Clinical application of lasers in Asians

Wavelength-dependent threshold fluences for melanosome disruption to evaluate the treatment of pigmented lesions with 532-, 730-, 755-, 785-, and 1064-nm picosecond lasers

BACKGROUND AND OBJECTIVES

A threshold fluence for melanosome disruption has the potential to provide a robust numerical indicator for establishing clinical endpoints for pigmented lesion treatment using a picosecond laser. Although the thresholds for a 755-nm picosecond laser were previously reported, the wavelength dependence has not been investigated. In this study, wavelength-dependent threshold fluences for melanosome disruption were determined. Using a mathematical model based on the thresholds, irradiation parameters for 532-, 730-, 755-, 785-, and 1064-nm picosecond laser treatments were evaluated quantitatively.

STUDY DESIGN/MATERIALS AND METHODS

A suspension of melanosomes extracted from porcine eyes was irradiated using picosecond lasers with varying fluence. The mean particle size of the irradiated melanosomes was measured by dynamic light scattering, and their disruption was observed by scanning electron microscopy to determine the disruption thresholds. A mathematical model was developed, combined with the threshold obtained and Monte Carlo light transport to calculate irradiation parameters required to disrupt melanosomes within the skin tissue.

RESULTS

The threshold fluences were determined to be 0.95, 2.25, 2.75, and 6.50 J/cm² for 532-, 730-, 785-, and 1064-nm picosecond lasers, respectively. The numerical results quantitatively revealed the relationship between irradiation wavelength, incident fluence, and spot size required to disrupt melanosomes distributed at different depths in the skin tissue. The calculated irradiation parameters were consistent with clinical parameters that showed high efficacy with a low incidence of complications.

CONCLUSION

The wavelength-dependent thresholds for melanosome disruption were determined. The results of the evaluation of irradiation parameters from the threshold-based analysis provided numerical indicators for setting the clinical endpoints for 532-, 730-, 755-, 785-, and 1064-nm picosecond lasers.

Photoprotection in skin of color

As populations in many parts of the world are projected to become more racially diverse over the coming decades, we must better understand the unique characteristics of the skin of populations with skin of color (SOC). This review aims to highlight important physiologic and clinical considerations of photoprotection in SOC. Ultraviolet radiation and visible light affect dark and light skin differently. SOC populations have historically not been informed on photoprotection to the same degree as their light skinned counterparts. This has exacerbated dermatologic conditions in which SOC populations are disproportionately affected, such as hyperpigmentary disorders. Patients should be encouraged to utilize multiple methods of photoprotection, ranging from avoidance of sunlight during peak intensity hours, seeking shade, wearing sun-protective clothing and wide-brimmed hat, and applying sunscreen. Ideal sunscreens for SOC populations include those with UVA-PF/SPF ratios ≥ 2/3 and tinted sunscreens to protect against VL. Although there have been increased efforts recently, more research into photoprotection for SOC and targeted public education are required to disseminate photoprotection resources that are patient-centered and evidence-based.

The efficacy of intense pulsed light for Becker's nevus: A retrospective analysis of 45 cases

BACKGROUND

Becker's nevus is a common skin disorder. Lasers and light instruments are the major modalities for the treatment of Becker's nevus, but the outcomes were mixed.

OBJECTIVE

To evaluate the efficacy of the intense pulsed light for Becker's nevus in a large Chinese cohort.

METHODS

We retrospectively analyzed the efficacy of the intense pulsed light for Becker's nevus in a single center.

RESULTS

A total of 45 patients, including 26 males and 19 females (male to female ratio = 1.4), aged 5-42 years, were included in this analysis. Twenty-seven patients (60%) were with hypertrichosis. Treatments with intense pulsed light resulted in over 75% improvements in pigmentation and hair density in 1 and 2 cases, respectively. One patient displayed 51%-75% reductions in hair density. The rest displayed ≤50% improvements in pigmentation and hair density. Recurrence occurred in all cases within 6 months after the last treatment. Adverse reactions were temporary and mild hypopigmentation, hyperpigmentation, hypertrophic scar, pain, and erythema.

CONCLUSION

Intense pulsed light does not exhibit long-term benefits for Becker's nevus. Further studies in the large cohort are still required to validate the present results. Moreover, whether changes in the treatment parameters can improve the efficacy of intense pulsed light remains to be explored.

