Long-term results after CO2 laser skin resurfacing: a comparison of scanned and pulsed systems

Low-fluence treatment with a novel fractionated 2,910-nm fiber laser improves photodamage

BACKGROUND

Facial rejuvenation by lasers that target water has been a mainstay of esthetic laser treatments for decades. Modern lasers more commonly treat a fraction of the skin surface using ablative, semi-ablative, or nonablative pulses.

METHODS

Twenty subjects with visible evidence of chronic photoaging on the face were enrolled in this study. All subjects received two full-face, single-pass treatments spaced 2 months apart with the superficial mode of a 2910 nm fiber laser with an estimated penetration depth of 10 μm, 25% coverage, delivered in a 15 mm × 15 mm square microbeam pattern. A blinded comparison of pretreatment and 3-month post-treatment images was performed. Evaluation of biopsy samples for laser-tissue effects was performed on three separate subjects and biopsies were harvested 1-day post-treatment, 1-week post-treatment, and 2-weeks post-treatment.

RESULTS

Blinded evaluation of digital images revealed an average improvement score of 25.1 ± 14.5 (mean ± SEM) or 25.1%, using an 11-point scale evaluating overall improvement in photoaging (p < 0.001). Post-treatment effects were limited to mild-to-moderate erythema and edema, and the pain was rated a 1.9 out of a maximum of 10. Histology demonstrated superficial changes in the stratum corneum and epidermis with dermal inflammation present at 1-day post-treatment and 1-week post-treatment, with a return to baseline at 2 weeks.

CONCLUSIONS

The 2910 nm fiber laser is safe and effective for improving mild photodamage, with minimal discomfort and downtime. Dermal inflammation results from very superficial epidermal injury and may contribute to clinical improvement.

Recognizing and Managing Complications in Laser Resurfacing, Chemical Peels, and Dermabrasion

Skin resurfacing techniques allow improvement of skin texture and color. This includes the effacement of wrinkles, signs of photoaging, and the softening of scars. Laser resurfacing, chemical peels, and dermabrasion are associated with overlapping risks of complications. The most common of these include infection, hypopigmentation, hyperpigmentation, and scarring. Patient evaluation helps provide treatment that gives the maximal benefit with a minimization of risks. This includes understanding the extent of each patient's issues (Glogau scale) and Fitzpatrick type. A thorough knowledge of potential risks will reduce their incidence and optimize early recognition and treatment of these complications when they do occur.

Dermatologic Laser Side Effects and Complications: Prevention and Management

The evolution of modern laser and light-based systems has mirrored the demand for clinically effective treatments and the need for safer technologies with reduced postoperative recovery, side effects, and complications. With each new generation of lasers, more selective tissue destruction can be achieved with reduced unwanted sequelae. Patient selection and preparation, operator technique, and expeditious recognition and management of post-treatment side effects are paramount in avoiding complications and patient dissatisfaction. An overview of important variables to consider for dermatologic laser treatments are presented in order to provide a framework to reduce the severity and duration of possible post-treatment side effects and complications.

Lasers and ancillary treatments for scar management: personal experience over two decades and contextual review of the literature. Part I: Burn scars

The formation of a wide range of excessive scars following various skin injuries is a natural consequence of healing. Scars resulting from surgery or trauma affect approximately 100 million people per annum in the developed world and can have profound physical, aesthetic, psychological and social consequences. Thus, scar treatment is a priority for the plastic surgeon. We aim to explore new approaches to the management of such scarring. The senior authors current use of laser technology, chemotherapeutic agents, pharmacotherapy and cryosurgery will be reviewed. This is placed in the context of the current literature and evidence base and is illustrated with case studies, starting with burns scars in part I, and focusing on keloid and hypertrophic scars in part II, acne scars in part III and finally pigmented scars in part IV. In Part I we focus on burns scar treatment with fractional ablative 10,600 nm wavelength carbon dioxide (CO2) laser therapy.

Fractional carbon dioxide laser resurfacing

Currently available ablative fractional CO2 lasers provide excellent results and diminish down time with fewer complications than previous generation CO2 lasers. Mechanisms of action, treatment parameters, as well as pre- and postoperative care will be discussed.

