RU2573102C1 - Eye dislocation measurement device - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: orbital eye positioning device comprises an Artex facial arc consisting of two movable element systems; the device also consists of two mirror optical elements mounted on the pads secured on the movable element systems and travelling in three planes; side faces of the Artex arc and the movable element systems have metric scales.

EFFECT: using the given invention is expected to provide the more accurate measurement of the eyeball axial reposition in surgical repairs of the orbital cavity.

2 tbl, 3 dwg, 1 ex

Description

The invention relates to medical equipment and can be used in ophthalmology, maxillofacial surgery to measure the displacement of the eyeball during injuries of the orbit. The purpose of the invention is to improve the accuracy of measurement.

To assess the position of the eyeball in the orbit along the anteroposterior axis (exophthalmometry) use tools such as the exophthalmometer Luedde, Hertel, Naugle, Mourits. The most common exophthalmometer in ophthalmic practice is the Hertel exophthalmometer and its various modifications, which are not fundamentally different from the previous ones. The main elements of this exophthalmometer are a system of mirrors reflecting the apex of the cornea, and millimeter lines on each specular optical element. The device is designed in such a way that the points of its support on the skull of the subject, which are also the reference points (zero point of the scale) of the measurement, are the outer edges of the orbits. That is, the distance of the vertex of the cornea of the studied eye is measured relative to the outer edge of the orbit of the same name using a system of mirrors (http://en.wikipedia.org/wiki/Exophthalmometer).

This device can be effectively used in cases of intact bone walls of the orbit, since one of them, the outer one, is the fulcrum of the device.

Injuries of the middle zone of the face often lead to a change in the normal anatomy of the bone orbit, which prevents the use of its structure as reference points during biometrics. In particular, with a traumatic displacement of the zygomatic bone forming the outer wall of the orbit, the support point of the Hertel exophthalmometer also shifts. Accordingly, the axial position of the eye should be estimated relative to the deployed outer edge of the orbit and will be false in this case. To exclude the influence of the position of the outer edge of the orbit on the results of exophthalmometry, Naugel proposed a device having other points of support on the patient’s skull: the infraorbital region (frontal bone) and the infraorbital region (maxillary bone body) (US 345929 Apr. 12, 1994).

Like the Hertel exophthalmometer, this device has several options. But even in this case, with traumatic deformation of the middle zone of the face, including fractures of the zygomatic-orbital complex with displacement of fragments, the above-described problems of installation and orientation of the device on the deployed structures of the skull arise. This problem becomes even more relevant when evaluating measurement results at the pre- and postoperative stage of reconstructive interventions. The restoration of the correct anatomy of the facial skeleton is achieved by reposition of displaced bone structures, which is inevitably associated with a change in the spatial position of the anatomical landmarks, relative to which measurements of the position of the eye are made. Often, metal structures are used to fix repaired fragments of the facial skeleton, which can also change the position of the fixation point of the measuring device (exophthalmometer).

In order to maximize independence from the spatial position of the points relative to which the axial position of the eyeball will be measured, various types of ophthalmometers fixed on the head of the patient using earhooks or a special cap have been proposed (US 7384147 B1, Jun. 10, 2008). The disadvantage of these devices is not sufficiently rigid fixation of the device. The operation of these devices is based on a slightly different principle for determining the position of the eye: the position of the protruding point of the cornea (vertex) of the eye being examined is not estimated, but the surface of the upper eyelid covering the eye. The measurement error using this device is greater than when performing exophthalmometry according to the position of the top of the cornea.

In domestic and foreign literature there are reports on methods for determining the displacement of the eyeball by multislice sections of the CT image of the orbits (RU 2275842 C2, 07.22.2004). For the same purposes, complex bulky stationary devices were developed (SU 1431730 A1, 11/10/1986), which did not receive further widespread use in practice (for the closest analogue we take the Hertel exophthalmometer, which was described above).

The problem to which the present invention is directed is to create a device for measuring eye dislocation, including in patients with deformations of the zygomatic-orbital complex.

The technical result of the proposed device is to increase the accuracy of measuring the axial reposition of the eyeball during reconstructive operations in orbit.

