The Experts below are selected from a list of 813 Experts worldwide ranked by ideXlab platform
Jeffrey S. Dover - One of the best experts on this subject based on the ideXlab platform.
-
Fractional Laser Skin Resurfacing.
Journal of drugs in dermatology : JDD, 2012Co-Authors: Macrene Alexiades-armenakas, Jeffrey S. Dover, Kenneth A. ArndtAbstract:Laser Skin Resurfacing (LSR) has evolved over the past 2 decades from traditional ablative to fractional nonablative and fractional ablative Resurfacing. Traditional ablative LSR was highly effective in reducing rhytides, photoaging, and acne scarring but was associated with significant side effects and complications. In contrast, nonablative LSR was very safe but failed to deliver consistent clinical improvement. Fractional LSR has achieved the middle ground; it combined the efficacy of traditional LSR with the safety of nonablative modalities. The first fractional Laser was a nonablative erbium-doped yttrium aluminum garnet (Er:YAG) Laser that produced microscopic columns of thermal injury in the epidermis and upper dermis. Heralding an entirely new concept of Laser energy delivery, it delivered the Laser beam in microarrays. It resulted in microscopic columns of treated tissue and intervening areas of untreated Skin, which yielded rapid reepithelialization. Fractional delivery was quickly applied to ablative wavelengths such as carbon dioxide, Er:YAG, and yttrium scandium gallium garnet (2,790 nm), providing more significant clinical outcomes. Adjustable Laser parameters, including power, pitch, dwell time, and spot density, allowed for precise determination of percent surface area, affected penetration depth, and clinical recovery time and efficacy. Fractional LSR has been a significant advance to the Laser field, striking the balance between safety and efficacy.
-
the spectrum of Laser Skin Resurfacing nonablative fractional and ablative Laser Resurfacing
Journal of The American Academy of Dermatology, 2008Co-Authors: Macrene Alexiadesarmenakas, Jeffrey S. Dover, Kenneth A. ArndtAbstract:The drive to attain cosmetic facial enhancement with minimal risk and rapid recovery has inspired the field of nonsurgical Skin rejuvenation. Laser Resurfacing was introduced in the 1980s with continuous wave carbon dioxide (CO 2 ) Lasers; however, because of a high rate of side effects, including scarring, short-pulse, high-peak power, and rapidly scanned, focused-beam CO 2 Lasers and normal-mode erbium-doped yttrium aluminium garnet Lasers were developed, which remove Skin in a precisely controlled manner. The prolonged 2-week recovery time and small but significant complication risk prompted the development of non-ablative and, more recently, fractional Resurfacing in order to minimize risk and shorten recovery times. Nonablative Resurfacing produces dermal thermal injury to improve rhytides and photodamage while preserving the epidermis. Fractional Resurfacing thermally ablates microscopic columns of epidermal and dermal tissue in regularly spaced arrays over a fraction of the Skin surface. This intermediate approach increases efficacy as compared to nonablative Resurfacing, but with faster recovery as compared to ablative Resurfacing. Neither nonablative nor fractional Resurfacing produces results comparable to ablative Laser Skin Resurfacing, but both have become much more popular than the latter because the risks of treatment are limited in the face of acceptable improvement. Learning objectives At the completion of this learning activity, participants should be familiar with the spectrum of Lasers and light technologies available for Skin Resurfacing, published studies of safety and efficacy, indications, methodologies, side effects, complications, and management.
-
The spectrum of Laser Skin Resurfacing: Nonablative, fractional, and ablative Laser Resurfacing
Journal of the American Academy of Dermatology, 2008Co-Authors: Macrene Alexiades-armenakas, Jeffrey S. Dover, Kenneth A. ArndtAbstract:The drive to attain cosmetic facial enhancement with minimal risk and rapid recovery has inspired the field of nonsurgical Skin rejuvenation. Laser Resurfacing was introduced in the 1980s with continuous wave carbon dioxide (CO(2)) Lasers; however, because of a high rate of side effects, including scarring, short-pulse, high-peak power, and rapidly scanned, focused-beam CO(2) Lasers and normal-mode erbium-doped yttrium aluminium garnet Lasers were developed, which remove Skin in a precisely controlled manner. The prolonged 2-week recovery time and small but significant complication risk prompted the development of non-ablative and, more recently, fractional Resurfacing in order to minimize risk and shorten recovery times. Nonablative Resurfacing produces dermal thermal injury to improve rhytides and photodamage while preserving the epidermis. Fractional Resurfacing thermally ablates microscopic columns of epidermal and dermal tissue in regularly spaced arrays over a fraction of the Skin surface. This intermediate approach increases efficacy as compared to nonablative Resurfacing, but with faster recovery as compared to ablative Resurfacing. Neither nonablative nor fractional Resurfacing produces results comparable to ablative Laser Skin Resurfacing, but both have become much more popular than the latter because the risks of treatment are limited in the face of acceptable improvement. At the completion of this learning activity, participants should be familiar with the spectrum of Lasers and light technologies available for Skin Resurfacing, published studies of safety and efficacy, indications, methodologies, side effects, complications, and management.
