Left, Full-face anteroposterior view of a patient prior to combined erbium:YAG and carbon dioxide laser skin resurfacing. Right, The same patient 9 days after combined erbium:YAG and carbon dioxide laser full-face skin resurfacing demonstrating reepithelialization of the epidermis and slight residual erythema.
Left, Full-face anteroposterior view of a patient prior to carbon dioxide laser skin resurfacing. Right, The same patient 14 days after full-face laser resurfacing with only the carbon dioxide laser showing marked erythema compared with the patient treated with the combined laser protocol (Figure 1). This patient's erythema resolved 12 weeks after laser skin resurfacing.
Left, An eyelid skin biopsy specimen 9 days after skin resurfacing with the erbium:YAG and carbon dioxide laser reveals complete reepithelialization. Viable cells are retained in the superficial papillary dermis corresponding to the middle level (arrowhead) of the hair follicle (hematoxylin-eosin, original magnification ×20). Right, Lower magnification of an eyelid skin biopsy specimen 14 days after skin resurfacing with only the carbon dioxide laser reveals coagulative dermal damage and necrosis extending deeper than the dermal remodeling seen in the combined laser protocol (Figure 3, left). The zone of coagulative necrosis (within small arrowheads), manifesting as a loss of cells and eosinophilia, extends up to the lower level of a hair follicle (large arrowhead) that is located deeper in the reticular dermis than the hair follicle seen in Figure 3, left (hematoxylin-eosin, original magnification ×4).
Millman AL, Mannor GE. Combined Erbium:YAG and Carbon Dioxide Laser Skin Resurfacing. Arch Facial Plast Surg. 1999;1(2):112-116. doi:10.1001/archfaci.1.2.112
From the Department of Ophthalmology, Mount Sinai Medical Center (Drs Millman and Mannor), The New York Eye and Ear Infirmary (Dr Millman), New York, and the Ophthalmology Section, Department of Surgery, Bronx VA Hospital, Bronx (Dr Mannor), NY.
Objective To compare clinical and histological results of 2 different protocols for cosmetic laser skin resurfacing.
Design Masked comparison of 2 cohort groups.
Patients Forty-eight carefully selected patients who met specific inclusion and exclusion criteria for cosmetic laser skin resurfacing. Age, sex, and skin type were matched in both groups.
Interventions Twenty-five patients had undergone cosmetic skin resurfacing with 2 impacts of a carbon dioxide laser. Another 23 patients underwent a different protocol involving 2 initial impacts of an erbium:YAG laser to ablate the epidermis followed by a single impact with a carbon dioxide laser. Skin punch biopsy specimens were obtained 1 to 2 weeks after the procedure in both groups of patients.
Main Outcome Measures Time to reepithelialization, duration of erythema, and patient acceptance were compared among 2 patient groups via Student t test. Patients were examined daily until reepithelialization, then weekly for 6 weeks, and then monthly for 6 months.
Results Mean skin reepithelialization time was 7 days (range, 4-9 days) in the combined laser group vs 12 days (range, 9-15 days) in the carbon dioxide laser–only group (P=.04). Mean duration of erythema was 2.5 weeks (range, 1.5-3 weeks) in the combined laser group vs 7 weeks (range, 5-13 weeks) in the carbon dioxide laser–only group (P=.02). All 23 patients (100%) in the combined group but only 15 (60%) of 25 in the carbon dioxide laser–only group were willing to repeat their cosmetic laser surgery (P=.04). There were greater and deeper coagulative changes in the dermis of patients in the carbon dioxide laser–only group compared with those of patients in the combined laser group.
Conclusions The combined laser protocol showed less significant clinical and histological morbidity than the carbon dioxide laser–only protocol. Patients preferred the combined protocol. Combining these 2 lasers is a safe and patient-friendly alternative to using only the carbon dioxide laser.
