What is the primary determinant for predicting tissue interaction with laser light?

The primary determinant for predicting how tissue interacts with laser light is absorption. This is because different tissues have varying levels of chromophores (molecules that absorb light) which determine how effectively they absorb specific wavelengths of laser light.

When laser light strikes tissue, the extent to which the light is absorbed directly influences the effects produced, such as heating, vaporization, or coagulation. The absorption characteristics of the tissue at specific wavelengths dictate the outcome of the laser treatment. For example, certain wavelengths are better absorbed by the pigments in blood (hemoglobin) or the water content in tissues, which can lead to different therapeutic or destructive effects depending on the target tissue.

While factors like wavelength, energy, and intensity are important as well, they all influence the interaction through the mechanism of absorption. The wavelength determines which chromophores will interact, energy relates to the total amount of light delivered, and intensity signifies the power of the laser beam. However, without considering absorption, predictions about the effectiveness of laser treatments would be incomplete, as absorption is the fundamental property that drives tissue interaction with laser light.