A method for converting curvature axis to equivalent sphere

Abstract

The application relates to the field of ophthalmology and provides a method for converting curvature eye axis into equivalent spherical lens, which comprises the following steps: detecting the value of corneal curvature K through a corneal curvature instrument; detecting the value of eye axis AL through an eye axis measuring instrument; finding a reference line a at the eye axis rate ratio reference scale of a conversion mechanism according to the age of a detector; finding the value b of the eye axis AL on an eye axis calibration scale, moving a first mark part on an eye axis curvature calculation scale to the value b, and reading the value c of the eye axis curvature calculation scale at the value a; finding the value c on a curvature calibration scale, moving the value c on the curvature calibration scale to the reference line a; finding the value d of the corneal curvature K on the curvature calibration scale, moving a second mark part to the value d; and reading the value SE of the reference line a on an SE calibration scale. The application combines the axis rate ratio (AL / CR) reference value of emmetropia people of different ages to quickly convert the method of equivalent spherical lens. The application solves the technical problem of time-consuming and labor-consuming in obtaining accurate equivalent spherical lens when establishing a student refractive development file.

Description

Technical Field

[0001] This invention relates to the field of ophthalmology, and more particularly to a method for converting curvature axial length to equivalent spherical lens. Background Technology

[0002] Myopia among children and adolescents in my country is showing a high incidence and younger age trend, seriously affecting their physical and mental health and becoming a focus of attention for the whole society. Regular vision screenings for students on campus and the establishment of refractive development records not only allow parents to understand their children's vision status in a timely and comprehensive manner, but also to monitor the development of their children's eyes and visual function, enabling early detection, early intervention, and early control of vision problems. Axial length (AL), corneal curvature (K), and spherical equivalent (SE) are core indicators for measuring the refractive development of adolescents. Axial length and corneal curvature can be quickly and accurately measured on campus using automated corneal curvature meters and axial length meters. However, while spherical equivalent can be measured automatically using computerized refractometers, the measurement error is relatively large due to the accommodation factor of the human eye, making it impossible to accurately reflect the student's true refractive status. Accurate measurement of spherical equivalent requires students to undergo comprehensive refraction and cycloplegic refraction at a specialized hospital, which is time-consuming and labor-intensive, and parents cannot immediately and accurately understand whether their child has myopia, hyperopia, or other refractive problems and give them sufficient attention. Summary of the Invention

[0003] Therefore, to address the aforementioned problems, this invention proposes a method for calculating the equivalent spherical lens based on curvature and axial length. This solves the technical problem of the time-consuming and labor-intensive process of obtaining accurate equivalent spherical lenses when establishing student refractive development records.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A method for converting curvature axial length to equivalent spherical lens includes the following steps:

[0006] (1) The value of corneal curvature K was detected by a corneal curvature meter;

[0007] (2) The axial length (AL) value was detected using an axial length measuring instrument;

[0008] (3) Based on the age of the tester, find the reference line a at the axial length ratio reference ruler of the conversion mechanism;

[0009] (4) Based on the axial length AL value b obtained by the axial length measuring instrument, find the axial length AL value b on the axial length calibration ruler, slide the axial length curvature calculation ruler, move the first mark on the axial length curvature calculation ruler to b, and read the value c of the axial length curvature calculation ruler at a.

[0010] (5) Find the value c on the curvature scale, and move the curvature scale so that the value c on the curvature scale moves to the reference line a;

[0011] (6) According to the actual curvature K value d obtained by the keratometer measurement, find the value d of the corneal curvature K on the curvature scale, move the SE scale, and move the second mark part to d;

[0012] (7) Read the value SE of the reference line a on the SE scale, that is, SE = 337.5*AC / AL-K, wherein 337.5 is a constant in corneal diopter, D = 337.5 / r;

[0013] The conversion mechanism comprises a frame body, an eye axis ratio reference scale, an eye axis scale, a slidable eye axis curvature calculation scale, a slidable curvature scale, and a slidable SE scale are arranged on the frame body, the eye axis curvature calculation scale is provided with a first mark part, and the SE scale is provided with a second mark part; The eye axis scale and the eye axis curvature calculation scale are logarithmic scales, and the multiplication and division operation is realized.

[0014] Further:

[0015] In the method (1), it is judged whether the value of the corneal curvature K is in the normal range value, the normal value of the corneal curvature K is 39D-48D, and the average is 43D, if it is in the normal value, continue to the next step; If it is not in the normal value, the examiner needs to check the comprehensive optometry or mydriatic optometry.

