Intraocular pressure (IOP) is a measure of the pressure created by the balance of fluid production and drainage in the eye. When eye pressure becomes too high or too low, potentially serious vision problems can result. There are usually no overt symptoms of high IOP (called ocular hypertension), so you may not know your levels are elevated until glaucoma or optic nerve damage are present. If you are experiencing any of the symptoms below, contact your eye doctor as soon as possible.
Elevated Eye Pressure Symptoms
According to All About Vision, between 4.5 and 9.4 percent of adults over the age of 40 are estimated to have elevated IOP, or ocular hypertension. While not everyone with elevated levels of intraocular pressure (IOP) will develop glaucoma or incur damage to the optic nerve, some may begin to see signs of visual impairment over time. African-Americans, those with a genetic history of glaucoma, and those with health conditions like diabetes are at higher risk of developing glaucoma if they have ocular hypertension. Primary open-angle glaucoma is the most common type of glaucoma, and it may initially cause symptoms of peripheral or side vision loss. It can advance to central vision loss or tunnel vision in one or both eyes, eventually leading to blindness if it is left untreated.
Emergency Symptoms
Sometimes rapid increases of eye pressure can cause the sudden onset of a condition called acute angle closure glaucoma. Without warning, symptoms of severe visual impairment can appear, and permanent vision loss can occur rapidly. If you experience symptoms such as nausea and vomiting, severe eye pain, seeing colored rings around lights, blurred vision and redness in the eye, you should seek medical attention right away to try to minimize damage to your vision.
Ocular Hypotony
Ocular hypotony, or intraocular pressure that is too low, can sometimes occur in response to eye trauma or surgery, or poor blood flow to the eye. Generally, IOP below 6 millimeters of mercury is considered hypotonic (normal IOP typically falls between 12 and 22 millimeters of mercury). Hypotony distorts the retina and cornea, causing cataracts and edema (swelling). Symptoms may include decreased, blurred or distorted vision, or fluctuating clarity of vision. Vision changes can be slight, acute or severe depending upon how severely the retina and cornea are affected. Eyes with low IOP may also often be inflamed and painful.
