Transfersomal eosin topical delivery assisted by fractional CO2 laser for photodynamic treatment of palmar hyperhidrosis: case study

Hyperhidrosis is a condition in which the cholinergic receptors on the eccrine glands are overstimulated, resulting in excessive sweating. It is considered a serious cosmetic and psychological problem that affects the patient's quality of life. Searching for novel treatment modalities is required to minimize the side effects and to attain better patient satisfaction.Photodynamic therapy (PDT), using eosin as a photosensitizer, is developed as a promising modality of the treatment of palmar and axillary hyperhidrosis. In this study, we treated six cases suffering palmar hyperhidrosis by applying the fractional CO₂ laser prior to PDT session. For PDT, a hydrogel of eosin loaded in a transfersomes as a nano-delivery carrier was applied for 5 min, followed by irradiation by intense pulsed light (IPL). The prepared transfersomes loaded by eosin were spherical in shape with encapsulation efficiency of 33 ± 3.5%, particle size 305.5 ± 5.7 nm, average zeta potential of - 54 ± 7.6 mV with 80 ± 4% of the loaded eosin was released after 3 h. Two cases achieved 90% improvement after four sessions, three patients needed six sessions to show 75% improvement, while one patient showed only 25% improvement after six sessions. This resulted in shortening the time of PS application and decreasing the number of sessions required to achieve acceptable improvement. More clinical studies on large number of patients are required to optimize the results.

Efficacy and safety of combined fractional ablative CO2 laser and 5 fluorouracil in the treatment of acral vitiligo: An open, uncontrolled study

BACKGROUND

Acral lesions of vitiligo are most likely recalcitrant to the known lines of treatment. Ablative fractional CO₂ has shown efficacy in treatment of vitiligo in combination with other modalities.

METHODS

Thirty non-segmental vitiligo patients with acral lesion were included in the study. Each patient was subjected to fractional Carbon Dioxide Laser Treatment followed by application of 5 fluorouracil (5FU) cream for five consecutive days. Evaluation was done 3 weeks from the start of treatment and 12 weeks after the last treatment session using VESTA score, evaluation of patients' photos by blinded investigation in addition to patients' satisfaction scores.

RESULTS

Patients showed significant improvement of Vitiligo extent score for a target area (VESTA) score and developed considerable degree of repigmentation as assessed by blinded investigators.

CONCLUSION

The combination of fractional ablative CO₂ and 5FU is an effective and safe procedure for the treatment of acral vitiligo with promising results offering patients a new therapeutic window.

Ablative Fractional Laser-assisted Low-irradiance Photodynamic Therapy for Treatment of Actinic Keratoses in Organ Transplant Recipients: A Prospective, Randomized, Intraindividual Controlled Trial

Pain and inferior efficacy are major limiting factors of conventional photodynamic therapy for the field treatment of actinic keratoses in immunosuppressed organ transplant recipients. This prospective randomized controlled study evaluates the efficacy and tolerability of ablative fractional laser system pretreatment combined with low-irradiance photodynamic therapy (18.5 mW/cm2) compared with conventional photodynamic therapy (61.67 mW/cm2) in the treatment of actinic keratoses on the face and scalp in organ transplant recipients, using a red light-emitting diode lamp at a total light dose of 37 J/cm2. Low-irradiance photodynamic therapy combined with Er:YAG pretreatment achieved a significantly superior lesion response rate (mean ± standard deviation 77.3 ± 23.6%) compared with conventional photodynamic therapy (61.8 ± 21.4%; p = 0.025) in intra-individual fields at 3 months without negatively impacting pain (p = 0.777) or cosmetic outcome (p = 0.157).

Management of oral leukoplakia by ablative fractional laser‐assisted photodynamic therapy: A 3‐year retrospective study of 48 patients

Objectives

This study aimed to review the results of oral leucoplakia (OL) using ablative fractional laser‐assisted photodynamic therapy (AFL‐PDT) and to further evaluate the risk factors for recurrence and malignant transformation.

