Rejuvenation with photodynamic therapy: clinical improvement, collagen and elastic fiber analysis

Introduction: Photodynamic therapy is a promising treatment for moderate photoaging. Objective: To evaluate the clinical and histological changes in elastin and collagen fibers following photodynamic therapy with 5-aminolevulinic acid. Methods: Female patients received three sessions of photodynamic therapy with 5-aminolevulinic acid, irradiated by a red-light (630 nm) light-emitting diode every 2 weeks.We evaluated the clinical improvement of photoaging, and also the increase in collagen and elastic dermal tissue by histomorphometry, using Picrosirius and Weigert-oxone staining, before treatment, 24 h after the first session, and 21 days after the third session.The results were evaluated using a semiquantitative method according to the following scores: 0 = absence of reaction, 0.5 = very weak reaction, 1.0 = minor reaction, 2.0 = moderate reaction, 3.0 = intense reaction. Results: Thirteen patients participated in the study.When assessed 21 days after the last treatment, 12 patients showed improvement in photoaging, especially regarding skin color and texture, clearing of solar melanosis, regression of actinic keratosis, and improvement of flaccidity. In the histomorphometric evaluation, an increase in collagen and elastic fiber tissue was observed.These outcomes have been statistically proven. Conclusions: Photodynamic therapy with 5-aminolevulinic acid, associated with red light, was clinically and histopathologically proven to be an effective treatment for clinical photoaging.

Keywords: SKIN AGING, PHOTOCHEMOTHERAPY, AMINOLEVULINIC ACID, COLLAGEN, ELASTIC TISSUE