A fitting method of scleral lens based on different regions of corneoscleral depth

Abstract

The application discloses a scleral lens fitting method based on the sag depth of different regions of the corneosclera, and pre-establishes an optimization interval table of the sag height and base arc curvature radius of an optical zone; an optical device is used to visually scan the corneosclera to generate a basic model of the corneosclera; a first sag height corresponding to the optical zone, a second sag height corresponding to the PCZ, a third sag height corresponding to the LCZ and a fourth sag height corresponding to the SLZ are measured from the basic model; the optimization interval table is called by using the target sag height to obtain the target base arc curvature radius; a scleral lens curve model is constructed on the basic model of the corneosclera; the ring curvature of the scleral lens curve model is adjusted by the sag height change of each region to obtain an optimized scleral lens curve model. The scheme can be adapted to the vision change of a user by simply measuring the sag depth and modeling, and adjusting the base arc curvature radius and the ring curvature according to the new data, thereby providing a very flexible and improved fitting efficiency method, and the effect of vision correction can be significantly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lenses, in particular to a fitting method of a scleral lens based on the sagittal depth of different regions of the corneosclera. BACKGROUND

[0002] A scleral lens landing on the scleral region outside the limbus without contacting the cornea is now available on the market. Specifically, by increasing the diameter of the lens to make the lens larger than the whole cornea, the contact position of the lens on the ocular surface is changed from the cornea to the relatively insensitive sclera, reducing the risk of damage to the cornea and reducing the foreign body sensation of the lens.

[0003] The prior art provides a scleral lens and a fitting method thereof. The sagittal height of the scleral lens is obtained based on the sagittal depth of the anterior segment of the cornea and the sclera close to the cornea, and then the scleral lens is prepared according to the sagittal height of the scleral lens. However, the sagittal height calculated by this fitting method is often single or local, and relative to the complex surface of the cornea, the designed lens shape is single and the precision is poor, which cannot meet the individualized demand of vision correction and the effect of vision correction is limited.

[0004] Therefore, it is necessary to improve the fitting method of the scleral lens in the prior art to solve the technical problem that the effect of vision correction of the lens is limited.

[0005] Invention

[0006] The purpose of the present application is to provide a fitting method of a scleral lens based on the sagittal depth of different regions of the corneosclera to solve the above technical problems.

[0007] To achieve this purpose, the present application adopts the following technical solutions:

[0008] A fitting method of a scleral lens based on the sagittal depth of different regions of the corneosclera, the corneosclera including an optical zone, a PCZ, an LCZ and a SLZ in turn from the middle to the outside, the fitting method comprising:

[0009] S1, pre-establishing an optimization interval table of the sagittal height of the optical zone and the corresponding base arc radius;

[0010] S2, using an optical device to visually scan the corneosclera to generate a basic model of the corneosclera;

[0011] S3, measuring the first sagittal height corresponding to the optical zone, the second sagittal height corresponding to the PCZ, the third sagittal height corresponding to the LCZ and the fourth sagittal height corresponding to the SLZ from the basic model;

[0012] S4, calling the optimization interval table by the target sagittal height to obtain the target base arc radius;

[0013] S5. Based on the target base arc curvature radius, first sag, second sag, third sag and fourth sag, construct a scleral lens curve model on the basic model of the cornea and sclera.

[0014] S6. Adjust the circumduction of the scleral lens curve model by changing the sagittal height of each zone to obtain an optimized scleral lens curve model.

[0015] Optionally, S2 specifically includes:

[0016] S21, an OCT device is used to visually scan the cornea and sclera in the horizontal meridian direction to generate a first model of the cornea and sclera;

[0017] S22, using an OCT device to visually scan the cornea and sclera in a steep meridian direction to generate a second model of the cornea and sclera;

[0018] S23, using the combination of the first model and the second model, establish a basic model of the cornea and sclera.

[0019] Optionally, S3 specifically includes:

[0020] S31, Select the highest point of the basic model of the cornea and sclera as the reference point, and establish a vertical line on the basic model with the reference point;

[0021] S32, the thickness of the tear duct between the cornea and the sclera located in the vertical direction is determined as k; where k is a constant value.

[0022] S33, read the height H1 of the optical area of ​​the first model and the second model along the vertical line to the reference point, respectively, and the first sag = (first model H1) / 2 + (second model H1) / 2 + k;

[0023] S34, respectively read the height of PCZ of the first model and the second model from the reference point along the vertical line direction as H2, and the second sag = (H2-H1) / 2 of the first model + (H2-H1) / 2 of the second model;

[0024] S35, respectively read the height of the LCZ of the first model and the second model from the reference point along the vertical line direction as H3, the third sag = (H3-H2) / 2 of the first model + (H3-H2) / 2 of the second model;

[0025] S36, read the height H4 of the SLZ of the first model and the second model along the vertical line to the reference point, and the fourth sag = (H4-H3) / 2 of the first model + (H4-H3) / 2 of the second model.

