What is intraocular pressure and what is its norm

What is intraocular pressure

Intraocular pressure is the force with which the jelly-like liquid between the lens and the cornea presses on the membranes of the eye. This liquid is called aqueous humor. It is needed for nutrition and protection of the organs of vision. Watery moisture is partially formedEye Globe Anatomy from blood plasma, when it seeps through the small vessels of the eye. It is also secreted by the cells lining the inside of the transparent shell of the eyeball - the cornea.

Normal intraocular pressure is maintained by fluid circulation. It penetrates through the posterior chamber of the eye, which is located between the iris and the lens, and fills the anterior chamber. This cavity is located between the cornea and the iris. Then the aqueous humor goes into the bloodstream through the Schlemm canal, a circular vessel along the edge of the cornea.

What is the rate of intraocular pressure

10-20 millimeters of mercury. Moreover, this indicatorEye pressure does not depend on gender and age. If there are abnormalities, the doctor will advise treatment.

How is intraocular pressure measured?

If the pressure of the aqueous humor changes, this is a sign of pathology. Therefore, ophthalmologists measure it using tonometry.Tonometry. The study is carried out in three waysTonometry:

1. Anesthetic drops are instilled into the eye, and then paper with orange dye is applied to it. The lower the intraocular pressure, the larger the print size. To determine the area of ​​the track, a special apparatus is used - a slit lamp (with its help, you are examined at every appointment with an ophthalmologist). The chin is placed on a stand, the person directs his gaze forward and does not cover eyes, and the doctor touches the cornea with a tonometer, shines a blue light into the eye, while looking into the slit lamp and notes the pressure on the apparatus.
2. Anesthetic drops are also used. Then they touch the cornea with a small tonometer that resembles a pencil. It shows the measurement result immediately.
3. Non-contact method. A man looks into an apparatus that looks like a slit lamp. The ophthalmologist directs a beam of light onto the cornea and then a stream of air. The more it blows into the eye, the more the beam is deflected. Intraocular pressure is measured by its displacement.

How to prepare for tonometry

You don't need to do anything specialTonometry. Enough remove contact lensesso that they do not stain and affect the measurement accuracy.

If you have had eye infections or corneal ulcers, or your close family member has glaucoma, notify your doctor before the procedure. Also inform the ophthalmologist about taking medications: they can affect the tonometry result.

What to Expect During Your Procedure

Before measuring intraocular pressure, the doctor instillsTonometry pain medication to the patient. Therefore, the person does not feel pain or discomfort. If tonometry is performed in a non-contact manner, the air may tickle a little or press on the eye.

What can affect intraocular pressure

Usually, the deviation appears in case of eye diseases. But sometimes the following factors affect intraocular pressure.Intraocular pressure:

• increased central venous pressure;
• increased blood flow in the brain;
• foreign bodies in the eye;
• bleeding in the eye;
• the introduction of the drug for local anesthesia into the eye;
• decreased muscle tone of the eyeball;
• vomiting, coughing, or extreme exertion.