Options to Improve White/silver Stretch Marks?

I know i cant remove stretch marks but i want to improve them, and yes there the silvery/white ones, now some doctors say white ones cant be treated but some doctors on realself say they can, id like to know the best laser to treat these, and wether ablative or non ablative is more affective, i contacted a leading harley street clinic, and they said that the non ablative fractional star lux 1540 is the best after 4 treatments, and no prizes for guessing what treatment they offered, thankyou.