Lasers used in published reports include the pulsed dye 585–595 nm, copper vapor 511 nm, krypton 520–530 nm, frequency-doubled Q-switched neodymium : yttrium aluminum garnet Nd:YAG 532 n
Trang 1with the potential for some degree of correction.
Although the amount of correction is variable and, at
times, limited, many patients cannot afford or are
unwilling to spend 2–3 weeks recovering from a surgical
procedure.These two devices, therefore, offer
alterna-tives to traditional lifting procedures when patients
can not afford the downtime and are willing to accept
a lesser degree of lifting
The area of noninvasive skin tightening is still
rela-tively new, and we, as operators, are still learning how
to maximize our results Certainly, the future will
bring us further technological advancements and other
new devices that will enhance our ability to perform
less-invasive and noninvasive rejuvenation
REFERENCES
1 Alster TS, Garg S Treatment of facial rhytides with a
high-energy pulsed carbon dioxide laser Plast Reconstr Surg 1996;98:791–4.
2 Khatri KA, Ross EV, Grevelink JM, et al Comparison of
erbium:YAG and carbon dioxide lasers in resurfacing of facial rhytides Arch Dermatol 1999;135:391–7.
3 Lennox G Shrinkage of collagen Biochim Biophys Acta
1949;3:170–87.
4 Ross EV, Naseef GS, McKinlay JR, et al Comparison of
carbon dioxide laser, erbium:YAG laser, dermabrasion, and dermatome: a study of thermal damage, wound contraction, and wound healing in a live pig model:
implications for skin resurfacing J Am Acad Dermatol 2000;42:92–105.
5 Tunnel JW, Pham L, Stern RA, et al Mathematical
model of nonablative RF heating of skin Lasers Surg Med 2002;14(Suppl):318.
6 Hsu TS, Kaminer MS The use of nonablative quency technology to tighten the lower face and neck Semin Cutan Med Surg 2003;22:115–23.
radiofre-7 Fitzpatrick R, Geronemus R, Goldberg D, et al Multicenter study of noninvasive radiofrequency for peri- orbital tissue tightening Lasers Surg Med 2003;33: 232–42.
8 Ruiz-Esparza J, Gomez JB The medical face life: a invasive, nonsurgical approach to tissue tightening in the facial skin using nonablative radiofrequency Dermatol Surg 2003;29:325–32.
non-9 Alster TS, Tanzi E Improvement of neck and cheek laxity with a non-ablative radiofrequency device: a lifting experience Dermatol Surg 2004;30:503–7.
10 Fisher GH, Jacobson LG, Bernstein LJ, et al Nonablative radiofrequency treatment of facial laxity Dermatol Surg 2005;31:1237–41.
11 Koch RJ Radiofrequency nonablative tissue tightening Facial Plast Surg Clin North Am 2004;12:339–46.
12 Nahm WK, Su TT, Rotunda AM, et al Objective changes
in brow position, superior palpebral crease, peak angle of the eyebrow, and jowl surface area after volumetric radiofrequency treatments to half of the face Dermatol Surg 2004;30:922–8.
13 Kilmer SL A new nonablative radiofrequency device: preliminary results In: Arndt KA, Dover JS, eds Controversies and Conversations in Cutaneous Laser Surgery Chicago: American Medical Association Press, 2002:93–4.
14 Ruiz-Esparza J, Shine R, Spooner GJR Immediate skin contraction induced by near painless, low fluence irradia- tion by a new infrared device: a report of 25 patients Dermatol Surg 2006;32:601–10.
15 Zelickson B, Ross V, Kist D, et al Ultrastructural effects
of Titan infrared handpiece on forehead and abdominal skin Dermatol Surg 2006;327:897–901.
