The measurement of photodamage

A new Chinese crow's feet grading scale based on the DermaTOP system

Many Chinese wrinkle studies continue to use non-Chinese scales because few Chinese-based wrinkle scales have been developed. The study aims to develop a crow's feet grading scale for Chinese individuals. We enrolled 608 healthy Chinese subjects and measured data through the DermaTOP system. We chose exploratory factor analysis (EFA) to reduce the dimensions of the data. A three-factor structure was obtained by using EFA, and it explained a cumulative total of 89.551% of the variance. A computational formula was obtained by calculating the total factor tilt scores and taking the variance contribution rate of three factors as the weight. Based on the computational formula, a grading map was designed and tested. The model validation was conducted using both subjective assessments from the expert panel and objective results from the model calculations. The results showed that our grading scale model is stable. This study developed a Chinese crow's feet (CCF) grading scale, which included a parameter, a grading map, and literal descriptions. The CCF grading scale is a validated tool for evaluating the effects of cosmetics or specific therapies. More importantly, the CCF scale was developed based on objective data, which may inspire new ideas for wrinkle grading scale development in the future.

Repeated exposure to fractional CO2 laser delays squamous cell carcinoma formation and prevents clinical and subclinical photodamage visualized by line-field confocal optical coherence tomography and histology

OBJECTIVES

Ablative fractional laser (AFL) is a well-established modality for treating ultraviolet radiation (UVR)-induced skin photodamage. We aimed to investigate the potential of AFL to delay squamous cell carcinoma (SCC) formation and prevent photodamage in a preclinical UVR-induced SCC model.

MATERIALS AND METHODS

Hairless C3.Cg-Hrhr /TifBomTac mice (n = 50) were exposed to UVR three times weekly throughout the study. UV-exposed mice were randomized to two groups that received dorsal CO2 AFL (10 mJ/mb, 10% density) or no treatment. AFL was performed every other week for a total of 16 weeks (nine treatments in total). The primary outcome was time to tumor occurrence. In a subset of mice on Day 150, prevention of clinical photodamage was assessed by examination of skin tightness and dyspigmentation. Concomitantly, assessment of subclinical photoprevention based on normalization of keratinocyte dysplasia, dermo-fiber morphology (collagen and elastin fibers), and skin thickness, was performed using line-field confocal optical coherence tomography (LC-OCT) and histology.

RESULTS

Repeated AFL treatments delayed SCC tumor development compared to UVR control mice by 12, 19, and 30 days for first, second, and third tumors, respectively (p ≤ 0.0017). Compared to UVR controls, AFL prevented photodamage both clinically and subclinically, based on LC-OCT and histology. In the epidermal layer, AFL imparted photopreventative effects including reduced dyspigmentation and keratinocyte dysplasia (1 vs. 2.5, p = 0.0079) and partial normalization of the epidermal thickness (p < 0.0001). In the dermis, AFL led to twofold greater skin tightness (p = 0.0079), improved dermo-fiber structure, and dermal thickness (p = 0.0011).

CONCLUSION

In conclusion, repeated AFL treatments of UVR-exposed skin significantly delayed SCC tumor formation and prevented clinical and imaging-assessed subclinical signs of photodamage, indicating a potential for AFL in prevention strategies for SCC and photodamage in high-risk populations.

Concurrent Reflectance Confocal Microscopy and Laser Doppler Flowmetry to Improve Skin Cancer Imaging: A Monte Carlo Model and Experimental Validation

Optical interrogation of suspicious skin lesions is standard care in the management of skin cancer worldwide. Morphological and functional markers of malignancy are often combined to improve expert human diagnostic power. We propose the evaluation of the combination of two independent optical biomarkers of skin tumours concurrently. The morphological modality of reflectance confocal microscopy (RCM) is combined with the functional modality of laser Doppler flowmetry, which is capable of quantifying tissue perfusion. To realize the idea, we propose laser feedback interferometry as an implementation of RCM, which is able to detect the Doppler signal in addition to the confocal reflectance signal. Based on the proposed technique, we study numerical models of skin tissue incorporating two optical biomarkers of malignancy: (i) abnormal red blood cell velocities and concentrations and (ii) anomalous optical properties manifested through tissue confocal reflectance, using Monte Carlo simulation. We also conduct a laboratory experiment on a microfluidic channel containing a dynamic turbid medium, to validate the efficacy of the technique. We quantify the performance of the technique by examining a signal to background ratio (SBR) in both the numerical and experimental models, and it is shown that both simulated and experimental SBRs improve consistently using this technique. This work indicates the feasibility of an optical instrument, which may have a role in enhanced imaging of skin malignancies.