[0016] In the method (2), it is judged whether the value of the eye axis AL is in the normal range value, the normal value of the eye axis AL is 22-27mm, and the average is 24mm, if it is in the normal value, continue to the next step; If it is not in the normal value, the examiner needs to check the comprehensive optometry or mydriatic optometry.

[0017] In the method (8), if the SE is in the normal value, the detector is normal, if the SE is not in the normal value, it indicates that the detector has significant refractive error.

[0018] It also includes an emmetropia reference table.

[0019] The first mark part is arranged at the scale of 33.75.

[0020] The second mark part is arranged at the scale of 0.

[0021] The first mark part and the second mark part are long strips, the end of the first mark part is close to the eye axis scale, and the end of the second mark part is close to the curvature scale.

[0022] Second sliding grooves are arranged at the top and the bottom of the frame body respectively, a sliding block is slidably arranged in each second sliding groove, and a reference bar is connected between the two sliding blocks, and the reference bar is a reference line a.

[0023] The frame body is provided with three first sliding grooves, and the axial curvature scale, the curvature calibration scale and the SE calibration scale are respectively slidably arranged in the first sliding grooves.

[0024] By adopting the foregoing technical scheme, the present application has the following beneficial effects:

[0025] The present application combines the axial ratio (AL / CR) reference value of emmetropia people of different ages, can quickly convert the equivalent spherical mirror, first detects the value of corneal curvature K and the value of axial AL, detects the corneal curvature K and the axial AL, which are objective indexes, and the measurement is very fast, only a few seconds are needed, the value can be quickly detected, and the value is accurate; the reference line a is found at the axial ratio reference scale of the conversion mechanism, that is, the parameter of AC is found, the values of 337.5*AC / AL are calculated by the axial ratio reference scale, the axial calibration scale and the axial curvature scale, and the value of SE is calculated by moving the curvature calibration scale and the SE calibration scale; the ages of students in the same grade are almost the same, so the reference line a only needs to be adjusted once when detecting the students in the same grade, the value of corneal curvature K of the normal range of the same age and the detected value of axial AL are not much different, even if the value of corneal curvature K and the detected value of axial AL are not in the normal range, a relatively small distance needs to be slid, so after each measurement, the ophthalmologist only needs to slide a relatively small distance to quickly obtain the value of the equivalent spherical mirror SE, so as to preliminarily judge whether the student has myopia, hyperopia or the like; the present application does not need to spend much time in measuring the refractive state, only needs to first detect the value of corneal curvature K and the value of axial AL, so as to quickly obtain the value of SE, and only needs to measure the refractive state of the student with problems, so that the detection efficiency is greatly improved; at the same time, the conversion mechanism is fast, simple and convenient to detect, does not need to be connected to a power source, can fully adapt to outdoor detection, is faster and simpler to calculate than a calculator, only needs to be gently pushed, does not need to be pressed by hand, and does not need to look at the screen, so as to reduce the fatigue of the detector; further, the present application can also detect the value of corneal curvature K and the value of axial AL, so as to judge whether the corneal curvature and the axial AL are in the standard range, the data detected is more, and the detection is more accurate; further, the emmetropia reference table can enable the ophthalmologist to directly see the standard values of different ages; further, the first marking part and the second marking part are in a strip shape, so as to reduce the measurement error and make the measurement more accurate; further, the reference strip can enable the ophthalmologist to accurately and quickly read the value of SE. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a structural schematic view of the conversion mechanism of the present application;

[0027] Figure 2 is Figure 1Structure diagram of the structure of the conversion mechanism with the marks a, b, c and d;

[0028] Figure 3 Structure diagram of the structure of another state of the conversion mechanism;

[0029] Figure 4 Structure diagram of the structure of the cover of the conversion mechanism;

[0030] Figure 5 Structure diagram of the cover. DETAILED DESCRIPTION

[0031] The present application will be further described in conjunction with the drawings and specific embodiments.