An alternative approach for involutional entropion: a preliminary study

Involutional entropion is an inward rotation of the eyelid margin because of increased horizontal lid laxity, an overriding preseptal orbicularis, atrophied lid retractors, and involutional enophthalmos. There are a myriad of surgical approaches to treat involutional entropion, but the medical co-morbidities that are common in this patient population often make a less-invasive method more appropriate. In this study, a novel and less-traumatic method was tested. Tissue shrinkage effect of the CO(2) laser was used to create cicatricial changes to treat involutional entropion in five patients. Resurfacing was accomplished with the Ultra Pulse CO(2) (carbon dioxide) laser (model UP 5005, Coherent Medical Group, Santa Clara, CA) by the help of computerized pattern generator (CPG) scanning device. The first pass was performed to the entire lower lid and periorbital area, sparing the subciliary region, using 200 mJ of energy. The second pass used the same energy level, but this time resurfacing was extended as close as the lash line. All four of the five patients available for follow-up clinical evaluation (interval between 5 and 21 months) had surgical success with no recurrence of entropion, or symptoms such as itching or irritation. One of the patients who never came back for routine was lost to follow-up. The ectropion was never seen in the long-term follow-up. This method is a suitable alternative for elderly patients with comorbid conditions that prevent them from having invasive surgical procedures.

TUNEL assay to characterize acute histopathological injury following treatment with the active and deep FX fractional short-pulse CO2 devices

BACKGROUND

This is a report of the histopathological evaluation of the acute damage profile in human skin following treatment with two novel short-pulsed fractional carbon dioxide resurfacing devices used independently and in combination in vivo.

METHODS

The panni of eight abdominoplasty patients were treated with either the Active FX, the Deep FX (Lumenis Ltd., Yokneum, Israel), or a combination of the two (Total FX) prior to the start of the excisional surgical procedure. Multiple combinations of energies, pulse widths, and densities were evaluated for each device. After surgical removal (two to five hours), each pannus was immediately biopsied and samples were processed for histopathological evaluation.

RESULTS

The Active FX system resulted in extensive epidermal injury with wide shallow ablation craters that, at higher fluences, extended through the basement membrane of the epidermis into the papillary dermis. The Deep FX fractional treatment caused deep microcolumns of ablation penetrating up to 3 to 4 mm from the epidermal surface into the deep reticular dermis with a variable rim of coagulated collagen surrounding each ablation column.

CONCLUSIONS

The in vivo histopathological evaluation of these devices furthers our understanding of the fundamental laser/tissue interaction following treatment with each device independently and in combination.

The use of hydroquinone with facial laser resurfacing

BACKGROUND

One complication of laser resurfacing that is especially common in people with skin types III-VI is hyperpigmentation. This may last for several months after the laser resurfacing procedure.

OBJECTIVE

To review the literature and detail the author's use of various techniques, including hydroquinone cream, in patients who develop pigmentation after laser resurfacing.

CONCLUSION

Limiting the amount of non-specific thermal and minimizing inflammation should help limit post-laser resurfacing hyperpigmentation. If pigmentation occurs, the use of hydroquinone cream with other depigmenting agents speeds its resolution.

Nd:YAG laser combined with IPL treatment improves clinical results in non‐ablative photorejuvenation

BACKGROUND

Intense pulsed light (IPL) sources have been reported in non-ablative photorejuvenation, but the excellent histological findings do not always coincide with the clinical results and patient satisfaction index (SI).

METHODS

Ten female patients (two forehead, four periocular and four perioral), ages ranging from 28 to 46 years, skin types II-IV, wrinkle types I-III, participated in the study. The IPL system was applied with the yellow (570 nm) cut-off filter, 30 J/cm(2), single pulse, followed by the Nd:YAG at 120 J/cm(2), double pulse (7 ms per shot with 20 ms between pulses) on the wrinkled areas only. Three sessions were given at monthly intervals, and an assessment was made 1 and 6 months after the third session. Biopsies were taken from four consenting patients as a cross-section before the first treatment and then 1 and 6 months after the third session. For clinical control and contrast of tissue results, a group of 10 patients (two forehead, four periocular and four perioral; ages ranging from 27 to 47 years, skin types II-IV, wrinkle types I-III) was treated only with IPL, using the same parameters and sessions. Histologies were taken from four consenting patients.

