Daily tonometry. Non-contact tonometry: preparation, examination and results

This study is mandatory when the presence of glaucoma is established for the first time.

The value of daily tonometry

• Allows you to confirm or deny the presence of the disease in case of suspected glaucoma;
• Helps to assess how fit new eye drops to the patient;
• Helps to assess the dynamics of pressure changes and the effect after surgical treatment glaucoma.

How this study is conducted

Usually, daily measurement of intraocular pressure (IOP) is carried out using one of the two most popular methods: contact tonometry according to Maklakov or non-contact pneumotonometry.

• The number of measurements for a limited number of days must be at least three in the morning and three in the evening;
• Measurements should be taken daily, but an interval of several days is also allowed;
• It is desirable that the pressure in the eye be determined every time at about the same time;
• If you are already using antiglaucoma drops, then it is necessary to measure intraocular pressure before instilling them, and not after.

What daily tonometry can show

• Pressure fluctuations during the day. The difference between morning and evening measurements within 4 units is considered normal. An increase in this difference may indicate the presence of glaucoma. Some characteristics such jumps allow the doctor to suspect a connection between increased intraocular pressure and other diseases.
• The difference in pressure between the right and left eye. The acceptable difference is 3 units. If this figure is higher, then glaucoma can be suspected. This applies to cases when the diagnosis is made for the first time. When the presence of increased intraocular pressure is confirmed and treatment is prescribed, the difference in pressure figures between the right and left eyes can be even greater: everything will depend on the target pressure, which is determined by the doctor. At different stages of glaucoma, the target pressure may differ.
• Pressure response to the prescribed therapy regimen (selected drops and the number of instillations per day).
• Objectively confirm the fact that IOP consistently exceeds normal values, or vice versa, remains within normal limits.

The cost

The average price for this procedure is 1200-1300 rubles. The cost consists of the recommended number of procedures and the frequency of their performance per day. Typically, with multiple IOP measurements, each individual measurement will cost less than monitoring the pressure in the eye, which is done once during an ophthalmologist visit.

The price of daily tonometry is influenced by the way it is carried out (non-contact method or, for example, tonometry according to Maklakov), as well as the devices, devices and consumables used. The measurement itself is usually carried out by a qualified nurse, but maybe - the doctor himself. The evaluation of the results is always carried out by a doctor.

Eye tonometry is a research method that is used in ophthalmology to measure intraocular pressure and is characterized by high accuracy. This method has a number of indications, but in the presence of certain conditions it is not carried out. Tonometry allows you to identify the presence of pathologies that can provoke a deterioration in vision and even cause its complete loss.

What is eye tonometry

Eye tonometry is a procedure during which intraocular pressure readings are obtained. It provides for determining the degree of structural violations eyeball under conditions of external exposure to the cornea.

When evaluating indicators, one millimeter of mercury is taken as a unit of measurement.

This diagnostic measure should be performed by persons over 40-45 years old who have a predisposition to the development of diseases of the organs of vision. Tonometry is performed at least 1-2 times a year.

This manipulation is performed using an apparatus that acts on the cornea. With its help, indicators are measured in the morning and evening. The specialist determines the difference between them and identifies the existing violations.

Indications

Tonometry is necessary for indications such as:

Tonometry is also carried out when the patient complains of frequent pain in the eyes, reddening of the cornea, constant lacrimation.

Contraindications

The diagnostic procedure is not performed with the following indications:

• severe myopia;
• corneal pathology;
• bacterial processes in the area of \u200b\u200bthe eyeball;
• traumatic lesions of the structures of the eyes;
• severe mental disorders, in which the patient is aggressive;
• intolerance to anesthetics (during tonometry, drugs with anesthetic effect are instilled into the eyes);
• viral eye lesions.

Manipulation is not carried out if the patient is under the influence of alcohol or drugs.

How to prepare for the procedure

Before the prescribed manipulation, in order to obtain a reliable result, it is necessary to refuse alcoholic beverages. 4 hours before the measurement, refuse to take liquid.

