Zakia Rahman, M.D., is Clinical Professor, Assistant Chief at the Livermore Division of the PAVAHCS and Director of the Resident Laser and Aesthetic Clinic. Dr. Rahman serves on the American Academy of Dermatology Diversity Committee. She also is member of the Stanford Physician Wellness Committee and the Stanford Medical School Faculty Senate. Her clinical interests include geriatric dermatology, surgical dermatology, lasers, ethnic skin, fillers and neurotoxins for medical and aesthetic indications. Her research interests include lasers for medical and aesthetic indications and ethnic skin.

Clinical Focus

  • Aesthetic Dermatology
  • Laser Dermatology  
  • Skin of Color
  • Procedural Dermatology

Academic Appointments

Administrative Appointments

  • Immediate Past Chair, Stanford School of Medicine Faculty Senate (2022 - 2024)
  • Chair, Stanford School of Medicine Faculty Senate (2020 - 2022)
  • Senate Executive Committee, Stanford School of Medicine Faculty Senate (2018 - Present)
  • Dermatology Departmental Senator, Stanford School of Medicine Faculty Senate (2015 - Present)
  • Dermatology Wellness Director, Stanford WellMD/PhD Wellness Directors Council (2018 - 2023)

Honors & Awards

  • Melanie Grossman Award for Leadership, Mentorship, and Advocacy for Women in Medical Science, American Society for Laser Medicine and Surgery (2023)
  • Presidential Citation for advancement of diversity in the field of Dermatology., American Academy of Dermatology (2017)

Professional Education

  • Internship: Yale New Haven Dept of Internal Medicine (2000) CT
  • Board Recertification, American Board of Dermatology, General Dermatology, Dermatologic Surgery (2013)
  • Board Certification: American Board of Dermatology, Dermatology (2004)
  • Residency: St Lukes-Roosevelt Columbia University (2004) NY
  • Fellowship, St Lukes-Roosevelt Columbia University, Skin of Color (2001)
  • Medical Education: University of Illinois College of Medicine (1998) IL
  • Bachelor of Arts, University of Chicago, Honors in Biological Sciences in 3 years (1994)

2023-24 Courses

All Publications

  • "Filler-Associated Acute Stroke Syndrome": Classification, Predictive Modelling of Hyaluronidase Efficacy, and Updated Case Review on Neurological and Visual Complications. Aesthetic plastic surgery Rahman, E., Philipp-Dormston, W. G., Webb, W. R., Rao, P., Sayed, K., Sharif, A. Q., Yu, N., Ioannidis, S., Tam, E., Rahman, Z., Mosahebi, A., Goodman, G. J. 2024


    The rising use of soft tissue fillers for aesthetic procedures has seen an increase in complications, including vascular occlusions and neurological symptoms that resemble stroke. This study synthesizes information on central nervous system (CNS) complications post-filler injections and evaluates the effectiveness of hyaluronidase (HYAL) treatment.A thorough search of multiple databases, including PubMed, EMBASE, Scopus, Web of Science, Google Scholar, and Cochrane, focused on publications from January 2014 to January 2024. Criteria for inclusion covered reviews and case reports that documented CNS complications related to soft tissue fillers. Advanced statistical and computational techniques, including logistic regression, machine learning, and Bayesian analysis, were utilized to dissect the factors influencing therapeutic outcomes.The analysis integrated findings from 20 reviews and systematic analyses, with 379 cases reported since 2018. Hyaluronic acid (HA) was the most commonly used filler, particularly in nasal region injections. The average age of patients was 38, with a notable increase in case reports in 2020. Initial presentation data revealed that 60.9% of patients experienced no light perception, while ptosis and ophthalmoplegia were present in 54.3 and 42.7% of cases, respectively. The statistical and machine learning analyses did not establish a significant linkage between the HYAL dosage and patient recovery; however, the injection site emerged as a critical determinant.The study concludes that HYAL treatment, while vital for managing complications, varies in effectiveness based on the injection site and the timing of administration. The non-Newtonian characteristics of HA fillers may also affect the incidence of complications. The findings advocate for tailored treatment strategies incorporating individual patient variables, emphasizing prompt and precise intervention to mitigate the adverse effects of soft tissue fillers.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 .

