Ablative fractional lasers attempt to reduce the size of raised scars by shining an intense beam of light on the scar in a dot-matrix (imagine tiny polka dots) pattern, which completely removes (ablates) the skin in this dot-matrix pattern, leaving some of the skin intact.
Zapping away the old, damaged skin leaves a new scar behind. The newly formed scar is smaller than the old one and contains less collagen.
This treatment is normally repeated multiple times (4 times or more) in 2 to 8-week intervals. You should see gradual results with each session. After your last session, your scar(s) should continue to improve over time. However, in some cases, scars may grow back after treatment.