Laser Treatment Safety and Function Quiz

Laser/Light Science & Safety

• Laser is an acronym for Light Amplification by Stimulated Emission of Radiation
• Laser light in an apparatus is either invisible or visible
• Amplification increases energy to a certain intensity
• Stimulated Emission is the molecular process of amplifying light within a laser
• Radiation is a broader term used to describe emission throughout the electromagnetic spectrum
• Light is composed of packets of energy called photons
• All light on Earth (except laser light) is produced by spontaneous emission of photons
• In 1914, Albert Einstein proposed the theory of Stimulated Emission of Radiation
• Stimulated emission generates high-intensity energy through an atomic process that releases identical, unidirectional photons

Learning Objectives

• Laser Science Overview
• Understanding Selective Photothermolysis
• Lasers vs. IPL
• Laser/Light Tissue Interactions
• Laser and IPL Safety Guidelines

What is a Laser?

• Laser is an acronym for Light Amplification by Stimulated Emission of Radiation
• Describes what laser light does in the apparatus before release
• Laser light can be invisible or visible
• Amplification increases energy to a specific intensity
• Stimulated emission is the molecular process of light amplification
• Radiation is a broader term for emissions throughout the electromagnetic spectrum

The Product of a Laser is LIGHT

• Light is made of energy packets called photons
• All earthly light except for laser light results from spontaneous emission of photons
• In 1914, Albert Einstein proposed the theory of Stimulated Emission of Radiation
• Stimulated emission generates extremely high-intensity energy through atomic processes, releasing identical, unidirectional photons

Lasers

• The product of a laser is light
• Laser gain medium, excitation energy, rear mirror, front mirror/output coupler are components of a laser
• Input energy, power supply, laser medium, cooling supply, delivery system are components of a laser

All Lasers have a Medium

• The medium of a laser is named after it and is the energy source that creates the wavelength
• Solid lasers (Alexandrite 755nm, Diode 800-950nm, 1064nm Nd:YAG, 2940nm Er:YAG) are solid substances
• Liquid lasers (Pulsed Dye Laser 585nm-595nm)
• Gas lasers (532nm KTP, 10,600nm CO2)

Understanding Selective Photothermolysis

• Selective photothermolysis (Anderson & Parrish, 1983) selectively absorbs light of a specific wavelength by the target chromophore
• Exposure (pulsewidth) is limited to less than the thermal relaxation time of the chromophore
• Sufficient fluence (energy) reaches the chromophore to cause the desired effect
• Selective: The procedure "selects" an abnormal area to treat, contrasting with the surrounding tissue.
• Photo: The laser emits light
• Thermo: The light generates heat.
• Lysis: Refers to the destruction of tissue.
• Selective photothermolysis uses light to heat and destroy tissue in a specific area of the body.

Electromagnetic Spectrum – Wavelengths

• Displays wavelengths for aesthetic lasers measured in nanometers
• Shows visible and invisible laser wavelengths
• Visible light wavelengths are those visible to the naked eye
• Shorter visible wavelengths are more hazardous to darker skin and produce more heat on the skin's surface

EMS: Electromagnetic Spectrum

• The diagram displays various wavelengths for aesthetic lasers, measured in nanometers.
• Nanometers are billionths of a meter
• The electromagnetic spectrum contains areas of laser wavelengths: visible and invisible
• Visible wavelengths are what the naked eye can see.
• Shorter visible wavelengths are more hazardous to darker skin and create more heat at the skin surface.
• The shorter the wavelength, the more dangerous it is for darker skin, and the more heat it produces on the skin's surface

Frequency & Wavelength

• Shows relationships between frequency, wavelength, and amplitude
• High frequency correlates with short wavelengths
• Low frequency correlates with long wavelengths

Wavelength Depth of Penetration with Comparable Spot Sizes Used

• Display wavelengths of various lasers, their depths of penetration in the skin, and comparable spot sizes
• Shows how spot size impacts laser penetration depth

Non-Ionizing VS Ionizing

• Non-ionizing radiation does not use ionizing radiation
• Ionizing radiation is less than 400nm, penetrates and enters DNA, RNA, and can cause cancer
• The medical aesthetic industry uses non-ionizing radiation (400nm to 10,600nm)

Understanding Pulsewidth

• Pulsewidth, Pulse Duration, and time in milliseconds are the same measurements
• Pulsewidth represents the length of time the laser or light is emitted

Characteristics of a Short Pulsewidth

• Delivers fluence/energy quickly
• Energy is absorbed more superficially
• More intense tissue reaction
• Less cooling time; used for smaller target treatment

Characteristics of a Long Pulsewidth

• Delivers fluence/energy over a longer period
• Energy penetrates deeper
• Allows for thermal relaxation time; used safely for skin types IV, V, VI; for larger deeper targets
• Requires more time to reach desired temperature

Short PW vs. Long PW - Simplified

• Short pulse (aggressive) compared to long pulse

Pulse Duration (Pulsewidth)

• Shows the relationship between pulse duration (millisecond and nanosecond to picosecond) and types of laser interactions
• Photothermal methods involve selective photothermolysis, thermal confinement, optimum heating, minimized collateral damage, laser parameters, wavelengths, and pulse duration less than relaxation time
• Photomechanical methods involve mechanical forces, target pressure, minimized collateral damage, laser parameters, wavelengths, and pulse duration consistent with acoustic propagation