Preparation for tonometry of the organs of vision is as follows:

• remove contact lenses and take off glasses;
• remove everything that squeezes the neck area (scarf, jewelry, clothes from a high neck), since in this case the pressure on the veins increases;
• drops with anesthetic effect are instilled into the eyes.

After that, they begin to perform the manipulation.

Methods of conducting

In medicine, there are several main methods of tonometry.

Contactless

In this way, the condition of the cornea is assessed by means of an air flow. As the name suggests, there is no contact with the organs of vision, which ensures that there is no risk of infection.

The event is held in different ways:

• using the indicator. An apparatus is used that applies pressure to the eyeball through the eyelid. At the moment of touch, the device determines the indicators of deformation of the tissue of the organs of vision;
• using a tono pen that resembles a normal latex-tipped pen. The definition of indicators occurs through a soft contact lens... This electronic device is necessary if the patient's cornea is injured or affected;
• using a pneumatic device. The device operates by a stream of air supplied directly to the cornea.

Tonometry without eye contact takes no more than a minute.

Palpation

This method is carried out as follows: the patient turns his gaze to any point that is below. At this time, the specialist is fixed with index fingers over the cartilage. upper eyelid and in turn, gently apply pressure to the eye with his index fingers.

In the course of the study, the necessary data are obtained by assessing the degree of eye compliance. The denser the eye, the higher the pressure, the softer the lower.

Tonometry according to the method of Dr. Maklakov

This diagnostic method was discovered at the end of the 19th century and is still used today.

For research, a cylindrical metal tonometer with a wide base and a weight is used.

The essence of this diagnostic method is as follows: a weight of 5, 10 or 15 g is placed on the previously anesthetized cornea, on which the paint is applied. They are left for one second.

On contact, a surface imprint is formed.

The weights are fixed in the holder during installation. To estimate the diameter of the prints, use rulers.

The higher the pressure, the smaller the contact area of \u200b\u200bthe tonometer with the organ of vision. If the pressure is low, then the opposite is true.

Tonometry according to Goldman

To assess the indicators, a device is used that interacts with the cornea and the eyeball. To improve visibility, use a slit lamp.

The degree of pressure is determined using a scale that is installed on the device.

Impression tonometry

This diagnostic method is required when the cornea is curved and it is not possible to assess the state of the organs of vision over a large area.

Impression tonometry is also known as the Schiotz method.

The procedure is performed by pressing on the eyeball with a rod. Before carrying out, anesthetic drops are instilled.

The amount of indentation is determined in linear terms, and then, using special nomograms, is converted into millimeters of mercury.

Daily tonometry

Daily tonometry is a method in which pressure is measured sequentially, several times. In this case, the study is carried out at least three times a day for several days, usually 7-10, less often 3-4 days.

The minimum number of intraocular pressure measurements during the examination period is 6 times.

The first measurements are performed in the early morning, from 6 to 8 hours, while the patient is in bed. After the measurements are taken in the middle of the day. The last measurement took place in the evening, from 18 to 20 hours.

Measurements should be taken every day at the same time.

To measure the level of intraocular pressure, different types of tonometers are used: both contact and non-contact.

Norm for tonometry of the eye

With ophthalmotonometry, the level of intraocular pressure is assessed based on normal values.

Under normal conditions, it is in the range of 10-21 mm Hg. Art.

If the results are even a few units higher than the norm, then the patient is referred for additional research activities, since there is a risk of developing glaucoma.

It is possible to say exactly about the presence of such a disease if, as a result of the measurement, a result of 27 mm Hg was obtained. Art.

Increased intraocular pressure

The phenomenon can be of a different nature:

• transitory. The pressure rises once, for a short time, and then returns to normal;
• labile. Indicators change periodically, but constantly return to normal;
• stable. The pressure is increased regularly, the disorders progress.

This condition is characterized by such signs as:

• pain syndrome extending to the temples and the area above the eyebrows;
• ruptures of blood vessels in the organs of vision, provoking the appearance of red spots on proteins;
• rapid fatigability of the organs of vision during reading and other activities that require their stress;
• blurred vision after sleep.

Increased rates provoke glaucoma, but this phenomenon can also provoke retinal detachment and the development of optic neuropathy.