Histopathological study of perilesional skin in patients diagnosed with nonmelanoma skin cancer

BACKGROUND

Epidemiological and clinical data suggest that actinic damage to the skin is an important predictor of skin carcinogenesis.

AIM

To investigate the association of squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) with sun-damage alterations seen by histopathology.

METHOD

In the current prospective study, perilesional skin of SCC or BCC lesions was evaluated for presence of alterations associated with chronic photodamage. Presence of scarring, perineural/perivascular invasion, haemorrhage/haemorrhagic crust, ulceration/erosion and margin involvement were also assessed.

RESULT

Of 6038 included lesions, 4523 (74.9%) were BCCs and 1515 (25.1%) were SCCs. Presence of actinic damage was five times more frequent in SCC than in BCC (OR = 5.29, 95% CI 4.44-6.00, P < 0.001), and diagnosis of SCC was twice as common in photo-exposed than nonphoto-exposed body sites (OR = 2.34, 95% CI 2.03-2.70, P < 0.001). There were twofold higher odds for actinic damage in SCC compared with Bowen disease (OR = 2.015, 95% CI 1.55-2.61, P < 0.001). Assessing the different BCC histological subtypes, we found that nodular BCC had at least twofold higher odds (OR = 2.63, 95% CI 2.09-3.32), infiltrative BCC had 48% higher odds (OR = 1.487, 95% CI 1.18-1.87) and basosquamous BCC had fourfold higher odds (OR = 4.10, 95% CI 3.01-5.57) of having actinic damage compared with superficial BCC.

CONCLUSIONS

Histological verification of ultraviolet-associated alterations in the perilesional skin in patients with NMSC in our study confirms the aetiopathogenic link between sun exposure and epithelial carcinogenesis on a histopathological basis. This correlation was stronger for SCCs than for BCCs.

Development of a photographic scale for consistency and guidance in dermatologic assessment of forearm sun damage

OBJECTIVES

To develop a photographic sun damage assessment scale for forearm skin and test its feasibility and utility for consistent classification of sun damage.

DESIGN

For a blinded comparison, 96 standardized 8 × 10 digital photographs of participants' forearms were taken. Photographs were graded by an expert dermatologist using an existing 9-category dermatologic assessment scoring scale until all categories contained photographs representative of each of 4 clinical signs. Triplicate photographs were provided in identical image sets to 5 community dermatologists for blinded rating using the dermatologic assessment scoring scale.

SETTING

Academic skin cancer prevention clinic with high-level experience in assessment of sun-damaged skin.

PARTICIPANTS

Volunteer sample including participants from screenings, chemoprevention, and/or biomarker studies.

MAIN OUTCOME MEASURES

Reproducibility and agreement of grading among dermatologists by Spearman correlation coefficient to assess the correlation of scores given for the same photograph, κ statistics for ordinal data, and variability of scoring among dermatologists, using analysis of variance models with evaluating physician and photographs as main effects and interaction effect variables to account for the difference in scoring among dermatologists.

RESULTS

Correlations (73% to >90%) between dermatologists were all statistically significant (P < .001). Scores showed good to substantial agreement but were significantly different (P < .001) for each of 4 clinical signs and the difference varied significantly (P < .001) among photographs.

CONCLUSIONS

With good to substantial agreement, we found the development of a photographic forearm sun damage assessment scale highly feasible. In view of significantly different rating scores, a photographic reference for assessment of sun damage is also necessary.

Nonablative Remodeling with a 1,540 nm Erbium:Glass Laser

BACKGROUND

Nonablative remodeling has recently been proposed as a new antiaging treatment with no downtime. This technique could greatly benefit the increasing numbers of patients who are looking for new and efficient techniques, with a minimum of discomfort.

MATERIALS

AND METHODS. The 1.54 microm wavelength has been proposed for this application because this wavelength is well absorbed by water yet virtually not at all by melanin, allowing deep penetration into the skin. To protect the epidermis during laser irradiation, a cooling system (+5 degrees C) uses a sapphire window (purified tetrafluoroethane circulates in a pipe around the sapphire) directly applied to the skin through which the laser pulse may be fired.

RESULTS

Several clinical trials have been published and have demonstrated that clinical improvement was correlated with data from ultrasound imaging, histology, and profilometry. A recent trial on the forehead and neck yielded additional data on elasticity measured by echorheometry.

CONCLUSIONS

The 1.54 microm laser is safe and effective for remodeling in all of these published studies. Remodeling requires months to achieve its goal, and the kind of improvement that can be expected should be explained to the patient. Long-term follow-up showed that the improvement increased after each treatment and lasted for months after the final session.

