The latest advancements in lasers

By Dr Elizabeth Raymond Brown / 01 Apr 2015

Laser specialist Dr Elizabeth Raymond Brown gives an overview of the latest technological advancements in the field of aesthetic lasers

Introduction

The concept of the laser traces back to the theory of stimulated emission proposed by Albert Einstein in 1917.1 The first experimental laser, using a synthetic ruby crystal, was demonstrated in 1960 by Theodore Maiman.1 According to Hecht,2 the development of the laser was ‘neither simple nor easy’, but in the intervening 55 years, lasers impacted every aspect of life, including surgical and non-surgical cosmetic interventions. The UK market for cosmetic interventions (consumer value) was worth £2.3bn in 2013, and it is estimated to rise to £3.6bn by 2015. 

Figure 1: Cutera Xeo treatment hand-pieces
Figure 2: Lumines ResurFX

 Non-surgical procedures (injectables, laser/light therapies) are estimated to account for 90% of procedures and 75% of the market value.3 Rarely can medical aesthetic clinics afford to invest in laser technology unless it offers a wide range of treatment modalities or unique features, with superior performance and benefits over other modalities and devices. What could be considered good examples of customisable laser and intense light devices for multi-applications include: the Alma Harmony XL, the Lumenis M22, Lynton Lumina and the Cutera Xeo (Figure 1). These systems offer versatile and expandable ‘platforms’ with

as many as 24 different treatment modalities from a single platform, helping to grow practice treatments and revenue. Devices offering fewer, but more specific applications, such as body contouring or treatment of hyperhidrosis include; the 10600 nm output of the Syneron-Candela CO2RE for ablative rejuvenation or the 1565 nm fibre laser of the Lumenis ResurFX (Figure 2), offering fractional non- ablative skin rejuvenation. 

An established marketplace

The economic downturn and subtle changes in customer demands resulted in some key mergers and acquisitions, which has brought benefits to companies, investors and consumers alike. With companies extending their product portfolios, research and development (R&D) bases, and customer support services, practitioners expect suppliers to offer reliable, high performance devices, limited or zero consumable costs, on-going clinical education and ‘on-call’ service support. Lasers are designated as ‘Medical Devices’, and thus must be CE marked and comply with applicable European Medical Device Directives (within the EU).4 Unlike the United States, the UK is not required to register laser products, but it is a legal requirement to meet the ‘Essential Safety Requirements’ of the applicable European Directives, ie. BS EN 60601-2- 22:2013.5 Laser products are classified according to the accessible laser emission, and if this exceeds limits defined in BS EN 60825-1,6 the product must be accurately labelled and must incorporate engineering features such as key switches and interlocks. Manufacturers must also provide adequate instructions for safe and appropriate use. Laser eye protection has to be CE marked and comply with BS EN 207:2009,7 the ‘European Directive on Personal Protective Equipment’. As a certified laser protection advisor (LPA), I would strongly advise those purchasing equipment directly from non-European websites, or pre-used devices to seek independent advice on product safety compliance, output calibration and suitability of treatment protocols and protective eyewear.

Extending treatment opportunities

All aesthetic laser and light-based therapies exploit the concept of selective absorption of incident radiation by a given chromophore or target, as described by the theory of Selective Photothermolysis.8 To achieve an efficacious and safe clinical outcome, specific device variables must be selected and controlled according to the presenting condition to be treated and patient factors such as skin type, hair colour etc.
These variables include:
Wavelength (nm / ?m) – determining absorption by a given chromophore, and depth of penetration into tissues.
Pulse duration (ms / ?s / ns / ps) – determining rate of heating of target tissues and thus interaction mechanism, eg. photochemical, photothermal, photomechanical.
Energy, power, fluence (J, W, J cm-2 according to output) determining amount of energy/power delivered to the tissues. 
Treatment area (mm, cm-2) – affecting depth of penetration into tissues, thermal diffusion of heat and treatment time. 

