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Onze mening: "niet spectaculair"
Wij vinden het niet zo goed werken
op grijs haar, blond haar, en rood haar, ondanks dat onderzoeken
wel soms van goed resultaat getuigen. Als we de hoogste instelling
mochten toepassen, lukte het soms wel de haartjes weg te krijgen
bij 1 op de 20 personen. Zelfs met voorbereiding van een donkermakende
lotion, de lipoxome-lotion, gaat bij de meeste personen maar heel
weinig weg. De haartjes worden eerder wat zachter. We adviseren
bij lichte haren op het gezicht te wachten op meer wetenschappelijker
vooruitgang en ondertussen:
- de donkere haren wel te laten laseren voordat ze grijs worden
- als de meeste haren grijs zijn, dan toch te epileren/ harsen
- electrische epilatie te nemen als het er niet zoveel zijn
White paper
wel positief
Het onderzoek dat we hieronder hebben overgetypt is wel positief.
Locatie: Universiteit van Ottawa. Het onderzoek is gedaan met 16
vrouwelijke vrijwilligers (gemiddelde leeftijd 57) met lichte huidskleur
(type 1, 2, 3). Zij mochten gedurende 1 jaar terugkomen iedere keer
als er weer nieuwe haargroei was op het gezicht.
Normaliter met lichtbehandelingen zoals laser en Intense pulsed
light (IPL) is er geen effect omdat pigment het doel is van deze
technieken, en er geen pigment zit in witte of grijze haren. Maar
met radiofrequency (RF) erbij in de hoogste stand blijkt in dit
onderzoek het wel redelijk te lukken: gemiddeld 40% haarreductie
na iets meer dan 3 behandelingen met pauzes ertussen van gemiddeld
10 weken. Men ging in de zelfde behandeling tot vier keer over dezelfde
huid heen, tenzij roodheid eerder optrad. Er waren geen bijwerkingen.
Het effect wordt in theorie veroorzaakt door
het verschil in geleiding tussen huid en haarschacht. De RF komt
binnen via de haarschacht maar deze heeft een hogere weerstand (impedance)
dan de huid eromheen en dat dwingt de RF te vloeien naar de cellen
rondom de haarschacht en de wortel. Daar wordt een snelle opwarming
bereikt.
Om hetzelfde effect te bereiken met alleen maar IPL of laser zou
een zeer lange puls nodig zijn van 1 seconde. Maar zelfs dat zou
voor wit, grijs, blond en rood haar nog niet werken. Bovendien zou
het zeer pijnlijk zijn. Dus Dr. Laughlin concludeert dat deze RF-techniek
voorlopig de beste oplossing is, misschien op den duur met nog hogere
instellingen van het apparaat, dat valt nog te onderzoeken.
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INTRODUCTION
Photoepilation is an established alternative to electrolysis in
clinical practice. Certain lasers emitting wavelengths in the red
and near infrared area of the electromagnetic spectrum produce varying
degrees of permanent hair loss.
1,2 However, effective removal of unwanted hair
using optical energy is essentially limited to black or dark brown
hair.
Hair color is genetically determined by the presence of the black-brown
pigment eumelanin and the yellow-red pigment pheomelanin. There
is no simple arithmetic relationship between eumelanin / pheomelanin
ratios and hair color but the highest levels of eumelanin occur
in black hair and the highest levels of pheomelanin are associated
with fiery-red hair. Eumelanin absorbs red or infrared light more
than pheomelanin and it is the black-brown pigment granules in the
matrix cells and hair shaft that provide the primary target chromophore.
