introduction to laser dermatology 1

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الرحمن الله الرحمن بسم الله بسم الرحيمالرحيم

Yasser A. Hamed M.DYasser A. Hamed M.DAl-Azhar universityAl-Azhar university

Research Associate Minneapolis University Minnesota USAResearch Associate Minneapolis University Minnesota USA lasercairo@yahoo.comlasercairo@yahoo.com

Principles of CoherentPrinciples of Coherent and and

Non-Coherent light therapy.Non-Coherent light therapy.

Yasser A. Hamed M.DYasser A. Hamed M.DAl-Azhar universityAl-Azhar university

Research Associate Minneapolis University Minnesota USAResearch Associate Minneapolis University Minnesota USA lasercairo@yahoo.comlasercairo@yahoo.com

Principles of laser photo-Principles of laser photo-rejuvenation and scar treatment.rejuvenation and scar treatment.

Intense Pulsed Light Intense Pulsed Light (IPL)(IPL)

Is it the future ?Is it the future ?

YYasser asser A.A. HHamed amed M.DM.D

Al-Azhar university Cairo – Egypt.Al-Azhar university Cairo – Egypt.Research Associate Minneapolis Minnesota USAResearch Associate Minneapolis Minnesota USA

lasercairo@yahoo.comlasercairo@yahoo.com

Yasser A. Hamed M.DYasser A. Hamed M.DAl-Azhar universityAl-Azhar university

Research Associate Minneapolis University Minnesota USAResearch Associate Minneapolis University Minnesota USA lasercairo@yahoo.comlasercairo@yahoo.com

Principles of CoherentPrinciples of Coherent and and

Non-Coherent light therapy.Non-Coherent light therapy.

LASER historyLASER history & &

Science fictionScience fiction

LASER as a Science fictionLASER as a Science fiction

Light as a weapon was first mentioned in 1898 in a fiction Light as a weapon was first mentioned in 1898 in a fiction story story “The War of the Worlds”“The War of the Worlds”, written by , written by Herbert George Herbert George Wells (1866 – 1946). Wells (1866 – 1946).

English author English author H. G. WellsH. G. Wells

LASERLASER

It was until 1916 It was until 1916 Albert EinsteinAlbert Einstein (1879–1955) (1879–1955) developed the basic fundamental concepts theories for developed the basic fundamental concepts theories for the development of masers and lasers.the development of masers and lasers.

What is LASER ?What is LASER ?

LASERLASER

Laser is an acronym Laser is an acronym

L L LightLight

A A AmplificationAmplification

S S StimulatedStimulated

E E EmissionEmission

R R RadiationRadiation

Electromagnetic spectrumElectromagnetic spectrumLaser light follows the basic properties of and Laser light follows the basic properties of and electromagnetic radiation.electromagnetic radiation. Light is composed of Light is composed of “Photons”“Photons” propagating in waves. propagating in waves.

Characters of Laser lightCharacters of Laser light

Each electromagnetic wave has a Each electromagnetic wave has a “Wavelength”“Wavelength” = distance = distance between 2 peaks measured in between 2 peaks measured in “nm”“nm”, “, “Amplitude”Amplitude” is the height is the height of one peak and of one peak and “Frequency”“Frequency” which is the number of cycles which is the number of cycles per second per second “hertz”“hertz”

LLASERASER

Characters of Laser lightCharacters of Laser light

MonochromaticMonochromatic waves have the same colorwaves have the same color

CoherentCoherent waves of energy travel through the waves of energy travel through the

space and time in a definite phase in space and time in a definite phase in relationship with one another.relationship with one another.

CollimatedCollimated waves are parallel that can travel a waves are parallel that can travel a long distances without deviation long distances without deviation

Stimulated EmissionStimulated EmissionIn 1953 by American physicists In 1953 by American physicists Charles H. Townes Charles H. Townes andand A. L. Schawlow A. L. Schawlow,, to built the first to built the first MASERMASER based based

on this principle.on this principle.

LALASESERR

Charles H. Townes (left), winner Charles H. Townes (left), winner of the 1964 Nobel Prize for of the 1964 Nobel Prize for

Physics, and James P. Gordon Physics, and James P. Gordon in 1955 with the first in 1955 with the first MASERMASER..

Stimulated Emission Stimulated Emission Spontaneous EmissionSpontaneous Emission

Electrons in higher energy levels Electrons in higher energy levels if it is bombarded by a photon, if it is bombarded by a photon, lower energy level lower energy level (ground (ground state)state) emits a photon. emits a photon.

LALASESERR

Stimulated Emission Stimulated Emission Spontaneous EmissionSpontaneous Emission

To produce stimulated emission To produce stimulated emission atoms should be in the higher atoms should be in the higher unstable energy levels by unstable energy levels by energizing laser chamber with a energizing laser chamber with a flash lamp.flash lamp.

