Assessment of the Efficacy of Nonablative Long-Pulsed 1064-nm Nd:YAG Laser Treatment of Wrinkles Compared at 2, 4, and 6 Months

Abstract

Rhytides represent an aesthetic problem for a large percentage of the population. Many methods, both noninvasive and invasive, have been used for the treatment of wrinkles. Recently, the long-pulsed 1064-nm Nd:YAG laser has been shown to enhance dermal collagen synthesis without damaging the epidermis. The purpose of this preliminary study is to evaluate the use of the long-pulsed Nd:YAG laser in the nonablative treatment of periocular and perioral wrinkles. Ten patients with facial wrinkles were treated with the long-pulsed 1064-nm Nd:YAG laser, at a spot size of 5 mm in diameter, energy density of 13 J/cm2, exposure time per pulse of 300 microseconds, and a repetition rate of 7 Hz. All patients had a total of three treatments, once every 2 weeks. Subjective (patient satisfaction index [SI]) and objective (both physician- and computer program-based clinical index [CI]) assessments were performed before the first and third treatment sessions, and at 2, 4, and 6 months after the last treatment. At 6 months after the final treatment session, the patients' subjective SI was maintained at 40%, and had peaked at 50% 2 months after the final session. Physician assessment showed a CI of 40% at the 6-month assessment point and the computer program showed a 50% CI. The greatest level of effect with long-pulsed Nd:YAG laser nonablative skin rejuvenation for facial wrinkles was seen 2 months after the final treatment. Effects were still visible at the 6-month period, but showed a tendency to decrease. Maintenance treatments are required to achieve good patient satisfaction.

Retrospective analysis of non‐ablative scar treatment in dark skin types using the sub‐millisecond Nd:YAG 1,064 nm Laser

“…The first mechanism involves discrete cellular damage caused by direct absorption in hemoglobin, melanin, and water during each pulse and bulk heating from cumulative pulsing in a region. As a result, damage created through direct absorption and through sustained time at elevated temperature initiates a healing response, prompting collagen stimulation [21,22].…”

Laser induced collagen remodeling: A comparative study in vivo on mouse model

“…Several studies have confirmed the findings that PDL treatment of sun-damaged skin can lead to improvements in wrinkles with histological evidence [10][11][12][13][14][15]. Long pulsed 1,064-nm Nd:YAG laser with its low scattering coefficient and weak absorption by water and melanin has also been shown to improve the appearance of coarse wrinkles and fine lines and to reduce skin laxity [16][17][18][19][20]. Rapid sequences of long 1,064-nm pulses (0.3 ms) enable a large area to be covered quickly by multiple passes, causing diffused general heating of the upper dermis and thus stimulating a wound healing response and collagen remodeling.…”

“…The large scattering coefficient of the 1,320-nm Nd:YAG laser causes the thermal energy to disperse laterally within the dermis, inducing a large volume of dermal injury relative to the beam size [23]. For the long-pulsed 1,064-nm laser, since the main target is protein with water as a secondary target, the heating effect in the target tissue absorbing the 1,064-nm beam is non-specific [20]. In addition, because of the scattering effect of tissue at this wavelength, the area of the highest photon density, and thus the photo-thermal effect, is not at the surface of the tissue, but some 1-2 mm below the surface [20].…”

“…For the long-pulsed 1,064-nm laser, since the main target is protein with water as a secondary target, the heating effect in the target tissue absorbing the 1,064-nm beam is non-specific [20]. In addition, because of the scattering effect of tissue at this wavelength, the area of the highest photon density, and thus the photo-thermal effect, is not at the surface of the tissue, but some 1-2 mm below the surface [20]. The Q-switched 1,064-nm Nd:YAG laser is characterized by very short pulse width, which produces the dermal damage mainly by the photo-mechanical effect; moreover, the Q-switched laser has less water absorption and lower scattering, which results in a relatively deeper dermal wound [3].…”

Cutaneous photoaging treated with a combined 595/1064 nm laser

“…In addition, studies have documented new collagen formation following exposure to this wavelength, resulting in the clinical improvement in rhytids and photorejuvenation (4,5).…”