Tonometry - Causes, Symptoms and Treatment .MF .

August 12, 2017 17:52 | Diagnosis In Ophthalmology

Tonometry - a method of determining intraocular pressure with the tonometer.Intraocular pressure is expressed in millimeters of mercury.There are two types of tonometry: contact and contactless.


1. Age older than 40 years (healthy persons tonometry should be carried out at least 1 time per year).
2. Glaucoma (tonometry should be carried out at least 1 time in 3 months).
3. Pain in the eyes, frequent headaches.
4. Availability of patients with glaucoma among close relatives.
5. endocrine, cardiovascular and neurological diseases.

Contraindications to contact tonometry:

1. Pathology of the cornea.
2. Viral and bacterial diseases of the eye.
3. Allergies.

contraindications to the use of non-contact tonometry not.

Conducting contact tonometry

Underlying contact tonometry method is based on the principle of flattening the cornea.To do this, use a tonometer of Maklakov, is a hollow metal cylinder weighing 10 g., Inside which there is lead-based.At the ends of the cylinder are two polish

ed area of ​​white glass with a diameter of 1 cm.

Tonometer Maklakova

Before examining doctor (or nurse) rubs the area with alcohol, and then they apply a thin even layer of special paint containing,collargol their composition (or Bismarck brown-), glycerol and distilled water.The paint is applied to the stamp pad touch pad impregnated with dye.Excess ink is removed with a dry cotton swab.For local anesthesia in 3-5 minutes before the test to the patient twice instill 2 drops of p-ra lidocaine with 1 minute interval.

The patient lies down on the couch, face up.The doctor sits at his bedside.

procedure contact tonometry

patient should raise his hand up to his eyes looking straight at the index finger.The doctor gently with one hand pushing the patient's eyelids, and puts the other hand tonometer on the cornea, which is in a special holder.Tonometer must descend vertically, and strictly on the center of the cornea.In this case the cornea is flattened under his weight.At the point of contact of the cornea with a colored area tonometer dye passes to the surface of the cornea, while the paint is still only at the periphery of the site tonometer, and in the center is devoid of dye white circle.The method consists in the fact that the higher the intraocular pressure, the denser the eye, therefore, the smaller corneal flattening tonometer and the lower contact tonometer with the corneal surface and the smaller diameter result in a white circle.Conversely, the lower the intraocular pressure, the greater the contact and the greater diameter of the white circle.Then the doctor measures the pressure of this eye again, turning the tonometer that was used on top of playground.To determine the intraocular pressure in the other eye using another similar cargo, weighing 10 grams.

Adopted first measure the pressure on the right and then the left eye.After the procedure, the eye drops instilled disinfectants (eg, pp furatsilina).

then obtained circles alternately printed on paper previously moistened with alcohol.In this paper should contain the patient's name, date and time of the study, be sure to note any fingerprints obtained from the right eye, and what - to the left.The diameters of circles obtained was measured using a special line that allows you to immediately get the result, expressed in millimeters of mercury.

For this method, the study is considered normal blood pressure 18-27 mm Hg.Art.with the daily fluctuations in the 3-5 mm Hg.Art.(Morning IOP above), so diagnostic purposes tonometry should be carried out in the morning and evening.

contactless tonometry

Non-contact tonometry is performed using a special apparatus that determines the IOP by an air strike.This method is simple, accurate enough and does not require pre-anesthesia.But this requires a special apparatus.

patient sits near the unit, he puts his head on a special stand and looks at a particular point.The device produces a stream of air with a certain force.IOP level depends on the degree of corneal flattening when exposed to this stream.The result of the study shall be submitted to the device screen.

procedure noncontact tonometry

procedure contact tonometry is usually unpleasant for the patient, but it is absolutely painless;non-contact tonometry may cause the patient some discomfort during heavy flow of air in contact with the cornea, which can cause a temporary slёzotechenie;procedure is also painless.

duration of contact tonometry procedure an average of 10-15 minutes;noncontact tonometry procedure takes a few minutes.

Ophthalmologist Odnoochko EA