This process is called This process is called “population “population inversion”inversion” which end in the which end in the production of 2 photons same production of 2 photons same wavelength but with different wavelength but with different random directionsrandom directions

LALASESERR

AmplificationAmplificationPhotons reflect forwards and backwards due to Photons reflect forwards and backwards due to mirrors. mirrors. one photonone photon strikes an energized atom to strikes an energized atom to release release two photonstwo photons and so on = amplification of and so on = amplification of stimulated emission. stimulated emission.

LLAASERSER

RadiationRadiation

Laser is different than Laser is different than X-ray, cosmic rays, or X-ray, cosmic rays, or gamma raysgamma rays = = ionizing radiationionizing radiation affect the affect the molecular structure = cancer, while the laser light molecular structure = cancer, while the laser light

isis aa non-ionizing radiationnon-ionizing radiation. .

LASELASERR

Laser componentsLaser components

Optical cavity or the resonating tube: Optical cavity or the resonating tube: where the amplification of stimulated emission where the amplification of stimulated emission

occurs.occurs.

Laser medium: Laser medium: This could be solid, liquid, or gas.This could be solid, liquid, or gas.

Energy source: Energy source: which pumps energy to the laser medium to produce which pumps energy to the laser medium to produce

the population inversion.the population inversion.

Wave-guide:Wave-guide:as fiber-optic cable.as fiber-optic cable.

LASER tissue interactionLASER tissue interaction

When the skin is exposed to LASER, it could be When the skin is exposed to LASER, it could be transmittedtransmitted, or , or scatteredscattered by the skin structures, or by the skin structures, or absorbedabsorbed by the by the chromophoreschromophores..

Chromophores asChromophores as oxyhemoglobin, melanin, tattoo oxyhemoglobin, melanin, tattoo ink or water.ink or water.

Grothus-Draper photobiology lawGrothus-Draper photobiology law

Light should be absorbed to have a tissue effect Light should be absorbed to have a tissue effect if there is no light absorption there will be no if there is no light absorption there will be no effect.effect.

Absorption is controlled by Absorption is controlled by wavelengthwavelength of laser of laser and the and the chromophore.chromophore.

Theory of selective photothermolysisTheory of selective photothermolysis

In 1983 Drs. In 1983 Drs. R.A. AndersonR.A. Anderson and and J. A. ParrishJ. A. Parrish proposed this theory where a chromophore can be proposed this theory where a chromophore can be selectively damaged with a light pulse of an selectively damaged with a light pulse of an appropriate appropriate wavelengthwavelength and and suitable pulse durationsuitable pulse duration shorter than the shorter than the thermal relaxation timethermal relaxation time of that of that chromophore.chromophore.

Thermal relaxation timeThermal relaxation time

It is time of an object to loose heat energy to the It is time of an object to loose heat energy to the surroundings through thermal diffusion surroundings through thermal diffusion ((The time to The time to

disperse the heat absorbed during a laser pulse.)disperse the heat absorbed during a laser pulse.)

Thermal relaxation timeThermal relaxation time

If a If a chromophorechromophore is exposed to a laser for a time is exposed to a laser for a time longerlonger than its thermal relaxation time it will result than its thermal relaxation time it will result in collateral in collateral thermal damagethermal damage and and increased risk of increased risk of

complications.complications.

Pulse duration Pulse duration It is the time the laser is in contact with the target It is the time the laser is in contact with the target cell (cell (ChromophoreChromophore). ).

Types of LasersTypes of LasersGasGas Argon , CO2, Excimer laser Argon , CO2, Excimer laser

DyeDye Pulsed dye laser Pulsed dye laser

Solid Solid Ruby, Nd YAG and Er YagRuby, Nd YAG and Er Yag

Semiconductor Semiconductor Diode laserDiode laser

Laser light can be delivered in Laser light can be delivered in pulsespulses, , continuouscontinuous wave, or wave, or pseudo-continuous pseudo-continuous wave forms.wave forms.

Laser Photo effectLaser Photo effect

Photo thermalPhoto thermal Photo AcousticPhoto Acoustic Photo chemicalPhoto chemical

Laser parametersLaser parameters

Energy fluence (Energy density)Energy fluence (Energy density) Joules/cmJoules/cm22

= energy delivered to a given unit area for each = energy delivered to a given unit area for each single pulse.single pulse.

Irradiance (Power density)Irradiance (Power density) (Watt/cm(Watt/cm22)) = rate of energy delivery = intensity of the energy = rate of energy delivery = intensity of the energy delivered.delivered.

Efficacy of laser depends upon:Efficacy of laser depends upon:

The target chromophoreThe target chromophore WavelengthWavelength Pulse durationPulse duration Energy density Energy density

Target chromophoresTarget chromophores

as Oxyhemoglobin, Melanin, tattoo ink or water.as Oxyhemoglobin, Melanin, tattoo ink or water.