    View details for DOI 10.1007/s00266-024-04202-y

    View details for PubMedID 38971925

    View details for PubMedCentralID 7558437

  • Points to ponder on the role of polynucleotides in regenerative and aesthetic medicine: a systematic review EUROPEAN JOURNAL OF PLASTIC SURGERY Webb, W., Rahman, E., Rao, P., Abu-Farsakh, H., Yu, N., Garcia, P. E., Ioannidis, S., Sayed, K., Tam, E., Philipp-Dormston, W. G., Najlah, M., Rahman, Z., Carruthers, J. A., Mosahebi, A. 2024; 47 (1)
  • Generational Exploration on Aesthetic Medicine Products: Influence of Social Media, Reviews, and Brand Identity-GEMS Bond Survey. Aesthetic plastic surgery Rahman, E., Webb, W. R., Rao, P., Yu, N., Garcia, P. E., Ioannidis, S., Philipp-Dormston, W. G., Sayed, K., Rahman, Z., Mosahebi, A., Carruthers, J. D. 2024


    INTRODUCTION: The study investigates the impact of social media reviews and brand identity on consumer preferences in the non-surgical aesthetics products across different generations. It highlights the evolving landscape of aesthetic medicine and surgery, driven by technological advancements and a cultural shift towards individual well-being. The research aims to explore the interplay between generational preferences, the influence of social media, and the role of brand identity in shaping consumer decisions.METHODS: A cross-sectional study design was employed, with a sample size of > 5000 participants stratified across various generational cohorts. The study utilized an online questionnaire to capture both quantitative and qualitative insights into consumer behaviour, with statistical analysis performed to identify patterns and relationships.RESULTS: Analysis of 5850 responses revealed distinct generational preferences and behaviours. Social media engagement varied significantly across generations, with younger cohorts placing a higher emphasis on online reviews. The study also found that brand identity's influence is diminishing in decision-making processes, with consumers increasingly relying on peer reviews and social media content.CONCLUSION: The findings highlight a pivotal shift in the non-surgical aesthetics consumer market, emphasizing the growing importance of social media and peer reviews over traditional brand identities. Importantly, the study underscores the critical need for integrating patient safety and evidence-based practice within marketing strategies. As consumer preferences evolve towards valuing transparency and authenticity, non-surgical aesthetics providers must prioritize these elements, ensuring that their services are not only appealing but also grounded in safety and scientific validity.LEVEL OF EVIDENCE IV: "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 ."

    View details for DOI 10.1007/s00266-024-04109-8

    View details for PubMedID 38839613

  • Translational Biochemistry of the Skin. Facial plastic surgery clinics of North America Voller, L., Rahman, Z. 2023; 31 (4): 443-452


    Understanding translational biochemistry of the skin is an essential component in mastering non-invasive aesthetic treatments. Collagen is the most abundant protein in the animal kingdom and plays a significant role in maintaining structural function in biologically healthy human skin. Collagen degradation and synthesis occurs throughout human life. Upregulation of collagen synthesis remains the mainstay of non-invasive aesthetic skin treatments. Elastin is a smaller yet significant component in the skin's ability to maintain biologically healthy stretch and recoil. Multi-Omics represents a relatively nascent field in the optimization and development of therapies aimed at the aesthetic improvement of the skin.

    View details for DOI 10.1016/j.fsc.2023.06.009

    View details for PubMedID 37806678

  • 1,550 nm Erbium-Doped and 1,927 nm Thulium Nonablative Fractional Laser System: Best Practices and Treatment Setting Recommendations. Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.] Friedman, P. M., Dover, J. S., Chapas, A., Rahman, Z., Ross, E. V., Kilmer, S. L., Roberts, W. E., Sodha, P., Stimmel, J. B., Moncrief, M. B., Waibel, J. S. 1800


    BACKGROUND: The Fraxel Dual laser system (Solta Medical, Inc., Bothell, WA) contains a 1,550 and 1,927 nm wavelength single handpiece with different indications for each wavelength.OBJECTIVE: To discuss treatment setting recommendations and best practices for select on-label and investigational applications of the 1,550 and 1,927 nm dual laser system.MATERIALS AND METHODS: Eight board-certified dermatologists with 10 or more years of experience with the 1,550 and 1,927 nm laser system completed an online survey about their clinical experience with the system and then participated in a roundtable to share clinical perspectives and best practices for using the laser system.RESULTS: For all Fitzpatrick skin types, treatment recommendations were described for selected approved indications for the 1,550 and 1,927 nm laser system, including both lasers in combination. Treatment recommendations were also reached for investigational applications with the 1,550 nm laser and 1,927 nm laser. Best practices for using the lasers during the treatment session to achieve optimal outcomes and decrease the post-treatment recovery time were compiled.CONCLUSION: The 1,550 and 1,927 nm dual laser system is effective for a wide range of aesthetic and therapeutic applications, on and off the face and across all Fitzpatrick skin types.

