Ebook Lasers in dermatological practice Part 1

LASERS

in Dermatological Practice



LASERS

in Dermatological Practice
Editors

Kabir Sardana MD DNB MNAMS
Professor
Department of Dermatology and STD
Maulana Azad Medical College
New Delhi, India

Vijay K Garg MD MNAMS
Director–Professor and Head
Department of Dermatology and STD
Maulana Azad Medical College
New Delhi, India

Forewords

Ganesh S Pai
B Krishna Rau

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Lasers in Dermatological Practice
First Edition: 2014
ISBN 978-93-5152-300-0
Printed at


Dedicated to
My colleagues, friends and foes, the last of which goad us to better ourselves
constantly……
My wife Dr Supriya, who helps me to keep the balance between family and
academics
My daughter Zoya, who is the ‘zing’ in my life
My parents, Mrs Amba Sardana and Major General Sardana who have
instilled discipline in my life
and
Lastly, the Department where over the years we have honed the skills in laser
intervention
—Kabir Sardana

My family and friends
My wife Mrs Manju Garg, who has stood by me through times of strife
My son Devansh, who is pursuing his MBBS
and

My daughter Dr Ekta, who is a dentist
—Vijay K Garg



Contributors
Anil Aggrawal MD Forensic Medicine (AIIMS)
Director-Professor
Forensic Medicine
Maulana Azad Medical College
New Delhi, India
Anil Ganjoo MBBS MD
Senior Consultant Dermatologist and
Head of Dermatology
Sunderlal Jain Hospital
Saroj Hospital and INMAS
New Delhi, India
Anjali Madan MD
Senior Resident
Department of Dermatology
Maulana Azad Medical College
and Lok Nayak Hospital
New Delhi, India
Anuj Tenani MBBS PGY-II
Department of Dermatology
Maulana Azad Medical College
and Lok Nayak Hospital
New Delhi, India
Anusha H Pai MD
Consultant Dermatologist

Derma-Care Skin and
Cosmetology Center
Mangalore, Karnataka, India
Atul M Kochhar MD DNB MNAMS FAAD
Senior Specialist–Grade I
Department of Dermatology and STD
Maulana Azad Medical College
and Lok Nayak Hospital
New Delhi, India
Banwari Jangid MD
Department of Dermatology and
Venereology
All India Institute of Medical Sciences
New Delhi, India

Dharmendra Karn MD
Dermatologist
Dhulikhel Hospital
Kathmandu University
Teaching Hospital
Kavre, Nepal
Ganesh S Pai MD DVD
Senior Consultant Dermatologist
Derma-Care Skin and
Cosmetology Center
Mangalore, Karnataka, India
Inder Raj S Makin
MBBS (India) Dipl-Ing (Germany) RDMS PhD (USA)

Associate Professor

AT Still University
School of Osteopathic Medicine in
Arizona (SOMA)
Arizona School of Dentistry and
Oral Health (ASDOH)
Mesa, USA
Jaspriya Sandhu MBBS PGY-I
Department of Dermatology
Maulana Azad Medical College
and Lok Nayak Hospital
New Delhi, India
Kabir Sardana MD DNB MNAMS
Professor
Department of Dermatology
Maulana Azad Medical College
and Lok Nayak Hospital
New Delhi, India
Khushbu Goel MD
Pool Officer
Department of Dermatology
Maulana Azad Medical College
and Lok Nayak Hospital
New Delhi, India


viii  Lasers in Dermatological Practice
Narendra Kamath MD DVD
Consultant Dermatologist
Cutis Skin Care Center
Mangalore, Karnataka, India

Pavithra S Bhat MD
Kovai Medical Center and Hospital
Coimbatore, Tamil Nadu, India
Payal Chakravarty MD
Senior Resident
Department of Dermatology
Maulana Azad Medical College
and Lok Nayak Hospital
New Delhi, India
Rashmi Ranjan MD
Senior Resident
Department of Dermatology
Maulana Azad Medical College
and Lok Nayak Hospital
New Delhi, India
Rashmi Sarkar MD MNAMS
Professor
Department of Dermatology
Maulana Azad Medical College and
LN Hospital
New Delhi, India
Chief Founder and Honorary Secretary
Pigmentary Disorders Society
New Delhi, India
Shahin S Nooreyezdan
MBBS MS MCh (Plastic Surgery)
PGIMER Chandigarh

