RU2703697C1 - Method for assessing visual acuity in healthy preschool children and deaf-mute children - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to ophthalmology. To implement the method of checking visual acuity in preschool children and deaf-mute children, the child is placed at distance of 2–2.5 m from the table, which consists of 2 A4-size sheets on which the optotypes are arranged, height and width of each row should be equal at first line = 35 mm, on second = 17.5 mm, at tenth = 3.5 mm, optotypes gradually decrease in size from top to bottom with indication against each row of corresponding visual acuity. Visual acuity is checked first of the right eye and then of the left eye by indicating the optotype and obtaining a response from the child by using the cards attached to the table. On the first sheet, the tables are arranged in descending order of size of three rows of optotypes, corresponding to visual acuity of 0.1 to 0.3 with pitch of 0.1, and on the second – seven rows of the same optotypes, arranged in descending order of size, corresponding to visual acuity 0.4 to 1.0 with pitch of 0.1. Distance between characters in the row and between lines from top to bottom increases, in 10^th row number of optotypes decreases to 3.

EFFECT: use of the method enables higher accuracy and reliability in verifying visual acuity in healthy preschool children and deaf-mute children.

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Description

Application area

The invention relates to medicine, namely to ophthalmology, and is intended to assess visual acuity in healthy children of preschool age and deaf children.

Analogs of the invention

To date, various methods for checking visual acuity are known, but the most common is the method of checking on a printed table. In preschool children, visual acuity in our country is usually checked according to the Orlova table; Various methods of checking visual acuity are also known: according to a printed table, using a sign projector, using a transparent device, using signs to be displayed on a computer screen, and others. The most common device in our country is S.S. Sivtseva and D.A. Golovin with an apparatus for lighting it (L. S. Urmacher. Handbook of Ophthalmic Optics and Devices, M, 1971, pp. 48-49), which, along with a table composed of Landolt rings, contains a table with letter optotypes. In each row, the sizes of the optotypes are the same, but gradually decrease from the first row to the last 12th. The Golovin-Sivtsev table consists of two halves, one of which contains rows of lines with block letters of the Russian alphabet (H, K, I, B, M, W, Y), and the other with Landolt rings. Landolt rings are rings with a gap directed up, down, left or right. Letters and rings are constructed according to the principle: the ratio between the detail of the sign and the sign is 1: 5. The background of the table is white and the signs are black. The rows in both halves of table 12.

Against each row in the table from the first to the tenth, visual acuity from 0.1 to 1.0 with an interval of 0.1 was noted; the eleventh and twelfth rows correspond to visual acuity of 1.5 and 2.0. The change in the magnitude of the optotypes was performed in arithmetic progression in the decimal system so that when examining from five meters, reading each subsequent line from top to bottom indicates an increase in visual acuity by 0.1.

Criticism of the analogue

The disadvantage of this method is the low accuracy of checking visual acuity. This is due to the following reasons:

- lack of understanding by many children of preschool age of the test objects (optotypes) presented to them - letters, rings, and as a result - refusal to examine;

- many of them may have difficulty perceiving optotypes in the form of letters or abstract figures in various orientations.

- In addition, many children aged 3-7 years experience difficulties with the left-right orientation, necessary for testing the most common Landolt and Snellen optotypes. In this regard, with traditional testing, prerequisites are created for errors and, as a result, insufficiently reliable test results.

- low interest of children in conducting the survey due to the remoteness of the test table by 5 meters and the lack of appeal of optotypes for children;

- Not all characters in the same row are identically recognizable.

- the disadvantage of this method is the impossibility of diagnosing visual acuity for deaf-mute children and the national factor is not calculated (different languages).