The target chromophoreThe target chromophore WavelengthWavelength Pulse durationPulse duration Energy density Energy density

WavelengthWavelength

Why sunset isWhy sunset is Red ? Red ? Why stop car lights areWhy stop car lights are in red color ? in red color ?

air scatter blue light from the sun more than they scatter red light .

The target chromophoreThe target chromophore WavelengthWavelength Pulse durationPulse duration Energy density Energy density

Electromagnetic spectrumElectromagnetic spectrum

Longer wavelengthsLonger wavelengths penetrate deeper into the target, penetrate deeper into the target, longer wavelengths are used to treat deeper targets of skin. longer wavelengths are used to treat deeper targets of skin.

Shorter wavelengthsShorter wavelengths are used to treat more superficial are used to treat more superficial targets and avoid damaging deeper skin partstargets and avoid damaging deeper skin parts. .

WavelengthWavelength

Optical window of the skin Optical window of the skin

Short wavelengthShort wavelength will limit the penetration depth of will limit the penetration depth of the beam due to limitation by the strong scattering the beam due to limitation by the strong scattering

effect.effect.

Longer wavelengthLonger wavelength, the scattering effect of the light , the scattering effect of the light is minimal is minimal deeper penetration of the light deeper penetration of the light and it and it

allows treatment of a deep dermal lesion allows treatment of a deep dermal lesion “optical “optical window” window”

Pulse duration Pulse duration It is the time the laser is in contact with the target It is the time the laser is in contact with the target cell (cell (ChromophoreChromophore). ).

ShortShort exposure time exposure time minimal heating of the minimal heating of the target target no effectno effect..

LongLong exposure time exposure time transfer of the heat transfer of the heat produced by conduction to adjacent tissues produced by conduction to adjacent tissues complicationscomplications as scarring, atrophy, or pigmentation as scarring, atrophy, or pigmentation

The target chromophoreThe target chromophore WavelengthWavelength Pulse durationPulse duration Energy density Energy density

Energy density (Energy fluence) Energy density (Energy fluence)

As the energy increases the amount of the clinical As the energy increases the amount of the clinical effect / complications is also increased and vice effect / complications is also increased and vice

versa.versa.

The target chromophoreThe target chromophore WavelengthWavelength Pulse durationPulse duration Energy density Energy density

Anaesthesia with laser Anaesthesia with laser

Without anaesthesia “Rubber sting”Without anaesthesia “Rubber sting”

LocalLocal EMLA cream produce a significant reduction EMLA cream produce a significant reduction in laser-induced pain. in laser-induced pain.

Excessive Use of Topical Anesthetics Can BeExcessive Use of Topical Anesthetics Can Be Fatal Fatal (FDA warning Feb 2007)(FDA warning Feb 2007)

General General Cold air currentCold air current Chill gelChill gel DCDDCD

Laser hazard classification scheme Laser hazard classification scheme Class I:Class I: No hazard No hazard Class II:Class II: < 1mW Human aversion is normally < 1mW Human aversion is normally sufficient protection (as looking away).sufficient protection (as looking away).Class III A:Class III A: 1-5 mW Hazardous only if someone 1-5 mW Hazardous only if someone looks directly at the laser beam.looks directly at the laser beam.Class III B:Class III B: 5-500 mW Diffuse scattering beams are 5-500 mW Diffuse scattering beams are dangerous Generally is not a fire hazard.dangerous Generally is not a fire hazard.Class IV:Class IV: high power: Even diffuse scattering is high power: Even diffuse scattering is dangerous to the eyes.dangerous to the eyes.

Potential fire hazard.Potential fire hazard. Potential skin hazard.Potential skin hazard.

Laser hazards and safetyLaser hazards and safety

1. Eye hazards1. Eye hazards2. Inhalation hazards2. Inhalation hazards3. Electrical hazards 3. Electrical hazards

4.4. Dye safety Dye safety 5.5. Skin safetySkin safety6. Fire hazard6. Fire hazard

Does laser inactivate botulinum toxin? Does laser inactivate botulinum toxin?

Patients may be treated with several nonablative Patients may be treated with several nonablative lasers and IPL or RF devices immediately after lasers and IPL or RF devices immediately after botulinum toxin injection without loss of efficacy or botulinum toxin injection without loss of efficacy or other apparent adverseother apparent adverse effect. effect.

Dermatol Surg. 2005 Apr;31(4):399-404Dermatol Surg. 2005 Apr;31(4):399-404.

Does laser affect Fillers? Does laser affect Fillers?

??????????????????

How is laser performedHow is laser performed??

How is LASER performed?How is LASER performed?Before treatmentBefore treatment

Clean the skinClean the skin Topical anesthetic Topical anesthetic Soothing gelSoothing gel PROTECTIVE GOOGLES.PROTECTIVE GOOGLES.

During LASER treatmentDuring LASER treatment

Probe is perpendicular on Probe is perpendicular on skinskin

Gentle pressureGentle pressure All senses are alertAll senses are alert Stretch the skin. Stretch the skin. Vacuum for fumes – virus Vacuum for fumes – virus

filter.filter. Overlap 10-20 %Overlap 10-20 % Imaginary line.Imaginary line.

