FRACTIONAL PHOTOTHERMOLYsis

Transcription

1 ORIGINAL ARTICLE 1550-nm Nonablative Laser Resurfacing for Facial Surgical Scars Annette M. Pham, MD; Ryan M. Greene, MD, PhD; Heather Woolery-Lloyd, MD; Joely Kaufman, MD; Lisa D. Grunebaum, MD Objective: To investigate the efficacy of 1550-nm (Fraxel SR1500 RE:Store; Solta Medical, Hayward, California) nonablative laser treatment of facial surgical scars. Methods: In this prospective clinical study, a volunteer sample of 13 adults with Fitzpatrick skin types I to III and facial surgical scars with a postoperative duration longer than 6 months were enrolled. Subjects were treated once every 4 weeks for a total of 4 treatments. Initial settings for the 1550-nm nonablative laser were at energy level 40 mj and treatment level 4 and were subsequently increased on each visit according to the patients tolerance level. Using a previously validated Patient and Observer Scar Assessment Scale (POSAS), the study subject and an independent evaluator completed assessments of the scar at each visit. Results: According to the Friedman test on ratings across all occasions after the first treatment to the last evaluation, there was a statistically significant improvement in the patient s assessment of the color, stiffness, thickness, and irregularity of the scar but not for pain or itching. For the observer s ratings, there was a statistically significant improvement in pigmentation, thickness, relief, and pliability but not for vascularization. Conclusions: Preliminary data suggest improved aesthetic results, demonstrating the potential use of fractional photothermolysis as a scar revision technique. Future studies with a longer follow-up period could elucidate the role of fractional photothermolysis in more permanent scar improvements. Arch Facial Plast Surg. 2011;13(3): Author Affiliations: University of Miami Cosmetic Medicine and Research Institute, Miami, Florida (Drs Woolery-Lloyd, Kaufman, and Grunebaum). Dr Pham is in private practice in Rockville, Maryland. Dr Greene is in private practice in Fort Lauderdale, Florida. FRACTIONAL PHOTOTHERMOLYsis is a nonablative resurfacing laser technique, in which the laser creates microthermal zones of injury randomly integrated onto the skin. Within these areas, localized epidermal necrosis occurs alongside collagen denaturation, followed by expulsion of the necrotic debris and neocollagenesis. 1 In the nonablated areas, these islands of normal skin serve as an epithelial bridge with factors that facilitate a quicker healing process. 1 Fractional photothermolysis using the 1550-nm nonablative wavelength has been approved by the Food and Drug Administration for the treatment of scars, including those resulting from acne and from surgery. There are several studies confirming the efficacy of fractional photothermolysis for treatment of acne scarring. However, clinical studies confirming the efficacy of treatment in surgical scars are lacking, and only 1 case report investigated its use for the treatment of a surgical scar. 2 Thus, in the present study, our objective was to investigate the efficacy of the 1550-nm nonablative laser (Fraxel SR1500 RE:Store; Solta Medical, Hayward, California) in the treatment of facial surgical scars. METHODS INCLUSION AND EXCLUSION CRITERIA In this prospective, single-center, clinical study (approved and conducted on full review by the University of Miami institutional review board), patients were selected from a volunteer sample of healthy adults (male and nonpregnant female patients), who had Fitzpatrick skin types I to III and facial surgical scars present for at least 6 months after surgery but less than 5 years. All scars had not been previously treated within the past 6 months. Study subjects did not have any relative medical contraindications to laser treatment, such as recent use of isotretinoin or anticoagulants; predisposition to keloids or excessive scarring; and a medical history of a cardiac pacemaker, an uncontrolled systemic disease, and/or any coagulation disorders. There were no racial or ethnic restrictions for the subjects, except where skin type was dictated by racial and ethnic origin (Table 1). 3 TREATMENT PROTOCOL All study subjects were screened at the initial visit for study participation according to the inclusion-exclusion criteria. If the study subject was selected at the initial visit, a test spot 203

