Hi ..contura Lasik aims at correcting the irregularities present on your cornea besides correcting the number. It is more required if your cornea naturally has some higher order aberrations. Your doctor can guide you acc to your case. There is approx 1in 100 chances of mild regression or some number coming back...if it so happens n it is a mild number ..don't need to do anything. If it is troubling u..a touch up is possible provided all the parameters are normal.