Laser Therapy: Applications

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Laser Eye Surgery

The structure of the eye is composed of a single, outwardly curved (convex) clear lens, the cornea, at the front and a lengthy 'fiber optic' cable, the optic nerve, extending from the back.
It is essentially an empty structure, except for the colored iris, a circular band of muscles that controls the size of the pupil, which allows variable amounts of light to pass to the back inside the surface of the eye. The amount of pigmentation of the iris determines its color. Blue eyes, for example, have very little amount of pigment, and black eyes have the most.
The pupil is the central transparent area, that is controlled by the ciliary muscles in the iris, that make the pupil smaller when the amount of light is excessive, and vice versa.

Light rays pass through the clear cornea, which due to its curved surface, is able to bend (refract) the light rays. These light rays are concentrated together and pass through the pupil. Then, they go through the normally clear lens which has two curved surfaces, the front and the back. Therefore, these light rays are bent (refracted) two more times on their trip to the back of the eye.

The light rays travel to the back surface of the eye through the vitreous, a clear jelly which fills the space between the back of the lens and the retina, the inside lining of the back surface of the eye which contains specialized cells which convert light energy into electrical impulses.
These cells are either called rods, specialized for black and white images, or cones, that mainly process color images. In dim light, we use our rods, which cannot work in bright light. To deal with bright or moderate light, we use our cones, that beside providing color vision, they also process some aspects of black and white vision and the ability to discern fine detail.

What is truly amazing about the eye is how part of these cells in the retina (photosensitive cells) actually are a six inch appendage of the cell, the axon, which joins with other axons to compose the optic nerve which travels to the brain stem, the very top of the spinal cord, located at the very center of the brain. There, each axon connects (synapses) with a cell or cells, and the axon of the receiving cell(s) travels another six inches to the back of the brain, the occipital lobe, where it synapses with a brain cell(s) to produce what we call vision.

Therefore, the major functions of these parts of the visual system are composed by:

Cornea: Refracts light rays
Pupil: Controls the amount of light entering the eye
Lens: Refracts light rays
Vitreous: Light traverses this space
Retina: Converts light energy to electrical energy
Optic Nerve: Transmits electrical energy from the retina to the brain stem
Brain Stem: Intermediate 'relay station' for visual fibers
Occipital Cortex: Final destination. Converts electrical energy to visual images

A "Perfect Eye" would therefore have:

a clear and unobstructed path from the front of the eye to the back of the eye.
the proper balance between the length of the eye and the curvatures of the three refracting surfaces.
properly functioning cells in the retina and brain which allow the conversion of light energy to electrical energy, the transmission of this energy, and the interpretation of the energy into what we call vision.

Unfortunately, most people do not have "perfect eyes".

Eyes that are too long or have too much refracting power (from the cornea and the lens) are nearsighted eyes, as images are focused in front of the retina. The image received by the retina is not a 'dot for dot' representation of what the image viewed by the eye. Instead, each of these 'dots' of light becomes enlarged to form a 'disc' of light with a consequent spread of the dot image to adjacent parts of the retina. This is what causes blurring of vision.

The opposite results when eyes or too short or have too little refracting poser. These eyes are farsighted, as images are focused (or would be) behind the retina. The same type of dot to disc representation occurs.

When light rays that are vertically oriented are not refracted the same amount as the light rays that are horizontally oriented, this condition is called astigmatism. An example would be when that eye looks at a building that is built as a square, it would appear as a rectangle with different vertical and horizontal dimensions being visualized. This example refers to strictly vertical (90 degrees) and strictly horizontal (0 degrees); astigmatism can occur at any angle between 0-180 degrees.

On a more dynamic level, the eye can possess no refractive error whatsoever but is unable to adjust to near images by increasing its refractive powers. This condition is termed presbyopia and normally affects persons in their 40s and early 50s. The mechanisms within the eye that can increase the curvature of the lens (accommodation) become less efficient and external plus lenses are necessary to bring the near images into focus.

The eye is truly like a camera because it not only requires proper focusing (refraction) but it requires a clear media through which light rays must pass. Any loss of clarity of the structures through which these light rays must pass will interfere with their successful interpretation within the visual cortex of the brain. Examples of disorders which might cause this scattering or absorption of light rays are opacities or swelling of the cornea (scars, edema, abrasions, etc.), opacification of the lens (cataract), and cloudiness of the vitreous (hemorrhage or inflammation.)

Also, the receiving tissue, the retina must be functioning properly, as opposed to aged related macular degeneration, in which there is deterioration of the most important part of the retina, the macula, which is responsible for our finest and our reading vision.

The range of patologies which can be treated with Laser Eye Surgery are:

Myopia (nearsightedness): -0.75 diopters to -10.0 diopters
Hyperopia (farsightedness): +0.75 diopters to +5.0 diopters
Astigmatism (associated with myopia): 0 to 4.0 diopters
Presbyopia (the eye's diminished ability to focus that occurs with aging).

