The Use of IR Lasers in Wound Healing

The Use of IR Lasers In Wound Healing

Jim Ohneck, FASLMS

Overview

Brief Review of Laser Technology

Laser Therapy Biology

Scientific Work

Clinical Work

LASER

An acronym for:

Light

Amplification by

Stimulated

Emission of

Radiation

Properties of Laser Light

Laser Classifications

Class IIIa = lasers 1 to 5mw of power (laser pointers)

Class IIIb = lasers 6 to 500mw in power (typical cold laser you read about)

Class IV = lasers above 500mw of power

Surgical versus Therapeutic Lasers

Surgical Laser Beam- Infrared energy collimated to a fine beam causes tissue destruction

Therapeutic Laser Beam- dispersal of same energy causes tissue stimulation

Laser Energy has the capability to penetrate into tissue to varying depths depending on its

corresponding wavelength, power and energy

concentration

Lasers in Medicine

Surgical Lasers: are used to cut, coagulate and evaporate tissues. This type of laser replaces the scalpel of the surgeon.

Lasers in Medicine

Therapeutic Lasers: are used for the stimulation of cell function.

The biological effect is photochemical not thermal, as is the case with surgical lasers.

How Light Penetrates Tissue

As light energy hits the surface of the skin and subsequent deeper layers, some of it is scattered and some of it is absorbed

At each tissue interface less energy is available to pass further through to the next layer because of the effects of absorption, reflectance and transmission

Laser Tissue Interactions

Laser Tissue Interaction

The longer the wavelength the deeper

the penetration in the IR-A spectrum

Absorption Curves

Low melanin, low water, low hemoglobin

Depth Penetration Factors

Patient

Skin pigmentation, hair

Thickness of each tissue layer

Vascular content of treatment area

Cleanliness of treatment area

Heat results in increased vasodialation

Heat caused by improper choice of wavelength

Hot spots within the fiber

Heat is a natural by product of absorption

Depth Penetration Factors

Instrumentation

Total power

Spot size

Dosage

Power density

Wavelength

Method of delivery

Clinical Variables

ClinicalFrequency of treatmentsDuration of treatmentsTotal number of treatmentsTime between treatmentsMethod of applicationCondition being treatedArea of the woundWound dressings/topical agents

Importance of Power Density

Approximately 65% of the energy delivered is lost in the epidermis

If you don’t start with enough energy there will not be enough to stimulate cell healing

If you do not have sustained power density over a long enough period of time treatments may be ineffective

Too much power density can also be detrimental

Laser Therapy Paradigm

Think of therapeutic lasers as you would a biochemical paradigm, the difference being that light initiates the chain reaction of events

Cellular Effects of Laser Energy

Chromophores are components of molecules which absorb light.

The stimulation of chromophores on mitochondrial membranes incites the production of cellular energy (ATP).

Cellular Effects of Laser Energy

Increased Growth factor response within cells and tissue as a result of increased ATP and protein synthesis

Accelerated cell reproduction and growth leading to faster repair of damaged tissues.

Increased metabolic activity- via increase in enzyme outputs, oxygen and nutrient availability.

Why IR Laser for Wounds

Depth penetration and absorption characteristics

Technology well developed and used in other medical disciplines, such as pain management

Promising scientific evidence

EFFECTS OF INFRARED LASER EXPOSURE IN A CELLULAR MODEL OF WOUND

HEALING

Mark Skopin, James Ohneck and Scott Molitor

Recent Research

Local Work Using IR Laser

EFFECTS OF INFRARED LASER EXPOSURE IN A CELLULAR MODEL OF WOUND HEALING

Moderate doses of IR light improves wound healing in vitro

Beneficial effects reduced or negated by excessive exposure

Demonstrates need for supervised treatment

Requires use of well-developed protocol

Exposure doses require knowledge of wound depth, skin pigmentation and absorption characteristics at each tissue layer

In vitro method useful for testing novel light sources or treatment paradigms

Automated image processing routines allow for accurate quantification of results

Power density was the most important identified parameter

Scott Molitor, Mark Skopin, James Ohneck

Scientific & Clinical Validation

New York Institute appearing in Photomedicine and Laser Surgery, Volume 22, Number 3 2004 authored by Chukuka S. Enwemeka, Ph.D., FACSM

“The Efficacy of Laser Therapy in Wound Repair: AMeta-Analysis of the Literature”

Scientific & Clinical Validation

New York Institute ArticleMeta analysisEvaluated stringent inclusion criteria

Type of LASER and precise wavelengthLaser clearly identified as independent variableAt least one index of wound healing identified as dependent variableParameters on laser power and time were clearly statedCondition treated clearly stated

Scientific & Clinical Validation

New York Institute Article

Conclusion was that laser therapy was effective for treating wounds

That outcomes vary with treatment parameters

Energy density was the only parameter with predictable dose dependent effects

Local Work Using IR LaserPain And Wound Healing After Acute Traumatic Injury

Slight decrease in pain as measured by FACES pain scale at 6 weeks in LASER group compared with control group

Slight improvement on wound healing rate as measured on serial pictures

Acute traumatic injury

( 1 week postop)

Acute traumatic injury

( 4 weeks postop)

After 7 Laser treatments

Acute traumatic injury

( 12 weeks postop)

Conclusions

Considerable Data is available to support the use of lasers therapeutically for wound healing

Basic scientific work has begun, some locally

IR Lasers offer demonstrated wound healing opportunities along with the advantage of stable core technology, increased depth penetration and larger treatment beam diameters