[0026] Optionally, k is 0.3 mm.

[0027] Optionally, after S36, the following may also be included:

[0028] S37, determine the overall sagitta, the overall sagitta = (first model H4+k+(H4-H3)) / 2+(second model H4+k+(H4-H3)) / 2.

[0029] Optionally, S5 specifically includes:

[0030] S51, set the chord lengths of the sclera lens corresponding to the optical zone, PCZ, LCZ and SLZ respectively as the first length D1, the second length D2, the third length D3 and the fourth length D4;

[0031] S52, determine the PCZ width, LCZ width and SLZ width of the scleral lens respectively;

[0032] S53, set the first length D1, calculate the second length D2 = D1 + PCZ width * 2; calculate the third length D3 = D1 + PCZ width * 2 + LCZ width * 2; calculate the third length D4 = D1 + PCZ width * 2 + LCZ width * 2 + SLZ width * 2;

[0033] S54, based on the first sag and first length D1, the second sag and second length D2, the third sag and third length D3, and the fourth sag and fourth length D4, the dimensions of the scleral lens corresponding to the four regions of the optical zone, PCZ, LCZ and SLZ are designed to generate the scleral lens size combination.

[0034] Optionally, S54 may be followed by:

[0035] S55, using preset curve rules to plan the scleral lens size combination for scleral lens curve planning, so as to construct a scleral lens curve model based on the corneal and scleral base model.

[0036] Optionally, the first length D1 is 9 mm, the second length D2 is 11.2 mm, the third length D3 is 12.8 mm, and the fourth length D4 is 14.6 mm.

[0037] Optionally, S6 specifically includes:

[0038] S61, the first annular curvature of the cornea corresponding to the optical zone is set to T1, the second annular curvature corresponding to the PCZ is set to T2, the third annular curvature corresponding to the LCZ is set to T3, and the fourth annular curvature corresponding to the SLZ is set to T4.

[0039] S62, calculate T1 = (First Model H1 - Second Model H1) / 2; calculate T2 = (First Model H2 - Second Model H2) / 2 - T1; calculate T3 = (First Model H3 - Second Model H3) / 2 - T1 - T2; calculate T4 = (First Model H4 - Second Model H4) / 2 - T1 - T2 - T3; these four values ​​are calculated using the height data of corresponding areas in the first and second models and through corresponding operations. These torus values ​​will help design scleral lens curves that better fit the shape of the eye.

[0040] S63, the posterior surface of the rigid scleral lens is designed with annular curves in each zone. The sagitta of each zone in the flat meridian direction is set as the first sagitta, the second sagitta, the third sagitta, and the fourth sagitta; the sagitta of each zone in the steep meridian direction is set as the first sagitta + T1, the second sagitta + T2, the third sagitta + T3, and the fourth sagitta + T4. The corresponding sagitta are designed from two different spatial directions to allow the designed scleral lens to better adapt to the geometry of the cornea and sclera.

[0041] S64, set the circumduction of each zone of the sclera to T, and adjust the circumduction of the sclera to the sclera curve model by adjusting the sag of each zone in the flat meridian direction and the sag of each zone in the steep meridian direction to obtain an optimized sclera to the sclera curve model.

[0042] In summary, by calculating the torus curvature, a highly personalized scleral lens that conforms to the geometry of the eye is established to improve its wearing comfort and the quality of vision correction.

[0043] Compared with existing technologies, this invention has the following advantages: Based on the sagittal height measurement of the four regions of the cornea and sclera, a highly personalized scleral lens curve model can be obtained, ensuring that the scleral lens can adapt to the vision correction needs of various users. Furthermore, the designed scleral lens has better fit between the cornea and sclera, which is beneficial to improving the user's wearing comfort. Simultaneously, by adjusting the circumcurvature of the scleral lens curve model through the base arc curvature radius, the curve is optimized to obtain better correction results. In summary, this solution can adapt to changes in the user's vision by simply measuring the sagittal depth and modeling, and then readjusting the base arc curvature radius and circumcurvature based on new data. This provides a highly flexible method that improves fitting efficiency and can significantly improve the effect of vision correction. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] The structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0046] Figure 1 This is a flowchart illustrating the fitting method in this embodiment;

[0047] Figure 2 This is a schematic diagram of the scleral lens curve model of the fitting method in this embodiment;

[0048] Figure 3 This is a schematic diagram showing the positional relationship between the scleral lens and the cornea / sclera in the fitting method of this embodiment;

[0049] Figure 4 This is a schematic diagram of the wearing of the scanning scleral lens on the cornea in the fitting method of this embodiment. Detailed Implementation

[0050] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0051] In the description of this invention, it should be understood that the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component positioned centrally in the connection.