The analogue is a method for checking visual acuity according to the Orlova table (Textbook “Eye diseases” under the editorship of T. N. Broshevsky, A. A. Bochkareva, 1983, p. 85), which consists in the following: the child is seated in a darkened room at a distance of 5 meters from the test table fixed in the apparatus for its illumination (Roth apparatus), and the visual acuity is checked first of the right eye, closing the left eye with a shutter, then similarly to the left eye, closing the right eye with a shutter. The Orlova table is a single sheet of paper with a format of 580 × 520 cm, which shows the optotypes (drawings) of different sizes in the form of a star, mushroom, Christmas tree, circle, chicken, car, horse, plane, elephant, motorcycle. Optotypes are grouped in two columns: on the left there are 5 rows, and on the right 7. Optotypes in rows from top to bottom are gradually reduced in size. Visual acuity was noted against each row: from 0.1 to 0.3 in the left column, from 0.4 to 1.0 in the right column. With a visual acuity of 0.1-0.2, there were three optotypes in each row, at 0.3 - four optotypes, at 0.4-0.5 - five, at 0.6-0.7 - six, at 0, 8-0.9 seven, with 1.0 - eight. The table background is white and the pictures are black.

Criticism of the analogue

The disadvantage of this method is the low accuracy of checking visual acuity. This is due to the following reasons:

- the degree of recognition of optotypes of the same series varies markedly and largely depends on the level of development of the child, for example, some optotypes, such as a cock and a horse, a plane and a star, as practice has shown, are similar and often eat children;

- Often the optotypes traditionally used to test visual functions are incomprehensible to children. Images of optotypes are not equally familiar to all children (many children do not call a motorcycle, elephant and mushroom at all). Many of them may have difficulty perceiving optotypes in the form of letters or abstract figures in various orientations.

- the large size of the optotypes and their small number in the first rows of the table reduce the reliability of the responses of the child with visual acuity of 0.2-0.3;

- the principle underlying the tables for adults is not observed, according to which the ratio between the optotype part and the optotype itself is 1: 5;

- the inability to conduct an examination outside the eye cabinet: the table is relatively large; a special lighting device is needed; a minimum distance of 5 meters is required in the examination room. All this makes it difficult to use the table “on the road”, on a business trip, when screening for children of preschool institutions.

- The disadvantage of this method is the inability to diagnose severity! vision for deaf children and is not designed such a factor as the language barrier (different languages).

Prototype

The closest analogue is the method for checking visual acuity according to the Patent of the invention No. 2281685 "Method for checking visual acuity in preschool children" (author Nagorsky P.G.) similar to the tables of Landolt and Snellen:

According to the prototype, when testing visual acuity in preschool children, they mustache: they nod to the child opposite the checklist, which is a series with a set of optotypes that gradually decrease in size from top to bottom, indicating \ against each row of the corresponding visual acuity. Visual acuity is checked first of the right and then of the left eye by pointing to the verification element of the optotype and receiving a response from the child. Before the examination, the child is shown a table from a distance of 30-40 cm. Then they proceed to check visual acuity from a distance of 2.5 meters. The table consists of two sheets of A4 format each. On the first sheet there are three rows of car-stylized optotypes with two test elements with wheels in the form of a closed or torn ring with a different direction of the gap. On the second sheet there are seven rows of the same optotypes. The ratio between the size of the test element and the optotype in the table is 1: 5.

Prototype criticism

The disadvantage of this method is the low accuracy of checking visual acuity. This is due to the following reasons:

- many children aged 3-7 years experience difficulties with the left-right orientation, necessary for testing the most common optotypes. In this regard, with traditional testing, prerequisites are created for errors and, as a result, insufficiently reliable test results.

- The optotype itself in the table of the patent for invention No. 2281685 (author P. Nagorsky) has a larger size relative to the ring.

The purpose of the invention |

To develop a method for assessing visual acuity, providing increased accuracy and reliability when checking visual acuity in healthy preschool children and deaf-mute children.

