DENVER – An investigational 1726-nm without histologic disruption to the surrounding dermis, results from a small study showed.
Dr. Emil A. Tanghetti
“It is our belief that if we can destruct the sebaceous glands, it will cure acne,” Emil A. Tanghetti, MD, said at the annual conference of the American Society for Laser Medicine and Surgery. “High-dose red light PDT [photodynamic therapy] has been used, but it causes epidermal damage and an unacceptably long recovery time. Gold and silver nanoshells with infrared light have also been used. Usually these particles do not get into the sebaceous glands and appear to result in temporary improvement by wounding the infrainfundibular region of the sebaceous gland complex. It’s been shown that the 1726-nm light can target sebum and might be able to selectively damage sebaceous glands.”
Dr. Tanghetti, of the Sacramento-based Center for Dermatology and Laser Surgery, along with R. Rox Anderson, MD, and Fernanda H. Sakamoto, MD, PhD, of the Wellman Center for Photomedicine at Massachusetts General Hospital, Boston, are studying a 1726-nm laser being developed by Accure. This device uses robust and precise air cooling, a creative pulsing strategy to enhance the differential sebum to water absorption, and active, real-time monitoring via thermal imaging.
“The device is constructed to turn off before an unsafe temperature is reached,” Dr. Tanghetti said. “The thermal camera is looking at the treatment site as it happening. If it gets too hot, it can turn the whole device off. You can only do real-time monitoring with air cooling. You cannot do it with contract cooling or cryogen cooling.”
In a study of 10 patients with acne, the researchers developed a multiple pulse strategy to slowly and preferentially heat sebaceous glands while sparing the epidermis and the surrounding dermis. They performed 3.5-mm punch biopsies at 24, 48, and 72 hours after treatment, and evaluated them with hematoxylin and eosin staining.
From a clinical standpoint, Dr. Tanghetti and his colleagues noted small papules in the treated areas immediately, 24 hours and 72 hours after treatment. “You don’t see the epidermal damage that you would see with someone who had PDT,” he said.
Histologic evaluation of tissue specimens at 24 and 72 hours revealed destruction of sebaceous glands in the dermis characterized by loss of the definition of the sebocytes, and eosinophilic changes of the basal cell layer of these glands. The collagen surrounding the gland appeared to be preserved, with occasional small clots observed in the adjacent blood vessels. “There was no obvious damage to the surrounding dermis or other follicular structures,” Dr. Tanghetti said. “The hard thing is to differentiate complete damage [of the sebaceous gland] from partial damage. That’s something we’re working on by looking at sebum production, which is going to be the ultimate outcome.”
The study authors reported having numerous financial ties to medical device and pharmaceutical companies.