Four-axis asymmetric orthokeratology lens and preparation method

Abstract

The present invention provides a four-axis asymmetric orthokeratology lens and a preparation method, wherein the four-axis asymmetric orthokeratology lens includes a base curve area, and a reverse curve area, an adaptation curve area, and a peripheral curve area formed sequentially outward from the periphery of the base curve area; the center of the base curve area corresponds to the center of the cornea, and the area corresponding to the cornea and the adaptation curve area is a specific annular area. The four-axis asymmetric orthokeratology lens determines the four meridians of the lens body based on the average sagittal value within the specific annular area on the cornea. The four meridians divide the adaptation curve area of ​​the lens body into four sector annular areas, and a different curvature is set on each meridian. Then, the curved surfaces of the four sector annular areas are relatively independently designed with curvature, so that the orthokeratology lens can better fit the wearer's cornea and achieve better adaptability, which is conducive to accurate personalized fitting of various asymmetric and irregular corneas.

Description

Technical Field

[0001] The present invention relates to the technical field of orthokeratology lenses, and in particular to a four-axis asymmetric orthokeratology lens and a preparation method thereof. Background Art

[0002] Orthokeratology lenses are rigid, gas-permeable lenses used in orthokeratology. They generally consist of four arc zones: base arc, reversal arc, adaptation arc, and peripheral arc. The adaptation arc ensures optimal positioning of the lens in the center of the cornea, thereby achieving the desired reshaping effect. However, the adaptation arc zones of existing lenses are mostly rotationally symmetrical spherical or geometrically symmetrical toric geometries, which do not adapt well to the asymmetric and irregular anterior corneal surface. This can lead to lens misalignment and pose a safety hazard.

[0003] The existing Chinese invention patent publication number is CN114740635A, which discloses a four-quadrant asymmetric orthokeratology lens, which adopts a four-quadrant asymmetric design in the adaptation arc area, but the area of ​​the cornea covered in the four quadrants of the orthokeratology lens is the same, and the four meridians dividing the four quadrants are perpendicular to each other, resulting in the inner surface of the orthokeratology lens at the transition of the four quadrants not being well fitted to the anterior surface of the cornea. In addition, the existing Chinese invention patent publication number is CN117192806A, which discloses a special-shaped four-quadrant asymmetric orthokeratology lens, which adopts a special-shaped four-quadrant asymmetric design in the adaptation arc area, but the division of its meridians is fixed and not divided according to the actual corneal morphology, which also easily leads to the inner surface of the orthokeratology lens at the transition between meridians not being well fitted to the anterior surface of the cornea. It can be seen that the above-mentioned existing orthokeratology lenses all have the problem of poor myopia prevention and control effect due to lens deviation, and cannot achieve effective myopia prevention and control effect.

[0004] Therefore, in order to solve the above problems, the present invention proposes a four-axis asymmetric corneal reshaping lens that better fits the wearer's cornea and a preparation method. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a four-axis asymmetric corneal refractive therapy lens and a preparation method.

[0006] According to one object of the present invention, the present invention provides a four-axis asymmetric orthokeratology lens, comprising:

[0007] A base arc region, and a reversal arc region, an adaptation arc region and a peripheral arc region sequentially formed outward from the periphery of the base arc region;

[0008] The orthokeratology lens is provided with a plurality of meridians. Each meridian portion of the inner surface of the adaptation arc area has an average sagittal value between the meridian portion and the horizontal plane of the inner surface vertex of the orthokeratology lens. Among all the meridians on the orthokeratology lens, the meridian with the smallest average sagittal value is the flattest meridian, the meridian with the largest average sagittal value is the steepest meridian, the meridian with the smallest average sagittal value among all the meridians whose included angles with the flattest meridian are not less than 90° is the secondary flattest meridian, and the meridian with the largest average sagittal value among all the meridians whose included angles with the steepest meridian are not less than 90° is the secondary steepest meridian. The adaptation arc area is divided into four sector ring areas by the flattest meridian, the secondary flattest meridian, the steepest meridian, and the secondary steepest meridian.

[0009] The center of the base curve area corresponds to the center of the cornea, and the area on the cornea corresponding to the adaptation curve area is defined as a specific annular zone area;

[0010] The curvature distribution of the inner surface of the flattest meridian of the orthokeratology lens within the adaptation arc area is consistent with the curvature distribution of the outer surface of the flattest meridian of the cornea within the specific annular zone area;

[0011] The curvature distribution of the inner surface of the sub-flat meridian of the orthokeratology lens within the adaptation arc area is consistent with the curvature distribution of the outer surface of the sub-flat meridian of the cornea within the specific annular zone area;

[0012] The curvature distribution of the inner surface of the steepest meridian of the orthokeratology lens within the adaptation arc area is consistent with the curvature distribution of the outer surface of the steepest meridian of the cornea within the specific annular zone area;

[0013] The curvature distribution of the inner surface of the sub-steep meridian of the orthokeratology lens within the adaptation arc area is consistent with the curvature distribution of the outer surface of the sub-steep meridian of the cornea within the specific annular zone area.

[0014] Preferably, adjacent sector ring areas are connected by a gradual transition, and the curvature of each sector ring area transitions gradually between the edges of the two meridians dividing the sector ring area.

[0015] Preferably, on the orthokeratology lens, when the difference in the average sagittal height values ​​between adjacent meridians is greater than 45um, a partition meridian of the orthokeratology lens is set between the adjacent meridians, and the partition meridian of the orthokeratology lens divides the sector ring area formed by the adjacent meridians into two sub-sector ring areas. The curvature distribution of the inner surface of the partition meridian of the orthokeratology lens within the adaptation arc area is consistent with the curvature distribution of the inner corneal anterior surface of the partition meridian of the cornea within the specific annular area.

