The alexandrite laser has a wavelength of 755 nm, a pulse duration of 50-100 ns, a spot size of 2-4 mm and is delivered by a fiberoptic arm. Fiberoptic delivery allows a more even beam profile with fewer hot spots.
The wavelength of the Q-switched alexandrite laser (QSAL) is similar enough to that of the QSRL to obtain comparable results for the treatment of epidermal and dermal pigmented lesions, perhaps with the added advantage of a slightly deeper penetration. Similar to the QSRL, this laser is effective at removing black, blue, and most green tattoo inks, and less proficient at removing red or orange inks.
Depending on the spot size, a starting flu-ence of 5-6 J/cm2 is usually employed. Immediately after treatment, gray-whitening of the skin occurs, followed by erythema and edema. There is a lower risk of tissue splatter because of the longer pulse duration and the more even beam profile. There is also a lower risk of transient hypopigmentation because of slightly less QSAL melanin absorption as compared to the QSRL.
used in freehand mode, reproducibility is lacking and the thermal damage is somewhat unpredictable. The risk of scarring and pigmentary changes is therefore significant in the hands of inexperienced operators. In general, these CW lasers, when used by skilled operators, are effective in the treatment of epidermal pigmented lesions.
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