An Atlas of Optical Coherence Tomography (OCT): Elucidating In Vivo Differences of Scar Types Using OCT in Order to Guide Laser Treatment Parameters.

Objective: When using laser therapy to effectively treat scars, the choice of treatment parameters depends on the knowledge accuracy of the underlying scar pathology, which is often difficult to judge by gross physical exam. As such, more quantitative measures are needed. In recent years, optical coherencetomography (OCT) has shown promise as a real-time imaging technolgoy of skin microstructure. A key step in developing a methodology for utilizing OCT to develop a comprehensive 'atlas' of OCT characteristics of a wide variety of scar types. This atlas may then be used as a tool for selecting the optimal treatment modality and parameters for each scar type. Methods: One hundred and fifty scars of a wide range of anatomical locations were imaged using OCT, capturing both vascular and structural data. A variety of scar etiologies (e.g. burn, surgical, traumatic) and types (e.g. hypertrophic, keloidal, atrophic) were included. Comparator scans were also taken from normal, unscarred skin. Results: OCT revealed morphological differences in the epidermis and dermis between scars and normal tissue, and between scar subtypes. Features affected by scar pathology included epidermal thickness, skin surface texture, dermal epidermal junction rugosity, blood vessel density, vessel shape and diameter, vessel direction and vascular network, dermis scattering intensity and non-uniformity. Each scar subtype showed consistent characteristics distinct from other scar subtypes. Limitations: This was a single-site study of a patient population in South Florida. Conclusion: OCT is a powerful new objective tool for the clinician to utilize in the pursuit of effective laser treatment parameters by enabling personalized treatment based on individual scar characteristics in order to maximize treatment capabilities.

Prospective study of intense pulsed light versus pulsed dye laser with or without blue light in the activation of PDT for the treatment of actinic keratosis and photodamage.

BACKGROUND: Exposure to ultraviolet (UV) light from the sun is known to have a deleterious effect on the skin. Repeated insults to the dermal matrix from UV radiation result in the clinical signs of photodamage, including changes in skin elasticity, color, and texture. UV radiation also leads to the accumulation of DNA mutations and promotes tumor development, resulting in the formation of cutaneous precancerous and cancerous lesions. Continuous-wave incoherent blue light, intense pulsed light (IPL), and pulsed dye laser (PDL) are safe and efficacious light sources commonly used for aminolevulinic acid photodynamic therapy (PDT). The aim of this study was to prospectively evaluate the efficacy of PDT for the treatment of photodamage and actinic keratoses using four different combinations of light sources: PDL, PDL + blue light, IPL, and IPL + blue light. STUDY: A total of 220 patients with either photodamage or actinic keratosis (AK) were recruited from the Miami Dermatology Laser Institute (Miami, FL) and were assigned prospectively to undergo one PDT treatment with one of the four light options: PDL, PDL + blue light, IPL or IPL + blue light. Of the 220 patients enrolled in treatment groups, 214 patients completed the study. Of the 214 patients, 88 received treatment for AK, and 126 received treatment for photodamage. All patients gave their consent to participate in the study and to allow their photographs to be utilized for the purpose of scientific presentations. RESULTS: Treatment with IPL resulted in a 70.8% reduction of actinic keratoses at a 1-month follow-up. Treatment with IPL and blue light 84.4% reduction of actinic keratoses at 1 month follow up. Treatment with PDL 70.5% reduction of actinic keratoses at 1 month follow up. Treatment with PDL and blue light 69.3% reduction of actinic keratoses at 1 month follow up. Treatment with IPL resulted in an improvement score of 2.9. Treatment with IPL and blue light resulted in an improvement score of 3.0. Treatment PDL resulted in an improvement score of 1.5. Treatment with PDL and blue light resulted in an improvement score of 1.8. CONCLUSION: Although all four treatment groups led to some improvement in signs of photoaging, IPL + blue light again demonstrated increased efficacy when compared to IPL, PDL, and PDL + blue light treatment groups. Results from our study were limited by an unequal distribution between treatment groups and a lack of follow-up beyond a 1-month period and warrant further research.

Randomized, Controlled Early Intervention of Dynamic Mode Fractional Ablative CO2 Laser on Acute Burn Injuries for Prevention of Pathological Scarring.

BACKGROUND AND OBJECTIVES: This study challenges the currently accepted treatment parameters of waiting 1 year following burn injury to treat the resultant scarring. It assesses the impact of treating burn and trauma wounds at less than 3 months of injury on scar formation, providing a new temporal paradigm to patients in the prevention and minimization of scar formation. STUDY DESIGN/MATERIALS AND METHODS: This randomized clinical trial included 19 patients with moderate-to-severe acute burn injuries less than 3 months from injury. The treatment areas underwent three fractional ablative CO2 laser treatments at 8-week intervals. The primary outcomes were improvement in the Manchester Scar Scale (MSS) and photography. Secondary outcomes were optical coherence tomography (OCT), treatment time, immediate post-treatment response, and histology. RESULTS: Upon blinded evaluation, 100% of treatment areas were correctly identified when compared with control. MSS scores before and after treatment were totaled with an averaged sum of 13.33 per scar at baseline to 8.39 after treatment, a 63% average improvement versus control (P < 0.001). Histology and OCT demonstrated a re-organization of the underlying skin structure. The average treatment time was 18 minutes. Immediate post-treatment responses were limited to mild-to-moderate erythema. CONCLUSIONS: Early intervention with ablative fractional laser on acute traumatic wounds resulted in significant decrease of scar formation compared with untreated areas on the same wounds, providing an impactful new time course to treat severe burn and trauma injuries. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Re-pigmentation of Hypopigmentation: Fractional Lasers vs Laser-Assisted Delivery of Bimatoprost vs Epidermal Melanocyte Harvesting System

