Photodynamic Therapy in the Treatment of Acne

Overview

The purpose of this research project is to study the effect of non-ablative (non-cutting) laser therapy, a technique that uses laser energy to try to improve the appearance of the skin. This type of laser treatment creates changes in a layer of the skin called the dermis without causing an open wound in the skin. The use of non-ablative laser therapy, together with application of a photo-sensitizer (substance that makes the skin more sensitive to light), may improve the appearance of acne. The idea behind the photo-sensitizer is that it is supposed to make the laser more effective than using just the laser alone. It is not yet clear how much improvement can be seen with these treatments or exactly how the skin's response causes these improvements. In this study, we are interested in learning how well such a laser works to improve the symptoms of acne, as well as how much the photo-sensitizer actually enhances the efficacy of the laser. The photo-sensitizing agent (Levulan Kerastick) and the non-ablative laser (LumaCare LC-122M non-coherent (multiple wavelengths) light source from LumaCare® Medical Products) are both FDA-approved. The Levulan Kerastick is approved for the treatment of another skin disease, not acne.

Background Acne vulgaris remains among the most common cutaneous disorders, impacting the vast majority of people at some point during their lives. It is associated with significant psychosocial morbidity, and there remains the need for efficacious and low risk therapeutic options. The FDA has approved various lasers and light sources for the treatment of acne. However, few randomized, controlled clinical trials have been performed of these devices. In addition, the use of topical photosensitizers preceding laser or light-therapy for acne has also been examined in a preliminary way with some initial evidence of efficacy. However, these trials have been small with modest numbers of subjects, many focus on back acne, and treatment protocols vary widely and are often poorly controlled. Photodynamic therapy for facial acne is being performed by physicians across the country but little objective data regarding this practice is available. We have recently conducted a trial of a 1 hour application of a common photosensitizer approved by the FDA for acne phototherapy (Levulan, DUSA pharmaceutical) using a pulsed dye laser therapy (V-Beam laser, Candela Corp., Wayland, MA, 595 nm wavelength) as the activating light source (IRB protocol 2005-0117). Interim results from our study indicate this therapy is effective in a minority of patients. Accumulating published reports data suggests the limited effectiveness of this protocol may be due to inadequate skin penetration of the photosensitizing agent and due to the need for an activating light source with a longer wavelength of light to allow deeper penetration into the skin. We wish to incorporate these findings to design a protocol that should be more effective for treatment of facial acne. Objectives We propose to evaluate the efficacy and confirm the safety of an FDA-approved non-coherent light source (LumaCare LC-122M non-coherent light source with LUM-I, fiber optic probe, 610 nm-660 nm output range, LumaCare Medical Products, Newport Beach, Ca) used in conjunction with a topical photosensitizer (Levulan, DUSA pharmaceutical) in the treatment of acne vulgaris. Because one proposed mechanism of action for such treatments includes altered sebaceous gland activity, we also seek to examine the effects of this treatment on cutaneous sebum production.