A Picosecond Advances for Pigmented Lesions and Photorejuvenation Clinical Bulletin

Clinical White Paper Picosecond Advances for Pigmented Lesions and Photorejuvenation: The Uniqueness of the Four Wavelengths of PicoWay Prof. Firas Al-Niaimi, MD overall rejuvenation and for (acne) scarring applications[*]. The 532 Resiolve Fusion handpiece is a novel handpiece Background encompassing a fusion technology with a high fluence central beam surrounded by a lower fluence ring beam of Picosecond lasers (PSL) are a novel advancement in the energy. The result is a higher coverage with more dispersed laser field with the ability to create a pulse of less than one effect. nanosecond (1 ns = 1000 ps). They have been available in the dermatologic environment and approved by the The fractional technology of the PSL differs from the non- US FDA since 2012 [1]. The use of PSL beyond tattoos is ablative fractional lasers using water as a chromophore now common practice in the treatment of a wide range since the latter have a linear association between of applications, such as pigmentation (epidermal/dermal), fluence and depth; whereas the fractional PSL induces a rejuvenation and scars [2]. 3-dimensional shockwave injury with the formation of LIOBs as well as propagation of the shockwave in all directions The advent of ultrashort pulsed PSL has transformed the way and therefore the fluence is not linearly related to the depth. tattoos and benign pigmented lesions are treated in clinical A study supervised by the author (Al-Niaimi F) did show a practice [3]. Unlike long-pulsed lasers (milli to microsecond positive correlation between fluence and ultimate collagen domain) and Q-switched lasers (nano second domain), the deposition independent from the depth, highlighting the PSL deliver very short pulse durations in one trillionth of linear correlation between fluence and LIOB formation[8]. a second (range) giving a predominantly photomechanical effect, labelled as “shockwave injury“, rather than a The most recent addition to the PicoWay® system is the photothermal one (a resultant greater photoacoustic than 730 nm handpiece with the shortest pulse of 250 ps.. photothermal effects). This is relevant as the clinical effect This wavelength improves 30% melanosome/melanin will be more enhanced for small particle shattering with a absorption and 43% relative to blood (50:1 ratio) higher higher safety margin and less complications, particularly as absorption compared to 785 nm wavelength .[2,*] Normally, in higher Fitzpatrick Skin Types .[4-6] this hand-piece is preferred for several reasons: depth penetration and safer in darker skin, less risk of purpura, The fractional handpiece of the PSL (holographic beam better positioning and shorter pulse duration ( e.g., splitter in Picoway®) creates a shockwave injury in the skin compared with 694, 755 and 785 nm) at 250 ps [9]. that leads to the formation of micro bubbles that expand and collapse leading to a cascade of events involving cell- PicoWay® Resolve Fusion™ 532 nm signaling and cytokine upregulation. These vacuoles are Hand-piece termed light-induced optical breakdown (LIOB) [7]. The 532 nm Resolve Fusion™ provides an array of Candela’s PicoWay® system is a pulsed PSL system with microbeams which combine a high fluence central beam high peak power and the shortest pulse durations for with a low fluence peripheral rim allowing for greater improved therapies using photothermal and photoacoustic coverage per pass with less impact in the central beam effects [*]. The Picoway® system is a PSL with a total of six leading to less side-effects, such as petechiae especially handpieces (fractional and non-fractional) spanning across highlighted in higher skin types [6]. This fractionated beam four wavelengths (532, 730, 785 and 1064 nm). gives a distinct microscopic injury termed light-induced optical breakdown with cell-signaling for rejuvenation The Transition: from Full Beam to and a mechanical destruction of melanosomes leading Fractional Delivery Technology to enhanced clearance of diffuse pigmentation with little downtime. It is still 100 multi-spot beam delivery but, in this For full beam delivery technology (single beam), PicoWay® case, surrounded by a diffuse ring. offers the Zoom (532 and 1064 nm), 730 and 785 nm hand-pieces aiming mostly at tattoos, pigmentation and skin rejuvenation. Instead for fractional (100 multi-spot) beam delivery the system suggests Resolve (532 and 1064 nm) handpieces which are kept valid for pigmentation and