Background: Hypopigmentation is a common cutaneous manifestation that frequently poses a therapeutic challenge for dermatologists. Current treatments have varying efficacies and rarely provide patients with long-term results. However, new treatments are emerging, and head-to-head studies comparing these treatments are warranted. Methods & Materials: In this prospective, Institutional Review Board (IRB)-approved, double-blinded study, 40 subjects with moderate to severe hypopigmentation were randomized into 1 of 4 treatment arms; non-ablative fractional laser, ablative fractional laser, ablative fractional laser with laser-assisted delivered bimatoprost, and an epidermal harvesting system. Results: All patients in this study showed improvement regardless of the treatment modality. The average improvement score was calculated on a 0 to 4 scale, and Group 3 (fractional ablative laser and bimatoprost) was found to have a significantly higher average improvement than all other treatments, with 76% of the patients exhibiting at least a grade 3 (over 50%) improvement over the treatment course. Group 1 (non-ablative fractional) also had a significantly higher average score compared with group 2 (fractional ablative laser). Conclusion: New and emerging therapies have shown promise in helping re-pigmentation of cutaneous hypopigmentation. In this head-to-head trial, it was shown that laser-assisted delivery of bimatoprost had a greater statistically significant improvement compared with 3 possible treatment modalities for stimulation of pigment in medical and cosmetic hypopigmentation. J Drugs Dermatol. 2019;18(11):1090-1096.

Efficacy of Combined Intense Pulsed Light (IPL) With Fractional CO2 -Laser Ablation in the Treatment of Large Hypertrophic Scars: A Prospective, Randomized Control Trial.

BACKGROUND AND OBJECTIVES: Scar rehabilitation is a complex process that incorporates medical, surgical, and physical therapeutic measures to best restore function and visual normalcy. Lasers have emerged as essential tools in the management of scars, with devices available to address scar size, dyschromia, and contour irregularities. As different lasers treat these different features, multi-laser, same session therapeutic approaches may offer a more comprehensive approach to scar revision. In this study, we aim to demonstrate the effect of a combinatorial, same session treatment with intense pulsed light (IPL) and fractional ablative CO2 as compared to single laser treatment with fractional ablative CO2 laser alone or control in the treatment of mature hypertrophic scars. MATERIALS AND METHODS: This institutional review board-approved, randomized controlled trial, enrolled 23 healthy adults with large (>100 cm2 ) hypertrophic scars who were randomized to one of three treatment arms: (i) IPL and CO2 ablative fractional laser (AFL), (ii) CO2 AFL alone, and (iii) control (no laser treatment). Subjects underwent a total of four treatment sessions at 6-8-week intervals with follow-up visits at 1, 3, and 6 months following the last treatment session. Primary endpoints included blinded scoring of before and after photographs via the Manchester Scar Scale (MSS). Secondary endpoints included the Patient-Observer Scar Assessment Scale (POSAS). RESULTS: As compared to control and CO2 AFL laser alone, the combination of CO2 AFL and IPL demonstrated statistically significant improvement across a greater number of scar domains, as assessed by the MSS. 100% of subjects in both treatment groups showed a statistically significant decrease in the POSAS scale after the series of four treatment sessions. No adverse events were reported. CONCLUSION: Treatment with combined IPL and CO2 AFL demonstrated higher average improvements across the majority of assessed scar domains, as compared to both control and CO2 laser alone. The difference was not statistically significant in overall MSS score as expected due to the role of CO2 as the main source of improvement. However, only the combination group had statistically significant improvement in both color and texture. These findings support the assertion that a multi-photo-thermolytic approach with combined IPL and CO2 AFL can have a positive impact on the treatment of hypertrophic scars by using multiple wavelengths to maximize laser-skin interactions in targeting the different chromophores expressed in scar tissue. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Anesthesia and increased hypercarbic drive impair the coordination between breathing and swallowing.

BACKGROUND: Coordination between breathing and swallowing helps prevent aspiration of foreign material into the respiratory tract. The authors examined the effects of anesthesia and hypercapnia on swallowing-breathing coordination. METHODS: In a randomized controlled crossover study, general anesthesia with propofol or sevoflurane was titrated using an up-down method to identify the threshold for suppression of the motor response to electrical stimulation of the forearm. Additional measurements included bispectral index, genioglossus electromyogram, ventilation (pneumotachometer), and hypopharyngeal pressure. During wakefulness and at each level of anesthesia, carbon dioxide was added to increase the end-tidal pressure by 4 and 8 mmHg. A swallow was defined as increased genioglossus activity with deglutition apnea and an increase in hypopharyngeal pressure. Spontaneous swallows were categorized as physiological (during expiration or followed by expiration) or pathological (during inspiration or followed by an inspiration). RESULTS: A total of 224 swallows were analyzed. Anesthesia increased the proportion of pathological swallows (25.9% vs. 4.9%) and decreased the number of swallows per hour (1.7±3.3 vs. 28.0±22.3) compared to wakefulness. During anesthesia, hypercapnia decreased hypopharyngeal pressure during inspiration (-14.1±3.7 vs. -8.7±2 mmHg) and increased minute ventilation, the proportion of pathological swallows (19.1% vs. 12.3%), and the number of swallows per hour (5.5±17.0. vs. 1.3±5.5). CONCLUSIONS: Anesthesia impaired the coordination between swallowing and respiration. Mild hypercapnia increased the frequency of swallowing during anesthesia and the likelihood of pathological swallowing. During anesthesia, the risk for aspiration may be further increased when ventilatory drive is stimulated.