[0016] Preferably, the partition meridian of the orthokeratology lens is a meridian having an average sagittal height value that is an intermediate value among all meridians within the sector ring area in which it is located.

[0017] Preferably, the two sub-sector ring areas in the sector ring area are connected in a gradual transition, and the inner surfaces of the two sub-sector ring areas form a smooth curved surface.

[0018] Preferably, the curvature of the sector ring area gradually transitions from the edge where the two meridians dividing the sector ring area are located toward the edge where the partition meridian within the sector ring area is located.

[0019] The present invention also provides a method for preparing a four-axis asymmetric orthokeratology lens, comprising the following steps:

[0020] S10. Provide a mirror body to be adjusted, the mirror body including a base arc region, and a reverse arc region, an adaptation arc region, and a peripheral arc region formed sequentially outward from the periphery of the base arc region;

[0021] S20. Divide the adaptation arc into four sectors using the most mean meridian, the second most mean meridian, the steepest meridian, and the second most steep meridian. All meridians pass through the center of the base arc. The most mean meridian, the second most mean meridian, the steepest meridian, and the second most steep meridian are determined as follows:

[0022] S21. Obtain several meridians of the cornea;

[0023] S22. The center of the base curve area of ​​the lens to be adjusted corresponds to the center of the cornea, and the area corresponding to the specific annular area on the cornea is selected as the adaptation curve area of ​​the lens to be adjusted;

[0024] S23. Calculate the average sagittal height from the anterior corneal surface to the horizontal plane of the corneal vertex for each meridian on the cornea within a specific annular zone;

[0025] S24. Obtain the flattest meridian and the steepest meridian of the cornea. Among all the meridians of the cornea, the flattest meridian of the cornea is the meridian with the smallest average sagittal value, and the steepest meridian of the cornea is the meridian with the largest average sagittal value;

[0026] S25. Obtain the corneal sub-horizontal meridian and the corneal sub-steep meridian, wherein the corneal sub-horizontal meridian is the meridian with the smallest average sagittal value among the meridians that form an angle of not less than 90° with the corneal flattest meridian, and the corneal sub-steep meridian is the meridian with the largest average sagittal value among the meridians that form an angle of not less than 90° with the corneal steepest meridian;

[0027] S30. According to the curvature distribution of the cornea's anterior surface of the flattest meridian, the cornea's sub-flattest meridian, the cornea's steepest meridian and the cornea's sub-steepest meridian within the specific annular zone, the curvature distribution of the inner surface of the flattest meridian, the sub-flattest meridian, the steepest meridian and the sub-steepest meridian of the cornea within the adaptation arc zone of the lens to be adjusted is correspondingly adjusted to obtain the orthokeratology lens, so that the curvature distribution of the inner surface of the flattest meridian of the cornea within the adaptation arc zone is consistent with the curvature distribution of the outer surface of the flattest meridian of the cornea within the specific annular zone. The curvature distribution of the inner surface of the sub-flat meridian of the orthokeratology lens within the fitting arc zone is consistent with the curvature distribution of the outer surface of the sub-flat meridian of the cornea within the specific annular zone; the curvature distribution of the inner surface of the steepest meridian of the orthokeratology lens within the fitting arc zone is consistent with the curvature distribution of the outer surface of the steepest meridian of the cornea within the specific annular zone; the curvature distribution of the inner surface of the sub-steep meridian of the orthokeratology lens within the fitting arc zone is consistent with the curvature distribution of the outer surface of the sub-steep meridian of the cornea within the specific annular zone; wherein the adjacent sector ring zones are gradually transitioned.

[0028] Preferably, the method for preparing the four-axis asymmetric orthokeratology lens further comprises:

[0029] S40. Obtaining a corneal partition meridian, wherein the corneal partition meridian is a meridian set between adjacent meridians on the cornea when the difference in average sagittal height between adjacent meridians is greater than 45 μm, and the corneal partition meridian divides the sector ring area formed by the adjacent meridians into two sub-sector ring areas;

[0030] S41. According to the curvature distribution of the anterior surface of the cornea of ​​the partition meridian of the cornea within the specific annular zone area, the partition meridian of the lens body to be adjusted is adjusted accordingly to obtain the orthokeratology lens, so that the curvature distribution of the inner surface of the partition meridian of the orthokeratology lens within the adaptation arc area is consistent with the curvature distribution of the outer surface of the cornea of ​​the partition meridian of the cornea within the specific annular zone area, wherein the adjacent sub-sector annular zones are gradually transitioned.

[0031] Preferably, the partition meridian of the orthokeratology lens is a meridian whose average sagittal height value is an intermediate value among the meridians between two adjacent meridians.

[0032] Preferably, the base arc area, the reversal arc area, the adaptation arc area and the peripheral arc area are integrally formed from the inside to the outside.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. This four-axis asymmetric orthokeratology lens determines the four meridians of the lens body based on the average sagittal height value within a specific annular zone on the cornea. The flattest meridian corresponds to the flattest area of ​​the cornea, the second flattest meridian corresponds to the second flattest area of ​​the cornea, the steepest meridian corresponds to the steepest area of ​​the cornea, and the second steepest meridian corresponds to the second steepest area of ​​the cornea. The four meridians divide the lens body's adaptation arc into four sectors, and a different curvature is set on each meridian. The curved surfaces of the four sectors are then independently designed, allowing the orthokeratology lens to fit the wearer's cornea more closely, achieving better adaptability and facilitating precise and personalized fitting for various asymmetric and irregular corneas.

