RU2421122C1 - Method of training relative accommodation - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to ophthalmology. Patient is shown on plane at minimal viewing angle image of two crossing lines with pairs of located at different distance in pairs similar rings with optotype-numbers along entire lines. Constant state of vergence is controlled by user's sensation of binocular image in form of three lines, the medium of which is sensed by patient as being located vertically. Patient is made to move central look fixation along said lines from the nearest pair of optotype-numbers to the most distant one. Procedure is carried out daily, course lasts 7-10 days.

EFFECT: invention makes it possible to increase efficiency of relative accommodation training, reduce procedure labour intensiveness.

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Description

The invention relates to medicine, namely to ophthalmology, and is intended to train relative accommodation.

Relative accommodation is a change in the focusing ability of the eye with a fixed reduction in the eyes - vergence. It is one of the important functional indicators in the study and restoration of the visual system of patients with progressive myopia.

Myopia (myopia) is the most common visual impairment. In the world there are more than a billion short-sighted people. Complicated myopia is one of the main causes of disability due to eye diseases.

In the pathogenesis of progressive myopia, one of the key factors is the mismatch between the strength of accommodation and the visual work performed at close range [Avetisov E.S. Myopia.-M .: "Medicine", 1999, p.154]. With weakened accommodation, long-term work at close range becomes an unbearable burden for the eyes. In these cases, the body is forced to change the optical system of the eyes so as to adapt it to work at close range without the strain of accommodation. This is achieved mainly by lengthening the anteroposterior axis of the eye during its growth and the formation of refraction. The weakness of the accommodative apparatus may be due to congenital morphological inferiority of the ciliary muscle, its lack of fitness or the result of exposure to general diseases of the body. The reason for the weakening of accommodation is also insufficient blood supply. It is well known that muscle activity is a powerful activator of blood circulation. With the development of axial myopia, the incentive to accommodation is lost due to the approach of the further point of clear vision, which in turn leads to a decrease in the load on the ciliary muscle and the development of its training. Under these conditions, an excessive load on the ciliary muscle during visual work at close range can lead to its spasm. Spasm of accommodation also causes further progression of myopia.

The work of accommodation is characterized by two indicators. The possibility of changing the refraction of each eye individually is measured by absolute accommodation. But when objects are fixed with two eyes in parallel with accommodation, vergence changes (degree of convergence of the eyes: convergence - inside, divergence - outside), so the convergence tension increases the force of absolute accommodation. Since binocular vision is natural for the physiology of visual perception, the degree of change in accommodation with constant, fixed vergence is measured by another indicator - relative accommodation. Thus, relative accommodation (OA) is independent of convergence performance. With nearsightedness, the further point of clear vision approaches the eye, the need for absolute accommodation decreases, and the convergence remains the same - an imbalance in work occurs, so relative accommodation is of greater clinical importance [Avetisov E.S. Myopia.-M .: "Medicine", 1999, p.23]. In relative accommodation, two indicators are distinguished: the positive part (OA +) - how much more accommodation can strain (volume, reserve, reserve of accommodation) and the negative part (OA-) - how much accommodation can be relaxed (the spent part of accommodation) when two eyes are fixed on a single object from a distance of 33 centimeters (the average distance of work near).

Monitoring and restoring relative accommodation is one of the key pathogenetic points in the treatment of progressive myopia.

Known methods of training absolute accommodation such as "mark on the glass" [Avetisov ES Myopia. M .: “Medicine”, 1999, p.211-212], which affect the level of recovery of relative accommodation only indirectly, by increasing the strength of the ciliary muscles, but with fixed vergence, the focus mechanism changes, since there is no effect of convergence on accommodation.

A known method of training relative accommodation [Matz K.A. New methods for training the ciliary muscle with weakened accommodation ability. // Abstract of the dissertation ... Ph.D., M., 1973]. Training is conducted on an outpatient basis, using several pairs of glasses or a special apparatus with a set of interchangeable lenses. The patient reads a text (usually fiction) from a distance of 33 centimeters, with glasses that completely correct the lack of refraction into the distance. To this optical correction, he is additionally added with -0.5D every 3 minutes, until the submaximal accommodation voltage that the patient suffers. Next, additional optical correction is reduced every minute by 0.5D to 0 and positive lenses are added + 0.5D every 3 minutes, until submaximal relaxation of accommodation, and reduced by 0.5D every minute. The training course consists of 15-20 sessions of exercises, each session lasts 30-40 minutes. If the stock of relative accommodation is not achieved as a result of the first course, then the courses are repeated at intervals of 1-2 months until the effect is obtained.