    View details for DOI 10.1097/DSS.0000000000003321

    View details for PubMedID 35050945

  • Optimizing Outcomes With the 1550/1927 nm Dual Wavelength Non-Ablative Fractional Laser: Experienced User Recommendations JOURNAL OF DRUGS IN DERMATOLOGY Friedman, P. M., Chapas, A., Kilmer, S. L., Rahman, Z., Roberts, W., Ross, E., Waibel, J. S., Dover, J. S. 2021; 20 (11): 1150-1157


    Fractional laser treatment was introduced in 2004 as a non-invasive technique to treat sun-damaged and aging skin. Since then, numerous ablative and non-ablative photothermolysis technologies and devices have been introduced, increasing the options for clinicians and patients but also increasing the complexity regarding which system to use and the techniques to optimize outcomes. No two devices are the same and the user-manuals preset dosimetry does not address many clinical situations, which can create confusion for new and inexperienced users.An online survey addressing use of a 1550 nm /1927 nm dual wavelength, non-ablative, fractional laser was sent to eight (8) US board certified dermatologists with extensive experience in the use of the device. The survey included 39 questions, addressing experience, best practices and recommendations for use.The survey data suggests that the device can be used to treat patients of all ages and skin types for indications including photoaging and photodamage, periorbital wrinkles, freckles, (ephelides), solar lentigines, poikiloderma, scarring due to acne or surgery. It can be used on both facial and non-facial areas, including neck, chest, hands, arms, abdomen, legs, and buttocks. Unexpected and adverse effects were rarely reported and those that did were mild and transient.This position paper provides practical real-world guidelines resulting from a small survey of experienced users, for new and early uses of the novel 1550 nm /1927 nm dual wavelength, non-ablative, fractional laser. J Drugs Dermatol. 2021;20(11):1150-1157. doi:10.36849/JDD.6181.

    View details for DOI 10.36849/JDD.6181

    View details for Web of Science ID 000721535300001

    View details for PubMedID 34784135

  • Laser-Assisted Delivery of Topical Rapamycin: mTOR Inhibition for Birt-Hogg-Dube Syndrome DERMATOLOGIC SURGERY Kim, D., Wysong, A., Teng, J. M., Rahman, Z. 2019; 45 (12): 1713–15
  • Laser-Assisted Delivery of Topical Rapamycin: mTOR Inhibition for Birt-Hogg-Dube Syndrome. Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.] Kim, D., Wysong, A., Teng, J. M., Rahman, Z. 2019

    View details for PubMedID 30640787

  • A Practical Approach to Chemical Peels: A Review of Fundamentals and Step-by-step Algorithmic Protocol for Treatment. The Journal of clinical and aesthetic dermatology Soleymani, T., Lanoue, J., Rahman, Z. 2018; 11 (8): 21–28


    Background: Chemoexfoliation, also known as chemical peeling, is a method of targeted cutaneous ablation using specific caustic agents that allow for rapid, predictable, and uniform thickness of chemoablation to a desired cutaneous depth, ultimately resulting in an improved appearance of skin. Objective: In this review, we provide an up-to-date analysis of all currently available chemical peels for dermatologic use, as well as a step-by-step instructional protocol for an algorithmic approach to treatment. Methods: A comprehensive search of the Cochrane Library, MEDLINE, and PUBMED databases was performed to identify relevant literature investigating chemical peeling agents. In addition, a search of all commercially available, prescription-based peeling agents was performed to identify all products currently available in the United States market. Results and Conclusion: Chemical peels are the third most commonly performed noninvasive cosmetic procedure in the United States, with over 1,300,000 procedures performed in 2016 alone. There has been a paradigm shift in recent years, with lasers largely supplanting deep peels. Despite this shift, superficial peels have proliferated in both popularity and product diversity. When used for the appropriate indication and with proper technique, nearly all peeling agents have demonstrated excellent clinical efficacy and remain an indispensable cost-effective tool in the dermatologist's aesthetic toolbox.