Senior Consultant
Department of Plastic, Cosmetic and

Reconstructive Surgery
Indraprastha Apollo Hospitals
New Delhi, India
Shikha Bansal MD DNB MNAMS
Specialist
Department of Dermatology
Safdarjung Hospital
New Delhi, India
Shivani Bansal MD
Senior Resident
Department of Dermatology
Maulana Azad Medical College
and Lok Nayak Hospital
New Delhi, India

Simal Soin
PG Dermatology (St Johns Institute of
Dermatology) London
MPhil Cambridge University UK

Medical Director and
Chief Cosmetic Dermatologist
Three Graces
New Delhi, India
Soni Nanda MD (Dermatology)
Shine and Smile Skin Clinic
Max Super Specialty Hospital
New Delhi, India
Sujay Khandpur MD DNB MNAMS
Professor

Department of Dermatology and
Venereology
All India Institute of Medical Sciences
New Delhi, India
Twinkle Daulaguphu MBBS PGY-I
Department of Dermatology
Maulana Azad Medical College
and Lok Nayak Hospital
New Delhi, India
Vanya Narayan MBBS PGY-III
Department of Dermatology
Maulana Azad Medical College
and Lok Nayak Hospital
New Delhi, India
Vijay K Garg MD MNAMS
Director-Professor and Head
Department of Dermatology
Maulana Azad Medical College
and Lok Nayak Hospital
New Delhi, India
Vivek Nair MBBS MD
Consultant Dermatologist
Dr Nair’s Skin Clinic (Palam Vihar)
Clinic Dermatech (Vasant Vihar
and Gurgaon)
Metro Hospital (Palam Vihar)
New Delhi, India


Foreword

Lasers have moved from the fringe of dermatology to a more
centrist path over the past decade. Fifteen years ago, when
lasers trickled into our country, they were considered to
be exotic and perhaps accessible to a select few. Cosmetic
dermatology and lasers have grown by leaps and bounds and
that necessitates that they are absorbed in the mainstream.
With close to half of the dermatologists now owning or having access to
lasers, it is important that our younger generation of dermatologists have
access to good practical textbooks as well as high quality equipment. This
book, Lasers in Dermatological Practice is best suited to educate our specialty
about the perils and pitfalls of using lasers.
Indian skin is unique since it comes commonly in 3 types—IV, V, VI.
Parameters will therefore vary depending on the skin types, a dilemma that
western books do not address. Postinflammatory hyperpigmentation will
vary in each skin type and even show variation among patients in a single skin
type. Such unpredictability and perplexing results are a cause of anxiety in a
cosmetologist at an inflexion point in his career. A comforting thought is that
our patients, except for a miniscule minority, are forgiving and compliant.
Most cases of tissue damage by laser will heal over time, nature coming to
our rescue. Our patience and reassurance will comfort patients in the interim
period.
In clinical dermatology, we have a chance to assess, judge and treat
patients. If there is an error of management, we can apply a midcourse
correction and modify therapy. Unfortunately, this is not true of lasers. A
mistake made, a poor assessment, using more or less power than required
can lead to laser burns and scarring. If it is on the face, as it is most of the
time, the consequences are not difficult to portend. Since there is no second
chance to repair damage, it is important to understand the basics of lasers
and the specifics of equipment much like reading a car manual before driving
your new car. This book does both and will hopefully lead to confident

cosmetologists and happy patients.
Ganesh S Pai MD DVD FAAD
Medical Director
Derma-Care Skin and Cosmetology Center, The Trade Center
Director-Professor, Department of Dermatology
KS Hegde Medical College, Deralakatte
Mangalore, Karnataka, India