[0035] 2. By setting partition meridians for the sector ring area with a large span of average sagittal value, the sector ring area with a large span of average sagittal value can be subdivided into two sub-sector ring areas. Since the partition meridian is determined by the median value of the average sagittal value of all meridians in the sector ring area where it is located, it can adapt to the patient's corneal topography more accurately, so that each sector ring area of ​​the lens body adaptation arc zone fits the patient's cornea more closely, further improving the adaptability to the cornea, effectively preventing the lens body from deviating, and optimizing the shaping effect on the cornea.

[0036] The present invention is further described below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a schematic diagram of the overall structure of the four-axis asymmetric corneal refractive therapy lens of the present invention at one viewing angle.

[0038] Figure 2 Schematic diagram of the cross-sectional structure of the four-axis asymmetric orthokeratology lens of the present invention from another viewing angle;

[0039] Figure 3 Schematic diagram of the flattest meridian, steepest meridian, sub-flattest meridian and sub-steepest meridian of the four-axis asymmetric orthokeratology lens of the present invention;

[0040] Figure 4 Schematic diagram for calculating the sagittal height value of one meridian of the four-axis asymmetric orthokeratology lens of the present invention

[0041] In the figure: 1. Base arc area; 2. Reversal arc area; 3. Adaptation arc area; 31. First sector ring area; 32. Second sector ring area; 33. Third sector ring area; 34. Fourth sector ring area; 35. Partition meridian I; 36. Partition meridian II; 37. Partition meridian III; 38. Partition meridian IV; 4. Peripheral arc area; 5. Center of base arc area; 6. Flattest meridian; 7. Steepest meridian; 8. Second flattest meridian; 9. Second steepest meridian. DETAILED DESCRIPTION

[0042] The following description is intended to fully illustrate the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are intended to be exemplary only, and those skilled in the art will readily appreciate other obvious variations. The basic principles of the present invention defined in the following description may be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0043] See also Figure 1-2 The present invention provides a technical solution: a four-axis asymmetric orthokeratology lens, comprising:

[0044] The lens body is in the shape of a circular arc sheet, and includes a base arc zone 1, a reversal arc zone 2, an adaptation arc zone 3 and a peripheral arc zone 4. The base arc zone 1, the reversal arc zone 2, the adaptation arc zone 3 and the peripheral arc zone 4 are integrated from the inside out. The base arc zone 1 is an arc sheet structure located in the central area of ​​the lens body, the reversal arc zone 2 surrounds the base arc zone 1 in a narrower ring structure, the adaptation arc zone 3 surrounds the reversal arc zone 2 in a slightly wider ring structure, and the peripheral arc zone 4 surrounds the adaptation arc zone 3 in a narrower ring structure. The base arc zone 1 serves as the central optical zone and treatment area, and is mainly used to flatten the corneal surface. The reversal arc zone 2 causes the central tear fluid to gather, prompting the base arc zone 1 of the lens to flatten the central anterior surface of the cornea. The adaptation arc zone 3 fits the cornea, fixes the lens, and increases the stability of lens wearing. The peripheral arc zone 4 is slightly raised at the edge to facilitate smooth tear exchange.

[0045] That is, the four-axis asymmetric corneal reshaping lens includes: a base curve area 1, and a reversal curve area 2, an adaptation curve area 3 and a peripheral curve area 4 that are formed successively from the periphery of the base curve area 1 outward.

[0046] When in use, the center of the base curve area 1 corresponds to the center of the cornea, and the area corresponding to the cornea and the adaptation arc area 3 is defined as a specific annular zone; the relevant data of multiple meridians of the cornea are obtained, and the multiple meridians of the cornea can divide the cornea into multiple equal sector-shaped areas. In the specific annular zone, there is an average sagittal value between the front surface of the cornea and the horizontal plane of the corneal vertex. Among all the meridians on the cornea, the meridian with the smallest average sagittal value is the flattest meridian of the cornea, and the average sagittal value is the smallest. The meridian with the largest height value is the steepest meridian of the cornea, the meridian with an angle of not less than 90° with the flattest meridian and the smallest average sagittal value is the sub-flat meridian of the cornea, and the meridian with an angle of not less than 90° with the steepest meridian and the largest average sagittal value is the sub-steepest meridian of the cornea. The specific annular zone is divided into four corneal sector zones by the flattest meridian of the cornea, the sub-flat meridian of the cornea, the steepest meridian of the cornea, and the sub-steepest meridian of the cornea;

[0047] Similarly, the orthokeratology lens is provided with a plurality of meridians, and each meridian portion of the inner surface of the adaptation arc zone 3 has an average sagittal value between the horizontal plane of the vertex of the inner surface of the orthokeratology lens and the inner surface of the orthokeratology lens. Among all the meridians on the orthokeratology lens, the meridian with the smallest average sagittal value is the flattest meridian 6 of the orthokeratology lens, and the meridian with the largest average sagittal value is the steepest meridian 7 of the orthokeratology lens. The angles between all meridians and the flattest meridian 6 of the orthokeratology lens are not less than 90 degrees. The meridian with the smallest average sagittal value among the meridians with an angle of not less than 90° with the steepest meridian 7 of the orthokeratology lens is the sub-flat meridian 8 of the orthokeratology lens; the meridian with the largest average sagittal value among all the meridians with an angle of not less than 90° with the steepest meridian 7 of the orthokeratology lens is the sub-steepest meridian 9 of the orthokeratology lens; the adaptation arc area 3 is divided into four sector ring areas by the flattest meridian 6 of the orthokeratology lens, the sub-flat meridian 8 of the orthokeratology lens, the steepest meridian 7 of the orthokeratology lens, and the sub-steepest meridian 9 of the orthokeratology lens;