The disadvantages of the method are:

1. Low dynamics. During one session, the patient only strains and relaxes the ciliary muscle once, that is, training is carried out by tonic tension, while a dynamic load is preferable for the development of muscle strength and performance.

2. Long training duration: one session lasts 30-40 minutes.

3. The high cost of treatment: the price of one set of glasses is at least 1000 rubles, the price of the device with lenses arranged in an automated system (Forbis) is 60,000 rubles.

4. The complexity of treatment: to organize the treatment system, 1 nurse is required for 3-4 patients, treatment of 1 patient takes an average of 30-40 minutes, so in one 8-hour working day 1 nurse in 1 room can take no more than 30 person, and for 1 month - to conduct a full course of treatment for no more than 50 patients. Given that treatment should be repeated at least every 6 months, in 1 year 1 nurse in 1 myopic office can treat only 300 people. Given the prevalence of myopia (15.7% in Russia), the implementation of high-quality regular treatment with this method of training becomes difficult to achieve.

5. The lack of the possibility of consolidating the achieved results: for training, it is the relative (and not absolute) accommodation at home that currently does not exist.

The objective of the invention is to increase the effectiveness of training relative accommodation, cheaper and less labor intensive, as well as expanding the functionality of the method.

The technical result is achieved by the method of training relative accommodation by tension and relaxation of accommodation with a constant state of vergence, characterized in that the patient is shown on a plane at a minimum viewing angle an image of two crossed lines with pairs of equally spaced identical pairs of rings with optotypic numbers along the entire length of the lines, while the constant state of vergence is controlled by the patient’s sensation of a binocular image in the form of three lines, the middle of which the patient feels it is located vertically, and they force the patient to shift the central fixation of gaze along these lines from the nearest pair of clearly visible optotype types to the most distant one, and the procedure is carried out for 10-15 minutes, until the sensation of visual fatigue appears, daily for 7-10 days.

The invention is illustrated by drawings, in which Fig. 1 shows a diagram of a device for training relative accommodation, Fig. 2 shows a spatial picture perceived by a patient during preplanar fusion of optotypes, Fig. 3 - the same, at a planar fusion.

The device (Fig. 1) contains a sheet of paper 2000 × 297 mm in size placed on the table with the image of two straight intersecting lines 1 and 2, the distance between the ends 3 and 4 closest to the patient’s eyes is equal to the average interpupillary distance and is 56 mm. The intersection point of 5 lines is at a distance corresponding to the linear equivalent of 3.0D (diopter) - 333 mm from the patient’s eyes. The observation height is determined empirically as the minimum above the image plane, which makes it possible to observe each of the rings, and is 50 mm. Along the lines, identical rings 6 are arranged in pairs with optotypes placed in them. As optotypes, the proposed method uses numbers (optotype) to denote the value of refraction when they are observed from points 7 and 8 located above points 3 and 4. This allows the accommodation to be determined by the value of a clearly distinguishable optotype. The size of the optotype type in each pair corresponds to 100% visual acuity when observed from a distance corresponding to the indicated refraction. Since the farthest rings are located at an acute angle to the axis of view, which makes it difficult to observe, the upper half of each of the rings with an optotype is cut out and raised above the plane perpendicular to the axis of observation. The distance of each optotype number along line 1 to point 7 and along line 2 to point 8 corresponds to the linear refraction equivalent indicated by this optotype number. In this case, adjacent pairs of rings to point 5 are located at a distance equal to the linear equivalent of 0.5D, and after point 5 - at a distance equal to the linear equivalent of 0.1D. This is established experimentally and is due to a change in the linear equivalent of refraction in the areas of pre- and plane-to-plane merging of optotype numbers.

The method is as follows.

The patient is asked to look with each eye along lines 1 and 2. Since the lines intersect at point 5, corresponding to 3.0 D, this ensures constant convergence, while the patient has a feeling of three lines, with rings “put on” on them, located in front of the image plane (pre-plane fusion zone) - further than point 5 (Fig. 2) and beyond the image plane (plane-fusion zone) - closer to point 5 (Fig. 3).