Traditionally, many of these conditions were often treated with prescription glasses or contact lenses. Today, a number of innovative Laser Eye Surgery procedures are widely available.
There are three main types of Laser Eye Surgery:

PRK (Photo Refractive Keratectomy) has been the standard eye laser surgery for many years.
It involves the complete removal of the epithelium or the outer layer of cells on the eye, with the use of a "cold" laser light.
PRK is mostly used on patients with low to moderate amounts of Myopia Astigmatism.
Below you can watch a video showing a PRK surgical intervention:

LASEK (Laser Assisted Sub-Epithelial Keratectomy) or EPIFLAP (Laser Assisted Epithelial Keratomileusis) surgery involves the fractional removal of the epithelium to reveal the cornea, which is then firmed or reshaped by a laser. The outer layer of cells is then pushed back, and the eye heals shortly after.
LASEK is used on patients with low to moderate amounts of Myopia or Astigmatism.
Below you can watch a video showing a LASEK surgical intervention:

LASIK (Laser Assisted in Situ Keratomileusis) is the newest and most popular type of eye laser surgery. Initially developed by Spanish ophthalmologist José Barraquer, with this procedure a thin layer of the eye's cornea is sliced off to create a flap. This enables the laser to target the tissue underneath. The flap is simply replaced and grows back naturally. Vision is restored almost immediately.
LASIK is usually used on patients with severe Myopia (nearsightedness): -0.75 diopters to 10.0 diopters.
Below you can watch a video showing a LASIK surgical intervention:

All of these treatments have been approved for use in many countries around the world and are therefore considered to be safe.
But it must be taken into account that all types of surgery does involve risks and eye surgery is no different.
There have been cases during which patients have suffered major complications and required cornea transplants following laser treatment.

Not everyone can have laser eye surgery. Although eye laser surgery is usually suitable for healthy adults and can be performed on virtually any eye, sometimes it is not advisable.
Several factors could influence negatively the outcome of these operations:
AGE: It is advisable that a person undergoing Laser Eye Surgery should be at least eighteen years old. It is assumed that the refractive error (prescription) of the patient will be fairly stable at this time.
However, there's no upper age limit for Laser Eye Surgery eligibility, since it does not affect the nature or outcome of the surgery.
ENDOCRINE: Hormone fluctuations can affect the refractive error of a person's eye. Surgery during a period of such instability would probably produce changes which would not be correct once the endocrine system returns to normal. Therefore, Laser Eye Surgery is not recommended for women who may be pregnant, nursing, or undergoing changes in oral contraceptive therapy.
HEALTH: Because the cornea is composed of a matrix of collagen fibers, the same material which comprises tendons and other connective tissue, people who have autoimmune disorders, e.g., rheumatoid arthritis, Sjogren's Syndrome, Systemic Lupus Erythematosis, etc., may be at risk for unpredicted changes following surgery. Other medical problems, such as diabetes mellitus, high blood pressure, heart problems, etc. do not affect the outcome of Laser Eye Surgery surgery.
HERPES VIRUS INFECTION: A history of herpes simplex infection of the eye may be a contraindication to Laser Eye Surgery surgery. It is believed that the virus may permanently reside in nerve cells outside the eye and that any kind of surgery might reactivate an infection. However, this area is undergoing change. Studies are being done to see if treatment with antiviral medication prior and after the operation might prevent such a recurrence. Herpes infections in other parts of the body do not pertain to qualifying for Laser Eye Surgery surgery.
PUPIL SIZE: The excimer lasers currently treat an area of the cornea that measures about 7 to 8 mm in diameter. Therefore, it is important that the pupil size be less than the area of treatment. Most of the reported difficulties with glare experienced by patients come from those with pupillary size irregularities.
REFRACTIVE ERROR: Most persons are either nearsighted or farsighted with some degree of astigmatism. After age of 40, people also experienced difficulties with focusing at near, a condition known as presbyopia.
Although none of the procedures described above can be used for this condition, for such patients there exists laser thermal keratoplasty (LAPR), in which mild laser heat is used in a three-second procedure to shrink collagen in the periphery of the cornea to steepen the eye's surface for correction of near vision in farsightedness or presbyopia.
End results are similar to Conductive Keratoplasty (CK), which is also used to treat this condition. This procedure uses radio frequency energy to apply heat to very tiny spots around the cornea.

External links

Acne Laser Treatment Proves Successful

Despite their prevalence, acne scars have always been a condition notoriously difficult to treat.
In the past, Dermatologists have used all kinds of treatments, such as excision, punch grafts, dermabrasion and chemical peels, with a low degree of success.
It wasn't until the late 1980's that experiments using pulsed dye lasers were initiated on thickened, overgrown scars.

Dr. Alster, MD, Washington Institute of Dermatologic Laser Surgery and Georgetown University and her colleagues have since then reported prolonged improvement in the appearance of most scars after pulsed dye laser treatment. "Clinical assessments and skin surface texture analyzes using a computer image analyzer showed that the laser-irradiated scars approximated normal skin characteristics."

Clinical research over the years has led to textural improvements of both thickened and deeply colored red scars. "After one or two pulsed dye laser treatments, a 57% to 83% improvement was observed. Facial acne scars have been very responsive to this treatment."

Research has shown that combining the use of the pulsed dye technology with carbon dioxide laser vaporization was found to provide improvement in non-reddened, minimally thickened scars. Atrophic acne scars where there is a breakdown of the skin, have been found to respond most favorably to carbon dioxide laser resurfacing. The number of treatments necessary depends on the type of lesion and each individual's collagen and wound healing response. Usually two or more treatments are needed for hypertrophic (thick) acne scars.

Advances in laser technology have progressed so rapidly during the past decade that successful treatment of many cutaneous concerns and congenital defects, including vascular and pigmented lesions, tattoos, scars, and unwanted hair-can be achieved.
The demand for laser surgery has increased substantially by patients and dermatologists alike as a result of the relative ease with which many of these lesions can be removed, combined with a low incidence of adverse postoperative sequels.
Refinements in laser technology and technique have provided patients and practitioners with more therapeutic choices and improved clinical results. In this review, the currently available laser systems with cutaneous applications are outlined, with primary focus placed on recent advancements and modifications in laser technology that have greatly expanded the cutaneous laser surgeon's armamentarium and improved overall treatment efficacy and safety.

