When should I get the leaking seal replaced? on 1997 Lexus ES300

I was told the car has a seal that is leaking. It is no worse than when the car was checked the last time, and is not causing any problems. Was told it doesn't need to be replaced now, that the leaks are slow to get any worse and to get it checked in 1 year. Should I follow their advise or have it done soon?

Asked by for the 1997 Lexus ES300