Introduction to Lasers

• Aesthetic Dermatology

  A branch of modern medicine that focuses on altering a patient's cosmetic appearance through the treatment of conditions
• Conditions treated in Aesthetic Dermatology

  • Scars
  • Skin Laxity
  • Wrinkles
  • Moles
  • Birthmarks
  • Hair reduction
  • Skin discoloration
  • Tattoo removal
• Lasers have been used in aesthetic medicine for decade with continued advancement in technology and new indications for treatment
• Lasers

  • A sub-division of Dermatology
  • An area of interest in medical practice
  • Boosts self confidence and revamp whole body image
• Ways to improve skin condition and attractiveness

  • Topical Creams
  • Medi Facials
  • Lasers
  • Injectables
  • Tablets : Supplements & Medication
  • Cosmetic surgeries
  • Lifestyle
• Myths about Lasers

  • Pain?
  • Skin becomes thin?
  • Downtime?
  • Not lasting? Not effective?
  • Harmful? Cause cancer?
  • Expensive?
• LASER

  Light Amplification by Stimulated Emission of Radiation
• Lasers are different from other lights because the light which the laser device emits has identical frequencies and wavelengths in it. As a result a narrow tight beam of light is produced
• The Ruby laser was the first laser to be made functional built by Theodore Maiman in 1960
• Lasers are a technology that we can use to solve patients' different type of skin problems
• Characteristics of Lasers

  • Monochromatic: Light from a laser contains only a single wavelength
  • Coherence: Light from a laser is coherent meaning the waves of light run parallel to each other
  • Directionality: The light from a laser is emit in a particular focused direction

  
• Laser components

  • Laser medium
  • Source of energy
  • High reflector
  • Output coupler
  • Laser beam
• Main laser components

  • Laser medium: Such as solid, liquid or gas
  • Source of energy: To introduce energy into a laser system to produce a population inversion
  • Optical Resonator: To enable the laser system to produce a highly focused, coherent and directional beam of light
• Laser physics: The Emission- absorption principle

  1. Absorption: An electron from lower level absorbs a photon of frequency hv and moves to an upper level

  2. Spontaneous emission: An electron in an upper level can decay spontaneously to the lower level and emit a single photon of frequency hv

  3. Stimulated emission: Energy released by electrons moving from upper level to lower level, followed by the collision with excited atom releasing 2 photons identical in wavelength, direction and phase
• Laser tissue Interaction

  • Reflection: The laser beam bounces off the surface with no penetration or interaction at all
  • Absorption: Specific molecules in the tissue known as chromophores absorb the photons
  • Transmission: The laser energy transmitted through superficial tissues to interact with deeper areas
  • Scattering: Once the laser energy enters the target tissue it will scatter in various directions
• Chromophore

  • Selective target in the skin that a laser wavelength is targeted too
  • Determined by the wavelength and generally one wavelength will only target one chromophore over others
  • If there are 2 competing chromophores at the same wavelength, the depth of penetration is based on the higher graph of absorption
• Major skin chromophores

  • Melanin
  • Haemoglobin
  • Water
• Melanin

  • Absorbed between wavelengths of 500 nm to 1200nm but the depth depends on the location of the pigmentation
  • Pigment can be deep in the dermis like hormonal melasma, or superficial in the epidermis like in sun damaged skin; or abit of both
  • Melanin is also found within hair follicles when is deep in the skin, therefore hair removal lasers need to go deep with a longer wavelength
• Haemoglobin

  • Found within blood vessels and gives the blood its red color
  • Lasers that target hemoglobin are used to treat capillaries, flushing, broken blood vessels, rosacea and red scars
• Water

  • Best absorbed by longer wavelength but sits in all levels in the skin
  • Water is the target of "ablative" lasers, that work to resurface the skin and treat conditions such as scarring, wrinkles and texture
• Basic Parameters of a Laser

  • Wavelength
  • Fluence
  • Spot Size
  • Pulse Duration
  • Quality Switched / Q-Switched
• Wavelength