Materials and Methods

Forty‐eight patients diagnosed with OL using histopathology were enrolled in this study. All patients received one session of AFL‐PDT. Therapeutic efficacy was evaluated 1 month posttreatment. Follow‐up was scheduled every 3 months in the first year and every 6 months thereafter.

Results

An overall positive response rate of 87.5% (42/48) was achieved, including 62.5% (30/48) complete responses and 25.0% (12/48) partial responses. During the 3‐year follow‐up period, the recurrence and malignant transformation rates were 37.5% (18/48) and 8.3% (4/48), respectively. Lesions on gingiva/palate seemed to be associated with recurrence (p < 0.001; odds ratio [OR]: 1.64, 95% confidence interval [CI]: 1.13–2.37). The severity of epithelial dysplasia (p = 0.02; OR: 2.93, 95% CI: 1.96–4.42) and recurrence (p = 0.016; OR: 3.14, 95% CI: 2.04–4.84) were associated with a predisposition to malignant transformation.

Conclusions

AFL‐PDT is an effective management of OL, but requires close follow‐up. OL lesions on the gingiva/palate are predisposed to recurrence. OLs that recur with moderate/severe epithelial dysplasia have a higher risk of transforming into oral squamous cell carcinoma.

The combination of photodynamic therapy and fractional CO2 laser for mycobacterium marinum infection

Mycobacterium marinum (M. marinum) can cause cutaneous infection. Therapy with active antibiotics for 3 to 6 months is one reasonable treatment. However, it is hard to provide an optimal balance with regard to efficacy and tolerability when the patient is complicated with other diseases. We reported two patients with cutaneous M. marinum infections who were successfully treated with 5-aminolevulinic acid-photodynamic therapy (5-ALA-PDT) combined with fractional CO2 laser ablation. The results of these two cases indicated that PDT in combination with fractional CO2 laser ablation of epidermis could be a therapeutic option for the treatment of skin infections caused by M. marinum.

Micro- and Nano-Based Transdermal Delivery Systems of Photosensitizing Drugs for the Treatment of Cutaneous Malignancies

Photodynamic therapy is one of the more unique cancer treatment options available in today’s arsenal against this devastating disease. It has historically been explored in cutaneous lesions due to the possibility of focal/specific effects and minimization of adverse events. Advances in drug delivery have mostly been based on biomaterials, such as liposomal and hybrid lipoidal vesicles, nanoemulsions, microneedling, and laser-assisted photosensitizer delivery systems. This review summarizes the most promising approaches to enhancing the photosensitizers’ transdermal delivery efficacy for the photodynamic treatment for cutaneous pre-cancerous lesions and skin cancers. Additionally, discussions on strategies and advantages in these approaches, as well as summarized challenges, perspectives, and translational potential for future applications, will be discussed.

Pretreatment with ablative fractional carbon dioxide laser improves treatment efficacy in a synergistic PDT protocol for actinic keratoses on the head

BACKGROUND

A recently proposed synergistic photodynamic therapy protocol (s-PDT) combining advantages of both conventional- and daylight-PDT proved to be an effective and almost painless treatment for patients with actinic keratoses (AKs). This study investigated the safety and efficacy of an additional ablative fractional CO2-laser (AFXL) pretreatment.

METHODS

28 patients with AKs on the head received s-PDT using 5-aminolevulinic acid. AFXL pretreatment was conducted using the following parameters: pulse energy 8 mJ, spot density 50 spots/cm², power 30 W, beam size 4-18 mm. Outcome was assessed by AK area and severity index (AKASI) and lesion count (LC) before and 3 months after treatment. Safety was monitored by blood pressure and pulse measurements. Intensity of pain was determined by use of a visual analog scale (VAS).

