Using normal and high pulse coverage with picosecond laser treatment of wrinkles and acne scarring: Long term clinical observations
Authors: Dierickx Christine 
Published: November 2017

Objective

The picosecond 755 nm alexandrite laser using a diffractive lens array has demonstrated consistent clinical efficacy for improving the appearance of acne scarring and wrinkles amongst other benefits. This small pilot study is to assess the difference, if any, in clinical benefit if a higher than the standard protocol for number of pulses delivered to a tissue area is used compared to the standard protocol guidelines.

Method

Seven subjects received treatment to one side of the face with a standard protocol number of laser pulses with the other side of the face receiving higher than standard number of pulses from the same 755 nm picosecond laser using an additional diffractive lens array. Photographs at final follow up were compared to baseline by two blinded Board Certified Dermatologists and assessed for improvements to acne scarring using a 6‐point grading score, for wrinkles using the Fitzpatrick Wrinkle & Elastosis 3‐point grading scale and a Global Aesthetic Improvement Scale assessment. Subjects also completed a satisfaction questionnaire.

Results

For the acne scarring subjects, the average improvement from baseline to final follow up was 4.0 +/− 1.0 for the standard treated side and 4.5 +/− 0.5 for the high pulse side. There was no statistically significant difference between the two treated sides (P > 0.05, n = 3 paired t‐test). For the wrinkle subjects, the average grading of the standard pulse side improved from 2.0 +/− 0.82 to 1.75 +/− 1.0 from baseline to final follow‐up. The high pulse side improved from 1.5 +/− 1.0 to 1.125 +/− 0.25 from baseline to final follow‐up. There was no statistically significant difference between the improvement of the standard and high pulse treatment sides (P > 0.05, n = 4 paired t‐test). The comparison of baseline to final follow‐up images of each subject found both sides to be Much or Very Much improved with no statistically significant difference between the standard and high pulse sides (P > 0.05, n = 7 paired t‐test). Six of the seven subjects did not note any difference between the effect on different sides of the face and four of the seven rated their overall improvement after treatment as Good, three subjects as Reasonable and one subject with Slight Improvement. All subjects found the treatment comfortable and easy to tolerate and there was no increased incidence of side effects other than the mild occurrences typically observed for this type of treatment.

Conclusion

This is a small pilot study with limited subject numbers and further data is needed to be able to make firm conclusions of observed trends, which suggest that the use of higher than standard suggested protocol number of pulses with the diffractive lens array and the 755 nm picosecond laser does not appear to offer any additional benefit over that that can already be achieved with the standard number of pulses, but also does not increase risk of detrimental post treatment effects either. Lasers Surg. Med. 50:51–55, 2018. © 2017 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.