SUMMARY OF THE INVENTION

To implement the method, you need: a chair, a Rota apparatus with a JEI / JEI table (just evident images) or a sign projector for visual acuity research, a pointer, plastic, metal or cardboard plates (for closing one eye). For deaf-mute children: cards showing the signs of the test chart (when showing a sign, the child must pick up a card with the corresponding image)

The technical task “to examine visual acuity in healthy children and preschool children with deaf-mute children” is as follows: Before starting visual acuity testing, the child is shown a table from a distance of 30-40 cm to familiarize himself with the presented picture (optotype). The child is seated at a distance of 2.5 m from the table JEI / JEI (Fig. 1, 2). The table consists of 10 rows of pictures, the size of which decreases from top to bottom. The left column indicates the distance from which a healthy child should see a row. It is indicated by the letter D (distance) and is expressed in meters. The visual acuity is indicated on the right side of the table, which is indicated by the letter V (visus). Being at a distance of 2.5 meters from the JEI / JEI table, the child should clearly distinguish 10 row. In this case, his visual acuity is 1.0 or 100%. If a child distinguishes only the first line from a five-meter distance, the result is 0.1 or 10%. Further on increasing. The JEI / JEI table is located on two A4 sheets. Vision is considered normal if the child is able to recognize with each eye pictures of the tenth line from a distance of 2.5 meters.

The height and width of each image in the JEI / JEI table should be equal (Fig. 3, 4), on the first line = 35 mm, on the second = 17.5 mm, on the tenth = 3.5 mm.

The bottom edge of the table should be 60 cm from the floor. The JEI / JEI table is placed at the eye level of the child in a vertical plane, so that the average row of signs on the table is approximately at the eye level of the child.

If before contacting a doctor, the child already used glasses or contact lenses, then he must remove them before the examination. To prescribe a new prescription for glasses (contact lenses).

The child should sit straight, calmly, without squinting or bending forward to the JEI / JEI table, which is located at the level of his eyes in a vertical plane so that the middle row of signs on the table is approximately at the level of the child’s eyes. Deaf children should be given cards with images from the JEI / JEI table (Fig. 5). When showing one or another sign, the child raises a card with the corresponding image.

Testing in children causes fatigue earlier than in adults, so it is better to carry out it as follows:

The unexplored eye is previously closed and visual acuity is determined better than the seeing one, and then worse than the seeing eye, if it is known in advance. And if not, then first determine the visual acuity of the right, then the left eye.

The child needs to alternately show pictures, starting from the top row and gradually going down, without showing them in advance.

Only show one or two pictures in each row.

If on any column the child incorrectly named the symbol, you should give him a second attempt.

If he can’t name her, on the second attempt, it is necessary to return to the line up.

The result is evaluated by the column on which the child saw all the images (only one error is made with subsequent correction).

When conducting the inspection, it is important to ensure that the child does not squint and ponders the answer for no more than 5 seconds.

Next, close the second eye and repeat the same procedure.

If the visual acuity is below 0.01, then you need to give the child a sheet of paper with an image in his hand and ask him to name the signs with a distance of 10 cm from the eye level of the child:

“Give the same picture”

"Show me where the flower

“Name this picture”

The JEI / JEI formula is used to study visual acuity below 0.1 and above 1.0.

V (visus) 1 - normal visual acuity

D (distance) - the distance from which the images differ with normal visual acuity

d (distance) - the distance from which the subject sees

V (visus) 2 - visual acuity of the patient

An example of a specific implementation of the method

Example 1

Patient N., five years old, conducted a study of visual acuity according to the Orlova table according to the standard method. The result was recognized as unreliable, since the girl could not name the pictures of a motorcycle and a kettle even of large sizes. The result was recognized as unreliable, since the girl often confused optotypes with the image of an airplane and a star.

The girl was checked for visual acuity by the method proposed as an invention. The table is fixed in the Rota lighting apparatus. Before starting the test, the child was shown the same table from a distance of 30-40 cm to familiarize himself with the pictures. With the correct answers from a close distance, we went over to the test from a distance of 2.5 meters and gave the child cards with images from the JEI / JEI table. When showing one or another sign, the girl raised a card with the image of the corresponding image.

Test results: visual acuity was 0.8 in each eye.

Example 2

Patient A. (deaf-mute) eleven years old, conducted a study of visual acuity according to the Landolt table according to standard methods. The result was invalid, since the boy had difficulty with the left-right orientation, and could not correctly indicate the direction of the rings.

The boy was checked for visual acuity by the method proposed as an invention. The table is fixed in the Rota lighting apparatus. Before starting the test, the child was shown cards with images from the JEI / JEI table from a distance of 30-40 cm to familiarize themselves with the pictures. The boy, when showing a sign, raised a card with the image of the corresponding image.