  • The distance between two peaks measures in nanometres
  • Wavelengths must be consistent with the target tissue/colour
  • The shorter the wavelength, the more superficial the penetration and the higher the energy; the longer the wavelength, the deeper penetration and the lower the energy
• Laser Source and Wavelength Peaks

  • CO2: 10,600 nm
  • Argon: 488/514 nm
  • Potassium-titanyl-phosphate (KTP): 532 nm
  • Copper bromide: 578 nm (yellow), 511nm (green)
  • Pulsed dye laser (PDL): 585–595 nm
  • Ruby: 694 nm
  • Alexandrite: 755 nm
  • Neodymium (Nd):yttrium-aluminum-garnet (YAG): 1064 nm
  • Erbium:YAG: 2940 nm
• Fluence

  • A measure of energy delivered per unit area, commonly used unit is Joules per square centimeter (J/cm2)
  • Helps to avoid busting damage threshold, and also to ensure good process quality
  • If too much fluence is used, it can cause more damage to surrounding tissue but if too little fluence is used, the laser may not penetrate deep enough into the skin to be effective
  • To penetrate deeper layers of the epidermis and dermis, we increase the fluence in subsequent sessions of laser treatment to achieve optimal results in a gradual and safe way
• Spot Size

  The size of the laser beam, smaller spot size means greater heat energy is transferred to the target
• Pulse Duration

  • The delivery time or exposure time of the selected energy delivered to the target tissue
  • Different target volumes require different energy exposure times
  • Thermal Relaxation Time (TRT) is the time required by an object to cool down to 50% of the initial temperature achieved
  • To achieve a desired heating effect in the tissue target, the energy must be contained in the target without "losing" the heat into the surrounding tissue, so the delivery time must be faster than the target TRT or cooling time
• Quality Switch / Q-Switch

  • A technique by which a laser can be made to produce a pulsed output beam
  • Allows the production of light pulses with extremely high (gigawatt) peak power, much higher than would be produced by the same laser if it were operating in a continuous wave (constant output) mode
  • Q-switching leads to much lower pulse repetition rates, much higher pulse energies, and much longer pulse durations
• Types of Lasers in Aesthetic Medicine

  • Ablative
  • Non-Ablative
  • Fractional
  • Non-Fractional
• Ablative Lasers

  • Vaporize tissue layers by superheating water molecules contained in the skin cells, and as water turns into gas, the skin cells are then vaporized
  • Removing the targeted skin the resultant healing would produce smoother and rejuvenated skin
  • Down time for such lasers lasts 7 to 10 days
• Non-Ablative Lasers

  • Much gentler and leave the skin intact, generally have little to no down time
  • Work to heat the skin below, treat particular skin condition such as vessels, pigment and stimulate collagen production by using specific laser wavelengths to improve the appearance of the skin without injuring the skin itself
  • Various laser wavelength targets different chromophore (colour) on our skin and because each laser wavelength have specific affiliate towards a particular chromophore, careful laser selection is very important
• Fractional Lasers

  • Treat only portions of the treatment area
  • Produce small columns of thermal injury known as microthermal zones (MTZ) which can be either non-ablative dermal injuries only or both epidermal and dermal injuries with the ablative lasers
• Non-Fractional Lasers

  Treat the entire treatment area
• Treatable Skin Problems

  • Pigmentation
  • Acne
  • Scars
  • Lumps, Bumps, Warts & Cysts
  • Sensitive Skin
  • Vessels
  • Aging
  • Skin Tightening
• Laser Types for Skin Problems

  • Pigments specific lasers
  • Pigments, Vascular & Inflammatory
  • Skin resurfacing lasers
  • Hair removal lasers
• The Other Side of Lasers

  • Post-inflammatory hyperpigmentation (PIH) / hypopigmentation
  • Allergic Reactions
  • Burns
  • Infections
  • Bruises, Bleeding
  • Scarring
  • Anaesthetic Reactions
• To avoid complications, It's of the utmost importance to have Fundamental Knowledge & Skills
• The Other Side of Lasers

  • Know the common lasers
  • Know what lasers are available to you
  • Know how to maintain your Lasers
  • Know how to answer your customer questions about lasers