RESULTS

Most patients (96.4 %) showed a significant AKASI reduction (P < 0.0001) 3 months after PDT (median AKASI 1.6 [0-2.4]) compared to baseline (5.3 [4-7.75]). Median reduction rate was 75.5 % (61.3 %-100 %). Eleven patients (39.3 %) achieved AKASI 100, three (10.7 %) AKASI 75 and ten (35.7 %) AKASI 50. Blood pressure and pulse did not change significantly throughout treatment. Median VAS for pain during irradiation was 0 (0-0), 0 (0-2) and 0 (0-2) at the beginning, in the meantime and at the end, respectively. Compared to data without AFXL pretreatment, this study showed significantly higher AKASI and LC reduction rates (75.5 % vs. 63.7 % [P = 0.023] and 91.3 % vs. 80.4 % [P = 0.043]).

CONCLUSIONS

S-PDT with AFXL pretreatment represents a safe and almost painless treatment for patients with AKs on the head and improves treatment efficacy.

Combination of Laser Therapy and Photodynamic Therapy with 5-Aminolevulinic Acid Patch for the Treatment of Actinic Cheilitis

Background: Actinic cheilitis (AC) is a premalignant lesion of the lips that can evolve into squamous cell carcinoma. Among nonsurgical treatments, photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA) patch might represent a new noninvasive therapeutic approach for AC. Objective: We sought to investigate the potential role of fractional CO₂ laser pretreatment in boosting ALA penetration and distribution into AC treated with PDT. Methods: We report a case of a woman with AC on the lower lip, treated with ablative fractional CO₂ laser to boost drug delivery of 5-ALA patch before PDT treatment. Reflectance confocal microscopy was performed to assess diagnosis and treatment response. Results: We detected a good clinical and cosmetic outcome after two applications of combined treatment. Erythema, crust, and edema were reported as side effects. Conclusions: This case report shows that ablative fractional CO₂ laser-assisted PDT might be an effective therapeutic alternative for patients with AC who refuse or are contraindicated for surgical procedures.

Successful treatment of primary cutaneous localized amyloidosis with a combined therapy of ablative fractionated CO2 laser, topical retinoid, corticosteroids and levovitamin C: Five cases with two-year follow-up

Primary cutaneous localized amyloidosis (PCLA) is a pruritic disorder with no radical cure. We trialed a combined therapy of ablative fractionated CO2 laser, topical retinoid, corticosteroids and levovitamin C on five patients. All patients responded with no intolerant signs. Two-year follow-up visit showed no recurrence. This might be a effective method awaiting more samples for further stronger evidence.

The application of physical pretreatment in photodynamic therapy for skin diseases

Photodynamic therapy (PDT) is widely used in skin diseases; the response rate of PDT treatment varies widely. The limited penetration in the tissue of photosensitizers influenced the penetration depth of PDT, which obviously impacts the therapeutic effect. The studies have improved the efficacy of PDT through various pretreatment applications; especially, the physical pretreatment had achieved significant outcomes. We will review the physical pretreatment to optimize the efficacy of PDT in skin diseases by searching the literature on this topic. The types of physical pretreatment commonly used in the clinical practice are discussed: curettage, superficial shaving, laser, surgical resection, plum-blossom needles, and microneedles. Compared with PDT alone, the physical pretreatment before PDT application was generally improved the efficacy and reduced the recurrence, especially in actinic keratoses (AK), Bowen disease (BD), basal cell carcinoma (BCC), and viral warts. The application of the physical pretreatments before PDT may improve the efficacy of PDT in various skin diseases. However, each kind of physical pretreatment has the benefit and shortcoming, and the applicable situation is different.

