Treatment of Hori's Nevus with the Q-Switched Nd:YAG Laser

BACKGROUND: Hori's nevus is an acquired pigmented lesion involving bilateral blue-brown facial macules. There has been a dearth of reported treatment modalities for this condition. OBJECTIVE: The purpose of this study was to evaluate the efficacy of the Q-switched Nd:YAG laser for the treatment of Hori's nevus. METHODS: The Q-switched Nd:YAG laser was used to treat Hori's nevus in 66 Asian patients. Patients were treated up to seven times. The follow-up time after the final treatment ranged from 3 to 44 months. RESULTS: Twenty six percent of patients showed good to excellent clearing after one to two treatments. Fifty percent of patients who underwent more than two treatments received good to excellent results. CONCLUSION: The Q-switched Nd:YAG laser can be used to treat Hori's nevus. Results are not as good as those seen with nevus of Ota.     

An In Vivo Trial Comparing the Clinical Efficacy and Complications of Q-Switched 755 nm Alexandrite and Q-Switched 1064 nm Nd:YAG Lasers in the Treatment of Nevus of Ota

BACKGROUND: Q-switched 755 nm alexandrite (QS alex) and Q-switched 1064 nm Nd:YAG lasers are effective in the treatment of nevus of Ota. Our previous in vivo study indicated that patients better tolerate QS alex than QS 1064 nm Nd:YAG laser. However, in terms of clinical efficacy and long-term complications, the study did not indicate which laser is superior. Although both machines may appear to be similar in effectiveness, the low number of treatment sessions may contribute to this apparent lack of difference. OBJECTIVE: The aim of this study was to compare the clinical efficacy and complications of QS 755 nm alex and QS 1064 nm Nd:YAG lasers in the treatment of nevus of Ota after three or more treatment sessions. METHOD: Forty patients were recruited for this study and all had received three or more laser treatment sessions with an interval of at least 2 months between each. Half of the lesion was treated with QS alex and the other half with QS 1064 nm Nd:YAG laser. The degree of lightening was assessed subjectively by the patient using a visual analog scale and objectively by two independent clinicians. Patients were called back to be examined for evidence of complications. RESULTS: In terms of subjective degree of lightening, QS 1064 nm Nd:YAG laser was found to be significantly more efficacious than QS alex (P = 0.018). Both clinicians also found QS 1064 nm Nd:YAG laser to be more effective, but statistical significance was only detected in one, not both of their scores (P = 0.005 and 0.414 for observers 1 and 2, respectively). More patients that received QS Alex developed complications (4 for QS alex and 2 for QS Nd:YAG), but the difference was not statistically significant. CONCLUSION: QS 1064 nm Nd:YAG laser appears to be more effective than QS alex in the lightening of nevus of Ota after three or more laser treatment sessions. However, the majority (55%) of the patients reported no differences in results between the two lasers, and only one of the two observers noted statistically significant improvement of QS 1064 nm Nd:YAG over QS alex.     

A Retrospective Analysis of Complications in the Treatment of Nevus of Ota with the Q-Switched Alexandrite and Q-Switched Nd:YAG Lasers

BACKGROUND: Studies on the use of Q-switched alexandrite (QS alex) and QS Nd:YAG lasers in the treatment of nevus of Ota were limited to case reports and small series. There was no study that looked at the complication rate of these systems. OBJECTIVE: To retrospectively study the complication rate of nevus of Ota patients that were treated with QS alex laser, QS Nd:YAG laser, or a combination of both. METHODS: The study was performed in a teaching hospital and a private hospital, where 513 patients with nevus of Ota had been treated since 1993. The 171 patients with 211 treatment sites were evaluated retrospectively following treatment with QS alex laser only (n = 58), QS Nd:YAG laser (n = 105) only, or a combination of both systems (n = 48). Patients were called back to be interviewed and examined by two independent clinicians to look for evidence of complications. RESULTS: Of the treatment sites, 15. 3% had hypopigmentation, 2.9% had hyperpigmentation, and texture changes and scarring were seen in 2.9% and 1.9%, respectively. The combined treatment group was associated with a significantly higher risk of complications. Thirteen patients had recurrence of their nevus after complete or near-complete clearance with laser treatment. CONCLUSION: Hypopigmentation is common after the use of QS laser for lightening of nevus of Ota. This particularly applies when alternate treatment with QS alex and QS Nd:YAG is used. Recurrence is an important issue and must be taken into consideration, especially when children are treated.     

