Acne scar is a troublesome to the patients due to its multiple depressed scar on their face and hardly covered with makeup. Various treatment modalities, alone and in combination, have been used to treat acne scars, including dermabrasion, chemical peeling, punch grafting and collagen injection. Each of these treatments have been limited by their side effects, most notably, scarring and pigmentary alteration and by unsatisfactory results. With the recent development of high energy, CO2 laser resurfacing of acne scar is effective and safe due to its exact and variable surface cutting. We describe our experiences of laser resurfacing in treating 71 patients with different severities of acne scar. From January 1996 to February 1998, We treated 71 acne scar patients with the Ultrapulse CO2 laser. Different resurfacing methods were applied according to the depth of depression and the pattern of acne scar. Pre and post laser skin care is very important to control the hyperpigmentation and to enhance the effect of laser resurfacing. Skin care program including retinoic acid, hydroquinone, hydrocortisone was applied preoperatively for at least 2 weeks, and skin care program was restarted postoperatively at 2 to 4 weeks. Patients were evaluated for pre-and posttreatment severity of acne scar. For the mild depressed scar, even resurfacing was done. For the moderate depth of acne scar, shoulder technique was combined. For the most deep and ice pick scar, laser punch out was added. Laser resurfacing was carried with 300-500mJ and 2-5 passes, and laser punch out was done with 500mJ and 3-7 continuous passes on the ice picked scar. From the pathologic finding of acne scar that was thick intradermal scar, we knew that laser punch out was necessary to improve the acne scar. Sharp demarcated margin of acne scar was faded out, and the depressed area were elevated about 60-80% with one treatment of laser resurfacing. Most of patient with acne scar were satisfied with the laser resurfacing. There was no hypertrophic scar after laser resurfacing, but erythema was lasting for 3-12 months.
  The second laser treatment was done in six patients with 10-12 month interval. It revealed to be a safe and effective method with very limited if any side effects. Laser punch out combining with even resurfacing and shoulder technique showed better result than simple even resurfacing.