Comparison of 1,550-nm Laser and Fractional Radiofrequency Microneedle for the Treatment of Acne Scars in Ethnic Skin

Overview

The primary objective of this randomized, split-face, controlled study is to compare the efficacy and safety of a erbium-doped 1,550-nm non-ablative fractional laser and a bipolar fractional radiofrequency microneedle device for the treatment of atrophic facial acne scars in ethnic skin (Fitzpatrick Skin Phototypes III-VI). The hypothesis of this study is that both erbium-doped 1,550-nm non-ablative fractional laser and the bipolar fractional radiofrequency microneedle device are equally effective for the treatment of atrophic acne scars in ethnic skin (SPT III-VI). However, the bipolar fractional radiofrequency microneedle device has less adverse effects than erbium-doped 1,550-nm non-ablative fractional laser due to the absence of scattering and the absence of chromophore-specific targets - predominantly melanin - traditionally needed with laser treatments; hence the fractional radiofrequency microneedle device will have a higher safety profile in darker skin types .

Acne is a highly prevalent disease and post-acne scaring has shown to have detrimental effects on a person's physical, mental, and social well-being. Acne scars can be divided in general categories of hypertrophic or keloid scars, atrophic scars (icepick, rolling, boxcar), and pigmentation alterations (redness, hypo and hyper-pigmentation). This study will focus on treatment of moderate to severe grades of atrophic acne scarring. Our aim is to compare the efficacy and safety of a erbium-doped 1,550-nm non-ablative fractional laser and a bipolar fractional radiofrequency microneedle device for the treatment of atrophic acne scars in ethnic skin (Fitzpatrick Skin Phototypes III-VI) by performing a split-face randomized controlled trial. Both devices in this study are already FDA approved treatment modalities for acne scarring. History of erbium-doped 1,550-nm non-ablative fractional laser (Fraxel® Restore Laser System, Solta Medical, Inc., Hayward, CA): Non-ablative fractional lasers work via the theory of fractional photothermolysis, which creates hundreds to thousands of microscopic thermal zones (MTZs), or columns of thermally injured skin, while sparing the surrounding tissue. The pixilated nature of treatment and the functionally unimpaired stratum corneum allow for rapid tissue healing and allows for safer treatments of our patients. Mechanistically, fractional photothermolysis allows controlled amounts of high energy to be delivered deep within the dermis resulting in collagenolysis and neocollagenesis, which smoothes the textural abnormalities of acne scarring. Multiple published studies have demonstrated that erbium-doped 1,550-nm non-ablative fractional laser ("NAFL") can be successfully utilized in the treatment of all forms of atrophic acne scarring - ice-pick, boxcar, and rolling scars - with a very favorable safety profile in all skin types, and thus, has been cleared by Food and Drug Administration (FDA) for that particular indication. According to the manufacture manual (reference attached in the "Attachments" section), NAFL is indicated for "use in skin resurfacing procedures as well as treatment of acne scars, surgical scars, lentigos (age spots), solar lentigos (sun spots), actinic keratosis, and melasma." History of the fractional radiofrequency microneedle device (Fractora; Invasix Ltd./InMode MD Ltd., Israel): Fractional radiofrequency is not a laser. Instead, these devices use an array of electrodes that allows for zones of thermal wounds to be created between areas of unaffected zones, thus stimulating dermal remodeling and allowing for a supply of reservoir cells to promote healing. Variations of fractional radiofrequency exist that employ microneedles to deliver electrical current to a particular depth within the dermis that decreases damage to the epidermis. These fractional radiofrequency microneedle devices provide an alternative to conventional methods of acne-scar treatment (such as NAFL). Great interest has been culminating over the recent years for the use of such devices in acne scars due to the absence of light scattering and the absence of chromophore-specific targets traditionally needed with laser treatments. As melanin is not a target, it is felt to have a higher safety profile in darker skin phototypes. A recent study investigated the safety and efficacy of a specific bipolar fractional radiofrequency microneedle device (Fractora; Invasix Ltd./InMode MD Ltd., Israel) for acne and acne scarring. In this study, 8 patients with acne scars were reported and it was noted that all patients (regardless of their skin phototypes) had improvement in their active acne and acne scars after 4 treatments and a 1 month, on average follow-up period. The treatment was well tolerated without any side-effects. Skin biopsies from this study showed reduction in scar depth and new collagen formation with an increase in elastic fibers and adnexal structures noted. A follow-up report showed that 4 out of 8 patients who were in the original study returned for a long term follow-up from 1 to 2 years, that showed ongoing clinical improvements in these patients. This specific bipolar fractional radiofrequency microneedle ("FRM") device has been FDA-approved for acne scars and skin rejuvenation. To this date the efficacy and safety of 1,550-nm fractionated photothermolysis system has not been compared to a fractional radiofrequency microneedle device for atrophic acne scars in ethnic skin in a randomized split-face controlled trial. A major advantage of a split-face self-controlled design would be to minimize any confounding factors. Laser resurfacing has been well studied and is widely used in individuals with fair skin - Fitzpatrick skin phototypes (SPT) I to II. However, there is a paucity of published studies involving individuals with darker skin types (SPT III-VI)-a population that has a higher risk of laser-associated dyspigmentation.