[0052] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0053] This invention provides a method for fitting scleral lenses based on the sagittal depth of different regions of the cornea and sclera. The cornea and sclera 10 includes optical zones 11, PCZ, LCZ, and SLZ sequentially from its center outwards. The method is characterized by comprising:

[0054] S1, pre-establish the optimization interval table of the sag of optical region 11 and the corresponding base arc curvature radius R0;

[0055] S2, use optical equipment to visually scan the cornea and sclera 10 to generate a basic model of the cornea and sclera 10;

[0056] S3, measure the first vector height corresponding to the optical zone 11, the second vector height corresponding to the PCZ, the third vector height corresponding to the LCZ, and the fourth vector height corresponding to the SLZ from the basic model.

[0057] S4, the target base arc curvature radius R0 is obtained by calling the optimization interval table through the target elevation;

[0058] S5. Based on the target base arc curvature radius R0, the first sag, the second sag, the third sag, and the fourth sag, construct a scleral lens 20 curve model on the basic model of the cornea 10.

[0059] S6, the torus amount of the scleral lens 20 curve model is adjusted by the change of sagittal height in each zone to obtain an optimized scleral lens 20 curve model.

[0060] Based on the sagittal measurements of the four regions of the cornea and sclera 10, a highly personalized scleral lens 20 curve model can be obtained, ensuring that the scleral lens 20 can adapt to the vision correction needs of various users. Furthermore, the designed scleral lens 20 has better fit with the cornea and sclera 10, which is beneficial for improving user comfort. Simultaneously, the circumcurvature of the scleral lens 20 curve model is adjusted by modifying the base arc curvature radius to optimize the curve and achieve better correction results. In summary, this solution can adapt to changes in user vision by simply measuring the sagittal depth and creating a model, and then readjusting the base arc curvature radius and circumcurvature based on new data. This provides a highly flexible method that improves fitting efficiency and significantly enhances the effectiveness of vision correction.

[0061] In this embodiment, S2 specifically includes:

[0062] S21, an OCT device is used to visually scan the cornea and sclera 10 in the horizontal meridian direction to generate a first model of the cornea and sclera 10.

[0063] S22, an OCT device is used to visually scan the cornea and sclera 10 in a steep meridian direction to generate a second model of the cornea and sclera 10.

[0064] S23, using the combination of the first model and the second model, a basic model of the cornea and sclera 10 is established. Combining the obtained first and second models, a more comprehensive and accurate basic model of the cornea and sclera is established. This model can reflect the complete morphology of the cornea and sclera from two main three-dimensional directions, thus making subsequent optimization and design more precise and accurate.

[0065] In this embodiment, S3 specifically includes:

[0066] S31, Select the highest point of the basic model of the cornea and sclera 10 as the reference point, and establish a vertical line on the basic model with the reference point; the vertical line is used to establish the correspondence between the cornea and sclera and the scleral lens.

[0067] S32, the tear gap thickness between the cornea / sclera 10 and the scleral lens 20 located in the vertical direction is determined as k; where k is a constant value. This ensures an appropriate gap between the cornea / sclera and the scleral lens to accommodate the presence of tears. Preferably, k is 0.3 mm.

[0068] S33, read the height H1 of the optical area 11 of the first model and the second model along the vertical line to the reference point, respectively, and the first sag = (first model H1) / 2 + (second model H1) / 2 + k;

[0069] S34, respectively read the height of PCZ of the first model and the second model from the reference point along the vertical line direction as H2, and the second sag = (H2-H1) / 2 of the first model + (H2-H1) / 2 of the second model;

[0070] S35, respectively read the height of the LCZ of the first model and the second model from the reference point along the vertical line direction as H3, the third sag = (H3-H2) / 2 of the first model + (H3-H2) / 2 of the second model;

[0071] S36, read the height H4 of the SLZ of the first model and the second model along the vertical line to the reference point, and the fourth sag = (H4-H3) / 2 of the first model + (H4-H3) / 2 of the second model.