    View details for PubMedID 30214663

  • Mitigation of epidermal growth factor receptor inhibitor-induced side effects utilizing melanin and vascular-specific lasers: A case report series. Journal of cosmetic and laser therapy Kuo, K. Y., Kwong, B., Rahman, Z. 2017: 1-3


    The advent of targeted chemotherapy has led to the emergence of new dermatologic toxicities. We sought to use lasers and light devices to treat recalcitrant cutaneous adverse effects related to cancer treatment. Three stage III or IV cancer patients with cutaneous complications due to epidermal growth factor receptor (EGFR) inhibitors were treated with melanin and vascular-specific laser and light technologies. Two patients reported reduction in papulopustular eruption following pulse dye laser (PDL) treatment. Two patients noted reduction in hair growth following intense pulsed light (IPL) and/or Alexandrite laser treatments. One patient was treated with both the PDL and IPL and reported improvement of both EGFR-induced hypertrichosis and papulopustular eruption. Laser and light devices targeting melanin and hemoglobin can be utilized to mitigate the cutaneous adverse effects associated with EGFR inhibitors in patients who have failed traditional therapies. This represents a new option for the cancer patient who is suffering from chemotherapy-induced side effects.

    View details for DOI 10.1080/14764172.2017.1299187

    View details for PubMedID 28463045

  • Treatment of Surgical Scars with Laser Therapy CURRENT DERMATOLOGY REPORTS Geraghty, L., Rahman, Z. 2016; 5 (3): 143–49
  • Long-term Efficacy of Topical Fluorouracil Cream, 5%, for Treating Actinic Keratosis A Randomized Clinical Trial JAMA DERMATOLOGY Pomerantz, H., Hogan, D., Eilers, D., Swetter, S. M., Chen, S. C., Jacob, S. E., Warshaw, E. M., Stricklin, G., Dellavalle, R. P., Sidhu-Malik, N., Konnikov, N., Werth, V. P., Keri, J., Lew, R., Weinstock, M. A. 2015; 151 (9): 952-960


    Topical fluorouracil was demonstrated to be effective in reducing the number of actinic keratoses (AKs) for up to 6 months, but no randomized trials studied its long-term efficacy.To evaluate the long-term efficacy of a single course of fluorouracil cream, 5%, for AK treatment.The Veterans Affairs Keratinocyte Carcinoma Chemoprevention (VAKCC) trial was a randomized, double-blinded, placebo-controlled trial with patients from dermatology clinics at 12 VA medical centers recruited from 2009 to 2011 and followed up until 2013. Our study population comprised 932 veterans with 2 or more keratinocyte carcinomas in the 5 years prior to enrollment. The mean follow-up duration was 2.6 years in both treatment and control groups.Participants applied either topical fluorouracil cream, 5% (n = 468), or vehicle control cream (n = 464) to the face and ears twice daily for up to 4 weeks.This study reports on AK counts and treatments, which were secondary outcomes of the VAKCC trial. Actinic keratoses on the face and ears were counted by study dermatologists at enrollment and at study visits every 6 months. The number of spot treatments for AKs on the face and ears at semiannual study visits and in between study visits was recorded.The number of AKs on the face and ears per participant was not different between the fluorouracil and control groups at randomization (11.1 vs 10.6, P > .10). After randomization, the fluorouracil group had fewer AKs compared with the control group at 6 months (3.0 vs 8.1, P < .001) and for the overall study duration (P < .001). The fluorouracil group also had higher complete AK clearance rates (38% vs 17% at 6 months) and fewer spot treatments at 6-month intervals, at study visits, and in between study visits during the trial (P < .01 for all). The fluorouracil group took longer to require the first spot AK treatment (6.2 months) compared with the control group (6.0 months) (hazard ratio, 0.69; 95% CI, 0.60-0.79). The number of hypertrophic AKs was not different between the 2 groups overall (P = .60), although there were fewer hypertrophic AKs in the fluorouracil group at 6 months (0.23 vs 0.41) (P = .05).Our results indicate that a single course of fluorouracil cream, 5%, effectively reduces AK counts and the need for spot treatments for longer than 2 Identifier:NCT00847912.