Decrease in intraocular pressure

The drop in the level is associated with factors such as detachment of the retina of the eye, anomalies in the development of the eyeball, and surgical operations performed on the organs of vision.

The manifestations of deviation include severe dryness of the mucous membrane of the eye, frequent blinking, which brings discomfort, and a gradual decrease in visual indicators.

Complex pathologies are accompanied by drooping of the eyeballs.

When the pressure drops clinical picture is absent for a long time, but vision is gradually reduced.

With prolonged retention of indicators at a level below the norm, the organ of vision becomes smaller. Over time, this becomes visible to the naked eye.

Eye tonometry is a method for assessing intraocular pressure indicators. This diagnostic method allows you to identify the development of such a dangerous pathology of the organs of vision as glaucoma. Tonometry is carried out in different ways, using contact and non-contact equipment.

It is considered one of the most important indicators of the state of our organs of vision. With the modern rhythm of life, the risk of various diseases the eye only grows. Therefore, the measurement of ophthalmotone 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, it is required to take measurements 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 - measurement of IOP at least 3 times a day

Daily tonometry is a procedure for systematic measurement of 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, violations of ophthalmotonus do not appear immediately. But it can be carried out at a shortened rate 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 a hospital and on an outpatient basis. But it is preferable to conduct an 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 a malfunction that gradually results in deterioration or complete loss of vision. This disease can occur in a person at any age. At the same time, doctors cannot definitely name the reasons for the development of glaucoma.

Typically on early stages the disease is almost asymptomatic. Therefore, a routine inspection does nothing. Increased intraocular pressure may indicate an ailment. 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, and predict possible risks and consequences, as well as control 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 in the early morning from 6 am to 8 am, while the patient is in bed. Then ophthalmotonus is 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 for 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 daily tonometry is used to track the effectiveness of treatment in a patient with an established diagnosis of glaucoma, then certain conditions must be observed. Namely:

1. take IOP measurements in the morning and evening hours at the same time;
2. do not dig in before tonometry antihypertensive drugsto determine the pressure at the end of drug action.

Thus, daily tonometry allows you to establish:

• the level of ophthalmotonus in the right and left eye;
• daily fluctuations in IOP;
• the 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 method of measurement, the tonometer is in direct contact with the surface of the eyeball. Therefore, the procedure is quite painful. The most accurate is the definition of ophthalmotone 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 the ophthalmotonus due to the applanate (force) required to obtain a flat area over a certain area of \u200b\u200bthe eye's horny tissue.

During the procedure, the patient is in a supine position. The doctor carefully fixes the tonometer in the central area of \u200b\u200bthe cornea. Under the action of the weights, it flattens. 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 corneous tissue of the eyeball indicates a high IOP.

Non-contact tonometry

Pneumotonometry is performed without direct contact of the device with the surface of the eye. Non-contact blood pressure monitors monitor the speed and level of changes in the cornea when the air is pushed.

At the beginning of the procedure, the ophthalmologist reliably fixes the patient's head 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 admitted, which changes the shape of the cornea of \u200b\u200bthe eye. The obtained results 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 the data of daily tonometry

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

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

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

Let us dwell on the last indicator in more detail.

The main types of daily curves

Daily curves of intraocular pressure can be different kind... This is due to the ups and downs in indicators at specific times during the day. Based on this, four groups of diurnal 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 - in the morning. It should be remembered that with this type of curve, intraocular pressure can reach a peak during the "extrametric" period, that is, after 20.00.
3. Daily curve (one humped). This type is most different
   high ophthalmotonus during the day with low pressure in the morning and evening.
4. Directional curve. Intraocular pressure during the day
   reaches a maximum two times. Therefore, the shape of this curve is two-humped.

With a one-humped and two-humped curve, the ophthalmotonus, as a rule, also reaches a maximum during the "extrametric" hours: in the period 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 by contact and non-contact methods

At the end of the daily tonometry, a detailed analysis of the data obtained is carried out. The doctor calculates the average indicators of 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, fixing the daily high blood pressure (over 26 mm Hg) indicate the development of glaucoma. It should be remembered that single facts of an increase in IOP on the daily curve are not always associated with this disease. They can be the result of measurement errors, weather conditions, patient experiences, and other circumstances.

