Ablative lasers such as the CO₂ 10,600 nm, the Erbium:YAG 2940 nm, and the Yttrium-Scandium-Gallium-Garnet (YSGG 2780 nm) ablate the target chromophore water as well as vaporize surrounding tissue. When done in a continuous wave (CW) it is called full-field resurfacing.³ The original lasers removed the entire top layer of the skin to the depth specified. CO₂ lasers are thought to have the efficacious component of not only tissue ablation but also coagulation.³ The Erbium:YAG 2940 nm is a solid-state laser that is highly absorbed in water and is used for laser resurfacing and skin rejuvenation. This frequency is much closer to the peak absorption range of water and thus has an absorption coefficient 16 times greater than the CO₂ laser (Fig. 24.1).

This greater absorption decreases the penetration depth into the epidermis by a factor of 10. This is an advantage, as more precise ablation of skin is possible with even less damage to surrounding tissue, resulting in less downtime and less complications like hypopigmentation.³ Anderson and Manstein introduced fractional photothermolysis to generate microthermal zones.⁴ This means that the energy is
delivered in columns rather than complete ablation. When this technology is utilized it creates micro-wounds in the skin surrounded by intact tissue. This heating, up to mid-reticular dermis, serves as the stimulus for inflammatory mediator release, fibroblast activation, neocollagenesis, and dermal remodeling. Furthermore, the impacted coagulation columns act like elimination channels, which expel pigment and explain the clinical lightening of lentigines and melasma. When delivered this way it allows deeper penetration into the tissue without compromising more superficial tissues.⁵ Typically, multiple treatments are required to achieve best results, but there is less downtime, an average of three days, associated with each treatment. Combinations to mimic CO₂ results for periorbital rhytids with non-ablative or ablative fractional technology are indeed efficacious.⁶,⁷,⁸,⁹ Figure 24.2 shows a patient treated very effectively for lateral canthus rhytids with the Icon platform by Cynosure. However, it takes more lasers, or a multi-platform laser, and certainly can be time consuming.¹⁰

The easiest patients to treat have fair skin (Fitzpatrick skin types I-III). Darker skin types can also be treated (Fitzpatrick skin type IV-VI)—with caution—by using lower energies, longer pulse durations, longer delay times, and aggressive skin cooling techniques.¹¹

The Fitzpatrick skin phototypes (types) were constructed based on an individual’s skin color and their tendency to burn or tan when exposed to sunlight. There are six skin types characterized by the Fitzpatrick Skin Typing Scale (Tables 24.1 and 24.2).⁹

These treatments are currently not covered by private insurance; therefore, patients must be willing to assume responsibility for the cost of treatments. Since more aggressive treatments sometimes need to be performed under general anesthesia these conversations come about while a patient has already scheduled another cosmetic surgery and built time-off into their recovery. These in-depth conversations are important to have during consultation. Fully evaluate patient needs, end result, efficacy, risks, cost, and downtime when choosing what is best for the patient.

The potential improvement is dependent on the device used and depth and degree of injury produced. There are many options and combination of options to achieve results. Practitioners use combination therapy with superficial full-field treatment combined with fractional treatment while others use fractional ablative and nonablative therapy (Fig. 24.3).¹

Still others, and the author, use intense pulsed light (IPL) with fractional nonablative resurfacing and radiofrequency.¹²,¹³,¹⁴,¹⁵ IPL addresses the superficial dyschromias and vasculature; the laser addresses texture and rhytids and radiofrequency tightens skin by building collagen through dermal heating and tissue damage.