CURRENT LASER options for aesthetic skin resurfacing include the carbon dioxide laser and the more recently developed erbium:YAG laser. Each of these lasers possesses different relative advantages and disadvantages. The carbon dioxide super-pulse laser was the first laser to cosmetically resurface skin. It emits infrared light at 10.6 µm and is highly absorbed by water.1-3 Depending on the specific type of carbon dioxide laser employed, each laser impact ablates 20 to 100 µm of skin and leaves an additional 20- to 40-µm zone of thermal damage.1-4 With each subsequent laser impact, the amount of tissue ablated may increase (100-200 µm), but unfortunately, the zone of thermal damage also increases (40-150 µm).4-9 Recent clinical experience documents a 10- to 14-day reepithelialization duration with postoperative erythema that lasts 3 to 6 months.9-26
The erbium:YAG laser emits light at a wavelength of 2.94 µm and is 16 times more highly absorbed by water than the carbon dioxide laser light.27-29 The erbium:YAG laser's higher water absorption results in a much more superficial penetration and ablation of tissue than the carbon dioxide laser. The erbium:YAG laser ablates 10 to 40 µm of skin per impact and leaves only 10-20 µm of thermal damage.30-32 Most importantly, with each subsequent laser impact, the zone of thermal damage does not increase, as it does for the carbon dioxide laser, but remains the same. The erbium:YAG laser's reduced zone of thermal damage compared with the carbon dioxide laser correlates with less morbidity than with the carbon dioxide laser. Skin treated with the erbium:YAG laser achieves reepithelialization within 2 to 7 days and its erythema resolves within 2 to 4 weeks.32-35
The differing biophysical properties of these 2 lasers produce different clinical effects. Because the carbon dioxide laser penetrates and ablates deeper, it also causes greater associated thermal damage than the erbium:YAG laser. Therefore, with erbium:YAG laser resurfacing, skin reepithelialization is quicker and postoperative erythema is shorter. However, the deeper tissue penetration of carbon dioxide laser light may have an important clinical application. The carbon dioxide laser may be better able to produce dermal remodeling than the erbium:YAG laser. Dermal remodeling may be necessary for achieving the youthful aesthetic result following laser skin resurfacing.36-38
The aim of combining these 2 distinct lasers is to minimize their relative disadvantages while maximizing their relative advantages. The erbium:YAG laser is used to remove the epidermis and to enter the superficial dermis. The carbon dioxide laser is carefully restricted to only remodeling the dermis. The large zone of thermal damage produced by the carbon dioxide laser is minimized because this laser is used for only 1 impact and is confined to the dermis where its potentially beneficial effect on dermal remodeling (and cosmetic improvement) is retained. By using both of these lasers at the same treatment session, we hope to demonstrate a satisfactory cosmetic skin tightening and wrinkle improvement while diminishing perioperative morbidity.
All patients gave informed consent after discussion of therapy and alternative treatments. Patients were at least 18 years old and without a history of isotretinoin use (Accutane; Hoffmann-LaRoche, Nutley, NJ), acne, herpes infection, hepatitis infection, human immunodeficiency virus infection, viral warts, estrogen use, facial irradiation, hypertrophic scarring, smoking, vitiligo, bleeding disorders, and notable skin or medical disease. Patients with Fitzpatrick skin type of greater than III were excluded. Patients were pretreated with a 2% hydroquinone (Melanex; Neutrogena, Los Angeles, Calif) cream and a broad-spectrum (UV-A and UV-B) sunblock with a sun protective factor of 15 for 6 weeks prior to treatment.
At surgery, each patient received regional nerve block with up to 10 mL of 2% lidocaine with 1:200,000 epinephrine in addition to topical ophthalmic anesthesia (Ophthaine; Alcon, Dallas, Tex). Nonreflective burnished instruments and eye shields (Byron Medical, Tucson, Ariz) were employed with a filtered vacuum smoke evacuator (ESC Medical Corporation, Allendale, NJ). After standard surgical prepping and installation of protective eye shields, laser resurfacing of the periorbital region was begun with the surgeon wearing ×2.5 magnifying surgical loupes (Designs for Vision, Delray, Fla). An erbium:YAG laser (Derma 20; ESC Medical Corporation) set at 1 J and 10 Hz was delivered via a 3-mm collimated handpiece. The epidermis was treated with 30% overlap and slight feathering of the edges of the untreated skin. Pinpoint bleeding in the superficial papillary dermis was evident after the second impact. A carbon dioxide super-pulse laser (Novapulse SureScan; ESC Medical Corporation) set at 9 W power or 300 mJ was delivered via a computer pattern generator over the dermis previously treated with 2 erbium:YAG laser impacts. After the single carbon dioxide laser impact, a moist gauze pad gently removed coagulated debris.
An occlusive dressing (Flexan; Porex Surgical, College Park, Ga) was placed on the treated area and removed 3 days later. Patients received an antibiotic (cephalexin, 250 mg twice daily) and antiviral medication (acyclovir, 400 mg 3 times daily) beginning on the day of surgery and lasting until full reepithelialization occurred. Skin lubrication was continued for 2 weeks after the procedure. Patients were examined daily until reepithelialization, then weekly for 6 weeks, and then monthly for 6 months. After complete reepithelialization, treatment with the preoperative skin care regimen, along with 0.025% tretinoin cream (Retin-A; Ortho Pharmaceuticals, Raritan, NJ), was restarted as soon as patients were able to tolerate skin medication.
