How Does Laser Therapy Reduce Scars? A Comprehensive Overview

Basic Principles

Thermal Effect: When the laser irradiates the scar tissue, the tissue absorbs part of the laser energy and converts it into heat, causing the temperature of the scar tissue to rise. When the temperature reaches a certain threshold, the cellular structure of the scar tissue is destroyed, leading to the contraction, necrosis, and even shedding of the scar tissue. This can directly reduce the volume and height of the scar.

Photodynamic Action: Certain specific - wavelength lasers can excite the pigment granules in the scar tissue, causing them to absorb laser energy and undergo a photochemical reaction. This photochemical reaction destroys the pigment granules in the scar tissue, decomposing and eliminating them, thereby lightening the color of the scar and making it less noticeable.

Biostimulation: Laser irradiation can also stimulate the growth of new blood vessels around the scar tissue and promote the migration and proliferation of cells in the scar tissue. This helps accelerate the repair process of the scar tissue, promotes the regeneration of normal skin cells, and improves the texture and appearance of the scar.

Effects on Different Types of Scars

Hypertrophic and Keloid Scars: For hypertrophic and keloid scars, laser therapy aims to reduce excessive collagen production and flatten the raised scar tissue. Fractional laser therapy is commonly used, which delivers micro - beams of light to the skin, creating tiny wounds in the scar tissue. This triggers the body's natural healing response and promotes collagen remodeling. Over time, the scar tissue becomes smoother and less noticeable.

Atrophic Scars: For atrophic scars such as those caused by acne or chickenpox, laser therapy stimulates collagen production and promotes tissue regeneration. Fractional lasers can help fill in the indentations, and ablative lasers, which remove the outer layers of skin, can resurface the skin to reduce the appearance of atrophic scars. By encouraging new collagen growth, laser therapy makes the skin plumper from below, reducing the visibility of depressions.