2 treatment in the preauricular skin region was carried out. The starting point for the test spot treatment was at energy level 40 mj and at treatment level 4. Topical anesthetic (lidocaine hydrochloride, 7%, and tetracaine hydrochloride, 7%) was applied to the treatment area for 45 minutes prior to treatment. Proper laser safety precautions were instituted. All subjects were discharged with a nonchemical sunscreen as well as instructions for antiviral medication for those who had a history of facial and/or labial herpes. If there were no adverse events or complications following the test spot treatment, study subjects then received treatment at their facial surgical scar sites at the next visit. Treatment visits occurred once every 4 weeks (±14 days) for a total of 4 treatments. In addition, the study subjects returned for follow-up visits at 3 and 6 months after the last treatment for a total of 7 visits. On each subsequent treatment visit, the energy and treatment levels were increased at the study physician s discretion based on the subject s tolerance of treatment and adverse effects of pain and prolonged erythema. MAIN OUTCOME MEASURES Table 1. Classification and Features of Skin Types as Described by Fitzpatrick 3 Type Skin Color Features I White, freckles Always burns, never tans II White Usually burns III White to olive Sometimes burns, average tan IV Light brown Rarely burns, easily tans V Dark brown Very rarely burns, profuse tan VI Black Never burns, deeply pigmented Standardized photodocumentation of the facial surgical scars was obtained at each visit. The study subjects assessed their scar at each visit before the laser treatments were administered as well as on follow-up evaluations at 3 and 6 months after the last treatment. Subject assessments were made using the patient component of the Patient and Observer Scar Assessment Scale (POSAS). 4,5 The patient component of the POSAS contains 6 parameters in which the patient scores the characteristics of the scar according to pain, itching, color, stiffness, thickness, and irregularity. Each item was scored from 1 to 10, with 1 indicating that the scar had similar characteristics to the normal surrounding skin and 10 indicating that it was very different or the worst imaginable compared with the normal surrounding skin. 4 The independent evaluator (H.W.L.) performed live assessments of the scar, while a photograph of the scar from the previous visit was made available for reference purposes to reduce memory bias. The independent evaluator used the observer component of the POSAS, 4,5 which represented a modification of the previously validated Vancouver Scar Scale oftentimes used for studies involving qualitative scar assessments. 6 The independent evaluator scored the scar according to vascularization, pigmentation, pliability, thickness, and relief. Again, the scale was rated from 1 to 10, with 1 representing similarity to normal skin and 10 representing the worst scar imaginable. 4 STATISTICAL ANALYSIS Descriptive statistical methods were used to describe the demographic composition of the study subject population (age, sex, race/ethnicity, and Fitzpatrick skin type). In addition, data collection included the initial test spot and subsequent energy and treatment level settings for each subject s treatment visits as well as documentation of device malfunction or treatment interruption, assessment of pain, and/or discomfort immediately after treatment on a scale of 0 to 10 (0 indicates no pain and 10, severe pain ). Statistical analysis was performed using the Friedman test to determine if the study subjects and independent evaluator s ratings showed a statistically significant change from the baseline ratings across all occasions after the first treatment through to the last evaluation. RESULTS Of the 20 volunteers screened, there were 13 patients who met the inclusion criteria. There were 10 women and 3 men. The ages ranged from 36 to 72 years, and the mean age was 57 years. The number of patients in each of the skin type classifications included 4 patients with skin type I, 7 with skin type II, and 2 with skin type III. Table 2 lists the demographic composition of the study subject population as well as the initial test spot and subsequent energy and treatment level settings for each subject s treatment visits. Nearly all patients (n=12) had facial surgical scars resulting from reconstructive surgery after a Mohs resection of a skin cancer. Only 1 patient had a facial surgical Table 2. The Demographic Composition of the Study Subject Population as Well as the Energy Level/Treatment (Tx) Level for the Initial Test Spot and Subsequent Treatment Sessions and Whether the Patient Completed the Study to the 6-Month Follow-up Evaluation Patient No./ Sex/Age, y Race Skin Type Test Spot Tx1 Tx2 Tx3 Tx4 6-mo Follow-up? 1/F/66 White I 40/4 45/7 45/7 45/8 45/9 No 2/F/61 White I 40/4 40/6 45/8 45/9 45/9 Yes 3/M/62 White II 40/4 45/7 45/8 45/8 45/9 Yes 4/M/59 Hispanic III 40/4 40/6 45/7 45/7 45/8 Yes 5/F/61 White I 40/4 45/6 45/7 45/8 45/9 Yes 6/F/67 White III 40/4 40/6 45/7 45/8 45/8 No 7/F/53 White II 40/4 45/7 45/7 45/8 45/9 Yes 8/M/55 Hispanic I 40/4 45/7 45/7 45/8 45/8 Yes 9/F/72 White II 40/4 40/6 45/7 45/8 45/9 Yes 10/F/48 White II 40/4 45/6 45/7 45/7 45/8 Yes 11/F/54 White II 40/4 45/6 45/7 45/8 45/9 Yes 12/F/36 White II 40/4 40/6 45/7 45/8 45/9 No 13/F/53 White II 40/4 40/6 45/6 45/7 45/8 No 204