[0048] The curvature distribution of the inner surface of the flattest meridian 6 of the orthokeratology lens within the adaptation arc area is consistent with the curvature distribution of the outer surface of the flattest meridian of the cornea within the specific annular zone area;

[0049] The curvature distribution of the inner surface of the sub-flat meridian 8 of the orthokeratology lens within the adaptation arc area is consistent with the curvature distribution of the outer surface of the sub-flat meridian of the cornea within the specific annular zone area;

[0050] The curvature distribution of the inner surface of the steepest meridian 7 of the orthokeratology lens within the adaptation arc area is consistent with the curvature distribution of the outer surface of the steepest meridian of the cornea within the specific annular zone area;

[0051] The curvature distribution of the inner surface of the sub-steep meridian 9 of the orthokeratology lens within the adaptation arc area is consistent with the curvature distribution of the outer surface of the sub-steep meridian of the cornea within the specific annular zone area.

[0052] Preferably, on the orthokeratology lens, adjacent sector ring areas are connected by a gradual transition, wherein the inner surfaces of adjacent sector ring areas form a smooth curved surface.

[0053] For details, see Figure 1On the orthokeratology lens, the four sector ring areas are the first sector ring area 31, the second sector ring area 32, the third sector ring area 33 and the fourth sector ring area 34, wherein the first sector ring area 31 and the second sector ring area 32 are divided by the steepest meridian 7 of the orthokeratology lens, and the first sector ring area 31 and the second sector ring area 32 are gradually transitioned and connected, and the inner surfaces of the first sector ring area 31 and the second sector ring area 32 form a smooth curved surface; the second sector ring area 32 and the third sector ring area 33 are divided by the sub-flat meridian 8 of the orthokeratology lens, and the second sector ring area 32 and the third sector ring area 33 are gradually transitioned and connected, The inner surfaces of the second sector ring area 32 and the third sector ring area 33 form a smooth curved surface; the third sector ring area 33 and the fourth sector ring area 34 are divided by the sub-steep meridian 9 of the orthokeratology lens, and the third sector ring area 33 and the fourth sector ring area 34 are gradually transitioned to be connected, and the inner surfaces of the third sector ring area 33 and the fourth sector ring area 34 form a smooth curved surface; the fourth sector ring area 34 and the first sector ring area 31 are divided by the flattest meridian 6 of the orthokeratology lens, and the fourth sector ring area 34 and the first sector ring area 31 are gradually transitioned to be connected, and the inner surfaces of the fourth sector ring area 34 and the first sector ring area 31 form a smooth curved surface.

[0054] See also Figure 3 The radial edges of the inner surface of the adaptation arc zone 3 are arc zone edge c and arc zone edge d respectively, the flattest meridian 6 and arc zone edge c intersect to form intersection a, the flattest meridian 6 and arc zone edge d intersect to form intersection b, in the flattest meridian 6 on the inner surface of the mirror body, intersection a and intersection b and all points therebetween form a set, which is called arc segment ab, and the set is the flattest meridian 6 portion of the inner surface of the adaptation arc zone 3. Those skilled in the art can determine by analogy the sub-flat meridian 8 portion of the inner surface of the adaptation arc zone 3, the steepest meridian 7 portion of the inner surface of the adaptation arc zone 3, and the sub-steep meridian 9 portion of the inner surface of the adaptation arc zone 3 mentioned in the above scheme, as well as the flattest meridian portion of the front surface of the specific annular area, the sub-flat meridian portion of the front surface of the specific annular area, the steepest meridian portion of the front surface of the specific annular area, and the sub-steep meridian portion of the front surface of the specific annular area.

[0055] The arc zone edges are the edges on both sides of the inner surface of the adaptation arc zone 3, and the flattest meridian 6 portion of the inner surface of the adaptation arc zone 3 is a line segment obtained by intercepting the flattest meridian 6 of the inner surface of the orthokeratology lens by the two arc zone edges. In other words, the flattest meridian 6 portion of the inner surface of the adaptation arc zone 3 has its ends in the length direction respectively located on one of the arc zone edges.

[0056] It should also be noted that the meridian of the cornea is a meridian on the cornea, which passes through the center of the cornea and has both ends reaching the edge of the cornea. The meridian of the orthokeratology lens is the meridian on the orthokeratology lens corresponding to the meridian of the cornea when the orthokeratology lens is placed on the anterior surface of the cornea. The sagittal value is a commonly used concept in geometry. In orthokeratology lenses and corneas, the sagittal value can help understand the design features of the lens body, such as the thickness distribution and curvature of the lens body. The sagittal value refers to the vertical distance from the reference plane to a certain point on the lens body or corneal surface. Regarding the calculation of the average sagittal value on the cornea and the lens body, specifically, each meridian on the cornea is on the anterior surface of a specific annular area. There are multiple measurement points. The vertical distances between each measurement point and the horizontal plane where the vertex of the anterior corneal surface is located are added together, and then divided by the number of measurement points. The result is the average sagittal height value of each meridian on the cornea on the anterior surface of a specific annular zone area. Each meridian on the lens body has multiple measurement points on the inner surface of the adaptation arc zone 3. The vertical distances between each measurement point and the horizontal plane where the vertex of the inner surface of the lens body is located are added together, and then divided by the number of measurement points. The result is the average sagittal height value of each meridian on the lens body on the inner surface of the adaptation arc zone 3. For orthokeratology lenses, an optical microscope or interferometer can be used to obtain the distance from the lens body surface to the specified reference plane.

