A noninvasive technique, reflectance confocal microscopy, for the characterization of melanocyte loss in untreated and treated vitiligo lesions

Feasibility of High-Cellular-Resolution Full-Field, Artificial-Intelligence-Assisted, Real-Time Optical Coherence Tomography in the Evaluation of Vitiligo: A Prospective Longitudinal Follow-Up Study

Vitiligo, a psychologically distressing pigmentary disorder characterized by white depigmented patches due to melanocyte loss, necessitates non-invasive tools for early detection and treatment response monitoring. High-cellular-resolution full-field optical coherence tomography (CRFF-OCT) is emerging in pigmentary disorder assessment, but its applicability in vitiligo repigmentation after tissue grafting remains unexplored. To investigate the feasibility of CRFF-OCT for evaluating vitiligo lesions following tissue grafting, our investigation involved ten vitiligo patients who underwent suction blister epidermal grafting and laser ablation at a tertiary center between 2021 and 2022. Over a six-month period, clinical features, dermoscopy, and photography data were recorded. Utilizing CRFF-OCT along with artificial intelligence (AI) applications, repigmentation features were captured and analyzed. The CRFF-OCT analysis revealed a distinct dark band in vitiligo lesion skin, indicating melanin loss. Grafted areas exhibited melanocytes with dendrites around the epidermal-dermal junction and hair follicles. CRFF-OCT demonstrated its efficacy in the early detection of melanocyte recovery and accurate melanin quantification. This study introduces CRFF-OCT as a real-time, non-invasive, and in vivo evaluation tool for assessing vitiligo repigmentation, offering valuable insights into pigmentary disorders and treatment responses.

In-depth study of Wood's lamp examination combined with reflective confocal laser scanning microscopy for the guidance of vitiligo staging and treatment

BACKGROUND

Both Wood's lamp and reflective confidential laser scanning microcopy are helpful for the diagnosis and treatment of vitiligo. However, there is few research that contains large samples and consistent observations.

AIMS

To analyze the characteristics of Wood's lamp images and reflectance confocal microscopy (RCM) images of vitiligo lesions and to evaluate their significance in vitiligo staging.

METHODS

We analyzed the characteristics of RCM images, Wood's lamp images, the vitiligo disease activity (VIDA) score, and clinical features to guide vitiligo staging and treatment.

RESULTS

The expert consensus based on the clinical features, VIDA score, Wood's lamp findings, and isomorphic response was consistent with the Wood's lamp findings (χ2  = 3.63, p > 0.05) and RCM findings (χ2  = 3.60, p > 0.05) in diagnosing vitiligo and assessing the disease stage. There was a correlation between the three lesion grades based on the Wood's lamp findings and the stage of vitiligo (p < 0.01). Lesions that appeared porcelain white under the Wood's lamp were in the slowly progressive stage; lesions that appeared gray-white or trichromatic under the Wood's lamp were in the rapidly progressive stage; lesions with clear borders under the Wood's lamp needed further analysis by RCM for the stage to be determined; lesions with blurred borders under the Wood's lamp were in the rapidly progressive stage; lesions that were visible under the naked eye and under the Wood's lamp were in the rapidly progressive stage.

CONCLUSION

The study demonstrates a reliable correlation between the findings of RCM (a sophisticated expensive tool) and Wood's lamp examination (a simple, readily available, inexpensive tool) in the assessment of the disease activity of vitiligo lesions.

Dermatoscopic Patterns in Vitiligo

Vitiligo is a chronic, acquired autoimmune pigmentary skin disease, most times it can be diagnosed clinically. Dermoscopy can confirm vitiligo in a non-invasive way. It is a diagnostic technique that visualizes sub-macroscopic morphological structures which correspond with specific histological structures. It detects subtle changes in the pigment pattern, evaluates vitiligo activity, attempts of re-pigmentation, leucotrichia, and differentiates it from other hypo pigmentary disorders. Most dermatoscopic clues used to assess vitiligo activity are found at the perifollicular level in the center and edge of the lesion. Perifollicular pigmentation is present in both active lesions and treated pigmented lesions with treatment. However, perifollicular depigmentation represents poor response, in treated lesions, and poor prognosis in untreated ones. The center of the lesion has reduced and/or absent pigment network, in active and stable lesions. If on dermoscopy the center of the lesion shows islands of pigment, erythema, or telangiectasias, re-pigmentation is suggested. At the periphery of the lesion, unstable vitiligo usually shows up as a diffuse border, trichrome pattern, micro-Koebner/comet tail phenomenon, satellite lesions, or a tapioca sago pattern. In stable lesions it is more frequent to find well defined or trichromic border. Pigmented lesions commonly present sharp borders and marginal or perilesional hyperpigmentation.