Foreword
I thank the authors for giving me the opportunity to write the
Foreword to this excellent book, Lasers in Dermatological
Practice. The editors along with the co-authors have put
down their vast experience in the use of laser in various
dermatological conditions. It is a book of international
standards and, in particular, reference to the application
of lasers in brown and dark skin patients. Basics of laser in relation to skin
lesions are well-written.
The use of the different lasers in different dermatological lesions and the
step-by-step approach to each and every lesion is superb. The practical tips
to avoid wrong outcome is well-documented. The use of non-laser energy
sources in dermatological practice is very illuminating. The references at the
end of each chapter are apt and to the point.
The chapter on medicolegal aspects is pertinent and informative. On the
whole, it is the end result of the vast experience over the years that the editors
have acquired to write this book. I am confident that this book will find a
place in all dermatologists library.

B Krishna Rau

MS FRCS (Eng and Edin) FRCS (Thailand) (Hon) FIAMS FACG FICS FIGSC

Professor-Emeritus, Dr MGR Medical University
Honorary Fellow, American Surgical Association
President, World Federation of Society for Laser and Surgery Medicine
Chennai, Tamil Nadu, India



Preface
The genesis of this book arose from the common mechanistic approach where
we learn which buttons to push, in courses provided by the more reputable
device manufacturers just after a laser is purchased. This approach is foolish
beyond words, and can harm patients, and worse create medicolegal hazards.
There are some excellent books that we have referred to but most of them
deal with technologies that are nice to hear but too expensive to use in India.
Our book was initially planned as a companion to the hands on workshop
where the nitty gritty was left out while the topic in focus was discussed. Thus
the first edition was done with the help of Sun Pharmaceuticals. This edition
is the combined effort of Abbot and the vision of Shri Jitendar P Vij, who
convinced us to make it an elaborate yet compact book.
The book answers the three basic questions, what to do, why to do it and
how to do it? But our basic target is the dermatologists who need a step-bystep approach to the technology commonly used and not the laser that a
speaker in most conferences uses, which as a thumb rule is expensive, the
reason why the company sponsors the talk in the first place! Though the FDA
gives clearance of a device for a particular labeled indication, this cannot be
taken as any assurance that it will work safely and effectively enough to satisfy
the patients. Tragically, it may not be an understatement that a majority of
lasers bought in this country are not US FDA approved in the first place!
The book will also look at some questions that we rarely ask. What is the

histological depth of fractional lasers? Which type of atrophic scar actually
responds? Is Fr CO2 superior to Er:Glass? And many others.
As the field of cosmetic intervention usually encompasses indications
where novel non-laser technologies are used, we have covered radio­
frequency, focused USG, plasma resurfacing and LED.
The book is planned in such a way where the commonly performed
procedures are discussed which gradually move on the advanced techniques.
Practical aspects like medicolegal hazards and pearls are discussed in
the latter half of the book. Some very useful information is provided in the
appendices.
Our contributors are largely those who are experts in their field of interest.
Our own work spanning over 8 years, with almost 5,000 procedures helped us
to bridge the gap between theory and practice.
But this is not a “Cook Book” and only a guide on the best approach is
provided. Individual laser parameters can vary, thus there is no substitute
for hands-on training, which cannot be obtained in this book or sitting in a
lecture hall more so when there are hundreds sitting in it!
Hope you like the effort. More will follow soon…
Kabir Sardana
Vijay K Garg



Acknowledgments
We would like to thank our faculty residents and students of the department
some who have left to join other institutions, for their role in establishing and
developing the Laser Clinic at Maulana Azad Medical College (MAMC), New
Delhi, India.
Special thanks to Dr Vijay K Garg, Director-Professor and Head,
Department of Dermatology and STD, MAMC, who through his administra­