[0057] In one embodiment of the present invention, see Figure 4 A meridian x is set on the mirror body, and a vertex horizontal plane y is set on the mirror body. Five measuring points are set on the inner surface of the adaptation arc area 3 of the meridian x: N1, N2, N3, N4, and N5. The vertical distances from N1, N2, N3, N4, and N5 to the vertex horizontal plane y of the mirror body are measured and added, and then divided by the number of measuring points 5. The result is the average sagittal value of the meridian x on the inner surface of the adaptation arc area 3 on the mirror body.

[0058] The four-axis asymmetric orthokeratology lens determines the four meridians of the lens body according to the average sagittal height value in a specific annular zone on the cornea, wherein the flattest meridian 6 of the orthokeratology lens corresponds to the flattest area of ​​the cornea, the second flattest meridian 8 of the orthokeratology lens corresponds to the second flattest area of ​​the cornea, the steepest meridian 7 of the orthokeratology lens corresponds to the steepest area of ​​the cornea, and the second steepest meridian 9 of the orthokeratology lens corresponds to the second steepest area of ​​the cornea. The four meridians of the orthokeratology lens divide the adaptation arc area 3 of the lens body into four sector ring areas, and set different curvatures on each meridian in a targeted manner, and then perform relatively independent curvature design on the curved surfaces of the four sector ring areas, so that the orthokeratology lens can fit the wearer's cornea more closely and achieve better adaptability, which is conducive to accurate personalized fitting of various asymmetric and irregular corneas.

[0059] Preferably, the base arc area 1, the inversion arc area 2, the adaptation arc area 3 and the peripheral arc area 4 are integrally formed from the inside to the outside.

[0060] It should be noted that in this scheme, the center of the cornea corresponds to the center 5 of the base curve area. Therefore, the flattest meridian 6 of the orthokeratology lens, the second flattest meridian 8 of the orthokeratology lens, the steepest meridian 7 of the orthokeratology lens and the second steepest meridian 9 of the orthokeratology lens all pass through the center of the base curve area 1.

[0061] Preferably, on the orthokeratology lens, the curvature of each sector ring area transitions gradually between the edges of the two meridians dividing the sector ring area.

[0062] In one embodiment of the present invention, the curvature of the first sector ring area 31 increases uniformly from the edge where the flattest meridian 6 of the orthokeratology lens is located to the edge where the steepest meridian 7 of the orthokeratology lens is located;

[0063] The curvature of the second sector ring area 32 decreases evenly from the edge where the steepest meridian 7 of the orthokeratology lens is located to the edge where the sub-flat meridian 8 of the orthokeratology lens is located;

[0064] The curvature of the third sector ring area 33 increases evenly from the edge where the sub-flat meridian 8 of the orthokeratology lens is located to the edge where the sub-steep meridian 9 of the orthokeratology lens is located;

[0065] The curvature of the fourth sector ring area 34 decreases evenly from the edge where the sub-steep meridian 9 of the orthokeratology lens is located to the edge where the flattest meridian 6 of the orthokeratology lens is located.

[0066] In order to further improve the adaptability to the cornea, effectively prevent the lens body from being displaced, and optimize the shaping effect on the cornea, on the orthokeratology lens, when the difference in the average sagittal height value between adjacent meridians is greater than 45um, a partition meridian of the orthokeratology lens is set between adjacent meridians. The partition meridian of the orthokeratology lens divides the sector ring area formed by the adjacent meridians into two sub-sector ring areas. The curvature distribution of the inner surface of the partition meridian of the orthokeratology lens within the adaptation arc area 3 is consistent with the curvature distribution of the inner corneal anterior surface of the partition meridian of the cornea within the specific annular area.

[0067] Specifically, when the average sagittal difference between the flattest meridian of the cornea and the steepest meridian of the cornea is greater than 45um, a partition meridian I of the cornea is virtually set between the flattest meridian of the cornea and the steepest meridian of the cornea; if the average sagittal difference between the steepest meridian of the cornea and the sub-flat meridian of the cornea is greater than 45um, a partition meridian II of the cornea is virtually set between the steepest meridian of the cornea and the sub-flat meridian of the orthokeratology lens; if the average sagittal difference between the sub-flat meridian of the cornea and the sub-steep meridian of the cornea is greater than 45um, a partition meridian III of the cornea is virtually set between the sub-flat meridian of the cornea and the sub-steep meridian of the cornea; if the average sagittal difference between the sub-steep meridian of the cornea and the flattest meridian of the cornea is greater than 45um, a partition meridian IV of the cornea is virtually set between the sub-steep meridian of the cornea and the flattest meridian of the cornea.

[0068] Correspondingly, when the average sagittal difference between the flattest meridian 6 of the orthokeratology lens and the steepest meridian 7 of the orthokeratology lens is greater than 45 μm, a partition meridian I 35 of the orthokeratology lens is set between the flattest meridian 6 of the orthokeratology lens and the steepest meridian 7 of the orthokeratology lens. The partition meridian I 35 of the orthokeratology lens divides the first sector ring area 31 into two sub-sector ring areas, and the two sub-sector ring areas are gradually transitioned and connected. Otherwise, no partition of the orthokeratology lens is set. Meridian I 35; if the average sagittal difference between the steepest meridian 7 of the orthokeratology lens and the sub-flat meridian 8 of the orthokeratology lens is greater than 45 μm, a partition meridian II 36 of the orthokeratology lens is set between the steepest meridian 7 of the orthokeratology lens and the sub-flat meridian 8 of the orthokeratology lens. The partition meridian II 36 of the orthokeratology lens divides the second sector ring area 32 into two sub-sector ring areas, and the two sub-sector ring areas are gradually transitioned and connected. Otherwise, the partition meridian of the orthokeratology lens is not set. Line II 36; if the average sagittal difference between the sub-flat meridian 8 of the orthokeratology lens and the sub-steep meridian 9 of the orthokeratology lens is greater than 45 μm, a partition meridian III 37 of the orthokeratology lens is set between the sub-flat meridian 8 of the orthokeratology lens and the sub-steep meridian 9 of the orthokeratology lens. The partition meridian III 37 of the orthokeratology lens divides the third sector ring area 33 into two sub-sector ring areas, and the two sub-sector ring areas are gradually transitioned and connected. Otherwise, the partition meridian III of the orthokeratology lens is not set. 37; If the average sagittal height difference between the sub-steep meridian 9 of the orthokeratology lens and the flattest meridian 6 of the orthokeratology lens is greater than 45um, a partition meridian IV 38 of the orthokeratology lens is set between the sub-steep meridian 9 of the orthokeratology lens and the flattest meridian 6 of the orthokeratology lens. The partition meridian IV 38 of the orthokeratology lens divides the fourth sector ring area 34 into two sub-sector ring areas, and the two sub-sector ring areas are gradually transitioned and connected. Otherwise, the partition meridian IV 38 of the orthokeratology lens is not set.

