Contactless tonometry: preparation, examination and results
Eating the eye and maintaining its shape provides normal eye pressure. In the event of various diseases or as a result of overwork, eye pressure may change. In this case, a person experiences discomfort, he is suffering from headaches. To detect violations in time, you should regularly do tonometry. In this case, you can see deviations in time, prescribe treatment and prevent the occurrence of irreversible violations of the function of the most important sense organ - the eyes.
What is tonometry?
Tonometry is a test that makes it possible to measure intraocular pressure( IOP).This test is done to check for eye diseases, for example, glaucoma, which occurs due to damage to the optic nerve and can cause blindness. The optic nerve can be damaged due to the accumulation of fluid that circulates incorrectly.
To measure intraocular pressure, a tonometer is used that shows the resistance of the cornea to pressure.
Methods of tonometry
At the moment, the measurement of intraocular pressure is one of the three most common methods:
- contactless tonometry;
- finger tonometry;
- tonometry according to Maklakov.
Some methods of tonometry are quite simple, while others, in turn, require the use of expensive equipment.
Eye tonometry according to Maklakov is considered to be a more accurate method of measuring eye pressure. But often you have to use other methods. For example, with a large flow of patients or in cases where direct contact with the eye is prohibited according to indications, contactless tonometry of the eye is performed.
This method is based on the reaction of the cornea of the eye. It is pressurized with air. Contactless tonometry is performed only by specialists - optometrist or ophthalmologist. Because this method is painless, there is no need to use drops for local anesthesia during the procedure.
Non-contact eye tonometry is a quick and simple process of measuring eye pressure. First the patient puts his chin on a special stand and looks into the slit lamp. The doctor sits in front of him and shines with bright light. He, using special equipment, causes a slight air impact to the patient's eye. In this case, the tonometer records measurements of eye pressure associated with exposure to light on the cornea of the eye, which changes its shape during this procedure. The duration of the procedure is only a few seconds.
If necessary, the doctor can repeat this procedure several times for each eye.
Contactless tonometry is often used to check intraocular pressure in children and operated patients using the LASIK technique. It should be recalled that this method has no complications and is easily tolerated by patients.
Why do I need tonometry?
Non-contact tonometry is not used to detect glaucoma, but only to monitor the effectiveness of its treatment. That is, such a regular procedure gives specific information about whether the intraocular pressure corresponds to the threshold set by the doctor, or not.
During regular examination, the ophthalmologist also checks for intraocular pressure. This makes it possible, on detection of increased indicators, to prescribe treatment in time and prevent glaucoma.
How to prepare for tonometry
Before the procedure, you need to remove contact lenses. It should be remembered that you can wear contact lenses only 2 hours after tonometry. It is recommended to take your glasses with you.
Doctors need to be informed about whether the relatives had glaucoma. Also it is necessary to find out from the doctor what are the risk factors that contribute to the development of this disease, and report on the presence of such ones.
Before the procedure, it is better to relax, remove tight clothing from the neck. In order for the tonometry data to be as accurate as possible, it is necessary:
- Do not drink more than 0.5 liters of fluid 4 hours before the procedure.
- Do not drink alcohol during the last 12 hours.
- Do not smoke marijuana during the day before testing.
The accuracy of results can also be influenced by such factors:
- Eye surgery in the past or laser vision correction.
- The cornea is irregular in shape.
- Blinking during testing.
- Pain in the eye or eye infection.
Results of tonometry
Each person has normal ocular pressure different. Usually it gets higher right after the person wakes up. Frequent changes in intraocular pressure are characteristic of people who have glaucoma.
Specialists have noticed that female representatives have slightly higher eye pressure than men. But practically in all people it increases with age.
Intraocular pressure is considered normal if the tonometry values are within 10-21 hectograms-millimeters. If it rises above 21 millimeters per hectogram, you should immediately call your doctor. Such people are at risk, because these indicators can indicate the development of glaucoma.
Tests using different tonometers can be done several times a year, during regular examinations with a specialist. If the tonometry of the eye showed high blood pressure, you should not worry prematurely. It is better to conduct several more tests using other methods of examining the state of the eye.