[0072] In summary, subsequent steps S33 to S36 involve reading the sagitta of each region from the basic model and then obtaining four sagittas (first sagitta, second sagitta, third sagitta, and fourth sagitta) through corresponding mathematical calculations. These four sagittas represent the specific characteristics of their respective regions (optical zone 11, PCZ, LCZ, and SLZ) and will be used to construct and optimize the curve model of the scleral lens. This ensures the accuracy and personalization of the model, thereby improving the adaptability and corrective effect of the scleral lens.

[0073] In this embodiment, after S36, the following is also included:

[0074] S37, determine the overall sagitta, the overall sagitta = (first model H4+k+(H4-H3)) / 2+(second model H4+k+(H4-H3)) / 2.

[0075] In this embodiment, S5 specifically includes:

[0076] S51, set the chord lengths of the scleral lens 20 corresponding to the optical zones 11, PCZ, LCZ and SLZ respectively as the first length D1, the second length D2, the third length D3 and the fourth length D4;

[0077] S52, determine the PCZ width, LCZ width and SLZ width of the scleral lens 20 respectively; these width parameters can ensure that each region of the scleral lens 20 is well matched with each region of the cornea and sclera.

[0078] S53, set the first length D1, calculate the second length D2 = D1 + PCZ width * 2; calculate the third length D3 = D1 + PCZ width * 2 + LCZ width * 2; calculate the third length D4 = D1 + PCZ width * 2 + LCZ width * 2 + SLZ width * 2;

[0079] S54, based on the first sag and first length D1, the second sag and second length D2, the third sag and third length D3, and the fourth sag and fourth length D4, the dimensions of the scleral lens 20 corresponding to the four regions of optical zone 11, PCZ, LCZ, and SLZ are designed respectively, generating a combination of scleral lens 20 dimensions. This helps to achieve highly precise and personalized scleral lens design and can achieve good vision correction results.

[0080] In this embodiment, after S54, the following is also included:

[0081] S55, using preset curve rules, the scleral lens 20 size combination is used to plan the scleral lens 20 curve, so as to construct the scleral lens 20 curve model on the basic model of the cornea and sclera 10.

[0082] In this embodiment, the first length D1 is 9 mm, the second length D2 is 11.2 mm, the third length D3 is 12.8 mm, and the fourth length D4 is 14.6 mm.

[0083] In this embodiment, S6 specifically includes:

[0084] S61, the first annular curvature of the cornea corresponding to the optical zone is set as T1, the second annular curvature corresponding to the PCZ is set as T2, the third annular curvature corresponding to the LCZ is set as T3, and the fourth annular curvature corresponding to the SLZ is set as T4; wherein, the annular curvature of each region refers to the degree of curvature of the curve within the corresponding region of the curve.

[0085] S62, calculate T1 = (First Model H1 - Second Model H1) / 2; calculate T2 = (First Model H2 - Second Model H2) / 2 - T1; calculate T3 = (First Model H3 - Second Model H3) / 2 - T1 - T2; calculate T4 = (First Model H4 - Second Model H4) / 2 - T1 - T2 - T3;

[0086] S63, the posterior surface of the rigid scleral lens is designed with a toroidal shape in each zone. The sagitta of each zone in the flat meridian direction is set as the first sagitta, the second sagitta, the third sagitta, and the fourth sagitta; the sagitta of each zone in the steep meridian direction is set as the first sagitta + T1, the second sagitta + T2, the third sagitta + T3, and the fourth sagitta + T4.

[0087] S64, set the circumduction of each zone of the sclera to T, and adjust the circumduction of the sclera to the sclera curve model by adjusting the sag of each zone in the flat meridian direction and the sag of each zone in the steep meridian direction to obtain an optimized sclera to the sclera curve model.

[0088] Specifically, the optimized interval table is as follows:

[0089]

