QS Nd YAG Laser: Single Technology with Multiple Cosmetic Applications
Apratim Goel*, Vallari Gatne and Masuma Molvi
Consultant
Dermatologist, Cutis Skin Studio, Mumbai, Maharashtra, India
*Corresponding author: Apratim Goel,
Consultant Dermatologist, Cutis Skin Studio, Mumbai, Maharashtra, India, Tel: +
022-23672627/37/9833889680; Email: mdcutis@hotmail.com
Received
Date: 22 May, 2016; Accepted
Date: 25 August, 2016; Published Date: 08 September, 2016
Citation: Goel A, Gatne V, Molvi M (2016) QS Nd YAG Laser: Single Technology with Multiple Cosmetic Applications. Gavin J Dermatol Res Ther 42-45.
Introduction: Nd:YAG (neodymium-doped yttrium aluminum garnet)
laser is the most widely used pigment specific laser used in dermatology. The
effect of Q-switching allows delivery of powerful laser pulses with high peak
power within short pulse duration. Following the theory of selective
photothermolysis, melanosomes and tattoo particles are selectively targeted.
Multiple Applications: Earlier used for just tattoo removal and pigmentary
disorders, Q-switched Nd YAG laser (QSNDYL) is now becoming a popular choice
for skin rejuvenation, dermatoheliosis, vascular lesions, skin lightening, acne
and onychomycosis as well. Further, with the introduction of novel picosecond
domain pulses and QSNDYL working at wavelengths other than 1064 and 532nm, a
whole new arena of applications and possibilities have unraveled themselves.
Low fluences are regularly used for conditions like melasma, skin rejuvenation
and vascular lesions.
Conclusion: QSNDYL is a practical, ever-evolving non-ablative laser
system with a wide range of applications. Even though its spectrum of
complications, especially in skin type IV and above, cannot be overlooked,
neither can its versatility. It is a must have technology in a cosmetic setup.
1. Introduction
A non-ablative and selective photothermolysis system, quality
switched Nd:YAG laser (QSNDYL) is a cosmetic dermatologist’s very own
workhorse. Originally developed by Geusic et al. in 1964, it is commonly
used to treat a variety of pigmentary disorders and for tattoo removal. It
causes dermal, epidermal and melanocytic melanosome rupture and destruction of
dermal melanophages, thereby decreasing the pigment in the lesion [1,2].
1.1. What Is Q-Switched Nd:Yag Laser?
To explain simply, laser is a type of light that carries only a
specific wavelength, as opposed to visible light that carries a range of
wavelength. Qualities of laser light waves are that they are parallel to each
other and are in the same phase. Visible lights are not parallel and does not
move temporally in the same phase. There are many lasers in the market. Nd:Yag
laser is named after the laser medium, Neodymium:yytrium-alumunium-garnet.
It comes in 2 wavelengths, 1064 nm and 532 nm. It is a
non-ablative laser. This means that there is no break in skin tissue continuity
during the treatment. It is designed to target pigment cells penetrating 3 to 6
mm [2]. Q-switching refers to the technique of making the laser produce a high
intensity beam in very short pulses. 1064 nm, in the infrared wavelength,
targets deeper pigment while 532 nm wavelength is useful for superficial
lesions [3]. This specific wavelength are absorbed preferentially by pigments
(melanin) and the resultant heat will cause generation and propagation of waves
that cause damage to the cells containing pigment. These damaged cells will
then be cleared from the site resulting in lightening of the pigmented site.
1.2. Applications Of Qs
Nd:Yag Laser In Cosmetic Dermatology Practice
In a cosmetic practice in our part of the world (India), QS
NdYAG laser is the most talked about technology in a cosmetic technology mainly
because of the eternal demand for fairness and also because the pigmentary
disorders are in abundance. In a cosmetic practice, there is a demand for
treatments with no or minimal downtime. QS NdYAG laser is ideal for multiple
uses in cosmetic practice. Following are established uses of this laser
technology:
1.3. Tattoo
Though Q-switched ruby and Q-switched alexandrite lasers have
been earliest lasers for tattoos, Q-switched NdYAG 1064 nm, due to its longer
wavelength, higher fluence, and shorter pulse, has emerged as a better laser
for the black and dark blue/ black tattoo pigment. The textural changes,
scarring, and hypopigmentation of earlier lasers are remarkably low [4] (Figure
1). QSNDYL 1064 nm is a longer wavelength, minimally absorbed by epidermis,
hence is the safest choice with minimal adverse effects in skin type VI and
above [2].
