DAMAGE CONTROL

Treating photo-aged Asian skin can be challenging, but may be helped by non-ablative lasers such as the Piqo4, a multi-million tech available at AVIGNON CLINIC

Skin aging is a culmination of genetic and environmental factors and is largely influenced by the cumulative damage from exposure to ultraviolet (UV) radiation.

The structural integrity of the skin is formed primarily by collagen. UV radiation exposure can induce tremendous insult to the skin through various mechanisms. One understood mechanism involves the generation of reactive oxygen species (ROS). Excessive ROS are harmful to the skin because they can cause oxidative damage to cells thus contributing to collagen breakdown.

DIFFERENT KINDS

With chronological aging, exacerbated by photoaging, collagen synthesis is reduced. Increased collagen breakdown coupled with decreased neo-collagenesis results in the integrity of the dermis being compromised and the reparative response becoming defective.

The joint result of these combined mechanisms is visible skin damage evident as wrinkles. Advancing age results in natural cellular attrition and senescence that must also be acknowledged as contributors to the clinical manifestations of skin aging.

The specific histological changes in the skin caused by photoaging are distinct from those that occur due to chronological aging.

In chronologically-aged skin, collagen fiber bundles are loose, short, and thin and disorganized when compared to sun protected young skin. The epidermis is thinner, and the number of rete pegs is reduced.

In contrast, photo damaged skin is marked by elevated elastosis and collagen fragmentation beneath the dermal-epidermal junction. The epidermal thickness can be irregular, as can the morphology of epidermal cells.

CASE-TO-CASE

The exact nature of UV skin damage depends on skin type; type III and IV skin display leathery skin, lentigines and an overall “bronzed” appearance.

A yellow cobblestone appearance of the skin may also be present resulting from the elastosis in photoaging. Other manifestations include the development of benign cutaneous growths such as dermatosis papulosa nigra and seborrheic keratoses.

Additionally, changes in the dermal vasculature following UV radiation may also lead to dilatations which clinically appear as telangiectasies and if traumatized, bruising.

Researchers have reported both pigmentary changes and wrinkling to be major features of photoaging in Asians, however, moderate-to-severe wrinkling becomes apparent only at about 50 years of age, which is a decade later than in age-matched Caucasian counterparts.

MANAGING PHOTOAGING

Management of photoaging, apart from prevention of exposure to the sun, involves such therapeutic approaches as topical retinoids, 5-Fluorouracil creams, and various cosmeceuticals.

Laser skin resurfacing has become a valuable tool in the arsenal of the clinician, for assisting their patients in achieving their aesthetic goals.

The most highly-effective technique is full ablative resurfacing; however, it is associated with prolonged recovery periods and increased risk of complications including possibility of infection, dyspigmentation, and scarring.

In the Asian patient, these risks are further magnified, rendering fully ablative treatments even less desirable for routine clinical use. Fractional resurfacing has a better safety profile and is the mainstay in facial resurfacing today.

LASER TREATMENTS

Dark skin types have a few characteristics that are specifically relevant to laser aesthetic procedures: increased epidermal melanin, larger melanosomes that are more singly dispersed and widely distributed within epidermal keratinocytes, labile melanocyte responses and reactive fibroblasts.

Most importantly, dark skin types react to injury or inflammation with changes in pigment production. Thus, laser procedures are associated with a greater risk for postprocedure hyper- or hypopigmentation in individuals with skin types IV to VI.

As darker skin types have relatively large quantities of melanin in the basal layer of the epidermis, there is a higher risk for nonspecific thermal injury and untoward effects, including permanent dyspigmentation, textural changes, focal atrophy, and scarring.

The development of non-ablative and fractional lasers has broadened the scope of safe and effective treatment options for patients with darkly pigmented skin, however, this patient population requires precautions to mitigate the risk of pigmentary abnormalities.

SKIN REJUVENATION

In a recent review of the literature, post-inflammatory hyperpigmentation (PIH) was observed in up to 92 percent of ablative fractional laser-treated patients. Published studies in East Asian subjects (SPT III and IV) report favorable efficacy in the treatment of acne scarring, surgical scars and photoaging, with a considerable risk for PIH.

Fractionated laser can vary in pulse duration. Picosecond laser pulses use very high laser intensities that are provided through focused beams in short pulses.

Focusing these beams on the surface of the skin for ultrashort periods of time causes breakdown beneath the skin surface, leading to formation of voids or vacuoles. The laserinduced injury promotes wound healing processes in the dermis, either by direct stimulation or injury from the laser energy, or through an indirect mechanism such as cytokine signaling.

The injury induces neo-collagenesis and remodeling. The major advantage is the preservation of an intact epidermis with minimal disruption of the dermal-epidermal junction, which translates to shorter and milder adverse effects.

QUICK RESULTS

In the Asian population, non-ablative fractional laser may be considered a first line treatment for wrinkle reduction. The favorable side effect profile and low risk of dyspigmentation make it the preferred option for the majority of Asian patients seeking photorejuvenation as well.

One major advantage of non-ablative fractional laser is the short downtime. Erythema and edema, for example, are usually seen and resolve within two to seven days.

The Piqo4 is a non-ablative laser that provides wavelengths of 1064 nm (recommended for all skin types) and 532 nm (recommended when treating epidermal lesions in lighter skin types, I to III). The Piqo4 provides pulse duration as short as 600 picoseconds and 800 picoseconds, and the fractional handpiece allows for multiple passes, with minimal overlap.

In the country, Avignon Clinic recently purchased the Piqo4, which is also used to treat Melasma and in tattoo removals.