How often should I have my intraocular pressure checked? I have intraocular hypertension. Once/yr. Doesn't seem enough, after checking every 6 months.

Depends. If you have a long history of stable pressure and normal visual fields and normal corneal thickness and normal nerve fiber thickness on hrt/gdx/oct testing and you do not have diabetes and you are not african american and you are not asian then twice a year would be good depending on how high the pressure is. Three times a year will keep you on a short leash but will keep you very safe.
Glaucoma followup. Three to six months follow up is customary depending on your condition: level if iop, extent of damage, associated systemic conditions , genetics , physician preference.