RESULTS

The histology showed thickening of the epidermis with good dermal collagen organization in both groups. However, the combined treatment showed more dramatic changes in histological tissue condition, and ectatic blood vessels were seen in the deeper dermis. The patient SI values, related to the results, were lower when IPL was used alone. All patients completed the study. In the combined treatment group, overall SIs of 8 (80%) and 8 (80%) were obtained at the control points of 1 and 6 months, respectively, after session 3, compared with SIs of 6 (60%) and 4 (40%) scored by patients in the IPL group at the same points. Discomfort and side effects were minimal in both groups.

CONCLUSIONS

The addition of the Nd:YAG laser to the IPL regimen in non-ablative skin rejuvenation gave very good histological results, which were echoed by stronger patient satisfaction than in the control group treated only with IPL. Visible improvement in the skin condition of both groups was achieved, but was better in the combined treatment group.

A preliminary clinical and histopathological study of laser skin resurfacing using a frequency-doubled Nd:YAG laser after application of Chromofilm ®

BACKGROUND AND OBJECTIVES

Carbon dioxide (CO2) and Er:YAG lasers are commonly used for laser skin resurfacing. In demonstrating their efficacy, intra- and interoperator variability may be important. In attempting to solve this problem, a new concept was developed which combines a previous application of an exogenous chromophore onto the skin in a standardized way (Chromofilm) and irradiation with a millisecond, low-power pulsed laser.

MATERIALS AND METHODS

This study aimed to evaluate this new concept in vivo in human skin using a 532-nm Nd:YAG laser connected to a scanner using the following parameters: 532 nm, 2W, 1-mm spot size, 30-mm2 hexagonal surface irradiation and 50-120-ms pulse duration. The laser irradiation was performed both 15 h and 1 h prior to the facelift procedure. Tissue samples were examined histologically to determine the injury depth using nitroblue-tetrazolium chloride (NBTC) staining, haematoxylin-eosin staining and Masson's staining.

RESULTS

Morphometric analysis of histological preparations showed that the depth of injury was dose-dependent: 50-ms pulse duration induced total epidermis ablation and fine dermal coagulation; 120-ms pulse duration induced dermal coagulation down to 120 microns. No residual carbon film was observed on histologic sections.

CONCLUSION

Laser skin resurfacing using a 532-nm laser irradiation after application of a carbon film transfer is an effective method for skin resurfacing. With this new galenic approach (Chromofilm), the control of all parameters (thickness, chromophore concentration and distribution) can be achieved to predict the thermal injury obtained after laser irradiation.

The safety of hydroquinone: A dermatologist's response to the 2006 Federal Register

Recently, the US Food and Drug Administration proposed a ban on over-the-counter hydroquinone mainly on the basis of high absorption, reports of exogenous ochronosis in humans, and murine hepatic adenomas, renal adenomas, and leukemia with large doses over extended time periods. Systemic exposure to hydroquinone from routine topical application is no greater than that from quantities present in common foods. While murine hepatic adenomas increased, murine hepatocellular carcinomas decreased, suggesting a protective effect. Renal tumors are sex, species, and age specific and therefore do not appear relevant to humans after decades of widespread use. Murine leukemia has not been reproducible and would not be expected from small topical doses. Finally, a literature review of exogenous ochronosis and clinical studies employing hydroquinone (involving over 10,000 exposures under careful clinical supervision) reveal an incidence of exogenous ochronosis in the United States of 22 cases in more than 50 years. Therefore, the proposed ban appears to be unnecessarily extreme.

In vivo histological evaluation of a novel ablative fractional resurfacing device

BACKGROUND AND OBJECTIVES

A novel carbon dioxide (CO(2)) laser device employing ablative fractional resurfacing was tested on human skin in vivo for the first time.

STUDY DESIGN/MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSION

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.

Laser-Faltenbehandlung

Prolonged exposure to UV-radiation induces a variety of visible skin changes such as lentigines, actinic keratoses and solar elastosis. Laser skin resurfacing using ablative lasers (CO(2) or Erbium:YAG) is a popular procedure to reduce these marks and improve the aesthetic appearance of photoaged facial skin. Skin resurfacing is defined as an ablation of the upper layers of facial skin. Possible side effects are hyperpigmentation, hypopigmentation and, at worst, scarring. The"down time" after the skin resurfacing procedure is about 7 to 10 days. This is the major drawback of resurfacing and the main reason why subsurfacing/skin rejuvenation is becoming even more popular. The literature is not clear on whether this newer approach is as effective as resurfacing.