[0069] The curvature distribution of the inner surface of the partition meridian I35 of the orthokeratology lens within the adaptation arc zone 3 is consistent with the curvature distribution of the inner corneal anterior surface of the partition meridian I of the cornea within the specific annular zone area;

[0070] The curvature distribution of the inner surface of the partition meridian II 36 of the orthokeratology lens within the adaptation arc zone 3 is consistent with the curvature distribution of the inner corneal anterior surface of the partition meridian II of the cornea within the specific annular zone;

[0071] The curvature distribution of the inner surface of the partition meridian III 37 of the orthokeratology lens within the adaptation arc zone 3 is consistent with the curvature distribution of the inner corneal anterior surface of the partition meridian III of the cornea within the specific annular zone;

[0072] The curvature distribution of the inner surface of the partition meridian IV 38 of the orthokeratology lens within the adaptation arc zone 3 is consistent with the curvature distribution of the inner corneal anterior surface of the partition meridian IV of the cornea within the specific annular zone;

[0073] Preferably, the partition meridian of the orthokeratology lens is a meridian having an average sagittal height value that is an intermediate value among all meridians within the sector ring area in which it is located.

[0074] In one embodiment of the present invention, the partition meridians of the orthokeratology lens include:

[0075] Partition meridian I35: a meridian having an average sagittal value of an intermediate value among all meridians between the flattest meridian 6 and the steepest meridian 7 of the orthokeratology lens on the orthokeratology lens is selected as partition meridian I35 of the orthokeratology lens;

[0076] A partition meridian II 36 is selected, wherein a meridian having an average sagittal value of an intermediate value among all meridians between the steepest meridian 7 of the orthokeratology lens and the second flat meridian 8 of the orthokeratology lens is selected as the partition meridian II 36 of the orthokeratology lens;

[0077] Partition meridian III 37, a meridian with an average sagittal value of the middle value among all meridians between the sub-flat meridian 8 and the sub-steep meridian 9 of the orthokeratology lens on the orthokeratology lens is selected as the partition meridian III 37 of the orthokeratology lens;

[0078] Partition meridian IV38, a meridian with an average sagittal value that is an intermediate value among all meridians between the sub-steepest meridian 9 of the orthokeratology lens and the flattest meridian 6 of the orthokeratology lens is selected as the partition meridian IV38 of the orthokeratology lens.

[0079] Preferably, the two sub-sector ring areas in the sector ring area of ​​the orthokeratology lens are gradually transitioned and connected, and the inner surfaces of the two sub-sector ring areas form a smooth curved surface. In other words, the curvature value of the inner surface of the sub-sector ring area increases or decreases uniformly along the circumference of the adaptation arc area 3.

[0080] Preferably, the curvature of the sector ring area of ​​the orthokeratology lens gradually transitions from the edge where the two meridians dividing the sector ring area are located toward the edge where the partition meridian within the sector ring area is located.

[0081] In one embodiment of the present invention, the curvature value of the inner surface of the first sector ring area 31 first increases uniformly from the edge where the flattest meridian 6 of the orthokeratology lens is located to the edge where the partition meridian I 35 is located, and then increases uniformly from the edge where the partition meridian I 35 is located to the edge where the steepest meridian 7 of the orthokeratology lens is located.

[0082] The curvature value of the inner surface of the second sector ring area 32 first decreases uniformly from the edge where the steepest meridian 7 of the orthokeratology lens is located to the edge where the partition meridian II 36 is located, and then decreases uniformly from the edge where the partition meridian II 36 is located to the edge where the sub-flat meridian 8 of the orthokeratology lens is located;

[0083] The curvature value of the inner surface of the third sector ring area 33 first increases uniformly from the edge where the sub-flat meridian 8 of the orthokeratology lens is located to the edge where the partition meridian III 37 is located, and then increases uniformly from the edge where the partition meridian III 37 is located to the edge where the sub-steep meridian 9 of the orthokeratology lens is located;

[0084] The curvature value of the inner surface of the fourth sector ring area 34 first decreases uniformly from the edge where the sub-steep meridian 9 of the orthokeratology lens is located to the edge where the partition meridian IV 38 is located, and then decreases uniformly from the edge where the partition meridian IV 38 is located to the edge where the flattest meridian 6 of the orthokeratology lens is located.