-
Fractional Resurfacing: New and Improved Laser Skin Resurfacing?
NEJM Journal Watch, 2004Co-Authors: Jeffrey S. Dover, FrcpcAbstract:Because of the high risk-benefit ratio of Laser Skin Resurfacing, less invasive approaches for treating photoaging have been desirable. Nonablative
-
A prospective survey of patient experiences after Laser Skin Resurfacing: results from 2 1/2 years of follow-up.
Archives of dermatology, 2003Co-Authors: R. Sonia Batra, Kenneth A. Arndt, Carolyn I. Jacob, Lori Hobbs, Jeffrey S. DoverAbstract:Background Laser Skin Resurfacing (LSR) is a common cosmetic surgical procedure, yet there are no prospective long-term studies on patients' perceptions of their procedure. Objective To prospectively document patients' subjective experiences after LSR. Design Twenty-seven consecutive patients who underwent combination carbon dioxide/erbium:YAG full-face Laser Resurfacing for acne scarring or photodamage were surveyed at postoperative days 1 and 3, within 1 week, at 3 weeks, 6 weeks, 3 months, and 30 months and asked standardized questions. Setting Referral-based academic practice. Results One day after LSR, 10 patients (37%) were concerned about the outcome, and 3 (11%) considered it a "terrible" experience. At 2.7 days after the procedure, 23 patients (85%) would recommend LSR, and after 3.7 days, 24 (89%) would have the procedure again. At 3 months, the patients' mean rating of appearance was 2.3 (0-3 scale), and all 27 (100%) felt that their appearance had been improved by LSR. After 30 months, 18 patients (75%) would recommend the procedure, 17 (71%) would have LSR again, 21 (88%) felt that their appearance was improved, and final appearance was rated 1.8 (0-3 scale). Patients undergoing LSR to treat acne scarring were as satisfied as patients treated for photodamage. Conclusions Data on the evolution of patient perspective after LSR can improve patient preparation. This may help the surgeon and patient achieve shared, realistic expectations for the postoperative period and for long-term results.
Tina S. Alster - One of the best experts on this subject based on the ideXlab platform.
-
Evolution of Laser Skin Resurfacing: from scanning to fractional technology.
Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.], 2014Co-Authors: Arif Aslam, Tina S. AlsterAbstract:BACKGROUND Laser Skin Resurfacing was popularized for photoaged and scarred Skin 2 decades ago. Since then, several technologic advancements have led to a new generation of delivery systems that produce excellent clinical outcomes with reduced treatment risks and faster recovery times. OBJECTIVES To review the evolution of Laser Skin Resurfacing from pulsed and scanned infrared Laser technology to the latest techniques of nonablative and ablative fractional photothermolysis. MATERIALS AND METHODS All published literature regarding Laser Skin Resurfacing was analyzed and collated. RESULTS A comprehensive review of Laser Skin Resurfacing was outlined and future developments in the field of fractionated Laser Skin treatment were introduced. CONCLUSION Laser Skin Resurfacing has evolved such that excellent clinical outcomes in photodamaged and scarred Skin are achieved with rapid wound healing. As newer devices are developed, the applications of this technology will have a dramatic effect on the delivery of medical and aesthetic dermatology.