Comparison of the Frequency-Doubled Q-Switched Nd:YAG Laser and 35% Trichloroacetic Acid for the Treatment of Face Lentigines

BACKGROUND: Face lentigines are one of the manifestations of photodamaged skin and often put people in socially embarrassing situations. Several lasers have been used to remove lentigines at vast expense. However, trichloroacetic acid (TCA) is an alternative for treating lentigines that costs much less. OBJECTIVE: To compare the efficacy of the frequency-doubled Q-Switched Nd:YAG laser (532 nm) and 35% TCA for the treatment of face lentigines. METHODS: Twenty patients (Fitzpatrick skin Types III-IV) with a total of 37 lentigines on faces were randomly collected; each lentigo was divided into medial and lateral halves. Frequency-doubled Q-switched Nd:YAG laser (532 nm) and 35% TCA were applied to the medial and lateral halves of each lentigo respectively. The efficacy after 1 treatment was compared after 6 months. RESULTS: The frequency-doubled Q-switched Nd:YAG laser (532 nm) had a better result than that of 35% TCA for the treatment of facial lentigines. CONCLUSION: In order to get a better result after one treatment, the authors suggest the frequency-doubled Q-switched Nd:YAG laser (532 nm) rather than 35% TCA for treating lentigines even though the cost of frequency-doubled Q-switched Nd:YAG laser (532 nm) is greater than that of 35% TCA for both physician and patient.     

An In vivo Trial Comparing the Use of Different Types of 532 nm Nd:YAG Lasers in the Treatment of Facial Lentigines in Oriental Patients

BACKGROUND: Versapulse is a system that consists of four laser modalities and was developed with the aim of increasing cost-effectiveness. However, as these lasers share a common power supply, for the Q-switched (QS) Nd:YAG 532 nm laser a large spot diameter is necessary to lower the fluence to a suitable level. This can increase the risk of hyperpigmentation when used for the treatment of lentigines in dark-skinned patients. OBJECTIVE: The aim of our study was to access the clinical efficacy and the complication rate of the Versapulse QS Nd:YAG 532 nm laser, the Versapulse long-pulsed Nd:YAG 532 nm laser (without the chill tip), and a conventional QS Nd:YAG 532 nm laser in the treatment of lentigines in Chinese patients. METHODS: Thirty-four Chinese patients with lentigines were randomized to receive laser surgery, with one side of the face treated by one laser and the other side treated by a different system. Patients were monitored for 6 weeks to assess the degree of clearing, hyperpigmentation, hypopigmentation, and erythema. Assessments involved patients interviewed using a visual analog questionnaire and two blinded observers who evaluated the pre- and posttreatment clinical photographs. RESULTS: The Versapulse QS Nd:YAG 532 nm laser was associated with a statistically higher risk of complications. The Versapulse long-pulsed Nd:YAG 532 nm laser was compatible with the conventional QS Nd:YAG 532 nm laser in terms of clinical efficacy and complication rates. CONCLUSION: The Versapulse long-pulsed 532 nm laser is more effective and should be used instead of the Versapulse QS Nd:YAG 532 nm laser for the treatment of lentigines in dark-skinned patients.     

Treatment of Pigmented Hypertrophic Scars with the 585 nm Pulsed Dye Laser and the 532 nm Frequency-Doubled Nd:YAG Laser in the Q-Switched and Variable Pulse Modes: A Comparative Study