Facial rejuvenation and light: our personal experience

The treatment of ageing skin remains a very hot topic, and many systems have been reported as having varying degrees of success. Nonablative lasers were developed to avoid the problematic and uncomfortable sequelae following laser ablative resurfacing, and while there was no downtime, there was also poor patient satisfaction. The same was true of the intense pulsed light systems. The use of different modalities in various combinations was found to offer much better results, however, such as a 595-nm pulsed dye laser followed by a 1,450-nm diode laser, and so on, all used at subablative thresholds. The recent entry of blue and infrared tunable plasma light and light-emitting diodes into the skin rejuvenation arena has attracted a great deal of attention. The authors suggest that no single modality can accomplish all the complex events required for effective skin rejuvenation, suggest that combination phototherapy is the best approach combined with an adjunctive epidermal care regimen, and demonstrate their development of this methodology.

Nonablative Laser Surgery for Pigmented Skin

BACKGROUND

Nonablative laser surgery has been proven to improve early photodamaged skin and acne scars. These techniques include treatments with lasers, light sources, and/or radiofrequency devices.

OBJECTIVES

To review the history of nonablative technology and its applicability to darker skin types and to provide an objective look at the various published studies documenting the efficacy of nonablative technology.

CONCLUSION

Nonablative laser surgery can improve skin quality and acne scars in all skin types. Complications are rare but can occur. Future studies are required to compare the efficacy of the various nonablative technologies.

Long-term treatment of photoaged human skin with topical retinoic acid improves epidermal cell atypia and thickens the collagen band in papillary dermis

BACKGROUND

Risk of photocarcinogenesis and the relevance of collagen in wrinkle effacement are two issues related to prolonged use of retinoic acid (RA) that have not been fully addressed.

OBJECTIVE

Our purpose was to investigate the degree of epidermal cellular atypia and the thickness of papillary dermal collagen in photoaging after long-term use of RA.

METHODS

Thirty-four subjects with photoaged skin were treated daily with 0.05% RA for at least 6 months. Epidermal cellular atypia was graded by means of a semiquantitative scale. Thickness of collagen band was measured by using image-analysis software.

RESULTS

Compared with pretreatment findings, melanocytic and keratinocytic atypia was significantly reduced and the collagen band thickness doubled.

LIMITATIONS

This was an open-label study.

CONCLUSION

Improvement in epidermal cellular atypia is consistent with the ability of RA to act as a chemopreventive agent in epithelial carcinogenesis. Prolonged use also significantly increased collagen matrix deposition in dermal repair zones, which most likely contributes to wrinkle effacement by RA.

Healing Process of Skin after CO2 Laser Ablation at Low Irradiance: A Comparison of Continuous-Wave and Pulsed Mode

OBJECTIVE

The purpose of the present study was to compare the healing process of rabbit's skin after the ablation of continuous wave CO(2) laser and pulsed CO(2) laser at low irradiances.

BACKGROUND DATA

Because of its advantages, the CO(2) laser has been viewed as an alternative to the traditional scalpel. Simple thermal models suggest that suitably short pulses of laser irradiation can leave a smaller thermal damaged zone to ablated tissue, which may lead to faster healing.

METHODS

One continuous-wave (cw, 2 watt) and two pulsed CO(2) lasers (sp(1), 100 Hz, 2 watt; and sp(2), 25 Hz, 2 watt) were used to ablate twelve rabbits' ear skin for 2 min, respectively. After sacrifice at 0, 3, 7, 14, 28, and 56 days postsurgery, gross observation and histological examination were performed.

RESULTS

sp(1) and sp(2) resulted in similar ablation rates to cw laser. At 3, 7, 14, and 28 days postsurgery, the scores of the group cw were significantly lower than both the sp(1) and sp(2) scores (p < 0.01). From 7 to 28 days, wounds of sp1 showed the best histological outcomes.

CONCLUSION

At a relatively low irradiance, pulsed CO(2) laser is capable of bloodless skin ablation with improved wound healing. Increasing repetition rate of the CO(2) laser may help to achieve a better surgical outcome. Pulsed CO(2) laser may be a valuable instrument for ablation skin and skin lesions.