Thus, daily tonometry allows the doctor to establish the presence of glaucoma in a patient for another initial stage development of the disease. The survey 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 control of the effectiveness of the therapy carried out in this way increase the patient's chances of complete preservation of the visual function of the eyes. To avoid serious eye diseases, it is necessary to systematically undergo examinations in an ophthalmological office.

Measurement of intraocular pressure by indicator IGD-02- in the video:

For daily tonometry, a Maklakov tonometer, a Goldman applanation tonometer, or various types of non-contact tonometers are used. For screening purposes or for home use the patient himself can be recommended a transpalpebral tonometer of the PRA-1 type (Ryazan instrument-making plant).

When analyzing tonometry data, the absolute IOP figures, daily fluctuations and the difference in ophthalmotonus between the eyes are taken into account. Daily fluctuations in IOP, as well as its asymmetry between two eyes in healthy individuals, are usually within 2-3 mm Hg. and only in rare cases do they reach 4-6 mm Hg. If glaucoma is suspected, daily tonometry is performed without the use of antiglaucomatous antihypertensive drugs. The total number of measurements, as a rule, is at least 3 in the morning and 3 in the evening. They can be conducted discretely, with a break for a week or 10 days.

When checking the effectiveness of the drug regimen in patients with an established diagnosis of glaucoma, daily tonometry is performed under the following conditions: IOP is measured in the morning and evening before instillation of antihypertensive drugs to determine the pressure level at the end of the drops.

In tonographic studies, the most important are IOP data (P 0 is the norm - up to 21 mm Hg) and the outflow ease coefficient (the norm for patients over 50 years old is more than 0.13).

Water-drinking or positional samples are used to indirectly assess the ease of the outflow of high-blood fluid. The patient is asked to drink a certain amount of liquid (usually 0.5 liters) in a short period of time (usually 5 minutes), then laid on his stomach with his eyes closed for 30-40 minutes and the IOP is measured during the first hour. If the IOP rises by 5 or more units, the sample is considered positive.

For the integral assessment of ophthalmotonus, it is necessary to distinguish between:

Statistical norm of IOP

The concept of tolerant IOP

· "Target pressure"

The statistical norm of true IOP (P 0) is from 10 to 21 mm Hg, tonometric IOP (P t) is from 12 to 25 mm Hg.

Tolerant IOP is a term introduced by A.M. Vodovozov in 1975. It already refers directly to the glaucomatous process and denotes the level of ophthalmotonus, which does not have a damaging effect on the internal structures of the eyeball. Tolerant IOP is determined using special unloading functional tests.

Finally, the term "target pressure" has only recently been introduced into practice. "Target pressure" is determined empirically, taking into account all the risk factors present in a given patient, and, like the tolerant one, should not have a damaging effect on the eyeball. The definition of "target pressure" is the result of a detailed examination of each individual patient.

The goal is to achieve such a level of IOP, at which there is no decay of visual functions, taking into account other risk factors. In everyday practice, it is accepted that "target pressure" is achieved by reducing the initial IOP level by at least 30%.

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

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

• direct - when the ophthalmotone indicators are maximum in the morning and minimum in the evening;
• reverse - when intraocular pressure is lowered in the morning and increased in the evening;
• daytime - a very rare case when the ophthalmotonus values \u200b\u200bare maximum during the daytime;
• incorrect - when the measurement of pressure inside the eyeball can be presented during the day as a two-humped curve.

Detection of glaucoma using daily 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 eye tonometry is performed in a glaucoma dispensary or hospital. During the study, the average morning and evening values \u200b\u200bof the eye pressure level and the amplitude of fluctuations between these values \u200b\u200bare calculated. The normal range of such fluctuations should not be higher than 5 mm Hg. Otherwise, glaucoma is assumed.

During daily tonometry, intraocular pressure rises above 26 mm Hg are of great importance. With their repeated identification, we can talk with a high degree of certainty about the development of glaucoma in a patient.