Life-threatening environmental dermatoses and agents of mass destruction with serious systemic consequences

The idea of this paper is to acquire a new view of some environmental conditions affecting the skin and carry with them significant morbidity. It is also to understand their etiology and nature to prevent their hazardous and serious complications which are life-threatening. Although most dermatologic disorders rarely have a fatal outcome, there are many potentially fatal medical disorders that have early or major dermatologic manifestations. Some cases lead to death because of the loss of barrier function of the epidermis with fluid and electrolyte loss or from systemic invasion of microorganisms. In others, dermatologic signs reveal an underlying systemic disease where death may occur from the underlying problem.

Skin ageing and wrinkles: clinical and photographic scoring

Sunlight induces clinical, histological and physiological changes in the skin that are known as photoageing. As the population ages, prevention and treatment of photoageing is a growing challenge because of its association with skin cancer as well as for cosmetic reasons. Therefore, it is of interest to assess the degrees of photoageing by developing valid and comprehensive grading systems. Several different methods have been proposed. These include descriptive grading scales, visual analogue scales and photographic grading scales. The merits and inconveniences of these different approaches are discussed.

Photothermal detection of laser-induced damage in single intact cells

BACKGROUND AND OBJECTIVE

Most of the studies of laser-induced damage do not analyze individual cells. Objective of this work was to evaluate local photo-induced thermal phenomena in single cells at theoretical and experimental levels for developing the method for real-time detection of laser damage in intact cells.

STUDY DESIGN/MATERIALS AND METHODS

Theoretical model of cell-laser interaction assumes local nature of photo-induced thermal effects and describes photodamage through bubble formation. Photothermal (PT) method was suggested for damage detection. Laser-induced damage was verified for individual cells with two techniques through detection of Trypan blue penetration into damaged cell.

RESULTS

Specific PT responses from blast-transformed lymphocytes were identified independently as result of bubble formation and cell damage. Probability of cell damage was obtained for cells as function of laser pulse energy.

CONCLUSIONS

The Laser load test (LLT) was suggested for real-time detection of damage, damage threshold measurement, and investigation of intact single cells.

Collagen remodeling after 585-nm pulsed dye laser irradiation: an ultrasonographic analysis

BACKGROUND AND OBJECTIVES

Nonablative dermal remodeling is an evolving technology that has generated great interest among both laser surgeons and patients. Evidence indicates that dermal collagen formation is the key mechanism of action for the nonablative techniques. We studied, with ultrasound, new collagen formation after nonablative laser irradiation.

METHODS

Ten patients with facial rhytids underwent a single treatment with a 585-nm pulsed dye laser. The patients were all female, ranging in age from 47 to 67, and were Fitzpatrick skin types I-III. Laser parameters were as follows: an energy fluence of 2.4 to 3.0 J/cm2, a pulse duration of 350 microsec, and a spot size of 5 mm with no overlap. Ultrasonographic assessments of dermal collagen were taken at baseline and at 30 and 90 days after treatment.

RESULTS

Ultrasonography demonstrated an increase in dermal collagen after a single treatment with the 585-nm pulsed dye laser. The greatest degree of neocollagenesis occurred periocularly.

CONCLUSION

A single treatment with a 585-nm pulsed dye laser appears to increase dermal collagen. This increase in dermal collagen can be assessed with noninvasive cutaneous ultrasound.

Nonablative remodeling: a 14-month clinical ultrasound imaging and profilometric evaluation of a 1540 nm Er:Glass laser

BACKGROUND

Nonablative remodeling has been recently proposed as a new antiaging treatment with no downtime.

OBJECTIVE

To evaluate the efficacy and safety of nonablative skin remodeling with a 1540 nm Er:glass laser and contact cooling on perioral and periorbital rhytides at 14 months follow-up.

METHODS

Forty-two female patients (mean age 47 years), Fitzpatrick skin types I-IV were treated five times at 6-week intervals and checked 6 months after the last treatment. Patients were evaluated using clinical data, patient satisfaction (scale 1-4), digital pictures, ultrasound imaging, and profilometry data from silicone imprints in order to quantify the degree of improvement.

RESULTS

All subjects reported an improvement in the quality and visual aspect of their skin at 6 months (mean patient satisfaction 3.06/4) and at 14 months after enrollment (mean patient satisfaction 2.90/4). This was confirmed by a 43.41% reduction of anisotropy (P < 0.001) 6 weeks after the fourth treatment, reaching 44.85% reduction 6 months after the fifth treatment (P <.001). Ultrasound imaging demonstrated a 17% increase in dermal thickness (P <.001) at 6 months and 11% 6 months after the last treatment (P <.05). A lack of immediate or late adverse effects was noted at all stages of the procedure.