    View details for DOI 10.1001/jamadermatol.2015.0502

    View details for PubMedID 25950503

  • Rationalizing Outcome Measures in Dermatologic Surgery CURRENT DERMATOLOGY REPORTS Alam, M., Maher, I. A., Sobanko, J. F., Yoo, S. S., Avram, M. M., Gladstone, H. B., Metelitsa, A., Northington, M. E., Rahman, Z., Shin, T. M., Cartee, T. V., IMPROVED Working Grp 2015; 4 (3): 140–46
  • Lack of efficacy with 1064-nm neodymium:yttrium-aluminum-garnet laser for the treatment of onychomycosis: A randomized, controlled trial. Journal of the American Academy of Dermatology Hollmig, S. T., Rahman, Z., Henderson, M. T., Rotatori, R. M., Gladstone, H., Tang, J. Y. 2014; 70 (5): 911-917


    Laser therapies have been Food and Drug Administration approved for temporary nail plate clearance; however, there is minimal evidence of their long-term efficacy.We sought to evaluate the clinical and mycological clearance of toenails treated with 1064-nm neodymium:yttrium-aluminum-garnet laser versus no treatment.This was a randomized, controlled, single-center trial comparing 2 treatments with 1064-nm neodymium:yttrium-aluminum-garnet laser (fluence of 5 J/cm(2), rate of 6 Hz) spaced 2 weeks apart versus no treatment in 27 patients (N = 125 affected nails) with clinical and mycological diagnosis of onychomycosis. At 3 months, patients were assessed with mycological cultures and proximal nail plate measurements. Patients treated with laser were also assessed with proximal nail plate measurements at 12 months.At 3 months, 33% of patients treated with laser achieved a negative mycological culture compared with 20% of the control group (P = .49), and had more proximal nail plate clearance compared with control subjects (0.44 vs 0.15 mm, P = .18), which was not statistically significant. At 12 months, there was no difference in nail plate clearance between laser versus control subjects (0.24 vs 0.15 mm, P = .59).Our study was limited by the small sample size and number of treatments.There was no significant mycological culture or clinical nail plate clearance with 1064-nm neodymium:yttrium-aluminum-garnet laser compared with control.

    View details for DOI 10.1016/j.jaad.2013.12.024

    View details for PubMedID 24641985

  • Treatment of Poikiloderma with Fractional Resurfacing BODY REJUVENATION Rahman, Z., Alam, M., Pongprutthipan, M. 2010: 31–37
  • In vivo confocal imaging of epidermal cell migration and dermal changes post nonablative fractional resurfacing: study of the wound healing process with corroborated histopathologic evidence JOURNAL OF BIOMEDICAL OPTICS Stumpp, O. F., Bedi, V. P., Wyatt, D., Lac, D., Rahman, Z. 2009; 14 (2)


    In vivo wound healing response post nonablative fractional laser treatment is evaluated. Seven healthy subjects receive treatments with a Fraxel re:store laser system on the forearm with pulse energies ranging from 10 to 70 mJ. The treatment sites are imaged at 1-h increments up to 40 h using confocal microscope z-stacks using 10-mum-depth spacing. At least five individual microscopic treatment zones are imaged per subject, time point, and treatment energy. Images are analyzed for tissue structure and morphology to classify each lesion as healed or not healed, depending on epidermal re-epithelialization at each time point and treatment energy. Probit analysis is used to statistically determine the ED(50) and ED(84) probabilities for a positive dose response (healed lesion) as a function of treatment energy. Confocal observations reveal epidermal keratinocyte migration patterns confirmed with histological analysis using hematoxylin and eosin (HE) and lactate dehydrogenase (LDH) staining at 10 mJ at 0, 7, 16, and 24-h post-treatment. Results indicate that more time is required to conclude re-epithelialization with larger lesion sizes (all less than 500 mum) corresponding to higher treatment energies. For the entire pulse energy range tested, epidermal re-epithelialization concludes between 10 to 22-h post-treatment for ED(50) and 13 to 28 h for ED(84).