The pulsed dye laser procedure is typically performed on an outpatient basis without general anesthesia. Local anesthesia is usually administered with a topical anesthetic cream, intralesional injections or nerve blocks. Adjacent, non-overlapping laser pulses are delivered over the scars. The immediate result may produce a purplish coloring. The treated scars are then evaluated 6-8 weeks later, where another treatment, at the same or slightly higher strength may be necessary.

Local, regional nerve block, or intravenous sedation may be required for CO2 laser resurfacing of atrophic acne scars depending on the extent of damage. Follow-up examinations and skin cleanings are scheduled often during the first postoperative week and patients are encouraged to keep the area moistened with healing ointments and/or cooled compresses. Early evaluation and intervention are important in order to prevent long-term scarring.

The American Academy of Dermatology is the largest medical society representing physicians who specialize in treating skin, hair and nail conditions.

Dr. Tina Alster is widely recognized as one of the world's leading authorities on dermasurgery.

External Links

American Academy of Dermatology
Washington Institute of Dermatologic Laser Surgery
Lasers in dermatology: Four decades of progress
Laser Resurfacing Reviews
Laser and intense pulsed light (IPL) therapies for acne scars, injury scars and skin blemishes

Manuscripts by Dr. Tina Alster

Laser Skin Resurfacing

Non Abrasive Laser and Radiofrequency Treatments

Scar Revision

Photodynamic Therapy to beat cancer

Photodynamic Therapy (PDT), is a new procedure to remove skin tumors without the need for an anaesthetic or even a hospital stay.

PDT uses a class of drug which starts working only when activated by light. This then produces a damaging form of oxygen that destroys tissue.

For internal cancers, the drug is injected a few days before treatment. Once injected, the patient must be careful to avoid bright light, such as fluorescent light and sunlight, until treatment has taken place.

During treatment, a narrow beam of red light, usually from a laser, is shone onto the tumour, activating the drug and killing the malignant cells. It takes only a few minutes and the patient can go home immediately.

Patients describe a 'tingling' sensation as the light is applied, but this usually dissipates after half an hour.

The National Institute of Health and Clinical Excellence has recently approved PDT for the treatment of nonmelanoma skin tumours. 'There are no major safety concerns,' its guidelines state. 'Cosmetic outcomes...(are) good or excellent.'

For skin cancers, the drug is applied in the form of a cream. The patient is then bathed in laser light, but only the cream covered area reacts.

The main PDT research centre is at the National Medical Laser Centre in University College Hospital, London (UCH), where they are investigating other uses of the therapy. Essentially, it should work well anywhere inside the body where an endoscope - an examination tube carrying a light - can get to.

'Besides treating skin cancer, we've also seen more than 600 patients with tumours in the mouth and neck,' says Stephen Brown, professor of Laser Medicine and Surgery at UCH. 'It works best when the cancer isn't too far advanced.'

Light can also be taken down the esophagus - the tube from the throat to the stomach. Acid escaping from the stomach can damage cells that line the bottom of the esophagus, turning them pre-cancerous - a condition known as Barrett's esophagus.

A trial has found PDT is twice as effective in treating pre-cancerous cells in the esophagus as anti-acid drugs (a conventional treatment).

One of the main advantages of PDT is the lack of side-effects. While chemotherapy drugs have to be infused over weeks and often cause nausea, as well as damaging fast-growing cells (the reason why patients lose their hair) and the gut lining, PDT's side-effects are nearly always relatively mild and usually limited to some pain, swelling and nausea.

Furthermore, any surrounding healthy tissue that is damaged grows back in a matter of weeks. Healing is quick because, unlike radiotherapy, PDT doesn't damage the underlying collagen scaffolding of healthy cells, making repair much easier.

If pre-cancerous cells do reappear, PDT can be done twice more and then, if necessary, there is still the option of the operation.

'Sometimes PDT can be used to salvage the situation when surgery, chemo or radiation has failed,' says Professor Brown. 'But it makes much more sense to use it first.'

Yet despite its apparent benefits, PDT is still regarded with skepticism by conventional cancer experts. Cancer charity BACUP describes it as 'not yet established...still being tested', and warns about possible side-effects.

The history of the treatment is partly to blame. 'When it first appeared in the 1980s, various wild claims were made for it,' Brown says. 'I think some people are still distrustful because of that.'

Since then, however, the drugs and techniques have been refined and trials show its benefits.

Another possible reason for PDT's marginalization is that it requires a new approach. 'If you are a cancer surgeon or a radiologist, or you have a unit set up to do chemotherapy, you've got a huge investment in existing technology, and PDT doesn't use any of it,' says Bown.

'But we are not trying to put anyone out of business. The beauty of PDT is that it is simpler, cheaper and less invasive to begin with, but if it doesn't work, the more conventional techniques can also be used.'

Research is already underway at the UCL unit to add PDT to the list of options for prostate cancer. This is because of changing attitudes to treatment.

'In the past, as soon as cancer was detected, the advice was to remove the whole organ,' says Brown. 'That usually got rid of the cancer, but it often left the patient impotent or incontinent.

'Now the trend is to treat the main tumour but leave smaller ones and then monitor the patient carefully. PDT can be repeated if the cancer rears its head again.'

Removing a cancer with minimum surrounding damage is what makes PDT so effective. But there is a difference between using PDT on body surfaces and in the prostate, which is not accessible to an endoscope.

'You have to locate accurately the tumour, which you can't do with scans,' says Brown. 'So we may have to take up to 20 biopsies.' However, this is still only a research procedure.

