This study evaluates a new combined technique using two different laser wavelengths and Platelets Rich Plasma (PRP) to treat post-atrophic acne scars. Within the available knowledge of laser-tissue interactions and effects of PRP on wound healing, we will explore the clinical effects of our new combination procedure on a histopathological and immunohistochemical basis for guiding future post acne scars clinical research.

The carbon dioxide and erbium lasers have been the gold and silver standards for acne scars treatment. As with selective photothermolysis, a major advance in the field is the incorporation of grids of MicroThermal Zones (MTZ) that spares islands of skin with an attractive treatment efficacy to downtime healing (5-7 days) ratio. Application of these fractionated resurfacing to carbon dioxide and erbium lasers allows deeper penetration into the skin.

Fractional photothermolysis was first described by as a new method for delivery of laser energy with the potential of laser safety and efficacy. Through the delivery of microscopic, non-contagious zones of thermal damage using a 1550 nm, mid-infra-red laser source, it was observed that surrounding islands of dermal and epidermal cells facilitated post-treatment collagen remodeling and rapid healing. Despite the success of minimally ablative and fractional technologies, there remained a need for more aggressive tissue ablation for the purposes of tissue rejuvenation of severely photodamaged skin and deeper rhytides. This might be due to the variability of architecture, depth, and width; thus, each type of scar has an optimal method by which it can be improved.

The idea of combining both carbon dioxide and erbium lasers appeared even before the era of fractional lasers. McDaniel et al, combined both non-fractional lasers for resurfacing of perioral rhytides comparing it to using carbon dioxide lasers alone and concluded that carbon dioxide laser resurfacing followed by 3 passes of erbium laser reduces the duration of crusting, swelling and itching when compared to carbon dioxide laser resurfacing alone with no significant difference in the outcome.

Later in 2010, the combination of fractional lasers carbon dioxide and erbium-doped laser was tried out for treating mild acne scars by a group of researchers. They reported a longer post laser erythema and hyperpigmentation, without precise pathogenesis. However, they suggested that these unexpected outcomes may have resulted from bulk heat damage to the surrounding tissues by heat stacking and recommended further studies to determine the optimal treatment parameters and reduce unexpected adverse reactions.

Platelet-rich plasma (PRP) is a high concentration of platelets in a small volume of plasma. PRP contains various growth factors and cytokines released by platelets, and those substances play a critical role in all aspects of the wound healing process. Among the stored mitogenic factors essential for wound repair are platelet-derived growth factor (PDGF) with the -AB and -C isoforms predominating, transforming growth factor β (TGF-β), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), platelet-derived epidermal growth factor (PDEGF) and insulin-like growth factor-1 (IGF-1). These are variously involved in stimulating chemotaxis, cell proliferation, and maturation. PDGF is a powerful chemoattractant and stimulator of cell proliferation. All of them are potent angiogenic factors and endothelial cell mitogens. The wound healing effect of PRP is relatively well known, and PRP has been used in bone surgery, tendon and ligament repair, and chronic leg ulcer treatment.

Inclusion Criteria:

1. Patients with atrophic post-acne scars.
2. Patients without surgical &/or LASER resurfacing treatment for acne scars within the last 6 months.

Exclusion Criteria:

1. Pregnancy
2. Present or past history of hypertrophic scars or keloids
3. Present or past history of photosensitivity dermatoses including Connective Tissue Diseases.
4. Present history of herpes infection
5. Present history of Anemia (HGB < 10 g/dl), Thrombocytopenia &/or Platelets dysfunction.
6. Patients receiving isotretinoin within the last 3 months, NSAIDs within 72 hours of the procedure, anticoagulants &/or systemic use of corticosteroids within 2 weeks.