Features of the invention, distinctive from the prototype

на первом листе таблицы расположены в порядке убывания размера три ряда оптотипов, соответствующие остроте зрения от 0,1 до 0,3 с шагом 0,1, а на втором - семь рядов тех же оптотипов, расположенных в порядке убывания размера, соответствующих остроте зрения от 0,4 до 1,0 с шагом 0,1.

on the first sheet of the table, three rows of optotypes are arranged in decreasing order of size, corresponding to visual acuity from 0.1 to 0.3 in increments of 0.1, and on the second — seven rows of the same optotypes located in decreasing order of size, corresponding to visual acuity 0.4 to 1.0 in increments of 0.1.

Высота и ширина каждого изображения в таблице JEI/JEI должна быть равной на первой строке =35 мм, на второй =17,5 мм, на десятой =3,5 мм.

The height and width of each image in the JEI / JEI table should be equal on the first row = 35 mm, on the second = 17.5 mm, on the tenth = 3.5 mm.

в таблице JEI/JEI увеличивается расстояние между знаками в ряду и между строками сверху вниз, это создает более удобные условия для распознавания знаков и оценки остроты зрения.

in the JEI / JEI table, the distance between characters in a row and between rows from top to bottom increases, this creates more convenient conditions for recognizing characters and evaluating visual acuity.

The positive effect of using the proposed method

It is carried out for all children from 3 years old and to preschool and deaf-mute children: children who have applied for ophthalmological help. There are no contraindications.

The accuracy of checking visual acuity by the claimed method is 54% higher (Fig. 6) than the prototype method according to the Orlova table, which means that the proposed method of checking visual acuity in preschool children is more accurate and reliable than the standard study according to the Orlova table and has a number of advantages .

The developed method is a simpler, accessible, and quicker approximate method for studying visual acuity in healthy preschool children and in deaf children. When researching a new method of visual acuity in children, an understanding of instructions, speed, accuracy of execution, adequacy of action, interest, development result, learning ability are recorded.

можно проверять остроту зрения даже глухонемым детям

visual acuity can be checked even for deaf children

учитывается наличие языкового барьера (разные языки), ребенок не может назвать картинку, требуются переводчик, который не всегда может находиться рядом. Следует дать в руки ребенка карточки с изображениями из таблицы JEI/JEI. При показе того или иного знака ребенок поднимает карточку с изображением соответствующего изображения.

the presence of a language barrier is taken into account (different languages), the child cannot name the picture, an interpreter is required, which may not always be nearby. Cards with images from the JEI / JEI table should be given into the hands of the child. When showing one or another sign, the child raises a card with the image of the corresponding image.

есть возможность проводить обследование вне кабинета окулиста, в домашних условиях, в поездке и при обследовании детей в дошкольных учреждениях.

it is possible to conduct an examination outside the ophthalmologist’s office, at home, on a trip and when examining children in preschool institutions.

The method provides increased accuracy and reliability when checking visual acuity} in healthy children of preschool age and deaf children.

Information taken into account:

Patent No. 2281685 “A method for checking visual acuity in preschool children” (author P. Nagorsky) - prototype.

Claims (1)

A method of checking visual acuity in preschool and deaf children, characterized in that the child is seated at a distance of 2-2.5 m from the table, which consists of 2 sheets of A4 format, on which are located rows of optotypes, the height and width of each row should be equal on the first line = 35 mm, on the second = 17.5 mm, on the tenth = 3.5 mm, the optotypes gradually decrease in size from top to bottom, indicating the corresponding visual acuity against each row, they check the visual acuity first of the right, and then left eye by pointing to the optotype and receiving a response from the child using the cards attached to the table, on the first sheet of the table are three rows of optotypes in decreasing order of size, corresponding to visual acuity from 0.1 to 0.3 in increments of 0.1, and on the second - seven rows of the same optotypes arranged in decreasing order of size, corresponding to visual acuity from 0.4 to 1.0 in increments of 0.1, the distance between characters in a row and between rows from top to bottom increases, in 10 rows the number of optotypes decreases to 3 .

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