2015年12月10日 星期四

Light therapy: Laser and IPL



Indications:
l   Vascular lesions
l   Pigmented lesions
l   Hair removal
l   Tattoo removal
l   Resurfacing
l   Skin rejuvenation
l   Leg veins (most products are transdermal)
l   Acne
l   Skin tightening
l   Fat/body countouring (body sculpting etc. cause lipolysis, not apoptosis, so it’s temporary)

Light therapies
l   Solid state lasers (something solid within the laser, Nd:YAG, Ruby, Alexandrite, YSGG, Erbium, Fiber lasers)
l   IPL (Intense pulsed light, filtered broadband light)
l   Diode lasers (810nm, 940nm)
l   Dye lasers (585nm, 595nm)
l   Gas lasers (CO2, Argon, Krypton)
l   Q-switched lasers (Nanosecond laser, usually for tattoo removal, skin rejuvenation)
l   RF devices

Wavelength/depth and suitability
l   IPL: sun damage, age spots, rosacea, poikiloderma
l   Mid to long wavelength lasers: rosacea, poikiloderma, large pores, fine lines, acne scars
l   Infrared lasers: Fine lines, acne scars, skin laxity, nasolabial folds
l   Ablative: nasolabial folds

IPL
l   Skin chromophores have broad absorption
l   Multiple wavelengths: target multiple chromophores
l   Large spot size (fast treatments)
l   Versatility
l   Challenges:
n   Light is generated in the hand piece
n   Wavelength band rather than monochromatic (potentially lower selectivity and less depth control than lasers)
n   Large spot size (more difficult to target small lesions)
n   Pulse format and calibration variability
n   IPL makes melasma worse.

Laser
l   Coherent (in-phase)
l   Collimated (non-divergent, can be tightly focused to locally intensify effect)
l   Monochromatic (allows selective targeting of specific absorbing structures)

Desirable response:
l   Heat should be generated where we need it
l   Desired response
l   Sufficient light reaches target
l   Light absorbed by target
l   Absorbed light converts to heat
l   Sufficient temperature rise in target
l   Minimal heating of surrounding tissue

Targets for selective photothermolysis:
l   A chromophore is a light-absorbing component that converts light to heat
l   3 primary chromophores
l   Melanin
l   Haemoglobin
l   Water (throughout skin, used for bulk heating eg. In photorejuvenation)

Challenges:
l   Treatment is determined by target chromophore
l   Melanin absorbs all visible wavelengths well

Be aware of the following false hair removal claim: “The diode/IPL/Alex can also treat all skin types.”

Wavelength: depth of penetration
Wavelength determines absorption target
Wavelength affects light scattering (spread)
Scatter and absorption limit depth of heating

Weakness of high absorption
Limits penetration depth into tissue (difficult to treat deeper vessels)
Prevents uniform heating through larger vessels (preferential heating only in crescents at the tops of larger diameter vessels)

Thermal relaxation time: the time necessary for the target to cool down 50%, through the transfer of its heat to surrounding tissue via thermal diffusion

Pulse duration matched to target
Larger targets retain heat longer
Smaller targets require shorter pulses
0.3-10msec: IPL. 15-30msec: laser

Visible vs Infrared energy
l   Visible (KTP, PDL, IPL)
n   High absorption = low energy
n   Small targets absorb all the light – limited penetration
n   Small targets heat best (face)
n   Increase energy to treat larger targets
l   Infrared
n   Lower absorption = higher energy
n   Light penetrates to heat all of larger vessels
n   Larger targets have more absorption and heat better (leg veins)
n   Increase energy for small targets (face)

Cooling
l   Helps protect the epidermis by decreasing epidermal temperature
l   Pre, parallel and post cooling
l   Pre-cooling is the most significant cooling factor (the colder the starting temperature, the more it has to be heated by the laser to reach unwanted temperatures)
l   Parallel cooling
l   Post-cooling removes any final heat and helps prevent heat bloom from lower targets (beneficial when treating skin types V-VI)

Cooling mechanisms
l   Copper (cools fastest and can be used for pre post and bulk cooling)
l   Saphhire (cools sufficiently well, but less efficiently than copper)
l   Cryogen spray (spray, very limited depth, hyper cools (-30 to -40oC) and requires the laser pulse to reheat the skin to prevent pigmentary complications from cold, cannot provide significant bulk or post cooling, problematic for dark skin)

