Table 1. Summary of studies conducted on the use of dermal fillers in the treatment of atrophic acne scars.
| Study | Indication | Aim | No. of patients | Finding | |
|---|---|---|---|---|---|
| HA (temporary) | |||||
| Mahamoud et al. (2020)23 | Patients with acne scars received HA injections, or PRP injections, on each face's side for comparison. Brand name: Viscoderm. |
Patients underwent three sessions of full-face fractional CO2 laser, immediately followed by intradermal HA injections or PRP injections on each side of the face with four weeks between sessions. | 30 | Using qualitative and quantitative Goodman and Baron, both sides had a significant reduction in the severity of acne scars. Collagen and elastic fiber content increased in both, but more in the PRP-treated side. | |
| Kim et al. (2019)22 | HA pneumatic injections were given to Fitzpatrick skin types IV~V patients with acne scars. Brand name: Unial. |
Patients underwent a single treatment session. Follow-ups were given 1 and 2 months after treatment. | 10 | The mean scar volume values were 0.964, 0.741, and 0.566 mm3, respectively, at baseline, one month, and two months after the injection. No adverse events were reported. | |
| Dierickx et al. (2018)21 | HA fillers were used to treat patients with moderate to severe acne scars. Brand name: Restylane. |
Patients received three sessions of HA filler four weeks apart. Results were assessed up to 36 weeks after treatment. | 12 | Scar severity has improved in most patients (67%). Patient satisfaction with the overall facial appearance and with the sensation and perception of the skin improved in most patients. Patients' self-esteem and self-confidence also improved. AEs were redness, swelling, bumps, pain, and bruising (all resolved in 2 weeks). | |
| Goodman and Van Den Broek (2016)20 | HA fillers were used with the vertical modified tower technique. Brand name: Juvederm Voluma (Allergan). |
Patients were treated twice with three months follow up after the second treatment. | 5 | The mean scar count reduced from 48.8 to 15.4 after the second session. The static objective grading scale demonstrated improvement from 3.2 prior to first treatment to 2.6 at the final review. | |
| Patel and Tevet (2015)19 | HA pneumatic injections were given to patients who had Fitzpatrick skin types IV~V with acne scars. Brand name: Belotero Balance. |
Patients received two sessions at 4-week intervals of pneumatic, needleless injections of crosslinked HA. Follow up were given three months later. | 2 | Patient 1: acne scar grade improved from 2 to 1. Patient 2: acne scar grade improved from 3 to 2. No AEs were reported. |
|
| Halachmi et al. (2013)18 | HA pneumatic injections were given to patients who had Fitzpatrick skin types IV~V with acne scars. Brand name: Unial. |
20 mg/ml microinjections of HA were used, and follow-ups were given 1~2 months later, with one follow-up visit. | 12 | Immediate visual improvement was noticed in all scars. Pinpoint bleeding at the injection site was the only reported AE. | |
| Hasson and Romero (2010)17 | HA fillers were used to treat facial atrophic scars caused by acne vulgaris, dog bites, piercing, basal cell carcinoma, and leishmaniasis. Brand name: Esthelis. |
The injection technique was linear threading, serial puncture, or both. Follow-ups for assessment of the injection were given immediately, one week, and one month after the injection. | 12 | The authors assessed the results immediately, one week, and one month after the injection. 27% had moderate improvement, 57% had good improvement, and 17% had excellent improvement. Mild erythema was the only reported AE. |
|
| PLLA (semi-permanent) | |||||
| Sapra et al. (2015)25 | PLLA injections were given for the treatment of atrophic acne rolling scar. Brand name: Sculptra. |
Single-arm, unblinded, open-label phase 2 study. Patients received 3 to 4 sessions if needed at four weeks intervals—follow-ups are given after six months from the first session. | 22 | 45.5% to 68.2% of patients reported excellent improvement using photographs. Subject treatment satisfaction scores increased by 44%. AEs included one patient with a non-visible, palpable nodule. |
|
| Rkein et al. (2014)26 | Ablative fractionated CO2 laser and topical PLLA immediately after to improve atrophic scars. Brand name: Sculptra. |
An uncontrolled, prospective study. Most of the patients had only one treatment session with laser and PLLA. The follow-up duration was three months after the laser and PLLA. |
19 | Patients had 95% scar improvement with minimalAEs, such as mild pain, erythema, and edema. One patient developed an epidermal inclusion cyst. | |
| Sadick and Palmisano (2009)27 | PLLA injections were given to a 60-year-old white woman who had previously been treated with CO2 laser resurfacing without improvement on acne scars. Brand name: Sculptra. |
