Lasers, even under the best of circumstances, carry with them the potential for causing unwanted pigmentary alterations, including permanent loss of pigmentation. With an obvious tendency to vitiligo, the level of concern is legitimately raised that much more. So, I would be inclined to agree with your dermatologist. However, there are a number of simple and quite effective acne scar treatments that carry little if any risk of engendering unwanted pigmentary consequences, including loss of pigmentation. These include field subcision to elevate acne scar sunken cheeks and temples; and individual subcisions to elevate and smooth depressed rolling and boxcar scars. If carefully performed, in experienced hands, ice pick scars can be treated by TCA CROSS, so long as the treating physician is careful to instill the acid deep within the pit and avoids surface application. Professional medical microneedling, too, is unlikely to give rise to loss of pigment; it is used, in fact, along with certain topically applied pigment enhancing prescription items to treat individual sites of vitiligo. Make sure that you are consulting with a board certified dermatologist experienced in all forms of acne scar treatments. Best of luck to you.