Case 1 Figure 1: After Before Case 1 is a 53-year old woman with skin type 3 and photodamage with benign lentigines and freckles on the face. The novel 730 nm handpiece was used first as a spot treatment for the individual benign lesions. The spot size of 4 mm was used with a fluence of around 1 J/cm2 adjusted down to the use of 2 mm between 2.6 and 3 J/cm2 depending on the achievement of the clinical endpoint which is light whitening of the lesions preserving the surrounding tissue. In the light-coloured lesions an additional pass was performed. Subsequently, the 532 nm Resolve Fusion handpiece was used with a fluence of 0.5 mJ in 2 passes over the entire face with erythema as a clinical endpoint. Post care moisturizer and sunblock were advised. Marked improvement in the pigmentation was noted during her second visit in 4 weeks follow-up (figure 1). Case 2 Case 3 Case 2 is 45-year old Chinese woman with skin type 4 Case 3 is a 30-year old Asian man with facial atrophic presented with discrete lentigines on the zygomatic area acne scars. He had previous treatment with microneedling of her right cheek which she was keen to get rid of. The elsewhere with limited results. He was treated with the 730 nm handpiece was used with both the 2 and 3 mm 1064 Resolve fractional handpiece over a course of six spot with fluences ranging between 1.6 to 2.6 J/cm2 until treatments starting with a fluence of 2.1 mj (maximum the desired endpoint of mild whitening was achieved. A 2.7 mj) with five to six passes on each cheek on average, potent topical corticosteroid cream was prescribed to Mild erythema was the endpoint. Aftercare was with a use twice daily for 3 days together with meticulous sun bland emollient and sun protection (figure 3). protection. Clearance of the lesions was achieved with no adverse effects (figure 2). Figure 3: Figure 2: Before After Before After

Conclusion The Picoway system is an advanced and powerful PSL with a total of six handpieces (zoom, non-fractional 532 and 1064, 730, and 785; Resolve 532, 1064, and the novel 532 Resolve Fusion). The system has the shortest pico pulse durations with the highest peak powers enabling for a true photoacoustic effect. It has high clinical efficacy and an excellent safety profile. References 6. Miyata N. (2020). Picoway clinical insights: innovative picosecond laser with 4 wavelengths. Candela 1. Forbat, E., & Al-Niaimi, F. (2016). The use of Corporate White Paper. picosecond lasers beyond tattoos. Journal of Cosmetic and Laser Therapy, 18(6), 345-347. 7. Hwang, C. Y., & Chen, C. C. (2020). Serial change in laser-induced optical breakdown by 1064 nm 2. Mehrabi, J. N., Friedman, O., Al-Niaimi, F., & Artzi, Nd: YAG picosecond laser. Photodermatology, O. (2020). Retrospective photographic review of photoimmunology & photomedicine, 36(1), 63-64. nontattoo indications treated by picosecond laser. Journal of Cosmetic Dermatology, 19(3), 612-621. 8. Kirsanova L, Araviiskaia E, Rybakova M, Sokolovsky E, Bogantenkov A, Al-Niaimi F. Histological 3. Al-Niami, F. (2021) Novel picosecond handpieces for characterization of age-related skin changes following the treatment of pigmentation. The PMFA Journal the use of picosecond laser: Low vs high energy. (Case Report), 8(3), Feb./Mar. Dermatol Ther. 2020 Jul;33(4):e13635. 4. Wu, D. C., Goldman, M. P., Wat, H., & Chan, H. H. 9. Lipp, M. B., Angra, K., & Wu, D. C. (2021). Safety (2021). A systematic review of picosecond laser in and efficacy of a novel 730 nm picosecond titanium dermatology: evidence and recommendations. Lasers sapphire laser for the treatment of benign pigmented in surgery and medicine, 53(1), 9-49. lesions. Lasers in Surgery and Medicine, 53(4), 429- 434. 5. Chan, J. C. Y., Shek, S. Y. N., Kono, T., Yeung, C. K., & Chan, H. H. L. (2016). A retrospective analysis on the management of pigmented lesions using a picosecond 755 nm alexandrite laser in Asians. Lasers in Surgery and Medicine, 48(1), 23-29. Footnote [*] PicoWay CE Mark Disclaimer: All contents of this material are for informational purposes only and provided by Candela without warranties of any kind. Healthcare professionals are solely responsible for making their own independent evaluation as to the suitability of any product for any particular purpose and in accordance with country specific regulations. The availability of products and the indications mentioned in this material is subject to the regulatory requirements and product registration status in each country. Refer to your User Manual for your country specific indications. Products and technical specifications may change without notice. Please contact Candela for more details. © 2021 Candela Corporation. This material contains registered and unregistered trademarks, tradenames, service marks and brand names of Candela Corporation and its affiliates. All other trademarks are the property of their respective owners. All rights reserved. PU01944EN Rev. A