The use of lasers is a groundbreaking invention using fundamental physics concepts. Due to their versatility, lasers are used in medicine, metal-cutting machines, CD players, etc. According to the Lawrence Livermore National Laboratory, LASER is an acronym that stands for Light Amplification by Stimulated Emission of Radiation. Simply put, a laser is a device that emits a beam of light. They can be made from visible light, X-rays, ultraviolet rays, or infrared light. Click on this video to see how lasers work.
Lasers are regularly used in medicine for treatment purposes, especially for surgeries such as cosmetic surgery, refractive eye surgery, dental procedures, or general surgery. Azo materials says that Lasers allow the patient to decrease postoperative discomfort, reduce the chance of wound infection and reduce the wound size. It also increases the precision with the use of flexible optics to allow surgery in deeper parts of the body without huge incisions. In addition, doctors can use lasers instead of a scalpel to cut through tissue as the thermal energy seals off blood vessels and thus limits bleeding or swelling Since it has minimal cutting, the operating and healing time is much shorter.
Laser Eye Surgery (LASIK)
Laser eye surgery is performed to correct refractive eye problems by changing the focal point where light reaches one’s eye. Laser-assisted in situ keratomileusis (LASIK) eye surgery is one of the most common types to reduce the dependency on glasses or contact lenses. We can see in a video by Nucleus Medical Media, and the first step is to separate a thin layer from the front of the retina with a flat-wide blade or a femtosecond laser. Next, an excimer laser, a form of ultraviolet laser, reshapes the cornea by using a combination of noble gas and reactive gas that vaporizes the corneal tissue. This procedure is called photoablation. The flap is then put back over the cornea and left to heal for a few hours. Since the cornea binds quickly, it does not require stitches.
To understand how refractive error is treated, it is important to know how refraction works in the eye. Sightsavers states that the cornea and lens (clear disc-like structure) work together to focus on the light ways that pass through the eyes; the lens is adjusted by the ciliary muscle to change shape and focal length to help focus objects at different positions. A healthy and normal eye is able to converge light properly by changing the lens shape for clear visibility of both near and far objects. However, certain conditions result in blurred vision.
Myopia (nearsightedness)
According to the Mayo Clinic, it is a refractive error that the cornea is excessively curved which creates greater index refraction. This causes the image to form in front of the retina and results in a blurred distant vision. In the laser-eye treatment, it is used to remove certain amounts of the cornea to flatten it. This enables images to focus on the retina.
Hypermetropia (Farsightedness)
It is a condition that the cornea is not curved enough and thus the light focuses behind the retina. This creates blurry near vision. Lasers are used on the outer edge of the cornea to remove small amounts of the cornea. This increases the refractive index and allows images to focus on the retina instead of the back.
Astigmatism
When the cornea curves or flattens unevenly with two different curvatures, light enters the eye without focusing at a single point, causing distorted images. Lasers are used to remove small amounts of the cornea to make it more even.
Lithotripsy Surgery
Laser lithotripsy is a procedure to use a laser to break kidney stones into very small pieces to be removed by the surgeon or passed out of the body in the urine. Alberta health says that Kidney stones can be trapped in the urinary tract, including the kidney and the ureter. If the stone is stuck, it can block the flow of urine and build up toxins which can be fatal. When it is infected, it is also very painful.
Image is Courtesy of Nature.com
Winchester Hospital states that the ureteroscope is an instrument that is a long and thin hollow tube. It is used for the doctors to view the urinary tract. Once the doctor spots the stone, the fibre is sent through the ureteroscope to the stone and creates a laser beam to fracture the stone. In some cases, a temporary stent may be placed in the ureter to keep it open, improve urine flow and let the stone pieces pass easily.
Cancer treatment
The Canadian Cancer Society says that Laser surgery can be used to shrink or destroy abnormal tissue or small tumours on or near the surface of the skin. For example, they can treat the early stages of some cancers in the cervix, vagina, or penis. They can also be used to relieve certain cancer symptoms such as bleeding or shortness of breath. For instance, the tumour can block a patient’s trachea or esophagus. Unfortunately, large tumours cannot be removed.
There are three major types of lasers used. Carbon dioxide and argon laser remove the thin layers from the surface of the skin without going to deeper layers, such as skin cancer. Carbon dioxide cancer can be used to treat pre-cancer or early cancer stages, while argon lasers are used for photodynamic therapy (PTD), which uses light-sensitive drugs to kill cancer cells. On the other hand, Nd: YAG (Neodymium: Yttrium-Aluminum-Garnet) lasers can go much deeper into tissue. They travel through fibre optic cables in an endoscope into specific areas of the body, such as the esophagus and colon. Most often, lasers are often used with other cancer treatments cush as chemotherapy.
Laser Skin Resurfacing
Laser skin resurfacing is a type of cosmetic surgery used to reduce facial wrinkles, scars, and blemishes. The American Society of Plastic Surgeons says the surgeon uses the lasers to send short and concentrated beams of light to the skin to remove or vaporize damaged skin. It removes the outer layer of skin called the epidermis and heats the underlying skin called the dermis to stimulate the growth of new collagen fibres. The new skin forms during healing are much smoother and firmer. Ultimately, it helps your skin look younger and healthier.
Environmental impact
Although lasers are beneficial in many fields, they do have some disadvantages. According to LASERS, some lasers are work at very high temperatures, which require a lot of water as a coolant. This poses a negative impact on the environment as large amounts of water are wasted yearly.
Conclusion
Overall, this innovative idea of using lasers in surgical treatments is a frequent and prevalent practice. It maximizes the precision, convenience ,and effectiveness, which leads to thousands of more successful surgeries, ultimately benefiting physicians and patients. Furthermore, as laser technology is constantly improving, it is undeniable that its application in medicine is holistically beneficial to society.
Article Author: Michelle Lam
Article Editors: Edie Whittington, Stephanie Sahadeo