Histology of ex vivo skin after treatment with fractionated picosecond Nd:YAG laser in high and low-energy settings

Background: The fractionated picosecond laser produces microscopic lesions in the epidermis and dermis, which are known as laser-induced optical breakdown (LIOB) and intra-dermal laser-induced cavitation (LIC). There have been multiple histological reports on these phenomena, although some have been challenged on the grounds of similarity to artifacts. Asian skins, with a higher melanin content, may react differently to this treatment, and present literature is also lacking in this area.Purpose: To observe and report the histological effect of different energy levels and parameters of the fractional 532 nm/1064 nm picosecond laser on Asian skin ex vivo.Methods: Six skin samples were taken from clinically normal-looking perilesional areas and treated with different energy levels and parameters of the fractional 532 nm/1064 nm picosecond laser. The specimens were then sent to the lab for H&E staining, and the slides were reviewed by a dermatopathologist.Results: Superficial, intra-epidermal LIOBs were seen in skin treating at higher laser energies; deep, intra-dermal LICs were seen in skin treated at lower energies. Lesion sizes and depths were consistent with previously reported values on Caucasian skins, and lesions were spaced in 600-μm intervals or its multiple.Conclusions: The histological findings are consistent with results from other ethnicities, and the spacing of lesions is a strong indication of their validity as LIOBs or LICs.

Prospective Comparison Study of 532/1064 nm Picosecond Laser vs 532/1064 nm Nanosecond Laser in the Treatment of Professional Tattoos in Asians

Background and Aims

Although, the pulse width should be shorter than the thermal relaxation time of the target, nanosecond laser pulses are not short enough for tattoo removal. Complications are common, such as hyper or hypopigmentation, textural changes, and scarring. Moreover, patients with darker skin types are at a higher risk of complications from tattoo removal using these lasers. Picosecond lasers were developed to overcome the limitation of nanosecond lasers. We did a comparison study of a 532/1064 nm picosecond laser vs a 532/1064 nm nanosecond laser to evaluate the clinical efficacy and complications of multi-color tattoos in Asians.

Materials and methods

Eleven Asian patients with 37 professional tattoos were enrolled in the study. Each patient was treated with a 532/1064 nm nanosecond laser and a 532/1064 nm picosecond laser. The spot size that was used with each laser was 3 mm. Four treatments were performed, with four week intervals between each treatment. Patients were examined a week after the first treatment and 3 months after the last treatment.

Results and Conclusions

All patients tolerated the treatments well. The efficacy of the 1064 nm picosecond laser for black tattoos is significantly better than the other studied lasers. The efficacy of the 532 nm picosecond laser is significantly better than the other studied lasers for red tattoos. The efficacy of the 532 nm picosecond laser is significantly better than the 532 nm nanosecond laser and better than the 1064 nm picosecond laser for green tattoos. Mild to moderate post-inflammatory hyperpigmentation was observed in 35.1%, 24.3% 27.0%, and 21.6% of the tattoos treated with the 532 nm nanosecond laser, the 532 nm picosecond laser, the 1064 nm nanosecond laser, and the 1064 nm pico-second laser, respectively. Paradoxical darkening (5.4%) was observed equally with each type of laser. There was no scar formation in any of the tattoos treated. The 532/1064 nm picosecond laser is more effective than the 532/1064 nm nanosecond laser in the treatment of multi-color tattoos in Asians. The 532 nm picosecond laser is more effective than 1064 nm picosecond laser in every tattoo color, with the exception of black. Paradoxical darkening was observed, even the use of picosecond lasers.

Meeting the Challenges of Acne Treatment in Asian Patients: A Review of the Role of Dermocosmetics as Adjunctive Therapy

Conventional acne treatment presents several challenges such as intolerable side effects and antibiotic resistance. Dermocosmetic products may be used to reduce these unwanted effects. Dermocosmetics include skin cleansers, topical sebum-controllers, skin antimicrobial/anti-inflammatory agents, moisturizers, sunscreens, and camouflage products. Appropriate use of these products may help augment the benefit of acne treatment, minimize side effects, and reduce the need for topical antibiotics. In Asia, there is currently limited scientific data on the application and recommendations for dermocosmetic use in acne vulgaris (AV). This article reviews the evidence on dermocosmetics for AV and provides practice recommendations as discussed during the 4^th Asia-Pacific Acne Leaders' Summit held in Bangkok, Thailand, on 7 and 8 February 2015. Through a premeeting survey, a series of plenary lectures, a stepwise program of discussion sessions, and Medline article review, the Expert Panel set forth relevant recommendations on the role of dermocosmetics as adjunct for treating AV in Asian patients.

