Acne scars are tough to treat.
Superficial acne scars may be helped by chemical peels, doing what we call "skin resurfacing." This will not work for the deeper etched lines. Most lasers are not safe to do on the body.
If you have a few deeper pits, you can fill them with soft tissue fillers like Juvederm or Restylane. Usually this is too pricey and not worth it for an area like the back or buttock. This fillers generally last for around 6 months.
In the past acne pits were filled with liquid silicone. This is NOT good--usually the silicone encapsulated, turned hard, and then the body eventually spit it out.
Fat grafting to individual areas has been found useful. There is some evidence the fat actually helps improve the quality of the overlying scarred skin.
The skin on the back is thicker than the rest of the body. When looking at your scars, if they look deeper and etched, any treatment which goes that deep can have a bad effect like scarring or depigmentation. If your skin is darker, be careful. Some treatments can change the color of your skin.
Find an honest doctor. I find this an area where people can spend thousands of dollars on treatments which won't work. I see doctors advertising in our local Bay Area papers using misleading advertising. Look critically at any photos: Some physicians use tricks with exposure and flash to make the results look better than they are, or only show photos at a couple weeks out, where the swelling from a laser may make the scars look better than they will look a few weeks later when the swelling subsides.