[0085] More specifically, the closer the inner surface of the first sector ring area 31 is to the flattest meridian 6 of the orthokeratology lens, the smaller the partial curvature value is, that is, the flatter it is; the closer the inner surface of the first sector ring area 31 is to the steepest meridian 7 of the orthokeratology lens, the larger the partial curvature value is, that is, the steeper it is; the curvature value of the inner surface of the second sector ring area 32 first decreases uniformly from the edge where the steepest meridian 7 of the orthokeratology lens is located to the edge where the partition meridian II 36 is located, and then decreases uniformly from the edge where the partition meridian II 36 is located to the edge where the secondary flat meridian 8 of the orthokeratology lens is located; the closer the inner surface of the second sector ring area 32 is to the steepest meridian 7 of the orthokeratology lens, the larger the partial curvature value is, that is, the steeper it is; the closer the inner surface of the second sector ring area 32 is to the secondary flat meridian 8 of the orthokeratology lens, the smaller the partial curvature is, that is, the flatter it is; the curvature value of the inner surface of the third sector ring area 33 first decreases uniformly from the edge where the secondary flat meridian 8 of the orthokeratology lens is located to the partition meridian III 37 The curvature value of the inner surface of the fourth sector ring area 34 first decreases uniformly from the edge of the secondary steep meridian 9 of the orthokeratology lens to the edge of the partition meridian IV 38, and then decreases uniformly from the edge of the partition meridian IV 38 to the edge of the flattest meridian 6 of the orthokeratology lens. The closer the inner surface of the fourth sector ring area 34 is to the flattest meridian 9 of the orthokeratology lens, the larger the partial curvature value is, that is, the steeper it is. The closer the inner surface of the fourth sector ring area 34 is to the flattest meridian 6 of the orthokeratology lens, the smaller the partial curvature value is, that is, the flatter it is.

[0086] Preferably, the curvature distribution of the inner surface of the partition meridian I 35 of the orthokeratology lens, the partition meridian II 36 of the orthokeratology lens, the partition meridian III 37 of the orthokeratology lens and the partition meridian IV 38 of the orthokeratology lens within the adaptation arc zone 3 is consistent with the curvature distribution of the front surface of the partition meridian of the cornea within the specific annular zone area.

[0087] This four-axis asymmetric orthokeratology lens can subdivide the sector ring area with a large average sagittal value span into two sub-sector ring areas by setting a partition meridian for the sector ring area with a large average sagittal value span. Because the partition meridian is determined by taking the median value of the average sagittal value of all meridians within the sector ring area, it can more accurately adapt to the patient's corneal topography, so that each sector ring area of ​​the lens body adaptation arc zone 3 is more closely fitted to the patient's cornea, further improving the adaptability to the cornea, effectively preventing lens body deviation, and optimizing the reshaping effect on the cornea. The above-mentioned sector ring area with a large average sagittal value span refers to the sector ring area where the average sagittal difference between two adjacent meridians is greater than 45μm.

[0088] How to use the four-axis asymmetric orthokeratology lens:

[0089] When wearing it, make the center of the cornea correspond to the center of the base curve area 5, and place the orthokeratology lens directly on the cornea. The front surface of the cornea and the inner surface of the orthokeratology lens are in contact. Because there is tear fluid between the cornea and the orthokeratology lens, and the curvature of each meridian part of the adaptation arc area 3 of the orthokeratology lens is different, the orthokeratology lens will slide on the cornea to a stable state. In this state, the front surface of the cornea and the inner surface of the orthokeratology lens are in contact, the meridian of the cornea and the meridian of the orthokeratology lens are aligned, and the orthokeratology lens applies pressure to the cornea to achieve corneal shaping.

[0090] The present invention also provides a preparation method, and the above-mentioned four-axis asymmetric orthokeratology lens is prepared by the preparation method, which specifically comprises the following steps:

[0091] S10. Provide a mirror body to be adjusted, the mirror body comprising a base arc region 1, and a reverse arc region 2, an adaptation arc region 3, and a peripheral arc region 4 formed sequentially outward from the periphery of the base arc region 1;

[0092] S20. Divide the adaptation arc region 3 into four sectors by the most mean meridian 6, the second most mean meridian 8, the steepest meridian 7, and the second most steep meridian 9. All meridians pass through the center of the base arc region 1. The steps for determining the most mean meridian 6, the second most mean meridian 8, the steepest meridian 7, and the second most steep meridian 9 are as follows:

[0093] S21. Obtain several meridians of the cornea;

[0094] S22. The center of the base curve area 1 of the lens to be adjusted corresponds to the center of the cornea, and the area corresponding to the specific annular zone on the cornea is selected as the adaptation curve area 3 of the lens to be adjusted;

[0095] S23. Calculate the average sagittal height from the anterior corneal surface to the horizontal plane of the corneal vertex for each meridian on the cornea within a specific annular zone;

[0096] S24. Obtain the flattest meridian and the steepest meridian of the cornea. Among all the meridians of the cornea, the flattest meridian of the cornea is the meridian with the smallest average sagittal value, and the steepest meridian of the cornea is the meridian with the largest average sagittal value;

[0097] S25. Obtain the corneal sub-horizontal meridian and the corneal sub-steep meridian, wherein the corneal sub-horizontal meridian is the meridian with the smallest average sagittal value among the meridians that form an angle of not less than 90° with the corneal flattest meridian, and the corneal sub-steep meridian is the meridian with the largest average sagittal value among the meridians that form an angle of not less than 90° with the corneal steepest meridian;

