Abstract
Objectives: To evaluate the cellular and clinical responses to facial treatment using a wide-spectrum, long-pulse infrared medical device. Methods: Thirty patients with facial skin laxity and photodamage underwent a single treatment session with the infrared device. Skin biopsies were collected before treatment and on days 5 and 21 for histological and immunohistochemical assessments of inflammatory and regenerative changes. Long-term outcomes were analyzed by biomechanical measurements (cutometry) and collagen autofluorescence quantification from histological samples. Results: Histological analysis demonstrated a 40% increase in fibroblast count, angiogenesis, and mild inflammatory activity, though these changes did not reach statistical significance. Cutometric evaluation revealed a significant improvement in skin elasticity at day 21 (+15.97%) and day 150 (+24.49%) post-treatment, accompanied by a modest increase in hydration. Collagen autofluorescence showed a statistically significant enhancement, consistent with ECM remodeling and fibroblast activation. Conclusions: A single session of treatment with a wide-spectrum, long-pulse infrared device produced measurable improvements in dermal elasticity and collagen organization with minimal inflammatory response. These findings support the efficacy and safety of infrared energy-based therapy as a noninvasive modality for facial skin rejuvenation.