BACKGROUND: Pigmented hypertrophic scars are a difficult condition to treat. They may result from traumatic injuries or from surgical and cosmetic procedures. The 585 nm flashlamp-pumped pulsed dye laser (FLPDL) has been used to treat this condition, with significant improvement of varying degrees. It remains to be determined whether other laser modalities may have a similar or even greater success in the treatment of pigmented hypertrophic scars. OBJECTIVE: To determine the efficacy of the 532 nm frequency-doubled Nd:YAG laser in the treatment of pigmented hypertrophic scars as compared to the 585 nm FLPDL. METHODS: Six patients with pigmented hypertrophic scars and skin phototypes II-IV were chosen. A scar was selected for treatment in each patient and divided into four equal 2 cm segments. Three segments were each treated with a different laser modality and one was left untreated to serve as the control. A 585 nm FLPDL was used with an energy of 3.5 J, a pulse duration of 450 microsec, and a 10 mm spot size. A 532 nm Q-switched frequency-doubled Nd:YAG laser was set to an energy of 2.8 J, a 10-nsec pulse, and a 3 mm spot size. The same 532 nm laser was set to the variable pulse mode to treat a 2 cm scar segment, with an energy of 9.5 J, a 10-msec pulse, and a 4 mm spot size. An average of 3.3 treatments were performed on each scar segment, at intervals of 4-6 weeks and long-term follow-up at 22 weeks. Treatment outcome was graded by a blind observer using the Vancouver General Hospital (VGH) Burn Scar Assessment Scale. A SigmaStat t-test was used to determine the statistical significance of the values obtained. RESULTS: Treatment of pigmented hypertrophic scars with the 532 nm Q-switched Nd:YAG laser led to a significant improvement of 38% in the VGH scores when compared to baseline (P =.005). The 585 nm FLPDL also had a favorable effect on the scars, with an average improvement of 36.1% in the VGH scores. There was no significant difference noted between the outcome of treatment with either of these two lasers. Treatment with the 532 nm variable pulse Nd:YAG laser led to a 19% improvement in the VGH scores of scars, which did not differ significantly from the 16.1% improvement observed in control scars on the last follow-up visit. No side effects or complications from treatment were noted or reported during the course of the study. At the conclusion of the study, five of six patients chose the segment treated with the 532 nm Q-switched Nd:YAG laser as the best segment overall. CONCLUSION: The 532 nm Q-switched Nd:YAG laser and the 585 nm FLPDL offer comparable favorable results in the treatment of pigmented hypertrophic scars. The 532 nm Q-switched Nd:YAG laser may be preferred by patients particularly distressed by the dark color of their scars.     

Comparison and sequential study of long pulsed Nd:YAG 1,064 nm laser and sclerotherapy in leg telangiectasias treatment

BACKGROUND AND OBJECTIVES: Millisecond pulsed 1,064 nm Nd:YAG lasers have been developed for the treatment of leg telangiectasias. To date there have been very few side by side comparison studies of laser versus the gold standard sclerotherapy in treating small leg veins. This study aims to compare a long pulsed Nd:YAG laser with contact cooling to sclerotherapy for treating small diameter leg telangiectasias by evaluating objective and subjective clinical effects. STUDY DESIGN/PATIENTS AND METHODS: Fourteen patients were selected with leg telangiectasias ranging from 0.5 to 2 mm at four comparable sites. One site was treated with long pulsed Nd:YAG alone, the second received sclerotherapy alone, the third laser then sclerotherapy, and the last one sclerotherapy then laser. The patients were followed up at 3 months after the last treatment. Photographs were taken pre-operatively and at 3 months after the last session. They were used for objective and comparative analysis. Statistical analysis was performed using Friedman's test controlling for subject. RESULTS: Improvement was tabulated from the photographic assessment on an improvement scale from 0 (no change) to 4 (greater than 75% clearing). There were clinical improvements in the laser group than sclerotherapy without statistical significance. Side effects were minimal and included hyperpigmentation. CONCLUSIONS: This pilot study demonstrates that the Smartepil LS long pulse Nd:YAG 1,064 nm laser can yield results similar to sclerotherapy in the treatment of small leg telangiectasias. Combination of both methods could increase response to treatment.     

