Eye tonometry - techniques for measuring eye pressure. Daily tonometry Daily tonometry

Daily eye tonometry is the most important medical procedure for the early detection of glaucoma. It can be performed with a Goldmann applanation tonometer, Maklakov tonometer or various non-contact tonometers. Daily tonometry is a systematic measurement of intraocular pressure over 7-10 days, or 3-4 days in a shortened course.

The rhythms of pressure fluctuations inside the eyeball during the day can be:

• direct - when ophthalmotonus indicators are maximum in the morning and minimum in the evening;
• reverse - when intraocular pressure is reduced in the morning and increased in the evening;
• daytime - a very rare case when the values ​​of ophthalmotonus are maximum during the daytime;
• incorrect - when pressure measurements inside the eyeball can be presented during the day in the form of a two-humped curve.

Detecting glaucoma using 24-hour tonometry

Intraocular pressure is usually measured 3 times a day: from 6 to 8 am, in the middle of the day and from 6 to 8 pm. Daily tonometry of the eye is carried out in a glaucoma clinic or hospital. During the study, the average morning and evening values ​​of the eye pressure level and the amplitude of fluctuations between these values ​​are calculated. The normal range of such fluctuations should not be higher than 5 mm Hg. Otherwise, the presence of glaucoma is assumed.

During daily tonometry, rises in intraocular pressure above 26 mm Hg are of great importance. If they are detected repeatedly, we can speak with a high degree of certainty about the development of glaucoma in the patient.

It is considered one of the most important indicators of the condition of our visual organs. With the modern pace of life, the risk of various eye diseases only increases. Therefore, measuring ophthalmotonus becomes a necessary procedure that allows a person to maintain clarity and visual acuity for as long as possible.

In addition, to determine some eye pathologies, measurements are required several times a day. What is daily tonometry? For what diseases is it prescribed? What are the features of this method? You will find answers to these questions in this article.

Daily tonometry - measuring IOP at least 3 times a day

Daily tonometry is a procedure for systematically measuring intraocular pressure (IOP) at least three times a day for several days.

As a rule, the examination lasts from seven to ten days, since in most cases, disorders of ophthalmotonus do not appear immediately. But it can be carried out in a shortened course for 3-4 days.

The minimum number of IOP measurements during the examination period should be 6. In this case, 3 measurements should be made in the morning and 3 in the evening.

Daily tonometry can be performed both in the hospital and on an outpatient basis. But it is preferable to conduct the examination in a hospital setting. Then the data obtained will be the most accurate and informative.

Indications for use

Daily tonometry is a necessary medical examination aimed at identifying a person at an early stage of the development of the disease.

Glaucoma is an eye disease that causes problems, gradually leading to deterioration or complete loss of vision. This disease can occur in a person at any age. However, doctors cannot definitely name the reasons for the development of glaucoma.

As a rule, in the early stages the disease is practically asymptomatic. Therefore, a regular examination does not give anything. The disease may be indicated by increased intraocular pressure. In such cases, the doctor prescribes daily tonometry.

Daily tonometry allows the ophthalmologist to timely and more accurately assess the extent of the disease, choose a treatment regimen, predict possible risks and consequences, as well as monitor and adjust the treatment process.

Methodology for daily tonometry

To detect glaucoma, measurements are taken at least 3 times a day for 7-10 days. The first measurements are taken early in the morning between 6 and 8 o'clock while the patient is in bed. Iphthalmotonus is then measured in the middle of the day.

The third measurement is made in the evening from 18.00 to 20.00. It is very important to take measurements at the same time. The procedure is usually carried out daily, but a break of several days is also possible. In some situations, intraocular pressure is measured every 2 hours. In this case, the examination is carried out only in stationary conditions.

If 24-hour tonometry is used to monitor the effectiveness of treatment for a patient diagnosed with glaucoma, then certain conditions must be met. Namely:

1. carry out IOP measurements in the morning and evening hours at the same time;
2. Before tonometry, do not instill antihypertensive medications in order to determine the pressure at the end of the drug's effect.

Thus, daily tonometry allows you to establish:

• level of ophthalmotonus in the right and left eyes;
• daily fluctuations in IOP;
• reaction of intraocular pressure to the selected treatment regimen.

To measure intraocular pressure, various types of tonometers are used: contact and non-contact.

Contact tonometry

Increased IOP is a sign of glaucoma

With this measurement method, the tonometer is in direct contact with the surface of the eyeball. Therefore, the procedure is quite painful. The most accurate determination of ophthalmotonus is the applanation method.

