I've been using tobramycin andDexamethasone ophthalmic suspension .03/0.1 percent 5ml, 1 drop for both eyes 2x a day,when done w this 5ml i was told to continue but only w/ plain tobramycin 2drops both eyes every 4hrs ,but i forgot to ask d doctor on how long should i use this eyedrop and i also maintain the other eyedrop named latanoprost but was change toTimolol Maleate .5percent.by the way i was diagnosed :Primary open angle glaucoma OU,blepharitis ,posterior type OD