3 Table 3. Study Subject Assessment Scores Prior to Each Treatment Session and at the 3- and 6-Month Follow-up Evaluations Parameter Before Treatment 1 Before Treatment 2 Before Treatment 3 Before Treatment 4 3-mo FU 6-mo FU Patient 1 Pain NA Itching NA Color NA Stiffness NA Thickness NA Irregularity NA Patient 2 Color Stiffness Thickness Irregularity Patient 3 Itching Color Stiffness Thickness Irregularity Patient 4 Itching Color Stiffness Thickness Irregularity Patient 5 Color Stiffness Thickness Irregularity Patient 6 Pain NA Itching NA Color NA Stiffness NA Thickness NA Irregularity NA Patient 7 Color Stiffness Thickness Irregularity Patient 8 Pain Itching Color Stiffness Thickness Irregularity (continued) scar resulting from an elective cosmetic surgery (lower eyelid blepharoplasty). Per inclusion criteria, all scars had a postoperative duration of at least 6 months; however, 11 patients had scars less than 2 years old and 2 patients had scars older than 2 years. Nine of the patients completed the full study course including all 7 visits per study design protocol. On the 0 to 10 treatment scale, the mean pain score was approximately 2 for all sessions. No adverse events or complications were reported. All 13 patients underwent the 4 laser treatment sessions; however, patient 12 missed the 12-week and 24-week follow-up evaluations, while patients 1, 6, and 13 missed the 24-week follow-up evaluation (Table 2). Assessments of the scar by the patient (Table 3) as well as by the independent evaluator (Table 4) were recorded and tabulated separately for each of the parameters measured by the POSAS. There were 4 patients who were missing follow-up assessments, so their data points were excluded on initial statistical analysis. Then, statistical analysis was performed on all data points including those of the 4 aforementioned 205

4 Table 3. Study Subject Assessment Scores Prior to Each Treatment Session and at the 3- and 6-Month Follow-up Evaluations (continued) Parameter Before Treatment 1 Before Treatment 2 Before Treatment 3 Before Treatment 4 3-mo FU 6-mo FU Patient 9 Color Stiffness Thickness Irregularity Patient 10 Itching Color Stiffness Thickness Irregularity Patient 11 Pain Color Stiffness Thickness Irregularity Patient 12 Pain NA NA Itching NA NA Color NA NA Stiffness NA NA Thickness NA NA Irregularity NA NA Patient 13 Pain NA Itching NA Color NA Stiffness NA Thickness NA Irregularity NA Abbreviations: FU, follow-up; NA, a missed evaluation session. Table 4. Independent Evaluator Assessment Scores Prior to Each Treatment Session and at the 3- and 6-Month Follow-up Evaluations Parameter Before Treatment 1 Before Treatment 2 Before Treatment 3 Before Treatment 4 3-mo FU 6-mo FU Patient 1 Vascularization NA Pigmentation NA Thickness NA Relief NA Pliability NA Patient 2 Vascularization Pigmentation Thickness Relief Pliability Patient 3 Vascularization Pigmentation Thickness Relief Pliability Patient 4 Vascularization Pigmentation Thickness Relief Pliability (continued) patients by working on the null hypothesis assumption that if the patients had completed their follow-up evaluations, there should be no difference between the numerical ratings. No difference was found between the P values of both data collection sets (Table 5). 206

5 Table 4. Independent Evaluator Assessment Scores Prior to Each Treatment Session and at the 3- and 6-Month Follow-up Evaluations (continued) Parameter Before Treatment 1 Before Treatment 2 Before Treatment 3 Before Treatment 4 3-mo FU 6-mo FU Patient 5 Vascularization Pigmentation Thickness Relief Pliability Patient 6 Vascularization NA Pigmentation NA Thickness NA Relief NA Pliability NA Patient 7 Vascularization Pigmentation Thickness Relief Pliability Patient 8 Vascularization Pigmentation Thickness Relief Pliability Patient 9 Vascularization Pigmentation Thickness Relief Pliability Patient 10 Vascularization Pigmentation Thickness Relief Pliability Patient 11 Vascularization Pigmentation Thickness Relief Pliability Patient 12 Vascularization NA NA Pigmentation NA NA Thickness NA NA Relief NA NA Pliability