倍频Nd:YAG 532nm 波长激光治疗皮肤血管异常性疾病的临床应用研究

观察可变脉宽５３２ｎｍ波长激光治疗皮肤血管异常性疾病的效果。用不同脉宽的ＶＰ５３２ｎｍ波长激光结合冷却疗法治疗各种皮肤血管异常性疾病，观察其疗效及并发症。治疗鲜红斑痣、草莓样血管瘤、蜘蛛样血管瘤、血管痣、毛细血管扩张等皮肤血管异常性疾病共１３８例，均取得了满意的疗效，较传统的方法相比，疗效更为明显。可变脉宽５３２ｎｍ波长激光治疗皮肤血管异常性疾病效果可靠，治疗时辅以冷却治疗对防止局部过度损伤及术后色素沉着均有重要意义     

Using a Side Effect to Therapeutic Advantage: The Darkening of Red Eyebrow Tattoo Pigment Following Q-Switched Laser Treatment

BACKGROUND: Q-switched lasers are commonly used to achieve tattoo removal, utilizing the principle of selective photothermolysis. However, certain tattoo pigments may darken following laser pulsing. OBJECTIVE: To determine whether this side effect can be used to therapeutic advantage in a woman who previously had her eyebrows enhanced with a dark tattoo that spontaneously changed to a reddish hue over time. METHOD: The woman's eyebrows were pulsed with the Q-switched Nd:YAG laser at both 532 nm and 1064 nm. RESULTS: The test areas pulsed with the 1064 nm laser revealed partial clearing. However, 532 nm Q-switched Nd:YAG pulses produced darkening of tattoo pigment both at the test sites and in the subsequent treatment. CONCLUSION: Q-switched lasers can produce darkening of red tattoo pigment. In some cases this side effect can be used to therapeutic advantage.     

A Retrospective Study on the Efficacy and Complications of Q-Switched Alexandrite Laser in the Treatment of Acquired Bilateral Nevus of Ota-Like Macules

BACKGROUND: Acquired bilateral nevus of Ota-like macules (ABNOM), or Hori's macules, is a common Asian condition that is characterized by bluish hyperpigmentation in the bilateral malar regions. Unlike nevus of Ota, ABNOM is an acquired condition that often develops after 20 years of age and involves both sides of the face, but there is no mucosal involvement. Recently Q-switched (QS) 1064 nm Nd:YAG lasers have been effective in clearing this condition. The effectiveness of QS alexandrite lasers has not yet been studied. OBJECTIVE: To retrospectively assess the efficacy and complications of QS alexandrite lasers in the treatment of ABNOM. METHODS: Thirty-two Chinese women with ABNOM ranging in age from 28 to 66 years were involved in the study. All underwent QS alexandrite laser treatment (755 nm, spot size 3 mm, 8 J/cm(2)). Topical hydroquinone and tretinoin cream were given to those with hyperpigmentation after the laser surgery. Clinical photographs were taken before and after laser surgery and assessed by two independent observers. The degree of clearing was scored and complications, including hypopigmentation, hyperpigmentation, scarring, and erythema, were assessed. RESULTS: The mean number of treatment sessions was 7 (range 2-11) and the mean treatment interval was 33 days. Both observers identified more than 80% of the patients as having more than a 50% degree of clearing, and complete clearance was seen in more than 28% of patients. Although most patients had postlaser hyperpigmentation and were on depigmentary regimes, the hyperpigmentation was seen in only 12.5% of the patients during photographic evaluation. Hypopigmentation was seen in 50% of patients and erythema in 41%. CONCLUSION: QS alexandrite appears to be effective in the treatment of ABNOM. Postoperative pigmentary changes were frequent and the use of topical depigmentary agents was necessary to achieve a satisfactory result. Transient hypopigmentation risk was high, affecting up to 50% of the patients. Further study is warranted to compare the efficacy and complications of different laser systems in the treatment of this condition.     

Clinical evaluation of enhanced nonablative skin rejuvenation using a combination of a 532 and a 1,064 nm laser

BACKGROUND AND OBJECTIVES: Improvements in the physical signs of photoaging can be achieved by non-invasive laser resurfacing procedures. To evaluate the effectiveness and safety of the Nd:YAG 1,064 nm and KTP 532 nm lasers for non-invasive skin rejuvenation. STUDY DESIGN/PATIENTS AND METHODS: Subjects requesting non-invasive skin rejuvenation underwent two treatments with the 532 nm laser to one side of the face and with both lasers to the other side, followed by three treatments with the 1,064 nm laser to both sides. Skin characteristics were evaluated before, during, and up to 4 months after treatment. RESULTS: A >25% improvement in overall skin condition was observed for >30% of subjects at the 1 month follow-up and >40% of subjects at the 4 month follow-up. The greatest improvements were observed for visual dryness, roughness, and uneven pigmentation. No adverse events were reported. There was a trend for greater improvement in patients who received more 1,064 nm treatments but this was not statistically significant. CONCLUSIONS: The 532 nm KTP and 1,064 nm Nd: YAG lasers can be effectively and safely used for non-invasive skin rejuvenation.     

