Nonablative Phototherapy for Acne Vulgaris Using the KTP 532 nm Laser

Abstract

BACKGROUND. Acne vulgaris is an acute inflammatory disease of the pilosebaceous units. The bastion of treatment for acne vulgaris has been the use of topical and systemic therapies. Despite many modalities available for treatment, there exists an imperative need for effective noninvasive treatments that reduce the risks of medication side effects. OBJECTIVE. To study the safety and efficacy of the potassium titanyl phosphate (KTP) 532 nm pulsed laser for the treatment of acne vulgaris. METHODS. Twenty-six subjects, clinically evaluated with moderate facial acne, were enrolled in this single-center prospective trial. The entire facial area for each subject was divided in half and randomly designated as either a treatment or a control side. Each subject was treated with four laser exposures using a KTP 532 nm laser with continuous contact cooling. The results were assessed at 1 and 4 weeks post-final treatment. Primary outcome measures were Michaëlsson acne severity score and adverse treatment effects. Secondary outcome measures included subjective evaluations from the investigator and patients assessing their overall percent satisfaction. RESULTS. Primary outcome analysis in the Michaëlsson acne severity score demonstrated a mean 34.9% (p = .011) and 20.7% (p = .25) reduction at the 1-week and 4-week post-final treatments, respectively. Subjective investigator evaluations of overall percent satisfaction indicated that all patients demonstrated a minimum 50% overall satisfaction in treatment outcomes at the 4-week follow-up period. No side effects were encountered. CONCLUSION. Use of the KTP 532 nm laser for the treatment and management of acne vulgaris is both safe and effective, with positive results enduring up to 4 weeks post-treatment.

Selective photothermolysis to target sebaceous glands: Theoretical estimation of parameters and preliminary results using a free electron laser

“…Acne is the most common skin disease and the most common cause of permanent facial scarring 5–7. For the treatment of acne, lasers have been used with wavelengths of 1,450 nm 8, 9, 585–595 nm (PDL, pulsed dye lasers) 10–13, and 535 nm (KTP) 14. None of these wavelengths are preferentially absorbed by sebaceous glands, but may improve acne to some extent.…”

Procedural treatments for acne

“…The largest study to date showed no significant difference between treated and control sides of the face at four weeks (26).…”

Acne scarring: A review of available therapeutic lasers

“…The 532 nm potassium‐titanyl phosphate (KTP) laser emits light in the absorption range of hemoglobin. It has been used in treatment of active inflammatory acne, as its wavelength is absorbed by porphyrins produced by P. acnes , which in turn leads to oxidative damage to the bacteria .…”

“…Instead, fractional lasers create numerous, discrete columns of thermal damage with intervening untreated areas. Each treated area, known as a microscopic treatment zone (MTZ), spans an area of 100–300 μm and penetrates deeply into the tissue, up to 1,500 μm . Through the creation of these MTZs, fractional lasers induce dermal remodeling and, in the case of ablative fractional lasers, re‐epithelialization.…”