The technical result of the invention is achieved due to the fact that the spatial positioning of the point is first made, relative to which the axial position of the eyeball will be calculated.

The device for measuring the eye dislocation during orbital injuries consists of the Artek front arc, two systems of movable elements (right and left) installed on it, which provide movement in three planes of areas with mirror-optical elements fixed to them, with the help of which the axial position of the eye is determined in orbit (exophthalmos).

This device as the points of fixation of the facial arch on the head of the subject has external auditory canals and nose bridge. The first two support points of the device are unchanged for almost any pathology of the facial skeleton. The position of the third fulcrum (nose bridge) in the event of a change in its anatomical characteristics does not affect the results of measurements. This point only gives additional stability to the position of the device on the head of the subject, which also helps to increase the accuracy of the measurement. Sites with mirror-optical elements fixed on them due to the designed systems of moving elements have the ability to change their position in three mutually perpendicular directions. Each site is set so that its leading edge rests on the outer edge of the orbit of the same name. In this position, the spatial coordinates of each site are recorded using metric scales applied to the outer side surfaces of the Artek front arc and to the details of each moving element system. Next, exophthalmometry is carried out according to a standard method (similar to the study conducted using a Hertel exophthalmometer). The proposed device allows you to:

- to carry out positioning of the outer edge of the orbit in the pre- and postoperative period of reconstructive operations in orbit;

- conduct exophthalmometry relative to the deployed edge of the orbit;

- perform exophthalmometry relative to the edge of the opposite (intact) orbit;

- assess the position of the eye in a vertical plane (hyper- / hypophthalmos);

- knowing the magnitude of the displacement of the outer edge of the orbit - calculate the error of exophthalmos measurements using a publicly available Hertel exophthalmometer and take it into account during subsequent exophthalmometry.

The invention is illustrated by drawings, where in FIG. 1 shows a top view of an apparatus for determining the position of an eye in an orbit, FIG. 2 is a general view of a device for determining the position of the eye in an orbit in a frontal projection, FIG. 3 is a left side view of the device, where 1 is the Artex Facebow arch, consisting of the left 1a and right 1b moving parts, 2 is a screw that fixes the base distance between the ear olives 18 inserted into the external auditory meatus. 19 - a scale of values of the base distance. 6 - mirror-optical element of the exophthalmometer installed on the site 7. 8 - the ebb of the site 7, installed on the edge of the outer wall of the orbit of the subject. 9 - guides along which the platform 7 is moved in a horizontal plane. 10 - a scale of values of the position of the platform 7 in the horizontal plane, applied to one of the guides 9. 11 - a screw that fixes the position of the platform 7 on the guides 9. 12 - the upper structural element, in which the guides 9 are rigidly fixed. element 12 with guides 9 fixed therein and platforms 7 vertically. 16 - upper and lower adjusting nuts, fixing the position of the upper structural member 12 relative to the lower structural member 15 vertically. 14 - a scale of values of the position of the upper structural element 12 (respectively, and the platform 7) vertically applied to the front guide 13. The lower structural element 15 is fixed to the front arc 1. Parts 7, 9, 12, 13, 15 and 16 constitute a structure that provides moving the mirror-optical element of the exophthalmometer 6 in the vertical and horizontal planes. The peculiarity of fixing the lower structural element 15 to the front arc 1 allows the first (and, accordingly, the entire structure) to move relative to the front arc 1 in the sagittal plane. 17 - screw fixing the position of the lower structural element 15 on the front arc 1.

Thus, the mirror-optical element of the exophthalmometer has three degrees of freedom of movement: in the horizontal, vertical and sagittal planes. 3 - plastic nose bridge. 4 - damper mechanism of emphasis on the bridge of the nose. 5 - screw, fixing the position of the damper mechanism of the nose bridge.