tive acumen, managed to get the lasers. He has given me great support and
has served as a mentor throughout my professional career. His guidance and
encouragement over the years have influenced my efforts.
A special thanks to the team at M/s Jaypee Brothers Medical Publishers
(P) Ltd, New Delhi, India, especially Shri Jitendar P Vij (Group Chairman)
and Mr Ankit Vij (Managing Director), for latching on to the project, Mr PN
Venkatraman (Vice President-International), Mr Shashikumar Sambhoo, for
handling the publicity and sales and Mr Tarun Duneja (Director-Publishing),
Mr Subrata Adhikary (Commissioning Editor), Mr Lalit kumar (DTP Operator)
for helping with the deadlines.
A big thanks to our contributors, some of whom who have worked on their
chapter on a one month deadline! Each of them is an expert in their field.
Dr Simal Soin, Dr Shahin Nooreyezdan, Dr Inder Raj S Makin and Dr
Vivek Nair have worked on such a deadline. Dr Inder Raj S Makin has also
been kind enough to review two chapters for us and his comments have been
an asset to the chapters.
Dr Khandpur and Dr Anil Agarwal have also contributed after taking out
time from their busy schedule. Dr Atul M Kochhar who is also the Purchase
Officer at our Hospital has given nuances of buying lasers.
A big thanks to Dr Antje Katzer (Ascepelion), for letting us use the images
of the company’s devices.
And lastly, our tributes to the countless patients who have taught us
dermatology and helped us to learn and relearn lasers!


xvi  Lasers in Dermatological Practice

Real knowledge is to know the extent of one’s ignorance
—Confucius

Never sacrifice your dignity to make money, but charge what you are
worth
—Christopher B Zachary


Contents
Section 1: Conventional Laser Interventions




















1. Basics of Laser-Tissue Interactions
2. Ablative Lasers
 Overview 25

 Ablative Laser Treatment of Common Conditions 52
 Step by Step Approach 86
 Atlas 93
3. Pigmented Lesions and Tattoos
 Overview 101
 Lasers For Tattoo Removal 115
 Laser Treatment of Common Pigmented Conditions 131
 Step by Step Approach 160
 Atlas 163
4. Fractional Photothermolysis
 Overview 172
 Laser Treatment of Common Conditions 204
 Step by Step Approach 229
 Atlas 233
5. Vascular Lasers
6. Lasers for Hair Removal 

3
25

101

172

236
252

Section 2: Advanced Laser Interventions
7. Nonablative and Subsurface Rejuvenation

 Step by Step Approach 291
8. Nonsurgical Tightening 
9. Aesthetic Intense Focused Ultrasound (IFUS): Clinical Perspective
on Fitzpatrick Skin Types III–VI
10. Noninvasive Body Contouring
11. Lasers for Scars, Keloids, and Stretch Marks

275
294
319
336
361

Section 3: Practical Aspects and Advances
12.
13.
14.
15.
16.
17.
18.

Miscellaneous Laser Responsive Disorders
How to Start a Laser Practice (Private Setup)
How to Set up a Laser Clinic in a Public Funded Institution
Therapeutic Pearls in Lasers
Medicolegal Aspects of Lasers in Dermatological Practice
Complications and their Management
New Aspects and Controversies in Lasers

379
416
421
432
441
455
471


xviii  Lasers in Dermatological Practice

Appendices
Appendix 1:
Appendix 2:
Appendix 3:
Appendix 4:
Appendix 5:
Appendix 6:
Appendix 7:
Appendix 8:
Appendix 9:

Laser Safety/Eye Care
Consent Form
Procedure Checklist
Postoperative Care
Sample Operative Note
Sample Postoperative Instructions (Ablative Lasers)
Patient Information Sheet
Local Anesthetics

Select Bibliography

Laser and Medical Devices (Index)

493
504
506
507
512
513
514
528
538
541

Index543


Section

Conventional
Laser Interventions

1



Chapter

1

Basics of
Laser-Tissue Interactions
Kabir Sardana, Vijay K Garg, Shivani Bansal,
Jaspriya Sandhu, Twinkle Daulaguphu

Medical lasers have evolved over the years with numerous applications.
Dermatologic laser surgery is regarded as one of the fastest growing areas
in the emerging fields of photomedicine and biomedical optics. As with any
device, the most efficacious and appropriate use requires an understanding
of the basic photobiological and photophysical principles of laser-tissue
interaction as well as the properties of the laser itself. This chapter provides a
brief description of the nature of the laser, how it works, and the fundamental
mechanisms of its interaction with human skin.