Seven sessions of PLLA were given to individual acne scars. The patient was followed up twice; the first was six months after the last session, and the second 14 months after the previous session. | 1 | The patient reported a good improvement with minimal swelling and bruising at injection sites lasting 5~7 days. | |
| Sadove (2009)28 | PLLA to correct dermal fat loss in macular atrophic acne scarring Brand name: Newfill. |
Both patients received three sessions over 12 weeks. The first follow-up was one year after the last session, and the second was four years after the previous session. | 2 | Both patients reported marked improvement with only minimal swelling and redness. | |
| Beer (2007)12 | PLLA fillers were used to treat patients with moderate to severe acne scars. Brand name: Sculptra. |
Single-center, open-label, prospective study with seven sessions of PLLA. Injections were given at 1-month intervals. Patients were followed up after each treatment session. | 20 | A noticeable reduction in acne scar size. | |
| CH (semi-permanent) | |||||
| Goldberg et al. (2006)31 | Use of CH in acne scars. Brand name: Radiesse |
Open study. Subjects underwent 1~2 injection sessions. Follow up duration was 12 months. | 10 | Depressed acne scars responded to treatment, but no response from icepick scars. No significant AEs. | |
| Koren et al. (2019)32 | Combination of CH and EBD in acne scars. Brand name: Radiesse |
A single center retrospective study reviewed medical records of acne scar patients between 2013~2016 who were treated with one of four treatments: ablative fractional CO2 laser, a radiofrequency bipolar device, a 1,540 nm non-ablative fractional laser, and injection of CH. | 352 | Injection of CH-based fillers 2~4 weeks prior to the treatment with ablative fractional CO2 laser yields a better outcome and should be recommended for suitable patients. | |
| PMMA (permanent) | |||||
| Joseph et al (2019)34 | PMMA to treat acne scars over the entire face. Brand name: Bellafil |
Open-label, multicenter, single-arm non-randomized study. Patients received two treatment sessions with one month in between. Patients were followed up for seven months. | 42 | Using the acne scar assessment scale (ASAS), lower face responders were 92% and 97% at the 4- and 7-month marks, respectively. Upper-face responders were 64% and 67% at the 4- and 7-month marks, respectively. Only two reported skin testing-related AEs, and no AEs were attributed to PMMA dermal filler. | |
| Karnik et al. (2014)39 | Treatment of atrophic acne scars over the cheeks using PMMA dermal fillers. Brand name: Artefill. |
A double-blind, multicenter, randomized controlled trial. Patients received two treatment sessions with six months of follow-up. | 147 | Using Acne Scar Rating Scale, PMMA treatment improved 91% of the treated scars. In contrast, the investigators reported improvement in only 76% of the scars treated with saline. AEs were minimal. | |
| Epstein and Spencer (2010)40 | PMMA fillers were used for the treatment of atrophic acne scars. Brand name: Artefill. |
Pilot study. Patients had only one injection session, with eight months of follow-up. | 14 | At the eight months mark, investigators reported that 96% of treated scars showed some improvement. No AEs were reported. | |
| Carvalho Costa et al. (2009)13 | PMMA fillers were used to determine their efficacy and safety as a facial filler. Brand name: Artefill. |
Patients had 1~4 sessions with a 2-month interval. They were followed up for up to 9 years, with follow-up visits at each session, at one month and six months, then yearly thereafter. | 25* | Using physical examination and before-and-after photos at 1 and 6 months, then yearly to assess the improvement, more than 85% of subjects were satisfied with their results. Most patients experienced no AEs (80%), and mild, transient AEs were reported by 20% of patients. | |
| Silicone (permanent) | |||||
| Barnett and Barnett (2005)42 | Silicone liquid injections were used to assess the improvement of acne scars. | Monthly liquid silicone injections using a technique known as the microdroplet, multiple-injection approach. Patients were followed up for 30 years, with follow-up immediately and then at 10-, 15- and 30-years posttreatment. | 5 | Investigators noticed an improvement in acne scars with liquid silicone injection immediately after treatment, at 10, 15, and 30 years, although the improvement was not quantified. Only minor AEs were reported. | |
HA: hyaluronic acid, PLLA: poly-L-lactic acid, CH: calcium hydroxyapatite, EBD: energy-based device, PMMA: polymethylmethacrylate, AE: adverse event. *Total patient number with different diagnoses. Of those, 25 patients received PMMA dermal filler for atrophic acne scars.