Components of skin that absorb laser light.

TISSUE INTERACTION

How Does Laser Light Interact With Tissue?

It is only when the light is highly absorbed by a specific component of the skin that there will be a precise biological effect.  There are three components of the skin that absorb laser light. 

·         Melanin

·         Hemoglobin

·         Intra cellular or extra cellular water

How does laser light interact with tissue?  Laser List interacts with chromophores, the actual targets of lasers.  A chromophore is a chemical entity that absorbs a specific wavelength of the electromagnetic spectrum.  Chromophores are targets in the skin that are treated with a laser. 

Laser Light Interacts With Skin in Different Ways

Skin chromophores have colors which are distinct and intrinsic.  Melanin is the major chromophore found in the skin.  For the most part, melanin is stored in tiny sub cellular structures called melanasomes.  Lasers used to remove excessive or unwanted skin color are optimized for energy absorption by melanin.  The result of this process is the destruction of melanasomes or even of the cells that contain them.

Another major sin chromophore is Hemoglobin.  Hemoglobin is in the red blood cells that are abundant within blood vessels that are in the close proximity to the walls of the vessels.

Hemoglobin is the ideal chromophore to target if the goal is to damage or remove unwanted blood vessels, such as those that compose vascular birthmarks or spider veins.  The Hemoglobin absorbs the laser energy, which is immediately converted to heat.  In lasers like the PDL, a microscopic explosion literally blows apart the capillary.  Some lasers such as the krypton, has heat that damages the cells that line the blood vessel, resulting in coagulation of the blood.