CONCLUSION

This study demonstrated that irradiation with a 1540 nm Er:glass laser emitting in a pulsed mode and coupled with an efficient cooling system increased dermal thickness, reduced the anisotropy of the skin, and improved clinical aspects. The lack of adverse effects within the 14 months confirmed that this procedure was safe. Overall the stability of the results many months after the treatment was remarkable.

Objective assessment of photoageing effects using high-frequency ultrasound in PUVA-treated psoriasis patients

BACKGROUND

Skin ageing can be differentiated into intrinsic (chronological) ageing, and photoageing due to chronic sun exposure. Photoageing is the superimposition of photodamage on the ageing process.

OBJECTIVES

The aim of the study was to investigate possible differences between the skin of photochemotherapy (PUVA)-treated psoriasis patients and of untreated normal subjects using a high-frequency ultrasound system.

METHODS

A total of 124 volunteers (aged 21-88 years, median 52 years, 62 female, 62 male), 62 psoriasis patients who had received PUVA therapy and 62 healthy controls, were investigated. Skin thickness and a subepidermal low-echogenic band (SLEB), a parameter for photodamage, were measured in 12 different areas.

RESULTS

Female skin is thinner than male skin. The skin thickness values of PUVA patients were more markedly decreased than those of the controls for the older patients. There was a clear dependence of the occurrence of SLEB on PUVA therapy in psoriasis patients.

CONCLUSIONS

Long-term PUVA treatment in psoriasis patients accelerates thinning of the skin in comparison to age-matched controls. The results show that ultrasonography is a sensitive method to investigate the effects of PUVA-induced skin ageing.

Nonablative remodeling: clinical, histologic, ultrasound imaging, and profilometric evaluation of a 1540 nm Er:glass laser

BACKGROUND

Nonablative remodeling has been recently proposed as an alternative to CO2 and Er:YAG resurfacing.

OBJECTIVE

To evaluate the efficacy and safety of a 1540 nm Er:glass laser with contact cooling in nonablative skin remodeling, focused on perioral and periorbital rhytides.

METHODS

Sixty patients (mean age 47 years), Fitzpatrick skin types I-IV were treated four times over 6-week intervals. Patients were evaluated using digital photographs, histology, ultrasound imaging, and profilometry with silicone imprints in order to quantitate the degree of clinical improvement.

RESULTS

All subjects reported subjective improvement in the quality and visual aspect of their skin. This was confirmed by a 40.2% reduction of anisotropy (P <.001) 6 weeks after the fourth treatment. Ultrasound imaging demonstrated a 17% increase of dermis thickness (P <.005). Biopsy specimens showed evidence of new collagen formation.

CONCLUSION

This study has clearly demonstrated that irradiation with 1540 nm Er:glass laser can lead to new collagen formation, dermis thickening, reduction of anisotropy of the skin, and clinical improvements. The lack of adverse effects confirmed that this 1540 nm laser emitting in a pulsed mode coupled with an efficient cooling system is safe.

Endogenous skin fluorescence is a good marker for objective evaluation of comedolysis

OBJECTIVE

evaluation of comedone lesions, especially in vivo, remains a challenge. We have used the rhino mouse model in combination with topical application of all-trans retinoic acid as a comedolytic agent, to investigate the potential of fluorescence spectroscopy as a noninvasive technique in the assessment of noninflammatory acne. The results indicate that there is a strong correlation between the fluorescence excitation spectral features assessed in vivo, and the histologic changes identified, particularly the size of the utriculi as well as the dermal and epidermal thickness. We conclude that fluorescence excitation spectroscopy represents a promising novel and useful tool in the quantitative evaluation of the pseudocomedones and could also be used for the rapid and noninvasive assessment of comedolysis induced by the application of pharmacologic agents such as retinoids.

