both chrono-ageing and photo-ageing. We hypothesize that an ageing scale could be constructed using machine learning and image analysis, creating a data-driven quantification of skin ageing without human assessment.

METHODS

En-face sections of reflectance confocal microscopy depth stacks from the dorsal and volar forearm of 74 participants (36/18/20 training/testing/validation) were represented using a histogram of visual features learned using unsupervised clustering of small image patches. A logistic regression classifier was trained on these histograms to differentiate between stacks from 20- to 30-year-old and 50- to 70-year-old volunteers. The probabilistic output of the logistic regression was used as the fine-grained ageing score for that stack in the testing set ranging from 0 to 1. Evaluation was performed in two ways: on the test set, the AUC was collected for the binary classification problem as well as by statistical comparison of the scores for age and body site groups. Final validation was performed by assessing the accuracy of the ageing score measurement on 20 depth stacks not used for training or evaluating the classifier.

RESULTS

The classifier effectively differentiated stacks from age groups with a test set AUC of 0.908. Mean scores were significantly different when comparing age groups (mean 0.70 vs. 0.44; t = -6.62, p = 0.0000) and also when comparing stacks from dorsal and volar body sites (mean 0.64 vs. 0.53; t = 3.12, p = 0.0062). On the final validation set, 17 out of 20 depth stacks were correctly labelled.

DISCUSSION

Despite being limited to only coarse training information in the form of example stacks from two age groups, the trained classifier was still able to effectively discriminate between younger skin and older skin. Curiously, despite being only trained with chronological age, there was still evidence for measurable differences in age scores due to sun exposure-with marked differences in scores on sun-exposed dorsal sites of some volunteers compared with less sun-exposed volar sites. These results suggest that fine-grained data-driven quantification of skin ageing is achievable.

Reflectance Confocal Microscopy of Aging Skin and Skin Cancer

Skin aging is a complex process that causes morphologic variations. Some of these variations have been hypothesized to be involved in skin cancer development. This paper reviews current knowledge of the features of aged skin as seen with reflectance confocal microscopy (RCM). Basic principles of the technique are described, and the RCM features of healthy skin and skin cancer are briefly discussed. Moreover, the RCM features at different layers of young and elderly skin are described, as are the variations that occur with passing years and in relation to sun exposure that contribute to photoaging and the development of skin cancer. RCM enables the noninvasive evaluation, at quasi-histologic resolution, of aging-related skin changes, some of which are shared with skin cancer; this ability helps avoid skin biopsy. Further research is needed to understand the relation between skin aging and skin cancer development.

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

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.

Visible characteristics and structural modifications relating to enlarged facial pores

BACKGROUND

Many factors relate to enlargement and visibility of facial pores. However, how enlargement relates to modification of the skin structure is still poorly analysed. Therefore, our aim was to characterise the visible features and the micro-environment of facial pores.

MATERIALS AND METHODS

We recruited 160 women, half of them with normal-size facial pores, the other half presenting enlarged pores. We analysed their right cheek using standardised photography, in vivo reflectance microscopy and optical coherence tomography.

RESULTS

If the area of pores is indeed the most differentiating visible characteristic, enlarged facial pores are also denser and more contrasted. At the structural level, enlarged facial pores present a more regular organisation of keratinocytes, an irregular dermo-epidermal junction and a higher attenuation of collagen between the surface and deeper layers. Still, the most relevant alterations of enlarged facial pores are the presence of bright tubular structures surrounding hair follicles and enlarged hair shafts.

CONCLUSION

These observations suggest that alterations of the stroma could result in altered skin tensions, leading to the dilation of the infundibulum and enlarged hair shaft. The modified tension would also explain the more regular organisation of the keratinocytes and the irregular dermo-epidermal junction.

Noninvasive skin imaging in esthetic medicine-Why do we need useful tools for evaluation of the esthetic procedures

BACKGROUND

Despite the constant development of aesthetic medicine, there is still a lack of objective methods to assess the effectiveness of antiaging treatments and their impact on the skin. Histopathological examination of the skin section provides most of the key information about the condition of the skin, but it is an invasive procedure that requires a skin biopsy, which may be associated with the formation of a scar that is considered to be an aesthetic defect. Non-invasive imaging methods of the skin like dermoscopy, skin ultrasonography and reflectance confocal microscopy may be a useful solution.

AIMS AND METHODS

In this systematic review, we present the possible application of noninvasive skin imaging methods in esthetic medicine. The literature search was conducted via medical database (PubMed, Google Scholar).