Predictably, studies confirm that photoepilation is less effective
for red and blond hair. 3,4,5
The development of gray and white hair is related
to partial and finally complete loss of melanicytes. 6 The
virtual absence of a target chromophore explains the failure of
all light-based technology to achieve epilation of gray or white
hairs. 4,7 Radio-frequency (RF) energy can
heat the bulge and outer root sheath of the hair follicle in the
absence of melanin. The thermal effect of RF energy depends on the
electrical properties of the tissue and does not require a chromophore
such as melanin. The heat generated is proportional to the square
of the current density. Each tissue has an impedance or resistance
to the flow of RF current. The greater the impedance the lower the
current density and the amount of heating produced. The hair shaft
is a virtual barrier to the passage of RF current. The shaft diverts
the flow of current and concentrates it in the outer layers of the
hair follicle. The increase in current density within this zone
creates a change in temperature four times higher than in the surrounding
dermis. RF energy has the unique capability to heat the bulge and
outer root sheath directly without any absorption of energy by pigmented
structures within the matrix and hair shaft.
The Aurora DS system delivers a combination of RF and pulsed optical
energy. The energy deposited in the skin from RF energy is independent
of skin colour and there is no epidermal barrier to absorption as
occurs with optical energy. Only part of the heat delivered to the
target comes from optical energy contained in the electromagnetic
pulse. This delivers effective heating and biologic effects at lower
levels of optical energy. the Aurora DS achieves effective epilation
of black or dark brown hair in any skin type with a lower rate of
side effects than light based therapy. It produces thermal effects
on the hair follicle in the absence of melanin and could achieve
effective epilation for gray or white hair.
OBJECTIVE
The purpose of the
study was to determine the efficacy and safety of the Aurora DS
device (Syneron Medical) for epilation in subjects with white hair.
PATIENTS
AND METHODS
Sixteen adult women with white facial hair were enrolled in a longitudinal
study. The mean age at enrollment was 57 years (range 43-83 years).
The group included two patients with skin type I, seven with skin
type II, and seven with skin type III. Twenty-one study sites were
selected. 16 sites were on the chin and 5 sites over the upper lip
or moustache area. All participants were screened to exclude patients
with photosensitivity, diabetes, a history of keloid scarring, or
therapy with retinoids such as Accutane within the past year.
Informed consent was obtained and each study site was mapped. The
area was first shaved leaving residual `stubble' of approximately
1mm. and a photograph taken for the calculation of a baseline hair
count. A baseline hair count was obtained manually by two indipendent
observers marking terminal hairs under 6X magnification with an
apochromatic optical loupe (Nikon). The counts were repeated using
photographic images and the average of the four readings taken.
A close shave of the selectred area was carried out prior to treatment.
No topical or local anesthetic waas employed.
An Aurora DS system delivering RF energy and intense pulsed-light
in an integrated pulse profile was used to perform the study. The
geometric design of the RF electrodes conducts energy through the
skin to a depth of 4 mm. for this study the shortpulse profile mode
was used. This consists of the usual pre-pulse of RF energy followed
by a single 25 millisecond pulse of light delivered within an RF
pulse of energy lasting 200 milliseconds. The optical energy delivered
is a spectrum of light in a waveband from 680-980 nanometers. The
device provides contact epidermal cooling through the hand piece
applicator and maintains skin temperature at around 5 degrees Centigrade.
A transparent water-based gel was used as a contact medium and light
pressure on the applicator during treatment ensured proper coupling
of the electrodes to the skin.
The level of RF energy was set at the maximum
of 20 joules/cm3 for all participants. The range of fluences used
for the study was 24-30 joules/cm2 depending on skin type. Test
pulses were carried out on an area adjacent to the study site to
determine the level of optical energy suitable for each patient.
Pulses were placed in an adjacent minimally-overlapping pattern
over the entire study site using the Aurora DS device. Multiple
passes were carried out to a maximum of four passes unless there
was persistent erythema that lasted more than a few minutes after
each pass was completed.
