When is surgery used for acne scarring?

Varies: Depends more if you are bothered by the scarring. Redness after acne is not scarring. Scarring on the face are depressions, and rarely elevated areas. Once the acne is under control, laser can be an effective method for improving the scars.

When it's right: Although i like many treatments for acne scarring that don't involve surgery, there are times when surgery really is the best option. Especially for the "ice pick" type of scar. These are the ones that look like "holes" in the skin. The best treatment in my hands is excision of these, followed by deep chemical peels and resurfacing of the skin. I also like prp to help with the healing.

After it's stable: Correction of acne scarring should not be undertaken, generally, until the active acne process is brought under control.