1001uses for laser

Imagine a narrow, one-way, coherent, moving, amplified beam of light, fired by excited atoms, powerful enough to slice through steel, carry television transmissions and detect 40 year old fingerprints. In 1917, Einstein speculated that under certain conditions atoms could absorb light and be stimulated to shed their borrowed energy. Charles Townes conceived of the laser (light amplification by stimulated radiation) in 1951. In 1960, Theodore Maiman invested the glare of a flash lamp in a rod of synthetic ruby, creating the first human-made laser. The laser involves exciting atoms and passing them through a medium such as crystal, gas, or liquid. As the cascade of photon energy sweeps through the medium, bouncing off mirrors, it is reflected back and forth, gains energy, and emerges as a high wattage beam of light. Little did the inventors realize how the laser would come to affect nearly every product, service, and profession. Lasers are used by professions as diverse as agronomy and photography to manufacturing and meteorology.

However, some of the most revolutionary advancements in laser technology have been through their use in medicine. Lasers can currently be found in the fields of dermatology, gynecology, cardiology, ontolaryncology, urology, dentistry, back care, oncology, and opthalmology. As a surgical tool the laser is capable of three functions. When focused on a point it can cut deeply, cauterizing as it cuts, reducing the surgical trauma caused by a knife. It can scan tissue, vaporizing the surface which it scans. Or, through optical fibers, it can permit a surgeon to see inside the body.

Skin Deep

Laser's earliest medical applications were in the field of dermatology. Impressively, in the treatment of skin problems, the laser causes little discomfort, carries no risk of infection, and produces no scarring. In 1986, the FDA approved dye lasers for use in the treatment of birthmarks. Firing a laser at a port-wine stain causes the dense network of blood vessels to close&emdash;photocoagulation&emdash;thereby reducing redness. Dramatic results have been seen in the treatment of infants.

In addition, lasers effectively bleach the dyes in unwanted tatoos, fade the pigments in age spots and moles, can reduce wrinkles, and help heal skin ulcer wounds. Dermatologists feel lasers may eventually be valuable in the treatment of varicose veins and skin cancer.

For Women Only

Lasers have also been used extensively in the field of gynecology. Again, the laser is faster, less invasive, reduces infection risks, and allows for a quicker recovery. Lasers have been used to treat ectopic pregnancies, dysmenorrhea, ovarian cysts, and endometriosis by vaporizing diseased or excess tissue. Lasers have also been used to perform hysterectomies, and to reconstruct damaged or blocked Fallopian tubes, allowing infertile women to conceive.

Additionally, lasers have aided in the screening and early detection of cervical cancer, which is nearly always curable in its early stages. Fluorescent-dyed tissue samples, when struck by laser light reveals quantities of normal and abnormal cells, leading specialists to diagnose cancer's presence and stage.

Have a Heart

In the field of cardiology, lasers have not perfomed as well as hoped. Lasers were hailed as an alternative to angioplasty. Doctors hoped that lasers could be threaded into arteries with a catheter to blast away calcium plaque build-up. In fact, some patients were operated on successfully. However, the procedure risks creating dangerous blood clots or puncturing an artery. Furthermore, catheters proved too stiff to pass through the body's convoluted blood vessels. Further research may still find the laser valuable in heart surgery.

Ear, Nose and Throat

Ontolaryncology has seen several practical advantages to the laser rather than a scalpel. In larynx surgery, any damage to the voice box can severely impair speech. The laser is able to vaporize lesions without additional damage to the larynx. Lasers have also been successful in treating snoring by trimming away part of a persons' uvula. Lasers have restored some people's hearing by effectively vaporizing defective, hardened or locked stape bones in the ear. And lasers have a 90% success rate in treating chronic rhinitis&emdash;persistent congestion and running nose. Applied to the surface of the swelled tissues in the nose, the laser creates scar tissue that acts to prevent future swelling. Lasers have also been used to remove nasal polyps and tumors, and to treat chronic nosebleeds by sealing off blood vessels.