Trang 2Cumulative exposure to the sun can induce clinical and
histological changes in the skin, commonly called
photo-aging or dermatoheliosis This occurs primarily in
patients with fair skin types (Fitzpatrick 1 to Fitzpatrick
3 skin types) who have experienced repeated solar
injuries over the years, such as lifeguards and outdoor
laborers.1Clinically, photoaging represents a polymorphic
response to sun damage that manifests variably as
wrin-kles, skin roughness and xerosis, irregular mottled
pig-mentation, telangiectasias (poikiloderma of Civatte),
actinic purpura, sallowness (also known as Milian
citrine skin), and brown macules or solar lentigines
Besides fair skin, other risk factors for the development
of photoaging include difficulty in tanning, ease of
sun-burning, a history of sunburn before the age of 20,
advancing age, smoking, male gender, and living in areas
with high ultraviolet (uv) radiation (high altitudes).2
Individuals who develop photoaging often have a
genetic susceptibility to photodamage and can
experi-ence sufficient actinic damage to develop skin cancers
such as basal cell cancer or melanoma
The areas primarily affected by photoaging include
the face, the V area of the neck and chest, the back and
sides of the neck, the backs of the hands and extensor
arms, and, in women, the skin between the knees and
ankles Photodamaged skin typically appears
attenu-ated, atrophic, scaly, wrinkled, leathery, and, in some
cases, furrowed and ‘cigarette paper-like’ In persons
of Celtic ancestry, photoaging can produce profound
epidermal atrophy without wrinkling, making the skin
appear almost translucent and making dermal
struc-tures such as blood vessels more visible
Because of its predilection for visible parts of thebody, photoaging-induced pigmentation can have sig-nificant psychosocial impact on affected individuals.Unfortunately, treatment of such pigment alterationshas been difficult Each year, millions of dollars arespent by consumers seeking ‘quick-fix’ solutions forthe cutaneous stigmata of aging In 2002, more than 5million nonsurgical and 1.5 million surgical cosmeticprocedures costing more than $13 billion were per-formed in the USA.3We can only expect such num-bers to increase in the coming decades as our agingpopulation expands, given increases in life expectancyand growing consumer demand for improvements incosmetic appearance
While photoprotection with either chemical orphysical sunscreens remains the mainstay of care forpatients with photoaging-induced pigmentation, addi-tional topical treatments in the form of retinoids,steroids, chemical bleaches such as hydroquinone,hydroxy acids, and chemical peels are also available.Unfortunately, many of these topical treatments areonly able to affect changes at the level of the epider-mis, while most textural and tinctorial changes in sun-damaged skin are caused by alterations in structures inthe upper and deep dermis
The introduction of laser and visible-light ogy over the past 30 years has revolutionized ourunderstanding and treatment of photoinduced pig-mentation by more selectively targeting pigmentedmolecules and structures in the dermis without dam-aging the overlying epidermis They have also provenuseful in more directed treatment of epidermal pig-mentation In this chapter, we will review some ofthe more common pigmented lesions associated with
technol-David H Ciocon and Cameron K Rokhsar
Trang 3photoaging as well as the most current and effective
laser modalities available for their treatment
SOLAR LENTIGINES
Solar lentigines are the most common of pigmented
lesions induced by photoaging.4 They are macular,
hyperpigmented lesions ranging in size from a few
mil-limeters to more than a centimeter in diameter They
tend to be multiple and grouped and bear a predilection
for sun-exposed surfaces, including the face, neck,
hands, and forearms Alternative names for solar
lentig-ines include actinic lentiglentig-ines, liver spots, age spots, and
sunspots As with photoaging, the incidence of solar
lentigines increases with time, affecting more than 90%
of Caucasians older than 50 years.When evaluating
indi-viduals with suspected solar lentigines, clinicians must
take care in distinguishing them from ephelides, lentigo
simplex, pigmented actinic keratoses, flat seborrheic
keratoses, melanocytic nevi, and malignant melanoma
While they can be usually differentiated on the basis of
history and clinical appearance, some cases may warrant
a biopsy
Although numerous non-laser therapies have been
shown to be effective for solar lentigines, including
retinoic acid, mequinol, and cryotherapy, many of them
require repeat applications over extended periods of
time to achieve significant cosmetic improvement In
addition, lightening with topical treatment is usually
temporary and incomplete, with the lesions recurring
immediately following cessation of therapy.The primary
advantage of laser treatment of solar lentigines is that
most can be removed completely in one to three
treat-ments, depending on the modality, which provides
patients with more immediate satisfaction
The primary target in a solar lentigo is the pigment
melanin Because of the broad absorption spectrum of
melanin, which ranges from 351 to 1064 nm, various
lasers have been used to treat solar lentigines, most
with excellent results Lasers used in published
reports include the pulsed dye (585–595 nm), copper