Therefore, it is most often used when performing daily tonometry. In this case, the examination is carried out using Maklakov and Goldman tonometers, which measure ophthalmotonus due to the applanate (effort) required to obtain a flat area on a certain area of ​​the corneal tissue of the eye.

During the procedure, the patient is in a supine position. The doctor carefully fixes the tonometer in the central zone of the cornea. Under the influence of weights it is flattened. After contact of the device with the fabric, the borders are painted. This print is copied onto paper and measured. A lesser degree of flattening of the horny tissue of the eyeball indicates a high IOP.

Non-contact tonometry

Pneumotonometry is carried out without direct contact of the device with the surface of the eye. Non-contact tonometers monitor the speed and level of changes in the cornea due to air shocks.

At the beginning of the procedure, the ophthalmologist securely fixes the head of the patient with a special device. The patient opens his eyes wide and looks at the luminous point without interruption. At this time, an air stream is introduced, which changes the shape of the cornea of ​​the eye. The results obtained are analyzed by a computer program.

Pneumotonometry is a painless measurement method and eliminates the possibility of transmission of infection. But the data obtained is less accurate.

For daily tonometry, it is preferable to use contact methods for measuring intraocular pressure.

Indicators for assessing 24-hour tonometry data

Daily tonometry is performed both on an outpatient basis and at home

The results of the examination are assessed by the doctor according to three main parameters:

• Levels of daily intraocular pressure curves.
• The analysis is carried out for each eye separately. In a healthy person, the level does not exceed 27 mm. rt. Art.
• Maximum daily variation.
• To determine this indicator, the difference between two measurements of intraocular pressure within one day is calculated. In the absence of pathologies, this difference does not exceed 4 mm. rt. Art.
• Amplitude of daily curves.
• The doctor calculates the difference between the highest and lowest intraocular pressure during the day.
• A value not exceeding 5 mm is acceptable. rt. Art.

To obtain more informative results, the ophthalmologist takes into account some other parameters. Namely:

1. asymmetry between the eyes (value does not exceed 5 mm);
2. parallelism between the curves of daily intraocular pressure fluctuations;
3. type of curves.

Let's look at the last indicator in more detail.

Main types of daily curves

Daily intraocular pressure curves can be of different types. This is explained by the rise and fall of indicators at specific times during the day. Based on this, four groups of daily curves can be distinguished.

1. Straight curve. This group is characterized by the highest
   ophthalmotonus in the morning, and the lowest in the evening.
2. Reverse curve. In this case, on the contrary, the maximum
   pressure is observed in the evening hours, and the minimum is observed in the morning. It should be remembered that with this type of curve, intraocular pressure can reach a peak in the “extrametric” period, that is, after 20.00.
3. Daily curve (single-humped). This type differs most
   high ophthalmotonus during the day with low pressure in the morning and evening.
4. Directional curve. Intraocular pressure during the day
   reaches a maximum of two times. Therefore, the shape of this curve is two-humped.

With a single-humped and double-humped curve, ophthalmotonus, as a rule, also reaches a maximum during “extrametric” hours: from 9.00 to 12.00 or from 12.00 to 17.00, respectively.

Analysis of the results of daily tonometry

Daily tonometry is carried out using contact and non-contact methods

At the end of daily tonometry, a detailed analysis of the data obtained is carried out. The doctor calculates the average morning, day and night measurements, as well as the range of fluctuations.

In a healthy person, the amplitude of daily changes in intraocular pressure does not exceed 2-3 mm. rt. Art., in rare cases – 4-5 mm. rt. Art.

Deviation from this norm, recording of daily high blood pressure (over 26 mm Hg) indicate the development of glaucoma. It should be remembered that single facts of increased IOP on the daily curve are not always associated with this disease. They may be a consequence of measurement errors, weather conditions, patient experiences and other circumstances.

Thus, daily tonometry allows the doctor to determine the presence of glaucoma in a patient at the initial stage of development of the disease. The examination is carried out, as a rule, in stationary conditions, which allows maintaining the objectivity and accuracy of the results.

Timely detection of the disease and monitoring the effectiveness of therapy using this method increase the patient’s chances of completely preserving the visual function of the eyes. To avoid serious eye diseases, it is necessary to systematically undergo examinations in an ophthalmology office.