[0032] Reference Figures 1 to 5 The embodiment provides a method for converting the curvature of an eye axis into an equivalent sphere, comprising the following steps:

[0033] (1) The value of the corneal curvature K is detected by a corneal curvature instrument, and it is determined whether the value of the corneal curvature K is within a normal range; the normal value of the corneal curvature K is 39D-48D, and the average is 43D; if the value is within the normal range, the next step is continued; if the value is not within the normal range, the examiner needs to perform comprehensive refraction or mydriatic refraction;

[0034] (2) The value of the eye axis AL is detected by an eye axis measuring instrument, and it is determined whether the value of the eye axis AL is within a normal range; the normal value of the eye axis AL is 22-27mm, and the average is 24mm; if the value is within the normal range, the next step is continued; if the value is not within the normal range, the examiner needs to perform comprehensive refraction or mydriatic refraction;

[0035] (3) According to the age of the examinee, the reference line a is found at the eye axis rate reference scale 2 of the conversion mechanism;

[0036] (4) According to the value b of the eye axis AL obtained by the eye axis measuring instrument, the value b of the eye axis AL is found on the eye axis calibration scale 3, the eye axis curvature calculation scale 4 is slid, the first mark part 40 on the eye axis curvature calculation scale 4 is moved to the position b, and the value c of the eye axis curvature calculation scale 4 at the position a is read out;

[0037] (5) The value c is found on the curvature calibration scale 5, and the curvature calibration scale 5 is moved so that the value c on the curvature calibration scale 5 is moved to the reference line a;

[0038] (6) According to the actual curvature K value d obtained by the corneal curvature instrument, the value d of the corneal curvature K on the curvature calibration scale 5 is found, and the second mark part 60 on the SE calibration scale 6 is moved to the position d;

[0039] (7) The value SE of the reference line a on the SE calibration scale 6 is read out, that is, SE = 337.5*AC / AL-K, wherein 337.5 is a constant in corneal diopter, D = 337.5 / r;

[0040] (8) Method (8), if SE is within the normal value, the detector is normal, if SE is not within the normal value, it indicates that the detector has significant refractive error.

[0041] The conversion mechanism comprises a frame body 1, an eye axis ratio reference scale 2, an eye axis calibration scale 3, a slidable eye axis curvature calculation scale 4, a slidable curvature calibration scale 5, and a slidable SE calibration scale 6 are arranged on the frame body 1, the eye axis ratio reference scale 2, the eye axis calibration scale 3, the eye axis curvature calculation scale 4, the curvature calibration scale 5, and the SE calibration scale 6 are arranged in order from bottom to top, the eye axis curvature calculation scale 4 is provided with a first marking part 40, the first marking part 40 is arranged at a scale of 33.75, the SE calibration scale 6 is provided with a second marking part 60, the second marking part 60 is arranged at a scale of 0, the first marking part 40 and the second marking part 60 are long strips, the end of the first marking part 40 is close to the eye axis calibration scale 3, the end of the second marking part 60 is close to the curvature calibration scale 5, and the first marking part 40 and the second marking part 60 are colored; the eye axis calibration scale 3 and the eye axis curvature calculation scale 4 are logarithmic scales, which realize multiplication and division operations, the frame body 1 is provided with three first sliding grooves 10, the eye axis curvature calculation scale 4, the curvature calibration scale 5, and the SE calibration scale 6 are respectively and slidably arranged in the first sliding grooves 10, and a normal eye reference table is further included. The top and the bottom of the frame body 1 are respectively provided with second sliding grooves 11, a sliding block 12 is slidably arranged in each second sliding groove 11, and a reference bar is connected between the two sliding blocks 12, and the reference bar 7 is a reference line a.

[0042] The frame body 1 can be a frame structure, a plate structure, or other structures, which are specifically arranged according to the situation.

[0043] The first marking part 40 and the second marking part 60 can also be triangular or other structures, and different colors can be used, which will not be described here.

[0044] The eye axis ratio reference scale 2, the eye axis calibration scale 3, the eye axis curvature calculation scale 4, the curvature calibration scale 5, and the SE calibration scale 6 can also be arranged in order from top to bottom, or other arrangement modes can be used, which are specifically arranged according to the situation.

[0045] The reference bar 7 can be a strip, a pointer, or other structures, or other structures, or not be arranged, which is specifically arranged according to the situation.

[0046] The second sliding grooves 11, the sliding blocks 12, and the reference bar 7 can also not be arranged, which is specifically arranged according to the situation.

[0047] The normal eye reference table has a standard range of corneal curvature of each age group, a standard range of eye axis, and a numerical value of the reference line a, which is a known table and is specifically arranged according to the situation.

[0048] The corneal curvature instrument and the ocular axial measuring instrument are well-known instruments and will not be described here.

[0049] Reference Figure 4 And Figure 5 A cover 13 can be arranged on the frame 1, the cover 13 is provided with an observation window 14, part of the scale is shielded, the reference strip 7 is arranged on the observation window 14, visual interference can be better avoided, the cover 13 can also adopt other structures, and the specific arrangement is based on the situation.