Patients underwent standard external photography at each visit. An oculoplastic surgeon (G.E.M.) who was masked to the treatment parameters reviewed their photographs and charts. Clinical outcomes monitored included duration of reepithelialization, course of erythema, and final aesthetic results. These outcomes were compared with those in a prior group of 25 patients who underwent skin resurfacing with only the carbon dioxide laser (2 impacts at the same laser parameters) without any erbium:YAG laser treatment. The Student 2-tailed t test was used for all comparisons between these 2 groups of patients. All patients were asked whether they would repeat their laser surgery treatment, and if not, why.
Several patients gave informed consent for skin punch biopsy from 1 to 2 weeks following their laser surgery. The skin specimens obtained were placed in 10% formalin, processed with hematoxylin-eosin stain, and evaluated by an eye pathology laboratory without knowledge of the specific treatment regimen.
The minimum follow-up for each patient was 6 months (range, 6-11 months). The age and sex distributions were similar in the 2 patient groups (Table 1). Also, there was no difference in the distribution of Fitzpatrick skin types among both groups (Table 1). Within 6 months' minimum follow-up, no patient experienced any adverse effects such as skin infection, scarring, hypopigmentation, postinflammatory hyperpigmentation, or wound dehiscence (Table 1, Figure 1 and Figure 2). Mean reepithelialization lasted 7 days (range, 4-9 days) in the combined laser group vs 12 days (range, 9-15 days) in the carbon dioxide laser–only group (P=.04). Similarly, mean postoperative erythema lasted 2.5 weeks (range, 1.5-3 weeks) in the combined laser group vs 7 weeks (range, 5-13 weeks) in the carbon dioxide laser–only group (P=.02). Of note, skin tightening and amelioration of rhytids was achieved in both groups (Figure 1 and Figure 2).
All 23 patients in the combined laser treatment group were willing to undergo the procedure again (Table 1). However, 10 (40%) of 25 of the carbon dioxide laser–only treated group expressed ambivalence because of the prolonged duration of cutaneous reepithelialization and erythema (P=.04).
Histopathologic analysis revealed accurate ablation of the epidermis with 2 impacts of the erbium:YAG laser and proper penetration of the superficial papillary dermis with the carbon dioxide laser. Histopathologic evaluation of those in the combined laser treatment group demonstrated minimal superficial papillary dermal remodeling without much necrosis, while patients treated with only the carbon dioxide laser demonstrated extensive coagulative necrosis extending to the deep reticular dermis (Figure 3, Table 1).
We have demonstrated similar efficacy with reduced clinical and histopathologic morbidity when combining treatment with the erbium:YAG and carbon dioxide lasers in facial skin resurfacing. The time to reepithelialization and the duration of erythema is significantly shorter in the combined laser protocol compared with the group treated with 2 impacts of only the carbon dioxide laser. Histopathologic analysis confirms the clinical results by documenting less collateral thermal damage from the combined laser protocol. Aesthetic outcome including tightening of the skin and amelioration of wrinkles did not differ significantly in each group. The deeper penetration and greater dermal remodeling from the carbon dioxide laser might be useful for patients with extremely deep wrinkles. Nonetheless, our patients were satisfied with their final cosmetic outcome, and none of the patients in the combined laser group was less satisfied than their carbon dioxide laser–only counterparts. Indeed, because of its reduced morbidity compared with the carbon dioxide laser–only protocol, the combined laser protocol was preferred by more patients than the carbon dioxide laser–only protocol.
At this time, the exact mechanism of skin tightening and rhytid improvement is unclear. Studies suggest that collagen denaturation, coagulation, and shrinkage are important.36-38 The role of new collagen formation and elastic fiber deposition remains to be elucidated. The ideal resurfacing laser protocol should minimize morbidity such as duration of erythema and reepithelialization while maximizing the aesthetic outcome via dermal remodeling. Currently, these 2 goals appear to require different and competing effects. Morbidity is minimized by precise and delicate tissue ablation. However, cosmetic improvement seems to require greater dermal heat absorption than that delivered by the most precise laser light absorption.
Cosmetic laser skin resurfacing has drawn substantial attention in the lay press and media.39 Rigorous analysis of laser treatment protocols is necessary to continue to improve our techniques. Further study of the precise biochemical and biophysical changes in the skin will be necessary to fully explain the mechanism of skin tightening and rejuvenation. At this time, the combined laser protocol described herein appears relatively effective, safe, and patient friendly.
Accepted for publication February 9, 1999.
Reprints: Geva Mannor, MD, MPH, Department of Ophthalmology–Box 1183, Mount Sinai Medical Center, 1 Gustave L. Levy Pl, New York, NY 10029 (e-mail: email@example.com).