using scar strips after top surgery

my doctor was a bit vague about this. He said to start using the scar strips right away to help prevent keloids (I already have 2 keloids on my chest) I know in most cases people wait a month or so to use the strips but he said I could go ahead. But he didn't say how long to continue using them or how often?? And how long I should leave them on before changing them? Do I just leave them on 24/7?