Analysis of hyperpigmentation and hypopigmentation after Er:YAG laser skin resurfacing

BACKGROUND AND OBJECTIVES

Pigmentary disorders--such as hyperpigmentation and hypopigmentation, are devastating complications of erbium:yttrium-aluminum-garnet (Er:YAG) laser resurfacing. This study was undertaken to assess the clinical and histopathologic features of hyperpigmentation and hypopigmentation following Er:YAG laser resurfacing, especially in darker skin.

STUDY DESIGN/MATERIALS AND METHODS

One hundred and ninety patients (skin phototypes III and above), treated with Er:YAG lasers--short-pulsed and modulated (variable-pulsed and dual-mode) Er:YAG lasers--for skin resurfacing were recruited. The clinical features of hyperpigmentation and hypopigmentation were evaluated retrospectively using medical charts and serial photographs. For histopathologic examinations, skin biopsies were performed in three patients at hyperpigmentation sites and in four patients at hypopigmentation sites.

RESULTS

Hyperpigmentation was observed in 38.4% of the patients. Mean onset and duration were 3.5 and 7.2 weeks, and then it has faded away within 16 weeks in 93.2% of cases. Hypopigmentation was observed in 13.7% of the patients; its mean onset was 2 months after treatment, and it faded within 1 year in 85% of cases. The incidences and mean durations of these side effects were more intense and longer in patients treated with short-pulsed, variable-pulsed, and dual-mode Er:YAG lasers, in increasing order. In terms of histopathologic examinations, melanin amounts in the epidermal basal layer were observed to vary.

CONCLUSIONS

Hyperpigmentation and hypopigmentation are frequent complications of Er:YAG laser resurfacing. Long pulse duration-induced thermal damage seems to be the most important factor in terms of the induction of pigmentary disorders.

Tretinoin treatment before carbon-dioxide laser resurfacing: A clinical and biochemical analysis

BACKGROUND

Tretinoin is often prescribed before laser resurfacing in an attempt to enhance results.

OBJECTIVE

We sought to assess the clinical and biochemical effects of preoperative tretinoin use before laser resurfacing.

METHODS

Patients were randomized to apply tretinoin to one forearm and placebo to the other for 3 weeks. Patients' photodamaged forearms were focally treated by carbon-dioxide laser resurfacing. Biopsy specimens were obtained at baseline and various times posttreatment. Real-time polymerase chain reaction technology was used to quantify messenger RNA levels of types I and III procollagen and matrix metalloproteinases-1, 3, and 9. Wounds were assessed for degree of re-epithelialization using a computer graphics-generated template. A colorimeter was used to quantify postoperative erythema.

RESULTS

No substantial differences in either biochemical markers or clinical end points were identified between tretinoin and placebo pretreated forearms.

CONCLUSIONS

We found no evidence of enhanced collagen formation, accelerated re-epithelialization, or quicker resolution of postoperative erythema with tretinoin pretreatment before laser resurfacing.

Combined Nonablative Skin Rejuvenation with the 595- and 1450-nm Lasers

BACKGROUND

Histologic findings are not echoed in the visible effect in the epidermis after skin rejuvenation.

SUBJECTS AND METHODS

Ten women (Group A) received five treatment sessions with a 595-nm pulsed dye laser immediately followed by a 1450-nm diode laser. Two other demographically similar groups of 10 patients each, Groups B and C, were treated with the 595-nm pulsed dye laser or the 1450-nm diode laser alone, respectively.

RESULTS

Good dermal collagen remodeling was observed in Group A. Overall better and faster results were seen in Group A. The 6-month clinical outcome was best in Group A followed by Group C and Group B.

CONCLUSIONS

Wavelengths of 595 plus 1450 nm for skin rejuvenation produced good results with much higher patient satisfaction than those obtained with the 595- or 1450-nm wavelengths alone.

Improvement of neck and cheek laxity with a nonablative radiofrequency device: a lifting experience

OBJECTIVE

Laxity of cheek and neck skin is a common cosmetic complaint of patients as they age. Improvement of skin laxity can be difficult to achieve without invasive surgical lifting procedures. The object of this study was to evaluate the safety and efficacy of a novel nonablative radiofrequency device in the treatment of cheek and neck laxity.

