Investigating the efficacy of a fractionated 1927 nm laser for diffuse dyspigmentation and actinic changes

Facial actinic irregularities are frequent targets for noninvasive, energy-based treatment. These irregularities are multifactorial and driven by both intrinsic factors such as aging, genetics, and hormone exposure, and extrinsic factors, such as UV exposure. Clinically, this photodamage manifests as dyschromic skin disorders like melasma and actinic features such as solar lentigines. Fractionated 1927 nm (f1927 nm) nonablative lasers are suitable for targeting epidermal lesions and have been shown to be effective in resurfacing photoaged skin as well as addressing pigmented lesions without exacerbation. The purpose of this study was to quantify the magnitude and duration of actinic pigment and photodamage response in patients of Fitzpatrick Skin Phototypes (SPT) I-IV who underwent two treatments with a fractionated, nonablative 1927 nm thulium laser (MOXI™, Sciton).

The authors conducted an IRB-approved, single-center, prospective, nonrandomized study to evaluate the efficacy of f1927 nm nonablative lasers in the treatment of diffuse dyspigmentation and actinic irregularities. Patients underwent two treatments with f1927 nm nonablative laser at a 1-month interval. F1927 nm treatment and energy parameters included a pulse energy of 15 mJ, density of 15% with 15% coverage, and six total passes. The primary endpoint for this study was pigment response after treatment, measured using the VISIA Skin Imaging and Analysis System (Canfield Scientific). Pigmentary lesions measured and analyzed included spots, UV spots, and brown spots. The Physician's Global Assessment Scale was used by plastic surgeons to provide a subjective clinical assessment of melasma response. Nonparametric testing was used to assess and compare VISIA results across the study period as well as clinician evaluations. A p value ≤ 0.05 was considered statistically significant.

Twenty-seven patients underwent two treatments with nonablative, f1927 nm laser in May and June 2022. Ninety-six percent of patients (n = 26) completed 1-month follow-up and 89% of patients (n = 24) completed 3-month follow-up. The study cohort was 100% female, with a mean ± SD age of 47.0 ± 11.5 (range: 29-74), and a mean Fitzpatrick SPT of 2.8 (range: I-IV). No serious adverse events were observed during study treatment or follow-up. Overall, analysis showed statistically significant improvements in dyspigmentation at 1 month and an increase in pigment toward baseline at 3 months. At 1 month, there was a statistically significant decrease in spots (p = 0.002), UV spots (p < 0.001), and brown spots (p < 0.001) compared to baseline. At 3 months, Brown spots remained significantly improved compared to baseline (p = 0.05). Analysis showed 9.9% improvement in pigment on the left (p < 0.0001) and 7.5% improvement in pigment on the right (p < 0.0001) face. Right dyspigmentation remained significantly improved at 3-month follow-up (p = 0.02). Subjectively, clinician evaluators' mean Physician's Global Assessment Scale score was 3.4 (p < 0.0001) at 1-month follow-up and 3.7 (p < 0.0001) at 3-month follow-up, which correspond to an approximately 50% improvement hyperpigmentation when at both time points.

These results demonstrate that fractionated, nonablative 1927 nm laser treatment is an effective modality for improving clinical and subclinical photodamage. The magnitude and duration of pigment improvement are potentially influenced by the propensity for photodamage during the summer months, which may suggest the need for multiple f1927 nm treatments over time to maintain results.