How To Measure Eye Pressure: Home Instruments

2024 Author: Rachel Wainwright | [email protected]. Last modified: 2023-12-15 07:39

How to measure eye pressure in adults: devices for measuring intraocular pressure at home and in the clinic

The content of the article:

Methods for measuring IOP
Algorithm for IOP measurement by the Maklakov method
Apparatus for measuring eye pressure at home
Video

How to measure eye pressure? - this question is relevant for many people, because a deviation of this parameter from the norm can lead to a violation of visual function, up to its complete loss.

Eye pressure (intraocular, IOP) is the pressure exerted by the vitreous humor and intraocular fluid on the cornea and sclera. Normally, it is 10–21 mm Hg. Overwork, abuse of alcohol or drinks containing caffeine, certain diseases can lead to its increase (eye hypertension) or decrease (eye hypotension). More often in clinical practice, ocular hypertension is noted. Long-term elevated IOP threatens the development of glaucoma, a disease that leads to optic nerve atrophy and is the main cause of blindness in adults.

Measurement of eye pressure with a Maklakov tonometer in a clinic provides the most accurate result

Eye pressure tends to rise with age. Therefore, all people, starting from 40-45 years old, are recommended to visit an ophthalmologist annually. In the clinic, the doctor will not only determine the visual acuity, examine the fundus, but also measure the eye pressure.

There are devices for measuring eye pressure at home. Their use is recommended for patients suffering from glaucoma or at high risk of developing this disease. Such devices are especially convenient for people who, due to any objective reasons, cannot visit the ophthalmologist's office, where they would have an IOP study.

Methods for measuring IOP

The measurement of intraocular pressure is called tonometry and is carried out using a special device - an ophthalmic tonometer. The following tonometry methods are used:

Finger. The doctor gently presses with the pads of his fingers on the eyeball through the eyelid and assesses the strength of its resistance to pressure. The result obtained cannot be called accurate; it largely depends on the experience of the ophthalmologist. Therefore, this method is used to check IOP very rarely, mainly in the postoperative period, when instrumental exposure to the eyes is undesirable.
Non-contact (pneumotonometry). This method does not involve physical contact between the surface of the eye and the pressure measuring device. It is based on the effect of compressed air flow on the cornea and determination of the degree of corneal deformation in response to this effect. Local anesthesia is not required, and the computer gives the result within a few seconds. The non-contact method is usually used for mass screening of the population. Also, its use is justified in pediatric practice.
Contact. The method is called so because during the study, the surface of the tonometer is in direct contact with the cornea. The cornea is very sensitive to irritation, therefore, in order to prevent pain, local anesthesia must be performed by instilling several drops of an anesthetic solution into the conjunctival sac. Determination of IOP by the contact method provides the most accurate result.

Contact tonometry is subdivided into several subtypes:

applanation. Measurement of IOP is carried out using a Maklakov or Goldman tonometer. The results obtained are suitable for peer review;
dynamic contouring. It is somewhat inferior in accuracy to applanation tonometry. The procedure requires a transpalpebral tonometer;
impression. The method is based on the use of an Icare or Shiotz intraocular pressure tonometer. IOP is measured by this method very quickly and painlessly.

Algorithm for IOP measurement by the Maklakov method

In clinical practice, the Maklakov tonometer is most often used to measure ocular pressure, since it provides a result with a minimum error. The procedure is carried out in the following sequence:

With a swab dipped in alcohol, carefully wipe the tonometer pads, and then dry it with a sterile napkin.
Twice with an interval of three minutes, a 0.25% solution of dicaine or another local anesthetic is instilled into the eyes.
A special paint is applied to the tonometer platform with a thin layer;
The patient is placed on a couch on his back.
The doctor pushes the eyelids of the examined eye and sets the tonometer platform to the center of the cornea.
Under the influence of gravity, the cornea flattens, and the paint from the tonometer platform in the place of its contact with the cornea is partially washed off by the lacrimal fluid.
From the weights, prints of the remaining paint are made on paper impregnated with Nikiforov's mixture (ethyl alcohol and ether in equal proportions) or alcohol.
The value of IOP is judged by the diameter of the resulting print - the smaller it is, the higher the intraocular pressure.
The diameter of the imprint is measured with a special ruler, the divisions of which indicate millimeters of mercury.

Apparatus for measuring eye pressure at home

Modern technologies allow anyone at home to independently measure eye pressure.

For home use, most ophthalmologists recommend the TVGD-02 tonometer. This device measures IOP through the eyelid, so there is no need to anesthetize the cornea before the procedure.

Portable eye pressure monitor TVGD-02 can be used in both adults and children

Portable eye pressure tonometer TVGD-02 can be used in both adults and children.

The principle of operation of this tonometer model is based on the automatic calculation of the vibrations of the cornea in response to exposure to it through the eyelids of electromagnetic impulses.

Contraindications to its use are:

inflammatory eye diseases;
scars or deformation of the eyelids;
scleral pathology;
conjunctivitis.

The TVGD-02 tonometer is supplied in a compact case along with a special control device necessary to assess the correctness of the readings obtained during use.

The TVGD-02 device makes it possible to quickly and painlessly find out the IOP level in both adults and children, however, it should be understood that all portable devices for measuring eye pressure at home have a certain measurement error. Therefore, patients still need to regularly visit an ophthalmologist who will measure IOP by the contact method using a Maklakov tonometer.