vapor (511 nm), krypton (520–530 nm),
frequency-doubled Q-switched neodymium : yttrium aluminum
garnet (Nd:YAG) (532 nm), Q-switched ruby
(694 nm), switched alexandrite (755 nm),
Q-switched Nd:YAG (1064 nm), carbon dioxide (CO2)
(10 600 nm), and argon (488–630 nm) lasers.4For the
purpose of this review, we will concentrate on threelaser modalities widely regarded as the safest and mosteffective for the treatment of solar lentigines: the Q-switched ruby laser, the Q-switched alexandrite laser,and the Q-switched Nd:YAG laser
The Q-switched ruby laser (QSRL) was developed
to emit light in very short pulses that is preferentiallyabsorbed by melanin, thereby reducing damage toother skin structures Q-switched lasers can induceboth photothermal and photomechanical reactions.These lasers generate high-energy radiation that leads
to a rapid rise in temperature (1000°C), resulting inevaporation of targeted pigments within the skin andvacuolization (photothermal damage) The collapse
of the temperature gradient that is created betweenthe target tissue and the surrounding tissue alsocauses fragmentation of the target (photomechanicaldamage)
The use of the QSRL for the treatment of solarlentigines was described in a study of eight womenwith 196 solar lentigines on their forearms.5Therapywas delivered as a single brief pulse of 40 ns to a 4 mm2
area A single course of treatment resulted in fading ofthe lesions without scarring and no recurrence within
a 6- to 8-week follow-up period Histopathologicalexamination of biopsy specimens showed vacuo-lization of superficial pigmentation to a maximumdepth of 0.6 mm immediately after treatment Immuno-histochemical examination of specimens stained withanti-melanocyte-specific antibodies did not indicateremaining melanocytic structures in moderatelypigmented lesions
Another Q-switched laser that has been also shown
to be effective for lentigines is the Q-switchedNd:YAG (QSNd:YAG) laser at 532 nm A three-centertrial evaluated the effectiveness of the frequency-doubled QSNd:YAG laser (532 nm, 2.0 mm spot size,
10 ns) in removing benign epidermal pigmentedlesions with a single treatment Forty-nine patientswere treated for 37 lentigines.6Treatment areas weredivided into four quadrants, irradiated with fluences of
2, 3, 4, or 5 J/cm2and evaluated at 1- and 3-monthintervals following treatment For lentigines, responsewas dose-dependent, with greater than 75% pigmentremoval achieved in 60% of those lesions treated
at higher energy fluences Although mild, transienterythema, hypopigmentation, and hyperpigmentationwere noted in several patients, they all resolved
Trang 4spontaneously within 3 months No other textural
changes or scarring were noted
In a subsequent study the safety and efficacy of
the QSRL at 694 nm and the frequency-doubled
QSNd:YAG (1064 and 532 nm) lasers were compared.7
Twenty patients with pigmented lesions (including
lentigines, café-au-lait macules, nevus of Ota, nevus
spilus, Becker’s nevus, postinflammatory
hyperpig-mentation, and melasma) were treated with the QSRL
and the frequency-doubled QSNd:YAG lasers Clinical
lightening of the lesion was assessed 1 month after a
single treatment A minimum of 30% lightening was
achieved in all patients after only one treatment with
either the QSRL or the frequency-doubled QSNd:YAG
laser The QSRL seems to provide a slightly better
treatment response than the QSNd:YAG laser
Furthermore, most patients found the QSRL to be
more painful during treatment, but the QSNd:YAG
laser caused more postoperative discomfort Neither
laser caused scarring or textural change of the skin
At present the QSNd:YAG laser at 532 nm is favored
by many clinicians for the treatment of lentigines in
light-skinned individuals, while the QSNd:YAG at
1064 nm is favored for individuals with darker skin
types.8 One study has recently reported the use of
the Nd:YAG laser in medium skin types such as Asian
skin Chan et al9compared the clinical efficacy and
the adverse event profile of three different lasers: the
Versapulse Q-switched (VQS) Nd:YAG at 532 nm, the
Versapulse long-pulse (VLP) Nd:YAG laser at 532 nm,
and a conventional QSNd:YAG laser at 532 nm
(Medlite, Continuum Biomedical, Livermore, CA)
The VLP, unlike the VQS laser, causes tissue tion purely through photothermal effects Thirty-fourChinese patients with 68 solar lentigines on the facewere treated with one of the three lasers For the VLPlaser, the spot diameter was 2 mm, with a pulse dura-tion of 2 ms and fluence of 9–12 J/cm2 For the VQSlaser, the spot size was 3–4 mm with a fluence of1.0–1.5 J/cm2 The Medlite laser system involved aspot size of 2 mm, with a fluence of 0.9–1.0 J/cm2.The mean scores (maximum 10) for the degree ofclearing achieved using both patients’ and clinicians’assessments were 4.751, 4.503, and 4.78 for theMedlite, VQS, and VLP lasers, respectively, indicating
destruc-no difference in efficacy
Our treatment of choice is the use of the Q-switchedalexandrite laser (755 nm), as it removes pigmentationeffectively without the purpura commonly associatedwith the use of the QSNd:YAG at 532 nm (Fig 10.1).With the alexandrite crystal, the laser wavelength is