-
fractionated Laser Skin Resurfacing treatment complications a review
Dermatologic Surgery, 2010Co-Authors: Andrei I. Metelitsa, Tina S. AlsterAbstract:BACKGROUNDFractional photothermolysis represents a new modality of Laser Skin Resurfacing that was developed to provide a successful clinical response while minimizing postoperative recovery and limiting treatment complications.OBJECTIVESTo review all of the reported complications that develop as a
-
Fractionated Laser Skin Resurfacing Treatment Complications: A Review
Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.], 2010Co-Authors: Andrei I. Metelitsa, Tina S. AlsterAbstract:Fractional photothermolysis represents a new modality of Laser Skin Resurfacing that was developed to provide a successful clinical response while minimizing postoperative recovery and limiting treatment complications. To review all of the reported complications that develop as a result of fractional ablative and nonablative Laser Skin Resurfacing. A literature review was based on a MEDLINE search (1998-2009) for English-language articles related to Laser treatment complications and fractional Skin Resurfacing. Articles presenting the highest level of evidence and the most recent reports were preferentially selected. Complications with fractional Laser Skin Resurfacing represent a full spectrum of severity and can be longlasting. In general, a greater likelihood of developing post-treatment complications is seen in sensitive cutaneous areas and in patients with intrinsically darker Skin phototypes or predisposing medical risk factors. Although the overall rate of complications associated with fractional Laser Skin Resurfacing is much lower than with traditional ablative techniques, recent reports suggest that serious complications can develop. An appreciation of all of the complications associated with fractional Laser Skin Resurfacing is important, especially given that many of them can be potentially prevented. The authors have indicated no significant interest with commercial supporters.
-
Fraxel Laser Indications and Long-Term Follow-Up
Aesthetic surgery journal, 2008Co-Authors: Elizabeth L. Tanzi, Rungsima Wanitphakdeedecha, Tina S. AlsterAbstract:Fractional photothermolysis, based on creating spatially precise microscopic thermal wounds, is performed using a 1550-nm erbium fiber Laser that targets water-containing tissue to effect the photocoagulation of narrow, sharply defined columns of Skin known as microscopic thermal zones. According to the authors, Fraxel Resurfacing has been shown to be both safe and effective for facial and nonfacial photodamage, atrophic acne scars, hypopigmented scars, and dyspigmentation. Because only a fraction of the Skin is treated during a single session, a series (typically 3 to 6 treatments) of fractional Resurfacing at 2- to 4-week intervals is required for the best clinical improvement. It is the authors' experience that a series of Fraxel treatments can achieve a similar clinical result for atrophic scars compared with traditional ablative Laser Skin Resurfacing. However, the improvement seen after a series of Fraxel treatments for perioral laxity and rhytides often falls short of the impressive results that can be achieved with ablative Laser Skin Resurfacing.
-
Re: Improvement of Dermatochalasis and Periorbital Rhytids with a High-Energy Pulsed CO2 Laser
Dermatologic Surgery, 2004Co-Authors: Tina S. Alster, Supriya G. BellewAbstract:BACKGROUNDUpper eyelid dermatochalasis is typically treated with excisional blepharoplasty. The role of the CO2 Laser previously had been confined to that of a vaporizing, incisional, or hemostatic tool. Over the past several years, however, ablative CO2 Laser Skin Resurfacing has been popularized a
Kenneth A. Arndt - One of the best experts on this subject based on the ideXlab platform.
-
Fractional Laser Skin Resurfacing.
Journal of drugs in dermatology : JDD, 2012Co-Authors: Macrene Alexiades-armenakas, Jeffrey S. Dover, Kenneth A. ArndtAbstract:Laser Skin Resurfacing (LSR) has evolved over the past 2 decades from traditional ablative to fractional nonablative and fractional ablative Resurfacing. Traditional ablative LSR was highly effective in reducing rhytides, photoaging, and acne scarring but was associated with significant side effects and complications. In contrast, nonablative LSR was very safe but failed to deliver consistent clinical improvement. Fractional LSR has achieved the middle ground; it combined the efficacy of traditional LSR with the safety of nonablative modalities. The first fractional Laser was a nonablative erbium-doped yttrium aluminum garnet (Er:YAG) Laser that produced microscopic columns of thermal injury in the epidermis and upper dermis. Heralding an entirely new concept of Laser energy delivery, it delivered the Laser beam in microarrays. It resulted in microscopic columns of treated tissue and intervening areas of untreated Skin, which yielded rapid reepithelialization. Fractional delivery was quickly applied to ablative wavelengths such as carbon dioxide, Er:YAG, and yttrium scandium gallium garnet (2,790 nm), providing more significant clinical outcomes. Adjustable Laser parameters, including power, pitch, dwell time, and spot density, allowed for precise determination of percent surface area, affected penetration depth, and clinical recovery time and efficacy. Fractional LSR has been a significant advance to the Laser field, striking the balance between safety and efficacy.
