Clinical Outcome of 1064-nm Picosecond Neodymium–Doped Yttrium Aluminium Garnet Laser for the Treatment of Hypertrophic Scars

Picosecond lasers in cosmetic dermatology: where are we now? An overview of types and indications

Q-switched lasers have undeniably revolutionized the field of laser dermatology since four decades ago. Just as the first-generation laser emits its photonic signal in a few nanoseconds, the picosecond laser delivers pulse widths of at least ten times shorter. These devices offer a powerful tool for treating a wide range of skin conditions with a minimal downtime for visible improvement. For the current study, a literature research was performed on the dermatological applications of picosecond laser. The literature searched on this topic between 1999 and 2023 accessible through various platforms produce a result of 62 articles. The included studies have discussed the application of picosecond laser technology in tattoo removal, treatment of epidermal and dermal pigmentation, and collagen remodeling. After sifting the data from the articles into tables, the results were discussed in detail. The study shows a lot of evidence towards the efficacy of picosecond laser, yet it draws attention to its downsides.

Efficacy and safety of low-dose oral isotretinoin monotherapy versus combined therapy with picosecond laser for the treatment of acne scars in Asian population

PURPOSE

Acne scars are common in patients with moderate to severe acne. Isotretinoin is the first-line treatment for those patients, but whether oral isotretinoin can improve acne scar is not clear. Picosecond lasers (FxPico) has been reported to improve acne scars. In the present study, we evaluated the clinical efficacy of low-dose isotretinoin with or without FxPico treatment for acne scars.

MATERIALS AND METHODS

A total of 48 patients with acne scars were enrolled and were randomly assigned to receive low dose oral isotretinoin or not. For all the patients in both treatment groups, one side of face were randomly assigned to be treated with picosecond laser. Assessments, including photos, échelle d'évaluation clinique des cicatrices d'acné (ECCA) and Global Acne Grading System (GAGS) score, the number of lesions, melanin and erythema indexes, transepidermal water loss were assessed at 0, 1, 2, and 3 month. Side effects, Dermatology Life Quality Index (DLQI) and satisfaction were recorded before and after the study.

RESULTS

A total of 44 patients completed the study (24 received oral low dose isotretinoin and 20 did not). Low dose oral isotretinoin treated group showed significant improvement on ECCA (from 112.5 [50-180] to 105 [50-160]), GAGS score (from 12.6 ± 3.3 to 10.1 ± 3.0), the count of papules (from 4.3 ± 3.7 to 1.0 ± 1.5) than the blank group, and higher improvement were noticed after isotretinoin combined with FxPico. All the side effects were temporary and tolerable, no adverse effects were observed. Higher DLQI and patients' satisfaction were achieved by oral isotretinoin alone and isotretinoin combined with FxPico.

CONCLUSIONS

This is the first paper showing the improvement of scars by early low dose-isotretinoin intervention with or without the combination of picosecond laser. Early intervention with oral low-dose isotretinoin is effective for the treatment and prevention of acne scars, the combined therapy with FxPico can achieve better outcome.

Hypertrophic Scars and Keloids: Advances in Treatment and Review of Established Therapies

Hypertrophic scars and keloids can have significant detrimental effects on patients both psychosocially and functionally. A careful identification of patient risk factors and a comprehensive management plan are necessary to optimize outcomes. Patients with a history of dystrophic scarring should avoid unnecessary procedures and enhance the wound-healing process using various preventive strategies. As there is no single, fully efficacious treatment modality, prevention remains the best approach in reducing aberrant scar formation. When prevention therapies fail, keloids have been shown to be respond to a variety of therapies including topical and injectable corticosteroids, 5-fluorouracil, radiotherapy, lasers, and surgical excision, all with varying efficacies. As such, management should be tailored to the individual patient's risk factors with the use of combination therapies to reduce recurrence rates. Still, keloid and hypertrophic scar therapies are widely diverse with novel treatment modalities providing alternatives for recurring lesions. Laser-assisted drug delivery, skin priming, and novel topical therapies may provide alternative options for the management of hypertrophic scars and keloids.