METHODS

Fifty patients (skin phototypes I to IV) with mild-to-moderate cheek laxity (n=30) or neck laxity (n=20) received one treatment with a radiofrequency device (ThermaCool; Thermage Corp., Hayward, CA). Topical anesthetic cream was applied under occlusion for 60 minutes before treatment of the skin extending laterally and inferiorly from the nasolabial folds to the preauricular regions and mandibular ridge for treatment of the cheeks and from the mandible to mid neck for treatment of the neck. Clinical improvement of treatment areas was independently determined by three masked assessors' evaluations of comparative photographs at baseline, immediately after treatment, at 1 week, and at 1, 3, and 6 months after treatment using a quartile grading scale (0=less than 25%, 1=25% to 50%, 2=51% to 75%, 3=more than 75% improvement). Patient satisfaction surveys were also obtained at each follow-up visit.

RESULTS

Significant improvement in cheek and neck skin laxity was observed in the majority of patients. Patient satisfaction scores paralleled the clinical improvements observed. Side effects were mild and limited to transient erythema, edema, and rare dysesthesia. No scarring or pigmentary alteration was seen.

CONCLUSIONS

Noninvasive radiofrequency bulk dermal heating of skin can achieve safe and effective tissue tightening of the cheeks and neck. Although tightening continued to be evident 6 months after a single treatment, the longevity of clinical results has yet to be determined.

New computer-guided scanner for improving CO2 laser-assisted microincision

The objective was to clinically test a new computer-guided scanner designed for CO2 laser-assisted microincision. The scanner-assisted beam travels across the target as a straight or curved incision line. Line length and beam penetration can be adjusted. The studied population, 155 cases, encompassed benign lesions as well as early cancers of the larynx. Operating time was compared with that required for similar operations performed with the Acuspot micromanipulator. Laser-produced coagulation thickness at the incision was measured on 41 operative specimens. The scanner-assisted incision and dissection were more accurate and required up to 30% less time than with a manually guided beam. Postoperative follow-up was straightforward. The coagulation thickness was less than 10 microm for phonomicrosurgery and less than 20 microm for other surgical procedures. The scanner-assisted incision is more accurate than that attained manually.

Comparison of a 1450-nm Diode Laser and a 1320-nm Nd:YAG Laser in the Treatment of Atrophic Facial Scars: A Prospective Clinical and Histologic Study

BACKGROUND

Atrophic scar revision techniques, although numerous, have been hampered by inadequate clinical responses and prolonged postoperative recovery periods. Nonablative laser treatment has been shown to effect significant dermal collagen remodeling with minimal posttreatment sequelae. Although many studies have been published regarding the effectiveness of these nonablative lasers on rhytides, there are limited data demonstrating their specific effects on atrophic scars.

OBJECTIVE

To evaluate and compare the efficacy and safety of long-pulsed 1320-nm Nd:YAG and 1450-nm diode lasers in the treatment of atrophic facial scarring.

METHODS

A series of 20 patients (skin phototypes I-V) with mild to moderate atrophic facial acne scars randomly received three successive monthly treatments with a long-pulsed 1320-nm Nd:YAG laser on one facial half and a long-pulsed 1450-nm diode laser on the contralateral facial half. Patients were evaluated using digital photography and three-dimensional in vivo microtopography measurements at each treatment visit and at 1, 3, 6, and 12 months postoperatively. Histologic evaluations of cutaneous biopsies obtained before treatment, immediately after the first treatment, and at 1, 3, 6, and 12 months after the third treatment were performed. Clinical assessment scores were determined at each treatment session and follow-up visit. Patient satisfaction surveys were obtained at the end of the study.

RESULTS

Mild to moderate clinical improvement was observed after the series of three treatments in the majority of patients studied. Patient satisfaction scores and in vivo microtopography measurements paralleled the photographic and histopathologic changes seen. Side effects of treatment were limited to mild transient erythema, edema, and hyperpigmentation. No scarring or adverse textural changes resulted from the use of either laser system.

CONCLUSIONS

Nonablative long-pulsed 1320-nm Nd:YAG and 1450-nm diode lasers each offer clinical improvement for patients with atrophic scarring without significant side effects or complications. The 1450-nm diode laser showed greater clinical scar response at the parameters studied. The use of nonablative laser systems is a good treatment alternative for patients with atrophic scarring who are unable or unwilling to endure the prolonged postoperative recovery process associated with ablative laser skin resurfacing procedures.