-
the spectrum of Laser Skin Resurfacing nonablative fractional and ablative Laser Resurfacing
Journal of The American Academy of Dermatology, 2008Co-Authors: Macrene Alexiadesarmenakas, Jeffrey S. Dover, Kenneth A. ArndtAbstract:The drive to attain cosmetic facial enhancement with minimal risk and rapid recovery has inspired the field of nonsurgical Skin rejuvenation. Laser Resurfacing was introduced in the 1980s with continuous wave carbon dioxide (CO 2 ) Lasers; however, because of a high rate of side effects, including scarring, short-pulse, high-peak power, and rapidly scanned, focused-beam CO 2 Lasers and normal-mode erbium-doped yttrium aluminium garnet Lasers were developed, which remove Skin in a precisely controlled manner. The prolonged 2-week recovery time and small but significant complication risk prompted the development of non-ablative and, more recently, fractional Resurfacing in order to minimize risk and shorten recovery times. Nonablative Resurfacing produces dermal thermal injury to improve rhytides and photodamage while preserving the epidermis. Fractional Resurfacing thermally ablates microscopic columns of epidermal and dermal tissue in regularly spaced arrays over a fraction of the Skin surface. This intermediate approach increases efficacy as compared to nonablative Resurfacing, but with faster recovery as compared to ablative Resurfacing. Neither nonablative nor fractional Resurfacing produces results comparable to ablative Laser Skin Resurfacing, but both have become much more popular than the latter because the risks of treatment are limited in the face of acceptable improvement. Learning objectives At the completion of this learning activity, participants should be familiar with the spectrum of Lasers and light technologies available for Skin Resurfacing, published studies of safety and efficacy, indications, methodologies, side effects, complications, and management.
-
The spectrum of Laser Skin Resurfacing: Nonablative, fractional, and ablative Laser Resurfacing
Journal of the American Academy of Dermatology, 2008Co-Authors: Macrene Alexiades-armenakas, Jeffrey S. Dover, Kenneth A. ArndtAbstract:The drive to attain cosmetic facial enhancement with minimal risk and rapid recovery has inspired the field of nonsurgical Skin rejuvenation. Laser Resurfacing was introduced in the 1980s with continuous wave carbon dioxide (CO(2)) Lasers; however, because of a high rate of side effects, including scarring, short-pulse, high-peak power, and rapidly scanned, focused-beam CO(2) Lasers and normal-mode erbium-doped yttrium aluminium garnet Lasers were developed, which remove Skin in a precisely controlled manner. The prolonged 2-week recovery time and small but significant complication risk prompted the development of non-ablative and, more recently, fractional Resurfacing in order to minimize risk and shorten recovery times. Nonablative Resurfacing produces dermal thermal injury to improve rhytides and photodamage while preserving the epidermis. Fractional Resurfacing thermally ablates microscopic columns of epidermal and dermal tissue in regularly spaced arrays over a fraction of the Skin surface. This intermediate approach increases efficacy as compared to nonablative Resurfacing, but with faster recovery as compared to ablative Resurfacing. Neither nonablative nor fractional Resurfacing produces results comparable to ablative Laser Skin Resurfacing, but both have become much more popular than the latter because the risks of treatment are limited in the face of acceptable improvement. At the completion of this learning activity, participants should be familiar with the spectrum of Lasers and light technologies available for Skin Resurfacing, published studies of safety and efficacy, indications, methodologies, side effects, complications, and management.
-
A prospective survey of patient experiences after Laser Skin Resurfacing: results from 2 1/2 years of follow-up.