Hypertrophic Scars of the Hand: The Role of Electrophotobiomodulation Theory as a Recent Line of Treatment

BACKGROUND

A more enduring strategy for the treatment of hypertrophic scars of the hand is still a challenge facing restorative dermatologists and plastic surgeons. Nonetheless, with the use of nonablative devices, intense pulsed light and different types of lasers have started to yield promising outcomes and are close to becoming an effective and dependable technique. The advances in radiofrequency energy have brought new life to optical-based frameworks. Radiofrequency current delivers an unadulterated heat effect according to the electrical response characteristics of each tissue. The purpose of this study was to assess the patient satisfaction, safety, and clinical efficacy of the use of electrophotobiomodulation (combined intense pulsed light and radiofrequency energy) in the treatment of postburn hypertrophic scars of the hand.

METHODS

This was a prospective clinical study that was performed on 56 patients who presented with postburn hypertrophic scars on the hands between March of 2013 and January of 2020.

RESULTS

The clinical appraisal showed excellent results in 33 patients (58.9%), good results in 18 patients (32.2%), fair results in five patients (8.9%), and no poor results.

CONCLUSION

The use of radiofrequency energy combined with intense pulsed light was effective for the treatment of hand scars on people with various skin tones.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Early acne scar intervention with 1064 nm picosecond laser in patients receiving oral isotretinoin: a randomized split-face controlled pilot study

Early acne scar intervention is important. Oral isotretinoin is widely used in patients with moderate to severe acne. Picosecond laser has shown a promising effect on scar clearance. However, there is a lack of reports on the efficacy and safety of early acne scar management by using 1064-nm picosecond laser in patients receiving low-dose oral isotretinoin. Twenty-four patients with atrophic acne scars of Fitzpatrick skin type III to V were enrolled. All patients were receiving low-dose oral isotretinoin (0.12-0.22 mg/kg/day) during the treatment. The face of the participants was randomly assigned to receive 2 sessions of fractional picosecond 1064 nm Nd: YAG laser (FxPico) treatment and 2 follow-ups, with an interval of 1 month (month 0-3). Clinical efficacy and safety were assessed by photographs, ECCA grading scale, the number of scar lesions melanin and erythema indexes (MI and EI), TEWL, DLQI, and patient satisfaction and the adverse events were recorded on every visit. FxPico significantly decreased the ECCA score and showed higher improvement in the ECCA score. FxPico treated side achieved a significant reduction in all acne scar types, while only boxcar scars and rolling scars showed higher improvement. TEWL but not MI or EI were significantly improved. DLQI and patient satisfaction were higher with the FxPico-treated side than control side. No adverse effects were observed and all the side effects observed were temporary and tolerable. Early intervention by FxPico on patients receiving low-dose oral isotretinoin is a safe and effective modality to improve atrophic acne scars.

Molecular Features of Hypertrophic Scars After Thermal Injury: Is There a Biologic Basis for Laser Therapy?

Significance: Hypertrophic scars (HTS) and keloids are common after thermal injuries and other trauma to deep regions of dermis of the skin. These abnormal scars can cause contractures and the thick masses of scar tissue that result in functional and cosmetic impairment. Management of these dermal fibrotic conditions includes a wide range of medical and surgical treatments, which can be time consuming, only partially effective, and often uncomfortable for patients. Recent Advances: The molecular pathophysiology of HTS has become more understood over the past two decades, where thermal injury to the reticular dermis results in an inflammatory response, fibrogenic growth factor release, and the formation of a dermal scar with increased collagen and proteoglycan composition in an abnormal morphology. Lasers are becoming a widely used form of treatment for these types of scars; however, the evidence for the beneficial effects of laser treatments and the understanding of their mechanism of action are still evolving. Critical Issues: Paradoxically, laser delivery of thermal energy to the skin is suggested to improve scar remodeling and wound healing, yet HTS is a well-recognized complication of excessive thermal energy delivered by laser treatments. This review aims to examine the current evidence for the use of lasers for HTS, and to investigate the molecular mechanisms where re-injury of a burn scar from laser treatment could result in overall improvements in scar quality. Future Directions: Improved design of clinical trials for the treatment of scarring in the future will evolve from new methodology and models of HTS in animals and humans.