During LASER treatmentDuring LASER treatment

Imaginary line Imaginary line Overlap 10 – 20 %Overlap 10 – 20 %

After LASER treatmentAfter LASER treatment

Cold or ice packs.Cold or ice packs.Local steroid + antibiotic.Local steroid + antibiotic.Topical non-steroid soothing cream.Topical non-steroid soothing cream.Avoid direct sun or heat exposure.Avoid direct sun or heat exposure.Physical and chemical sun screen.Physical and chemical sun screen.

Side effects.Side effects.

Side effects.Side effects.Burn Burn Post inflammatory hyper – hypo Post inflammatory hyper – hypo

pigmentation.pigmentation.Scar formation.Scar formation.

Principles of laser photo-Principles of laser photo-rejuvenation and scar treatment.rejuvenation and scar treatment.

What is Photo rejuvenation ?What is Photo rejuvenation ?

This approach is based on the concept that gentle This approach is based on the concept that gentle application of a variety of wavelengths in the visible and application of a variety of wavelengths in the visible and infrared spectra stimulates new collagen and perhaps infrared spectra stimulates new collagen and perhaps produces new elastic fiber that rejuvenates photoaged produces new elastic fiber that rejuvenates photoaged skin. skin.

Laser treatment for hypertrophic Laser treatment for hypertrophic scars, keloids, and striaescars, keloids, and striae

CW lasers CW lasers COCO22 , Er YAG no advantage over scalpel , Er YAG no advantage over scalpel excision. excision.

high rates of recurrence and other side effects including high rates of recurrence and other side effects including pain, atrophy, and dyspigmentation pain, atrophy, and dyspigmentation

Flash Lamp Pulsed Dye LaserFlash Lamp Pulsed Dye Laser Significant improvement in scar surface texture, Significant improvement in scar surface texture,

erythema, height, and flexibility.erythema, height, and flexibility.

Before After

After

Before

Before After

Longer wavelengthsLonger wavelengths penetrate deeper into the target, penetrate deeper into the target, longer wavelengths are used to treat deeper targets of skin. longer wavelengths are used to treat deeper targets of skin.

Shorter wavelengthsShorter wavelengths are used to treat more superficial are used to treat more superficial targets and avoid damaging deeper skin partstargets and avoid damaging deeper skin parts. .

WavelengthWavelength

Ablative laser systemsAblative laser systems(working (working hardhard or working smart) or working smart)

COCO22 laser laser emits a continuous-wave 10,600 nmemits a continuous-wave 10,600 nm

Er:YAG short-pulsed 2940-nmEr:YAG short-pulsed 2940-nm

Complications are numerous Complications are numerous Postoperative erythema, edema Postoperative erythema, edema Bacterial and viral infectionBacterial and viral infection Pigmentary alterationPigmentary alteration EctropionEctropion Hypertrophic scar formationHypertrophic scar formation

Non-ablative laser systemsNon-ablative laser systems (working (working smartsmart or working hard or working hard Titan-CTitan-C))

Nonablative laser resurfacing induces collagen Nonablative laser resurfacing induces collagen remodeling by creation of a dermal wound without remodeling by creation of a dermal wound without disruption of the epidermis.disruption of the epidermis.

585 - and 595-nm PDL 585 - and 595-nm PDL 1064 nm Nd:YAG.1064 nm Nd:YAG. 1320-nm Nd:YAG.1320-nm Nd:YAG. 1450-nm diode, and 1540-nm. 1450-nm diode, and 1540-nm. Er:glass lasers. Er:glass lasers. QS 1064-nm Nd:YAG laser.QS 1064-nm Nd:YAG laser. IPL. IPL.

Side effects: Side effects: mild and limited to transient edema, mild and limited to transient edema, erythema, and post-inflammatory hyperpigmentation.erythema, and post-inflammatory hyperpigmentation.

Non-ablative laser systemsNon-ablative laser systems Radio Frequency Radio Frequency ((RFRF))

RF treatment was very satisfactory for skin tighteningRF treatment was very satisfactory for skin tighteningLasers Surg Med. 2005.Lasers Surg Med. 2005.

The technique was found to produce gradual tightening in most The technique was found to produce gradual tightening in most patients, and there were no adverse effects patients, and there were no adverse effects

J CosmetJ Cosmet Laser Ther. 2005Laser Ther. 2005

Nonsurgical tightening of skin laxity: a new radiofrequency approach.Nonsurgical tightening of skin laxity: a new radiofrequency approach.J Drugs Dermatol. 2007 Apr;6(4):381-6. J Drugs Dermatol. 2007 Apr;6(4):381-6.

RF affects the deeper dermis and subcutaneous RF affects the deeper dermis and subcutaneous layers, causing tightening in texture or fine wrinkling. layers, causing tightening in texture or fine wrinkling.

