RU2738861C1 - Method for determining parameters of horizontal-vertical diplopia - Google Patents

Abstract

FIELD: medicine.SUBSTANCE: invention refers to medicine, namely to ophthalmology. An ophthalmic examination is performed. Then he looks at computer monitor screen, on which there is a fixation object in center - white circle on black background. Monocular fields of vision are separated using red and green light filters: a green filter is placed in front of a straight-eyed eye, a red one in front of the mowing eye. A patient with a computer mouse cursor clicks on visible objects on the monitor screen to combine a double image. In place of pressing on the red object, a polar coordinate system appears on the monitor screen, indicating a deflection of the sight line of the mowing eye from the common fixation point and the object offset angle, and in the upper right corner displaying numeric values processed by program with indication of degree of deviation of double image in prism dioptres and object displacement angle in degrees.EFFECT: invention provides broader functional capabilities of the method, shorter duration and high accuracy of determining diplopia parameters.3 cl, 4 dwg, 2 ex

Description

The invention relates to medicine, namely to ophthalmology, and can be used to determine the parameters of horizontal-vertical diplopia.

Binocular diplopia is double vision resulting from strabismus, incorrect displacement of the visual axes of the eyes relative to each other.

Paralytic strabismus, endocrine ophthalmopathy, myasthenia gravis and other nosological forms are some of the most complex forms of pathology of the oculomotor system. These diseases inevitably lead to an asymmetrical position of the eyes, limitation of eye mobility towards the action of the affected extraocular muscle (EOM) and diplopia. Horizontal-vertical (combined) diplopia is a subjective symptom in these disorders and reduces the quality of life of patients, leading to disability, professional limitations, loss of the ability to control transport, performance of precise motor and intense visual work. It is difficult for patients with horizontal-vertical diplopia to explain to the doctor in which direction the double image is displaced, by what amount, therefore, difficulties arise when choosing a prismatic correction.

There is a known method for the study of diplopia, which consists in the fact that the patient is presented with a test object moved along the arc of the perimeter in the form of a luminous vertical strip. The research is carried out in the 8 main meridians. The totality of studies on them forms the field of the patient's binocular gaze, which is recorded on a perimetric map with the field of gaze of a healthy person pre-built on it. According to the answers of the researched in the field of gaze, the zones of double vision and single vision are distinguished. If the patient wears glasses (contact lenses), the study is carried out under conditions of appropriate correction. Determine the area of double vision and the area of single vision in the field of binocular gaze (Authors of the USSR No. N159861, publ. 15.10.1990).

The disadvantages of the known method are its relative accuracy and duration of execution, as well as limited functionality, since neither the nature of double vision nor the distance between double images is determined, and therefore it is impossible to accurately determine the parameters of diplopia and, therefore, to prescribe the correct treatment.

There is a known method for the study of diplopia, which consists in separating the images of the right and left eyes and their combination on a plane using projection coordinateimetry. A patient wearing colored red-green glasses observes a tangent grid in the form of a square from a distance of 1 m. The researcher projects a red round spot at 9 points corresponding to the main directions of gaze with the help of a flashlight. The subject is holding a green one in his hands and he is offered to cover the red spot with his green spot. Since he sees a red spot with one eye, and a green one with the other, in the presence of diplopia, green spots do not coincide with red ones. The researcher puts on the image of the tangent grid the location of the green circles projected by the researcher. The distorted shape of the square indicates diplopia (F.A. Hamburger "Stellungsanomalien" "Der augenarzt" Band III, 1960).

The disadvantage of this method is the impossibility of determining the parameters of diplopia (for example, how the diplopia changes when the gaze moves, the distance between the double images, the angle of displacement of the double image). In addition, this method requires sufficient patient preparation.

A known method for the study of diplopia, which consists in alternating presentation of the test object that appears on the computer screen. Determine the position of fixing the gaze of the eyes on the test object in each of its positions. In this case, the determination of the gaze fixation position is carried out for each eye separately with binocular fixation of the gaze of both eyes of the patient on the test object. The distance between the coordinates of the position of the fixation points of the eyes is taken as the parameters characterizing the state of the oculomotor muscles. The distance in pixels corresponding to the angle of deviation of the gaze fixation point from the position of the test object within 220 arc minutes is taken as the norm. The test object is alternately presented in the center of the computer screen and at least 8 points along its periphery at equal angles and equal time intervals. If the distance displayed by the vector between the positions of the gaze fixation points exceeds the norm, a violation of the function of the oculomotor muscle is diagnosed. In the direction of the vector, the severity of the violation of the functional state of the muscle is assessed (Patent RU 2484760 C1, publ. 20.06.2013).