Efficacy of the Neodymium-Doped Yttrium Aluminum Garnet Laser in the Treatment of Keloid and Hypertrophic Scars: A Systematic Review and Meta-analysis

BACKGROUND

Keloid and hypertrophic scars are the most common types of pathological scars. They can cause itching, pain, erythema, and psychological stress due to cosmetic problems, decreasing the quality of life for affected individuals. The neodymium-doped yttrium aluminum garnet (Nd:YAG) multipurpose laser is used to treat pathological scars, and studies have shown that the Nd:YAG laser can markedly improve scarring.

AIMS

We performed a meta-analysis to evaluate the efficacy of the Nd:YAG laser in the treatment of keloid and hypertrophic scars.

METHODS

A literature search of PubMed, Web of Science, Scopus, Cochrane, Embase, CNKI, and Wanfang was performed between January 1st, 2010, and July 14th, 2021. The Vancouver Scar Scale (VSS) was used to evaluate treatment outcomes. We used the R version 4.0.0 software for statistical analysis.

RESULTS

The Nd:YAG laser improved the condition of keloid and hypertrophic scars and reduced VSS score (mean difference [MD]: 2.96, 95% confidence interval [CI]: 2.08-3.84, p < 0.01). There was no obvious difference in the results between regions. A subgroup analysis by scar type revealed that the curative effect of the Nd:YAG laser on keloid scars (MD: 2.02, 95% CI: 0.58-4.63, p = 0.10) was less marked compared with that on hypertrophic scars (MD: 3.05, 95% CI: 1.58-4.52, p < 0.01). With the combined use of the Nd:YAG laser and other treatment methods, a more significant change in VSS score was noted (MD: 4.28, 95% CI: 2.07-6.49).

CONCLUSIONS

This meta-analysis showed that the Nd:YAG laser can improve the condition of keloid and hypertrophic scars and effectively reduce VSS score. Moreover, the curative effect of this approach on keloid scars is less marked compared with that on hypertrophic scars.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Acne scar treatment using high-energy fractional nanosecond Q-switched 1064 nm laser

Aims

The objective of this study was to evaluate the effectiveness and safety of high‐energy ablative fractional nanosecond Q‐switched 1064 nm laser therapy for acne scars.

Material and methods

Forty‐six patients aged from 16 to 69 years and of Fitzpatrick skin type from 2 to 4 were included in this retrospective study. Multiple passes were delivered with a fractional 1064‐nm handpiece at high energy. Results were evaluated using blinded analysis of patient before and after photographs and also by evaluating patient satisfaction.

Results

Most patients (75%) were improved or very improved according to blinded evaluation. Patient satisfaction was high. No hypo/hyperpigmentation, scarring, or any other side effects were reported by any of the patients.

Conclusions

The study demonstrated good clinical outcomes in facial acne scar management with a high patient satisfaction rate and no adverse side effects.

Comparison of 1064-nm and Dual-Wavelength (532/1064-nm) Picosecond-Domain Nd:YAG Lasers in the Treatment of Facial Photoaging: A Randomized Controlled Split-Face Study

BACKGROUND AND OBJECTIVES

To compare the efficacy and safety of 1064-nm and dual-wavelength (532/1064 nm) picosecond Nd:YAG lasers with a holographic optic in the treatment of facial photoaging.

STUDY DESIGN/MATERIALS AND METHODS

In this prospective, randomized split-face study, each half of each participant's face was randomly treated with a 1064-nm or 532/1064-nm picosecond laser. All participants underwent five treatment sessions and follow-up visits 1 and 3 months after the final treatment. The primary outcomes were measured as the global photoaging scores, determined by two physicians who were blinded to the treatments. The secondary outcomes were the participant-assessed Global Aesthetic Improvement Scale (GAIS) and satisfaction scores. Histopathological examinations were performed.

RESULTS

Global photoaging scores decreased significantly after treatment with either laser. The global photoaging scores, GAIS scores, and satisfaction scores did not differ significantly between the 1064-nm and 532/1064-nm picosecond laser treatments. Histological changes were similar between the two groups. Intraepidermal vacuoles and dermal hemorrhaging were observed immediately and 24 h after treatment. After five treatments, neocollagenesis was observed in the upper dermis of both groups, and elastic fibers were more elongated and orderly.

CONCLUSIONS

Treatments with 1064-nm and 532/1064-nm picosecond Nd:YAG lasers were comparably effective at improving photodamaged facial skin by remodeling the collagen and elastin network through laser-induced optical degradation and vascular damage.