There are only two or three other major centres researching PDT in the UK and while experts still differ on when PDT is appropriate, everyone agrees there should be more trials to test it.

More Info:

Definition of Laser Therapy

Definition

Photobiomodulation, also known as low level laser therapy (LLLT), cold laser therapy, and laser biostimulation, is a controversial medical and veterinary technique in which exposure to low-level laser light is claimed to enhance tissue growth and have other beneficial effects.
The technique is also known by the more ambiguous terms phototherapy and laser therapy, which may also be used to describe other medical techniques.

Credit for the development of laser theory is generally given to Albert Einstein. In his theory "Zur Quantum Theories der Strahlung", published in 1916, he first used the name stimulated emission.

The word LASER is an acronym for Light Amplification by Stimulated Emission of Radiation.

In 1967 a few years after the first working laser was invented, Endre Mester in Semmelweis University Budapest, Hungary wanted to find out if laser light could cause cancer. He took some mice, shaved the hair off their backs, divided them into two groups and gave a laser treatment with a low-powered ruby laser to one group. They did not get cancer and to his surprise the shaved hair grew back more quickly on the treated group than the untreated group. That was how "laser biostimulation" was discovered.

Clinical applications

Clinical applications include treating soft tissue injuries and chronic pain, aiding smoking cessation, wound healing and nerve regeneration, and possibly even resolving viral and bacterial infections.

The best documented laser type is the HeNe laser (Helium-neon, visible red light, 632.8 nm, continuous or chopped, usually non-polarized but with very high degree of coherence). The HeNe-laser is a gas laser, powered with high voltage and hence usually voluminous and expensive per milliwatt. Available on the market in Europe since 1975. As an alternative one could choose an InGaAlP-laser diode laser (Indium gallium aluminum phosphide laser, visible red light, semiconductor laser type, and usually just named Indium laser) with wavelength 635 to 700 nm. The most common wavelength is 650 nm. The Indium lasers are cheaper per milliwatt than the HeNe-laser. Their light is polarized but less coherent light. Available since 1990. Both HeNe and Indium lasers seem to be best on problems in skin and mucosa (superficial).

The second best documented laser type is the GaAs-laser (invisible infrared, 904 nm, semiconductor type, always super-pulsed with very high peak power, often polarized but less coherent). Available on the European market since 1985. This laser is best suited for deep lying problems such as back, shoulders, spine and other joints, fibromyalgia, whiplash injury, lymph edema, trismus etc.

For the GaAs-lasers there is one extra factor to be aware of. Traditionally these lasers have low output at low pulse frequencies and high at high frequencies. Often the average output power is more or less proportional to the frequency set. This means that if the average output is 10 mW at 10,000 Hz, it is 1 mW at 1000 Hz and 0.1 mW at 100 Hz etc. Such a laser is more or less useless on all frequency settings except 10.000 Hz.

However, there are GaAs-laser (904 nm) instruments available where the output average power is independent on the frequency. This is very valuable as the dose given then simply is proportional to the treatment time. Such lasers are pulse train modulated.

The most commonly sold laser type today is found within a group of lasers - the so called GaAlAs-lasers. In this group there are lasers from about 750 nm and up to 980 nm. Originally the wavelength was 820 or 830 nm, invisible, infrared. Today there are two main types, the 808 nm one, usually produced in Europe and recently also in the USA and the 890 nm one, usually produced in Russia. The reason why so many lasers of this type are offered today is that they are the producers’ favorite; they are cheap (per mW) and easy to drive electrically. They can be made with powers up to hundreds of watts, e.g. for surgery and hair removal and in laser therapy they are usually emitting 100 mW and upwards. The light is invisible and always polarized. It is either continuous or chopped. These lasers are often suggested for the treatment of tendonitis and tinnitus.

Apart from this, also strong (surgical/aesthetic lasers, such as CO2-, Ruby-, Nd:YAG-, Ho:YAG and some other types) can be used as therapeutic tools. Just set lower power.

For deep lying problems the GaAs laser is penetrating best (because of its high peak power) and for problems in skin and mucosa the HeNe laser is the most effective one (due to the high degree of coherency). The 808 or 890 nm lasers are more all-round types and often battery powered. There are single- or multi probes. For a multi probe, all the lasers should have the same wavelength (same laser type).

Effects of Laser Therapy

Certain wavelengths of light at certain intensities (delivered by laser, LED or another monochromatic source) will aid tissue regeneration, resolve inflammation, relieve pain and boost the immune system.
The exact mechanism is still being explored and debated but it is agreed that the mechanism is photochemical rather than heat-related.
Observed biological and physiological effects include changes in cell membrane permeability, up-regulation and down-regulation of adenosine triphosphate and nitric oxide.

Contentious areas are: "best" wavelength, dose, dose-rate effects, beam penetration, the role of coherence and pulses (peak power and repetition rates). Laser average power is typically in the range of 1-500 mW; some high peak power, short pulse width devices are in the range of 1-100 W with typically 200 ns pulse widths. The average beam irradiance then is typically 10 mW/cm2 - 5 W/cm2.
The wavelength is typically in the range 600-1000 nm but some research has been done and products are available outside this range.

Side effects

There appear to be no safety concerns in its application for therapy in people or animals, but the operator and patient should wear appropriate protection for the eyes (dense filter spectacles) in case of accidental or reflected exposure, and the laser beam should never be directed at the eyes.