Light
Light represents one portion of a much broader electromagnetic spectrum.
Light can be divided into the UV (200–400 nm), VIS (400–700 nm), NIR “I”
(755–810 nm), NIR “II” (940–1,064 nm), MIR (1.3–3 mm), and Far IR (3 mm
and beyond) (Fig. 1.1).
Normally, the percentage of incident light reflected from the skin surface
is determined by the index of refraction difference between the skin surface
(stratum corneum n = 1.55) and air (n = 1). About 4–7% of light is typically
reflected and is called the Fresnel reflectance because it follows Fresnel’s
equations relating reflectance to the angle of incidence, plane of polarization,
and refractive index. The angle between the light beam and the skin surface
determines the percentage of reflected light. More light is reflected at “grazing”
angles of incidence. It follows that, to minimize surface losses, in most laser
applications, one should deliver light approximately perpendicular to the
skin. One can deliberately angle the beam, on the other hand, to decrease

penetration depth and also attenuate the surface fluence by “spreading” the
beam.
On the other hand, the surface of dry skin reflects more light because
of multiple skin-air interfaces (hence the white appearance of a psoriasis
plaque). The light penetration into the epidermis depends on the wavelength dependent absorption and scattering. Because of scattering, much
incident light is remitted (remittance refers to the total light returned to the


4  Lasers in Dermatological Practice

Fig. 1.1: Absorption spectrum of various lasers in
relation to the major chromophores

environment due to multiple scattering in the epidermis and dermis, as well
as the regular reflection from the surface). In laser surgery, light reflected
from the surface is typically “wasted”. This “lost” energy varies from 15% to as
much as 70% depending on the wavelength and the skin type. For example,
for 1,064 nm, 60% of an incident laser beam may be remitted.
Tissue effects occur only when light is absorbed. The absorption
coefficient is defined as the probability per unit path length that a photon at a
particular wavelength will be absorbed and it depends on the concentration
of chromophores (absorbing molecules) present. The three primary skin
chromophores are water, hemoglobin and melanin (Fig. 1.1). Chromophores
exhibit characteristic bands of absorption at certain wavelengths. For
example, melanin absorbs broadly across the visible and ultraviolet (UV)
spectrum, the oxyhemoglobin and reduced hemoglobin in blood exhibit
strong bands in the UV, blue, green and yellow regions. Water has strong
absorption in the infrared (IR) region (Fig. 1.1).
Optical properties of the epidermis and dermis are different. In
pigmented epidermis, melanin absorption is usually the dominant process

over the majority of the optical spectrum (200–1000 nm) (Fig. 1.1). In the
dermis, there is strong, wavelength-dependent scattering by collagen fibers,
which attenuates penetration of light. This scattering varies inversely with
wavelength. Thus as a thumb rule, between 280 nm and 1300 nm, the depth


Basics of Laser-Tissue Interactions  5

of penetration increases with wavelength. Above 1300 nm, penetration
decreases due to the absorption of light by water. The most deeply penetrating
wavelengths are 650–1200 nm, while the least penetrating wavelengths are
within the far-UV and far-IR regions.

Types of Light Devices
Lasers contain four main components, the lasing medium, the excitation
source, feedback apparatus and an output coupler. The amplifier of a laser
is the laser material that can be a solid, a gas, or a liquid. The feedback
mechanism is produced by the resonator, where the light is reflected by two
mirrors so that the photons pass several times through the laser material. The
number of photons within the resonator increases exponentially due to the
stimulated emission (Fig 1.2).
With respect to lasing media, there are diode lasers, solid-state lasers, dye
and gas lasers.
Solid-state lasers include the Nd:YAG laser, Er:YAG laser, alexandrite
laser and the ruby laser. The gas lasers include the carbon dioxide (CO2)
laser, argon ion laser and the excimer lasers, while the diode and dye lasers
are singular in their class.

Light Device Terminology
Basic parameters for light sources are power, time and spot size for continuous

wave lasers and for pulsed sources, the energy per pulse, pulse duration, spot
size, fluence, repetition rate and the total number of pulses (Table 1.1).
At least for most ablative lasers, the effect of the laser beam on human
skin can be affected by any of three variables: power, time and spot size. The
effects of power and time are proportional whereas that of spot size (radius)
is an inverse square. If either the power or time is doubled, fluence increases
by a factor of 2. However, if the spot size is decreased by a factor of 2, fluence
increases by a factor of 4. Doubling the spotsize results in a four-fold reduction
in fluence.