NA NA Patient 13 Vascularization NA Pigmentation NA Thickness NA Relief NA Pliability NA Abbreviations: FU, follow-up; NA, a missed evaluation session. Overall, usingthefriedmantestonbaselineratingsacross all occasions, we found a statistically significant improvement in the patient s assessment of the color, stiffness, thickness, and irregularity of the scar but not for pain or itching (Table 5). For the observer s ratings, there was a statistically significant improvement in pigmentation, thickness, relief, and pliability but not for vascularization (Table 5). COMMENT Despite careful and atraumatic surgical technique, facial surgical treatment and/or reconstruction can result in facial scarring. The abnormal cascade of events that leads to cutaneous scarring has been well described. Briefly, the stages of wound healing include inflammation, proliferation, and remodeling. An aberration in these events, specifically excess cellular proliferation within wounds, can result in disorganized collagen deposition as well as abnormal pigmentation, leading to an obvious scar. 7 Acceptable and efficacious treatment of facial surgical scars is myriad including surgical revision, laser treatment, chemical peeling, dermabrasion, and topical treatment with bleaching creams and/or retinoids. Interestingly, comparisons among dermabrasion, chemi- 207

6 Table 5. Friedman Statistical Analysis Was Performed on 2 Data Collection Sets, One With and One Without the 4 Patients With Missed Follow-up Evaluations a A P Value Outcome Measure Data Collection Set With the 4 Patients Who Missed Follow-up Evaluations (n=13) Data Collection Set Without the 4 Patients Who Missed Follow-up Evaluations (n=9) Patient assessment Pain Itching Color Stiffness Thickness Irregularity Observer assessment Vascularization Pigmentation Thickness Relief Pliability B a There was no significant difference between the P values calculated. cal peels, and laser resurfacing revealed that laser resurfacing was more easily controlled as a treatment method. 8 Scar treatment with ablative lasers has become increasingly popular. However, ablative technology such as carbon dioxide and erbium (Er):YAG lasers are associated with long recovery or downtime. Fractional photothermolysis is a newer, nonablative resurfacing laser technique that has been approved by the Food and Drug Administration for treatment of surgical scars. This 1550-nm laser creates microzones or microthermal zones of injury that are randomly integrated onto the skin. Within these areas, localized epidermal necrosis occurs alongside collagen denaturation. Ultimately, the necrotic debris is expulsed and neocollagenesis occurs. In addition, because this laser treatment is nonablative, the islands of normal skin serve to speed the healing process. 1 Although the ideal number of treatments for scars is unknown, to maximize treatment results while taking into consideration wound turnover and healing, multiple treatments are often completed, ranging from 3 to 5 treatments on a monthly basis in most studies Therefore, in this study, the average of the industry standard at 4 treatments was chosen for the study protocol. There are several studies confirming the efficacy of fractional photothermolysis for the treatment of facial scarring. Glaich et al 11 reported on 7 patients who were treated with fractional photothermolysis for hypopigmented scars (secondary to inflammatory acne or gas fire burn). Patients received between 2 and 4 treatments at 4-week intervals. No adverse events were noted. Independent physician clinical assessment revealed improvements of 51% to 75% in hypopigmentation in 6 of 7 patients 4 weeks after final treatment. 11 Alster et al 12 described 53 patients who were treated with fractional laser photothermolysis for atrophic scars. No complications or adverse events were noted. Of the Figure 1. A 61-year-old woman with Fitzpatrick skin type I, who had a nasal scar after a Mohs reconstruction using a full-thickness skin graft. A, Before treatment. B, After 4 treatment sessions and on 6-month follow-up evaluation, there was significant improvement in color match of the scar compared with the surrounding skin, as rated by the study subject and the independent evaluator. patients, 91% had at least 25% to 50% improvement after a single treatment and 87%, who received 3 treatments, had at least 51% to 75% improvement in the appearance of scars after 1 month, with stable improvement after 6 months. 