External links

Selected Laser Therapy Abstracts
Effects of Low-Intensity Polarized Visible Laser Radiation on Skin Burns: A Light Microscopy Study.	Effects of Pulse Frequency of Low-Level Laser Therapy (LLLT) on Bone Nodule Formation in Rat Calvarial Cells
Laser therapy of duodenal ulcers: effect on indices of microcirculation, cell membrane permeability and homeostasis of trace elements	Effects of Low-Level Laser Therapy (LLLT) of 810 nm upon in Vitro Growth of Bacteria: Relevance of Irradiance and Radiant Exposure
Photostimulation of coronary arteries with low power laser radiation: preliminary results for a new method in invasive cardiology therapy	Effect of the Clinical Application of the GaAlAs Laser in the Treatment of Dentine Hypersensitivity
[Low power laser biostimulation in the treatment of bronchial asthma].	Effect of Low-Power Radiation (Helium/Neon) upon Submandibulary Glands
Effects of the 650 nm laser stimulation, utilizing clinical doses for proliferation of cultured human fibroblasts.	Low-Level Laser Irradiation Attenuates Production of Reactive Oxygen Species by Human Neutrophils
Transmeatal cochlear laser (TCL) treatment of cochlear dysfunction: a feasibility study for chronic tinnitus	Effect of NASA Light-Emitting Diode Irradiation on Molecular Changes for Wound Healing in Diabetic Mice
Effects of Low-level Laser Therapy in HIV/AIDS-positive Patients After Exodontic Procedures.	Influence of Linearly Polarized Near-Infrared Irradiation on Deformability of Human Stored Erythrocytes
Role of Gallium Arsenide Laser Irradiation at 890 nm as an Adjunctive to Anti-tuberculosis Drugs in the Treatment of Pulmonary Tuberculosis	The Comparison of Effects between Pulsed and CW Lasers on Wound Healing
Usefulness of Low-Level Laser for Control of Painful Stomatitis in Patients with Hand-Foot-and-Mouth Disease.	NASA Light-Emitting Diodes for the Prevention of Oral Mucositis in Pediatric Bone Marrow Transplant Patients
Low-Intensity Near-Infrared Laser Radiation-Induced Changes of Acetylcholinesterase Activity of Human Erythrocytes.	Effects of 630-, 660-, 810-, and 905-nm Laser Irradiation Delivering Radiant Exposure of 1-50 J/cm2 on Three Species of Bacteria in Vitro
Effect of 830-nm Laser Light on the Repair of Bone Defects Grafted with Inorganic Bovine Bone and Decalcified Cortical Osseous Membrane.	Contraindications in Noninvasive Laser Therapy: Truth and Fiction
Low Level Laser Therapy-a conservative approach to the burn scar?	Low-Intensity Laser Therapy/Combined Phototherapy in the Management of Chronic Venous Ulceration: A Placebo-Controlled Study
Low-level laser therapy stimulates bone-implant interaction: an experimental study in rabbits.	TI Therapeutic photobiomodulation for methanol-induced retinal toxicity.
Dose and Wavelength of Laser Light Have Influence on the Repair of Cutaneous Wounds.	Polychromatic LED Therapy in Burn Healing of Non-diabetic and Diabetic Rats
Selected laser therapy abstracts from April 2004.
Effects of Low-level Laser Therapy in HIV/AIDS-positive Patients After Exodontic Procedures.	Effectiveness of low-level laser therapy in temporomandibular disorder.
Effects of infrared and low-power laser irradiation on cell viability, glutathione and glutathionerelated enzyme activities in primary rat hepatocytes.	Laser photostimulation accelerates wound healing in diabetic rats.
Laser light prevents apoptosis in Cho K-1 cell line.	Comparison of the photostimulatory effects of visible HeNe and infrared GaAs lasers on healing impaired diabetic rat wounds.
Non-pharmacological approaches to chronic headaches: transcutaneous electrical nerve stimulation, laser therapy and acupuncture in transformed migraine treatment.	Efficacy of 300 mW, 830 nm laser in the treatment of chronic pain: a survey in a general practice setting.
Efficacy of low level laser therapy in myofascial pain syndrome: an algometric and thermographic evaluation.	Photobiological modulation of cell attachment via cytochrome c Oxidase.
The clinical efficacy of low-power laser therapy on pain and function in cervical osteoarthritis.	Effects of low-power laser exposure on masseter muscle pain and microcirculation.
cDNA microarray analysis of gene expression profiles in human fibroblast cells irradiated with red light.	Effects of infrared and low-power laser irradiation on cell viability, glutathione and glutathionerelated enzyme activities in primary rat hepatocytes.
Non-pharmacological approaches to chronic headaches: transcutaneouselectrical nerve stimulation, lasertherapy and acupuncture in transformed migraine treatment	Efecto de la estimulación láser de 650 nm, utilizando dosis de uso clínico, sobre la proliferación de fibroblastos humanos cultivados.
Transmeatal cochlear laser (TCL) treatment of cochlear dysfunction: a feasibility study for chronic tinnitus.	[Low power laser biostimulation in the treatment of bronchial asthma]
Photostimulation of coronary arteries with low power laser radiation: preliminary results for a new method in invasive cardiology therapy.	Usefulness of Low-Level Laser for Control of Painful Stomatitis in Patients with Hand-Foot-and-Mouth Disease.
Effect of 830-nm Laser Light on the Repair of Bone Defects Grafted with Inorganic Bovine Bone and Decalcified Cortical Osseous Membrane	Low-Intensity Near-Infrared Laser Radiation-Induced Changes of Acetylcholinesterase Activity of Human Erythrocytes.