755 nm, which is longer than that of the ruby laser(694 nm) and the QSNd:YAG laser at 532 nm Longerwavelengths penetrate more deeply into the dermisand are absorbed less readily by epidermal melanin Ifthe skin is irradiated with wavelengths in the400–600 nm range, oxyhemoglobin will competestrongly with melanin for absorption of photons, andvascular damage will occur, resulting in purpura.Withlonger wavelengths (> 600 nm), where absorption byoxyhemoglobin is substantially reduced or absent andabsorption by melanin over blood pigments dominates,damage is restricted to the melanin pigment-ladenstructures (Fig 10.2) In a study by Jang et al,10
Fig 10.1 Removal of solar lentigines on the face of a patient with type IV skin after treatment with one session of the
Q-Switched Alexandrite laser (Candela Corporation)
Trang 5197 patients with freckles were treated with the
Q-switched alexandrite laser at 8-week intervals and
clinically analyzed The Q-switched alexandrite laser
was operated at 755 nm, with a pulse width of 100 ns
using a 3 mm spot.After a single treatment, all the
irra-diated freckles in 64% of patients were graded as
excel-lent More than 76% removal of freckles required an
average of 1.5 treatment sessions with 7.0 J/cm2 No
scarring, long-standing pigment changes, or textural
changes were seen
The superiority of laser therapy over cryotherapy in
the treatment of solar lentigines has been well
described Todd et al11have reported a comparative
study of the frequency-doubled QSNd:YAG laser
(532 nm), the HGM K1 krypton laser (521 nm) (HGM
Medical Systems Inc., Salt Lake City, UT), the DioLite
532 nm diode-pumped vanadate laser (Index Corp.,
Mountain View, CA), and cryotherapy A total of 27
patients with a minimum of six lesions on the backs of
their hands were enrolled in the study Each hand was
divided into four sectors, and one treatment was
applied per sector.Treatment with the
frequency-dou-bled QSNd:YAG laser involved treatment for 30 ns to
a 3 mm spot; comparative treatments with the HGM
K1 krypton laser and the DioLite 532 nm
diode-pumped vanadate laser were 0.2 s on/0.2 s off to a
1mm spot and 39 ms to a 1 mm spot, respectively
At 6 weeks after treatment, the frequency-doubledQSNd:YAG laser was found to provide superiorlightening compared with other treatments Thislevel of response was still maintained at 12-weekfollow-up From the patients’ perspective, a surveyshowed that they considered this form of laser ther-apy to produce the best results (n=18), followed bydiode-pumped vanadate laser (n=6), cryotherapy(n=2), and the krypton laser (n= 1) The fewestadverse events were reported from use of the Q-switched laser, whereas the krypton laser had thehighest number of such events Mild transient ery-thema was reported for all therapies, with hypopig-mentation and/or hyperpigmentation and scarringoccurring infrequently
Intense pulsed light systems (IPLs) have been alsoshown to be effective for the treatment of solar lentig-ines – although less so compared with Q-switchedlasers.8IPLs emit broadband light containing multiplewavelengths Using various filters to include or excludeparticular wavelengths, one can target various struc-tures in the skin, depending on the wavelength emit-ted Like Q-switched lasers, IPLs are also based on theprinciple of selective photothermolysis However, IPLsare typically less predictable than Q-switched lasers,due to the wider range of wavelengths being used.Most often, the removal of lentigines by the IPL isincomplete and is an added benefit that occurs duringIPL facial photorejuvenation to correct mild wrinkles,poor skin texture, and telangiectasias associated withchronic sunlight exposure Because light from the IPLmust pass through the epidermis in order to reach thedermal fibroblasts in photorejuvenation, focal melanindeposits that cause lentigines are inadvertently treated
as well Once photothermolyzed, these lesions usuallyturn a dark brown color and then peel off in 7–10 days.Because the wrinkle-improvement aspect of IPL gener-ally takes 6–8 weeks to be seen, and is mild at best,much of the early patient enthusiasm for IPL stemsfrom the eradication of solar lentigines and improve-ment of telangiectasias (Fig 10.3)
For those individuals seeking to improve tion as well as fine, moderate, and deep rhytides onthe face, ablative resurfacing with the CO2 laser(10 600 nm) or Er-YAG laser (2940 nm) remains thegold standard (Fig 10.4) The chromophore for bothlasers is water The CO and erbium lasers operate by
pigmenta-Fig 10.2 5 days post treatment of lentigines on hands
with the Q-Switched Alexandrite laser (Candela
Corporation).Typically, crusting is seen, without purpura
The crusted areas typically peel off within 7–10 days
Trang 6vaporizing epidermal and dermal tissue The depth of
vaporization depends on the device and number of
passes, but in general, in the most aggressive ablative
resurfacing procedures, one does not ablate more than
400µm of skin One can reverse the pigmentation
associated with photoaging rather effectively with
ablative resurfacing, with outstanding results not only
in pigmentation and lentigines, but also in deep linesand furrows One also sees a degree of tissue tighten-ing unparalleled with other laser devices The down-side is the potential risk for scarring and pigmentaryalteration, which in the worse-case scenario can be
Fig 10.3 Improvement intelangiectasias and
pigmentation associated withphotodamage following threetreatment sessions with anintense pulse light (IPL)source: (a) before; (b) aftertreatment (Photographscourtesy of ElizabethRostan,MD.)