Theoretical review of the treatment of pigmented lesions in Asian skin

Asian skin has a higher epidermal melanin content, making it more likely to develop adverse pigmentary reactions following laser surgery. The nanosecond lasers are the gold standard for the treatment of pigmented lesions, but the risk of complications, such as post-inflammatory hyperpigmentation, is increased in dark-skinned patients. Intense Pulsed Light (IPL) or long-pulsed lasers are available for treating superficial pigmented lesions, and fewer complications are seen when using these devices compared to the nanosecond lasers. Nanosecond lasers are essential in the treatment of dermal melanosis. Recently, picosecond lasers have been investigated. Picosecond lasers will also play an important role in the treatment of pigmented lesions.

Efficacy and Safety of 10,600-nm Carbon Dioxide Fractional Laser on Facial Skin with Previous Volume Injections

Background:

Fractionated carbon dioxide (CO₂) lasers are a new treatment modality for skin resurfacing. The cosmetic rejuvenation market abounds with various injectable devices (poly-L-lactic acid, polymethyl-methacrylate, collagens, hyaluronic acids, silicone). The objective of this study is to examine the efficacy and safety of 10,600-nm CO₂ fractional laser on facial skin with previous volume injections.

Materials and Methods:

This is a retrospective study including 14 patients treated with fractional CO₂ laser and who have had previous facial volume restoration. The indication for the laser therapy, the age of the patients, previous facial volume restoration, and side effects were all recorded from their medical files. Objective assessments were made through clinical physician global assessment records and improvement scores records. Patients’ satisfaction rates were also recorded.

Results:

Review of medical records of the 14 patients show that five patients had polylactic acid injection prior to the laser session. Eight patients had hyaluronic acid injection prior to the laser session. Two patients had fat injection, two had silicone injection and one patient had facial thread lift. Side effects included pain during the laser treatment, post-treatment scaling, post-treatment erythema, hyperpigmentation which spontaneously resolved within a month. Concerning the previous facial volume restoration, no granulomatous reactions were noted, no facial shape deformation and no asymmetry were encountered whatever the facial volume product was.

Conclusion:

CO₂ fractional laser treatments do not seem to affect facial skin which had previous facial volume restoration with polylactic acid for more than 6 years, hyaluronic acid for more than 0.5 year, silicone for more than 6 years, or fat for more than 1.4 year. Prospective larger studies focusing on many other variables (skin phototype, injected device type) are required to achieve better conclusions.

Evaluation of combined fractional radiofrequency and fractional laser treatment for acne scars in Asians

BACKGROUND AND OBJECTIVES

Fractionated radiofrequency (RF) induces deep dermal heating and leaves the epidermis less affected. We studied the efficacy and safety of bipolar RF and fractional diode laser followed by fractional RF in Asians with acne scars.

MATERIALS AND METHODS

Twenty-four patients (skin types III and IV) with acne scars received up to five treatments of combined fractional 915-nm laser and bipolar RF using a Matrix IR applicator (Syneron Medical Ltd, Yokneam, Israel) with fluence ranging from 50 to 70 J/cm(2) , RF at 70-100 J/cm(3) , double passes followed by full-face bipolar fractional RF treatment using Matrix RF at energy ranging from 50 to 62 mJ/pin, at 4-week intervals. Changes in acne scars, skin texture, pore size, pigmentation irregularity, and complications were assessed up to 3 months post-treatment by standardized photographs obtained with Canfield Visia-CR system®. Subjective improvement and patient satisfaction were assessed by questionnaire.

RESULTS

Twenty patients (age 27.7 ± 8.4 years) completed the study. Modest but statistically significant improvement was noted in acne scars, with the mean grade decreased by 29% (P < 0.001), and 52% were rated with at least moderate objective global improvement at 3 months. Mean pain score was 2.6 on a scale of 0-4. There were also objective improvements in all secondary endpoints. Post-inflammatory hyperpigmentation (PIH) occurred mainly over bony areas in 6.5% of all treatments. Subjective improvement was moderate to significant for 36.8% of patients, and 63% reported being satisfied with the treatment results at 3 months despite considerable pain level.