[0090] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for fitting a scleral lens based on the sagittal depth of different regions of the corneosclera, the corneosclera comprising, in order from the middle thereof to the outer side, an optical zone, a PCZ, a LCZ and a SLZ, characterized in that, The fitting method comprises: S1, pre-establishing an optimization interval table of sag and corresponding base arc radius of an optical zone; S2, performing visual scanning on the cornea by using an optical device to generate a basic model of the cornea; S3, measuring a first sag of the corresponding optical zone, a second sag corresponding to the PCZ, a third sag corresponding to the LCZ, and a fourth sag corresponding to the SLZ from the basic model; S4, calling the optimization interval table by using the first sag to obtain a target base arc radius; S5, constructing a scleral lens curve model on the basic model of the cornea based on the target base arc radius, the first sag, the second sag, the third sag, and the fourth sag; specifically: S51, setting the chord length of the scleral lens corresponding to the optical zone, the PCZ, the LCZ, and the SLZ as a first length D1, a second length D2, a third length D3, and a fourth length D4, respectively; S52, determining the PCZ width, the LCZ width, and the SLZ width of the scleral lens, respectively; S53, setting the first length D1, calculating the second length D2=D1+PCZ width*2; calculating the third length D3=D1+PCZ width*2+LCZ width*2; and calculating the third length D4=D1+PCZ width*2+LCZ width*2+SLZ width*2; S54, performing size design on the four regions of the scleral lens corresponding to the optical zone, the PCZ, the LCZ, and the SLZ, respectively, according to the first sag and the first length D1, the second sag and the second length D2, the third sag and the third length D3, and the fourth sag and the fourth length D4, to generate a scleral lens size combination; S55, performing scleral lens curve planning on the scleral lens size combination by using a preset curve rule to construct a scleral lens curve model on the basic model of the cornea; S6, adjusting the toricity of the scleral lens curve model by using the sag change of each region to obtain an optimized scleral lens curve model; specifically: S61, setting the first toricity of the cornea corresponding to the optical zone as T1, the second toricity corresponding to the PCZ as T2, the third toricity corresponding to the LCZ as T3, and the fourth toricity corresponding to the SLZ as T4; S62, calculating T1=(first model H1-second model H1) / 2; calculating T2=(first model H2-second model H2) / 2-T1; calculating T3=(first model H3-second model H3) / 2-T1-T2; and calculating T4=(first model H4-second model H4) / 2-T1-T2-T3; S63, rigidly designing each region of the posterior surface of the scleral lens as toric, setting the sag of each region in the flat meridian direction as the first sag, the second sag, the third sag, and the fourth sag, respectively; and setting the sag of each region in the steep meridian direction as the first sag+T1, the second sag+T2, the third sag+T3, and the fourth sag+T4, respectively. S64, setting the toricity of each zone of the scleral lens as T, adjusting the toricity of the scleral lens curve model through the sagittal height of each zone in the horizontal meridian direction and the sagittal height of each zone in the steep meridian direction to obtain an optimized scleral lens curve model.

2. The method of fitting a scleral lens based on the different regions of the corneo-scleral depth of the eye as claimed in claim 1, wherein, The S2 specifically comprises: S21, using an OCT device to visually scan the angle of the sclera in the horizontal meridian direction to generate a first model of the angle of the sclera; S22, using an OCT device to visually scan the angle of the sclera in the steep meridian direction to generate a second model of the angle of the sclera; S23, establishing a basic model of the angle of the sclera by combining the first model and the second model.

3. The method of fitting a scleral lens based on the different regions of the corneo-scleral depth of the eye as claimed in claim 2, wherein, The S3 specifically comprises: S31, selecting the highest point of the basic model of the angle of the sclera as a reference point, and establishing a vertical line in the basic model with the reference point; S32, determining the tear gap thickness between the angle of the sclera and the scleral lens in the direction of the vertical line as k; wherein k is a constant value; S33, reading the height of the optical zone of the first model and the second model to the reference point in the direction of the vertical line as H1, and the first sagittal height = (first model H1) / 2 + (second model H1) / 2 + k; S34, reading the height of the PCZ of the first model and the second model to the reference point in the direction of the vertical line as H2, and the second sagittal height = (first model H2-H1) / 2 + (second model H2-H1) / 2; S35, reading the height of the LCZ of the first model and the second model to the reference point in the direction of the vertical line as H3, and the third sagittal height = (first model H3-H2) / 2 + (second model H3-H2) / 2; S36, reading the height of the SLZ of the first model and the second model to the reference point in the direction of the vertical line as H4, and the fourth sagittal height = (first model H4-H3) / 2 + (second model H4-H3) / 2.

4. The method of fitting a scleral lens based on the different regions of the corneo-scleral depth of the eye as claimed in claim 3, wherein, The k is 0.3mm.

5. The method of fitting a scleral lens based on the different regions of the corneo-scleral depth of the eye as claimed in claim 3, wherein, The S36 further comprises: S37, determining the total sagittal height, the total sagittal height = (first model H4+k+(H4-H3)) / 2 + (second model H4+k+(H4-H3)) / 2.

6. The method of fitting a scleral lens based on the different regions of the corneo-scleral depth of the eye as claimed in claim 1, wherein, The first length D1 is 9mm, the second length D2 is 11.2mm, the third length D3 is 12.8mm, and the fourth length D4 is 14.6mm.

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