Comparative Evaluation of Long-Pulse Alexandrite and Long-Pulse Nd:YAG Laser Systems Used Individually and in Combination for Axillary Hair Removal

BACKGROUND The 755-nm alexandrite and the 1,064-nm Nd:YAG lasers are both utilized for hair removal. Advances in laser technology have led to the development of dual-wavelength treatment for increased efficacy.
OBJECTIVE The objective was to evaluate the safety and efficacy of combining 755- and 1,064-nm wavelengths for axillary hair removal.
METHODS Twenty patients received three treatments at 4- to 6-week intervals in four axillary quadrants. The left upper axilla was treated with the alexandrite laser, the left lower axilla with the Nd:YAG laser, the right upper axilla with combination alexandrite and Nd:YAG laser, and the right lower quadrant with the diode laser. At 1- and 2-month follow-up visits, subjects completed questionnaires and were assessed for percentage of hair reduction.
RESULTS Eighteen subjects completed the study. The greatest reduction was seen with the alexandrite laser at 70.3% and combination of alexandrite and Nd:YAG laser at 67.1%. The diode laser was less efficacious at 59.7% and the Nd:YAG laser had the least improvement with 47.4% reduction. Subjects found the alexandrite and diode lasers to be the most tolerable and the Nd:YAG and combination treatment to be the most painful.
CONCLUSION Combination treatment of alexandrite and Nd:YAG lasers provides no added benefit over the alexandrite laser alone.     

In vivo trial comparing patients' tolerance of Q-switched Alexandrite (QS Alex) and Q-switched neodymium:yttrium-aluminum-garnet (QS Nd:YAG) lasers in the treatment of nevus of Ota

BACKGROUND AND OBJECTIVES: Different types of Q-switched lasers have been found to be effective in the treatment of nevus of Ota. However, a clinical trial involving in vivo comparison of the use of different laser systems has not been performed. The aim of the present study was to compare the patient tolerance of Q-switched Alexandrite (QS Alex) and Q-switched neodymium:yttrium-aluminum-garnet (QS Nd:YAG) lasers in the treatment of nevus of Ota. STUDY DESIGN/MATERIALS AND METHODS: Thirty-three patients (11 male, 22 female) were recruited for this study, and 45 treatment sessions were performed. Half of each lesion was treated with QS Alex and the other half with QS Nd:YAG laser. Patients were interviewed with a visual analog scale questionnaire immediately after treatment and 1 week later. Questions included the degree of pain, swelling, and bleeding. RESULTS: The immediate pain after treatment was more severe for QS Alex than for QS Nd:YAG laser. However, 1 week after laser therapy, most patients found QS Alex to be superior. CONCLUSION: Patients tolerate QS-Alex better than QS Nd:YAG. This finding is important because patients with nevus of Ota are often children, and multiple laser sessions are necessary for complete resolution of the lesion.     

A novel dual‐wavelength,Nd:YAG,picosecond‐domain laser safely and effectively removes multicolor tattoos

Background and Objectives

Although nanosecond‐domain lasers have been the mainstay of laser tattoo removal for decades, recent disruptive innovations in laser design have introduced a new class of commercial Q‐switched lasers that generate picosecond‐domain pulses.

Study

A picosecond‐domain, Nd:YAG laser with a KTP frequency‐doubling crystal was used to treat 31 decorative tattoos in 21 subjects. Safety and effectiveness were determined by blinded evaluation of digital images in this prospective clinical study.

Results

The average clearance overall as evaluated by blinded observers evaluating randomized digital photographs was 79 ± 0.9% (mean ± sem) after an average of 6.5 treatments. Of the 31 tattoos completing treatment, 6 had evidence of mild hyper‐ or hypo‐pigmentation by evaluation of photographs.