RESULTS

The research suggests the use of dermoscopy during laser therapy, for the targeted treatment of vascular lesions and appropriate adjustment of laser parameters. Skin ultrasonography, especially high-frequency ultrasonography, has been widely used in aesthetic medicine-during and after volumetric treatments and in the assessment of the effects of anti-cellulite therapies, treatments that correct discolorations and improve skin quality. Publications also highlight the importance of reflexive confocal microscopy in the evaluation of the results of anti-aging treatments using the fractional laser, moisturizing preparations or micro puncturing combined with hyaluronic acid injections.

CONCLUSION

Non-invasive skin imaging methods are useful tools for pre- and postoperative assessment in aesthetic medicine and their wide application may help to objectively assess the impact of anti-aging procedures on the skin.

A Dermonutrient Containing Special Collagen Peptides Improves Skin Structure and Function: A Randomized, Placebo-Controlled, Triple-Blind Trial Using Confocal Laser Scanning Microscopy on the Cosmetic Effects and Tolerance of a Drinkable Collagen Supplement

The purpose of this randomized, placebo-controlled, triple-blind trial on 60 healthy female volunteers was to assess the cosmetic effects on skin quality of a food supplement containing special collagen peptides together with acerola extract, vitamin C, vitamin E, biotin, and zinc after an intake of 12 weeks (Elasten^®, QUIRIS Healthcare, Germany). To reduce assessment bias maximally and increase the accuracy and objectivity of the outcomes, the trial design was triple blinded in a manner that neither the subjects nor the person administering the products nor the person who assessed the primary outcomes knew which subjects had received the test product and which had received the placebo. The expert grader assessing the confocal laser scanning microscopy images was additionally blinded regarding the time when the image was taken (on days 1 or 85). The objective, blinded, and validated image analyses using confocal laser scanning microscopy showed a significant improvement of the collagen structure of facial skin (primary endpoint) after intake of the test product, while no improvements were found after intake of the placebo. The proven positive nutritional effect on the collagen structure was fully consistent with positive subjective evaluations of relevant skin parameters such as elasticity, crinkliness/wrinkliness, and evenness in different body areas such as face, hands, décolleté, neck, backside, legs, and belly, all serving as secondary endpoints. The test product was found to be safe and very well tolerated. A cosmetically relevant improvement of the facial skin was demonstrated after administration of the collagen supplement.

Structural skin changes in elderly people investigated by reflectance confocal microscopy

BACKGROUND

Reflectance confocal microscopy (RCM) is particularly suitable for the study of skin ageing because it provides nearly histological information in vivo and non-invasively. However, there are no studies that evaluated RCM skin features of a large population older than 70 years.

OBJECTIVES

The aim of our investigation was to study age-related skin changes in an elderly population by RCM and to evaluate their topographical and gender differences.

METHODS

We obtained RCM images of photoprotected (volar arm) and chronic (face) and intermittently photoexposed (dorsal forearm) body sites of 209 volunteers (105 women and 104 men, mean age: 77.5, range 74-81 years). 15 previously reported and new RCM parameters related to skin ageing were assessed.

RESULTS

Photoexposed sites had thicker suprapapillary epidermis, more linear, distant and thin furrows, higher presence of mottled pigmentation, polycyclic papillae and coarse and huddled collagen and lower presence of dermal papillae than the photoprotected site. Irregular honeycomb pattern was not higher in photoexposed sites, indicating that it is probably more dependent on intrinsic ageing. Two ageing scores defined for facial skin ageing (epidermal disarray score and epidermal hyperplasia score) were found useful for the identification of photoageing. Gender differences only concerned some RCM parameters (i.e. thickness of different layers of the epidermis, furrows and collagen score) and some body sites, in line with the fact that women and men of our cohort had no major differences in clinically visible skin ageing.

CONCLUSIONS

Our study confirmed that RCM is a powerful non-invasive technique to microscopically quantify ageing signs and our observations contribute to highlight the differences between intrinsic and extrinsic ageing.

Reflectance confocal microscopy for noninvasive examination of nonmelanocytic tumors and virus-associated skin lesions in organ transplant recipients

BACKGROUND

Drug-induced immunosuppression is necessary to prevent rejection of the foreign organ in transplanted patients, but neoplastic and virus-associated skin diseases are frequent complications. Reflectance confocal microscopy (RCM) recently emerged as a promising tool for the early diagnosis of skin lesions.