Update Dermatologische Lasertherapie II – Weiterentwicklung der photodynamischen Therapie durch Laser‐assistierte transkutane Applikation von Topika

Die technische Fortentwicklung der jüngeren Vergangenheit bietet dem Dermatologen Zugriff auf neue Laser, Strahlquellen und Behandlungskonzepte. Seit langem eingeführte Wellenlängen zur Ablation sind nunmehr fraktioniert applizierend verfügbar und stehen nunmehr für eine wirksamere und effizientere Behandlung von zahlreichen Hautveränderungen zur Verfügung. Das gezielte Einbringung von Topika (laser assisted drug delivery; LADD) ist das wichtigste Beispiel. Die LADD erfordert eine spezifische Weiterbildung, um sicher und wirksam zur Therapie (prä-)maligner nichtmelanozytärer Neoplasien der Haut wie der Feldkanzerisierung in Form der Laser-assistierten photodynamischen Therapie angewandt werden zu können. Bisher verfügbare Daten weisen auf eine höhere Effektivität im Vergleich zu konventionell verwendeten Topika hin, wobei anhaltend über Weiterentwicklungen berichtet wird. Unter anderem wurde die Kombination mit Tageslicht oder alternativen tageslichtähnlichen Strahlquellen bekannt. Dieses Update basiert wie zitiert gekürzt und aktualisiert auf "Paasch, U. 2019. Laser-assistierte photodynamische Therapie. p. 226-239. In G. Kautz (ed.) Energie für die Haut. Springer Nature, Springer Nature.".

Update on dermatologic laser therapy II - advances in photodynamic therapy using laser-assisted drug delivery

Technical advances in recent years have led to the development of new dermatologic laser systems, light sources, and treatment concepts. With the introduction of ablative fractional lasers (using common wavelengths) in the field of dermatology, it is now possible to more effectively and efficiently treat a variety of skin disorders. One important example of these advances is laser-assisted drug delivery (LADD). A type of LADD, laser-assisted photodynamic therapy has been successfully employed in the treatment of non-melanoma skin cancer including field cancerization. This treatment concept has been continually modified and today includes the use of daylight as well as artificial daylight systems. This update is based as cited, shortened and updated according to "Paasch,U. 2019. Laser-assistierte photodynamische Therapie. p. 226-239. In G.Kautz (ed.) Energie für die Haut. Springer Nature, Springer Nature".

Development of a Predictive Monte Carlo Radiative Transfer Model for Ablative Fractional Skin Lasers

It is possible to enhance topical drug delivery by pretreatment of the skin with ablative fractional lasers (AFLs). However, the parameters to use for a given AFL to achieve the desired depth of ablation or the desired therapeutic or cosmetic outcome are hard to predict. This leaves open the real possibility of overapplication or underapplication of laser energy to the skin. In this study, we developed a numerical model consisting of a Monte Carlo radiative transfer (MCRT) code coupled to a heat transfer and tissue damage algorithm. The simulation is designed to predict the depth effects of AFL on the skin, verified with in vitro experiments in porcine skin via optical coherence tomography (OCT) imaging. Ex vivo porcine skin is irradiated with increasing energies (50-400 mJ/pixel) from a CO₂ AFL. The depth of microscopic treatment zones is measured and compared with our numerical model. The data from the OCT images and MCRT model complement each other well. Nonablative thermal effects on surrounding tissue are also discussed. This model, therefore, provides an initial step toward a predictive determination of the effects of AFL on the skin. Lasers Surg. Med. © 2020 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals LLC.

Comparison of Grenz ray and photodynamic therapy for field treatment of actinic keratoses on the forearm: A case series

BACKGROUND

Actinic Keratosis is an intraepidermal neoplasm that represents the second most common reason for dermatologic visits in the United States. Sustained clearance with existing therapies is highly variable.

OBJECTIVE

To assess the effects of combination and monotherapy with photodynamic therapy (PDT), grenz ray therapy, and PDT with microneedling (microchannel skin system) for actinic damage of the dorsal forearms and hands.

METHODS

Full ethics approval was obtained through a Human Subjects Committee. Four patients with diffuse actinic field damage on their forearms and hands were recruited for the study. The dorsal forearm and hand from the elbow to the metacarpophalangeal joint were divided into four equal sections. Section 1 was treated with PDT. Section 2 was treated with grenz ray. Section 3 was treated with PDT plus microneedling. Section 4 was treated with grenz ray and PDT with microneedling. Lesion counts were recorded with transparent grids, photographed and evaluated by the same investigator at baseline, 1, 2, 3 and 6 months.