Fig 10.4 Significantreduction in pigmentationand rhytids associated withchronic photodamage after
a three-pass resurfacingprocedure with theUltrapulse CO2laser
Trang 7permanent as the raw skin heals It is important to
note that the erbium laser can also be used
superfi-cially, with little downtime or erythema However,
these so called ‘microlaser peels’ have very little effect
on pigmentation
The newest technology for the improvement of
solar lentigines is fractional resurfacing with the Fraxel
laser (Reliant Technologies, Mountain View, CA) This
is a new concept in laser resurfacing whereby the skin
is resurfaced fractionally (15–30%) in one session.12,13
This is accomplished by the placement of an array of
numerous microscopic zones of thermal damage in the
epidermis and dermis, surrounded by islands of
nor-mal tissue The nornor-mal skin left untreated serves as a
reservoir for healing, allowing the skin to heal rapidly
This procedure is typically repeated four to six
ses-sions every 2–4 weeks In this way, one can resurface a
large portion of the skin over time
Unlike CO2or erbium laser resurfacing, the skin
is not vaporized during fractional resurfacing, and
therefore there are no full-thickness wounds Rather,
the skin is photocoagulated These photocoagulatedzones of thermal damage range from 80 to 150µm indiameter and from 300 to 900µm in depth, depending
on the parameters utilized (Fig 10.5).The percentage
of the skin resurfaced at one time depends on the bination of energy and final densities used In four tosix treatment sessions, one can resurface 59–84% ofthe skin at a setting that resurfaces 20% of the skin
com-at a time, and 76–88% com-at a setting thcom-at resurfaces 30%
at a time The photocoagulated epidermis, which isreferred to as MEND (microscopic epidermal necroticdebris), is extruded 3–5 days after the procedure; this
is clinically manifested as first bronzing of the skin andlater as fine flaking The columns of photocoagulatedcollagen in the dermis serve as a stimulus for produc-tion of new collagen One can thus achieve both epi-dermal and dermal remodeling over time (Fig 10.6).The advantages to this fractional approach to resur-facing are numerous, from both a theoretical and apractical perspective First and foremost, patients
do not have open wounds, minimizing downtime.Second, anatomical areas that would generally behighly prone to complications of scarring with tradi-tional resurfacing lasers, such as the neck, chest, andhands, can be safely and aggressively treated Third,potential complications associated with open wounds,such as infection and hyper/hypopigmentation andscarring, are minimized Fourth, one can potentiallytreat deeper dermal pathology Fifth, water is the chro-mophore, so tissue interaction, both in the epidermisand in the dermis, is relatively uniform Traditionally,with combined CO2/erbium laser resurfacing, oneablates tissue approximately 200–400µm during mul-tiple-pass procedures Any deeper treatment risks thecomplication of scarring.With Fraxel laser treatment,one can penetrate tissue much deeper safely, as entireepidermal and dermal ablation is not achieved Thediameter of each column of coagulated tissue is smallenough to be invisible to the unaided eye and is sur-rounded by untreated skin, which provides a tremen-dous reservoir for healing Because of these two factors,tissue can be coagulated within this small column asdeep as 900µm safely With the second-generationFraxel laser (Fraxel SR 1500) employing a variablespot size, penetration as deep as 1.1 mm is possible.The coagulated epidermis is replaced within 24 hours
by an influx of cells from the periphery of the treatedspot, or column
100 µm
Microscopic epidermal necrotic debris (MEND)
Controlled zones of denatured collagen in the dermis
Fig 10.5 Histological evaluation after fractional
resurfacing with the Fraxel laser.The coagulated epidermis is
referred to as MEND (microscopic epidermal necrotic debris)
The MEND are extruded within a week after the procedure It
is thought that the improvement in pigmentation is related to
the extruded MEND having a high melanin content Below
each MEND is a denatured column of collagen (bluish in
color).These columns serve as a new stimulus for collagen
production
Trang 8The current Fraxel laser is a fiberoptic laser utilizing a
wavelength of 1550 nm.The laser handpiece is equipped
with a so-called intelligent optical tracking device that is
able to calculate the speed of the operator’s hand against a
background blue dye, adjusting for inconsistencies in
hand speed, to place the intended number of microthermal zone
in a given area Other manufacturers have also fractionated
the beams of their devices Palomar manufactures a