MATERIALS AND METHODS

A total of 61 skin lesions, among them 20 basal cell carcinomas, six Bowen's diseases, 23 actinic keratoses, and 12 verrucae, were analyzed. All lesions were clinically evaluated followed by RCM evaluation by two independent dermatologists and histological examination.

RESULTS

For the diagnosis of basal cell carcinoma, a sensitivity of 100% by both investigators (INV I + II) and a specificity of 100% by INV I and 80% by INV II were achieved. The sensitivity average rate for RCM features reached by both investigators ranged between 60% and 100%, and the specificity between 55% and 90%. For the diagnosis of actinic keratosis, a concordant sensitivity of 94.4% and a specificity of 80% (INV I) and 60% (INV II) were detected. The sensitivity average rate of specific RCM criteria ranged between 72.3% and 97.2%, whereas specificity ranged between 20% and 90%. Regarding verrucae, RCM confirmed the histological diagnosis with a sensitivity of 85.7% (INV I) and 100% (INV II), while specificity was 100% and 80%, respectively.

CONCLUSION

Reflectance confocal microscopy resulted to be a reliable tool for the noninvasive diagnosis of neoplastic and virus-associated skin changes in organ transplant recipients. Nevertheless, given the frequency and diagnostic complexity of the hyperkeratotic lesions occurring post-transplantation, larger cohorts of patients are required to confirm and consolidate these findings.

Systematic review and proposal of an in vivo reflectance confocal microscopy assessment tool for cutaneous lymphoma

BACKGROUND

Reflectance confocal microscopy (RCM) is a non-invasive imaging technique that provides dynamic information and allows in vivo monitoring, with excellent histologic correlation. In the last decade, the use of RCM for cutaneous T-cell lymphomas (CTCL) has been reported. CTCL may require multiple biopsies for diagnosis due to its equivocal clinical presentation. RCM was described as a possible tool to help determine the best site for skin biopsy. This study aims to systematically review all RCM features reported in literature for CTCL.

METHOD

A systematic literature search concerning CTCL evaluated by RCM was performed in eight electronic databases until May 2019 following PRISMA-DTA quality assessment.

RESULTS

Eighteen RCM features were described in patients with CTCL. The most frequent were: interface dermatitis (89%), epidermal lymphocytes (82%), epidermal architectural disarray (81%), and vesicle-like structure (Pautrier microabscess) (51%).

CONCLUSION

In order to establish comparable parameters among the studies identified, we proposed descriptors for CTCL features and a grading system to quantify them. This will facilitate to define the role of RCM in the diagnosis and monitoring of CTCL patients.

Non-invasive monitoring of subclinical and clinical actinic keratosis of face and scalp under topical treatment with ingenol mebutate gel 150 mcg/g by means of reflectance confocal microscopy and optical coherence tomography: New perspectives and comparison of diagnostic techniques

Actinic keratosis (AK) corresponds to the earliest stage of in situ squamous cell carcinoma and arises on chronically sun-exposed skin. Around the clinically evident AKs, the apparently healthy epidermis may contain different grades of atypia that can be detected by noninvasive imaging techniques such as reflectance confocal microscopy (RCM) and optical coherence tomography (OCT). Subclinical actinic keratosis (sAK) has captured increasing interest as a potential target of field therapies. The aim of this study was to evaluate in vivo the changes in the field cancerization undergoing treatment with topical ingenol mebutate by combining RCM and OCT. Twenty patients with field cancerization of the face and scalp were treated with ingenol mebutate gel (150 mcg/g) for three consecutive days on an area of 25 cm² containing at least two AKs, two sAKs and two apparently healthy sites. About 120 lesions were evaluated through clinical investigation and clinical, dermoscopical, RCM and OCT images at day 0, 4, 14 and 56 based on the diagnostic criteria for AKs. Main pathological features improved in both AKs and sAKs, in particular the epidermal thickness measured by OCT and the epidermal atypia graded by RCM. Local skin reactions (LSR) arose predominantly in the lesional area compared with healthy skin. A complete clearance was detected in 58% for AKs, and in 55% and 72% for sAKs measured by RCM and OCT, respectively. Both OCT and RCM allow the morphological representation of field cancerization including subclinical lesions and provide complementary information. Ingenol mebutate is effective not only in clinically evident but also in sAKs. The differences in LSR highlight the potential selectivity of the treatment.