Conclusion

The 350 picosecond, 532 nm, and 450 picosecond 1,064 nm Nd:YAG laser is safe and effective for removing decorative tattoos. Lasers Surg. Med. 47:542–548, 2015. © 2015 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.     

Hair Removal Using Topical Suspension-Assisted Q-Switched Nd:YAG and Long-Pulsed Alexandrite Lasers: A Comparative Study

Background. The use of lasers for removal of unwanted hair has been shown to be effective in temporarily controlling hair growth. Several lasers are currently utilized for this purpose.
Objective. This study evaluates the short-term effectiveness and discomfort levels of the long-pulsed alexandrite laser and the topical suspension-assisted Q-switched Nd:YAG laser in a side-by-side comparison.
Methods. Fifteen subjects were treated in the bilateral hair-bearing axilla, using one treatment with the alexandrite laser for the right and two treatments with the topical suspension-assisted Nd:YAG laser for the left. Reduction in hair regrowth was measured at 2 and 3 months following the first treatment by comparing the terminal hair count to the baseline values. Patients rated their pain on a scale of 0–10 immediately following the first treatment at each site.
Results. The mean percentage reduction in hair regrowth 2 months following alexandrite laser treatment was 55% and 73% for the Nd:YAG laser-treated regions. After 3 months, alexandrite laser-treated patients showed a reduction of 19%, while Nd:YAG laser-treated patients showed a 27% reduction. Patients reported average pain values of 8 and 4 for the long-pulsed alexandrite and Nd:YAG laser sites, respectively. All differences were significant.
Conclusion. While the design of this study makes it difficult to compare the relative effectiveness of the lasers, both systems evaluated were shown to delay hair growth and provide patients with a satisfactory treatment.     

调Q开关Nd:YAG激光治疗色素性皮肤病1051例临床观察

目的探讨调Q开关Nd∶YAG激光治疗色素性皮肤病的疗效和不良反应。方法回顾性分析调Q开关Nd∶YAG激光治疗1 051例色素性皮肤病的临床疗效和不良反应,其中太田痣365例、雀斑103例、咖啡斑106例、褐青色痣43例、雀斑样痣37例、文身128例、外伤性文身57例、斑痣96例、脂溢性角化116例。结果太田痣、雀斑、脂溢性角化疗效最好,总有效率均为100%,褐青色痣、文身和外伤性文身亦有上佳疗效,总有效率均在90%以上。咖啡斑、雀斑样痣、斑痣亦有不同程度疗效,总有效率分别为63.2%、51.4%、45.8%。结论调Q开关Nd∶YAG激光治疗色素性皮肤病安全性高,对绝大多数太田痣、雀斑、脂溢性角化、褐青色痣、文身、外伤性纹身可达到治愈的效果,对咖啡斑、雀斑样痣、斑痣亦有一定程度的疗效。     

Treatment of Facial Telangiectasia Using a Dual-Wavelength Laser System (595 and 1,064 nm): A Randomized Controlled Trial with Blinded Response Evaluation

BACKGROUND AND OBJECTIVE Pulsed dye (PDL) 595- and 1,064-nm Nd:YAG lasers are used for the treatment of vascular lesions. PDL-heated blood exhibits increased absorption of radiation at 1,064 nm, suggesting that the use of combined sequential dual wavelengths may offer benefits over single-wavelength treatments. This study compares the treatment efficacy of combined sequential dual-wavelength versus single delivery of 595-nm PDL or 1,064-nm Nd:YAG wavelengths in facial telangiectasia in a split face study design using subpurpuric parameters.
MATERIALS AND METHODS Twenty patients were studied using the sequential delivery of PDL and Nd:YAG wavelengths on one side of the nose. The other side received either PDL or Nd:YAG treatment. Vessels (<0.6 mm in diameter) were treated with a 7-mm spot size at 10 J/cm², 10 ms with the PDL, followed by the Nd:YAG at 70 J/cm², 15 ms with a multiplex interpulse delay of 100 ms. Subjects received a single treatment, and results were evaluated after 4-week follow-up. Improvement was determined by blinded assessment of photographs taken before and after final evaluation.
RESULTS The efficacy of the dual-wavelength laser treatment when compared to Nd:YAG or PDL laser alone was significantly more evident than either single-wavelength treatment ( p <.05). There was no statistically significant difference in efficacy between the single-wavelength treatment groups.
CONCLUSION The sequential delivery of 595- and 1,064-nm-wavelength radiation with an interpulse delay suggests that the synergistic approach to laser therapy for facial telangiectasia is a superior method compared to standard single wavelength therapy.     