Fig. 1.2: Various output modes of a conventional laser


6  Lasers in Dermatological Practice
Table 1.1 Various terminologies used in lasers
Power P (W)

For Cw lasers

Energy E = (J)

For Cw lasers

Power density W/A (irradiance)
(W/cm2) (A = effective area)

For Cw lasers

Peak power P max (W)

For pulsed lasers

Energy E per pulse (J)

For pulsed lasers

Pulse duration t [fs (10 )
to ms (10−3)]

For pulsed lasers

Energy density E/A (radiant
exposure) (J/cm2) (A = effective area)

For pulsed lasers

−15

Cw: continuous wave, fs: femtosecond, ms: millisecond

Energy: Measured in Joules (J).
Fluence: The amount of energy delivered per unit area is the fluence,
sometimes called the dose or radiant exposure, given in J/cm2
Power: The rate of energy delivery is called power, measured in watts (W).
One watt is one joule per second (W = J/s).
Density: The power delivered per unit area is called the irradiance or power
density, usually given in W/cm2.
Pulse width :Laser exposure duration (called pulse width for pulsed lasers) is
the time over which energy is delivered.
Thus the lasers may be continuous, pulsed, quasi continuous and Q-switched

(Fig. 1.3).
The older lasers had pulse durations that varied from seconds to
milliseconds (0.01s/10-3). Millisecond CO2 lasers are gated lasers but largely
continuous wave in nature. The CO2 laser is a classic example of a continuous
mode laser. Microsecond lasers (0.000001 sec/10-6) are the ideal ultrapulse
lasers. Most Er:YAG lasers are also microsecond lasers. Another example is
that of the PDL where a single or a train of pulses is emitted.
Pseudocontinuous lasers (KTP) have very short pulses of light repeated at
very high repetition rates. Extremely short pulses are achieved by Q-switching.
These nanosecond lasers (0.000000001 s/10–9) are used in pigmented lesions
(Q-switched lasers). Recently picoseconds (0.000000000001 s/10-12) have
been used in tattoos.
Power density: It is a critical parameter, for it often determines the action
mechanism in cutaneous applications. For example, a very low irradiance
emission (typical range of 2–10 mW/cm2) does not heat tissue and is
associated with diagnostic applications, photochemical processes and
biostimulation. On the other extreme, a very short nanosecond (ns) pulse can
generate high peak power densities associated with shock waves and even
plasma formation.


Basics of Laser-Tissue Interactions  7

Fig. 1.3: A figurative depiction of the energy and duration of
lasers based on the pulse width

Spot Size: Another factor is the laser exposure spot size (which greatly affects
the beam strength inside the skin).
Other important factors include aspects of the incident light (convergent,
divergent or diffuse) and the uniformity of irradiance over the exposure area

(spatial beam profile). The pulse profile, that is, the character of the pulse
shapes in time (instantaneous power versus time) also affects the tissue
response.
Operational modes: The Operational modes of lasers are Cw, pulsed as
interrupted radiation (in ms), pulsed free running (in hundreds of ms),
Q-switched (in ns) or mode-locked (in fs).
Continuous wave (Cw) laser may be differentiated from a pulsed laser,
which provides bursts of energy. In the Cw mode, the laser delivers a
continuous beam of light with little or no variation in power output over
time (Fig. 1.3). In Cw operation, laser output is controlled by the physician,
typically by depressing a foot pedal.
Interrupted radiation of a cw laser is done by mechanical or electronic
switching with modification of the pulse length. The pulse frequency is low
to moderate, up to 100 Hz. Flash lamp pumped solid-state lasers in the freerunning mode have pulse lengths of 50 ms up to several hundred micro­
seconds. Pulses of medical dye lasers systems can vary from microseconds
to 50 ms. Superpulse is a term specific to some carbon dioxide lasers that