Archives of dermatology, 2003Co-Authors: R. Sonia Batra, Kenneth A. Arndt, Carolyn I. Jacob, Lori Hobbs, Jeffrey S. DoverAbstract:Background Laser Skin Resurfacing (LSR) is a common cosmetic surgical procedure, yet there are no prospective long-term studies on patients' perceptions of their procedure. Objective To prospectively document patients' subjective experiences after LSR. Design Twenty-seven consecutive patients who underwent combination carbon dioxide/erbium:YAG full-face Laser Resurfacing for acne scarring or photodamage were surveyed at postoperative days 1 and 3, within 1 week, at 3 weeks, 6 weeks, 3 months, and 30 months and asked standardized questions. Setting Referral-based academic practice. Results One day after LSR, 10 patients (37%) were concerned about the outcome, and 3 (11%) considered it a "terrible" experience. At 2.7 days after the procedure, 23 patients (85%) would recommend LSR, and after 3.7 days, 24 (89%) would have the procedure again. At 3 months, the patients' mean rating of appearance was 2.3 (0-3 scale), and all 27 (100%) felt that their appearance had been improved by LSR. After 30 months, 18 patients (75%) would recommend the procedure, 17 (71%) would have LSR again, 21 (88%) felt that their appearance was improved, and final appearance was rated 1.8 (0-3 scale). Patients undergoing LSR to treat acne scarring were as satisfied as patients treated for photodamage. Conclusions Data on the evolution of patient perspective after LSR can improve patient preparation. This may help the surgeon and patient achieve shared, realistic expectations for the postoperative period and for long-term results.
-
Evaluation of a silicone occlusive dressing after Laser Skin Resurfacing.
Archives of dermatology, 2001Co-Authors: R. Sonia Batra, Kenneth A. Arndt, Richard J. Ort, Carolyn I. Jacob, Lori Hobbs, Jeffrey S. DoverAbstract:Background Closed dressings are thought to promote postoperative wound healing after Laser Skin Resurfacing; however, quantitative data are lacking. Objective To compare postoperative healing after combination carbon dioxide and erbium:YAG full-face Laser Skin Resurfacing in patients who were treated with a silicone occlusive dressing (Silon-TSR; Bio Med Sciences, Inc, Bethlehem, Pa) vs open-wound care consisting of soaks and ointment application. Design Thirty-five patients with closed dressings compared retrospectively with 35 control subjects with open-wound care. In a prospective evaluation, 27 patients with closed dressings were then compared with 27 historical controls matched by age, sex, Skin type, and treatment technique. Erythema, crusting, swelling, pain, pruritus, purpura, long-term complications, and dressing comfort were evaluated. Setting Referral-based academic practice. Results Prospectively, closed-dressing and open-wound care groups differed significantly in maximum erythema severity (1.8 vs 2.0 on a scale of 0-3; P = .03), noticeable erythema duration (15.4 vs 31.1 days; P = .04), and time until complete erythema resolution (41.8 vs 96.1 days; P = .02). Swelling resolution was more rapid in the dressing group (12.1 vs 29.5 days; P = .02). Crusting was limited to uncovered areas in the dressing group, and crusting duration was shorter (5.0 vs 9.1 days; P Conclusions Occlusive silicone dressing application decreases immediate postoperative morbidity with significantly reduced severity and duration of erythema and decreased duration of swelling and crusting. Long-term results and complication rates remain unchanged.
David H. Mcdaniel - One of the best experts on this subject based on the ideXlab platform.
-
Variable pulse erbium:YAG Laser Skin Resurfacing of perioral rhytides and side-by-side comparison with carbon dioxide Laser†
Lasers in surgery and medicine, 2000Co-Authors: John Newman, Jeff Lord, Keith Ash, David H. McdanielAbstract:Laser Resurfacing of facial rhytides has become a popular treatment option for many patients with wrinkles, photoaging, and acne scarring. Laser wavelength/pulse duration options and new techniques continue to shorten the healing phase associated with Laser Skin Resurfacing while maintaining clinical efficacy. Variable pulse erbium:YAG (Er:YAG) Laser systems are now available that offer the surgeon the ability to vary the Er:YAG pulse duration from a pulse that is primarily ablative to one that is more thermal. The objective of this study was to evaluate the histologic effects created with a variable pulse Er:YAG Laser. To study prospectively the clinical effects on upper lip rhytides with a variable pulse Er:YAG Laser when compared side by side with pulsed carbon dioxide (CO(2)) Laser Resurfacing. Forty-two treatment sites on 21 patients were randomized and evaluated after treatment of the upper lip region with CO(2) Laser Resurfacing on one side and a variable pulse Er:YAG Laser on the other. Patient diaries were maintained to assess erythema, crusting, pain, and pigmentary changes. Blinded objective grading of improvement was performed. Chromometer measurements were obtained to analyze erythema. The variable pulse Er:YAG Laser treatment reduced the duration of crusting on average from 7.7 days with CO(2) to 3.4 days. Chromometer measurements noted decreased postoperative erythema. Grading by physicians in a blinded manner showed 63% improvement for the CO(2) treatment site and 48% improvement in the variable pulse Er:YAG site. No cases of permanent hyperpigmentation, hypopigmentation, or scarring occurred. The variable pulse Er:YAG Laser Resurfacing is a safe and effective Resurfacing tool, which combines ablative and thermal modalities. The protocol used in this study approaches but does not equal the results we have traditionally seen with CO(2) Laser Resurfacing. Copyright 2000 Wiley-Liss, Inc.
