BACKGROUND: Topical antibiotics, isotretinoin or systemic antibiotics are 
usually used for acne therapy. However, isotretinoin cannot be used during 
pregnancy because it can cause significant birth defects while systemic 
antibiotics can have adverse side effects such as gastrointestinal irritation, 
photosensitivity and tetracycline sensitivity. Describe here is a 
high-intensity, narrow-band, blue light (ClearLight) system, and its therapeutic 
clinical effect is investigated on acne using cutaneous measurements, bacterial 
observations and ultrastructural changes.
MATERIALS AND METHODS: A total of 28 adult healthy volunteers with facial acne 
(mean age 28.1 years, range 16-56 years) were recruited for this study. They 
were treated with a total of eight serial biweekly 15-minute treatment sessions. 
Clinical counts of acne, as well as moisture, sebum and pH measurements were 
taken between each session. Nine of the 28 patients were followed for 2-3 months 
after the last treatment. Detection of bacteria in acne pustules was analyzed by 
culture and by polymerase chain reaction (PCR). Ultrastructural changes were 
examined in eight patients after four sessions of the light therapy.
RESULTS: All patients completed the study. Overall, there was a 64.7% 
improvement in acne lesions. There were no bacterial changes before or after the 
therapy, although damaged Propionibacterium acnes were observed at the 
ultrastructural level.
CONCLUSIONS: ClearLight performed eight times over 4 weeks can be useful in the 
treatment of acne. Further investigation will be needed to elucidate the 
mechanism of action of ClearLight.