LED Pulses Reduce Radiation Effects on Skin in Breast Cancer Patients

Following radiotherapy for breast cancer, women exposed to pulses of low-energy non-thermal light-emitting diode (LED) photomodulation had significantly less dermatitis than controls.
Action Points

Eighteen of 19 women who had radiotherapy for breast cancer followed by LED photomodulation had only mild or no radiation dermatitis, an adverse effect that can affect regimen schedules, said M. Maitland DeLand, M.D., of Louisiana State University and a radiation oncologist of Lafayette, La.

In contrast, all 28 controls not given the LED treatment had some degree of skin reactions following radiotherapy, she said at the American Society for Laser Medicine and Surgery meeting here.

LED photomodulation is widely used in cosmetic dermatology for improving skin healing and appearance. The apparatus consists of light-emitting diodes in a specific array that emit a non-thermal, low energy light at a pulsating frequency.

"The pulses stimulate at the cellular level skins cells such as fibroblasts to repair themselves to build up the collagen," Dr. DeLand said in an interview. "The other thing is that they interfere with the inflammatory pathways that break down the skin and cause erythema."

Dr. DeLand said that radiation-induced dermatitis occurs to some degree in about 80% to 90% of women during adjuvant radiotherapy following lumpectomy.

The reactions may include dryness, epilation and faint erythema early in the course of therapy, often progressing to mild, moderate or significant erythema, dryness, hyperemia, dry desquamation and skin thickening after two to 4.5 weeks of therapy. In the most severe cases, patchy and confluent moist desquamation with loss of epidermal barrier and delayed healing.

Women with severe dermatitis have raw, painful skin and may require interruption of therapy, she added.

Dr. DeLand and colleagues looked at the potential for LED photomodulation to ameliorate skin reactions in women who received intensity modulated radiation therapy following breast conserving surgery in women with stage I or II disease.

All women had single lymph node sampling or axillary dissection, and some had received chemotherapy prior to radiotherapy.

A total of 19 women received daily radiation therapy followed by LED treatment, in which 100 pulses of light at 0.15 joules/cm2 for 250 ms each are delivered to the irradiated breast (the treatment takes about one minute). Women in this group used only a dry skin ointment (Aquaphor) after their daily sessions.

Controls were 28 age-matched women who underwent the same radiation therapy protocol but no LED photomodulation. These women also were allowed to use Aquaphor and other creams as required for cutaneous reactions.

All patients had weekly evaluation of the irradiated skin.

The investigators found that seven of the women who had received LED photomodulation had no skin reactions, 11 had only mild (Grade 1) reactions, and one had moderate (Grade 2) radiation-induced dermatitis.

In addition, none of the patients who underwent photomodulation experienced moist skin reactions, although one patient in this group had inflammation severe enough to require interruption of radiotherapy. One patient with a Grade 1 reaction also required interruption of therapy due to an intermammary yeast infection.

Among patients who received the LED therapy but still had grade 1 reactions, the reactions were delayed one to two weeks beyond the time that erythema would be expected to develop, the investigators noted.

In contrast, Dr. DeLand said, all patients in the control group had some type of skin reaction following radiation. Four patients had mild radiation dermatitis, 18 han moderate dermatitis and six had serious skin reactions.

Nineteen of the 28 patients who did not receive LED photomodulation required temporary interruption of therapy because of erythematous reactions and moist desquamation.

Dr. DeLand said that although her colleagues in dermatology and cosmetic surgery are well versed in the skin-repair properties of photomodulation, many of her radiation oncology colleagues were unfamiliar with it.

"The important thing for my breast cancer patients is that they've been through surgery, some of them have infections, and then they get chemo, and especially when they get a taxane or an Adriamycin [doxorubicin]-based drug, that photosensitizes the skin, and when you start doing the radiation their skin reaction is typically worse.

"So many of those women, their skin breaks down -- it peels -- and if you've ever had a moist skin reaction, you know that it's miserable, " Dr. DeLand said.

In all, six of the women in the LED treatment group were available for follow-up at three months, and five were available at six months post therapy. In all of these patients the surgical scar was barely visible, skin texture and pigment were excellent, and the breast tissue was smooth and supple, without dryness, she noted.

In contrast, at three months after therapy, women who did not receive LED photomodulation have typical late radiation effects, including atrophy, telangiectasias, and hyper- or hypo-pigmentation. Some women also had radiation-induced fibrosis, with long-term induration, edema, and dermal thickening.

When LED photomodulation is used with a neutral pH moisturizer to keep skin from drying out, it offers a "quick, painless and effective solution to combat the skin reactions that may interrupt and compromise treatment," she said.

Source: http://www.medpagetoday.com
Primary source: American Society for Laser Medicine and Surgery
Source reference: DeLand MM. "Pilot Study of LED Photomodulation to Reduce Inflammation Following Radiation Treatment of Breast Cancer."
Late-breaking abstract presented April 7, 2006.

Alcohol, Autism, Lasers

NewsCenter 5's Heather Unruh reported that lasers could help women suffering the side effects of breast cancer radiation; new statistics about autism have been released; and for women, a drink or two each day may not be as bad as once thought.

Women and Alcohol

Drinking can get some women thinking, according to new research.

Researchers at Columbia University studied about 3,300 women and found those who had up to two drinks a day scored 20 percent higher on a cognitive test than women who drank less than one drink a week.

The study did not find any link between alcohol and brainpower in men.

Autism Stats

The odds of a child being diagnosed with autism are much higher than previously thought -- just one in 166, according to new statistics.

The group Autism Speaks is launching a new campaign to draw awareness to the fastest growing developmental disorder in the United States. The group encourages parents to see a pediatrician if their child doesn't meet developmental milestones.

