• scar volume, scar height, scar color, scar elasticity were measured at baseline (day of laser treatment 1), Week 4 (day of laser treatment 2), Week 8 (day of laser treatment 3), Week 24 (12 weeks after the last treatment).
  

• no
  

The pulse width of the previous model of pulsed dye laser was fixed at 0.45 millisecond, whereas the pulse widths of the latest model of PDL are tunable ranging between 0.45-40 milliseconds. The long-pulsed PDL has been proven to be safe and more effective in treating certain vascular abnormalities including adult port-wine-stain and small leg vein.9-12 In the present study, we would like to investigate the effect of pulse widths on the treatment response of keloidal and hypertrophic sternotomy scars to the 595-nm PDL.

Inclusion Criteria:

• Healthy, adult subjects aged above 18.
• Subjects must be in good health as determined by the investigator.
• Presence of keloidal and hypertrophic sternotomy scars for at least 6 months
• Subjects must have no prior treatment of the scar within 1 month before the first treatment session.
• Subject or authorized representative must sign Informed Consent Form prior to study enrollment.

Exclusion Criteria:

• Female subjects known to be pregnant.
• Subjects with scleroderma, connective tissue disorders, hematologic disorders, hepatitis, infection, or uncontrolled diabetes mellitus.
• Subjects with photosensitive dermatoses such as Systemic Lupus Erythematosus (SLE)
• Subjects with a documented positive HIV test.
• Subjects who are on any types of anticoagulants.
• Subjects who are habitual smokers of cigars, pipe tobacco, or cigarettes.
• Subjects with history of radiation treatment at treatment sites.
• Subjects who use of any types of treatment of scars at the treatment site within one month before the first treatment visit.
• Subjects who are on medication that may interfere with wound healing or hemostasis.
• Subjects that have not signed the Informed Consent Form.