Hair removal: Treatment interval every 6-7wks. Only useful when hair at surface. So don’t need to be as frequently as every 4 weeks because hair hasn’t come through yet! Don’t wait too long either, because when it’s in the resting age, hair already detached from the bulb and light won’t heat bulb.
Blood vessel removal: Treatment interval every 7-10 days. Maximum 5% overlap. Avoid rigorous activity afterwards because it will just increase blood flow and vessels open again.
Pigmentation and vascularization: ongoing treatments as we will never get rid of the cause


Fractionated laser

Mechanism of action:
l   Works on a fraction of the skin, not removing epidermis.
l   Similar to skin needling, just using laser to cut instead. More heat than needling. Heat makes collagenesis happen faster.
l   We use Clear + brilliant. Fraxel is more ablative than this.
l   Measurable results w/ little downtime
l   Collagen remodeling without pain
l   To slow signs of aging
l   More than offered from chemical peels and MDA
l   Results now before they are ready for corrective laser resurfacing

Benefits:
l   Proactive treatment
l   Maintain what they love
l   Affordable
l   Quick with minimal discomfort (doesn’t always need local anaesthetic)
l   Little to no downtime (redness 1-2 days, dry and flakey approx 1wk)
l   Enhanced skin care continuum
l   Can be up to $700 per session, $200 per session

Beauty treatment step ups:
1.          At home
2.          Facials, peels
3.          Injectables
4.          Clear + brilliant
5.          Transformative procedure
6.          Surgery

Clear + brilliant:
Officially launched May 2011.
1440nm diode laser. Works into the dermis of the skin. Collagen remodeling.
1927nm diode laser: epidermis, for pigment.
Intelligent optical tracking system: only fires when hand piece scanner senses contact w/ skin and proper hand piece movement &velocity.

Prevent/Address early sign of aging skin
Maintain younger looking skin

Minimal superficial disruption: fast healing, less downtime
Targeted penetration: superficial treatment, targets tone and texture for an improved appearance.

Original hand piece (1440nm): deeper narrower penetration for collagen remodeling. Prevent, maintain, texture, minimised pore appearance. Treats only 9% of the total skin area maximum.
Permea hand piece (1927nm): improve tone and radiance, focused on visibly illuminated skin, even uniform tone, enhanced skin permeability, laser followed by topical skincare regime. Wider shallower lesions, with optimal heat concentration on skin surface. More about pigments, but not for collagen remodeling. Maintain, improve, tone, radiance, permeability. Treats only 10% of the total skin area maximum. 

Indication: All skin types, all ages. Low risk treatment for darker Fitzpatricks.
Treat every 4 weeks. If Fitzpatrick 4+ every 6 weeks at lower setting.
Contraindication: oral retinoids, predisposition to keloid formation or excessive scarring, lesion suspicious for malignancy.
Considerations: predisposition to PIHP, active infection, UV exposure, blood thinners, compromised ability to heal, topical retinoids or retinols, use in combination with fillers/Botox. No studies on cosmetic tattoos, pregnant or nursing mothers or silicone implants.

After treatment:
l   Redness/swelling (resolves within a few days)
l   Heat sensation or “sunburn” feeling (<2hrs after treatment)
l   Slightly darker skin appearance (a few days)
l   Dryness, sandpaper feel (a few days)
l   Skin flaking (begins 3-7 days after treatment)

Potential S/E, complications:
l   Prolonged redness, swelling, blistering, scarring, infections, PIHP, herpes reactivation and acne flare-up.
l   Petechiae: more common with delicate skin, vascular condition
l   Pin point bleeding: if treatments intervals are too close together

Post care
l   Allow skin to heal, bland skin care products, avoid exposure to sunlight, use SPF30+ Vit C-serum 10% or 15%.