Measuring intraocular pressure with the IGD-02- indicator in the video:

In glaucoma, tonometry is an important diagnostic method of examination. This is especially important in the early stages of the disease, since functional disorders are not yet expressed to an sufficient degree and do not allow timely diagnosis, help with treatment tactics and assessment of the prognosis. The onset of pathological changes can be determined by a decrease in the coefficient of ease of outflow. It is these rearrangements that subsequently lead to the development of degenerative and dystrophic processes that affect the structures of the eye. By performing regular tonometry, the doctor can easily monitor the effectiveness of the prescribed treatment and, if necessary, adjust the therapy.

Daily tonometry is the most indicative technique, as it allows you to determine even the slightest changes in the level of intraocular pressure. If tonometry is carried out correctly and the results are correctly assessed, then the method of measuring intraocular pressure does not play a big role. To do this, you can use either a Maklakov tonometer, a Goldmann appalanation tonometer, or a non-contact tonometer.

During daily monitoring, it is necessary to determine the pressure level at least three times. Ideally, the first measurement can be taken early in the morning, before the patient gets out of bed. In this regard, it is most effective to carry out daily monitoring of intraocular pressure in stationary conditions. If daily tonometry is performed on an outpatient basis, it is better to measure pressure over several days (about five times in total).

Based on the results of the study, a curve of pressure fluctuations is constructed, which may look different. The nature of the curve is determined by peaks and valleys in the level of intraocular pressure depending on the time of day. These types can be divided into several main ones:

1. A straight tonometry curve is accompanied by maximum ophthalmotonus in the morning, and minimum in the evening.
2. The reverse type, on the contrary, is recorded when the level of eye pressure is high in the evening and low in the morning.
3. The diurnal curve is characterized by high pressure during the day and low pressure in the morning and evening.
4. The directional curve has two peaks of intraocular pressure, that is, it is double-humped.

Glaucoma detection

During daily tonometry, intraocular pressure is measured three times. The stationary examination method is preferable in this case, since the first measurement is made at 6-8 in the morning, when the patient has not yet gotten out of bed. The other two pressure measurements are performed during the day and evening (from 6 to 8 p.m.). To make the data more objective and reliable, measurements should be taken several days in a row.

After this, the average value of morning, evening, daytime pressure and the amplitude of fluctuations are calculated. During normal operation of the organs of the optical system, daily fluctuations should not exceed 5 mm Hg. if the values ​​are higher, the risk of developing glaucoma increases. A very significant sign is an increase in intraocular pressure above 26 mm Hg. (regardless of the time of day). If such rises are recorded several times, then we are talking about glaucoma.

Cost of daily tonometry

In our ophthalmology center, the price for daily measurement of intraocular pressure (morning/evening) is 1,000 rubles.

Tonometric studies are very important in glaucoma, especially in the early stages, when functional impairment is essential for making a diagnosis, assessing the prognosis and choosing a treatment regimen. It is the decrease in the coefficient of ease of outflow that indicates the beginning of processes that subsequently lead to degenerative and dystrophic changes in the structures of the eye. Tonometry also allows you to monitor the effectiveness of the treatment and correct it in time.

The most indicative of suspected glaucoma is daily tonometry. When carried out correctly and analyzed the data obtained, various tonometry methods are equally effective: using a Maklakov tonometer, a Goldmann appalanation tonometer, or other methods, including non-contact ones.

Daily tonometry includes at least three IOP measurements throughout the day. Ideally, the first measurement should be taken in the morning, before the patient gets out of bed. For this reason, this study is most effective and revealing if the patient is in a hospital. Daily tonometry performed on an outpatient basis will be most objective if the patient visits an ophthalmologist to measure IOP three to five times a day for several days.

The IOP fluctuation curve can have different shapes. Moreover, its character is determined by peaks and drops in fluid pressure at different times of the day. Daily curves are conventionally divided into:

1. direct (ophthalmotonus is at its maximum in the morning and at its minimum in the evening);
2. reverse (peak IOP occurs in the evening hours, while in the morning it is lower);
3. daytime (the maximum level of intraocular pressure is observed during the day, and in the morning and evening it has lower values);
4. directional (IOP indicators reach their peak twice a day, the curve has a two-humped shape).

Detecting glaucoma using 24-hour tonometry

The intraocular pressure measurement scheme for daily monitoring includes three measurements. It is most advisable to conduct such an examination in a hospital setting. The first measurement must be taken from 6 to 8 am before the patient gets out of bed. Subsequent measurements are taken in the middle of the day and in the evening between 18:00 and 20:00. Monitoring is carried out over several days to obtain a sufficient amount of objective data.

