Medical Laser Technology: Applications, Techniques, and Safety

Posted on Oct 19, 2025 in Biomedical Sciences

This document provides a detailed explanation of the technique, applications, indications, and contraindications of laser use in medicine and surgery.

Laser Technology in Medicine and Surgery

What Is a Laser?

LASER is an acronym that stands for: Light Amplification by Stimulated Emission of Radiation.

Lasers emit coherent, monochromatic, and collimated light, which can be precisely focused on tissues. The interaction of laser energy with biological tissues—ranging from cutting and vaporizing to coagulating and stimulating healing—forms the basis of its medical applications.

Technique of Laser Application

The technique of laser application is highly dependent on the type of laser, the target tissue, and the desired therapeutic effect.

1. Selection of Laser Type

Different types of lasers are selected based on their absorption characteristics in tissue:

• CO₂ Laser (10,600 nm): Highly absorbed by water; primarily used for cutting and vaporizing soft tissues.
• Nd:YAG Laser (1064 nm): Penetrates deeper; effective for coagulation and treating vascular lesions.
• Er:YAG Laser: Used in dermatology and dentistry for precise ablation with minimal thermal damage.
• Diode Laser: Common in soft tissue surgery and Low-Level Laser Therapy (LLLT).
• Excimer Laser: Utilized in ophthalmology (e.g., LASIK) and dermatology.
• Argon Laser: Used primarily in ophthalmology and dermatology for vascular lesions.

2. Laser Delivery System

The laser energy is delivered via:

• A handpiece or fiber-optic cable.
• Focusing mechanisms, such as lenses or mirrors.
• Adjustments to spot size and energy density.

3. Modes of Operation

• Continuous Wave (CW): Provides sustained energy for deeper penetration and coagulation.
• Pulsed Mode: Delivers energy in short bursts, allowing for precise cutting with minimal thermal damage.
• Super-pulsed Mode: Characterized by high peak power and very low overall thermal effects.

4. Application Techniques

• Contact Mode: The laser tip physically touches the tissue, often used for cutting.
• Non-contact Mode: The beam is applied from a distance, common in vaporization or scanning.
• Scanning Technique: The beam is moved over a large area to ensure uniform treatment.
• Point-and-shoot: Used for focused ablation or coagulation of small targets.

Applications of Lasers in Medicine

Lasers are utilized across numerous medical specialties:

A. Surgical Applications

Lasers are used for cutting, vaporizing, or coagulating tissues, offering benefits like reduced bleeding, high precision, and sterility.

Common Surgical Uses:

• ENT Surgery: Treatment of vocal cord nodules and nasal polyps.
• Neurosurgery: Tumor resection with minimized collateral damage.
• Gynecology: Endometriosis ablation and hysteroscopic procedures.
• Proctology: Treatment of hemorrhoids and fistulas.
• General Surgery: Removal of skin lesions and assistance in hernia repair.

B. Dermatology

• Tattoo and hair removal.
• Treatment of acne scars and keloids.
• Management of vascular lesions (e.g., port-wine stains, hemangiomas).
• Skin resurfacing and rejuvenation procedures.

C. Ophthalmology

• LASIK (Laser-Assisted In Situ Keratomileusis).
• PRK (Photorefractive Keratectomy).
• Retinal photocoagulation for conditions like diabetic retinopathy.
• YAG capsulotomy for posterior capsular opacification.

D. Dentistry

• Caries (decay) removal.
• Gingivectomy and periodontal surgery.
• Teeth whitening procedures.
• Root canal sterilization.
• Treating dental hypersensitivity.

E. Urology

• Prostate vaporization (e.g., HoLEP).
• Lithotripsy (laser fragmentation of urinary stones).
• Bladder tumor ablation.

F. Oncology

• Tumor debulking.
• Photodynamic Therapy (PDT).
• Palliation of airway obstructions caused by tumors.

G. Low-Level Laser Therapy (LLLT) / Cold Laser

LLLT uses low power density to stimulate biological processes without significant heating.

• Pain relief and management.
• Accelerated wound healing.
• Reduction of inflammation.
• Used extensively in physiotherapy and sports medicine.

Indications for Laser Use

General Indications

• Requirement for precise tissue removal or ablation.
• Need for effective hemostasis during surgical procedures.
• Sterile, non-contact cutting capability.
• Procedures requiring minimally invasive techniques.
• Cosmetology (e.g., skin tightening, scar removal).
• Refractive eye surgery.
• Treatment of chronic non-healing wounds.

Specialty-Specific Indications

Contraindications of Laser Therapy

A. Absolute Contraindications

• Pregnancy: Especially for cosmetic procedures or when the indication is unclear.
• Malignant Tumors: If the laser treatment area overlaps with the tumor (unless used specifically for palliation or PDT).
• Active Infections: In the immediate treatment area.
• Photosensitive Disorders: Conditions exacerbated by light exposure.
• Patients with Pacemakers: Certain high-power laser therapies may interfere with device function.

B. Relative Contraindications

• Uncontrolled Diabetes Mellitus: Due to potential poor wound healing.
• History of Keloids or Poor Wound Healing.
• Recent Sun Exposure or Tanning: A major concern for dermatologic lasers, increasing burn risk.
• Epilepsy: Due to the potential trigger effect of flashing light.
• Use of Photosensitizing Medications: (e.g., isotretinoin, tetracyclines).

Precautions and Safety Measures

Strict adherence to safety protocols is mandatory when operating medical lasers:

• Mandatory eye protection (specific wavelengths) for both patient and staff.
• Use of laser-safe instruments and non-reflective surfaces.
• Posting of warning signs and ensuring restricted access to the laser operating area.
• Use of a smoke evacuator system to safely remove the laser plume (surgical smoke).
• Operation and maintenance must be performed by trained and certified personnel.

Conclusion

Laser technology has revolutionized modern medicine, offering precision, reduced recovery time, and a wide range of therapeutic options. However, optimal outcomes depend on proper case selection, thorough knowledge of indications and contraindications, and strict adherence to safety protocols.