device that has a fractionated head allowing for delivery of
fractionated laser spots in a stamping mode A few laser
manufacturers are in the process of fractionating CO2or
erbium laser beams in hope of decreasing the patient
downtime associated with ablative resurfacing while
maintaining its superior results
The Fraxel laser is currently FDA-approved for
treatment of periorbital wrinkles, acne and surgical
scars, skin resurfacing procedures, and dermatological
procedures requiring the coagulation of soft tissue, as
well as photocoagulation of pigmented lesions such as
lentigines and melasma Solar lentigines on the face,
and indeed anywhere on the body, can be treated
Multiple sessions are required It is important to note
that the mechanism of clearance is through nonspecific
resurfacing and is not pigment-specific Therefore,
Q-switched lasers remain the gold standard for treatment
of distinct lentigines Fractional resurfacing is useful in
those individuals who seek improvement of diffuse
pigmentation or additionally seek improvement intexture, wrinkles, and (acne) scars
DERMATOHELIOSIS
Long-term sun exposure results in wrinkled, inelasticskin that reflects a loss of collagen in the mid to upperdermis, with concomitant accumulation of elastoticmaterial.14,15This process is referred to as solar elasto-sis, reflecting these histological changes The elastoticmaterial is derived largely from elastic fibers, stainswith histochemical stains for elastin, and demonstratesmarked increased deposition of the protein fibulin 2and its breakdown products The mechanism behindcollagen loss in photodamaged skin may be the upreg-ulation of matrix-degrading metalloproteinases such
as collagenase and gelatinases following UV irradiation
of the skin In addition, UV radiation causes significantloss of procollagen synthesis in the skin.16
Patients with dermatoheliosis present with an all sallow, wrinkled complexion Unfortunately, fewtopical regimens are effective in treating this condi-tion because the pathology lies in the mid to upperdermis Fortunately, various light-based technologiesare available to help improve the appearance ofpatients with this common condition
over-Fig 10.6 Improvement in pigmentation, actinic keratosis and rhytides after fractional resurfacing with four session of theFraxel laser: (a) before; (b) after treatment
Trang 9The gold standard for treatment of solar elastosis
on the face remains ablative resurfacing with CO2
or erbium lasers Tissue is vaporized from 200 to
400µm As the raw skin heals, a wound healing
cas-cade is initiated in which inflammatory cells recruit
dermal fibroblasts to produce new dermal collagen
This process results in an improvement of wrinkles
associated with photoaging (Fig 10.7) Both deep
lines and pigmentation associated with photoaging can
be drastically improved with this procedure Thepotential risks are infection, scarring, and hyper/hypopigmentation, which can at times be delayed
As mentioned above, fractional resurfacing with theFraxel laser has been promising in the treatment offine wrinkles, texture and dermatoheliosis Fractionalresurfacing treats photodamaged skin by targeting only
a small fraction of the skin surface in each treatmentsession Photodamage to the face (Fig 10.8), neck,
Fig 10.7 Significant reduction in wrinkles associated with chronic sun damage after a multipass resurfacing procedure withthe Ultrapulse CO2laser: (a) before treatment; (b) at 6 months’ follow-up
Fig 10.8 Reduction in pigmentation and fine lines after resurfacing with five sessions with the Fraxel laser: (a) before; (b) after
treatment (Photographs courtesy of Elizabeth Rostan, MD )
Trang 10chest, arms (Fig 10.9), and hands has been treated
successfully, as have acne scars, other scars, and
various types of dyschromia, including melasma This
treatment regimen has produced more significant
improvements in texture, color, and deep lines than are
commonly seen with other nonablative technology In
a study conducted by Rokhsar and Fitzpatrick,13an
improvement of 1.5 was seen in the wrinkle score
following four to six sessions with the Fraxel laser,
utilizing the Fitzpatrick wrinkle score, measuring
wrinkles on a scale of 1–9
Dermal remodeling with IPL has been a source of
renewed interest In a study by Goldberg,17five patients
underwent four sessions of dermal remodeling with an
intense pulsed light source All patients received a
pre-treatment biopsy and a second biopsy 6 months after the
initial treatment Biopsies were evaluated for histological
evidence of new collagen formation 6 months after the
initial treatment.While pretreatment biopsies showed
evidence of solar elastosis, the post-treatment biopsies
showed some degree of superficial papillary dermal
