RU92777U1 - DEVICE FOR DETERMINING CORNERAL MECHANICAL CHARACTERISTICS - Google Patents

Abstract

 A device for determining the mechanical characteristics of the cornea of the eye, comprising a corneal curvature sensor, a corneal thickness sensor, an intraocular pressure sensor, associated with a computing device that implements the function of calculating a map of the distribution of mechanical stresses in the cornea of the eye.

Description

The utility model relates to medicine, and more particularly to ophthalmology, and can be used to diagnose and control the treatment of diseases of the cornea, in particular keratoconus or corneal ectasia.

Modern diagnostic instruments make it possible to determine with sufficient accuracy the local anatomical changes in the cornea during keratoconus.

A device for measuring the elastic properties of the cornea, which is a set of four Maklakov tonometers (in the book: A.P. Nesterov, A.Ya. Bunin, L.A. Katsnelson // Intraocular pressure, M., 1974. - P. 30- 33.).

These tonometers have different weights, they are mounted on the cornea in turn, and the elastic properties of the cornea are judged by measuring the diameter of the cornea prints on these tonometers. However, the described device does not allow to identify local stresses in the cornea, they do not allow to judge the magnitude of mechanical stresses in the cornea, which does not allow to determine the activity of the process and to accurately establish the diagnosis.

The technical result achieved by the implementation of the utility model is to increase the accuracy of diagnosis of corneal diseases due to the fact that when determining the magnitude of the mechanical stresses of the cornea, the factor of corneal curvature and its thickness is taken into account, and the effect of intraocular pressure is also taken into account. In this case, the calculation results are presented in the form of a map of the corneal stress, which allows us to estimate the distribution of tensile loads in the cornea at local points.

The technical result is achieved by the fact that the device for determining the mechanical characteristics of the cornea of the eye contains a corneal curvature sensor, a corneal thickness sensor, an intraocular pressure sensor associated with a computing device that implements the function of calculating and generating a voltage distribution map in the cornea of the eye.

The utility model is illustrated by drawings.

Figure 1 shows a block diagram of a device for determining the mechanical characteristics of the cornea of the eye;

Figure 2 shows a map of the distribution of curvature of the cornea.

Figure 3 is a map of the distribution of the thickness of the cornea.

Figure 4 is a final map of the normal distribution of mechanical stresses in the cornea.

Figure 5 - map of the distribution of curvature of the cornea with keratoconus.

6 is a map of the distribution of the thickness of the cornea with keratoconus.

Figure 7 shows the resulting map of the stresses of the cornea with keratoconus.

A device for determining the mechanical characteristics of the cornea of the eye contains a corneal curvature sensor 1, a thickness sensor for the cornea 2, an intraocular pressure sensor 3, and a computing device 4.

A keratotopograph can be used as a corneal curvature sensor 1, a keratopachymeter can be used as a cornea 2 thickness sensor, and an ophthalmometer can be used as an intraocular pressure sensor 3. Various types of pachymeters can be used, both optical and ultrasonic. It is also possible to use ophthalmotonometers using various principles for measuring intraocular pressure, both contact and non-contact type.

Using the sensors of curvature and thickness of the cornea, a distribution of the values of the curvature and thickness of the cornea is obtained in the form of maps, then the intraocular pressure is measured. The data obtained from the sensors are transmitted to the computing device 4. Using a computing device in all the corresponding points of the received maps using the Laplace equation calculate the magnitude of the mechanical stress acting over the entire area of the cornea:

σ = PR / 2d (1), where R is the radius of curvature of the cornea;

P - intraocular pressure;

d is the thickness of the cornea.

Then form a map of the distribution of mechanical stresses in the cornea - figure 4.

The resulting map of stress distribution in the cornea allows you to diagnose corneal pathology.

The diagnosis is established by the change in the magnitude of the maximum values of the stress of the cornea and by the deviation of the position of the center of the zones of maximum stresses relative to the center of the map. In Fig.4 is a variant of the normal map of stress distribution in the cornea, Fig.7 is a variant of the distribution of mechanical stresses of the cornea with keratoconus. The higher the maximum values of the stress of the cornea, the higher the likelihood of keratoconus or ectasia of the cornea. According to the position of the center of maximum stresses of the cornea or when it is displaced (Figs. 5 and 7), the localization of the process leading to the development of keratoconus or corneal ectasia is determined.

Claims (1)

A device for determining the mechanical characteristics of the cornea of the eye, comprising a corneal curvature sensor, a corneal thickness sensor, an intraocular pressure sensor, connected to a computing device that implements the function of computing a map of the distribution of mechanical stresses in the cornea of the eye.