Is it okay to use Retin-A Micro Gel 0.04% with AHA and BHA to lighten acne scars?

Thank you for your question. These products are great for exfoliation and helping with the cell turn over, which may help with any pigmentation left over time. Unfortunately any scars that are indented, ice pick or hill & valley will not significantly improve with these products. 
I recommend to use topical products that will relieve inflammation and lighten such as Kojic acid, Arbutin or Niacinamide. Depending on the skin type you could start laser treatments such as VBeam or Laser toning to help treat inflamed and pigmented scars. Retin-A micro gel will help to treat active acne lesions if any are left. When it comes to improving pigmented acne scarring it can take 2-4 months to clear depending on the treatment used. 
I hope this helps.
Regards,
Sheetal Sapra, MD, FRCPC