There is no way to prevent autism, but with early diagnosis and treatment, the long-term effects of the disorder can be reduced.

Laser and Cancer Treatment

Women undergoing radiation treatment for breast cancer often have to deal with red, itchy skin reactions called radiation dermatitis. But a simple light-based therapy introduced Thursday at a meeting of laser specialists in Boston may help relieve their pain.

LED photo-modulation works by activating skin cells with pulses of low-energy light. The light helps increase collagen production while decreasing inflammation.

"What this does is it keeps their skin in tact so they can perform their normal tasks without a lot of discomfort," said radiation oncologist Dr. M. Maitland DeLand.

In a small study group, LED photo-modulation lowered skin reactions in 95 percent of patients. Doctors said the treatment allows breast cancer patients to focus on treating their cancer instead of a painful side effect.

Source:
http://www.thebostonchannel.com

Laser, light treatments expanding, combining modalities

Key developments from the recent American Society for Laser Medicine and Surgery (ASLMS) meeting include broader applications for existing devices and the growing availability of treatments that combine modalities.

Dr. Alster
"While fractional laser surfacing (Fraxel, Reliant Technologies) is nothing new to those physicians who have been using it over the last couple of years, it's still novel to the majority of attendees, including many experienced laser specialists," says Tina S. Alster, M.D., director, Washington Institute of Dermatologic Laser Surgery and clinical professor of dermatology, Georgetown University Medical Center.

According to a study Dr. Alster presented, clinical results obtained after three Fraxel treatments remained evident for 12 months thereafter (Tanzi EL, Alster TS. Lasers Surg Med. 2006; suppl.18:25).

"What is happening is that longer follow-up studies are being performed on rejuvenation patients, including those treated in nonfacial sites," Dr. Alster says.

As with other technologies, she adds, physicians are beginning to use Fraxel for additional indications, including acne scars and stretch marks.

Dr. Zachary
"Fractionated delivery of laser energy is a major advance in laser surgery, and we're already seeing other companies developing devices which deliver intense amounts of energy to a fraction of the skin's surface," says Christopher Zachary, M.D., professor and chairman of dermatology at the University of California, Irvine, and program chair of the meeting.

Ultimately, he predicts these developments will be as important to laser surgery as are cooling technologies.

PLASMA SKIN RESURFACING

The meeting also represented many attendees' first in-depth exposure to plasma skin resurfacing (Portrait PSR3, Rhytec), Dr. Alster says.

In addition to extended reporting on facial rejuvenation results, presenters revealed new research into the device's safety and efficacy on the neck, chest and hands.

"Plasma skin resurfacing packs a bit more punch than does Fraxel, but it does require some postoperative recovery by patients," reports Dr. Alster, who co-authored a study which found 40 percent to 60 percent long-standing improvement in 30 sites on the neck, chest and hand after a single treatment at low energy settings of either 1, 1.5 or 1.8 joules (Alster TS, Tanzi EL. Lasers Surg Med. 2006;suppl. 18;20).

"This is just the beginning of using plasma skin resurfacing off-face," Dr. Alster says, "but we clearly showed that it was safe using the technique and relatively low fluences applied. Further research is necessary to determine the effect of multiple treatment sessions, as well as optimal device parameters, treatment intervals and longevity of results."

CELLULITE

"Cellulite is a pervasive problem among post-pubertal women," Dr. Alster says, "and we still don't have a great treatment for it."

Based on a review of studies done to date, she says the VelaSmooth (Syneron) device, with a combination of radiofrequency, infrared light and mechanical negative pressure massage, appears to be more effective than TriActive (Cynosure), which combines a diode laser, suction and rollers, though other technologies could emerge.

"There's little doubt that cellulite treatment remains imperfect, and that some sort of combination treatment — whether it's radiofrequency, light and massage or another combination, including perhaps ultrasound or mesotherapy — represents the wave of the future," Dr. Alster explains.

HAIR REMOVAL

As for hair removal, Kathleen Gilmore, M.D., presented a review of more than 1,600 such treatments (1,092 with LightSheer diode laser, Lumenis; 545 with Aurora IPL and radiofrequency system, Polaris) occurring over three months in a high-volume laser hair removal center.

Researchers noted only two adverse events in the LightSheer group and none in the Aurora group, according to Dr. Gilmore, who is corporate medical director for American Laser Centers.

Laser epilation is a very safe procedure, "as long as one has a good, safe protocol," she says.

To that end, she attributes American Laser Centers' low adverse event rate to factors including fine-tuned skin typing, which considers elements such as heredity and hair color, and careful pre-treatment testing that focuses on the body's left side, which suffers more sun exposure when Americans drive.

Biostimulation through light-emitting diodes (LEDs; GentleWaves, Light BioScience) also continues to progress, Dr. Alster says. "When this technology was first introduced stateside," she observes, "there didn't seem to be a lot of clinical or basic science there."

But with increasing use, physicians are noticing subtle changes, which the research of David H. McDaniel, M.D., of Virginia Beach, Va., is beginning to quantify, she says.

Along with providing noninvasive rejuvenation, Dr. Alster says the technology appears especially helpful for minimizing erythema after laser procedures and sunburns. Its anti-inflammatory effect also makes it effective against dermatitis, she adds.

Dr. Zachary says, "There's a huge amount of interest in LEDs," and much more information available about the way in which these nonthermal lasers can affect fibroblast, vascular and other elements of the skin. "It would appear that these devices reduce erythema and can stimulate all sorts of cytokines with the goal of promoting collagen remodeling or rejuvenation," he adds.