-
variable pulse erbium yag Laser Skin Resurfacing of perioral rhytides and side by side comparison with carbon dioxide Laser
Lasers in Surgery and Medicine, 2000Co-Authors: John Newman, Jeff Lord, K O Ash, David H. McdanielAbstract:Background and Objective Laser Resurfacing of facial rhytides has become a popular treatment option for many patients with wrinkles, photoaging, and acne scarring. Laser wavelength/pulse duration options and new techniques continue to shorten the healing phase associated with Laser Skin Resurfacing while maintaining clinical efficacy. Variable pulse erbium:YAG (Er:YAG) Laser systems are now available that offer the surgeon the ability to vary the Er:YAG pulse duration from a pulse that is primarily ablative to one that is more thermal. The objective of this study was to evaluate the histologic effects created with a variable pulse Er:YAG Laser. To study prospectively the clinical effects on upper lip rhytides with a variable pulse Er:YAG Laser when compared side by side with pulsed carbon dioxide (CO2) Laser Resurfacing. Study Design/Materials and Methods Forty-two treatment sites on 21 patients were randomized and evaluated after treatment of the upper lip region with CO2 Laser Resurfacing on one side and a variable pulse Er:YAG Laser on the other. Patient diaries were maintained to assess erythema, crusting, pain, and pigmentary changes. Blinded objective grading of improvement was performed. Chromometer measurements were obtained to analyze erythema. Results The variable pulse Er:YAG Laser treatment reduced the duration of crusting on average from 7.7 days with CO2 to 3.4 days. Chromometer measurements noted decreased postoperative erythema. Grading by physicians in a blinded manner showed 63% improvement for the CO2 treatment site and 48% improvement in the variable pulse Er:YAG site. No cases of permanent hyperpigmentation, hypopigmentation, or scarring occurred. Conclusion The variable pulse Er:YAG Laser Resurfacing is a safe and effective Resurfacing tool, which combines ablative and thermal modalities. The protocol used in this study approaches but does not equal the results we have traditionally seen with CO2 Laser Resurfacing. Lasers Surg. Med. 26:208–214, 2000 © 2000 Wiley-Liss, Inc.
Boris Majaron - One of the best experts on this subject based on the ideXlab platform.
-
Er:YAG Laser Skin Resurfacing using repetitive long-pulse exposure and cryogen spray cooling: II. Theoretical analysis.
Lasers in surgery and medicine, 2001Co-Authors: Boris Majaron, Kristen M. Kelly, Wim Verkruysse, John Stuart NelsonAbstract:To analyze the effects of Laser pulse duration and cryogen spray cooling (CSC) on epidermal damage and depth of collagen coagulation in Skin Resurfacing with repetitive Er:YAG Laser irradiation. Evolution of temperature field in Skin is calculated using a simple one-dimensional model of sub-ablative pulsed Laser exposure and CSC. The model is solved numerically for Laser pulse durations of 150 and 600 microsec, and 6 msec cryogen spurts delivered just prior to ("pre-cooling"), or during and after ("post-cooling") the 600 microsec Laser pulse. The model indicates a minimal influence of pulse duration on the extent of thermal effect in dermis, but less epidermal damage with 600 microsec pulses as compared to 150 microsec at the same pulse fluence. Application of pre- or post-cooling reduces the peak surface temperature after Laser exposure and accelerates its relaxation toward the base temperature to a different degree. However, the temperature profile in Skin after 50 msec is in either example very similar to that after a lower-energy Laser pulse without CSC. When applied in combination with repetitive Er:YAG Laser exposure, CSC strongly affects the amount of heat available for dermal coagulation. As a result, CSC may not provide spatially selective epidermal protection in Er:YAG Laser Skin Resurfacing. Copyright 2001 Wiley-Liss, Inc.