Picosecond Laser treatment of Striae Distensae: In vivo Evaluation of Results by 3D Analysis, Reflectance Confocal Microscopy, and Patient's Satisfaction

BACKGROUND AND OBJECTIVES

The efficacy of picosecond laser (PSL) in the treatment of striae distensae (SD) has been recently reported; otherwise, the base for this improvement has not been clarified yet. The aim of this study is to treat long-lasting SD with PLS and to describe their in vivo morphological variations after treatment using three-dimensional (3D) imaging and reflectance confocal microscopy (RCM).

STUDY DESIGN/MATERIALS AND METHODS

A total of 27 patients asking for treatment for SD were treated with four monthly sessions of PLS. Clinical improvement was estimated through a blinded evaluation performed by two independent dermatologists, Global Assessment Improvement Scale (GAIS), patients' satisfaction, 3D imaging, and RCM assessments at baseline and 6 months after the last laser session.

RESULTS

Although a clinical improvement of SD was observed in 81.4% of patients according to physicians' GAIS, only 66.6% of patients reported subjective improvement and satisfaction after treatment (P = 0.04). 3D imaging revealed a significant improvement in terms of skin texture (P < 0.001) and mean SD depth (P < 0.001). Otherwise, RCM highlighted collagen remodeling and the appearance of new dermal papillae in all the treated SD compared with baseline.

CONCLUSIONS

The present study confirms that PLS represents a safe treatment option for SD; herein, we report morphological documentation of skin variations after PLS treatment. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

Histological Characteristics of Skin Treated With a Fractionated 1064-nm Nd: YAG Picosecond Laser With Holographic Optics

BACKGROUND AND OBJECTIVES

Picosecond lasers (PSL) constitute a significant technological advancement and exert rejuvenating effects upon the skin. This study was conducted to investigate changes in the skin upon treatment with the fractionated 1064-nm Nd: YAG PSL through in vivo and ex vivo human histological analysis.

STUDY DESIGN/MATERIALS AND METHODS

In vivo back skin specimens were treated with a fractionated 1064-nm PSL at 1.3, 2.1, and 2.9 mJ fluence for two passes, and 2.9 mJ for 10 passes, and then stained with hematoxylin and eosin (H&E). Ex vivo foreskin specimens after circumcision surgery were treated with a PSL at 1.3, 2.1, and 2.9 mJ fluence for two and 10 passes, followed by H&E staining. Ex vivo skin tissue sections treated with a PSL at 2.9 mJ fluence for 10 passes were also immunostained for Melan-A and CD31.

RESULTS

Intraepidermal vacuoles were observed, along with pigment accumulation and inflammatory cell infiltration in the vacuoles at 24 hours after PSL treatment in the in vivo skin specimens. The vacuoles expanded as the fluence increased. Numerous intraepidermal vacuoles were observed, with dermal hemorrhage and inflammatory cell infiltration upon high-fluence, multi-pass PSL treatment in the in vivo skin specimens. PSL treatment yielded both epidermal and dermal vacuoles in ex vivo skin specimens. Melan-A-positive cells were seen in the cystic wall of vacuoles in the epidermal basal layer, whereas CD31-positive cells were detected in the cystic wall of some dermal vacuoles.

CONCLUSIONS

The fractionated 1064-nm PSL produced epidermal vacuoles and dermal lesions, with histological differences between the in vivo and ex vivo skin specimens. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

Treatment of idiopathic onychodystrophy with a 1064 nm picosecond neodymium-doped:yttrium aluminum garnet laser: A retrospective study

BACKGROUND

Laser treatment has emerged as a novel treatment modality for onychodystrophy. Only a few small series have assessed the efficacy of laser treatment in onychodystrophy, most of which were case reports. The therapeutic effect of the 1064 nm neodymium-doped:yttrium aluminum garnet (Nd:YAG) laser for onychodystrophy has been demonstrated. Recently, the picosecond Nd:YAG (PSNY) laser has been introduced to improve various skin disorders.

AIMS

The aim of this study was to verify the efficacy of a 1064 nm PSNY in management of idiopathic onychodystrophy.