Recently, the picosecond (ps) -domain pulses have been found to
be more effective than ns pulses for removing all tattoos. While using the
former, lower fluences are capable of delivering desired results as higher peak
powers and superior photoacoustic effect over longer pulse-durations are
attained. Furthermore, the removal of yellow ink more efficiently is an
added advantage [4].
1.4. Melasma
Melasma is an agonizing pigmentary disorder, notorious mainly
due to its tendency to recur. Topical formulations like triple therapy; Kligman
and Willis’ formula; broad-spectrum photoprotection and camouflage constitute
the first line therapy while chemical peels find their place in the second.
Even till date, Laser and light therapies represent the third line, reserved
mainly for refractory cases (Figure 2) as they pose a risk of worsening the
disease. Nevertheless, low fluence mode laser toning with QSNDYL 1064nm has
emerged as an effective option without serious side effects [5]. Longer
wavelength penetrates deeper to target the dermal melanin without affecting the
overlying epidermis and the lower fluence causes rupure of melanonsomes and
release of the fragmented melanin granules in the cytoplasm [6].
1.5. Vascular lesions
QSNDYL can be used to treat spider and thread veins, capillary
malformations, varicose veins, telangectasia and small hemangionas. Short pulse
duration, low fluence and quick repetitive bursts help in targeting superficial
dermal vessels [3]. Lately, a novel low-fluence 585 nm QSNDYL was introduced
and found efficacious in the treatment of post-acne erythema with negligible
discomfort and quantifiable improvement. The clinical study included 25
patients with post-acne erythema, who underwent 3 sessions of laser treatment
at 0.30-0.5 J/cm2 fluence and 5mm spot size at 2-weekly
intervals and at the end of 6 weeks displayed quantifiable improvement. Hence,
in this lies a new therapeutic modality for inflammatory acne and initial acne
scarring [7].
1.6. Onychomycosis
Oral antifungals have ruled the onychomycosis therapy scene for
decades. However patients are alarmed by drug interactions and systemic adverse
effects as the treatment is continued for months. Surgical treatment too results
in prolonged pain. In a study by Moon et al, 13 patients were subjected to 5
monthly sessions of long-pulsed Nd YAG laser treatment, of which all responded
with more than 50% improvement in the condition. Therefore, a latest, safe and
effective therapy has emerged to improve this ungual pathology; by eradicating
the causative fungi; as well as the aesthetic appearance of the nails [8].
1.7. Skin Rejuvenation
and Rhytides
Another popular use of QSNDYL is laser toning for skin
rejuvenation done at low fluence (less than 5j/cm2) and large spot
size (8mm) settings. Improvement of pore size, sebaceous secretion, and skin
texture and tone summarizes the rejuvenation effect (Figure 3) which is
attributed to sub-threshold thermal heating of the dermis resulting in increase
in collagen, elastin and dermal remodeling [6]. In contrast to the previous
belief, topical carbon solution application did not enhance laser efficacy in
several studies [9].
A study of human skin fibroblasts explained the pathogenesis of
use of QSNDYL in this condition. It concluded that synthesis of type I and III
procollagen, inhibition of collagen degradation by downregulation of matrix
metalloproteinases and upregulation of its tissue inhibitors is the underlying
mechanism for the effect. Further, the investigators stated QSNDYL to be more
effective for skin rejuvenation than the KTP laser [10].
1.8. Dermatoheliosis
Photodamaged skin is described by thinning of the epidermis and
dermis, coarse skin texture, rhytides, pigmentation, and telangiectasias.
1064nm QSNDYL can improve each of these components. Therefore its use in
dermatoheliosis is promising, that too in the absence of an obvious downtime
[11].
1.9. Hair reduction
The laser in talk has been effectively used for hair reduction
since many years. However, the longer-pulse (ms) has been shown to be more
effective in safely removing hair than QSNDYL [3]. Inspite the recent advances
in hair removal, fine hair still remain a therapeutic challenge for
cosmetologists to face up to. An electro-optic QSNDYL was devised for the
permanent treatment of unwanted fine hair and showed a high-patient
satisfaction rate. Further studies are needed to reinstate its efficacy
[12].
