|What’s in a laser?|
|What’s in a laser?|
A laser is an organized series of focused, high-energy light particles called photons. In fact, the word laser is an acronym for “light amplification by stimulated emission of radiation.” Although the lasers used in space labs and in other industrial applications are large and very powerful, the ones used by doctors are small and precise. Three types of lasers are used in medicine.
Carbon dioxide (CO2) laser. This laser removes thin layers from the skin’s surface. It is used primarily to remove skin cancers.
Neodymium: yttrium-aluminum-garnet (Nd: YAG) laser. Sometimes used to treat throat cancers, this laser can be carried through optical fibers to less accessible parts of the body.
Argon laser. This laser is used in dermatology and eye surgery because it can only pass through superficial layers. It’s also used with light-sensitive dyes in photodynamic therapy.
When lasers were first invented in the 1950s, scientists didn’t know what to do with them. Today, everything from computer printers to the entertainment industry incorporates laser technology.
But even more important, over the last 20 years, lasers have dramatically changed the way doctors operate. Laser surgery is replacing traditional procedures because it is often faster, more accurate and more economical. What’s more, recovery periods are shorter. In addition to refining tried-and-true procedures, lasers offer revolutionary new ways of treating certain conditions, like cancer.Widespread applications
The conditions that have benefited most from lasers are:
Glaucoma. This condition occurs when fluid and pressure build up inside the eye. During the corrective procedure, a laser is used to make 50 to 100 tiny tears inside the eye. The tears act as drainage holes that relieve pressure. Traditional surgery is riskier because the doctor must remove tissue from the eye.
Macular degeneration. Lasers can seal the leaky blood vessels responsible for this common eye disease that often leads to blindness.
Heart disease. For patients who are not getting enough blood to the heart, a laser procedure called transmyocardial revascularization (TMR) may be an option. In TMR, a laser is used to cut between 15 and 30 one-millimeter “tunnels” in the heart to enhance blood flow. This procedure is an alternative to angioplasty, bypass surgery and medication.
Sleep apnea. Patients who snore loudly because of blocked airways may have sleep apnea. The condition, which causes a person to stop breathing while he or she is asleep, is caused by relaxed throat and tongue muscles or excess skin that blocks air from escaping. Laser surgery can remove the excess tissue.
Birthmarks. Lasers are useful for removing skin pigmentations such as liver spots, moles and stretch marks. By painlessly “burning” off superficial skin layers, such marks can be lightened.In cancer treatment
Lasers can take aim at cancer cells, in an attempt to either ease symptoms or treat the cancer itself. If, for example, a tumor is blocking the windpipe, a laser can be used to shrink the tumor, allowing the patient to breathe more easily.
In laser-induced interstitial thermotherapy (LITT), an optical fiber is inserted into a tumor. Laser light from the tip of the fiber raises the temperature of the tumor, damaging the cancer cells.
For tumors that lie just below the skin’s surface, in the lining of internal organs or in hard-to-reach sites like the lungs, doctors can use a laser treatment called photodynamic therapy (PDT). In PDT, a special dye is injected into the body. The dye makes its way toward cancer cells. The dye is then hit with a laser, triggering a chemical reaction that kills cancer cells.