It is the subtle but significant refinement of these variables that offer further opportunities to improve clinical efficacy, reduce treatment times and enhance patient comfort. For example, the introduction of ‘fractional’ technology – delivering energy in micro- spots rather than over a full beam area – had a significant impact on extending both ablative and non-ablative treatments.9 Other innovative advances are outlined below:

Wavelengths – adding more and ‘mixing’ them up

A number of devices offer multiple wavelengths and interesting ways of delivering them: 

  • Independtent wavelength delivery – eg. Syneron-Candela GentleMax Pro, offers an Alexandrite (755 nm) and an Nd:YAG (1064 nm) output for hair reduction, allowing treatment of all skin types and pigmented and vascular lesions
  • Sequential wavelength delivery – eg. Cynosure Cynergy Multiplex technology emits a pulsed dye (585 nm) beam milliseconds before the Nd:YAG (1064 nm) output for increased absorption by methemoglobin and enhanced treatment of vascular lesions 
  • Simultaneous wavelength delivery – eg. The Quanta System Duetto MT laser (Figure 3), distributed by Lynton Lasers, can emit Alexandrite (755 nm) and Nd:YAG (1064 nm) wavelengths in a single emission in varying proportions. Mixing the efficacy of the Alexandrite with the safety of the Nd:YAG offers treatment for challenging conditions such as reducing fine hair in darker skin types. 

Rarely can medical aesthetic clinics afford to invest in laser technology unless it offers a wide range of treatment modalities 

Pulse durations – ever shorter

Some of the most recent product advances have come from the ability to produce reliable and repeatable ultra-short picosecond (ps, 10-12 s) pulses of energy, previously the reserve of the research laboratories. Picosecond pulses induce photodisruption – a physical effect associated with optical breakdown that results in plasma formation and shock wave generation.10 Photodisruption is a well-known tool of minimally invasive surgery such as posterior capsulotomy and laser- induced lithotripsy of urinary calculi.
The nanosecond pulses (ns, 10-9 s) of Q-switched lasers are successfully used for tattoo removal and treatment of pigmented lesions. However, picosecond pulses can produce incredibly high peak powers from lower pulse energies – still causing optical breakdown but with less disruptive effects to surrounding tissue.10 Devices exploiting this technology include:  

  • Cynosure PicoSure, dual wavelength (755 nm / 532 nm) laser: Cynosure has exploited the laser-induced optical breakdown in tissues via their FOCUS lens array to include treatment of acne scars and wrinkles. Brauer et al11 have shown new collagen and elastin production, similar to fractional ablative lasers, but without the side effects and downtime.
  • Syneron-Candela PicoWay (Figure 4), dual wavelength (1064 nm / 532 nm) laser: claimed to remove multi-coloured tattoos, recalcitrant tattoos and pigmented lesions.
  • Cutera enlighten: This is a dual wavelength (1064 nm / 532 nm) laser offering both nanosecond and picosecond pulse durations (fixed), in one device, which with their variable spot sizes claimed to offer removal of both epidermal and dermal pigmented lesions.

To achieve an efficacious and safe clinical outcome, specific device variables must be selected and controlled according to the presenting condition to be treated and patient factors such as skin type, hair colour etc.
Figure 3: Quanta Duetto MT Laser
Figure 4: Syneron - Candela PicoWay

Treatment areas – bigger, faster, cooler

Patients not only expect great results, but also want fast and comfortable treatments, especially with hair reduction. Increasing treated area, scanned beams and comfort cooling are the industry’s response to these demands. For example:

  • Soprano from Alma Lasers (Figure 5) is well known for its SHR hair removal (high repetition of short pulses to achieve high average power) and their in-motion treatment technique. Extending this technology further is the Soprano Ice diode laser, with large spot size and ICE contact cooling designed to enhance patient comfort.
  • A new device, recently available in the UK via Aster International Ltd, is the German Medical Engineering Linscan 808 diode laser (Figure 6). A novel method of linear scanning across a treatment area of 50 x 15 mm offers high efficacy and reduced treatment times. Combined with contact cooling, Motion Control Technology (MCT) and menu driven pre-sets, this compact laser offers all the important features for safe treatment delivery. Interestingly it also offers treatment settings for Onychomycosis, as a less painful alternative to the Nd:YAG 1064 nm wavelength.
  • Building on the well established Lightsheer technology for hair reduction is the Lightsheer INFINITY, from Lumenis, offering diode wavelengths of 805 nm and 1060 nm, with a unique active pain reduction mechanism using vacuum assisted (HIT) technology and the ChillTip handpiece for effective epidermal protection. The INFINITY is a good example of the enhanced features that manufacturers need to include for both patient and practitioner with an advanced graphical interface, intuitive pre-sets and treatment defaults, benefiting the users and reducing the likelihood of inappropriate treatment settings. 
Figure 5: Alma Lasers Soprano
Figure 6: CME Linscan 808 Diode laser