Non-ablative laser systemsNon-ablative laser systems ((Fractional laserFractional laser))

Fractional laser 1,550nm Erbium glass fiber laser ------- Fractional laser 1,550nm Erbium glass fiber laser ------- microthermal zones microthermal zones (MTZs)(MTZs) of tissue coagulation of tissue coagulation ------- collagen remodeling and new collagen ------- collagen remodeling and new collagen formation.formation.

Pain.Pain. Cooling.Cooling.

• Fractional Laser treatment for pigmentation and texture improvement.Skin Therapy Lett. 2006 Nov;11(9):7-11.

• Fractional photothermolysis: treatment of facial and nonfacial cutaneous photodamage with a 1,550-nm erbium-doped fiber laser.Dermatol Surg. 2007 Jan;33(1):23-8.

• Fractional photothermolysis : A new option for treating melasma?

•Hautarzt. 2008 Feb;59(2):92-100.

Fractional LaserFractional Laser

Non-ablative laser systemsNon-ablative laser systems ((Fractional laserFractional laser))

Non-ablative laser systemsNon-ablative laser systems ((Fractional laserFractional laser))

improve skin texture and discoloration with a minimal amount of downtime. Skin remains intact allowing for a quick recovery.

The The FRACTIONALFRACTIONAL CO2 CO2 laser delivers microscopic holes 0.3mm laser delivers microscopic holes 0.3mm columns pixel like fashion of 10600nm, penetrating columns pixel like fashion of 10600nm, penetrating 20%20% of skin of skin

surface area right next to each other. The other surface area right next to each other. The other 80%80% of non-ablated of non-ablated skin surface areas facilitate faster healing.skin surface areas facilitate faster healing.

Before After

Before After

Before After

Before After

Advantage of Fractional Advantage of Fractional LaserLaser

Relatively short downtime, typically 4-6 daysRelatively short downtime, typically 4-6 days

Minimal discomfort as only topical anesthetics neededMinimal discomfort as only topical anesthetics needed

Safe and effective for virtually all skin surface areas Safe and effective for virtually all skin surface areas including face, neck, chest, back, arms and handsincluding face, neck, chest, back, arms and hands

Cosmetic appearance continues to improve with Cosmetic appearance continues to improve with stimulation of collagen production up to 6 months after stimulation of collagen production up to 6 months after procedureprocedure

Thank youThank you

الرحمن الله الرحمن بسم الله بسم الرحيمالرحيم

Intense Pulsed Light Intense Pulsed Light (IPL)(IPL)

Is it the future ?Is it the future ?

YYasser asser A.A. HHamed amed M.DM.D

Al-Azhar university Cairo – Egypt.Al-Azhar university Cairo – Egypt.Research Associate Minneapolis Minnesota USAResearch Associate Minneapolis Minnesota USA

lasercairo@yahoo.comlasercairo@yahoo.com

The intense pulsed light (IPL) source The intense pulsed light (IPL) source is high-intensity is high-intensity XenonXenon light lamp. light lamp.

IPL is unlike laser systems emit IPL is unlike laser systems emit polychromatic, noncoherent light polychromatic, noncoherent light within the 400 to 1900 nm portion of within the 400 to 1900 nm portion of the the electromagnetic spectrumelectromagnetic spectrum. .

Intense Pulsed LightIntense Pulsed Light

Electromagnetic spectrumElectromagnetic spectrumLight follows the basic properties of and Light follows the basic properties of and electromagnetic electromagnetic radiation.radiation. Light is composed of Light is composed of “Photons”“Photons” propagating in propagating in waves.waves.

Light parametersLight parameters

Each electromagnetic wave have a Each electromagnetic wave have a “Wavelength”“Wavelength” which is the which is the distance between two peaks measured in distance between two peaks measured in “nm”“nm”, “, “Amplitude”Amplitude” is the height of one peak and is the height of one peak and “Frequency”“Frequency” which is the which is the number of cycles per second number of cycles per second “hertz”“hertz”

Light tissue interactionLight tissue interaction

When the skin is exposed to light, it could be When the skin is exposed to light, it could be transmittedtransmitted, or , or scatteredscattered by the skin structures, or by the skin structures, or absorbedabsorbed by the by the chromophoreschromophores..

Chromophores asChromophores as oxyhemoglobin, melanin, tattoo oxyhemoglobin, melanin, tattoo ink or water.ink or water.

Grothus-Draper photobiology lawGrothus-Draper photobiology law

Light should be absorbed to have a tissue effect Light should be absorbed to have a tissue effect if there is no light absorption there will be no if there is no light absorption there will be no effect.effect.

Absorption is controlled by Absorption is controlled by wavelengthwavelength of laser of laser and the and the chromophore.chromophore.

Light parametersLight parameters

Energy fluence (Energy density)Energy fluence (Energy density) Joules/cmJoules/cm22

is the amount of energy delivered to a given unit is the amount of energy delivered to a given unit area of tissue for each single pulse.area of tissue for each single pulse.