fibrosis, with evidence of an increased number of
fibro-blasts in scattered areas of the dermis Such changes, the
author concluded, were evidence of new dermal
colla-gen formation Recently, investigators have reported
better results by combining IPL with δ-aminolevulinic
acid (ALA) However, it still appears that improvement
in fine lines is subtle at best with IPL treatments
Various other lasers have been shown to inducenonablative dermal collagen remodeling, includingthe 1320 nm Nd:YAG laser, the 1450 nm diode laser,and the 1540 nm Er:glass device However, in reality,the results are often not reproducible – or are subtle
at best Because of their longer wavelengths, theselasers are more deeply penetrating and less damag-ing to the epidermis, while being minimallyabsorbed by melanin They use water as a chro-mophore and are intended to target dermal colla-gen It is generally accepted that this class of lasers isthe least effective in treatment of wrinkles associatedwith photoaging
POIKILODERMA OF CIVATTE
Poikiloderma of Civatte refers to erythema ated with a reticulate pigmentation and telangiec-tasias usually seen on the sides of the neck, loweranterior neck, and the ‘V’ of the chest Civatte firstdescribed the condition in 1923 It is a rathercommon, benign condition affecting the skin Manyconsider it to be a reaction pattern of the skin tocumulative photodamage, since the submental area,shaded by the chin, is typically spared It frequentlypresents in fair-skinned men and women in their mid
associ-to late 30s or early 40s
Fig 10.9 Improvement inpigmentation and texturalabnormalities associatedwith sun damage aftercombination treatment withthe Q-switched alexandritelaser (one session) and theFraxel laser (four sessions):(a) before; (b) after treatment.(Photographs courtesy ofRichard Fitzpatrick MD.)
Trang 11The blue–green argon laser was the first laser system
used for treating poikiloderma of Civatte Although it
offered improvement, this treatment had significant
side-effects, most notably scarring The 532 nm
potas-sium titanyl phosphate (KTP) laser introduced later was
an improvement, although complicated by cases
result-ing in occasional hypopigmentation
Treatment options for poikiloderma of Civatte were
revolutionized with the advent of the pulse dye laser
(PDL).18PDLs were first introduced in 1989, with the
first laser emitting light at 577 nm, coinciding with the
last peak of the oxyhemoglobin absorption spectrum
(418, 542, and 577 nm) Because its target
chro-mophore was hemoglobin, the PDL quickly became the
treatment of choice for vascular lesions, including
telangiectasias, hemangiomas, and portwine stains By
lengthening the wavelength to 585 nm, the PDL
achieved deeper penetration into the dermis without
compromising vascular selectivity Currently available
PDLs emit a wavelength of 585 or 595 nm with longer
pulse durations.Although there is deeper penetration of
energy at 595 nm compared with 585 nm, the
absorp-tion of oxyhemoglobin is less after 585 nm.Therefore to
compensate for this decreased absorption, the 595 nm
PDL requires an additional 20–50% of fluence
compared with 585 nm systems
Because telangiectasias are a prominent feature of
poikiloderma of Civatte, the PDL provides a superior
treatment alternative for this condition In one study,
seven female patients (ages 42–52 years) with
clini-cally typical poikiloderma of Civatte, which they
considered to be causing significant cosmetic
disfig-urement, were treated with a PDL at a wavelength of
585 nm and a pulse duration of 0.45 ms (SPTL-1B;
Candela Corp., Wayland, MA).19All seven patients
were of skin type I or II (i.e., they burnt easily, with
little or no tendency to tan), and in all of them
reticu-late telangiectasia was the most prominent
compo-nent of the condition In all of the patients, a test
patch was treated and reviewed at 3 months
Subsequent treatments were undertaken at intervals
of 3 months.The fluences used were 5.0 J/cm2with a
10 mm beam diameter (five patients) and 7.0 J/cm2
with a 7.0 mm beam diameter (two patients) Topical
anesthesia with EMLA cream or cooling with ice was
used Results were assessed by one of the two authors
and graded as excellent (vascular component of the
lesion not visible), good (partial clearing of 50% ofthe vascular component of the lesion), or poor (novisible change)
Five patients had an excellent result, one had a goodresult, and one had a good result with respect toclearing of the vascular component but an overallunsatisfactory cosmetic result due to scarring andhypopigmentation in the treated area This adverseresult is of some interest, since the test patch did notproduce any scarring or pigment change, and thechanges did not occur until 4 months after the treat-ment This patient had been treated at a fluence of7.0 J/cm2 No other adverse effects were noted – inparticular, no pigment changes