Lack of difference in the rates of hypopigmentation with 90-microsecond pulsed and longer dwell time carbon-dioxide laser resurfacing

BACKGROUND

Hypopigmentation is an adverse outcome associated with carbon-dioxide (CO(2)) laser resurfacing. A 90-microsecond pulse produces a more favorable postoperative course of healing, erythema, and pain compared with a 900-microsecond dwell time. The rate of hypopigmentation after 90-microsecond pulsed CO(2) resurfacing may also be reduced. To date, there have been no comprehensive reports on the effect of varying pulse duration on the occurrence of hypopigmentation.

OBJECTIVE

We sought to investigate the relationship between pulse duration and the occurrence of hypopigmentation after CO(2) laser resurfacing.

METHODS

We conducted a retrospective review of 447 consecutive patients who were treated with a 90-microsecond pulsed CO(2) laser (n = 229) or a continuous wave CO(2) laser with a modifiable dwell time (100-950 microseconds, n = 218). Follow-up ranged from 8 to 61 months (median: 27).

RESULTS

A series of 4 threshold dwell times (range: 90-950 microseconds) were used to divide patients into 2 treatment groups (above and below) at each threshold. The rates of hypopigmentation between groups were similar (range: 6.37%-9.09%) and serial chi-square testing revealed no statistical differences between groups for each dwell time tested (P < 1.0).

CONCLUSION

No significant relationship between pulse duration and the occurrence of hypopigmentation was observed.

Full face laser resurfacing: Therapy and prophylaxis for actinic keratoses and non-melanoma skin cancer

BACKGROUND

Although there are many effective treatment modalities for individual actinic keratoses (AKs), widespread lesions on the photoaged face pose a challenge due to inefficient and ineffective therapy resulting in high rates of recurrence after local destruction. Full face laser resurfacing offers an effective and efficient treatment option that successfully reduces the number of AK's on diffusely damaged skin and may show a prophylactic benefit for preventing non-melanoma skin cancers.

OBJECTIVE

To assess the efficacy of full face laser resurfacing in reducing the number of facial AK's by comparing preoperative and postoperative numbers of lesions present and to observe the incidence of non-melanoma skin cancer after full face laser resurfacing.

STUDY DESIGN

A retrospective chart review of 24 patients with widespread facial AK's (greater than 30) treated with full face UPCO(2) and/or Er:Yag laser resurfacing was performed. All patients were a minimum of 1 year post-operative following facial laser resurfacing. The recurrence of AK's and the occurrence of facial non-melanoma skin cancers in these patients was assessed through chart analysis.

RESULTS

Widespread AK's were effectively eliminated in all patients. Twenty-one patients (87%) remained lesion free for at least 1 year. Fourteen of the 24 patients (58.3%) showed no new lesions during a 2-year follow-up. There was an overall 94% reduction in total number of AK's. Adverse effects included transient perioral scarring in one patient, S. aureus infection in two patients, and dyschromia in two patients.

CONCLUSIONS

Full face laser resurfacing provides long-term effective prophylaxis against AKs and may reduce the incidence of AK related squamous cell carcinoma.

Lasers for facial rejuvenation

Laser and laser-like assisted facial rejuvenation has become very popular during the last decade. Although a myriad of techniques are available, such approaches can be divided into four basic approaches. There are those that (i) ablate the epidermis, cause dermal wounding, and provide a significant thermal effect (CO(2) lasers); (ii) ablate the epidermis, cause dermal wounding, and minimal thermal effects (short pulsed Erbium:Ytrrium-Aluminum-Garnet [Er:YAG] lasers); (iii) ablate the epidermis, cause dermal wounding, and provide variable thermal effects (combined CO(2)/Er:YAG lasers, variable pulsed Er:YAG lasers, and ablative radiofrequency devices); and (iv) do not ablate the epidermis, cause dermal wounding, and provide minimal thermal effects (non-ablative lasers and light sources). Each of the four modalities has now been shown to be effective in promoting facial rejuvenation. As would be expected, each has some advantages and disadvantages.CO(2) lasers, because they ablate the epidermis, cause a dermal wound, and provide a significant thermal effect, appear to be most useful for those individuals with advanced photoaged skin. Such lasers provide the greatest degree of skin tightening for these individuals. However, it is that very same thermal effect that leads to the possibility of delays in healing sometimes noted with these systems. Short pulsed Er:YAG lasers, because they promote so little thermal damage, when used in a superficial manner, lead to the possibility of quicker healing than is seen with CO(2) lasers. However, less clinical improvement and more bleeding may be noted. Combined CO(2)/Er:YAG lasers, variable pulsed Er:YAG lasers, and ablative radiofrequency devices lead to an effect somewhere in between that of pulsed CO(2) lasers and short pulsed Er:YAG lasers. The newest group of systems includes the non-ablative devices that do not ablate the epidermis, cause dermal wounding, and provide for a minimal thermal effect. This area of technology is still evolving. Although such techniques, because they do not ablate the epidermis, are cosmetically elegant, the clinical results are usually not quite as good as the more aggressive ablative techniques.

