Definition of Intraocular Pressure

Intraocular pressure (abbreviated as IOP) is the measurement of the amount of fluid inside the eyes. This fluid is called aqueous humor and provides nourishment to the cornea, iris and lens and allows the eyes to maintain their spherical shape.

Tonometry

• Tonometry is the method used to measure intraocular pressure. This is a test performed by an optometrist or other medical professional. There are a number of such tests. The applanation method analyzes the amount of pressure required to flatten a small area of the cornea. By measuring the pressure needed to flatten that section, the doctor or technician can determine the amount of force exerted by the fluid behind the cornea and within the eye. Another tonometric method is non contact, popularly known as the air-puff. Here, intraocular pressure is determined by a puff of air blown into the eye. The doctor also shines a light into the eye and measures intraocular pressure by the changes in the light's reflection when air is blown into it. To prevent any discomfort or pain, numbing eye drops are administered for both methods.

Glaucoma

• Intraocular pressure is measured primarily as a preventative test for glaucoma, a condition that is one of the leading causes of blindness in the United States. There are two types of glaucoma: acute and chronic. Acute glaucoma occurs when aqueous fluid is blocked from draining from the eye, causing a severe spike in intraocular pressure, which causes extreme pain and can cause blindness. Chronic glaucoma occurs over a period of time and is painless but slowly damages the optic nerve and causes blurred vision, which eventually results in blindness.

Prevention/Solution

• Regular eye exams are essential for glaucoma prevention. Because chronic glaucoma has few noticeable symptoms before causing vision damage, regular eye exams, in which intraocular pressure is checked, are necessary to maintain eye health. If intraocular pressure is high, prescription eye drops have been shown to reduce pressure, which reduces the risks of developing glaucoma. Other ways to prevent the development of glaucoma include maintaining a healthy weight and monitoring blood pressure.

Medical Treatments

• In addition to a prescription eye drops, other treatments for high intraocular pressure and chronic glaucoma include surgical interventions that reduce intraocular pressure and repair damage to the optic nerve, as well as oral medications that decrease the pressure of the aqueous humor in the eye.

Lifestyle Treatments

• Lifestyle changes can reduce the symptoms of glaucoma, such as drinking small amounts of water throughout the day. Large amounts of water (more than a quart within a brief period) can momentarily increase intraocular pressure. Also, exercise can lower blood pressure as well as intraocular pressure, but exercises should be analyzed by a medical professional as some exercises (namely those with face-down positions) can increase intraocular pressure.