Laser Therapy

Application of lasers in medical, diagnostic and therapeutic procedures are wide-ranging. Following are a few uses of lasers:

• Medical interventions with laser therapies
  • Kidney stone or gallstone treatment with lithotripsy: Lithotripsy is the use of energy to break hardened masses in the body. While there are other methods of intracorporeal lithotripsy, laser lithotripsy is the preferred method.
  • Angioplasty: Using laser energy and its “cutting” properties, coronary arteries are freed of the atherosclerotic plaque buildup to prevent further blocking of the artery lumen, reduction of blood and oxygen flow to the heart and a possible heart attack (myocardial infarction).
  • Drug-Resistant Epilepsy (DRE): Earlier, in patients with focal drug-resistant epilepsy, the surgical removal of the epileptogenic (seizure-inducing) zone of the brain was attempted to achieve a permanent cure. Today, magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) has emerged as a less invasive option for laser ablation rather than resection of the problematic brain area.
• Laser therapies in cancer medicine: Laser therapy is used in the treatment of certain cancers alongside chemotherapy, surgery, and/or radiation therapy. Overall, laser therapies in cancer can have the following roles and goals:
  • Shrink or destroy tumours, polyps or other precancerous growths
  • Relieve symptoms of cancer
  • Resecting cancerous tumours
  • Seal tissue after resection of the tumour
  • Laser therapy is useful in the treatment of the following cancers in early stages: Cervical cancer, Penile cancer, Vaginal cancer, Vulvar cancer, Non-small cell lung cancer, Basal cell skin cancer, Melanoma skin cancer
• Lasers in surgical therapies: Laser devices are used to assist in surgeries and can typically perform the following functions:
  • Cutting through various tissues for resection via the cautery function
  • Sealing nerve endings to reduce pain after surgery by a cauterising function
  • Sealing blood vessels to help prevent blood loss by a cauterising action 
  • Sealing lymph vessels to reduce swelling and limit the spread of tumor cells by a cauterising function 
• Ophthalmology: Various kinds of lasers, designed specially for use in the eye, are available to treat different eye problems. 
  • LASIK surgery (Laser-Assisted In-Situ Keratomileusis): A thin layer of the cornea is removed using an ultraviolet excimer laser, thereby reshaping the surface and correcting refractive error of the eyeball and improving vision. 
  • Trabeculoplasty for treatment of glaucoma: A simple procedure that uses a laser to coagulate and help drain the fluid buildup within the eye in glaucoma. (Read more: Glaucoma surgery)
  • Cataract surgery: A special femtosecond laser makes a small and precise incision in the cornea through which the cataract is removed and the new IOL (intraocular lens) is placed.
• Cosmetic dermatological laser therapies:
  • Laser hair removal for undesired hair (such as body hair, facial hair, etc.)
  • Removal of warts, moles, birthmarks, sun spots and other undesirable but medically harmless growths on the skin.
  • Aesthetic medicine for anti-aging concerns to lessen the appearance of wrinkles and age spots
  • To lessen the appearance of blemishes and scars
  • Laser treatment for hair loss resulting from alopecia or aging 
  • Laser tattoo removal

Specialised laser modalities and methods are used in the treatment and diagnosis of many different conditions. Following are a few common approaches using lasers:

• Photobiomodulation (PBM) therapy: Previously known as low-level laser therapy (LLLT) and also known as cold laser therapy, this is a type of laser therapy that involves the application of red and near infra-red light (wavelength of 600 to 1000 nanometers) over injuries or lesions to improve wound and soft tissue healing, reduce inflammation and give relief for both acute and chronic pain. The uses of photobiomodulation therapy are extensive and, to name a few, include: 
  • Cancer treatment 
  • Dermatological, like for alopecia and skin rejuvenation
  • Ophthalmological, like for age-related macular degeneration (ARMD), diabetic retinopathy 
  • Arthritis and tendinitis 
  • In physiotherapy, like for muscle fatigue, athletic performance, body pain and wound healing 
  • Neurodegenerative conditions, like Alzheimer’s, Parkinson’s, multiple sclerosis, post-stroke, etc. 
  • Dental like oral mucositis, post tooth extraction pain
• Photodynamic therapy (PDT): A photosensitising agent (drug) is introduced into the patient’s bloodstream (usually intravenously) and this drug is selectively uptaken by cancer cells more than healthy tissue. Afterwards, the patient is subjected to an argon laser light that activates the photosensitive agent, causing a chemical reaction to occur within the cancer cells that kills them. The timing of photodynamic therapy is such that the photosensitising agent is allowed to accumulate in maximal concentrations in the cancer cells. Many cancers and precancerous conditions of the bile ducts, bladder, lungs, pancreas, brain and prostate are treated this way. Photodynamic therapy is also used for the treatment of dermatological conditions and plays a notable role in the management of psoriasis.
• Intravenous laser blood irritation (ILBI): A low-level laser light is introduced into a peripheral vein in the patient and light of a specific wavelength and frequency is emitted. This therapy operates on the assumption that the irradiation delivered via the vein will spread throughout the body by the systemic circulation. While intravenous laser blood irradiation (ILBI) has been used for the treatment of rheumatoid arthritis and the prevention of vascular diseases previously, many more applications are being researched presently. Current research on the use of ILBI therapy to regulate the metabolic profile of diabetes mellitus patients has shown promise.

There are not many preexisting conditions or circumstances that would make the use of lasers in diagnosis and therapy unwise. However, the following are some relative contraindications (which may be possible to overcome with special steps in some cases) of laser treatments:

• Pacemakers: The presence of a pacemaker is not always a contraindication for laser therapy as the device itself is enclosed in a metallic encasing. However, when laser therapy is combined with electrical or magnetic impulses in certain treatments, the presence of a pacemaker would be a contraindication. (Read more: Pacemaker Surgery)
• Pregnancy: It was earlier believed that pregnancy should warrant the avoidance of laser therapies. Research now suggests that cutaneous (dermatological) laser therapies during pregnancy do not pose a risk to the mother or the foetus. However, due to a lack of sufficient data on other laser treatments, many doctors choose to avoid their use during pregnancy.
• Thyroid disorders: While laser ablation therapy is useful in the treatment of both benign and malignant thyroid tumours, the gland itself is also susceptible to absorbing energy (such as radiation or laser energy). Therefore, precautions must be taken to protect the thyroid gland while instituting laser treatments. Due to the lack of documented clinical evidence, it is better to err on the side of caution with respect to the thyroid gland. 
• Epileptic seizures: Similarly, while laser ablation of the epilepsy-inducing zone of the brain is a useful last-line treatment for drug-resistant epilepsy, certain light frequencies are also known to induce seizures in epileptics. Caution must be observed during the laser therapy.

Some complications are common to all kinds of laser therapies. These typically include, but are not limited to:

• Burns
• Scarring
• Dyspigmentation
• Ocular injury
• Infection

Besides the general complications arising from laser therapy procedures, some complications specific to different treatments can also arise.

• Complications with dermatological laser therapies: Some risk exists for development of complications after the application of lasers for dermatological therapy.
  • Bleeding
  • Infection
  • Pain
  • Scarring
  • Changes in skin color
  • Skin pigmentation
  • Some laser dermatological cosmetic procedures may not have a permanent effect and repeated sessions may be necessary
• Complications of photodynamic therapy for esophageal cancer: The following complications are known to arise after laser photodynamic therapy (PDT) to the oesophagus:
  • Hiccups
  • Difficulty swallowing
  • Nausea and vomiting
  • Dehydration
  • Fever
  • Narrowing or scarring of the esophagus
  • Fluid buildup around the lungs
• Complications of photodynamic therapy for small cell lung cancer: Photodynamic therapy use in small cell lung cancer can, at times, cause complications like: 
  • Shortness of breath
  • Fever
  • Lung Infections like pneumonia or bronchitis
  • Coughing up blood