Subsequent studies have attempted to delineate ther the adverse outcomes associated with PDL treat-ment of poikiloderma of Civatte, particularly sinceuniform guidelines for treatment of the condition donot exist In a study by Meijs et al20 eight patients(seven women and one man, mean age 48 years) withpoikiloderma of Civatte were treated with a PDLusing a 585 nm wavelength and a fixed pulse duration
fur-of 0.45µs In all patients, one or two test PDL patcheswere performed and reviewed after 3 months All ofthe patients tolerated the testing without complica-tions Subsequent treatments were undertaken atintervals of 3 months All patients were treated withfluences between 3.5 and 7 J/cm2, using a 7 or 10 mmspot size All had a good result with respect to clearing
of the vascular component Nevertheless, six of them,treated with 5–7 J/cm2, reported severe depigmenta-tion 4–11 months after treatment Two patientstreated with lower fluences (3.5–5.5 J/cm2), how-ever, did not report this depigmentation.Therefore, toavoid depigmentation, the authors recommend usingfluences as low as possible when treating dark-skinnedindividuals for poikiloderma of Civatte with PDL andnot exceeding an upper limit of 5 J/cm2, on a 10 mmspot size
Incomplete clearing of poikiloderma of Civatte istypically a result of poor light penetration depths inblood For example, the light penetration depths inblood at 532 and 585 nm wavelengths are approxi-mately 37 (absorption coefficient approximately
266 cm−1) and 52µm (absorption coefficient imately 191 cm−1), while the ectatic blood vessels ofpoikiloderma of Civatte are approximately 100µm
Trang 12approx-in diameter As a result, large blood vessels cannot be
completely coagulated, resulting in incomplete
clear-ing of poikiloderma of Civatte, even with the PDL A
new high-energy PDL (V-Beam; Candela), capable of
producing higher fluences with larger spot size, is
equipped with a glass slide that is used to physically
displace blood in the skin, allowing the energy to be
preferentially absorbed by melanin Although new,
this laser holds greater promise in the treatment of
pigmentation and telangiectasias associated with
poikiloderma
IPL has also been widely used for the treatment of
poikiloderma.21, 22As IPL covers a broad range of
wave-lengths, it can potentially treat both the vascular and
pigmented components of poikiloderma Usually, three
to five sessions are necessary to achieve optimal results
A potential negative outcome that can be associated
with the use of IPL in the treatment of poikiloderma is
the pin-striping developed by some patients and
associ-ated with the use of the rectangular handpieces of IPL
devices Care must be taken to use the IPL handpiece in
a vertical manner in one session alternating with a
hor-izontal manner in the next to minimize the potential
for pin-striping
Given that one cannot use ablative resurfacing to
reverse signs of photoaging in body areas commonly
affected by poikiloderma, such as the chest and neck,
due to the risk of scarring, fractional resurfacing hasrevolutionized the treatment of poikiloderma (Fig.10.10) Unlike the modalities based on selective pho-tothermolysis, which aim to achieve homogeneousthermal injury in a particular target within the skin,fractional photothermolysis produces an array ofmicroscopic regions of thermal injury surrounded byuninjured dermal tissue Recent clinical studies indi-cate that fractional photothermolysis is effective intreating fine wrinkles and epidermal dyschromia, and
in remodeling acne scars.23, 24Fine rhytides improveover time.The improvement in pigmentation is related
to the concept of MEND formation and extrusion Asmentioned above, this microscopic epidermal necroticdebris refers to a column of photocoagulated epider-mis ranging from 80 to 150µm in diameter, whichsloughs off 3–7 days post treatment MEND has a highmelanin content when examined histologically – a factthat may explain improvement in skin pigmentation.Patients typically need three to five treatment sessionsevery 2–4 weeks Besides the face, common treatmentareas include the neck, chest, and hands One distinc-tion between fractional photothermolysis, IPL, andQ-switched laser technology is that its 1550 nmwavelength laser largely targets tissue water and notmelanin Improvement in pigmentation is a byproduct
of general resurfacing and is not pigment-specific
Fig 10.10 Poikiloderma
of the neck and chest isimproved after five sessionswith the Fraxel laser:
(a) before; (b) after treatment.(Photographs courtesy ofRichard Fitzpatrick MD.)