RESULTS

At month 6 post treatment, lesion counts, as a per cent reduction from baseline, were 91.7% in section 1 (PDT); 97.3% in section 2 (grenz ray); 92.9% in section 3 (PDT + microneedle); and 93.9% in section 4 (grenz ray + PDT + microneedle).

CONCLUSION

The greatest reduction occurred in the grenz ray monotherapy section and the second greatest reduction in the grenz ray, PDT, microneedling section. Further research on the efficacy of grenz ray therapy for field treatment of actinic keratosis of the forearms and hands is needed.

Thermo-Mechanical Fractional Injury Enhances Skin Surface- and Epidermis- Protoporphyrin IX Fluorescence: Comparison of 5-Aminolevulinic Acid in Cream and Gel Vehicles

BACKGROUND AND OBJECTIVES

Thermo-mechanical fractional injury (TMFI) impacts the skin barrier and may increase cutaneous drug uptake. This study investigated the potential of TMFI in combination with 5-aminolevulinic acid (ALA) cream and gel formulations to enhance Protoporphyrin IX (PpIX) fluorescence at the skin surface and in the skin.

STUDY DESIGN/MATERIALS AND METHODS

In healthy volunteers (n = 12) a total of 144 test areas were demarcated on the upper back. Test areas were randomized to (i) TMFI (6 milliseconds, 400 µm at a single pass) or no pretreatment and (ii) 20% ALA in cream or gel formulations. Skin surface PpIX fluorescence was quantified by PpIX fluorescence photography and photometry in 30-minute intervals until 3 hours. PpIX fluorescence microscopy quantified separate PpIX fluorescence in the epidermis, and in superficial-, mid-, and deep- dermis from punch biopsies sampled after 3 hours of ALA incubation. Local skin reactions (LSR) and pain intensities (numerical rating scale 0-10) were evaluated immediately, at 3 hours and 14 days after the intervention.

RESULTS

TMFI exposure before photosensitizer application significantly increased skin surface PpIX fluorescence, both for ALA cream (TMFI-ALA-cream 7848 arbitrary units [AU] vs. ALA-cream 5441 AU, 3 hours, P < 0.001) and ALA gel (TMFI + ALA-gel 4591 AU vs. ALA-gel 3723 AU, 3 hours, P < 0.001). The TMFI-mediated increase in PpIX fluorescence was similar for ALA-cream and -gel formulations (P = 0.470) at the skin surface. In the epidermis, PpIX fluorescence intensities increased from combination treatment with TMFI and ALA-cream (TMFI + ALA-cream 421 AU vs. ALA-cream 293 AU, P = 0.034) but not from combination with TMFI and ALA-gel (TMI + ALA-gel 264 AU vs. ALA-gel 261 AU, P = 0.791). Dermal fluorescence intensities (superficial-, mid-, or deep dermis) were unaffected by TMFI pretreatment in both ALA-cream and ALA-gel exposed skin (P = 0.339). ALA-cream generally induced higher PpIX fluorescence intensities than ALA-gel (skin surface P < 0.001 and epidermis P < 0.03). TMFI induced low pain intensities (median 3) and mild LSR that were resolved at 14 days follow-up.

CONCLUSION

Given the present study design, TMFI, in combination with the standardized application of 20% ALA cream and gel formulations, significantly enhanced skin surface PpIX fluorescence compared to no pretreatment. Additionally, TMFI increased epidermal PpIX fluorescence combined with 20% ALA cream vehicle. Thus, TMFI pretreatment and formulation characteristics exert influence on PpIX fluorescence intensities in normal skin. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Factors Affecting Depth of Penetration in Microneedling- and Laser-Assisted Drug Delivery: The Importance of Timing of Topical Application

BACKGROUND

Microneedling- and laser-assisted drug delivery are emerging techniques used to treat various conditions. However, key parameters affecting drug penetration remain unknown.

