Eyelid resurfacing

Potent Periorbital Fractionated CO2 Laser Resurfacing

BACKGROUND

The aged face results from a culmination of skin changes, gravitational descent, and volume loss. Surgical interventions in the periorbital region are beneficial for addressing these 3 factors. Despite this, studies describing CO2 laser safety settings are lacking.

OBJECTIVE

There is no present consensus on ideal periorbital CO2 laser; therefore, this study evaluates the safety of periorbital laser resurfacing as an adjunct to lower blepharoplasty using robust settings.

MATERIALS AND METHODS

A retrospective review was performed of all patients who underwent bilateral lower blepharoplasty with adjunctive periorbital (upper and lower eyelid) fractionated CO2 laser resurfacing from 2013 to 2018 performed by a single oculoplastic surgeon.

RESULTS

Fifty-nine patients were included. Six patients experienced side effects including postinflammatory hyperpigmentation, (3/59, 5.1%), prolonged superficial excoriations (1/59, 1.7%), prolonged hyperemia (1/59, 1.7%), and lower eyelid retraction requiring lower eyelid recession (1/59, 1.7%). None of the patients developed postoperative infection. All patient expressed satisfaction at their final postoperative visit.

CONCLUSION

CO2 laser resurfacing, even with robust settings, is a safe and effective adjunct to lower blepharoplasty.

Investigation of laser pulsing parameters' importance in Er:YAG laser skin ablation: a theoretical study conducted via newly developed thermo-mechanical ablation model

Objective: Importance of laser pulsing parameters and tissue's mechanical properties in the Er:YAG laser skin-tissue ablation is not adequately understood. The goal here was to develop a computational model that incorporates skin tissue's mechanical properties to investigate the influence of Er:YAG laser pulsing parameters on tissue ablation and coagulation. Methods: Tissue's mechanical properties were incorporated by modeling ablation as a tissue water vaporization occurring under elevated pressures that depend on tissue's stress-strain relationships. Tissue deformation was assumed unidirectional; therefore, a one-dimensional model was utilized. Analytical solution and experimental results were used to verify and validate the model. Then, influence of pulse duration (10 µs-2 ms) and fluence (0-30 J cm^-2) on coagulation depth and ablation efficiency was explored. Results: Verification and validation results suggested that the model is acceptably accurate. Minimal effect of pulse duration on coagulation depth was predicted at sub-ablative conditions. At those conditions, coagulation depth increased asymptotically to ∼90 µm with increasing pulse fluence. At ablative conditions, coagulation depth decreased asymptotically to 22-28 µm with increasing pulse irradiance. Ablation efficiency plateaued at high pulse fluences and long pulse durations. Mechanical properties were important as about 50% increase in coagulation depth and 25% decrease in ablation efficiency were predicted when considering the high strain-rate loading effect in comparison with quasi-static loading. Conclusions: Proper tuning of Er:YAG laser pulsing parameters can substantially improve its therapeutic outcomes. The effect of these parameters varies and depends on whether the laser-tissue conditions are ablative or sub-ablative.

The toxic edge-A novel treatment for refractory erythema and flushing of rosacea

PURPOSE

Rosacea is a common, chronic facial skin disease that affects the quality of life. Treatment of facial erythema with intradermal botulinum toxin injection has previously been reported. The primary objective of the study was the safety and efficacy of thermal decomposition of the stratum corneum using a novel non-laser thermomechanical system (Tixel, Novoxel, Israel) to increase skin permeability for Botulinum toxin in the treatment of facial flushing of rosacea.

METHODS

A retrospective review of16 patients aged 23-45 years with Fitzpatrick Skin Types II to IV and facial erythematotelangiectatic rosacea treated by Tixel followed by topical application of 100 U of abobotulinumtoxin. A standardized high-definition digital camera photographed the patients at baseline and 1, 3, and 6 months after the last treatment. Objective and subjective assessments of the patients were done via Mexameter, the Clinicians Erythema Assessment (CEA), and Patients self-assessment (PSA) scores and the dermatology life quality index (DLQI) validated instrument.