Drug treatment of photoaged skin

Although the prevention of skin aging is a holy grail of the cosmetic and pharmaceutical industries, this venture may be misplaced. The predominant clinical and biochemical features of aged skin are mostly attributable to photoaging rather than chronology. For instance chronic sun exposure is the major determinant of age spots (actinic lentigines) and wrinkles. Surgical approaches to the treatment of photoaging include face-lift, dermabrasion, chemical peeling, collagen and botulinum toxin injections, and laser re-surfacing. These approaches all have benefit and improve the clinical features of facial photoaging. Drug or pharmaceutical prevention and treatment of photoaged skin is still in its infancy. The main pharmaceutical approach to prevention of photoaging lies in the assiduous use of sunscreens. Recent evidence points to the importance of ultraviolet A (UVA) radiation as well as ultraviolet B (UVB) radiation in the aetiology of photoaging and thus the need for sunscreens that block both UVB and UVA. Drug treatment of photoaged skin can be categorised as antioxidants, alpha-hydroxy acids and topical retinoids. Of these 3 approaches only topical retinoids, particularly tretinoin (all-trans retinoic acid), have a well documented ability to repair photoaged skin at the clinical, histological and molecular level. Furthermore, the use of topical retinoids may actually prevent photoaging. The current interest in pharmaceutical modulation of the photoaging process has attracted considerable research into the mechanisms of photoaging and cutaneous aging. It is likely that treatment for, or prevention of, the chronological aging process may result from such research.

Quantitative evaluation of chronological ageing and photoageing in vivo: studies on skin echogenicity and thickness

Skin ageing is divided into chronological ageing and photoageing due to the cumulative effects of solar ultraviolet radiation. It is, however, difficult to measure the degree of photoageing and chronological ageing in humans in vivo. Here, we have evaluated the usefulness of ultrasonography for measurement of chronological ageing and photoageing in vivo. Twenty megahertz ultrasonography was performed in 90 individuals (29 men, 61 women, age 18-94) to describe age-related changes in sun-exposed regions with different levels of sun exposure (dorsal and ventral forearm, forehead, ankle) and non-exposed buttock skin. Skin thickness and skin echogenicity in different layers of the dermis were measured in ultrasound images. Additionally, cutaneous photodamage was scored clinically. Age-related changes were dependent on body site as well as layer of the dermis. A progressive, age-related decrease in echogenicity of the upper dermis was found in sun-exposed regions (dorsal forearm, forehead), but not in moderately exposed regions (ventral forearm, ankle). In the buttock an increase in echogenicity was observed. The echogenicity of the lower dermis increased in all examined sites. Skin thickness increased with age in the forehead and buttock, but decreased in the extremity skin. Our findings show that photoageing causes a decrease in echogenicity in the upper dermis. In contrast, chronological ageing is associated with an increase in echogenicity in the lower dermis. Although both increases and decreases in skin thickness were observed in different anatomical regions, there was no general relationship between skin thickness and age. Dermal echogenicity was deemed valuable for in vivo study of chronological ageing and photoageing.

Ultrasound structure and digital image analysis of the subepidermal low echogenic band in aged human skin: diurnal changes and interindividual variability

Subepidermal low-echogenic band is a consistent echostructural finding in aged and photodamaged skin. The thickness of subepidermal low-echogenic band is considered to closely reflect the degree of cutaneous aging and its use for the monitoring of the severity of photoaging and the efficacy of drugs is rapidly expanding. We investigated subepidermal low-echogenic band structure in 23 old healthy volunteers (ages 75-100) with a high-frequency ultrasound scanner (B-mode, 20 MHz). Images were collected from the volar fore-arm twice daily: in the morning before getting up and 12 h later. To assess the severity of subepidermal low-echogenic band, echogenicity of the subepidermal region was determined by the image analysis and compared with visual scoring and subepidermal low-echogenic band thickness. All three methods gave consistent results, image analysis being the most sensitive, reliable, and bias-free. Significant interindividual variability of subepidermal low-echogenic band echostructure was revealed. Moreover, circadian variability of subepidermal low-echogenic band echogenicity was observed. These major interindividual and diurnal variations of subepidermal low-echogenic band suggest that this band does not only represent an irreversible structural change but also a redistribution of fluid in the aged dermis. Diurnal variations in the subepidermal low-echogenic band would limit the use of this parameter in studies of skin aging, photoaging, and efficiency of medication.

The clinical identification and quantification of photodamage

The distinction between intrinsic and extrinsic ageing can be made on both histological and clinical grounds. Clinical criteria associated with the diagnosis of extrinsic ageing are coarse wrinkles, actinic lentigines, elastotic conditions, purpura, telangiectasia and cutaneous neoplasms. These parameters are always superimposed on changes associated with intrinsic ageing: namely, fine wrinkles and benign growths. There is heightened interest in extrinsic ageing as a result of studies demonstrating the efficacy of topical tretinoin in improving this condition. As a consequence, systems for grading extrinsic ageing have been developed, including a photographic standard scale which removes some of the subjectivity inherent to current methodology.