Safety and Effectiveness of Microfocused Ultrasound With Visualization for the Correction of Moderate to Severe Atrophic Acne Scars

November 2019 | Volume 18 | Issue 11 | Original Article | 1109 | Copyright © November 2019

Corey S. Maas MD,a John H. Joseph MDb

aThe Maas Clinic, San Francisco, CA

bClinical Testing of Beverly Hills, Beverly Hills, CA

Abstract
Objective: To assess the effectiveness of microfocused ultrasound with visualization (MFU-V) for treating moderate to severe atrophic acne scars.

Design: Healthy subjects (N=20) seeking correction of moderate to severe atrophic acne scars on the cheeks and/or temples were enrolled. Scars were predominantly rolling- and boxcar-type, affecting an area ≥5.0cm2. Eighteen subjects completed the study.

Intervention: The treatment area was marked with 14mm2 and 25mm2 squares and treated with four transducers: 7 MHz (3.0mm focal depth) and 10 MHz (1.5mm focal depth), each in 14mm and 25mm widths. During each session, MFU-V treatment lines were applied 2-3mm apart, within each treatment area, with a maximum length of 25mm. Each square received 30 treatment lines at two transducer depths (60 total lines). Subjects received three total treatments, with 30 days between each session. The primary outcome measure was improvement in baseline appearance of scars at 90 and 180 days after the final treatment. Secondary outcome measures included changes in severity using an Acne Scar Improvement Scale (ASIS) and Global Aesthetic Improvement Scale (GAIS) at 60-, 90-, and 180-days post-treatment, and a satisfaction questionnaire at 90-days post-treatment.

Results: Among the 90-day images available for assessments (n=11), 100% were rated as improved by blinded reviewers, and 64% of pre- and post-treatment images were correctly selected. Among 180-day images (n=15), 100% were rated as improved, and 40% of pre- and post-treatment images were correctly selected. Most subjects were determined to have 25-50% improvement in investigator ASIS scores at 60-, 90-, and 180-days post-treatment. All subjects noted some improvement in severity at the 60-day assessment when measured using ASIS. Based on investigator GAIS scores, 100% of subjects were “Improved” or “Much Improved” at 60-, 90-, and 180-days post-treatment. Based on subject GAIS scores, all subjects noted improvement at the 60-day assessment, and 83% and 89% at the 90- and 180-day assessments, respectively. Overall, 17 subjects (94.4%) expressed some degree of satisfaction at 90-days post-treatment.

Conclusions: The results of this study demonstrated that MFU-V therapy is beneficial and well tolerated for the treatment of rolling- and boxcar-type acne scars.

J Drugs Dermatol. 2019;18(11):1109-1114.

INTRODUCTION

Acne vulgaris is an exceedingly common skin disorder with a reported prevalence ranging from 75%1 to more than 90%2 in adolescents, and this condition often persists into adulthood.3,4 Acne affects both genders equally2 and all racial groups.5,6 The negative impact of acne on patient self-esteem, psychosocial functioning, and overall quality of life is the topic of numerous publications.7-10

An unfortunate long-term consequence of severe acne is scarring. Acne scars have been reported to occur with a frequency as high as 11% in men and 14% in women.11 In one acne study, 1% of patients had scars, and 1 in 7 (14%) scars was considered disfiguring.4 The severity of acne scarring has been correlated with overall acne severity and the duration of untreated acne.12 A delay of up to 3 years between acne onset and adequate treatment corresponded with the final extent of scarring.12 Facial scarring is associated with diminished quality of life13 and negative perceptions by society.14

While the etiology of acne scarring is not well understood, it is thought to result from skin damage during the healing process following active acne.3 Depending on changes in skin collagen, acne scars are classified as atrophic or hypertrophic. Most (80 to 90%) are atrophic scars caused by the loss of collagen.3 Based on morphology, atrophic scars are subclassified as ice pick (60 to 70%), boxcar (20 to 30%), or rolling scars (10 to 15%).3 Histological examination of acne-scar tissue revealed decreased dermal thickness and loss of pilosebaceous units, inflammatory cell infiltrates, and inadequate dense collagen-fiber deposition in the whole dermis.15