My Son Is 17 He Has Had Tubes In Both

my son is 17 he has had tubes in both ears since he was 8 they don't come out. We think he has something going on with his sinus because the ear is drawing clear fluids, their is no fever just felling like a clogged ear we have him on amox and Otc sinus meds. We don't wanna put drops into the ear due to the tubes. This is say number five what do u think we should do?