Novel picosecond handpieces for the treatment of pigmentation

April 21st, 2021
Pigmentary disorders are common with several treatment modalities available ranging from topical therapy to chemical peels and lasers. The advent of ultrashort pulsed picosecond lasers (PSL) transformed the way tattoos and benign pigmented lesions are treated. Unlike long-pulsed lasers (milli to microsecond domain) and Q-switched lasers (nano second domain), the PSL deliver very short pulse durations in one trillionth of a second ( range) giving a predominantly photomechanical effect rather than a photothermal one. This in turn has increased safety on the tissue with less complications, particularly in the higher skin types1. Several PSL exist with different pulse durations and wavelengths. In this article I will explain the way I use two new handpieces of the Candela PSL called Picoway™. The Picoway™ system is a PSL with a total of 6 handpieces spanning across 4 wavelengths (532, 730, 785 and 1064 nm). The non-fractional handpieces are called zoom (532 and 1064nm) or full beam (730 an 785nm), the fractional handpieces called Resolve (532 and 1064nm), and the newer Resolve Fusion handpiece (532nm) merges in one pass one the benefits of fractional and full beam treatments.

There are 2 new handpieces for which I was the first doctor in Europe to work on; namely the unique 730 nm titanium sapphire generated wavelength and the 532 Resolve Fusion fractional handpiece. Below are 2 cases detailing how I integrate these handpieces in the treatment of pigmentation.

Cases report:
In the first case I have a 53-year old woman with skin type 3 and photodamage with benign lentigines and freckles on the face. The novel 730 nm handpiece was used first as a spot treatment for the individual benign lesions. The spot size of 4 mm was used with a fluence of around 1 J/cm2 adjusted down to the use of 2 mm between 2.6 and 3 J/cm2 depending on the achievement of the clinical endpoint which is light whitening of the lesions preserving the surrounding tissue. In the light-coloured lesions an additional pass was performed. Subsequently, the 532 nm Resolve Fusion handpiece was used with a fluence of 0.5 mJ in 2 passes over the entire face with erythema as a clinical endpoint. Post care moisturizer and sunblock were advised. Marked improvement in the pigmentation was noted during her second visit in 4 weeks follow-up (figure 1).

In the second case a 45-year old Chinese woman with skin type 4 presented with discrete lentigines on the zygomatic area of her right cheek which she was keen to get rid of. The 730 nm handpiece was used with both the 2 and 3 mm spot with fluences ranging between 1.6 to 2.6 J/cm2 until the desired endpoint of mild whitening was achieved. A potent topical corticosteroid cream was prescribed to use twice daily for 3 days together with meticulous sun protection. Clearance of the lesions was achieved with no adverse effects (figure 2).

The treatment of benign pigmented lesion with lasers require the selection of the right wavelength and parameters to ensure a high clinical clearance with low complications, particularly in higher skin types. The novel 730 nm wavelength is unique in that it is highly absorbed by melanin (more than both 755 and 785 nm) with very low haemoglobin (less than both 755 and 785 nm) absorption. It also has the shortest pulse duration of any PSL wavelength available at 250 ps2. This is important as it is shorter than the stress relaxation time of the melanosomes leading to a predominantly photoacoustic method of pigment clearance with little collateral damage.

The 532 nm Resolve Fusion provides an array of microbeams which combines a high fluence central beam with a low fluence peripheral rim allowing for greater coverage per pass with less impact in the central beam leading to less side-effects such as petechiae in higher skin types3. This fractionated beam gives a distinct microscopic injury termed light-induced optical breakdown with cell-signalling for rejuvenation and a mechanical destruction of melanosomes leading to enhanced clearance of diffuse pigmentation with little downtime.

1. Wu DC, Goldman MP, Wat H, Chan HHL. A Systematic Review of Picosecond Laser in Dermatology: Evidence and Recommendations. Lasers Surg Med. 2020 Apr 13. doi: 10.1002/lsm.23244. Epub ahead of print. PMID: 32282094.
2. Lipp MB, Angra K, Wu DC. Safety and Efficacy of a Novel 730?nm Picosecond Titanium Sapphire Laser for the Treatment of Benign Pigmented Lesions. Lasers Surg Med. 2020 Sep 1. doi: 10.1002/lsm.23314. Epub ahead of print. PMID: 32869883.
3. Miyata N. Picoway clinical insights: innovative picosecond laser with 4 wavelengths. Candela corporate white paper 2020.