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Impact of skin hydration on patterns of microthermal injury produced by fractional CO2 laser

Preclinical study examines how variations in skin hydration impact laser penetration depth, a crucial factor for the effectiveness and safety of laser treatments.

By Andrea Alstad | Dec 22, 2023

Ablative fractional lasers (AFLs) are cornerstone modalities in the treatment of scars, rhytids, and photoaging. They are increasingly used in emerging technologies such as laser-assisted drug delivery. During AFL procedures, precise and predictable laser-tissue interactions are crucial. A recent preclinical study assessed differences in skin hydration and their effect on lasers’ penetration depth. 

The study, led by Emily Wenande MD, PhD, is titled “Impact of skin hydration on patterns of microthermal injury produced by fractional CO2 laser.”  The study, published in Lasers in Surgery and Medicine (LSM), the official journal of the American Society for Laser Medicine and Surgery, Inc. (ASLMS), was selected as the December 2023 Editor’s Choice.


“During my PhD years, a question that kept my curiosity chronically piqued was how much skin hydration affected my results,” Wenande said. “Working on laser-assisted drug delivery with water-targeting lasers, I was all too familiar with the phenomenon that identical laser settings didn't guarantee identical laser channel dimensions. 

How much was skin hydration to blame? The question seemed so fundamental that it bordered on the banal. Discovering how few studies were available on the topic left me surprised - and determined to change that.”

The study investigated the impact of skin hydration on microchannel dimensions produced by a fractional CO2 laser, determined by histological analysis and optical coherence tomography (OCT) imaging. Both hyperhydration and dehydration reduced depths of laser ablation and thermal impact compared to normohydrated control skin. The thermal effects of fractional CO2 laser are relatively reproducible regardless of skin hydration under otherwise standard conditions. Still, in clinical contexts where skin hydration deviates significantly from healthy skin i.e., scars or dry, hyperkeratotic lesions, laser therapy might be more meaningfully affected. 

Emily Wenande, MD, PhD, is a Danish-American post-doctoral researcher and physician-scientist in Professor Merete Haedersdal's lab at the Department of Dermatology, Bispebjerg Hospital in Copenhagen, Denmark. She is a former research fellow of the Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, USA. An alumna of Copenhagen University, Dr. Wenande completed her PhD on laser-assisted drug delivery (LADD) in 2019. She continues her work on LADD and other experimental treatment approaches for keratinocyte carcinoma at Bispebjerg Hospital—the birthplace of daylight photodynamic therapy. Dr. Wenande hopes to develop simple, efficacious, and tolerable treatments for premalignant and malignant skin lesions through her preclinical and clinical work.

Editor’s Choice is an exclusive article published in LSM, the official journal of ASLMS. View the complete manuscript.

The American Society for Laser Medicine and Surgery, Inc. (ASLMS) is the largest multidisciplinary professional organization dedicated to the development and application of lasers and related technology for health care applications. ASLMS promotes excellence in patient care by advancing biomedical application of lasers and other related technologies worldwide. ASLMS membership includes physicians, surgeons, nurses, and allied health professionals representing multiple specialties, physicists involved in product development, biomedical engineers, biologists, industry representatives and manufacturers.  


The American Society for Laser Medicine and Surgery, Inc. is the world’s largest scientific organization dedicated to promoting research, education and high standards of clinical care in the field of medical laser applications. It provides a forum for the exchange of scientific information and participation in communicating the latest developments in laser medicine and surgery to clinicians, research investigators, government and regulatory agencies, and the public.

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