Chapter 90 – Esthetic Laser Skin Treatments
MARC S. COHEN
NANCY G. SWARTZ
The medical and surgical treatment of skin appearance has changed dramatically over the past several years. Botulinum neurotoxin (Botox), topical agents, minimally invasive procedures (glycolic peels, intense pulsed light, microdermabrasion), and laser skin resurfacing have captured the imagination of the public and have improved substantially our therapeutic options. The number of treatments to improve the appearance of skin far exceeds that of any other cosmetic procedure. This chapter will focus on the use of the CO2 laser to improve skin texture.
Skin responds to age and sun damage in characteristic ways. With aging, the skin produces less collagen, elastin, and glycosaminoglycans and is less able to respond to injury. Ultraviolet radiation from the sun injures dermal collagen and elastin. The epithelium loses its normal polarity, atypia develops, and pigment abnormalities occur. The result is thin, dry, sallow, fragile, and wrinkled skin which has poor elasticity, uneven pigmentation, and malignancies. There are many treatment options, and the cosmetic surgeon must be familiar with each of these to determine what is best suited to each patient’s needs. Botulinum neurotoxin is best suited to treat dynamic wrinkles such as crow’s-feet. A sallow complexion and hyperpigmentation often is treated successfully with topical agents such as tretinoin, bleaching agents, microdermabrasion, and light peels. Deeper pigmentation and increased vascularity can be improved with intense pulsed light. It is our belief that the best treatment of moderately deep static rhytids (such as most lower eyelid wrinkles) is laser resurfacing with the CO2 laser.
Figure 90-1 Preoperative view of a patient awaiting full-face laser resurfacing.
Figure 90-2 Postoperative appearance of the patient shown in Figure 90-1 , 6 months after full-face CO2 laser resurfacing.
Skin rejuvenation may be achieved when the top layers of aged and environmentally damaged skin are removed and replaced by healthier skin. The advantage of CO2 laser resurfacing lies in the laser’s ability to deliver extremely short pulses of high energy to a precisely controlled depth. The energy is absorbed by water in the cells, which results in cellular vaporization with minimal thermal damage to adjacent tissues.    This removes the superficial, damaged layers of skin and irritates the underlying skin just enough to stimulate new collagen development. The result is healthier, younger looking skin that has a smoother texture and more even pigmentation ( Figs. 90-1 and 90-2 ).
PREOPERATIVE EVALUATION AND PATIENT PREPARATION
The best candidates for laser skin resurfacing are patients with a fair complexion. The more pigmented the skin, the greater is the risk of development of postinflammatory hyperpigmentation. Patients who have Fitzpatrick skin types I–III ( Table 90-1 ) are at relatively low risk, while those who have Fitzpatrick skin types IV–VI are considered at high risk for hyperpigmentation. Patients who have a history of hypertrophic scar or keloid formation are at greater risk for scarring. Patients who have a history of herpes simplex virus infections are at risk for recurrent infection with scarring. Recent use of isotretinoin, recent laser resurfacing, recent chemical peeling, or radiation therapy within the past 6 months should be considered contraindications to this procedure.
Realistic patient expectations are the hallmark of success. Wrinkles and skin imperfections can be reduced, but not eliminated, with this procedure. Patients must be educated about skin care and postoperative expectations. The healing period usually is longer than implied by the lay press. Patients must understand that a significant disruption of their routine will occur for about 1 week and that they will not be able to wear cover-up makeup until epithelium has healed completely (approximately 10 days). It is essential that patients avoid sun exposure during healing, because this induces hyperpigmentation.
Skin should be treated with tretinoin and bleaching agents prior to resurfacing, which enables a more rapid re-epithelialization and reduces the risk of postoperative pigment abnormalities.
TABLE 90-1 — FITZPATRICK SKIN CLASSIFICATION SYSTEM
Always burns, never tans
Usually burns, tans less than average
Sometimes mild burn, tans about average
Rarely burns, tans more than average
Rarely burns, tans profusely
Never burns, deeply pigmented
Ideally, such treatments should begin at least 3 to 4 weeks prior to resurfacing. Hydroquinone, the most commonly used bleaching agent, inhibits tyrosinase and thereby prevents melanin production.
Successful results rely on uncomplicated healing after the procedure. Bacterial, fungal, and viral infections can occur postoperatively and may lead to scarring. Laser resurfacing can activate herpes simplex but, because many patients are unaware that they have herpes, all are treated with antibiotics and antiviral agents prophylactically.
The skin is divided into esthetic units—the periocular region, perioral region (within the nasolabial folds and the chin), forehead, nose, and cheeks. Some surgeons always treat the entire face; others treat specific esthetic units only, as determined preoperatively.
On the morning of the procedure, the patient is instructed to cleanse the skin with a mild cleanser only. The skin is prepared with antiseptic solution, which must be allowed to dry fully, because moisture on the skin interferes with the laser absorption. The patient’s head is draped in a saline-soaked cloth or crumpled aluminum foil to cover areas that are not to be treated, and metallic scleral shields are used to protect the patient’s eyes. All others in the treatment room must wear protective glasses. The procedure is performed under local anesthesia, with or without sedation. Oxygen must be turned off and the tubes removed from the field prior to treatment.