Three-dimensional conditional random field for the dermal-epidermal junction segmentation

The segmentation of the dermal-epidermal junction (DEJ) in in vivo confocal images represents a challenging task due to uncertainty in visual labeling and complex dependencies between skin layers. We propose a method to segment the DEJ surface, which combines random forest classification with spatial regularization based on a three-dimensional conditional random field (CRF) to improve the classification robustness. The CRF regularization introduces spatial constraints consistent with skin anatomy and its biological behavior. We propose to specify the interaction potentials between pixels according to their depth and their relative position to each other to model skin biological properties. The proposed approach adds regularity to the classification by prohibiting inconsistent transitions between skin layers. As a result, it improves the sensitivity and specificity of the classification results.

Ultrastructural and Molecular Analysis of Ribose-Induced Glycated Reconstructed Human Skin

Aging depicts one of the major challenges in pharmacology owing to its complexity and heterogeneity. Thereby, advanced glycated end-products modify extracellular matrix proteins, but the consequences on the skin barrier function remain heavily understudied. Herein, we utilized transmission electron microscopy for the ultrastructural analysis of ribose-induced glycated reconstructed human skin (RHS). Molecular and functional insights substantiated the ultrastructural characterization and proved the relevance of glycated RHS beyond skin aging. In particular, electron microscopy mapped the accumulation and altered spatial orientation of fibrils and filaments in the dermal compartment of glycated RHS. Moreover, the epidermal basement membrane appeared thicker in glycated than in non-glycated RHS, but electron microscopy identified longitudinal clusters of the finest collagen fibrils instead of real thickening. The stratum granulosum contained more cell layers, the morphology of keratohyalin granules decidedly differed, and the stratum corneum lipid order increased in ribose-induced glycated RHS, while the skin barrier function was almost not affected. In conclusion, dermal advanced glycated end-products markedly changed the epidermal morphology, underlining the importance of matrix⁻cell interactions. The phenotype of ribose-induced glycated RHS emulated aged skin in the dermis, while the two to three times increased thickness of the stratum granulosum resembled poorer cornification.

The investigation of the relationships of demodex density with inflammatory response and oxidative stress in rosacea

The relationships of demodex density with systemic oxidative stress, inflammatory response, and clinical severity in rosacea are not clear. This study aimed to (a) analyze the levels of systemic oxidative stress, antioxidant capacity, inflammatory parameters, and matrix metalloproteinases (MMPs) in systemic circulation in patients with rosacea, (b) identify the relationship between mite density and both oxidative stress and inflammation, and (c) investigate the role of photoaging and sebum secretion in etiopathogenesis. Forty patients with rosacea and 40 age-, sex-, and skin phenotype-matched healthy volunteers were included in the study. Clinical disease severity of the patients was determined. Sebum levels were measured in both the groups, and photoaging was evaluated. Reflectance confocal microscopy was used to calculate demodex density. Serum total antioxidant capacity (TAC), total oxidant capacity (TOC), myeloperoxidase (MPO), MMP-1, MMP-9, arylesterase (ARES), interleukin-1β (IL-1β), paraoxonase-1 (PON-1), and tumor necrosis factor-α (TNF-α) levels were also analyzed. The patients with rosacea had significantly higher serum TOC and lower TAC levels (p < 0.001). The serum ARES and PON-1 levels were significantly lower (p = 0.045 and p < 0.001, respectively); however, the serum levels of MMP-1, MMP-9, IL-1β and MPO were higher in the patient group. Demodex parameters were higher in the patient group compared to the control group. There was no significant correlation between the number of mites and disease severity. In addition, the number of mites was not correlated with the serum levels of TAC, TOC, OSI, MPO, MMP-1, MMP-9, ARES, PON-1, TNF-α, and IL-1β. However, sebum levels were directly proportional to the number of mites. Photoaging severity was similar between the patients and control subjects. The changing sebaceous microenvironment in rosacea leads to an increase in the number of demodex mites. However, increased demodex density does not alter disease severity, level of oxidative stress, or inflammation. Although none of the patients with rosacea had any underlying systemic disease, patients' systemic oxidative stress and inflammation parameters were found high in systemic circulation. It is assumed that the patients with rosacea are more prone to systemic diseases.

