Skin responses to fractional photothermolysis

Fractional resurfacing

Fractional resurfacing produces a distinctive thermal damage pattern by creating discrete columns of thermal damage referred to as microthermal treatment zones. It characteristically spares the tissue surrounding each microthermal treatment zone leading to fast epidermal repair. Fractional resurfacing has been successfully used in treating a variety of skin conditions including melasma, dyschromia, lentigenes, wrinkles, and acne scars with minimal downtime. It is safer to use off the face and in darker skin types.

Fractional Photothermolysis: A Novel Aesthetic Laser Surgery Modality

The ubiquity of increased sun exposure, oral contraceptives, and phototoxic drugs has led to an increased prevalence of conditions such as dyschromia, melasma, rhytides, and other signs of photoaging over the past few decades. Through the application of selective photothermolysis, laser surgery has attempted to create therapeutic options for these medically recalcitrant conditions. To date, however, this technology has been met with limited success, due to a high incidence of posttreatment side effects, inability to treat off the face, and a safety profile tailored to Fitzpatrick skin types I to III. More recently, a novel approach coined "fractional photothermolysis" was developed in an attempt to overcome these limitations. This new laser treatment modality has allowed for effective treatment of a diverse array of dermatologic conditions on and off the face with a wider therapeutic index and improved safety profile independent of Fitzpatrick skin type. This review sheds light on the technical aspects, biologic mechanisms, and clinical effects of fractional photothermolysis that help set it apart from previous modes of laser surgery.

Fractional Resurfacing for the Treatment of Hypopigmented Scars: A Pilot Study

BACKGROUND

Treatments for hypopigmented scars have shown limited efficacy and variable safety profiles. OBJECTIVE This study evaluated the safety and efficacy of fractional resurfacing (1,550-nm Fraxel SR laser, Reliant Technologies, Mountain View, CA) for the treatment of hypopigmented scars on the face in seven patients.

MATERIALS AND METHODS

Seven patients with hypopigmented scars on the face received between two and four successive treatments at 4-week intervals with the 1,550-nm Fraxel SR laser. Energy settings ranged from 7 to 20 mJ and a total density of 1,000 to 2,500 microthermal zones per square centimeter. Digital photographs were taken before each treatment and at 4 weeks after the last treatment. Independent physician clinical assessments were performed.

RESULTS

Independent physician clinical assessment 4 weeks after the final Fraxel SR laser treatment revealed improvements of 51% to 75% in hypopigmentation in six of seven patients. One patient had only 26% to 50% improvement in hypopigmentation. Additionally, clinical improvements were noted in the overall texture of the treated skin. The patient's degree of satisfaction paralleled the physician's assessment of improvement. All patients reported improvement in hypopigmentation lasting greater than 3 months after the last treatment. Side effects were limited to mild pain during the treatment and mild posttreatment erythema and edema, which resolved in 2 to 4 days.

CONCLUSION

Fractional resurfacing is a potentially effective modality for the treatment of hypopigmented scarring on the face. No adverse effects were observed.

The Use of Fractional Laser Photothermolysis for the Treatment of Atrophic Scars

BACKGROUND

Patients with atrophic scars commonly seek treatment for their removal but are often concerned about the prolonged recovery, short-lived results, and/or ineffectiveness of available therapies. A novel treatment using a 1,550-nm erbium-doped fiber laser to induce fractional photothermolysis of treated skin has been used to resurface photodamaged skin but has not been studied previously in patients with atrophic scars to determine its effectiveness for this condition.

PURPOSE

To determine the effectiveness and safety of 1,550-nm erbium-doped fiber laser treatment on atrophic scars.

METHODS

Fifty-three patients (skin phototypes I-V) with mild to moderate atrophic facial acne scars received monthly treatment with a 1,550-nm erbium-doped fiber laser (Fraxel, Reliant Technologies Inc., San Diego, CA). Clinical response to treatment was determined at each treatment visit and 6 months after the final treatment session by two independent assessors using a quartile grading scale. Side effects and patient satisfaction were monitored at each follow-up visit.

RESULTS

Clinical improvement averaged 51% to 75% in nearly 90% of patients after three monthly laser treatments. Mean improvement scores increased proportionately with each successive laser session. Clinical response rates were independent of age, gender, or skin phototype. Side effects included transient erythema and edema in most patients, but no dyspigmentation, ulceration, or scarring.

CONCLUSIONS

Atrophic scars can be effectively and safely reduced with 1,550-nm erbium-doped fiber laser treatment.

Fraxel Skin Resurfacing

Fractional photothermolysis is a new skin resurfacing laser technology for treating wrinkles, melanocytic pigmentation, scars, and photodamaged skin. Treatment with the Fraxel laser (Reliant Technologies, Inc.) creates microzones of injury in the skin that are surrounded by normal intervening skin that rapidly heals the injured tissue. From June to November of 2005, 70 patients underwent 2 to 6 treatments with the Fraxel laser (Reliant Technologies, Inc.) on the face and/or extremities for abnormal pigmentation, wrinkles, and scars. Treatments were 1 to 3 weeks apart. Clinically, the patient experienced little downtime other than erythema and edema for a few days followed by light skin exfoliation for a few days. After treatment, skin color and texture were more homogeneous with a decrease in the unwanted melanocytic pigmentation. The skin showed a decrease in rhytids. In summary, fractional photothermolysis improved skin color and texture and decreased fine wrinkles and melanocytic pigmentation with minimal downtime for the patient.

Fraktionierte Photothermolyse

Fractional photothermolysis (FP) has been recently introduced as a new concept in dermatologic laser medicine. FP employs an array of small laser beams to create many microscopic areas of thermal necrosis within the skin called microscopic treatment zones (MTZ). Even though FP completely destroys the epidermis and dermis within these MTZ, the 3-dimensional pattern of damage heals quickly and with few side effects. FP is currently used to treat fine wrinkles, photodamaged skin, acne scars, and melasma. Due to its clinical efficacy and limited side effects FP has established itself in the past two years as an alternative treatment modality to the conventional ablative and non ablative laser therapy.