The disadvantages of this method are the duration of the procedure and the lack of information, since the method assesses not the diplopia itself, but the unfriendliness of the movements of the two eyes.

The closest to the claimed method - the prototype, is a method for determining the parameters of diplopia, including the separation of fields of view using red-green glasses, presentation of luminous objects in different directions of gaze and assessment of the relative position of double images. The patient is presented with a consistently luminous object, for example, on a monitor screen. After presentation of each object, the alignment of double images is achieved, offering the patient to independently align them using the mouse cursor. After presentation of all objects, the quantitative parameters obtained during the study are analyzed: the strabismus angle in the primary gaze position, the degree of unfriendliness, the image rotation angle (torsion), which are measured in degrees (Patent RU 2100956 C1, publ. 10.01.1998).

The disadvantages of this method are the duration, since it takes additional time to analyze the results, as well as lack of accuracy. It is very difficult for a patient with diplopia to combine double images with the mouse cursor. Estimation of the position of double images is therefore highly subjective.

The objective of the invention is to expand the functionality of the method, reduce the duration and improve the accuracy of determining the parameters of diplopia.

The task is achieved by the proposed method, which is as follows.

All patients determine visual acuity according to the Golovin-Sivtsev table without correction and with correction, determine the refraction on an autorefractometer. If the patient has ametropia, the examination is carried out with existing or fitted glasses in a well-lit room.

The patient is placed at a distance of 100 cm from the monitor screen, the head is fixed in an upright position. The patient looks at the monitor screen, on which a luminous fixation object (test object) is sequentially presented in the form of a white circle on a black background (Fig. 1). Determination of the parameters of diplopia is carried out in six diagnostic directions of gaze (in the forward direction, when turning the head to the right - look to the left, when turning the head to the left - look to the right, when looking up and down). Monocular fields of view are separated using red and green light filters: the green filter is placed in front of the direct looking (fixing) eye, the red one in front of the squinting eye. The patient, using the cursor of the computer mouse, clicks on the visible objects on the monitor screen to align the double image (the patient has diplopia, so he sees two objects, the true object is green, the displaced second object is red). For clarity, when you click on a red object, a polar coordinate system is displayed on the monitor screen, indicating the deviation of the line of sight of the squinting eye from the common fixation point and the angle of displacement of the object. In the upper right corner of the monitor (using a computer program), the processed numerical values characterizing the degree of deviation of the double image in prism diopters (pr. Diopters) and the displacement angle of the object in degrees are displayed (Fig. 2). This is especially important when characterizing horizontal-vertical diplopia.

The defining differences between the proposed method and the prototype are:

- monocular fields of view are separated using red and green light filters, with the green filter placed in front of the directly looking eye, and the red one in front of the squinting eye, which makes it possible to reveal the participation (or non-participation) of the squinting eye in binocular vision:

- after presenting the test object, the patient clicks on the visible red and green test objects on the monitor screen with the cursor of the computer mouse to align the double image, which allows you to visually assess the nature (of the same or opposite name) diplopia, thereby determining the type of strabismus by the type of deviation;

- test objects are presented sequentially in six diagnostic directions of gaze, which makes it possible to assess how the parameters of diplopia change when the gaze is moved, thereby identifying the affected extraocular muscle;

- the parameters of diplopia, namely the deviation of the line of sight of the squinting eye from the common fixation point, the angle of displacement of the object and the degree of deviation of the double image, are calculated using a computer program, which allows you to quickly and accurately determine the quantitative parameters of diplopia and select the optimal prismatic correction.

The degree of displacement of the object of fixation relative to the anatomical structures of the eye is taken as the parameters from which the angle of displacement of the object is calculated. The program allows you to calculate the accuracy of the displacement angle of the object up to 1 ° and the force of the required prismatic correction up to 2 pr. Diopters. This reduces the time for further selection of prismatic correction, increases the accuracy of the selection of elastic Fresnel prisms (Fresnel) due to a visual and quantitative assessment of the diplopia parameters.

The method is simple in implementation, does not require special skills from the patient, since you just need to click on the monitor screen with the computer mouse cursor.

A search on the sources of scientific, technical and patent information did not reveal a method identical to the claimed one, and therefore, it can be concluded that the proposed technical solution meets the criteria of "novelty" and "inventive step".

The application of the proposed method is illustrated by the following examples.

Example 1.