Based on the obtained indicators, the average values ​​of morning, daytime and evening IOP, as well as the amplitude of fluctuations, are calculated. Normally, the daily range of these fluctuations should not exceed 5 mmHg. Art. If higher values ​​are detected, this indicates a high likelihood of glaucoma. Even more indicative is the rise in intraocular pressure at any time of the day above 26 mmHg. Art. Such jumps, repeatedly identified, reliably confirm the presence of glaucoma.

Nourishing the eye and maintaining its shape ensures normal eye pressure. It may change if various diseases occur or as a result of fatigue. At the same time, the person experiences discomfort and suffers from headaches. In order to detect violations in time, tonometry should be done regularly. In this case, it is possible to see deviations in time, prescribe treatment and prevent the occurrence of irreversible dysfunction of the most important sensory organ - the eye.

What is tonometry?

Tonometry is a test that measures intraocular pressure (IOP). This test is done to check for eye diseases, such as glaucoma, which occurs due to damage to the optic nerve and can cause blindness. may be damaged due to the accumulation of fluid that does not circulate properly.

To measure, a tonometer is used, which shows the resistance of the cornea to pressure.

At the moment, intraocular pressure is measured using one of the three most common methods:

Non-contact tonometry;

Finger tonometry;

Tonometry according to Maklakov.

Some tonometry methods are quite simple, while others, in turn, require the use of expensive equipment.

Ocular tonometry according to Maklakov is considered more accurate than eye pressure. But often you have to use other methods. For example, in case of a large flow of patients or in cases where direct contact with the eye is prohibited due to indications, non-contact eye tonometry is performed.

This method is based on the reaction of the cornea of ​​the eye. Air pressure is created on it. Non-contact tonometry is carried out only by specialists - an optometrist or ophthalmologist. Because this method is painless, there is no need to use local anesthetic drops during the procedure.

Non-contact eye tonometry is a quick and simple process for measuring eye pressure. First, the patient places his chin on a special stand and looks into the slit lamp. A doctor sits in front of him and shines a bright light. Using special equipment, he delivers a small air blow to the patient's eye. It records ocular pressure measurements related to the exposure of the cornea to light, which changes shape during the procedure. The duration of the procedure is only a few seconds.

If necessary, the doctor can repeat this procedure several times for each eye.

Non-contact tonometry is often used to check intraocular pressure in children and LASIK patients. It should be recalled that this method has no complications and is easily tolerated by patients.

Why is tonometry needed?

Non-contact tonometry is not used to detect glaucoma, but only to monitor the effectiveness of its treatment. That is, such a regular procedure provides specific information about whether intraocular pressure corresponds to the threshold set by the doctor or not.

During a regular examination with an ophthalmologist, intraocular pressure is also checked. This makes it possible, if elevated levels are detected, to prescribe treatment in a timely manner and prevent glaucoma.

How to prepare for tonometry

Before the procedure, you need to remove your contact lenses. It is also necessary to remember that contact lenses can only be put on 2 hours after tonometry. It is recommended to take glasses with you.

The doctor must be informed whether any relatives have had glaucoma. You should also ask your doctor what risk factors exist that contribute to the development of this disease, and tell them if you have any.

Before the procedure, it is better to relax and remove tight clothes from your neck. For tonometry data to be as accurate as possible, it is necessary:

• Do not drink more than 0.5 liters of liquid 4 hours before the procedure.
• Do not drink alcohol during the last 12 hours.
• Do not smoke marijuana for 24 hours before testing.

The following factors may also affect the accuracy of the results:

1. Previous eye surgery or laser vision correction.
2. The cornea is irregularly shaped.
3. Blinking during testing.
4. Eye pain or eye infection.

Tonometry results

Normal eye pressure is different for each person. It usually gets higher immediately after a person wakes up. Frequent changes in intraocular pressure are common in people who have glaucoma.

Experts have noticed that females have slightly higher eye pressure than males. But for almost all people it increases with age.

Intraocular pressure is considered normal if tonometry readings are in the range of 10-21 hectogram millimeters. If it rises above 21 millimeters per hectogram, you should immediately consult a doctor. Such people are at risk, because these indicators may indicate the development of glaucoma.

Tests using various tonometers can be done several times a year, during regular examinations by a specialist. If eye tonometry shows high blood pressure, you should not worry prematurely. It is better to conduct several more tests using other methods of examining the condition of the eye.