OBJECTIVE

This study aims to investigate the importance of timing of topical application, needle length, and device type for drug delivery.

MATERIALS AND METHODS

Skin harvested from cosmetic surgeries was treated with black ink applied before or after treatment with a microneedling pen (MP), roller, or fractional ablative CO2 laser, and incubated for different time intervals. Ink penetration was additionally tested using different needle lengths. Sandwich estimator was used for statistical analysis.

RESULTS

Ink applied before MP penetrated deeper compared to ink applied afterward at 1 and 3 hours, and roller microneedling in both the ink-before and -after scenarios at 1, 3, and 6 hours (p < .05). Microneedling demonstrated lateral extension of ink beyond microchannels with increased ink penetration over time. CO2 laser demonstrated ink localization within microthermal zones without time-dependent increases in depth after 30 minutes. Ink penetration increases by 0.06 mm per 1 mm increase in needle length.

CONCLUSION

Ink applied before MP results in the deepest penetration of ink. Microneedling offers unique advantages in transdermal delivery as its channels exhibit increasing penetration over time and lateral extension of product.

Fundamentals of fractional laser-assisted drug delivery: An in-depth guide to experimental methodology and data interpretation

In the decade since their advent, ablative fractional lasers have emerged as powerful tools to enhance drug delivery to and through the skin. Effective and highly customizable, laser-assisted drug delivery (LADD) has led to improved therapeutic outcomes for several medical indications. However, for LADD to reach maturity as a standard treatment technique, a greater appreciation of its underlying science is needed. This work aims to provide an in-depth guide to the technology's fundamental principles, experimental methodology and unique aspects of LADD data interpretation. We show that drug's physicochemical properties including solubility, molecular weight and tissue binding behavior, are crucial determinants of how laser channel morphology influences topical delivery. Furthermore, we identify strengths and limitations of experimental models and drug detection techniques, interrogating the usefulness of in vitro data in predicting LADD in vivo. By compiling insights from over 75 studies, we ultimately devise an approach for intelligent application of LADD, supporting its implementation in the clinical setting.

Ablative fractional laser-assisted treatments for keratinocyte carcinomas and its precursors-Clinical review and future perspectives

Keratinocyte carcinomas (KC) are the most common malignant human neoplasms. Although surgery and destructive approaches are first-line treatments, topical therapies are commonly used. Due to limited uptake of topical agents across the skin barrier, clearance rates are often sub-optimal. In pre-clinical investigations, ablative fractional laser (AFL)-assisted drug delivery has demonstrated improved uptake of topical drugs commonly used to treat KC. In 22 clinical trials, the effect of AFL-assisted treatments has been investigated for actinic keratosis (AK; n = 14), Bowen's disease (BD; n = 5), squamous cell carcinoma (n = 1), and basal cell carcinoma (n = 7). The most substantial evidence currently exists for AFL-assisted photodynamic therapy for the treatment of AK and BD. AFL improved 12-months follow-up clearance rates of photodynamic therapy from 45.0-51.0% to 78.5-84.8% for AK and from 50.0-55.3% to 87.0-87.5% for BD. AFL-assisted pharmacological therapy is a promising tool for optimizing topical treatments of KC and its precursor lesions. Future developments include AFL-assisted immune activation, changing drug administration route of systemic therapies, and utilizing drug chemo-combinations.

Laser-Assisted Delivery to Treat Facial Scars

Treatment of facial scars is a multispecialty endeavor for optimal patient recovery. One new innovation helping in facial scar treatments are lasers. Fractional laser predictably (tunable) disrupts the barrier of the skin creating deep channels that allow the delivery of drug and cellular materials; this is called laser-assisted drug delivery (LAD). Without exception thus far, LAD has been found to enhance the local uptake of any drug or substance applied to the skin. These zones may be used postoperatively to deliver drugs and other substances to create an enhanced scar therapeutic response to drug or substance applied to the skin.