Pulsed and scanned carbon dioxide laser resurfacing 2 years after treatment: comparison by means of scanning electron microscopy

Studies have reported short-term and long-term (1-year) findings for laser skin resurfacing. Two of the most popular systems used for this procedure, the continuous-wave Sharplan 40C SilkTouch system and the pulsed Coherent 5000C UltraPulse system with a computer pattern generator, were previously compared for a range of follow-up times up to 1 year, using light microscopy and transmission electron microscopy. This study analyzed the 2-year morphological differences using scanning electron microscopy. Tissue samples were obtained from 10 patients (age range, 50 to 72 years; skin types II and III) who had undergone laser resurfacing 2 years previously. One half of the face of each patient had been treated with the continuous-wave system and the other half with the pulsed system. The samples were subjected to scanning electron microscopy. On the continuous-wave-treated side, significantly better dermal collagen organization was observed at 2 years, with plump-appearing fibers that were closely knit to form a compact structure. On the side treated with the pulsed system, the collagen fibers in the papillary dermis were more loosely arranged and appeared drier. In both the continuous-wave-treated and pulsed-treated areas, the epidermis appeared healthy and exhibited some signs of age-related deterioration, with slightly flatter plaques and somewhat more flaking keratin on the pulsed-treated side. Probably because of the greater degree of residual thermal damage associated with the continuous-wave system, at 2 years after treatment there was more prolific synthesis and better orientation of collagen fibers, which were maintained for longer times, compared with the pulsed-treated specimens.

Facial resurfacing in patients with Fitzpatrick skin type IV

BACKGROUND AND OBJECTIVES

Though post-inflammatory hyperpigmentation (PIH) is probably the most common complication of laser resurfacing and appears to correlate directly with the intensity of the patient's natural pigmentation, there is very little data that specifically addresses the risks of dyspigmentation in more darkly pigmented patients (Fitzpatrick skin types IV and above). The objective of this study was to evaluate the long-term dyspigmentation of patients with skin type IV having radial laser resurfacing.

STUDY DESIGN/MATERIALS AND METHODS

A retrospective review of the clinical efficacy, incidence of dyspigmentation and other adverse effects, as well as the pre/post-operative protocol of 22 patients with Fitzpatrick skin type IV who were a minimum of 1 year post-operative following facial laser resurfacing.

RESULTS

The average patient achieved greater than 50% improvement, indicating adequate treatment being delivered. PIH occurred in 68% of patients, starting 1 month post-operative and lasting 3.8 months. There was no correlation to pre-treatment or type of laser used as far as incidence of PIH. True hypopigmentation was not seen in this group of 22 patients.

CONCLUSIONS

PIH is the most common complication of facial resurfacing in patients with skin type IV. It is not preventable by choice of laser or skin care regimen pre-operative, but appears to respond to appropriate treatment once it has developed.

Side effects and complications of laser therapy

Laser skin surgery is not without risk and some degree of downtime in most situations. Patient satisfaction is key to the perceived success of the procedure. Therefore, the physician must fully explain all risks, potential complications, and expected morbidity associated with any laser treatment to be performed. Although many side effects can be avoided by use of appropriate intraoperative technique and adequate postoperative management, untoward effects may still occur and must be promptly identified and addressed. An informed patient is an important factor in the healing process and contributes to the success of the procedure.

Er:YAG laser skin resurfacing

Recent advances in Er:YAG laser technology have dramatically enhanced the ability to resurface the skin safely. Selection of precise ablation and coagulation levels allows laser surgeons to modify these variables to fit the esthetic concerns of individual patients. These systems truly represent a viable alternative to conventional CO2 laser resurfacing.