12 Hasegawa et al 13 reviewed 10 patients with acne scars using fractional photothermolysis. No patients had scarring or hyperpigmentation as a result of treatment. As judged by the patients themselves and physicians, all patients achieved clinical improvement. However, in all the aforementioned studies, investigations involved the use of fractional photothermolysis for the treatment of facial scarring other than those caused by surgery. In fact, at the time of this study s inception, there was only 1 case report in the literature that described the use of fractional photothermolysis for the treatment of surgical scars. 2 Behroozan et al 2 claimed a greater than 75% clinical improvement in a 55-year-old white woman with a surgical scar on the chin at 2 weeks after a single treatment based on an independent physician assessment. No significant adverse events were noted. 2 Finally, further review of the literature revealed an additional 2 abstracts (though unpublished manuscripts) involving 10 patients each who had improvement in early surgical scar treatment with the use of the 1550-nm nonablative laser. 14,15 In this study, there were 13 patients who were treated with a nonablative laser resurfacing procedure to achieve 208

7 A A B B Figure 2. A 62-year-old man with Fitzpatrick skin type II, who had a nasal scar after a Mohs reconstruction using local flaps. A, Before treatment. B, After 4 treatment sessions and on 6-month follow-up evaluation, there was a significant improvement in the vascularization of the scar as well as the color match to the surrounding normal skin. possible improvement of their facial surgical scars. The ratings for both the study subjects and the independent evaluator s assessments indicated that nonablative laser resurfacing is effective for surgical scar revision with little risk. Most of the patients perceived an improvement in color, especially since many of the scars were hypopigmented and there was improvement in the skin color match after the 4 laser treatments (Figure 1 and Figure 2). In addition, before treatment, many of the scars were considered stiff, thick, and irregular and after the laser treatments, most of the patients observed an improvement. Thus, statistical analysis on the ratings given by the study subjects showed a statistically significant improvement in the scar s color, stiffness, thickness, and irregularity. However, there were no changes in pain and itching ratings because the scars were considered stable 7 (ie, 6 months after surgery), which should not cause pain or itching. However, when looking at the patients ratings individually, there were 2 patients who did not notice overall improvement for all parameters (pain, itching, color, stiffness, thickness, and irregularity). Instead, 1 patient noted that while there was some improvement in the scar s stiffness, thickness, and irregularity, there was no change in its color because it remained hypopigmented compared with the patient s very ruddy, type II skin complexion (Figure 3). The second patient noted no change in stiffness or thickness of the scar but instead recorded Figure 3. A 54-year-old woman with Fitzpatrick skin type II, classified according to her tendency to sunburn, though she had a very ruddy complexion at baseline. She had a nasal scar after a Mohs reconstruction using a full thickness skin graft. A, Before treatment. B, On 6-month follow-up evaluation, even after completing 4 laser treatments, the scar still appeared hypopigmented compared with the surrounding skin (though her overall skin tone improved after sun avoidance). that the color and irregularity of the scar worsened over the 4 treatment sessions. Unfortunately, this patient was lost to follow-up on the 6-month evaluation, so it is unknown whether the ratings would have been different at that visit. Interestingly, the 2 patients who had ratings of either no change or worsening both had scars for more than 2 years after surgery as opposed to the other 11 patients who had scars less than 2 years after surgery. This suggests that laser treatment may be more effective for earlier treatment of scars, similar to dermabrasion techniques; however, further studies are needed to evaluate the observation. An analysis of the independent evaluator s ratings across all occasions for each patient revealed a statistically significant improvement in pigmentation, pliability, thickness, and relief, which is consistent with the study subjects assessments of color, stiffness, thickness, and irregularity. However, as expected, there was no change 209