A prospective observational study to sequentially determine the dermoscopic features of vitiligo and its association with disease activity in patients on medical treatment: Dermoscopy and disease activity in vitiligo

Prospective data on correlation between dermoscopic features of vitiligo and disease activity are scarce. This study was conducted to sequentially determine the dermoscopic features of vitiligo and to evaluate their association with disease activity. A cohort of 30 patients with 60 active vitiligo patches on medical therapy was subjected to sequential clinical and dermoscopic examination at four weekly intervals till 16 weeks. Disease activity at each visit was assessed using serial clinical photographs and modified vitiligo activity severity index. The dermoscopic images were merged and analysed for a predefined set of dermoscopic parameters by two blinded dermatologists. Paired analysis of dermoscopic features was done between baseline, and stabilized vitiligo patches at 12 and 16 weeks. Pigment network changes (absent and reduced pigment network, p < .001), perifollicular depigmentation (p = .02), ill-defined margins (p = .04) and satellite lesions and micro-Koebner phenomenon (p < .001) were associated with active vitiligo while perifollicular repigmentation (p < .001) was associated with stabilizing and repigmenting vitiligo. Satellite lesions and micro-Koebner's phenomena were suggestive of unstable disease irrespective of site of target lesion, while perifollicular repigmentation was suggestive of stabilized/repigmenting disease only at non-acral sites. We found sequential dermoscopy to be useful to assess disease activity and potential for repigmentation in localized vitiligo.

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.

Utility of dermoscopy for evaluating the therapeutic efficacy of tacrolimus ointment plus 308-nm excimer laser combination therapy in localized vitiligo patients

The aim of the present study was to assess the function of dermoscopy in evaluating the therapeutic efficacy of tacrolimus ointment plus 308-nm excimer laser combination therapy in patients with localized vitiligo. A total of 147 patients with localized vitiligo (progressive disease, n=92; stable period, n=55) were enrolled and received combination therapy for 12 weeks. The condition of the skin lesions was monitored by dermoscopy and visual observation. At the initial visit, skin lesions were observed in 61 progressive and 19 stable patients. Residual perifollicular pigmentation was more abundant in progressive-stage patients than in stable-stage patients, whereas the presence of perilesional hyperpigmentation was obviously lower in patients with progressive vitiligo. After 12 weeks of combination therapy, marked differences in residual perifollicular pigmentation were identified between the progressive- and stable-stage patients. Dermoscopy and visual observation indicated that the 12-week treatment efficacy in patients with progressive disease was significantly higher than in those with stable disease and that assessment by dermoscopy was superior to visual observation at 8 or 12 weeks of treatment. Binary logistic regression analysis revealed that the disease stage, vitiliginous areas and disease course were risk factors associated with the treatment efficacy of the combination therapy. In conclusion, dermoscopy may be used as an effective means of vitiligo therapy assessment to provide an accurate and scientific evaluation of treatment efficacy for localized vitiligo patients.

Skin healing and collagen changes of rats after fractional erbium:yttrium aluminum garnet laser: observation by reflectance confocal microscopy with confirmed histological evidence

The fractional erbium:yttrium aluminum garnet (Er:YAG) laser is widely applied. Microstructural changes after laser treatment have been observed with histopathology. Epidermal and dermal microstructures have also been analyzed using reflectance confocal microscopy (RCM). However, no studies have compared these two types of microstructural changes in the same subject at multiple time points after irradiation, and it is unclear if these two types of changes are consistent. We use RCM to observe the effect of different laser energies on skin healing and collagen changes in the skin of Sprague-Dawley rats that had been irradiated by fractional Er:YAG lasering at different energies. RCM was used to observe skin healing and detect collagen changes at different time points. Collagen changes were observed using hematoxylin and eosin (H&E) staining and quantitatively analyzed by western blot. RCM showed that, irrespective of laser energy, microscopic treatment zones (MTZs) were larger at 1 day after irradiation. The MTZs then reduced in size from 3 to 7 days after irradiation. The higher the energy, the larger the MTZ area. The amount of collagen also increased with time from 1 day to 8 weeks. However, the increase in the collagen amount on both RCM and H&E staining was not influenced by the laser energy. Western blotting confirmed that the amount of type I and type III collagens increased over time, but there were no significant differences between the different energy groups (p > 0.05). In conclusion, RCM is a reliable technique for observing and evaluating skin healing and collagen expression after laser irradiation.

Quantitative method for measuring therapeutic efficacy of the 308 nm excimer laser for vitiligo

BACKGROUND

There are several available treatments for vitiligo, but measurement of their therapeutic efficacy is not standardized and is somewhat arbitrary based largely on the global impression of the overall response. The purpose of this study was to develop a quantitative method for evaluating the treatment response of vitiligo measuring changes in area using digital image analysis. We applied this parametric model to the evaluation of efficacy of the 308 nm excimer laser.

METHODS

This study was a retrospective study, designed as a before and after trial with a single arm. A total of 18 patients were enrolled who had been treated with a 308 nm excimer laser as monotherapy twice a week for 20 sessions. The repigmentation percentage was calculated by measuring changes in area before and after treatment using digital image analysis and graded on a five-point ordinal scale [global assessment scale (GAS)]. GAS was also measured by physician and patient for comparison with our estimates. Additional GASs were also measured by four different evaluators for inter-rater variability.

RESULTS

The mean repigmentation percentage after treatment was 45.3% (range, 0.7-100%). The changes in area after treatment were statistically significant (P < 0.05). A substantial agreement of outcomes was observed between physicians and digital image analysis (κ(w) = 0.78), but lower agreement was observed between patients and digital image analysis (κ(w) = 0.49). The inter-rater variability for GAS was substantially low (Krippendorff's α = 79.3%).

CONCLUSION

Measurement of changes in area using digital image analysis could be used as a quantitative method in evaluating efficacy of treatment for vitiligo. Because vitiligo lesions can occur in any location with various shapes and sizes, digital image analysis would be a more objective method for measuring treatment response than a GAS.