Procedure:
1.          Apply local anaesthetic cream to face and clingwrap. Leave for 15minutes. Meanwhile turn the power on for the laser machine.
2.          Insert card into reader.
3.          Ensure correct handle and put tip on.
4.          When local anaesthetic time’s up, remove cream using dry face wipe.
5.          Put goggle over client’s eyes and operator’s eyes.
6.          Clean the first section of treatment using alcohol wipe: the client’s right half of the forehead (down to corner of eye).
7.          Press start * button, go in horizontal or vertical direction, 2 passes on the same spot, and 50% overlap in each treatment area. After finishing in one direction, do it again in the perpendicular direction.
8.          Then left half of the forehead, then right cheek, from outwards working inwards, to the nose and chin. Get client to pull mouth downwards when doing above lip region. Do it again in perpendicular direction. Then left cheek.
9.          At the end of the procedure ask client if she wants ice pack to cool face. If not, then put on the after care products.


IPL rejuvenation (Cutera solera opus machine… $14,000 sapphire tip, so we are warned to be careful in handling the hand piece)






Mechanism of action:
l   The heat destroys the red blood cells and the endothelial cells (cells that form the blood vessels). This can result in permanent destruction, part destruction or temporary destruction of vessels.

Procedure:
1.          After alcohol wipe, put on goggles over client’s eyes and operator’s eyes.
2.          Mark treatment areas: horizontal lines on décolletage, vertical lines on face.
3.          Ensure machine is turned on (turn the key), pedal in right position.
4.          Do the settings (program and fluence).
5.          To test it, press the green button, hold the hand piece low and point it to the floor, count one two, and on three press the foot pedal and blink eyes at the same time. Find the best position to place your foot on the pedal.
6.          Use tongue depressor to put gel on treatment area.
7.          Place hand piece on treatment area lightly, and press foot pedal to beam.
8.          Ask client to press lips when doing mouth area.
9.          Use tongue depressor to cover hair bearing areas and the areas of the nose where part of the hand piece tip is not in contact with skin.
10.      Maximum 5%overlap.
11.      At the end of treatment, wipe gel off, put on aftercare products.

Test patching:
1.          Test patch sides of both cheeks, use program B (target both pigment and vessels). If there’s facial hair have to shave it first. Wipe test patch areas with alcohol wipe. Mark a white line on each cheek for face. Drop by 4J for body and mark a cross on chest with the long end being vertical.
2.          Aim to achieve bit of micro crusting when they come back in two days’ time. Brown rectangle/blister/prolonged swelling is overtreatment.


Laser hair removal




Mechanism of action:
l   There is selective photothermolysis of melanin.
l   Melanin in the hair shaft absorbs light energy which becomes heat energy.
l   The hair must be heated to approximately 70ºc to cause protein denaturing. Heat radiates from hair shaft to surrounding follicular cells, causing lysis (death) of some or all of these hair producing cells.
l   The hair follicle is unable to grow a hair or produces a slow growing hair, lighter in colour and smaller in diametre.

Procedure:
1.          Alcohol swab the treatment area.
2.          Shave off hair with razor.
3.          Mark the treatment borders.
4.          Candela GentleYAG laser machine: Place the tip of the laser. Do a test cryo on a black spot to see if it’s spraying properly: should be dispersed evenly, and set treatment parameters according to skin type & chart. Vectus laser machine by Palomar: Auto detect or manually select the skin type. If this is client’s first treatment, drop the settings by 2 joules. Press the start button on screen and on handle to start.
5.          Treat the treatment area in snake like motion. Candela GentleYAG laser machine: with the circle crossing over each other like the Olympic rings. Press the foot pedal to spray. Vectus laser machine by Palomar: 20% overlaps.
6.          At the end of treatment, spray on the cooling spray.


Cosmeceuticals


Note that only the first 4-5 ingredients are the active ingredients. The rest are too negligible in amount to do anything.

Vitamin A
l   Used for:
n   Acne: regulate sebum
n   Brightening effect: has an effect on tyrosinase inhibitor (do not use the term whitening as that is an illegal term to use)
n   Antiaging: increase epithelial turnover, collagen & elastin synthesis
l   How to use: pm only because of photosensitivity, and use alone, don’t put on moisturizer, initially every third night, then increase in frequency up to every night. Can also alternate with other cosmeceuticals.
l   Initial use: redness, flakiness, sensitivity.
l   5 different types:
n   Retinyl and retinyl palmitate: need to convert to retinoic acid once it’s in the skin
n   Retinaldehyde: softer/gentler, for sensitive/reactive skin
l   Contraindicated in pregnant/lactating people