1.10. Pigmented lesions
Post-inflammatory hyperpigmentation, lentigens, freckles,
melanocytic nevi like nevus of Ota (Figure 4), nevus of Ito, Hori’s nevus etc
and Mongolian spots are few common pigmentary conditions where QSNDYL is used
even as a first line of treatment. It highly absorbs melanin at 532nm and
hence, even up to date no other laser like the Q switch ruby laser, and
alexandrite laser or light based device like the intense pulsed light (IPL)
matches its utility in these conditions [2].
1.11. Inflammatory and non-inflammatory acne
For ages, drugs in oral or topical form and chemical peels ruled
the scene when it came to treatment of acne vulgaris. Nowadays, laser and light
based devices, though less popularly, are being used for the same purpose with
impressive results. A novel technique using dual mode
(quasi-long pulse and Q-switched mode)
1064-nm NdYAG laser following topically applied carbon suspension
reckons to improve inflammatory as well as non-inflammatory acne with minimal downtime.
The laser penetrates the dermis and selectively targets sebaceous glands
causing thermal damage and acne clearance [13].
1.12. Laser facial & Skin Whitening
In India and also in most parts of Asia, skin whitening and
fairness is a huge cosmetic demand for most practitioners. Laser facial with
low fluence, large spot size 1064 nm, is ideal for immediate skin lightening as
well as hair reduction with minimum or no downtime. An immediate skin cooling
and application of a facial peel off mask gives an immediate skin brightening
and even skin tone. This procedure can be repeated once in 4-6 weeks for
maintained results.
2. Complications of QSNDYL Laser
Like any laser, use of QSNDYL too is haunted by few
complications. However, most are transient reactions and do not require
termination of treatment. These include erythema, physical urticaria, acneiform
eruption, petechiae, whitening of fine hair and rebound hyperpigmentation. On
the other hand, occurrence of mottled hypo/ hyperpigmentation, leukoderma,
severe urticaria or acneiform eruption and activation of herpes simplex
warrants modification of laser parameters and if required, even termination of
therapy. Ghost shadows and scarring are adverse effects associated with tattoo
removal at higher fluencies [14]. Recently, a chinese study interpreted the
factors inducing mottled hypopigmentation associated with QSNDYL laser toning
done for melasma and skin rejuvenation. Low fluence, large spot size, frequent
treatments i.e. weekly or fortnightly, done for longer periods of 1-2 years
were deemed to be responsible. They further opined that this hypopigmentation
doesn’t respond well to treatment and persists for many years. Hence, caution
is advised. Indication, skin type, parameters and duration of therapy should be
well considered before undertaking laser treatment [15].
3. Conclusion
The QSNDYL is one of the most resourceful and versatile lasers
in dermatology. No other laser provides such a wide spectrum of applications,
that too without much downtime. However, complications like recurrence,
post-inflammatory hyperpigmentation, mottled hypopigmentation and ghost shadows
still limit its use in various conditions. It is a therapeutic gold standard
for tattoo removal and pigmented lesions and many more of its utilities are
either being studied or yet to be discovered. Furthermore, in today’s day and
age, the proactivity about delaying the natural aging process as well
reversing, what can be reversed, of the existent damae has made QSNDYL a
cosmetologists ace tool for treatment of skin pigmentation, photoaging,
rhytides and dullness. Nonetheless, with so many effective anti-ageing
modalities already present, it definitely also finds its place as a maintenance
system. It is definitely a must for a cosmetic practice considering its
multiple applications.
Figure 1: Tattoo removal; after 3 sessions of QSNDYL.
Figure2: Melasma; after 6 sessions of QSNDYL.
Figure3: Laser toning for skin rejuvenation, tone and textural improvement; after 6 sessions of QSNDYL.
Figure4: Nevus of Ota; after 6 sessions of QSNDYL.
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- Jung JY, Hong JS, Ahn CH, Yoon JY, Kwon HH and et al., (2012) Prospective randomized controlled clinical and histopathological study of acne vulgaris treated with dual mode of quasi-long pulse and Q-switched 1064nm Nd:YAG laser assisted with a topically applied carbon suspension. J Am Acad Dermatol, 66: 626-33.
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