8 in ratings for vascularization (vascularization of the scar referred to redness or increased blood vessels and telangiectasias within the scar) of the scar likely because almost all the surgical scars in the study were atrophic and hypopigmented. Overall, though statistically significant improvements in the scar characteristics were found based on both the patients and the observer s assessments, the study has obvious limitations as well. Because patients were volunteers for a research study, a selection bias is possible. In addition, neither the independent evaluator nor the patient was blinded to administration of treatment. Furthermore, though the POSAS has been previously validated as a reliable scar assessment tool, the ratings are still qualitative. Future studies could incorporate newer technologies of laser and 3-dimensional scanning to objectively measure scar characteristics of pigmentation, thickness, relief, pliability, and vascularization, and quantitative scales would then be needed. In conclusion, preliminary data suggest improved aesthetic results, demonstrating the potential use of nonablative fractional photothermolysis as a scar revision technique. Ultimately, though this study is a first step in determining the efficacy of the 1550-nm nonablative laser as a standard treatment for facial surgical scars, future studies will then take into account the present study s limitations. Future studies with a longer follow-up period could elucidate the role of fractional photothermolysis in more permanent scar improvements. Accepted for Publication: March 8, Correspondence: Annette M. Pham, MD, Metropolitan ENT & Facial Plastic Surgery LLC, Shady Grove Rd, Ste 100, Rockville, MD (drannette09@gmail.com). Author Contributions: Study concept and design: Pham, Woolery-Lloyd, Kaufman, and Grunebaum. Acquisition of data: Pham, Greene, Kaufman, and Grunebaum. Analysis and interpretation of data: Pham, Kaufman, and Grunebaum. Drafting of the manuscript: Pham and Grunebaum. Critical revision of the manuscript for important intellectual content: Greene, Woolery-Lloyd, Kaufman, and Grunebaum. Statistical analysis: Pham. Administrative, technical, and material support: Pham, Greene, Woolery-Lloyd, Kaufman, and Grunebaum. Study supervision: Woolery-Lloyd, Kaufman, and Grunebaum. Financial Disclosure: None reported. Previous Presentation: This study was presented at the Annual Meeting of the American Academy of Facial Plastic & Reconstructive Surgery; October 1, 2009; San Diego, California. REFERENCES 1. Manstein D, Herron GS, Sink RK, Tanner H, Anderson RR. Fractional photothermolysis: a new concept for cutaneous remodeling using microscopic patterns of thermal injury. Lasers Surg Med. 2004;34(5): Behroozan DS, Goldberg LH, Dai T, Geronemus RG, Friedman PM. Fractional photothermolysis for the treatment of surgical scars: a case report. J Cosmet Laser Ther. 2006;8(1): Fitzpatrick TB. The validity and practicality of sun-reactive skin types I through VI. Arch Dermatol. 1988;124(6): Draaijers LJ, Tempelman FRH, Botman YAM, et al. The patient and observer scar assessment scale: a reliable and feasible tool for scar evaluation. Plast Reconstr Surg. 2004;113(7): Truong PT, Lee JC, Soer B, Gaul CA, Olivotto IA. Reliability and validity testing of the Patient and Observer Scar Assessment Scale in evaluating linear scars after breast cancer surgery. Plast Reconstr Surg. 2007;119(2): Sullivan T, Smith J, Kermode J, McIver E, Courtemanche DJ. Rating the burn scar. J Burn Care Rehabil. 1990;11(3): Singer AJ, Clark RA. Cutaneous wound healing. N Engl J Med. 1999;341(10): Fitzpatrick RE, Tope WD, Goldman MP, Satur NM. Pulsed carbon dioxide laser, trichloroacetic acid, Baker-Gordon phenol, and dermabrasion: a comparative clinical and histologic study of cutaneous resurfacing in a porcine model. Arch Dermatol. 1996;132(4): Collawn SS. Fraxel skin resurfacing. Ann Plast Surg. 2007;58(3): Wanner M, Tanzi EL, Alster TS. Fractional photothermolysis: treatment of facial and nonfacial cutaneous photodamage with a 1,550-nm erbium-doped fiber laser. Dermatol Surg. 2007;33(1): Glaich AS, Rahman Z, Goldberg LH, Friedman PM. Fractional resurfacing for the treatment of hypopigmented scars: a pilot study. Dermatol Surg. 2007;33(3): Alster TS, Tanzi EL, Lazarus M. The use of fractional laser photothermolysis for the treatment of atrophic scars. Dermatol Surg. 2007;33(3): Hasegawa T, Matsukura T, Mizuno Y, Suga Y, Ogawa H, Ikeda S. Clinical trial of a laser device called fractional photothermolysis system for acne scars. J Dermatol. 2006;33(9): Rokhsar CK, Tse Y, Fitzpatrick R. Fractional photothermolysis on the treatment of scars [abstract]. Lasers Surg Med. 2005;36(S17): Fisher GH, Kim KH, Bangesh S, Bernstein LJ, Skover G, Gernonemus RG. Treatment of surgical scars with fractional photothermolysis [abstract]. Lasers Surg Med. 2005;36(S17):