As I continue to review the Medline English literature and recent international conferences regarding Fractional photothermolysis (FP) technology, applications, and indications, it becomes more obvious that this relatively new modality is one of the most significant milestones in laser technology and skin resurfacing.

Successful conditions treated with non-ablative fractional lasers reported in the literature include acne scarring; dyschromia and fine wrinkling of photoaging on the face, chest, neck, and hands; melasma; poikiloderma of Civatte; nevus of Ota; scars; minocycline hyperpigmentation; telangiectatic matting; residual hemangioma; granuloma annulare; colloid milium; and disseminated superficial actinic porokeratosis.

An advance in 2007 was the introduction of ablative FP (AFP), which results in significantly greater improvement in skin laxity and textural abnormalities. There is no doubt that AFP has demonstrated significantly greater improvement than non-ablative FP in reducing acne scarring and skin redundancy and laxity associated with photoaging.

Through the induction of microthermal zones of injury, FP technology stimulates a robust and rapid wound healing response resulting in improvement in a diversity of aesthetic, inflammatory, and preneoplastic skin disorders.

Further investigation into the technology and diverse array of cutaneous conditions that can benefit from FP will continue and bring additional data to use in determining treatment parameters and identifying new apppliations.

The concept of non-ablative fractional photothermolysis was introduced to the market in 2003 as an answer to the need for effective, yet low risk, skin resurfacing techniques. Unlike conventional ablative (CO2 and Erbium) and non-ablative lasers, fractional ablative and non-ablative photothermolysis treats only a fraction of the skin, leaving up to a maximum of 95% of the skin uninvolved. The undamaged surrounding tissue allows for a reservoir of viable tissue, permitting rapid epidermal repair.

Non-ablative fractional photothermolysis is currently approved by the US Food and Drug Administration (FDA) for the treatment of pigmented lesions, periorbital rhytides, skin resurfacing, melasma and soft tissue coagulation, acne and surgical scars, and actinic keratoses. However, its off-label use is clearly more extended. Many practitioners would agree that this first wave of fractional lasers has delivered very limited clinical efficacy.

See larger chart

In 2007 the concept was further developed, and ablative fractional photothermolysis was introduced, using an erbium yttrium aluminium garnet (Er:YAG) or carbon dioxide (CO2) laser. These devices are FDA cleared to treat wrinkles, rhytides, furrows, fine lines, textural irregularities, pigmented lesions and vascular dyschromia. (more…)

Why the newer fractional technologies are so popular?

The latest fractional laser technologies offer a better balance of efficacy, patient tolerance and lack of side effects compared to older lasers.

For better results the depth of the laser beam penetration and the depth of skin resurfacing are important. But even more important is an optimal combination of depth, microspot size, density, as well as the ratio of ablation to coagulation.

Depth is a simple term that indicates how deep the thermal damage extends into the skin tissue. It is the depth of the microcrater or hot cylinder.

Microspot size is the diameter of the microscopic wound.

Density is the percent coverage over the skin surface, e.g. 20 percent density means 20 percent of the skin surface is damaged.

The “ratio of ablation to coagulation” can be explained as follows: one pulse of laser beam produces a crater (coagulation area), which is 100 µm wide, and the lateral thermal damage (area of ablation) of 50 µm in radius (100 µm in diameter) ; therefore in this case, the total width of coagulation is 100 µm, and the total width of ablation is 100 µm, therefore 1:1. This ratio is an indication of the downtime. Coagulation is a type of thermal damage, which greatly influences wound healing.

The problem is that no one knows the precise best recipe among all of these variables to achieve the best ratio of cosmetic enhancement to days of “downtime.”