Achieving the appropriate depth of ablation can be learned only through experience, because no simple formula exists by which to determine laser settings or depth of treatment. Each brand of laser has different settings, and different settings are required for different skin types and the same skin type in different locations on the body.
Each laser pulse vaporizes a small spot of the skin, which leaves visible debris. The surgeon treats the entire esthetic unit with confluent spots. Many lasers can be used to treat a relatively large area more quickly by using a computer-generated pattern of many individual spots that are ablated on a single pass. Sterile, saline-soaked gauze or a cotton-tipped applicator is then used to wipe away the debris gently ( Fig. 90-3 ).
The skin then is examined to determine the depth of the treatment. A pink color indicates epithelial ablation ( Fig. 90-4 ), a
Figure 90-3 Periocular CO2 laser–ablated skin, with the medial aspect débrided.
Figure 90-4 Periocular CO2 laser–treated skin, with epithelium ablated.
gray color is seen in the papillary dermis, and a chamois yellow color denotes treatment to the upper reticular dermis. The skin is treated with repeated passes, as needed, but treatment should not be deeper than the upper reticular dermis. While gaining experience, it is far better to undertreat and plan on “touch-up” treatments, if necessary. If the entire face is not treated, feathering the edges by applying less total energy provides a smooth transition into untreated skin.
Laser resurfacing is very effective for the treatment of lower eyelid rhytids and crow’s-feet. The upper eyelids usually are not treated or are treated only lightly, and upper eyelid pretarsal skin is not treated. The procedure can be performed in conjunction with upper eyelid or transconjunctival lower eyelid blepharoplasty. In the treatment of lower eyelid rhytids and textural skin problems, it is important to apply laser to the lower eyelid pretarsal skin lightly to prevent ectropion. Lower eyelid laxity must be corrected prior to treatment using a lid-shortening procedure (see Chapters 88 and 89 ). Laser resurfacing should not be combined with a transcutaneous lower eyelid blepharoplasty, because the skin flap created results in decreased blood flow to the eyelid skin. This impedes skin healing and could result in scarring.
Until re-epithelialization is complete, skin must be kept moist and protected from physical stress. This can be accomplished with occlusive dressings (e.g., Flexzan), water-soluble hydrogel dressings (e.g., Vigilon, Second Skin), or topical preparations (e.g., Crisco shortening). The authors prefer occlusive dressings for the first 5 days, which are associated with more rapid wound healing and less discomfort, and which require less patient care. During this time, the dressing is changed carefully by the physician or appropriately trained staff and the skin is inspected. After 5 days, the patient is instructed to use a bland moisturizer until the epithelium has healed completely. Crusting may form and should be rinsed or soaked with warm water. It must be emphasized to the patient that to pick at the crusts can result in dermal injury and permanent scarring. As noted above, oral antibiotics and antiviral agents are used prophylactically. Discomfort is minimal and usually can be controlled well with acetaminophen (paracetamol).
After 10 days, the patient may wear makeup. Protection with sunscreen is essential. Bleaching agents are restarted prophylactically 2 weeks postoperatively to prevent excessive melanin formation. Most patients resume their normal skin care routine after 3–4 weeks. Skin health maintenance with stimulators, such as tretinoin or a-hydroxyl acids, may be resumed 1 month postoperatively.
Complications of skin laser resurfacing are uncommon when patients have been selected carefully, prepared, treated properly, and given appropriate treatment postoperatively. However, even with ideal selection and care, complications can occur. Hyperpigmentation and hypopigmentation, persistent erythema, hypertrophic scarring, lower eyelid retraction and ectropion, and infections (bacterial, viral, and fungal) all have been reported. With early detection and intervention, permanent problems usually can be prevented.
Cosmetic skin treatments are the most commonly performed cosmetic procedures. Skin care has evolved dramatically over the past few years. CO2 laser skin resurfacing remains the treatment of choice for most lower eyelid rhytids. Although technology continues to provide new avenues for skin rejuvenation, the basic principles of skin care and wound healing remain unchanged.
1. http://surgery.org/statistics.html, accessed February 25, 2003.
2. http://www.asds-net.org/index.html, accessed February 25, 2003.
3. RoTenigk HH Jr. Treatment of the aging face. In: Pinski JB, Pinski KS, eds. Cosmetic dermatology. Dermatol Clin. 1995;3(Suppl I):245–61.
4. Fitzpatrick RE, Goldman MP. Advances in carbon dioxide laser surgery. Clin Dermatol. 1995;13:35–47.
5. Green HA, Burd E, Nishioka NS, et al. Mid-dermal wound healing. Arch Dermatol. 1992;128:639–45.
6. Reid R. Physical and surgical principles governing carbon dioxide laser surgery on the skin. Dermatol Clin. 1991;9:297–316.
7. McKenzie AL. How far does thermal damage extend beneath the surface of CO2 laser incisions? Phys Med Biol. 1983;28:905–12.
8. Ho C, Nguyen Q, Lowe NJ, et al. Laser resurfacing in pigmented skin. Dermatol Surg. 1995;21:1035–7.
9. Vagotis FL, Brundage SR. Histologic study of dermabrasion and chemical peel in an animal model after pretreatment with Retin-A. Aesthetic Plast Surg. 1995;19:243–6.
10. Weinstein C. Ultrapulse carbon dioxide laser removal of periocular wrinkles in association with laser blepharoplasty. J Clin Laser Med Surg. 1994;12:205–9.