    View details for DOI 10.1117/1.3103316

    View details for Web of Science ID 000266868500042

    View details for PubMedID 19405748

  • Fractional Deep Dermal Ablation Induces Tissue Tightening LASERS IN SURGERY AND MEDICINE Rahman, Z., MacFalls, H., Jiang, K., Chan, K. F., Kelly, K., Tournas, J., Stumpp, O. F., Bedi, V., Zachary, C. 2009; 41 (2): 78-86


    Due to the significant risk profile associated with traditional ablative resurfacing, a safer and less invasive treatment approach known as fractional deep dermal ablation (FDDA) was recently developed. We report the results of the first clinical investigation of this modality for treatment of photodamaged skin.Twenty-four subjects received treatments on the inner forearm with a prototype fractional CO(2) laser device (Reliant Technologies Inc., Mountain View, CA) at settings of 5-40 mJ/MTZ and 400 MTZ/cm(2). Clinical and histological effects were assessed by study investigators 1 week, 1 month, and 3 months following treatment. Thirty subjects were then enrolled in a multi-center study for treatment of photodamage using the same device. Subjects received 1-2 treatments on the face and neck, with energies ranging from 10 to 40 mJ/MTZ and densities ranging from 400 to 1,200 MTZ/cm(2). Study investigators assessed severity of post-treatment responses during follow-up visits 48 hours, 1 week, 1 month, and 3 months following treatment. Using a standard quartile improvement scale (0-4), subjects and investigators assessed improvement in rhytides, pigmentation, texture, laxity and overall appearance 1 and 3 months post-treatment.Clinical and histologic results demonstrated that fractional delivery of a 10,600 nm CO(2) laser source offers an improved safety profile with respect to traditional ablative resurfacing, while still effectively resurfacing epidermal and dermal tissue. Forearm and facial treatments were well-tolerated with no serious adverse events observed. Eighty-three percent of subjects exhibited moderate or better overall improvement (50-100%), according to study investigator quartile scoring.FDDA treatment is a safe and promising new approach for resurfacing of epidermal and deep dermal tissue targets.

    View details for DOI 10.1002/lsm.20715

    View details for PubMedID 19226572

  • Fractional resurfacing for the treatment of hypopigmented scars: A pilot study DERMATOLOGIC SURGERY Glaich, A. S., Rahman, Z., Goldberg, L. H., Friedman, P. M. 2007; 33 (3): 289-293


    Treatments for hypopigmented scars have shown limited efficacy and variable safety profiles. OBJECTIVE This study evaluated the safety and efficacy of fractional resurfacing (1,550-nm Fraxel SR laser, Reliant Technologies, Mountain View, CA) for the treatment of hypopigmented scars on the face in seven patients.Seven patients with hypopigmented scars on the face received between two and four successive treatments at 4-week intervals with the 1,550-nm Fraxel SR laser. Energy settings ranged from 7 to 20 mJ and a total density of 1,000 to 2,500 microthermal zones per square centimeter. Digital photographs were taken before each treatment and at 4 weeks after the last treatment. Independent physician clinical assessments were performed.Independent physician clinical assessment 4 weeks after the final Fraxel SR laser treatment revealed improvements of 51% to 75% in hypopigmentation in six of seven patients. One patient had only 26% to 50% improvement in hypopigmentation. Additionally, clinical improvements were noted in the overall texture of the treated skin. The patient's degree of satisfaction paralleled the physician's assessment of improvement. All patients reported improvement in hypopigmentation lasting greater than 3 months after the last treatment. Side effects were limited to mild pain during the treatment and mild posttreatment erythema and edema, which resolved in 2 to 4 days.Fractional resurfacing is a potentially effective modality for the treatment of hypopigmented scarring on the face. No adverse effects were observed.

