Evaluation of Picosecond 755-nm Alexandrite Laser With a Diffractive Lens Array on Pore Size Reduction

Objectives: Medications, lasers and light therapy have all been shown to transiently minimize pore size. Current research of the 755-nm Alexandrite picosecond laser (Cynosure, MA) on pore size shows differing results regarding the efficacy, with one study of Asian volunteers (Fitzpatrick skin type IV) reporting “marked” improvement of pores, yet another study reporting no significant improvement in pore size in Chinese patients (Fitzpatrick skin type III–IV), causing some contention. This study aims to rectify the discordant results through the examination of the 755-nm Alexandrite picosecond laser on pore size reduction in a sample consisting of Fitzpatrick skin type I–III.
Methods: Patients who received 755-nm Alexandrite picosecond laser treatment for photorejuvenation, (6 mm lens array) with a fluence of 0.71 J/cm2 of the face or head, with at least two treatments over four-week intervals were included in the study. A precision subject imaging system (Canfield VISIA^® Complexion Analysis Generation 7, NJ) was used to assess three parameters of pore size (feature count, score, percentile rank) at each time period at right lateral, left lateral and frontal views. A Wilcoxin signed rank test was performed to compare differences between time periods and a mixed model ANOVA was utilized to account for patients who received less than three treatments. Significance level set to P=<0.05.
Results: 32 participants met criteria and underwent at least two picosecond laser treatments for photorejuvenation. There was an overall reduction in pore count in approximately 57% of participant data points from times 1 to 2 and 50% reduction from times 2 to 3. There was a 100% pore count reduction observed from baseline compared with the follow-up visit four weeks after the third treatment, at time 4. Further, there was a significant improvement of pores demonstrated by score from times 1 to 3 (Z= -2.197, P=0.028) as well as percentile rank between times 1 and 2 (Z= -2.070, P=0.038) and times 1 and 3 (Z= -2.201, P=0.028).
Conclusion: Future studies should investigate the longterm effect of 755-nm Alexandrite picosecond laser on pore size reduction as continued patient recruitment and data collection is necessary to effectively discern the 755-nm Alexandrite picosecond laser debate. Thus, prolonged follow up post treatment should be evaluated in order to determine if results are maintained. Nonetheless, the 755-nm Alexandrite picosecond laser shows promising results for the improvement of skin pores thus far.

J Drugs Dermatol. 2021;20(12):1302-1306. doi:10.36849/JDD.6199