A device for measuring the dislocation of the eye works as follows: after loosening the screws 2, the horizontal size of the facial arch is adjusted so that the ear olives 18 are installed in the external auditory canals of the subject. After this, the screws 2 are tightened. After loosening the screw 5, the position of the plastic stop 3 on the nose bridge is adjusted. Thus, the facial arch is fixed on the head of the subject at three points of support. After that, the ebb 8 of platform 7 is installed on the outer edge of the orbit on each side. This is achieved by moving the platform 7 along the front-rear axis, loosening the screw 17; along the vertical axis - rotating nuts 16 (clockwise to move the platform up and counterclockwise - down); along the horizontal axis - loosening the screw 11. This position of the platform 7 has its coordinates along the above axes. The position of the platform 7 along the front-rear axis is estimated on a scale 20, printed on the left feathers 1a and right 1b of the feathers of the facial arch 1. The value indicated on the scale 20 by mark 21 is directly proportional to the distance between the ear olive and the outer edge of the orbit of the same side. The position of the site 7 along the vertical axis is evaluated on a scale 14 plotted on the guide 13. The position of the site along the horizontal axis is estimated on a scale 10 plotted on the guide 9. All values of the position of the platform 7 are entered in a special orbitometry table. After installing the sites on the outer edges of the orbits using the mirror-optical elements 6 determine the axial position of each eyeball in the same orbit - exophthalmometry. Exophthalmometry values are also entered in the orbitometry table.

Example. Patient O., 31 years old. Clinical diagnosis: OD - Mild myopia. OS - Condition after blunt orbital injury. Deformation of the sculoorbital complex. Fracture of the lower, outer walls of the orbit, zygomatic bone. Enophthalmos. Mild myopia. OU - Binocular double vision.

On examination, the patient complains of binocular double vision when looking up, down, out; cosmetic defect of the middle zone of the face due to the retraction of the left zygomatic tubercle, left eye. According to the patient, 18 days before the treatment he was beaten up by unknown persons: he received several blows in the region of the left half of the face, left eye. He did not lose consciousness, there was nausea, vomiting once.

To assess the degree of enophthalmos in the conditions of the deployed zygomatic bone forming the outer edge of the orbit, we used a device for measuring eye dislocation. The orbitometry results are shown in table No. 1, where “Base” is the distance between the ear olives, estimated on a scale of 19, applied to the front surface of the facial arch 1. “AX” - the value of the position of the site in the front-rear direction; “VERT” - vertically and “HORIZ” - horizontally. "EXO" - the value of exophthalmos relative to the edge of the same orbit.

Thus, according to the results of biometrics performed using a device for measuring the displacement of the eyeball during injuries of the orbit, one can note the traumatic dislocation of the outer edge of the left orbit backward, outward and downward. Exophthalmometry values of 17 mm for the right and 16 mm for the left eye reflect the state of enophthalmos on the left at 1 mm. However, taking into account the fact of the dislocation of the edge of the left orbit posterior to 2 mm, we can judge a greater displacement of the left eyeball, i.e. about enophthalmos equal to 3 mm.

The patient in the Department of Maxillofacial Surgery underwent reconstruction of the zygomatic-orbital complex with correction of enophthalmos on the left. The results of performing orbitometry 2.5 weeks after surgery are presented in table No. 2.

According to the results of postoperative research, one can judge the volume of reposition of the zygomatic-orbital complex (outer wall of the orbit) and the eyeball. Exophthalmometry data reflect exophthalmos on the left equal to 1 mm. Given the data on the position of the zygomatic bone (the outer edge of the orbit), it becomes possible to calculate the true difference in the position of the eyes: the postoperative position of the outer wall of the left orbit (against which exophthalmometry is performed) is 1 mm anteriorly to the contralateral side, respectively, the difference in the position of the ophthalmic apples is 2 mm. In the same way, the calculation of the position of the eye as a result of reconstructive surgery in orbit is performed. In this case, it is 5 mm. Knowing the difference in the position of the outer edges of the orbits in a particular patient, it becomes possible to take this value into account when conducting further exophthalmometry using a standard Hertel exophthalmometer.

Claims (1)

A device for determining the position of the eye in the orbit, characterized in that it contains the Artex facial arc, consisting of two systems of moving elements, two mirror-optical elements mounted on platforms mounted on systems of moving elements with the ability to move in three planes, and on the side surfaces Artex arcs and metric scales are plotted on moving element systems.

Images