Participants
were asked to return when regrowth occurred. Repeat treatments were
performed at various intervals and repeat hair counts obtained using
the method described previously. At one year after the study was
commenced, each patient's status was determined by recording the
number of treatments and the last hair count obtained after stable
regrowth had occurred. The percentage hair loss was calculated for
each subject and the average number of treatments required and the
average hair loss for the entire froup determined. The time elapsed
between the last treatment and the time when a repeat hair count
was taken was determined for each patient and the average follow-up
period calculated for alle treatment sites.
RESULTS
For the 21 sites in the 16 participants the average hair los was
40.7% (range 0-85.7) after an average number of 3.4 treatments (range
2-6). The average time between the last treatment and the next hair
count was 10 weeks (range 3-28 weeks). Several participants had
stable hair loss for > 4 months. One patient obtained a 22% loss
at 7 months after a 2nd treatment, another had 37% loss 4,5 months
after the 4th, and another had 37% los 4.5 months after the 4th,
and another a 70% loss 5.25 months after 2 treatments. Figure 1
shows a patient with 85.7% loss of white hairs 6 weeks after the
fifth treatment. There is also hair loss of black hair but only
the counts of white hair are used for the purpose of this study.
There were 3 sites that showed no response but two of these sites
were in participants where 2 sites were treated and the other treatment
site showed hair loss of 25% and 50%. two of these sites had been
treated tweice and the other three times. The areas that were non-responsive
were not site-specific. Of the 3 non-responsive areas two involved
the area over the upper lip and one the chin. There was no correlation
between the degree of hair loss and any factor such as skin type,
age, or caliber of hair. There were no adverse effects or complications
observed in any of the study participants.
foto van
de oorspronkelijke tekst
Figure 1 shows
a patient with 85.7% loss of black and white hairs 6 weeks after
the fifth treatment. |
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DISCUSSION
These results indicate that combined radio-frequency and optical
energy is the first effective method of photoepilation for white
hair. It is generally accepted that white hair is unresponsive to
light systems operating in the red and near infrared spectrum. This
impression is hardly based on a substantial body of evidence from
the published literature as there are only a few reports on the
light based removal of white hair. 4,7 One
study 4 included only two patients with white hair and another report
7 makes the statement that `the current treatment of white hair
produces unsatisfactory results' without providing data. Most clinicians
know from personal experience that photoepilation is ineffective
for white hair and now exclude these patients from studies or treatment.
Electrolysis is presently the standard of care for this type of
patient. A
40 percent hair loss after an average of approximately 3 treatments
suggests that combined radio frequency and optical energy offers
a favorable alternative. With the longitudinal
design of the study, it is reasonable to expect that the level of
hair loss could increase as more study participants receive further
treatments.
There are several possible targets within the hair follicle for
photothermal destruction resulting in permanent hair loss. These
include the area of bulge and its population of stem cells, the
matrix and dermal papilla, the vascular supply of the follicle (particularly
the bulb), and cells comprising the three layers from the inner
through outer root sheath to the connective tissue sheath. It is
likely that different mechanisms of injury are associated with each
particular combination of wavelength and pulse duration. In some
instances permanent hair loss is achieved by miniaturization of
follicle from photothermal destruction of the bulge. With wavelengths
approaching 1064 nanometers, it is possible to destroy structures
within the bulb and the surrounding root sheath. If the damage extends
to the connective tissue sheath, the follicle will be permanently
disabled and appear on histologic section as a fibrous band.
The
extended theory of selective photothermolysis 8
and thermal damage time (TDT) explains that using progressively
longer pulses will widen the zone of thermal damage from melanin
laden structures in the central portion of follicle to the outermost
layers of the root and connective tissue sheath. It argues that
the ideal pulsewidth for photoepilation may be much longer than
the thermal relaxation time of 5 to 90 milliseconds for the average
hair follicle. For pulses in this range there is rapid heating and
vaporization of the hair shaft and matrix, which in most instances
damages the bulge region from diffusion of heat. Thermal damage
to the outer root and connective tissue sheath is likely to be minimal
as there is insufficient time for the thermal damage front to reach
these structutres. Furthermore, conventional long pulses up to 100
milliseconds have relatively hight peak power, which overheat and
vaporize the hair shaft and termintates its abiligy to absorb more
energy.
