laser

laser

 [la´zer]

a device that transfers light of various frequencies into an extremely intense, small, and nearly nondivergent beam of monochromatic radiation in the visible or invisible spectrum, with all the waves in phase; capable of mobilizing immense heat and power when focused at close range, lasers act on tissues by photocoagulation and photodisruption and are used in surgery, in diagnosis, and in physiological studies.

argon laser a laser with ionized argon as the active medium and with a beam in the blue and green visible light spectrum; used for photocoagulation.

carbon-dioxide laser a laser with carbon dioxide gas as the active medium and that produces infrared radiation at 10,600 nm; used to excise and incise tissue and to vaporize.

excimer laser (excited dimer) a laser with rare gas halides as the active medium, used in ophthalmological procedures and angioplasty. The beam is in the ultraviolet spectrum and penetrates tissues only a small distance; it breaks chemical bonds instead of generating heat to destroy tissue.

holmium:YAG laser a laser whose active medium is a crystal of yttrium, aluminum, and garnet doped with holmium ions, and whose beam is in the near infrared spectrum at 2100 nm; used for photocoagulation and photoablation.

neodymium:yttrium-aluminum-garnet (Nd:YAG) laser a laser whose active medium is a crystal of yttrium, aluminum, and garnet doped with neodymium ions, and whose beam is in the near infrared spectrum at approximately 1060 nm; used for photocoagulation and photoablation.

Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

la·ser

(lā'zĕr),

1. (noun) A device that generates an intense, narrow beam of light created by bombarding an active medium (for example, CO₂, Nd:YAG, argon), with energy in the form of high-voltage electricity, high-intensity light, or radio frequency waves. By passing through a mirrored tube, the photons are released as a nondivergent ("collimated"), monochromatic (all one wavelength), coherent (all in phase) beam. Lasers are used in microsurgery, for cauterization, excision, and for a variety of diagnostic purposes. The wavelength delivered depends on the active medium excited; targetted tissues ("chromophores") are determined by the laser wavelength that they absorb. Laser dosage, or fluence, delivered is derived by dividing the energy delivered by the cross-sectional area of the beam (Joules/CM²). Lasers can be based on numerous chemical sources, gas, liquid, and solid, some of which are listed in the chart on p. 1051. Lasers are widely used in printers of text or x-ray images.
See also: chromophore.

2. (verb) To treat a structure with a laser beam.
See also: chromophore.

[acronym coined from light amplification by stimulated emission of radiation]

Farlex Partner Medical Dictionary © Farlex 2012

laser

Light amplification by stimulated emission of radiation, Physics A device that provides a focused beam of light with enough energy to cut or coagulate tissue Surgery A tool that focuses light into an intense, narrow beam to cut or destroy tissue Applications Microsurgery, photodynamic therapy, diagnostics Types of lasers Argon-405 nm wavelength, CO₂-630 nm, tunable dye-1600 nm, YAG-neodymium-yttrium-aluminum-garnet-10,600 nm. See Argon laser, Excimer laser, Holmium pulsed laser, Nd:YAG laser, PTP laser, Roller ball technique, Selective photothermolysis, Yellow krypton laser.

Lasers in medicine

Type/General uses  Specialty/Wavelength/Power or energy

Alexandrite DR, ENT, O, U/700-800 nm//≤ 1 J/pulse

Argon/Coagulation DN, DR, ENT, O, U/450-515 nm//≤ 6 W

CO₂/Cutting, vaporization C, DN, DR, ENT, GS, GY, NS, OS, U//10.6 µm/≤ 100 W

Diode GS, U/800 nm//≤ 50W

Er:YAG  DN, O/2.94 µm/≤ 1 J//pulse

Excimer C, O/193 nm/≤ 0.6 J//pulse

Holmium YAG C, O, OS/2.10 µm//≤ 60 W

Nd:YAG/Volume coagulation DN, DR, O/532, 1064 nm//≤ 0.5 J/pulse

Nd:YAG, CW C, DR, ENT, GI, GS, NS, OS, U/532, 1064, 1044 nm//≤ 125 W

Pulsed dye DR, O, U/504-620 nm//≤ 2 J/pulse

Ruby DR/694nm//≤ 2 J/pulse  

C–Cardiology, DN–Dentistry, DR–Dermatology, ENT, GI, GS–General surgery, GY–Gynecology NS–Neurology, O–Ophthalmology, OS–Orthopedic surgery, PS–Plastic surgery, PU–Pulmonology, U–Urology

McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.

la·ser

(lā'zĕr)

1. (noun) Device that concentrates high energies into an intense narrow beam of nondivergent monochromatic electromagnetic radiation; used in microsurgery, cauterization, and for a variety of diagnostic purposes.

2. (verb) To treat a structure with a laser beam.

