Clinical trial of a novel non-thermal LED array for reversal of photoaging: Clinical, histologic, and surface profilometric results

• Published in: Lasers in surgery and medicine Vol. 36; no. 2; pp. 85 - 91
• Main Authors: Weiss, Robert A., McDaniel, David H., Geronemus, Roy G., Weiss, Margaret A.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.02.2005
• Subjects: Biopsy, Needle; Double-Blind Method; Equipment Design; Equipment Safety; Female; Humans; Immunohistochemistry; laser; light emitting diodes; light therapy; Middle Aged; photorejuvenation; Phototherapy - methods; pigmentation; Prospective Studies; Sensitivity and Specificity; Severity of Illness Index; Skin Aging - pathology; Skin Diseases - pathology; Skin Diseases - therapy; skin rejuvenation; Treatment Outcome
• ISSN: 0196-8092; 1096-9101
• DOI: 10.1002/lsm.20107

Background and Objectives Photomodulation has been described as a process which modifies cell activity using light sources without thermal effect. The objective of this study was to investigate the use of a non‐thermal low dose light emitting diode (LED) array for improving the appearance of photoaged subjects. Study Design/Materials and Methods This prospective study investigated a random cohort of patients (N = 90) with a wide range of photoaged skin treated by LED photomodulation® using a full panel 590 nm non‐thermal full face LED array delivering 0.1 J/cm2 with a specific sequence of pulsing. Subjects were evaluated at 4, 8, 12, 18 weeks and 6 and 12 months after a series of 8 treatments delivered over 4 weeks. Data collected included stereotactic digital imaging, computerized optical digital profilometry, and peri‐ocular biopsy histologic evaluations for standard stains and well as collagen synthetic and degradative pathway immunofluorescent staining. Results Digital imaging data showed a reduction of signs of photoaging in 90% of subjects with smoother texture, reduction of peri‐orbital rhytids, and reduction of erythema and pigmentation. Optical profilometry showed a 10% improvement by surface topographical measurements. Histologic data showed markedly increased collagen in the papillary dermis of 100% of post‐treatment specimens (N = 10). Staining with anti‐collagen I antibodies demonstrated a 28% (range: 10%–70%) average increase in density while staining with anti‐matrixmetalloproteinase (MMP)‐1 showed an average reduction of 4% (range: 2%–40%). No side effects or pain were noted. Conclusions Photomodulation to reverse photoaging is possible with a specific array of LEDs with a specific fluence using a precise pulsing or “code” sequence. Skin textural improvement by digital imaging and surface profilometry is accompanied by increased collagen I deposition with reduced MMP‐1 (collagenase) activity in the papillary dermis. This technique is a safe and effective non‐painful non‐ablative modality for improvement of photoaging. © 2005 Wiley‐Liss, Inc.