Patient P., 55 years old, complained of binocular diplopia vertically and horizontally. Diplopia appeared 1 week ago. From the anamnesis: she has been suffering from diffuse-toxic goiter for 10 years, about 1 month ago she noticed a deterioration in her condition (against the background of stress) and turned to an endocrinologist - an active stage of hyperthyroidism. Appropriate treatment was prescribed.

Ophthalmic examination results:

1. Refractometry (Topcon KP-8100RA autorefractometer, Japan):

OD sph + 1.0 D cyl + 0.50 D ax 155 °

OS sph + 0.5 D cyl + 0.50 D ax 88 °

2. Visual acuity was assessed according to the Golovin-Sivtsev table:

OD 0.85 n.s.

OS 1.0.

The patient was placed at a distance of 100 cm from the monitor screen, the head was fixed in an upright position. The patient was sequentially presented on the monitor screen with a luminous test object in the form of a white circle on a black background. Determination of the parameters of diplopia was carried out in six diagnostic directions of gaze. Monocular fields of view were separated using red and green light filters: green was placed in front of the directly looking eye, red in front of the squinting eye. The patient with the cursor of the computer mouse clicked on the visible objects on the monitor screen to align the double image. When you click on a red object, a polar coordinate system appeared on the monitor screen, indicating the deviation of the line of gaze of the squinting eye from the common fixation point and the angle of displacement of the object. In the upper right corner of the monitor, the quantitative parameters of diplopia were displayed, characterizing the degree of deviation of the double image in sp. Diopters and the displacement angle of the object in degrees.

The study by the proposed method revealed the deviation of the image of the right eye downward - 10 ave diopters and outward - 10 ave diopters by the type of esohypotropia of the same name in the straight gaze position with an object displacement angle - cyclotropy of 220 ° (Fig. 3).

Diagnosis: Endocrine ophthalmopathy, active stage, esotropia, hypotropia of the right eye.

Since the patient was diagnosed with an active stage of hyperthyroidism, surgical treatment is contraindicated, therefore, the patient was prescribed a prismatic correction to eliminate diplopia, selected by the proposed method - 10 ave diopters, base 140 °. Diagnostic control after 1 month, continue treatment with an endocrinologist.

Example 2.

Patient X., 60 years old, complained of binocular diplopia vertically and horizontally.

From the anamnesis: 1 year ago, the patient was injured in a road accident. Was diagnosed with paresis of p. Abducens OS, twice operated for strabismus. After the operations, a double image is saved.

The patient underwent a study similar to example 1. At the first stage, an ophthalmological examination was performed. Refraction was assessed using an autorefractometer (Topcon KP-8100RA, Japan) under physiological conditions:

OD sph - 1.0 D cyl - 0.50 D ax155 °

OS sph - 1.5 D cyl - 0.50 D ax 88 °

Visual acuity was assessed according to the Golovin-Sivtsev table:

OD 0.5 sph - 1.0 = 1.0

OS 0.4 sph - 1.25 = 1.0

The study by the proposed method revealed a deviation of the left eye image upward - 6 ave diopters and outward - 6 ave diopters by the type of esohypertropia of the same name in the straight gaze position with an object displacement angle - cyclotropy 120 ° (Fig. 4). Then the necessary prismatic correction was selected - 6 ave diopters, base 240 °. Diagnostic control after 1 month.

Diagnosis: Operated paresis n. abducens, esotropia, OS hypertropia.

The use of the proposed method will improve the accuracy in determining the parameters of diplopia in patients with horizontal-vertical diplopia, which, in turn, will allow more accurate and quick selection of the necessary prismatic correction to eliminate diplopia, as well as reduce the time of diagnostic examination and the patient's stay in the treatment institution.

Claims (3)

1. A method for determining the parameters of horizontal-vertical diplopia, including the separation of monocular fields of view, presentation of luminous test objects on a computer monitor in different directions of gaze and assessment of the relative position of double images, characterized in that monocular fields of view are separated using glasses with red and with a green light filter, while the green filter is placed in front of the directly looking eye, and the red one in front of the squinting eye, then, after presenting the test object, the patient clicks on the visible red and green objects on the monitor screen with the cursor of the computer mouse to align the double image, then, when you click on a red object, a polar coordinate system is displayed on the monitor screen, indicating the deviation of the line of sight of the squinting eye from the common fixation point and the angle of displacement of the object, while in the upper right corner of the monitor quantitative parameters of diplopia are displayed, characterizing the degree of deviation of the double image, in prismatic d ioptry and object displacement angle in degrees. 2. The method according to claim 1, characterized in that the fixing object is a white circle located in the center of the monitor on a black background. 3. The method according to claim 1, characterized in that the test object is presented to the patient sequentially in six diagnostic gaze directions.

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