[acronym coined from light amplification by stimulated emission of radiation]

Medical Dictionary for the Health Professions and Nursing © Farlex 2012

laser

Acronym for Light Amplification by Stimulated Emission of Radiation. A device that produces light of a single, precisely defined wavelength, in which all the waves are in phase with each other (coherent light). This allows the beam to be intensely concentrated, with little tendency to spread out, and permits focusing into a spot of microscopic size. The properties of the various lasers make them invaluable for a variety of medical and surgical purposes, and a many laser types, including argon lasers, various YAG lasers, carbon dioxide lasers, various pumped dye lasers and high-precision excimer lasers, are being exploited for this purpose. See also LASER THERAPY.

Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005

Laser

A device that concentrates electromagnetic radiation into a narrow beam and treats tissue quickly without heating surrounding areas.

Mentioned in: Arthroscopic Surgery

Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.

laser

An intense luminous source of coherent and monochromatic light. The term is an acronym for light amplification by stimulated emission of radiation. Lasers are used in the treatment of a variety of ocular conditions, especially of the cornea, the retina (e.g. detached retina, diabetic retinopathy), glaucoma and refractive errors. See cyclodiode; iridotomy; photorefractive keratectomy; LASEK; LASIK; scanning laser ophthalmoscope; photocoagulation; trabeculoplasty.
argon laser A laser with ionized argon gas as the active medium, which emits a blue-green light beam with a wavelength of 514 nm. It may be used to perform iridectomy, iridoplasty, iridotomy, photocoagulation or trabeculoplasty.
excimer laser A gas laser that emits pulses of light in the ultraviolet region (at 193 nm). All the energy is absorbed by the superficial layers (e.g. the corneal epithelium), which are then exploded away or ablated without any change to the underlying or adjacent tissue or material. See photorefractive keratectomy; LASEK; LASIK.
laser interferometry See clinical maxwellian view system.
laser iridotomy See iridotomy.
krypton laser A laser with krypton gas ionized by electric current as the active medium, which emits a light beam in the yellow-red region of the visible spectrum (521 nm, 568 nm or 647 nm). It may be used to perform photocoagulation or trabeculoplasty.
neodymium-yag laser  (Nd-Yag) A solid-state laser whose active medium is a crystal of yttrium, aluminium and garnet doped with neodymium ions. It emits an infrared light beam with a wavelength of 1064 nm. It is typically used with a slit-lamp and in conjunction with a helium-neon laser which produces a red beam of light (633 nm) to allow focusing. It may be used to perform capsulotomy, iridotomy or trabecular surgery. Yag is an acronym for yttrium-aluminium-garnet.
laser refraction See laser refraction.
laser refractive keratoplasty See photorefractive keratectomy.
laser trabeculoplasty See laser trabeculoplasty.

Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann

la·ser

(lā'zĕr)

A device that generates an intense, narrow beam of light created by bombarding an active medium (e.g., CO₂, Nd:YAG, argon), with energy in the form of high-voltage electricity, high-intensity light, or radio frequency waves. Lasers are used in microsurgery, for cauterization, excision, and for diagnostic purposes.

[acronym coined from light amplification by stimulated emission of radiation]

Medical Dictionary for the Dental Professions © Farlex 2012

Patient discussion about laser

Q. Should I have eye laser surgery? I am 17 and have been wearing glasses since I was a kid. I was thinking of having an eye laser surgery in order to fix my eyesight. What are the risks?

A. i had the surgery done almost a year and a half ago, i love it,the risk is minamal,do it,u won"t regret it,i now have 20/15 vision, and i was blind as a bat before,20/15 is over perfect vision!!!!!!!!!!!!

Q. Is there a laser vision correction operation that will correct both near and farsightedness? My optometrist said that typical laservision would require that I wear glasses for reading since it only corrects farsightedness. I'm leery of the technique of doing only one eye for distance and leaving the other "as is" for reading. I seem to recall a brief news report of some new laser vision technique that corrects both near- and farsightedness. Is that true or were they referring to the "one eye for closeup and one eye for distance" type of correction that I'm skeptical about? Thanks!!

A. my mother-in-law had that done about a yeara ago,for both near and far,they make them the oppisite,i had my near sightness fixed two years ago and i love it should of done it sooner.....

Q. I may have to undergo Laser Acupuncture next week. I am taking medicines for the heart attack I had last year and on my sons wish I am following acupuncture and after observation I may have to undergo Laser Acupuncture next week….I am afraid that this laser can lead to cancer …..And I also worried about the impact and effect of the medicine which I am taking…though my attack is in control will it be good to go for laser.?

A. Yes…This treatment is proved successful in many patients and you will have benefits too with this. They use laser to control the disease and it cannot cause cancer so don’t worry. Laser is being used in the treatment and it will not have any negative results in you. Just follow the medicines which you are currently taking and you will be guided with post surgery medications later.

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