Irradiance (Power density)Irradiance (Power density) (Watt/cm(Watt/cm22)) is the rate of energy delivery to an object, it is the rate of energy delivery to an object, it describes the intensity of the energy delivered.describes the intensity of the energy delivered.

Theory of selective photothermolysisTheory of selective photothermolysis

In 1983 Drs. In 1983 Drs. R.A. AndersonR.A. Anderson and and J. A. ParrishJ. A. Parrish proposed the theory of selective photothermolysis proposed the theory of selective photothermolysis which states that a chromophore can be selectively which states that a chromophore can be selectively damaged with a light pulse of an appropriate damaged with a light pulse of an appropriate wavelengthwavelength and and suitable pulse durationsuitable pulse duration shorter shorter than the than the thermal relaxation timethermal relaxation time of that of that chromophore.chromophore.

Thermal relaxation timeThermal relaxation time

It is time of an object to loose heat energy to the It is time of an object to loose heat energy to the surroundings through thermal diffusion. surroundings through thermal diffusion.

((The time to disperse the heat absorbed after light The time to disperse the heat absorbed after light exposure) exposure)

If a If a chromophorechromophore is exposed to a Pulse duration of is exposed to a Pulse duration of laser or light time laser or light time longerlonger than its thermal relaxation than its thermal relaxation

time it will result in collateral time it will result in collateral thermal damagethermal damage and and increased risk of complications.increased risk of complications.

Pulse duration Pulse duration It is the time the light is in contact with the target It is the time the light is in contact with the target cell (cell (ChromophoreChromophore). ).

Efficacy of light depends upon:Efficacy of light depends upon:

The target chromophoreThe target chromophore WavelengthWavelength Pulse durationPulse duration Energy density Energy density

Target chromophoresTarget chromophores

as Oxyhemoglobin, Melanin, tattoo ink or water.as Oxyhemoglobin, Melanin, tattoo ink or water.

The target chromophoreThe target chromophore WavelengthWavelength Pulse durationPulse duration Energy density Energy density

WavelengthWavelength

Why sunset isWhy sunset is Red ? Red ? Why stop car lights areWhy stop car lights are in red color ? in red color ?

air scatter blue light from the sun more than they scatter red light .

The target chromophoreThe target chromophore WavelengthWavelength Pulse durationPulse duration Energy density Energy density

Longer wavelengthsLonger wavelengths penetrate deeper into the target, penetrate deeper into the target, longer wavelengths are used to treat deeper targets of skin. longer wavelengths are used to treat deeper targets of skin.

Shorter wavelengthsShorter wavelengths are used to treat more superficial are used to treat more superficial targets and avoid damaging deeper skin partstargets and avoid damaging deeper skin parts. .

WavelengthWavelength

Optical window of the skin Optical window of the skin

Short wavelengthShort wavelength will limit the penetration depth of will limit the penetration depth of the beam due to limitation by the strong scattering the beam due to limitation by the strong scattering

effect.effect.

Longer wavelengthLonger wavelength, the scattering effect of the light , the scattering effect of the light is minimal is minimal deeper penetration of the light deeper penetration of the light and it and it

allows treatment of a deep dermal lesion allows treatment of a deep dermal lesion “optical “optical window” window”

Pulse duration Pulse duration It is the time the laser is in contact with the target It is the time the laser is in contact with the target cell (cell (ChromophoreChromophore). ).

ShortShort exposure time exposure time minimal heating of the minimal heating of the target target no effectno effect..

LongLong exposure time exposure time transfer of the heat transfer of the heat produced by conduction to adjacent tissues produced by conduction to adjacent tissues complicationscomplications as scarring, atrophy, or pigmentation as scarring, atrophy, or pigmentation

The target chromophoreThe target chromophore WavelengthWavelength Pulse durationPulse duration Energy density Energy density

Energy density (Energy fluence) Energy density (Energy fluence)

As the energy increases the amount of the clinical As the energy increases the amount of the clinical effect / complications is also increased and vice effect / complications is also increased and vice

versa.versa.

The target chromophoreThe target chromophore WavelengthWavelength Pulse durationPulse duration Energy density Energy density

IPL systems work on the same principle as lasersIPL systems work on the same principle as lasersLight is absorbed by the chromophores in the skin. Light is absorbed by the chromophores in the skin.

Light energy Light energy heat energy heat energy thermal damagethermal damage to the to the specific target specific target chromophoreschromophores . .

How IPL worksHow IPL works??

Pulsed Light can deliver several Pulsed Light can deliver several wavelength at a time using wavelength at a time using "cut off""cut off" filters to selectively deliver the desired filters to selectively deliver the desired wavelengths to reach the specific wavelengths to reach the specific Chromophore (target) Chromophore (target)

How IPL worksHow IPL works??

IPL emits wavelengths of light from 400 to 1200 -1900 IPL emits wavelengths of light from 400 to 1200 -1900 nm.nm.

