Nonablative Cosmetic Laser: Q-switched lasers

Generic name: Q-switched lasers, including ruby 694 nm, alexandrite 755 nm, Nd:YAG lasers 532 and 1064 nm)

Brand(s): Q-switched lasers

Function / Purpose:
Hyperpigmentation, pigmentation irregularities, tattoos

Details:
Q-switched lasers are able to switch the beam on and off extremely quickly (in nanoseconds). This is very useful when trying to selectively target melanosomes (microscopic structures than produce skin pigment melanin) because melanosomes absorb and release energy very quickly, much quicker that other skin structures. Therefore, if laser is fired in extremely short bursts, it can selectively inactivate and/or permanently destroy melanosomes without affective other structures. As a result, q-switched lasers are a tool of choice for treating hyperpigmentation.

Q-switching has been used with lasers of different wavelengths. Shorter wavelength q-switched lasers, such as q-switched 532 nm Nd:YAG, are used mainly for hyperpigmentation located in the epidermis. These lasers should generally not be used in dark skinned individuals due to the risk of excessive loss of pigmentation. Longer wavelength q-switched lasers, such as such as q-switched 1064 nm Nd:YAG, largely bypass the epidermis and are used for deeper pigmentation disorders localized in the dermis (e.g. certain types of pigmentation under the eye). The intermediate wavelength q-switched lasers, such as 694 nm q-switched ruby, affects both epidermis and dermis and may be useful for thickly distributed pigmentation.

Unfortunately, q-switched lasers are quite expensive and are generally not used for indications unrelated to pigmentation problems or tattoos. As a result, relatively few facilities purchase this equipment.