[0050] The conversion mechanism of the application can also be arranged as a disc structure, the ocular axial rate reference scale 2, the ocular axial calibration scale 3, the ocular axial curvature calculation scale 4, the curvature calibration scale 5 and the SE calibration scale 6 are arc-shaped or circular structures and can be rotatably arranged, and the structure occupies less space and is more convenient to operate.

[0051] Although the application is specifically shown and introduced in combination with the preferred embodiments, it should be understood by those skilled in the art that various changes can be made in form and details without departing from the spirit and scope of the application defined in the appended claims, and all these changes are within the protection scope of the application.

Claims

1. A method for converting curvature and axial length to equivalent spherical lens, characterized in that: Including the following methods: (1) The value of corneal curvature K was detected by a corneal curvature meter; (2) The axial length (AL) value was detected using an axial length measuring instrument; (3) Based on the age of the tester, find the reference line a at the axial length ratio reference ruler of the conversion mechanism; (4) Based on the axial length AL value b obtained by the axial length measuring instrument, find the axial length AL value b on the axial length calibration ruler, slide the axial length curvature calculation ruler, move the first mark on the axial length curvature calculation ruler to b, and read the value c of the axial length curvature calculation ruler at a. (5) Find the value of c on the curvature calibration ruler and move the curvature calibration ruler so that the value of c on the curvature calibration ruler is moved to the reference line a; (6) Based on the actual curvature K value d obtained by the corneal curvature meter, find the corneal curvature K value d on the curvature calibration ruler, move the SE calibration ruler, and move the second mark to d; (7) Read the value of reference line a on the SE calibration ruler, that is, SE = 337.5 * AC / AL - K, where 337.5 is a constant in corneal refractive power, and D = 337.5 / r; The conversion mechanism includes a frame on which are mounted an axial length ratio reference ruler, an axial length calibration ruler, a slidable axial length curvature calculation ruler, a slidable curvature calibration ruler, and a slidable SE calibration ruler. The axial length curvature calculation ruler has a first marking part, and the SE calibration ruler has a second marking part. The axial length calibration ruler and the axial length curvature calculation ruler are logarithmic rulers, enabling multiplication and division operations.

2. The method for converting curvature and axial length to equivalent spherical lens according to claim 1, characterized in that: In method (1), it is determined whether the value of corneal curvature K is within the normal range. The normal value of corneal curvature K is 39D-48D, with an average of 43D. If it is within the normal range, proceed to the next step; if it is not within the normal range, the examiner needs to have a comprehensive refraction or cycloplegic refraction.

3. The method for converting curvature and axial length to equivalent spherical lens according to claim 1, characterized in that: In method (2), it is determined whether the axial length AL value is within the normal range. The normal axial length AL value is 22-27mm, with an average of 24mm. If it is within the normal range, proceed to the next step; if it is not within the normal range, the examiner needs to have a comprehensive refraction or cycloplegic refraction.

4. The method for converting curvature and axial length to equivalent spherical lens according to claim 1, characterized in that: Method (8): If SE is within the normal range, the examinee is normal; if SE is not within the normal range, it indicates that the examinee has significant refractive abnormalities.

5. The method for converting curvature and axial length to equivalent spherical lens according to claim 1, characterized in that: It also includes a reference table for emmetropia (normal vision).

6. The method for converting curvature and axial length to equivalent spherical lens according to claim 1, characterized in that: The first marking is located at a scale of 33.

75.

7. The method for converting curvature and axial length to equivalent spherical lens according to claim 1, characterized in that: The second marking is located at the 0 mark.

8. The method for converting curvature and axial length to equivalent spherical lens according to claim 1, characterized in that: The first marking part and the second marking part are elongated strips, with the end of the first marking part close to the axial length calibration ruler and the end of the second marking part close to the curvature calibration ruler.

9. The method for converting curvature and axial length to equivalent spherical lens according to claim 1, characterized in that: The top and bottom of the frame are respectively provided with second slide grooves, and each second slide groove is provided with a slider that can slide. A reference bar is connected between the two sliders, and the reference bar is reference line a.

10. The method for converting curvature and axial length to equivalent spherical lens according to claim 1, characterized in that: The frame is provided with three first sliding grooves, and the eye axis curvature calculation ruler, curvature calibration ruler, and SE calibration ruler are slidably disposed in the first sliding grooves.

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