-
Er:YAG Laser Skin Resurfacing Using Repetitive Long-Pulse Exposure and Cryogen Spray Cooling: I. Histological Study
Lasers in surgery and medicine, 2001Co-Authors: Boris Majaron, Kristen M. Kelly, Hyle Park, Wim Verkruysse, J. Stuart NelsonAbstract:To evaluate histologically the characteristics of repetitive Er:YAG Laser exposure of Skin in combination with cryogen spray cooling (CSC), and its potential as a method of Laser Skin Resurfacing. Rat Skin was irradiated in vivo with sequences of 10 Er:YAG Laser pulses (repetition rate 20 Hz, pulse duration 150 or 550 micros, single-pulse fluence 1.3-5.2 J/cm(2)). In some examples, CSC was applied to reduce epidermal injury. Histologic evaluation was performed 1 hour, 1 day, 5 days, and 4 weeks post-irradiation. A sequence of ten 550-micros pulses with fluences around 2 J/cm(2) resulted in acute dermal collagen coagulation to a depth of approximately 250 microm, without complete epidermal ablation. CSC improved epidermal preservation, but also diminished the coagulation depth. Four weeks after irradiation, neo-collagen formation was observed to depths in excess of 100 microm. Dermal collagen coagulation and neo-collagen formation to depths similar to those observed after CO(2) Laser Resurfacing can be achieved without complete ablation of the epidermis by rapidly stacking long Er:YAG Laser pulses. Application of CSC does not offer significant epidermal protection for a given dermal coagulation depth. Copyright 2001 Wiley-Liss, Inc.
-
er yag Laser Skin Resurfacing using repetitive long pulse exposure and cryogen spray cooling ii theoretical analysis
Lasers in Surgery and Medicine, 2001Co-Authors: Boris Majaron, Kristen M. Kelly, Wim Verkruysse, J. Stuart NelsonAbstract:Background and Objective To analyze the effects of Laser pulse duration and cryogen spray cooling (CSC) on epidermal damage and depth of collagen coagulation in Skin Resurfacing with repetitive Er:YAG Laser irradiation. Study Design/Materials and Methods Evolution of temperature field in Skin is calculated using a simple one-dimensional model of sub-ablative pulsed Laser exposure and CSC. The model is solved numerically for Laser pulse durations of 150 and 600 μsec, and 6 msec cryogen spurts delivered just prior to (“pre-cooling”), or during and after (“post-cooling”) the 600 μsec Laser pulse. Results The model indicates a minimal influence of pulse duration on the extent of thermal effect in dermis, but less epidermal damage with 600 μsec pulses as compared to 150 μsec at the same pulse fluence. Application of pre- or post-cooling reduces the peak surface temperature after Laser exposure and accelerates its relaxation toward the base temperature to a different degree. However, the temperature profile in Skin after 50 msec is in either example very similar to that after a lower-energy Laser pulse without CSC. Conclusions When applied in combination with repetitive Er:YAG Laser exposure, CSC strongly affects the amount of heat available for dermal coagulation. As a result, CSC may not provide spatially selective epidermal protection in Er:YAG Laser Skin Resurfacing. Lasers Surg. Med. 28:131–137, 2001. © 2001 Wiley-Liss, Inc.
-
Modeling of thermal effects in Er:YAG Laser Skin Resurfacing
Medical Applications of Lasers in Dermatology Ophthalmology Dentistry and Endoscopy, 1997Co-Authors: Boris Majaron, Primoz Plestenjak, Matjaz LukacAbstract:The influence of Er:YAG Laser pulse fluence and duration on temperature profile development, coagulation depth and the ablation threshold in Skin Resurfacing is analyzed using an original 1D numerical model. The model is focused on the role of mechanical properties of the treated tissue, such as elastic modulus and tensile strength. It combines a thermodynamic model of overhead tissue water with the response of surrounding elastic medium to the resulting pressure increase. Diffusion of dissipated heat is treated in one dimension for the case of isolated tissue surface. Additionally, the nonlinear protein denaturation process is modeled as usual. The results show how the pulse duration influences the depth of heat-affected layer in mid-IR Laser Skin Resurfacing.
