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centimeter of energy emitted from the laser hand-
piece. The laser fluence may need to be
decreased to protect the epidermis to safely treat
patients with darker skin types compared with
those with lighter skin types. Other helpful strate-
gies in safely treating patient of color include
longer wavelengths, longer pulse durations, and
skin cooling before, during, and/or after the proce-
dure to avoid overheating the epidermis.
4,6
CLASSES OF LASERS
The major classes of lasers include ablative and
nonablative lasers in both nonfractionated and frac-
tionated varieties (
Table 3
). Ablative lasers target
water molecules in the epidermis, causing vapor-
ization of skin cells and retraction of the dermis
with collagen formation. Ablative lasers are more
aggressive and function similar to a skin peel with
prolonged recovery time and higher adverse event
profile.
7
Nonablative lasers preserve the epidermis
and target the dermal tissues to promote collagen
formation. These nonablative treatments are milder
and reduce the adverse event profile and recovery
time. Fractionated lasers are designed to target
microscopic treatment zones, or microthermal
zones (MTZs) to create columns of thermal injury
with adjacent normal skin.
4
This procedure pro-
motes healing and improves skin texture compared
with nonfractionated lasers without the high side-
effect profile of ablative lasers. Radiofrequency re-
surfacing is a nonablative technique that uses a
low temperature to penetrate dermal tissues and
promote collagen healing.
7
There are several op-
tions for laser therapy, and it is important to deter-
mine the expectations of your patient while
balancing the risks and benefits associated with
laser therapy in patient-specific phototypes.
TREATMENT GOALS
Lasers may be considered for a variety of indica-
tions, and the goals of the treatment should reflect
the patient presentation.
Skin Laxity
There is an increased desire in all patients to
achieve more youthful and refreshed facial skin.
Over time, facial skin experiences photodamage,
which causes wrinkles, texture changes, and
abnormal pigmentation. Additional changes over
time include soft-tissue volume loss, rhytides,
and increased vascularity. The primary environ-
mental factor that affects aging is ultraviolet radia-
tion, but given the protective effects of melanin and
a thicker epidermis, individuals with dark skin may
experience less skin laxity due to gravity and vol-
ume loss compared with others with fair skin.
4
Dyschromia
The primary concerns of patients may vary
depending on ethnicity and skin type (
Fig. 2
).
Dyschromia is a common presentation of
dark-skinned patients, and it is important to
Table 2
Variables of lasers
Variable
Function
Example
Chromophore Laser target molecule, unique
absorption spectrum and peak
absorption wavelength
Hemoglobin, melanin, water
Wavelength
Property of light measured in
nanometers that influences how
chromophores are targeted
Hemoglobin (variable absorption from
300 nm to infrared)
Melanin (gradually decreasing
absorption from 250 to 1200 nm)
Water (1000 to 1 mm)
Thermal
relaxation
time
Time required for tissue to cool to half
the temperature to which it was
heated
Melanosome (250 ns)
Vessels (2–10 ms)
Hair follicles (100 ms)
Pulse duration Time to heat tissue to target tissue;
choose pulse duration less than or
equal to thermal relaxation time of
target chromophore to avoid
damage to surrounding tissue
Pulse duration 10 to 100 ns to target
melanosome
Energy fluence Joules per square centimeter of energy
emitted by a pulsed laser device
25 J/cm
2
used by a 1064-nm Nd:YAG
for laser hair removal; highest
tolerated fluences are 100 J/cm
2
(skin
types IV, V) and 50 J/cm
2
(skin type VI)
Laser Skin Treatment in Non-Caucasian Patients