Regarding other technologies, Dr. Zachary says, "The monopolar radiofrequency device (ThermaCool™, Thermage®) over the last several years has changed dramatically the way in which energy is delivered."

Specifically, he says its manufacturer now offers faster and smaller tips that create the potential for eyelid treatments.

Drs. Alster and Zachary say the Cynergy laser (Cynosure), which delivers two wavelengths (595 nm and 1,064 nm) in sequential pulses for vascular treatments, also merits mention.

"With the first pulse, one can change, within microseconds, the absorption characteristics of the blood to prepare for the second pulse, which will then cause a profound, deeper benefit to the vascular malformation," Dr. Zachary explains.

Thanks to increasingly sophisticated engineering, either through combining laser beams or refining intense pulsed light (IPL) devices through filtering and pulsing systems, Dr. Zachary says, "These are exciting times for laser surgeons."

Disclosures:
Dr. Zachary is an unpaid consultant for Reliant Technologies.
Dr. Alster is an unpaid member of Syneron's medical advisory board.

Multi-Use Lasers

They can reshape the cornea to give patients 20/20 vision. They can smooth out wrinkles. They can reduce neck and back pain. They can even remove birthmarks.

And that's just the beginning.

Lasers can vaporize varicose veins, zap stubborn acne and get rid of unwanted hair. In the past decade, lasers also have been approved to unclog arteries, crush gallstones and repair damaged retinas.

Lasers are playing a growing role in medical care as technology has improved and doctors are finding new uses for the devices. "The industry is growing at record paces," says A. Jay Burns, a plastic surgeon in Dallas and former president of the American Society for Laser Medicine and Surgery.

Medical lasers use tubing to deliver highly focused beams of light that pass through a crystal or gas. The material the light passes through helps determine what the light energy does to the body.

Though lasers have made many inroads in medicine in the past decade, numerous other applications are now being tested.

Lasers are expected to play a greater role in diagnosing disease and helping identify cancerous tissue, Burns says. For example, studies are examining how lasers can be used in colonoscopies to help doctors immediately detect cancerous tissue rather than waiting days for a laboratory analysis. Researchers also are trying to see whether lasers can speed the healing of broken bones, help regenerate nerves in patients with injured spinal cords and help grow skin in burn victims.

"This is a compelling technology that's becoming easier to deploy," says John Ambroseo, CEO of Santa Clara, Calif.-based Coherent Inc., a major maker of medical lasers.

Costs — and sizes — shrink

Laser treatment procedures' low costs and the shrinking size of the devices have enabled spas and beauty salons to install them. But the rapid growth in the field has raised concerns about whether laser procedures are being overused and misused.

Many doctors have begun doing cosmetic laser procedures largely to augment their incomes, says J. Stuart Nelson, a surgeon and associate medical director of the Beckman Laser Institute at the University of California-Irvine. That has raised questions of whether doctors are going beyond their expertise. More than 50 medical specialties use lasers today, the American Society for Laser Medicine says.

"Lasers are not for everything," Nelson says. He recommends that people get laser procedures only from experienced medical doctors.

Nelson specializes in using a laser to remove port wine stain birthmarks or small lesions that often appear on the face. Previously, doctors had to use a painful procedure involving skin grafts to eliminate the birthmarks. Now they use a laser to destroy blood vessels under the skin while leaving healthy tissue alone. The birthmarks can be removed in a series of treatments that take five to 10 minutes.

The use of lasers in cosmetic medicine, such as hair removal and skin resurfacing, makes up about 40% of the $2.5-billion-a-year global medical laser systems market, according to a study by the market consulting firm Frost & Sullivan.

Dentistry is another big area for lasers. The Food and Drug Administration has approved lasers for teeth whitening and to help treat cavities.

Lasers work well with soft tissue in the mouth, such as in reducing gum around the tooth to prepare for installing a crown.

But there is no proof it works in other applications such as accelerating tooth whitening, says David Garber, a periodontist in Atlanta and clinical professor at the Medical College of Georgia School of Dentistry.

Removing cavities with lasers has not been widely adopted because the process is slower than the traditional method, Garber says. The only benefit of the laser is that people don't have to hear the sound of the dental drill.

Studies are trying to determine whether a laser can identify and then zap away dangerous bacteria around the teeth while leaving the healthy tissues alone. "We have no easy way of controlling aggressive periodontal disease, and this can be a very targeted approach," he says.

A potential pain fighter

Newer "cool" lasers are showing promise as the latest weapon to fight chronic pain. In 2001, the FDA approved the Erchonia laser for chronic pain. It works by stimulating the body's cells to regenerate, according to the manufacturer's studies.

"The results have been remarkable," says Mitchell Prywes, a physical medicine and rehabilitation doctor in Danbury, Conn. He uses the laser on patients who have neck and back pain. Patients come in for five- to 10-minute applications that often complement physical therapy.

"We can often see results in minutes where we see the patient's range of motion improve and it improves pain," Prywes says. The laser reduces chronic neck and back pain because it reduces inflammation and activates cells to improve the natural healing process, he says.

"The laser is very much the future of medicine," Prywes says.

He adds that while the lasers are extremely safe, precautions must be taken to keep laser light away from the eyes, those with pacemakers and pregnant women.

"It is not a panacea for everything, but it can have a dramatic effect in speeding healing," says Charlie Shanks, a vice president of laser manufacturer Erchonia Inc. of Dallas.

By Phil Galewitz, Special for USA TODAY

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Manuscripts by Dr. Tina Alster

Laser Skin Resurfacing

Non Abrasive Laser and Radiofrequency Treatments

Scar Revision

Definition

Clinical applications

Effects of Laser Therapy

Side effects

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