For Men Only

While the laser has not gained widespread acceptance in urology, it appears that they soon will. Lasers have been used for years to treat early-stage bladder cancer. Advancements have also been in using lasers to treat enlargement of the prostate. A Nd-YAG laser is used to remove tissue. Over 100,000 laser prostate operations are done each year. Within five years, over 60% of the prostate surgery will be done using lasers. Doctors feel that lasers may also be valuable in reversing vasectomies by welding the gap that is cut during a vasectomy.

Open Your Mouth

While not widely used, lasers may make visits to the dentist more pleasant for patients. Experimental uses hold hope for the future. Lasers have been used to clean out root canals, in surgery for TMJ jaw disease, in the vaporizing of plaque and the cleaning of teeth, in melting dental filling material, and in 3-dimensional imaging to record minute changes by orthodontists checking for misaligned teeth or the effects of braces upon teeth.

My Aching Back

Patients suffering from herniated disks, and unable to recover using physical therapy, can now be treated with lasers. Over 500,000 Americans undergo back surgery each year. Lasers can be used to vaporize tissue in a disk, creating a vacuum. This causes the disk to shrink away from the pressed nerve, relieving pain. Such surgery eliminates the need for cutting, scarring, hospitalization, postoperative instability, immobility, and the need for general anesthesia. The cost is only $6,000&emdash;one third of traditional disk surgery.

Cancer Fighter

In addition to the laser's use in detecting cervical cancer, lasers have been used as probes, aiding in the imaging and detection of tumors. A new laser probe allows surgeons to see layers of tissue beneath and around the scalpel without having to make a wide, destructive incision. By inserting the probe into an incision as small as 3 mm, surgeons are able to see instant pictures of a patient's anatomy as the surgeon is operating, resulting in direct, immediate evidence of his or her progress in vaporizing a tumor.

Lasers also hold a promising role in the treatment of certain types of cancer. In experiments, HPD (hematoporhyrin derivative), a laser sensitive dye, is injected into the body and absorbed by all the body's cells. The HPD remains in malignant cells. Activated by a laser, the HPD can be used to dissolve the malignant cells, eliminating the need for radiation treatment and chemotherapy.

The Eyes Have It

No field has seen greater accomplishments with lasers as opthalmology. The advantage in this field is that the laser beam can enter the eye without injuring it. Lasers have been successfully used for photocoagulation to seal leaking blood vessels, repair retinal hemorrhages, or weld detached retinas. Through iridectomy, lasers can relieve the fluid build up of glaucoma. In photodisruption, lasers remove tissue, allowing the insertion of an artificial lens behind the iris. With photoradiation and photovaporization, the laser is used as a bloodless scalpel to destroy eye tumors. In cases of diabetic retinopathy (degeneration of the retina), lasers have prevented blindness by destroying excess blood vessels on the retina's surface. Lasers can also correct scars and remove calcium deposits on the eye.

Just last year, the FDA approved the use of Summit Technology's blue-light, diode excimer laser for the treatment of nearsightedness, which affects over 60 million Americans. During the 20 minute bloodless procedure, a cold laser is fired at the cornea, shaving and reshaping it to provide 20:40 vision. Called photorefractive keratectomy (PRK), the procedure has been done on over 250,000 patients so far and will soon be commercially available for $1,500 per eye. Doctors hope that PRK may lead to similar procedures to replace corneal transplant surgery, and to correct astigmatism and congenital farsightedness.

These procedures represent just the beginning. Ongoing research shows additional medical uses for the laser, including laser accupuncture, laser induced fluorescence to detect chemicals in blood, endoscopic gastrointestinal treatment, the treatment of the affected limbs of cerebral palsy patients, and a cold laser that reduces the swelling and onset of carpal tunnel.

Lasers have come a long way since their creation in the 1960s. They are a prime example of how the movement of an idea can truly change the world. While they are not a medical cure-all, there have been major medical advancements because of them. Hurdles remain. Many procedures await FDA approval. Some doctors are reluctant to use new, unfamiliar tools. And, the equipment cost remains high. For many patients, however, lasers are a promising tool that offers much hope. According to a Liquid Vision developer, "Laser advancements in the 1990's will rival computer advancements of the 1980's."