AHA
l   Desquamate: break the bonds of dead skin cells à increase mitosis in basal layerà increased epithelialization/cell turnoverà decongest poresà increase absorption of the actives into the skin
l   How to use: pm only as photosensitivity, 2-3x/week
l   Contraindicated in pregnant/lactating people

Vitamin C (ascorbic acid)
l   Used for:
n   Collagen stimulation
n   Brightening: TI inhibitors
n   Promotes healing
n   Antioxidant: spare electrons that can be donated to free radicals
n   Anti-inflammatory
l   How to use: Can be used am &pm. Don’t put Vit A + C at the same time as theirs is bad interaction. Don’t put AHA + Vit C at the same time as it only produces a duplicating effect.
l   12 types:
n   MAP: most stable and preferred
n   Ascorbyl 6 palmitate
n   VCP-IS-Na
n   Ascorbic acid sulfate
n   Tetraisopalmitoyl ascorbic acid
l   Very unstable molecule, need to be packaged carefully
l   Vit C + zinc on skinà increase sun protection 6x

Vitamin B
l   Used for:
n   Strengthening and healing of skin
n   Increase hydration
n   Decrease transepidermal water loss
n   Decrease pigmentation by preventing transfer of melanin to keratinocyte
n   Suppresses excess oil production
n   Enhances blood flow
l   Types:
n   Niacinamide B3: Synergie has the highest % Niacinamide on market
n   Panthenol B5

Chirally correct treatments, eg. L-vitamin C. 20%
Chemical sunscreen needs to be on skin 20minutes before sun exposure, whereas zinc works straight away.
Aspect (blue label) can be stocked in beauty clinics without prescribing doctor.
Aspect Dr (red label) has to be stocked in beauty clinics with prescribing doctors.


Skin needling


Mechanism of action:
The microneedles penetrate through the epidermis but do not remove it; the epidermis is only punctured and heals rapidly. The needles seem to separate the cells from each other rather than cut through them, and thus many cells are spared. When a needle penetrates into the skin, the injury causes localized damage and minor bleeding by rupturing fine blood vessels. A completely different picture emerges when thousands of fine needle pricks are placed close to each other. Most authors consider that skin needling induces normal wound healing. Recently, a new hypothesis has been proposed to explain the PCI mechanism of action: when CIT is performed using a high-quality device, the fine microneedles do not create a wound in the classic sense. The wound healing process is cut short, as the body is somehow ‘fooled’ into believing that an injury has occurred. According to this new theory, bioelectricity (also called ‘demarcation current’) triggers a cascade of growth factors that stimulate the healing phase. Although the mechanism of action is still unclear, the final result is deposition of new collagen in the upper dermis.

Depth:
l   Home skin needling: 0.2-1mm
l   Beauty/clinical: 1-1.5mm
l   Medical: 1.5-3mm

Indications:
l   Best form of treatment for melasma.
l   Pigmentation
l   Uneven skin
l   Acne, rosacea
l   Stretch marks
l   Can be done during pregnancy if no anaesthetic is used. Further down the track of pregnancy, do shallower depth as pregnant ladies bleed more easily.
l   Because it puts a controlled wound through the epidermis into dermis, there is low risk of PIHP and short down time.

Contraindications:
l   Infection
l   Pregnancy, lactation (if local anaesthetics is being used)
l   Heart conditions
l   Blood thinners (fish oil is still ok)

Treatment regime:
6 sessions, every 6 weeks. If concern is about pigmentation then ongoing.

Procedure:
1.          Double glove.
2.          After face is cleaned, put on topical anaesthetic + cling wrap and leave on for 45 minutes.
3.          When time is up, wipe off with face wipe, then clean with chlorhexidine.
4.          Wipe down the dermapen and screw on the needle.
5.          Put on hyaluronic acid gel (or PRP platelet rich plasma for even better effect) to hydrate the skin treatment area.
6.          Treat in cross hatching technique: 4 directions (horizontal, vertical, diagonal), 50% overlapping.
7.          Forehead: 0.25-0.5mm, depending on how meaty the forehead is.
8.          Nose: 0.5mm.
9.          Under eyes: 0.25mm (just 1-2 strokes under eye, following orbit to get the crow feet too)
10.      The rest of the face: 1.5mm.

A journalist's personal experience with Dermpen:
http://www.smh.com.au/lifestyle/beauty/is-it-worth-it-this-week-the-dermapen-20140326-35jjw.html