- Elevated IOP threatens the eye's optic nerve (responsible for vision). High IOP is the main risk factor associated with glaucoma eye disease, according to AllAboutVision.com. More than 130,000 Americans are blind because of glaucoma, according to eMedicineHealth.com's report on ocular hypertension.
- Normal IOP is characterized by a balanced production and drainage of eye fluids (aqueous humor). Fluid-producing cells are functioning properly, and drainage passageways have a continuous outflow of fluids, so there is no buildup in the eye.
- Ocular hypertension is when IOP is too high because of an imbalance in eye fluids. The drainage system is blocked, and fluid builds up in the eye. This is strongly associated with the glaucoma eye disease, which can cause loss of vision.
- Eye doctors (ophthalmologists or optometrists) measure eye pressure in millimeters of mercury (mm Hg), using an instrument called a tonometer, according to eMedicineHealth.com.
- Normal IOP ranges from 10-21 mm Hg, according to SteadyHealth.com's report on eye pressure. Tonometry results that show eye pressure greater than 21 mm Hg is a sign of ocular hypertension.
- Regular eye examinations are necessary to check that eye pressure is normal, since elevated eye pressure has no signs or symptoms until the damage to the optic nerve has already been done, according to eMedicineHealth.com. Prescription eye drops are used to lower IOP.