Fractional Laser-Assisted Topical Imiquimod 5% Cream Treatment for Recalcitrant Common Warts in Children: A Pilot Study

BACKGROUND

Conventional treatments for warts like cryotherapy are limited by the pain during procedures, especially in pediatric patients. Imiquimod is a topical immune response modifier, but the thick stratum corneum of common warts prevents drug permeation through skin.

OBJECTIVE

To evaluate the efficacy and safety of fractional laser/topical 5% imiquimod cream for the treatment of warts in children.

METHODS

Eleven pediatric patients with multiple recalcitrant common warts were included. Lesions were treated using an ablative fractional 2,940-nm Er:YAG laser at 1- or 2-week interval. After each laser treatment session, imiquimod 5% cream was self-applied once daily 5 days a week. Response and adverse effects were assessed 2 weekly until complete clearance or up to maximum of 48 weeks. Pain during fractional laser was assessed using a visual analogue scale (0-10).

RESULTS

Eight of the 11 (72.7%) children experienced complete clearance. Mean duration was 29.7 (16-48) weeks, and the mean number of fractional laser was 17.5 (8-37). No significant adverse effect was observed. Pain visual analogue scale during fractional laser was 2.4 (1-4) compared to 6.2 (5-8) during cryotherapy.

CONCLUSION

This pilot study indicates that fractional laser-assisted topical imiquimod may provide benefit for recalcitrant warts in children.

Multiple sequential light and laser sources to activate aminolevulinic acid in the treatment of photodamage: A retrospective study

INTRODUCTION

The aim of this study was to retrospectively evaluate photodynamic therapy (PDT) with aminolevulinic acid (ALA) for cutaneous photorejuvenation using blue light sequentially with red light, pulsed-dye laser (PDL), and/or intense pulsed light (IPL).

MATERIALS AND METHODS

Ninety-six patients (121 treatments) had photodamage treated with field-directed ALA-PDT from 2001 to 2010 in this single-center study. Treatments were performed with blue light + PDL, blue light + IPL, blue light + PDL + IPL, or blue light + red light + PDL + IPL. Outcome measures were obtained via telephone questionnaire and graded on a four-point scale.

RESULTS

There were no significant differences in patient-reported improvement in photodamage, overall skin quality, and postprocedure adverse events between treatment arms. However, number of patients in the blue light + red light + PDL + IPL group was markedly smaller (n = 2) than that in the other groups (n = 14-46).

DISCUSSION

Although results showed a trend toward greater efficacy with similar tolerability using multiple, sequential light and laser sources with ALA-PDT for photorejuvenation, the potential for recall bias and widely disparate number of patients between treatment groups and follow-up times between patients severely limit this retrospective study. Nevertheless, despite these major statistical flaws, the results may provide valuable information regarding the safety of multiple modalities with PDT of photodamage in a single session.

Histologic comparison of microscopic treatment zones induced by fractional lasers and radiofrequency

INTRODUCTION

Fractional photothermolysis induces microscopic, localized thermal injury in the skin surrounded by undamaged viable tissue in order to promote wound healing.

OBJECTIVE

This study evaluated acute histologic changes following each single pass of various fractional lasers and radiofrequency (RF).

METHODS

Three male domestic swine were used. We used fractional Erbium:glass (Er:glass), Erbium:yttrium-aluminum-garnet (Er:YAG), CO2 lasers, and fractional ablative microplasma RF. We analyzed features and average values of the diameter, depth, and vertical sectional areas treated with each kind of laser and RF.

RESULTS

The microscopic treatment zone (MTZ) of fractional Er:glass resulted in separation of dermoepidermal junction with no ablative zone. Fractional Er:YAG provided the most superficial and broad MTZ with little thermal collateral damage. Fractional CO2 resulted in a narrow and deep "cone"-like MTZ. Fractional RF resulted in a superficial and broad "crater"-like MTZ.

CONCLUSIONS

This study provides the first comparison of MTZs induced by various fractional lasers and RF. These data provide basic information on proper laser and RF options. We think that these findings could be a good reference for information about fractional laser-assisted drug delivery.