 Going the extra mile – customer support

Aside from the technological advances and refinements, it is notable that manufacturers now strive to enhance the customer experience of buying and using a laser. It is no longer acceptable to take delivery with a half day training session and being left to ‘get on with it’. With such a range of devices available from an increasing number of suppliers, it can be hard to differentiate between them, and the decision on system purchase often comes down to the rapport developed with an individual sales person. Whilst perhaps understandable, this can be risky and it is wiser to focus on company pedigree, product portfolio and customer support. Reputable and trust-worthy companies offer information on compliance with safety and licensing requirements, advice on premises and room layouts, dedicated clinical trainers, workshops and educational events, webinars and learning resources, ‘user’ groups, training and business development support and rapid response to equipment service or break-down. Companies can also support their customers with contacts for finance companies, laser protection advisers (LPA) and expert medical practitioners (EMP). 



Conclusion

From the first medical treatment of a retinal tumour with a ruby laser in 1961,12 to the surgical and non-surgical interventions available today, lasers have proven themselves as precision tools for an incredibly extensive range of treatments. Pushing the boundaries with mid and far infrared wavelengths, beam delivery methods, faster treatments over bigger areas and enhanced comfort, will continue to raise expectations of both patients and users. A word of caution however, advancing the technology without advancing practitioner education is dangerous. Just because a laser can remove our wrinkles, reduce our hair growth and banish our brown spots, it should not mean that the technology becomes so readily accessible that anyone can perform such treatments. In my opinion, this is where manufacturers and distributors have a wider role to play than just selling the latest technology. But thanks to significant R&D and investment, it is now possible to deliver medical grade treatments from the most reliable, efficient and technically-advanced devices than ever before. 

References

  1. Hecht, J. (1992) The Laser Guidebook. 2nd edn. USA: McGraw-Hill
  2. Hecht, J. Beam: The Race to Make the Laser, (USA: Oxford University Press, 2005)
  3. Department of Health (2013) Review of the Regulation of Cosmetic Interventions – Final Report (UK:Department of Health, 2013) Available at: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/192028/Review_of_the_Regulation_of_Cosmetic_Interventions.pdf [Accessed 17 March 2015]
  4. British Standards Institute. European Medical Device Directives (UK: British Standards Institute, 2015) Available at: http://medicaldevices.bsigroup.com/en-GB/ourservices/european-mdd [Accessed 17 March 2015] 
  5. British Standard Institute. BS EN 60601-2-22:2013: Medical electrical equipment: Particular requirements for basic safety and essential performance of surgical, cosmetic, therapeutic and diagnostic laser equipment (UK: British Standards Institute, 2013)
  6. British Standards Institute. BS EN60825-1:2014: Safety of laser products - Part 1: Equipment classification & requirements (UK: British Standards Institute, 2014)
  7. British Standards Institute. BS EN 207:2009: Personal eye-protection equipment. Filters and eye- protectors against laser radiation (laser eye-protectors) (UK: British Standards Institute)
  8. Anderson R, Parish J. (1983) ‘Selective photothermolysis: Precise Microsurgery by Selective Absorption of Pulsed Radiation’. Science 220 (1983). p 524-527.
  9. Gold, M.H Ed. (2010) ‘Update on Fractional Laser Technology’ J Clin Aesth Dermatol, 3(1): pp.42-50 
  10. Niemz,M.H.Laser-TissueInteractions:FundamentalsandApplications.(BerlinHeidelberg: Springer-Verlag, 1996).
  11. Brauer, J, Kazlouskaya, V, Alabdulrazzaq, H, Bae, Y, Bernstein, L, Anolik, R, Heller, P, and Geronemus, R. ‘Use of a picosecond pulse duration laser with specialized optic for treatment of facial acne scarring’, JAMA Dermatology, 151(3) (2015) p 278-284
  12. Institute of Medicine (US) Committee on Technological Innovation in Medicine; Rosenberg N, Gelijns AC, Dawkins H, editors. Sources of Medical Technology: Universities and Industry. Washington (DC): National Academies Press (US); 1995. PART II, Medical Device Innovation. 3, pp 7. 

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