RESULTS

The average Maxameter, CEA, and PSA scores at 1, 3, and 6 months were significantly improved compared with baseline (all had a P-value <0.001). DLQI scores significantly improved with an average score of 18.6 at baseline at 6 months after treatment (P < 0.001). Self-rated patient satisfaction was high. There were no motor function side-effects or drooping.

CONCLUSION

Thermal breakage of the stratum corneum using the device to increase skin permeability for botulinum toxin type A in the treatment of facial flushing of rosacea seems both effective and safe. Lasers Surg. Med. © 2018 Wiley Periodicals, Inc.

In-vivo optical imaging of hsp70 expression to assess collateral tissue damage associated with infrared laser ablation of skin

Laser surgical ablation is achieved by selecting laser parameters that remove confined volumes of target tissue and cause minimal collateral damage. Previous studies have measured the effects of wavelength on ablation, but neglected to measure the cellular impact of ablation on cells outside the lethal zone. In this study, we use optical imaging in addition to conventional assessment techniques to evaluate lethal and sublethal collateral damage after ablative surgery with a free-electron laser (FEL). Heat shock protein (HSP) expression is used as a sensitive quantitative marker of sublethal damage in a transgenic mouse strain, with the hsp70 promoter driving luciferase and green fluorescent protein (GFP) expression (hsp70A1-L2G). To examine the wavelength dependence in the mid-IR, laser surgery is conducted on the hsp70A1-L2G mouse using wavelengths targeting water (OH stretch mode, 2.94 microm), protein (amide-II band, 6.45 microm), and both water and protein (amide-I band, 6.10 microm). For all wavelengths tested, the magnitude of hsp70 expression is dose-dependent and maximal 5 to 12 h after surgery. Tissues treated at 6.45 microm have approximately 4x higher hsp70 expression than 6.10 microm. Histology shows that under comparable fluences, tissue injury at the 2.94-microm wavelength was 2x and 3x deeper than 6.45 and 6.10 microm, respectively. The 6.10-microm wavelength generates the least amount of epidermal hyperplasia. Taken together, this data suggests that the 6.10-microm wavelength is a superior wavelength for laser ablation of skin.

Laser blepharoplasty in Asians

Traditional blepharoplasty removes periorbital wrinkles by cutting and stretching the skin. However, this method has a substantial risk of producing ectropion or scleral show. In addition, fine periocular wrinkles may persist because this method does not change skin texture. The pulsed CO2 laser has recently become a primary surgical tool in treating aging eyelids. Periorbital wrinkles vary in depth not only from person to person, but also among different races. Compared with whites, most Asians have a thicker dermis, so more laser passes and a higher power may be required to remove periorbital wrinkles, but concerns about hyperpigmentation and prolonged erythema have limited its use on Asian skin. In this study, 346 patients underwent laser blepharoplasty at the Korea University Medical Center and at Dr Choi's Aesthetic Clinic. They were followed for 12 months on average from September 1995 to September 1999. The CO2 laser was used in resurfacing periorbital wrinkles, transcutaneous skin excision, and transconjunctival blepharoplasty, including fat removal. The authors assessed the benefit of using the UltraPulse CO2 laser in Asian blepharoplasty. They found that 291 patients (84%) had good to excellent results. The incidence of side effects was very low. Prolonged erythema occurred in 19 patients (5%) and hyperpigmentation occurred in 35 patients (10%), but the erythema disappeared spontaneously within 2 months and the hyperpigmentation could be managed readily by the topical use of retinoids and hydroquinone cream. Therefore, the authors conclude that postoperative hyperpigmentation is no longer a problem limiting laser resurfacing in Asian blepharoplasty. The UltraPulse CO2 laser is a safe and effective rejuvenation method for treating aging eyelids in Asians.