Understanding Fluence

• Energy fluence is measured in joules (J) and determines the amount of laser energy delivered in a single pulse (measured in joules/cm²)
• Increases in fluence can be achieved by reducing the laser beam to a smaller spot size; however, this results in longer treatment times
• Effective treatment fluence decreases in smaller spot sizes

Understanding Fluence

• Heat and energy are measured as fluence or joules
• Fluence is adjusted based on the skin's clinical response to achieve desired results
• Joule represents the total energy emitted by a laser light
• Fluence is the energy over spot size (J/cm²)

Laser Output Terminology

• Power is measured in Watts
• Pulse duration is measured in seconds
• Energy is measured in joules
• Frequency is measured in Hertz
• Fluence is the amount of energy (J/cm²) applied to tissue per unit area

Lasers vs. Intense Pulsed Light

• Lasers produce a specific wavelength of light going in one direction, creating a single beam like a laser pointer
• IPL devices produce a wide range of wavelengths of light, producing a white flash, similar to a camera flash

Properties of a Laser

• Monochromatic, Coherent, Collimated

Properties of Pulsed Light

• Polychromatic, Incoherent/Divergent, Non-collimated/diffused

Lasers vs. Pulsed Light

• Displays a table contrasting properties of lasers and pulsed light - lasers - monochromatic, coherent, collimated - Pulsed light - polychromatic, incoherent/divergent, diffused

Cynosure Correlation to IPL Wavelengths

• Table showing Cynosure devices, IPL system types, purposes, wavelengths, and Fitzpatrick skin types

Cynosure Correlation to Laser Wavelengths

• Table showing Cynosure devices, laser system types, purposes, wavelengths, and Fitzpatrick skin types

Cynosure Correlation to Wavelengths

• Table showing Cynosure devices, laser types, purposes, wavelengths, and Fitzpatrick skin types

Lasers/Light Tissue Interactions

• When a laser or IPL is used on skin, reflection, absorption, transmission and scattering occur.
• Absorption is the most important factor, directly related to the target chromophore and the spot size of delivery

Understanding Spot Size

• Larger spot sizes are used for deeper penetration into larger targets
• Smaller spot sizes are used for shallower conditions and smaller targets

Large Spot Size = Better Penetration

• Illustrates how larger spot sizes permit deeper penetration

Target Chromophores

• Absorption coefficient graph showing how different chromophores absorb various wavelengths
• Shows how different chromophores absorb various wavelengths

Target Chromophores

• Wavelengths absorb blood; melanin triggers rapid cell proliferation; melanin in tattoos is targeted; melanin in hair is targeted for hair reduction; wavelengths targeting water heat tissues, stimulating collagen and elastin growth, reducing scars and wrinkles

Unique Clinical Targets (Chromophore)

• Table showing clinical applications, target chromophores, and corresponding effects.

Laser/IPL Safety Guidelines

• Discusses the safety regulations for laser and IPL use

Regulatory Agencies

• Lists ANSI standards (Z136.1-2014, Z136.3-2011, Z136.8-2012) and FDA/CDRH, and OSHA citations of ANSI standards for laser safety

Laser Systems at Cynosure

• Lists various laser systems used at Cynosure, along with their respective wavelengths

IPL Systems

• IPL is not laser light; it uses multiple wavelengths; 500-1200nm range; safety glasses are required

Eye Hazards

• Brightness and directionality contribute to risks
• Beam concentration on the retina is significantly higher (up to 100 times) than normal light.
• Wavelength of light determines the eye part at risk
• Beam may be invisible.
• Aversion response (blinking) does not protect from invisible lasers.
• Class 4 lasers can damage the eye in less time than blinking
• Cornea, lens, and retina are susceptible eye structures

Laser Eye Safety Precautions

• Always knock before entering a laser area, and control access
• Output from Nd lasers and other IR lasers is invisible to the human eye
• Treat laser beams like guns; point them toward the floor, never at people or windows

Avoiding Eye Injuries

• Never look directly into a handpiece
• Practice caution near the eyes
• Use caution near the eyes during procedures
• Keep equipment in standby mode, only turn on when ready to treat
• Never direct a beam upwards from horizontal (aim beam at the floor); treat laser like a gun
• Contain laser beam in designated areas; use suitable curtains, shields, a closed door, and proper warnings.
• Be aware of reflective surfaces and avoid beams/reflections

Root Causes of Eye/Skin Exposure Incidents

• Misaligned optics, lack of eye protection, insufficient beam control, use of improper beam direction

Everyone must have Eye Protection

• Required for all personnel in laser areas

CONTROL MEASURES

• Engineering controls: protective housing, interlocks, enclosed beam path, signage, remote interlock connector, and key control
• Administrative controls: standard operative procedures, training, signs and labels, areas defined by hazard
• Personal protective equipment (PPE): laser safety eyewear and protective clothing (when appropriate)

LASER WARNING SIGNS

• Sign indicates that lasers are in use and that safety eyewear is required to enter areas

Safety Summary

• During treatment, the practitioner must control the environment
• Everyone in the room should wear correct safety eyewear
• Use appropriate signage

Questions?

• Open-ended question for potential Q&A

Thank You!

• Closing statement