METHODS

We present a case series of dystrophic nails treated with a PSNY for onychodystrophy improvement. Planimetry using ImageJ software was used to calculate lesion reduction and proximal clear nail growth. Clinical improvement was assessed using a 5-point Global Assessment Scale (GAS). Adverse events were also assessed.

RESULTS

Twenty-five patients (11 males and 14 females) with a total of 128 nails (94 finger nails and 34 toe nails) were treated. The mean treatment number was 8.7 ± 6.2, and the mean total duration of treatment was 33.4 ± 34.6 weeks. The average proportion of the lesion area decreased significantly (from 65.9% to 46.6%) after PSNY treatment (P < .001). The mean GAS (3.16 ± 1.18) exhibited fair improvement, and there were no serious adverse events.

CONCLUSION

The 1064 nm PSNY laser can provide fair improvement for onychodystrophy with a good prognosis at least during the follow-up period and optimal cosmetic results in Asian patients.

Clinical improvement of photoaging-associated facial hyperpigmentation in Korean skin with a picosecond 1064-nm neodymium-doped yttrium aluminum garnet laser

Traditional attempts at alleviating photoaging-associated facial pigmentation conditions such as melasma, mottled hyperpigmentation, and post-inflammatory hyperpigmentation have yielded disfiguring cosmetic results. Laser toning using a low-fluence Q-switched 1064-nm neodymium-doped yttrium aluminum garnet (Nd:YAG) laser has been more commonly applied to date. However, the treatment efficacy and safety of this approach have not been widely reported. This study therefore evaluated the efficacy and safety of picosecond 1064-nm Nd:YAG laser application for photoaging-associated facial pigmentation treatment in Korean subjects. Forty-seven Korean subjects with photoaging-associated facial pigmentation underwent picosecond 1064-nm laser application. The clinical improvement of 17 patients was assessed by objective measurements such as melanin and erythema indices. All subjects received six biweekly treatments with the laser in a three-pass fashion delivering approximately 2000 to 2500 shots using a zoom handpiece with a spot size of 7 mm, fluence ranging from 0.4 to 0.7 J/cm², and a repetition rate of 10 Hz. Clinicians evaluated the improvement of pigmentation using the pigmentation area and severity index (PSI), and subjects reported their satisfaction level on a four-point scale. Statistical analyses were performed using the SPSS version 19.0 for Windows software program (IBM Corp., Armonk, NY, USA). Forty-seven subjects (45 females and two males) completed this study with a 12-week follow-up period. The average decrease in PSI value at 12 weeks after treatment was 6.85 ± 6.35 points (p < 0.001). The average decreases in the values of the erythema and melanin indices were 19.41 ± 64.64 points (p = 0.234) and 28.88 ± 32.89 points (p = 0.002). An analysis of 32 subjects' reports (68.1%) suggested good or excellent improvement. No serious adverse effects were observed during treatment or the follow-up period. Picosecond 1064-nm Nd:YAG laser application appears to be safe and effective in improving various photoaging-associated facial pigmentation conditions in Korean skin.

A Systematic Review of Picosecond Laser in Dermatology: Evidence and Recommendations

BACKGROUND AND OBJECTIVES

The use of picosecond laser in dermatology was originally focused on optimizing the removal of unwanted tattoos. Subsequent advances in this technology have broadened its clinical indications to include treatment of benign pigmented lesions, photodamage, melasma, and scar revision. In this systematic review, evidence-based recommendations are developed for the use of picosecond laser in dermatology.

STUDY DESIGN/MATERIALS AND METHODS

A comprehensive search of the English language literature was performed up to and including November 2019. Relevant citations were individually evaluated, synthesized, and categorized based on the Level of Evidence. With the addition of the authors' combined clinical experience, clinical recommendations were developed.

RESULTS

After application of inclusion and exclusion criteria, a total of 77 unique studies were evaluated. Treatment of benign pigmented lesions was associated with level I-IV evidence; rejuvenation was associated with level II evidence; melasma was associated with level II evidence; scar revision was associated with level II-III evidence; tattoo removal was associated with level I evidence.

CONCLUSION

Picosecond laser is a safe and effective treatment modality for an increasing range of dermatologic indications. Further development of this technology is warranted. Lasers Surg. Med. © 2020 Wiley Periodicals, Inc.