Until laser surgery was invented in 1963, someone with a growth, a cancer or a cataract, needed a major operation to have it removed. Now, laser beams can be used in ‘bloodless’ operations to remove growths and even repair tissues, without cutting, less painfully and more safely.
In laser surgery to remove a growth from the throat, for example, a small tube, or endoscope, is passed down the patient’s throat, under local anaesthetic. A laser beam is directed down the tube along an optical fibre and is focused on the growth. All laser surgery works on this principle of passing light down an optical fibre. The beam is a form of light which carries a great deal of energy. The energy is absorbed by the tissues of the growth, or the skin tissues to be removed, which become hot. By controlling the heat intensity, doctors can burn off — literally vaporise — unwanted cells.
In this way, laser beams are used to cut away cancers, vaporise the dyes in tattoos or get rid of birthmarks.
Another use of laser beams is to heat tissues sufficiently to `weld’ them together — to stop blood vessels bleeding, for example. The operation might be per-formed on a patient who is bleeding from a stomach ulcer.
The wavelength of the laser beam affects the way in which tissues respond to it. Lasers that use carbon dioxide produce beams of light which are absorbed by tissues at a depth of only 0.1mm. This means that they can be used to make fine cuts in tissue, as a sort of ‘laser scalpel’. Such precision cutting might be used when making incisions in the cornea of the eye to correct defects in sight, or in removing throat tumours.
Lasers using a metal-based chemical called neodymium produce light which is absorbed by a greater depth of tissue, making it useful to destroy cancers.
Those lasers that use the gas argon produce a distinctive blue-green light, which is absorbed by haemoglobin — the chemical in the blood that gives it its red colouring. Argon beams can therefore be used where haemoglobin levels are high,, in birthmarks.
A further benefit of laser beams is that they allow doctors to reach areas of the body previously hard to get at with a scalpel and to perform operations that were impossible before: to rid arteries of block. Ages of fatty deposits; to sew back detached retinas; to cut a hole through a cataract in a lens and so restore vision; and to cure cancer of the cervix.
Picture Credit : Google