Histologic Evaluation of a Q-Switched Nd:YAG Laser in the Nonablative Treatment of Wrinkles

BACKGROUND: A variety of nonablative dermal remodeling techniques are currently available. The Q-switched Nd:YAG laser, in addition to its role in tattoo removal, hair removal, and vascular and pigmented lesion treatment, may also play a role in dermal remodeling for the treatment of wrinkles. The histologic changes seen in human skin after Q-switched Nd:YAG laser exposure have yet to be evaluated. OBJECTIVE: To study histologic changes after the use of a Q-switched Nd:YAG laser in the nonablative treatment of photoaged skin. METHODS: Sun-damaged infrauricular skin from six female subjects was exposed to a Q-switched Nd:YAG laser at fluences of 7 J/cm2 with two laser passes. Histologic examinations were performed before laser treatment and 3 months later. RESULTS: Biopsy specimens showed slight fibrosis in the superficial papillary dermis with unremarkable epidermal changes. CONCLUSION: The Q-switched Nd:YAG laser produced morphologic changes similar to, but lesser in degree, than those seen with both CO2 and Er:YAG laser resurfacing.     

A split-face,evaluator-blind randomized study on the early effects of Q-switched Nd:YAG laser plus Er:YAG micropeel (combined therapy) versus Q-switched Nd:YAG alone in light solar lentigines in Asians

Solar lentigines are a common sign of aging in Asians, who often asked for treatment. Various lasers, including Q-switched Nd:YAG and Er:YAG, have been adopted, but the results are not always satisfactory, especially for those who are relatively light in color. Our objective was to compare the early effects as well as side effects of Q-switched Nd:YAG laser plus Er:YAG micropeel (combined therapy) with those of Q-switched Nd:YAG laser (QSNY) alone in light solar lentigines in Asians. This was a split-face, evaluator-blind, randomized controlled study. A single session of treatment was performed on Asian patients with light facial lentigines. A combined treatment with QSNY and Er:YAG micropeel was allocated to one half of the face, and QSNY alone to the other half. The response to therapy was evaluated by two independent dermatologists, with standardized photographs taken 2 weeks and 1 month after the laser treatment. Patients’ satisfaction and preference in treatment were also assessed. Fifteen patients completed the study and were analyzed. Overall, a reduction in pigment was observed with both treatment arms during the study period. The degree of pigment reduction following combined therapy and QSNY alone was similar at 2 weeks’ follow-up (P?=?0.433). However, due to the higher incidence of postinflammatory hyperpigmentation (PIH) with combined therapy (73.3 vs 40 %), the degree of pigment reduction in the combined side of the face was found significantly lower than that of the QSNY-alone side at 1-month follow-up (P?=?0.014). Although our study results show that both combined therapy and QSNY alone are capable of reducing pigmentation, QSNY alone is considered to have more favorable qualities than combined treatment for light solar lentigines in Asians.     

The effects of laser irradiation on <Emphasis Type="Italic">Trichophyton rubrum</Emphasis> growth

The effects of various laser wavelengths and fluences on the fungal isolate, Trichophyton rubrum, were examined in vitro. Standard-size isolates of T. rubrum were irradiated by using various laser systems. Colony areas were compared for growth inhibition on days 1, 3, and 6 after laser irradiation. Statistically significant growth inhibition of T. rubrum was detected in colonies treated with the 1,064-nm Q-switched Nd:YAG laser at 4 and 8 J/cm² and 532-nm Q-switched Nd:YAG laser at 8 J/cm². Q-switched Nd:YAG laser at 532- and 1,064-nm wavelengths produced significant inhibitory effect upon the fungal isolate T. rubrum in this in vitro study. However, more in vitro and in vivo studies are necessary to investigate if lasers would have a potential use in the treatment of fungal infections of skin and its adnexa.