CONCLUSION

Use of fractional laser with RF followed by fractional RF was shown to be safe and effective for acne scars with modest improvement and low PIH rate comparable to other resurfacing techniques in this Asian case series. Adequate pain control and recduced energy level when treating areas in close proximity to bone are advised. Lasers Surg. Med. 44: 622-630, 2012. © 2012 Wiley Periodicals, Inc.

Efficacy and safety of 1,064 nm Q-switched Nd:YAG laser treatment for removing melanocytic nevi

Background

Until recently, the removal of melanocytic nevi has been performed with a CO₂ laser or Er:YAG laser. These lasers have been useful for removing affected spots. However, enlargement of spots or some sequelae, including depressed or hypertrophic scars, could develop as unwanted results. The Q-switched Nd:YAG laser has been used to remove deep-seated melanocytes, such as Ota nevus or tattoos. However, there have been no previous experiments performed to test the efficacy and safety of this laser treatment for melanocytic nevi.

Objective

The objective of this study was to investigate the efficacy and safety of the 1,064 nm Q-switched Nd:YAG laser for removing melanocytic nevi, including congenital nevomelanocytic and acquired nevomelanocytic nevi.

Methods

Two thousand and sixty four Korean patients with small melanocytic nevi were treated with a Q-switched Nd:YAG laser from 2005 to 2009. High-resolution photographs were taken in identical lighting and positions before and after the six weeks of treatment to observe the procedural efficacy.

Results

About 70% of the nevi treated using a 1,064 nm Q-switched Nd:YAG laser were completely removed after one session. The other 30% were completely treated within three sessions. The appearance of sequelae such as hollow scars noticeably decreased compared to the results seen in CO₂ or Er:YAG laser treatments.

Conclusion

Use of the 1,064 nm Q-switched Nd:YAG laser is a safe and effective treatment modality for melanocytic nevi.

The fate of long-standing port-wine stain and its surgical management

BACKGROUND

A port-wine stain begins with thin macular lesions and eventually becomes hypertrophic and forms nodules. Although laser therapy for port-wine stain is a safe treatment modality that has been well-established, the long-standing port-wine stain has a tendency to respond less well to laser treatment. The authors performed total surgical resections of long-standing port-wine stain in the facial region, and attempted to clarify the histomorphologic changes.

METHODS

The records of 15 patients with long-standing port-wine stain were reviewed for nodules and associated characteristics. After removal of the vascular lesions, the affected area was reconstructed with a radial forearm free flap or a skin graft depending on cosmetic considerations. All specimens obtained from resection were stained with hematoxylin and eosin and Victoria blue for elastic fibers for histomorphologic analysis. After a mean follow-up period of 12 years, the outcomes of surgical management were assessed.

RESULTS

The nodules developed in 13 patients, and the mean age for nodule onset was 30 years. Victoria blue staining of the nodular lesions showed an intermingling of thick-walled vessels with abundant elastic fibers and thin-walled vessels without elastic fibers, which are findings typical of arteriovenous malformations. After surgical management, most of the outcomes were satisfactory, without complications or recurrence at long-term follow-up.

CONCLUSIONS

A long-standing nodular port-wine stain can convert to a high-flow malformation with an arterial component, and these lesions are different from early-stage port-wine stains. For the treatment of long-standing port-wine stain that is resistant to laser therapy, surgical methods will bring more satisfactory outcomes than traditional laser therapy.

Treatment of mesh skin grafted scars using a plasma skin regeneration system

Objectives. Several modalities have been advocated to treat traumatic scars, including surgical techniques and laser resurfacing. Recently, a plasma skin regeneration (PSR) system has been investigated. There are no reports on plasma treatment of mesh skin grafted scars. The objective of our study is to evaluate the effectiveness and complications of plasma treatment of mesh skin grafted scars in Asian patients. Materials and Methods. Four Asian patients with mesh skin grafted scars were enrolled in the study. The plasma treatments were performed at monthly intervals with PSR, using energy settings of 3 to 4 J. Improvement was determined by patient questionnaires and physician evaluation of digital photographs taken prior to treatment and at 3 months post treatment. The patients were also evaluated for any side effects from the treatment. Results. All patients showed more than 50% improvement. The average pain score on a 10-point scale was 6.9 +/− 1.2 SD and all patients tolerated the treatments. Temporary, localized hypopigmentation was observed in two patients. Hyperpigmentation and worsening of scarring were not observed. Conclusions. Plasma treatment is clinically effective and is associated with minimal complications when used to treat mesh skin grafted scars in Asian patients.