Cut off filtersCut off filters block light shorter than the wavelength of block light shorter than the wavelength of the cut off filter. the cut off filter. For example:For example: a 550 nm cut off filter blocks light from a 550 nm cut off filter blocks light from 550 nm, and only allows wavelengths from 551 to 1200 550 nm, and only allows wavelengths from 551 to 1200 nm.nm.

How IPL worksHow IPL works??

Cut off filtersCut off filters? ?

Xenon lamp 530 Cut off filter530 Cut off filter

400 – 1200 nm

531- 1200 nm

When can Intense Pulsed Light be When can Intense Pulsed Light be performedperformed ? ?

There is no definite age regarding There is no definite age regarding IPL therapy.IPL therapy.

Does Intense Pulsed Light hurtDoes Intense Pulsed Light hurt??

Sensation of warmth sting or as a rubber Sensation of warmth sting or as a rubber band snap - individual variation – site.band snap - individual variation – site.

EMLA cream.EMLA cream. Chill gel . Chill gel .

Anaesthesia with IPL treatment Anaesthesia with IPL treatment

LocalLocal EMLA cream produce a significant reduction EMLA cream produce a significant reduction to pain. to pain.

Excessive Use of Topical Anesthetics Can BeExcessive Use of Topical Anesthetics Can Be Fatal Fatal (FDA warning Feb 2007)(FDA warning Feb 2007)

Cold air currentCold air current Chill gelChill gel

Simpler to operate than laser Simpler to operate than laser It interacts to tissue similarly to laserIt interacts to tissue similarly to laser It has a bigger spot size than any laser, larger It has a bigger spot size than any laser, larger

areas could be treated very quicklyareas could be treated very quicklyCan treat a wider range of skin type, hair type. Can treat a wider range of skin type, hair type. Not as powerful as most lasers and may Not as powerful as most lasers and may

possibly need more treatments to obtain same possibly need more treatments to obtain same results. results.

IPL IPL VersusVersus LASER LASER

IPL IPL VersusVersus LASER LASER

How is IPL performedHow is IPL performed??

Before IPL treatmentBefore IPL treatment

History History ExaminationExaminationWritten consent Written consent Photo documentationPhoto documentationDetails of therapyDetails of therapyTest patch/spot Test patch/spot FilingFiling

How is Intense Pulsed Light performedHow is Intense Pulsed Light performed?? Clean the skinClean the skin Topical anesthetic Topical anesthetic Soothing gelSoothing gel PROTECTIVE GOOGLES.PROTECTIVE GOOGLES.

During IPL treatmentDuring IPL treatment

Probe is Probe is perpendicular on skinperpendicular on skin

Gentle pressureGentle pressure Overlap 5-10 %Overlap 5-10 % All senses are alertAll senses are alert Imaginary line – filter Imaginary line – filter

imprint on the gel.imprint on the gel.

During IPL treatmentDuring IPL treatment

Imaginary line – filter Imaginary line – filter imprint on the gel.imprint on the gel.

Hazard classification scheme Hazard classification scheme Class I:Class I: No hazard No hazard Class II:Class II: < 1mW Human aversion is normally < 1mW Human aversion is normally sufficient protection (as looking away).sufficient protection (as looking away).Class III A:Class III A: 1-5 mW Hazardous only if someone 1-5 mW Hazardous only if someone looks directly at the laser beam.looks directly at the laser beam.Class III B:Class III B: 5-500 mW Diffuse scattering beams are 5-500 mW Diffuse scattering beams are dangerous Generally is not a fire hazard.dangerous Generally is not a fire hazard.Class IV:Class IV: high power: Even diffuse scattering is high power: Even diffuse scattering is dangerous to the eyes.dangerous to the eyes.

Potential fire hazard.Potential fire hazard. Potential skin hazard.Potential skin hazard.

IPL hazards and safetyIPL hazards and safety

1. Eye hazards1. Eye hazards2. Inhalation hazards2. Inhalation hazards3. Electrical hazards 3. Electrical hazards

4.4. Skin safety Skin safety5. Fire hazard5. Fire hazard

Precautions to be considered with Precautions to be considered with laser and IPL ttt.laser and IPL ttt.

