There are generally two types of doctors you can seek out in Singapore for subcision.
The first group are dermatologists.
The second group are aesthetic doctors. Amongst this group, some are more focused on facelifts/threadlifts, and some also have a special interest in the treatment of acne and acne scars.
These suggestions are naturally not exhaustive, as there are many other doctors who are really experienced with subcision. I’ll update this answer if I learn of any more doctors who have a special interest in treating acne scars.
You may also want to refer to this post on guide to acne scar treatments.
Subcision is a good treatment for ice pick type acne scars, but as the guide explains, it’s best to have your doctor assess your skin type and scar first. He or she can then recommend you on the best treatment modality.