Why do Nd:YAG lasers typically have greater potential for tissue damage than erbium lasers?

Nd:YAG lasers have greater potential for tissue damage primarily due to their ability to penetrate deeper into tissues and their higher absorption by pigments. The Nd:YAG laser operates at a wavelength of 1064 nm, which is less readily absorbed by water compared to the shorter wavelengths used by erbium lasers. This characteristic allows Nd:YAG lasers to reach deeper layers of the skin and other tissues, where they can affect structures such as blood vessels and pigment-containing cells.

The deeper penetration of Nd:YAG means that more energy can be delivered to tissues that are not just superficially located, increasing the risk of thermal damage. Additionally, because these lasers can target pigments within tissues, they can effectively treat deeper skin concerns, but this capability also raises the potential for unintended damage if not carefully applied. In contrast, erbium lasers, which operate at a wavelength around 2940 nm, have higher absorption by water, resulting in a more superficial effect and a lower risk of deeper tissue damage.

This understanding of the mechanisms behind the functioning of both laser types highlights the importance of selecting the appropriate laser based on the intended treatment depth and the specific characteristics of the tissue being treated.