Dark skin typeDark skin type Cooling ……. Epidermal protection.Cooling ……. Epidermal protection. Wavelength (appropriate cut off filter).Wavelength (appropriate cut off filter). Pulse duration.Pulse duration. Energy density. Energy density. Sun light …….. Heat exposure after ttt…. Sun Sun light …….. Heat exposure after ttt…. Sun block ….. Local steroid & antibioticblock ….. Local steroid & antibiotic

WHAT CAN IPL TREAT ? WHAT CAN IPL TREAT ? Hair epilation - (except for white hair) Hair epilation - (except for white hair) Psudofolliculitis barbae Psudofolliculitis barbae Rosacea Facial Blood Vessels including PWS Rosacea Facial Blood Vessels including PWS

& Hemangiomas & Hemangiomas Pyogenic granulomaPyogenic granuloma Freckles - Sun Damage Freckles - Sun Damage

- Wrinkles - Wrinkles (Non Ablative Resurfacing)(Non Ablative Resurfacing) Scars – atrophic – hypertrophic- keloidScars – atrophic – hypertrophic- keloid CelluliteCellulite Acne Acne Acne and PDTAcne and PDT Tattoos Tattoos

Non-ablative ResurfacingNon-ablative Resurfacing

Nonablative resurfacing induces collagen remodeling by Nonablative resurfacing induces collagen remodeling by creation of a dermal wound without disruption of the creation of a dermal wound without disruption of the epidermis.epidermis.

585- and 595-nm PDL 585- and 595-nm PDL 1064-nm Nd:YAG, 1064-nm Nd:YAG, 1320-nm Nd:YAG, 1320-nm Nd:YAG, 1450-nm diode, and 1540-nm 1450-nm diode, and 1540-nm Er:glass lasers. Er:glass lasers. QS 1064-nm Nd:YAG laserQS 1064-nm Nd:YAG laser IPL IPL Side effects mild and limited to transient edema, erythema, Side effects mild and limited to transient edema, erythema,

and postinflammatory hyperpigmentation.and postinflammatory hyperpigmentation.

Side effects.Side effects.

Side effects.Side effects.Dark Skin typeDark Skin typeOver dose Over dose Pulse durationPulse durationCooling of the skinCooling of the skinSolar or heat exposureSolar or heat exposureTest patch/spotTest patch/spotPatient selectionPatient selectionDrugs Drugs

Thank youThank you

الرحمن الله الرحمن بسم الله بسم الرحيمالرحيم

Yasser A. Hamed M.DYasser A. Hamed M.DAl-Azhar universityAl-Azhar university

Research Associate Minneapolis University Minnesota USAResearch Associate Minneapolis University Minnesota USA lasercairo@yahoo.comlasercairo@yahoo.com

Other and new LASEROther and new LASERindicationsindications

Laser and Photodynamic therapy Laser and Photodynamic therapy (PDT) ? (PDT) ?

Laser and Photodynamic therapy Laser and Photodynamic therapy (PDT)? (PDT)?

PDT uses laser, or other light sources, combined PDT uses laser, or other light sources, combined with a light-sensitive drug (sometimes called a with a light-sensitive drug (sometimes called a photosensitising agent). photosensitising agent).

A photosensitising agent is a drug that makes cells A photosensitising agent is a drug that makes cells more sensitive to light.more sensitive to light.

Laser and Photodynamic therapy Laser and Photodynamic therapy (PDT)? (PDT)?

levulan levulan kerastick (Aminolevulinic kerastick (Aminolevulinic acid hydrochloride) acid hydrochloride) 

Laser and PDT? Laser and PDT? Nonablative Nonablative skin resurfacingskin resurfacing: the role of PDT.: the role of PDT.

J Drugs Dermatol. 2006J Drugs Dermatol. 2006 PDT in the treatment of PDT in the treatment of photodamagedphotodamaged facial skin. facial skin.

skin.Lasers Surg Med. 2007skin.Lasers Surg Med. 2007 intense pulsed light with PDT for the treatment of facial intense pulsed light with PDT for the treatment of facial acneacne

Lasers Surg Med. 2007Lasers Surg Med. 2007 PDT treatment of PDT treatment of Bowen'sBowen's disease. disease.

Br J Dermatol. 2005Br J Dermatol. 2005 PDT Actinic keratoses, basal cell carcinoma, and PDT Actinic keratoses, basal cell carcinoma, and SCCSCC uncommon treatments. uncommon treatments.

Clin Dermatol. 2005Clin Dermatol. 2005 Topical 5-aminolevulinic acid therapy of superficial Topical 5-aminolevulinic acid therapy of superficial BCCBCC..

Acta Derm Venereol. 2006Acta Derm Venereol. 2006 PDT of PDT of nodular basal cell carcinomanodular basal cell carcinoma..

J Environ Pathol Toxicol Oncol. 2006J Environ Pathol Toxicol Oncol. 2006 PDT to treat AIDS-related PDT to treat AIDS-related Kaposi'sKaposi's sarcoma. sarcoma.

Photomed Laser Surg. 2006Photomed Laser Surg. 2006.. PDT with systemic photosensitizer for PDT with systemic photosensitizer for nonmelanomanonmelanoma skin cancers . skin cancers .

Dermatol Surg. 2007Dermatol Surg. 2007

TSCTSC

PBCC before and after

Laser phototherapyLaser phototherapy

UV phototherapy UV phototherapy PUVAPUVA KUVAKUVA Narrow band UVB 311 nmNarrow band UVB 311 nm Recently 308-nm xenon chloride excimer laserRecently 308-nm xenon chloride excimer laser

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