Fractional laser photothermolysis for treatment of facial wrinkles in Asians

Purpose

To evaluate the safety and efficacy of fractional photothermolysis (FP) in the treatment of facial wrinkles in Asians.

Methods

A total of 27 Korean patients (Fitzpatrick type III or IV) received 2-3 FP treatment sessions (Sellas; Dinona Inc., Seoul, Korea) spaced two weeks apart. Treatments were performed at settings of 7 to 9 mJ/microthermal treatment zone (MTZ) and a density of 1000 MTZ/cm². Standardized digital photographs were obtained before each treatment and three months after the final treatment. The evaluations of clinical photographs were performed by three physicians blinded to the study subjects using a five-point grading scale. In addition, the patients' perceived degree of improvement was assessed three months after the final treatment using a five-point grading scale. Side effects were monitored at each follow-up visit.

Results

The physicians' assessed degrees of improvement were excellent in three patients (12%), significant in ten (40%), and moderate in seven (28%). The patients' self-assessed degrees of improvement were excellent in five patients (20%), significant in 11 (44%), and moderate in six (24%). Adverse events were limited to transient pain, erythema and edema, except in one case of transient postinflammatory hyperpigmentation.

Conclusions

FP is an effective treatment modality for reducing facial wrinkles with minimal side effects in Asian patients.

A therapeutic strategy based on histological assessment of hyperpigmented skin lesions in Asians

Hyperpigmentation is the most common cosmetic skin complaint in Asians, but there is no standard treatment strategy. The aim of this study was to establish a simple therapeutic strategy based on the histological features of hyperpigmented skin lesions in Asians. Fifty-nine biopsies were analysed from 49 Japanese patients with 17 types of hyperpigmented skin lesions. In 10 patients, skin samples were also taken during a topical bleaching treatment that used tretinoin and hydroquinone. These samples were evaluated after staining with haematoxylin-eosin and Fontana-Masson stains. Our experience of treating a variety of pigmented lesions with aggressive topical bleaching and lasers was reviewed. Hyperpigmented lesions were classified into seven categories based on pathological features, especially on the degree of hyperkeratosis and epidermal melanin deposits, and on the existence of melanin incontinence and the location of dermal melanocytes. Tretinoin and hydroquinone therapy was histologically effective for treating epidermal melanin deposits, but not dermal melanosis or dermal melanocytes. Based on pathological features and our extensive clinical experience with hyperpigmented skin, we propose a therapeutic strategy for treating hyperpigmented skin lesions, which may be particularly useful in Asian populations.

Diagnosis and Treatment of Pigmentary Disorders in Asian Skin

Individuals of Asian heritage are predisposed to congenital and acquired pigmentary disorders. Cosmetic enhancement is frequently the primary treatment goal for these benign lesions. Accurate diagnosis of the nature of the pigmentary disorder is fundamental for administering safe and effective therapy. Before the advent of modern laser technology, such reported treatments as cryotherapy, dermabrasion, chemical peeling, and surgical excision resulted in unpredictable results. This article focuses on the diagnosis of disorders of pigmentation in Asian patients and reviews laser and light treatment modalities.

Analysis of 602 Chinese Cases of Nevus of Ota and the Treatment Results Treated by Q-Switched Alexandrite Laser

BACKGROUND

Nevus of Ota is a congenital or acquired pigmentary disorder of the skin and mucous membranes, which are areas innervated by the first and second branches of the trigeminal nerve. Nevus of Ota is very common in Asia. Nevus of Ota was effectively treated with Q-switched alexandrite (755 nm) laser, but no detailed report existed on many Chinese cases treated with Q-switched alexandrite laser.

OBJECTIVE

The objective was to gauge clinical and treatment data and material statistics for 602 cases of nevus of Ota and analyze its pathogenic mechanism and therapeutic results.

METHODS

A total of 602 cases of clinical data on nevus of Ota were collected by means of clinical registration, photo verification, and telephone inquiry or correspondence.

