Photodynamic Therapy Found to Reduce Rhytides

Photodynamic therapy (PDT) — a treatment most commonly thought of for field cancerization — is an effective tool for reducing rhytides and lentigines, results from a small prospective study showed.

“Our study helps capture and quantify a phenomenon that clinicians who use PDT in their practice have already noticed: Patients experience a visible improvement across several cosmetically important metrics including but not limited to fine lines, wrinkles, and skin tightness following PDT,” one of the study authors, Luke Horton, MD, a fourth-year dermatology resident at the University of California, Irvine, said in an interview following the annual meeting of the American Society for Dermatologic Surgery, where he presented the results during an oral abstract session.

For the study, 11 patients underwent a 120-minute incubation period with 17% 5-aminolevulinic acid over the face, followed by visible blue light PDT exposure for 16 minutes, to reduce rhytides. The researchers used a Vectra imaging system to capture three-dimensional images of the patients before the procedure and during the follow-up. Three dermatologists analyzed the pre-procedure and post-procedure images and used a validated five-point Merz wrinkle severity scale to grade various regions of the face including the forehead, glabella, lateral canthal rhytides, melolabial folds, nasolabial folds, and perioral rhytides.

They also used a five-point solar lentigines scale to evaluate the change in degree of pigmentation and quantity of age spots as well as the change in rhytid severity before and after PDT and the change in the seven-point Global Aesthetic Improvement Scale (GAIS) to gauge overall improvement of fine lines and wrinkles.

After a mean follow-up of 4.25 months, rhytid severity among the 11 patients was reduced by an average of 0.65 points on the Merz scale, with an SD of 0.20. Broken down by region, rhytid severity scores decreased by 0.2 points (SD, 0.42) for the forehead, 0.7 points (SD, 0.48) for the glabella and lateral canthal rhytides, 0.88 points (SD, 0.35) for the melolabial folds and perioral rhytides, and 0.8 points (SD, 0.42) for the nasolabial folds. (The researchers excluded ratings for the melolabial folds and perioral rhytides in two patients with beards.)

In other findings, solar lentigines grading showed an average reduction of 1 point (SD, 0.45), while the GAIS score improved by 1 or more for every patient, with an average of score of 1.45 (SD, 0.52), showing that some degree of improvement in facial rhytides was noted for all patients following PDT.

“The degree of improvement as measured by our independent physician graders was impressive and not far off from those reported with CO2 ablative laser,” Horton said. “Further, the effect was not isolated to actinic keratoses but extended to improved appearance of fine lines, some deep lines, and lentigines. Although we are not implying that PDT is superior to and should replace lasers or other energy-based devices, it does provide a real, measurable cosmetic benefit.”

Clinicians, he added, can use these findings “to counsel their patients when discussing field cancerization treatment options, especially for patients who may be hesitant to undergo PDT as it can be a painful therapy with a considerable downtime for some.”

Lawrence J. Green, MD, clinical professor of dermatology, The George Washington University, Washington, DC, who was asked to comment on the study results, said that the findings “shine more light on the long-standing off-label use of PDT for lessening signs of photoaging. Like studies done before it, I think this adds an additional benefit to discuss for those who are considering PDT treatment for their actinic keratoses.”

Horton acknowledged certain limitations of the study including its small sample size and the fact that physician graders were not blinded to which images were pre- and post-treatment, “which could introduce an element of bias in the data,” he said. “But this being an unfunded project born out of clinical observation, we hope to later expand its size. Furthermore, we invite other physicians to join us to better study these effects and to design protocols that minimize adverse effects and maximize clinical outcomes.”

His co-authors were Milan Hirpara; Sarah Choe; Joel Cohen, MD; and Natasha A. Mesinkovska, MD, PhD.

No relevant disclosures were reported. Green had no relevant disclosures.