The TDT varies with the diameters of the hair shaft and follicle,
and the temperature ofthe hair shaft or matrix. Form medium to coarse
hair (50-125 microns) the TDT is 170-1000 milliseconds. Using super
long pulses in this range should be a more efficient way to produce
full thickness damage of the hair follicle. This mechanism of injury
may be advantageous to teat blond or red hair where optical coupling
to lower levels of black-brown granules is diminished. However,
there are very few systems with super long pulses available for
clinical urse. for white hair without pigment for optical coupling,
even a super long pulse is likely to be ineffective.
With
any pulsewidth, optical energy targets melanin and heating of the
hair follicle occurs from the inside and proceeds outwards. In contrast,
RF energy heats the hair follicle from the outside in and requires
no chromophore. This and other photobiologic principles provide
a compelling argument that combined RF and optical energy is an
ideal method for removing whtie or light-colored hair. For gray
or white hair where there is little or no melanin, the optical component
of the electromagnetic pulse plays a minor role. It is likely that
there is some nonspecific preheating of the follicle acting as a
macroscopic structure absorbing light. The preheating reduces the
impedance and facilitates the concentration of RF current within
the outer layers of the follicle. Thermal damage occurs to the areas
of the bulge and outer root sheath and disables the follicle as
heating occurs from the outside in. This mechanism of injury should
also provide effective epilation when the target chromophore is
reduced, as with blond or red hair. For black or dark brown hair
coupling of optical energy to melanin facilitates and plays a greater
role in photothermal injury.
Integrated RF and optical energy (Aurora DS) is approved as an effective
method of photoepilation for black or dark brown hair in all skin
types. Its first advantageo ver systems that use pure optical energy
is the hight therapeutic margin of safety observed when treating
patiens with skin types V and VI. This study suggests that its second
advantage is the distinct ability to remove white hair. Alopecia
persisting in some instances for 4-7 months points to permanence,
since the maximum cycle for facial hair is 4-6 months. It is reasonable
to assume that the Aurora DS disables follicles containing white
hair primarily from the thermal damage induced by the RF component.
One area for future investigation would be to assess whether higher
levels of RF energy are more effective for the epilation of blond,
red or white hair.
References
1. Dierickx CC, Grossman
MC, Farinelli WA, et al. Permanent hair removal by normal-mode ruby
laser. Arch Dermatol 1998; 134:837-842.
2. Laughlin SA, Dudley DK. Long-term hair removal using a 3-millisecond
alexandrite laser. Journal of Cutaneous Medicine and Surgery 2000;
4:83-88.
3. Williams R, Havoonjian H, Isagholian K, Menaker G, Moy R. A clinical
study of hair removal using the long-pulsed ruby laser. Dermatol
Surg 1998; 24:837-842.
4. Bencini P, Luci A, Galimberti M, Ferranti G. Long-term epilation
with long-pulsed Neodimium: YAG laser. Dermatol Surg 1999; 25: 175-178.
5. Lorenz S, Brunnberg S, Landthaler M, Hohenleutner U. Hair removal
with the longpulsed Nd: YAG laser: a prospective study with one
year follow-up. Lasers in Surgery and Medicine 2002; 30: 127-134.
6. Herzberg J, Gused W. Das Ergrauen des Kopfhaares. Arch Klin Exp
Dermatol 1970; 236: 368-384.
7. Ash K, Lord J, Newman J, McDaniel D. Laser hair removal. Hair
removalusing a longpulsed alexandrite laser. Dermatologic Clinics.
1999; 17: 387-399.
8. Altshuler G, Anderson R, Manstein D, Zenzie H, Smirnov N. Extended
theory of selective photothermolysis. Lasers in Surgery and Medicine
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