An updated review of clinical methods in the assessment of ageing skin - New perspectives and evaluation for claims support

With the advancement of skin research, today's consumer has increased access to an informed understanding of ageing skin and its appendages, together with a plethora of targeted products to meet such needs. In recent years, increased legislative demands for quality evidential claims support have led not only to the development and validation of clinical methods to measure and quantify ageing skin, but also a clearer understanding of the skin ageing process-especially the impact of both its internal and external environments-as well as a tougher stance on clearly unjustifiable claims. Traditional testing methods used to research and evaluate anti-ageing products claim to employ sophisticated instruments. Today, however, since the term anti-ageing can be considered a misnomer, intelligent use of combined more advanced clinical methods has enabled the development of technologically improved consumer products providing enhanced efficacy and targeted performance. Non-invasive methods for the assessment and quantification of the causes of ageing skin provide tools to the clinical researcher as defined by key clinically observed ageing parameters. Where evidence requires additional support, a number of clinical procedures evaluating ageing skin and hair products are combined with invasive procedures, thus enabling an added value to product claims. As discussed herein, given the enhanced understanding of ageing, we provide an update to our previous reviews of clinical methods used in the assessment of skin ageing, to include the wider aspects of environmental exposure; skin pigmentation; microbiome disturbance; surface topography; colour, radiance, and pH; and structural integrity-all requiring a disciplined approach to their use in dermatological investigations and product claims evidence.

Identification of ex-vivo confocal laser scanning microscopic features of melanocytic lesions and their histological correlates

Ex-vivo confocal laser scanning microscopy (CLSM) offers rapid tissue examination. Current literature shows promising results in the evaluation of non-melanoma skin cancer but little is known about presentation of melanocytic lesions (ML). This study evaluates ML with ex-vivo CLSM in comparison to histology and offers an overview of ex-vivo CLSM characteristics. 31 ML were stained with acridine orange or fluorescein and examined using ex-vivo CLSM (Vivascope2500^® ; Lucid Inc; Rochester NY) in reflectance and fluorescence mode. Confocal images were correlated to histopathology. Benign and malignant features of the ML were listed and results were presented. Sensitivity and specificity were calculated using contingency tables. The ML included junctional, compound, dermal, Spitz and dysplastic nevi, as well as various melanoma subtypes. The correlation of the confocal findings with histopathology allowed the identification of different types of ML and differentiation of benign and malignant features. The study offers an overview of confocal characteristics of ML in comparison to histology. Ex-vivo CLSM does not reproduce the typical in-vivo horizontal mosaics but rather reflects the vertical histological presentation. Not all typical in-vivo patterns are detectable here. These findings may help to evaluate the ex-vivo CLSM as an adjunctive tool in the immediate intraoperative diagnosis of ML. Superficial spreading malignant melanoma. Histopathology (H&E stain; 200×) correlated to the reflectance (RM; 830 nm) and fluorescence mode (FM; 488 nm) in the ex-vivo CLSM (Vivablock^® by VivaScan^® , acridine orange).

Identification of ex-vivo confocal scanning microscopic features and their histological correlates in human skin

Ex-vivo confocal laser scanning microscopy (CLSM) is an emerging diagnostic tool allowing fast and easy microscopic tissue examination. The first generation of ex-vivo devices have already shown promising results in the ex-vivo evaluation of basal cell carcinoma compared to Mohs surgery. Nevertheless, for the diagnostics of pathological skin lesions the knowledge of normal skin features is essential. Therefore we examined 50 samples of healthy skin from various donor sites including head and neck (n = 25), trunk (n = 10), upper (n = 10) and lower extremities (n = 5) using a new generation ex-vivo CLSM device offering three different laser wavelengths and compared the findings to the corresponding histological sections. In correlation with the histopathology we identified different layers of the epidermis, differentiated keratinocytes from melanocytes and described in detail skin appendages including hair follicle, sebaceous and sweat glands. Furthermore, structures of the dermis and subcutis were illustrated. Additionally, artefacts and pitfalls occurring with the use of ex-vivo CLSM have been documented. The study offers an overview of the main ex-vivo CLSM skin characteristics in comparison to the standard histological examination and helps to recognize and avoid common artefacts. Anatomy of a hair follicle in the reflectance mode (RM) CLSM, fluorescence mode (FM) CLSM and in a routine hematoxylin-eosin stained histological section (H).

[Methods for measuring skin aging]

Aging affects human skin and is becoming increasingly important with regard to medical, social and aesthetic issues. Detection of intrinsic and extrinsic components of skin aging requires reliable measurement methods. Modern techniques, e.g., based on direct imaging, spectroscopy or skin physiological measurements, provide a broad spectrum of parameters for different applications.