When preplanar merge (figure 2) the left eye from point 7 feels line 2 tilted to the left, and line 1 - vertical, the right eye from point 8 feels line 1 tilted to the right, and line 2 - vertical. In this case, the sensations of vertical lines from each eye merge into the sensation of a single vertical line 9.

When flatter merging (figure 3), the left eye from point 7 feels line 2 tilted to the left, and line 1 - vertical, the right eye from point 8 feels line 1 tilted to the right, and line 2 - vertical. In this case, the sensations of vertical lines from each eye merge into the sensation of a single vertical line 9.

The sense of "verticality" of the lines guarantees a constant state of vergence. The perception of the near rings with optotypic numbers felt as “lower” 10 occurs with a maximum accommodation voltage, the perception of distant ones felt as “upper” rings 11 (Fig. 2), with a minimum.

The lines in the images allow you to control the optimal position of the observer relative to the plane of their location: each eye looks along its line, stereo perception should give a feeling of a strictly vertical midline - this is a guarantee of stable vergence. The perception of the adjacent line with each eye gives the sensation of two more lines. Thus, the sensation of three lines is a guarantee of binocular perception. Rings are necessary to enhance the effect of stereo perception due to the inclusion of corresponding receptive fields of the retina, for which the round shape of the object is optimal. The diameters of the rings are selected mathematically so as to give a feeling of the same size of the rings along the entire vertical of the perceived pattern, which helps to simulate the verticality of the midline. The number of rings is maximum, ensuring a minimum change in accommodation when observing each subsequent series of optotype numbers: in the preplanar fusion zone - in 0.1D increments, in the preplanar fusion zone - in 0.5D increments.

Relative accommodation training is carried out on the device, Fig. 1, by shifting the gaze from the closest optotype to the farthest and back for 10-15 minutes a day for 7-10 days. The criterion for the maximum duration of one lesson is the appearance of a subjective feeling of eye fatigue and a decrease in the amplitude of accommodation (as with ergography). Considering that the bulk of patients are children, a game computer program has been created to train relative accommodation that allows you to record the accommodation operation by the correct perception of test objects (we use "gratings" according to Snellen). In order not to have to “lay” the monitor horizontally, you can turn the tilt limiters in the monitor stand 180 °. To increase the stability of perception of the stereographic picture, by including additional corresponding and disparate points of the retina, the number of lines with rings in the image on the monitor can be increased, which creates the feeling of a whole “fan” of vertical lines. If necessary, the patient can continue training at home using a computer or, if not possible, using stereographic pictures printed on a sheet of paper.

In our practice, not a single patient was encountered who would not be able to perceive stereographic images. For weak convergence, for training in stereographic fusion, we use prisms with a base to the nose or an ophthalmic compensator with a prism and slit-like diaphragm that opens only one line for each eye. Clinical testing was performed on 200 patients. No complications or side effects were detected. The method of restoring relative accommodation through the use of the proposed training has no contraindications that are available when restoring accommodation using the methods of electrostimulation, electrophoresis, reflexology. The long-term results of maintaining the volume (reserve, reserve) of relative accommodation were tracked for 3 years. The treatment process is cemented by a clear statement of the goals, objectives and criteria for monitoring the effectiveness of training. The average increase in relative accommodation for a 7-10-day course of 10-15 minute classes, without the use of other methods of treatment, is 3.8 ± 2.5D. For 3 years of observation after a single course in clinical conditions and subsequent classes at home, more than 90% of patients maintain and even increase the volume (reserve, reserve) of relative accommodation.

Thus, the proposed invention allows with minor material and labor costs to increase the effectiveness of training relative accommodation.

Claims (1)

A method of training relative accommodation by tension and relaxation of accommodation in a constant state of vergence, characterized in that the patient is shown on a plane at a minimum viewing angle an image of two crossed lines with pairs of equally spaced pairs of identical rings with optotype numbers over the entire length of the lines, while the constant state of vergence they control the patient’s sensation of a binocular image in the form of three lines, the middle of which the patient feels located vertically, and cause the patient to translate the central fixation of the gaze along these lines from the nearest pair of clearly visible optotype numbers to the most remote, and the procedure is carried out for 10-15 minutes daily for a course of 7-10 days.

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