CONCLUSIONS

There are some differences in sex, age, and local regions in nevus of Ota. Nevus of Ota can combine with other diseases. The treatment of Nevus of Ota by a Q-switched alexandrite laser is safe and effective. Additional treatment will achieve good results. The results correlate to the eyelids and Tanino's classification.

Intense Pulsed Light for the Treatment of Refractory Melasma in Asian Persons

BACKGROUND

Patients with dermal or mixed-type melasmas are often refractory to various treatments. Intense pulsed light has been used to treat melanocytic lesions with promising results.

OBJECTIVE

The purpose of this study was to clarify the effectiveness of intense pulsed light for refractory melasma in Asian persons.

METHODS

Seventeen patients were treated with intense pulsed light, during four sessions at 4-week intervals. The patients were also given 4% hydroquinone cream and broad-spectrum sunscreens to prevent and treat postinflammatory hyperpigmentation. Sixteen patients in the control group were treated with hydroquinone cream and sunscreens. The treatment efficacy was evaluated using reflectance spectrophotometer and patient satisfaction questionnaire.

RESULTS

Patients in the intense pulsed light group achieved an average of 39.8% improvement in relative melanin index, compared to 11.6% improvement in the control group (p<0.05) at Week 16. Six (35%) patients in the intense pulsed light group had more than 50% improvement, compared to two (14%) patients in the control group. Two patients in the intense pulsed light group, however, experienced transient postinflammatory hyperpigmentation, and partial repigmentation was noted 24 weeks after the last treatment session.

CONCLUSION

Intense pulsed light is a safe and effective treatment for refractory melasma in Asian persons, with minimal side effects. Further treatment sessions are required for maintenance therapy.

Combined therapy using Q-switched ruby laser and bleaching treatment with tretinoin and hydroquinone for acquired dermal melanocytosis

BACKGROUND AND OBJECTIVE

Acquired dermal melanocytosis (ADM; acquired bilateral nevus of Ota-like macules) is known for its recalcitrance compared with Nevus of Ota, and we assume that one of the reasons is a higher rate and degree of postinflammatory hyperpigmentation (PIH) seen after laser treatments.

METHODS

Topical bleaching treatment with 0.1% tretinoin aqueous gel and 5% hydroquinone ointment containing 7% lactic acid was initially performed (4 to 6 weeks) to discharge epidermal melanin. Subsequently, Q-switched ruby (QSR) laser was irradiated to eliminate dermal pigmentation. Both steps were repeated two to three times until patient satisfaction was obtained (usually at a 2-month interval for laser sessions). This treatment was performed in 19 patients with ADM. Skin biopsy was performed in six cases at baseline, after the bleaching pretreatment, and at the end of treatment.

RESULTS

All patients showed good to excellent clearing after two to three sessions of QSR laser treatments. The total treatment period ranged from 3 to 13 (mean of 8.3) months. PIH was observed in 10.5% of the cases. Histologically, epidermal hyperpigmentation was observed in all specimens and was dramatically improved by the topical bleaching pretreatment.

CONCLUSION

QSR laser combined with the topical bleaching pretreatment appeared to treat ADM consistently with a low occurrence rate of PIH and lessen the number of laser sessions and total treatment period and may also be applied to any other lesions with both epidermal and dermal pigmentation.

Laser therapy on darker ethnic skin

Like all medical procedures laser therapy comes with inherent risks and complications. Because of the increased risk in epidermal side effects when performing laser therapy on patients with darker skin, a higher level of laser expertise and clinical experience in treating darker ethnic skin is recommended to ensure that patients are treated safely. Test spots should always be done as an aid to selecting safe and efficacious treatment parameters. Because of the limited experience in treating patients with darker skin a conservative approach should always be used. Unfortunately, there are no national policies establishing credentialing requirements for those planning to practice laser surgery. The US Food and Drug Administration are responsible for granting individual laser manufacturers' permission to market their lasers for specific indications. The Food and Drug Administration also recommends operator training to use these lasers, but credentialing is a state function and consequently standards for laser therapy vary greatly from state to state. Until the bar is raised and national credentialing polices on laser therapy are established clinicians must police themselves and fully be aware of their capabilities and limitations to ensure that all patients regardless of skin color or ethnicity receive safe and effective treatments.