    View details for DOI 10.1111/j.1524-4725.2007.33058.x

    View details for Web of Science ID 000244518000008

    View details for PubMedID 17338685

  • In vivo histological evaluation of a novel ablative fractional resurfacing device LASERS IN SURGERY AND MEDICINE Hantash, B. M., Bedi, V. P., Kapadia, B., Rahman, Z., Jiang, K., Tanner, H., Chan, K. F., Zachary, C. B. 2007; 39 (2): 96-107


    A novel carbon dioxide (CO(2)) laser device employing ablative fractional resurfacing was tested on human skin in vivo for the first time.An investigational 30 W, 10.6 microm CO(2) laser system was focused to a 1/e(2) spot size of 120 microm to generate an array of microscopic treatment zones (MTZ) in human forearm skin. A range of pulse energies between 5 and 40 mJ was tested and lesion dimensions were assessed histologically using hematoxylin and eosin. Wound healing of the MTZ's was assessed immediately-, 2-day, 7-day, 1-month, and 3-month post treatment. The role of heat shock proteins was examined by immunohistochemistry.The investigational CO(2) laser system created a microscopic pattern of ablative and thermal injury in human skin. The epidermis and part of the dermis demonstrated columns of thermal coagulation that surrounded tapering ablative zones lined by a thin eschar layer. Changing the pulse energy from 5 to 30 mJ resulted in a greater than threefold increase in lesion depth and twofold increase in width. Expression of heat shock protein (hsp)72 was detected as early as 2 days post-treatment and diminished significantly by 3 months. In contrast, increased expression of hsp47 was first detected at 7 days and persisted at 3 months post-treatment.The thermal effects of a novel investigational ablative CO(2) laser system utilizing fractional resurfacing were characterized in human forearm skin. We confirmed our previous ex vivo findings and show for the first time in-vivo, that a controlled array of microscopic treatment zones of ablation and coagulation could be deposited in human skin by varying treatment pulse energy. Immunohistochemical studies of heat shock proteins revealed a persistent collagen remodeling response lasting at least 3 months. We successfully demonstrated the first in-vivo use of ablative fractional resurfacing (AFR) treatment on human skin.

    View details for DOI 10.1002/lsm.20468

    View details for Web of Science ID 000244609500003

    View details for PubMedID 17311274

  • The effects of pulse energy variations on the dimensions of microscopic thermal treatment zones in nonablative fractional resurfacing LASERS IN SURGERY AND MEDICINE Bedi, V. P., Chan, K. F., Sink, R. K., Hantash, B. M., Herron, G. S., Rahman, Z., Struck, S. K., Zachary, C. B. 2007; 39 (2): 145-155


    We examined the effects of pulse energy variations on the dimensions of microscopic thermal injury zones (MTZs) created on human skin ex vivo and in vivo using nonablative fractional resurfacing.A Fraxel SR laser system emitting at 1,550 nm provided an array of microscopic spots at variable densities. Pulse energies ranging from 4.5 to 40 mJ were tested on human abdominal skin ex vivo and in vivo. Tissue sections were stained with hematoxylin and eosin (H&E) or nitro blue tetrazolium chloride (NBTC) and MTZ dimensions were determined. Ex vivo and in vivo results were compared. Dosimetry analyses were made for the surface treatment coverage calculation as a function of pulse energy and collagen coagulation based on H&E stain or cell necrotic zone based on NBTC stain.Each MTZ was identified by histological detection of a distinct region of loss of tissue birefringence and hyalinization, representing collagen denaturation and cell necrosis within the irradiated field immediately, 1, 3, and 7 days after treatment. At high pulse energies, the MTZ depth could exceed 1 mm and width approached 200 microm as assessed by H&E. NBTC staining revealed viable interlesional tissue. In general, no statistically significant difference was found between in vivo and ex vivo depth and width measurements.The Fraxel SR laser system delivers pulses across a wide range of density and energy levels. We determined that increases in pulse energy led to increases in MTZ depth and width without compromising the structure or viability of interlesional tissue.

    View details for DOI 10.1002/lsm.20406

    View details for Web of Science ID 000244609500009

    View details for PubMedID 17096412

  • Fractional Laser treatment for pigmentation and texture improvement. Skin therapy letter Rahman, Z., Alam, M., Dover, J. S. 2006; 11 (9): 7-11


    Fractional laser treatment with the 1,550 nm erbium fiber laser (Fraxel Laser, Reliant Technologies) has bridged the gap between the ablative and nonablative laser modalities used to treat the epidermal and dermal signs of skin aging. By targeting water as its chromophore, the laser induces a dense array of microscopic, columnar thermal zones of tissue injury that do not perforate or impair the function of the epidermis. The significant skin remodeling that ensues can be used to treat, with limited downtime, epidermal pigmentation, melasma, and rhytides, as well as textural abnormalities that include acne-related and surgical scars.

    View details for PubMedID 17075654