[0098] S30. According to the curvature distribution of the cornea's anterior surface of the flattest meridian, the cornea's sub-flattest meridian, the cornea's steepest meridian and the cornea's sub-steepest meridian within the specific annular zone, the curvature distribution of the inner surface of the flattest meridian 6, the sub-flattest meridian 8, the steepest meridian 7 and the sub-steepest meridian 9 of the lens body to be adjusted within the adaptation arc zone 3 is correspondingly adjusted to obtain the orthokeratology lens, so that the curvature distribution of the inner surface of the flattest meridian of the cornea within the adaptation arc zone is consistent with the curvature distribution of the outer surface of the flattest meridian of the cornea within the specific annular zone. The curvature distribution of the inner surface of the sub-flat meridian of the orthokeratology lens within the adaptation arc zone is consistent with the curvature distribution of the outer surface of the sub-flat meridian of the cornea within the specific annular zone; the curvature distribution of the inner surface of the steepest meridian of the orthokeratology lens within the adaptation arc zone is consistent with the curvature distribution of the outer surface of the steepest meridian of the cornea within the specific annular zone; the curvature distribution of the inner surface of the sub-steep meridian of the orthokeratology lens within the adaptation arc zone is consistent with the curvature distribution of the outer surface of the sub-steep meridian of the cornea within the specific annular zone, wherein adjacent sector ring areas are gradually transitioned.

[0099] The preparation method further comprises:

[0100] S40. Obtaining a corneal partition meridian, wherein the corneal partition meridian is a meridian set between adjacent meridians on the cornea when the difference in average sagittal height between adjacent meridians is greater than 45 μm, and the corneal partition meridian divides the sector ring area formed by the adjacent meridians into two sub-sector ring areas;

[0101] S41. According to the curvature distribution of the anterior surface of the cornea of ​​the partition meridian of the cornea within the specific annular zone area, the partition meridian of the lens body to be adjusted is adjusted accordingly to obtain the orthokeratology lens, so that the curvature distribution of the inner surface of the partition meridian of the orthokeratology lens within the adaptation arc area 3 is consistent with the curvature distribution of the outer surface of the cornea of ​​the partition meridian of the cornea within the specific annular zone area, wherein the adjacent sub-sector annular zones are gradually transitioned.

[0102] Preferably, the partition meridian of the orthokeratology lens is a meridian whose average sagittal height value is an intermediate value among the meridians between two adjacent meridians.

[0103] In summary, the four-axis asymmetric corneal reshaping lens provided by the present invention determines the four meridians of the lens body according to the average sagittal value in a specific annular area on the cornea. The four meridians divide the adaptation arc area 3 of the lens body into four sector ring areas, and set different curvatures on each meridian in a targeted manner, and then perform relatively independent curvature design on the curved surfaces of the four sector ring areas. Further, by setting partition meridians for the sector ring area with a larger span of average sagittal value, the sector ring area with a larger span of average sagittal value can be subdivided into two sub-sector ring areas, which can more accurately adapt to the patient's corneal topography, so that the corneal reshaping lens can fit the wearer's cornea better and achieve better adaptability.

[0104] The embodiments described above are only used to illustrate the technical ideas and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. The scope of the patent application of the present invention cannot be limited by these embodiments alone. That is, any equivalent changes or modifications made according to the spirit disclosed by the present invention still fall within the patent scope of the present invention.

Claims

1. A four-axis asymmetric orthokeratology lens, characterized in that: include: A base arc region (1), and a reversal arc region (2), an adaptation arc region (3) and a peripheral arc region (4) formed sequentially and outwardly from the periphery of the base arc region (1); The orthokeratology lens is provided with a plurality of meridians. Each meridian portion of the inner surface of the adaptation arc zone (3) has an average sagittal value between the meridian portion and the horizontal plane of the inner surface vertex of the orthokeratology lens. Among all the meridians on the orthokeratology lens, the meridian with the smallest average sagittal value is the flattest meridian (6), the meridian with the largest average sagittal value is the steepest meridian (7), the meridian with the smallest average sagittal value among all the meridians whose angles with the flattest meridian (6) are not less than 90° is the secondary flattest meridian (8), and the meridian with the largest average sagittal value among all the meridians whose angles with the steepest meridian (7) are not less than 90° is the secondary steepest meridian (9). The adaptation arc zone (3) is divided into four sector ring zones by the flattest meridian (6), the secondary flattest meridian (8), the steepest meridian (7) and the secondary steepest meridian (9); The center of the base curve area (1) corresponds to the center of the cornea, and the area on the cornea corresponding to the adaptation curve area (3) is defined as a specific annular zone area; The curvature distribution of the inner surface of the flattest meridian of the orthokeratology lens within the adaptation arc area is consistent with the curvature distribution of the outer surface of the flattest meridian of the cornea within the specific annular zone area; The curvature distribution of the inner surface of the sub-flat meridian of the orthokeratology lens within the adaptation arc area is consistent with the curvature distribution of the outer surface of the sub-flat meridian of the cornea within the specific annular zone area; The curvature distribution of the inner surface of the steepest meridian of the orthokeratology lens within the adaptation arc area is consistent with the curvature distribution of the outer surface of the steepest meridian of the cornea within the specific annular zone area; The curvature distribution of the inner surface of the sub-steep meridian of the orthokeratology lens within the adaptation arc area is consistent with the curvature distribution of the outer surface of the sub-steep meridian of the cornea within the specific annular zone area; Adjacent sector ring areas are connected by a gradual transition, and the curvature of each sector ring area gradually transitions between the edges of the two meridians dividing the sector ring area; On the orthokeratology lens, when the difference in average sagittal height between adjacent meridians is greater than 45 μm, a partition meridian of the orthokeratology lens is set between the adjacent meridians, and the partition meridian of the orthokeratology lens divides the sector ring area formed by the adjacent meridians into two sub-sector ring areas, and the curvature distribution of the inner surface of the partition meridian of the orthokeratology lens within the adaptation arc area (3) is consistent with the curvature distribution of the inner corneal anterior surface of the partition meridian of the cornea within the specific annular area; The partition meridian of the orthokeratology lens is a meridian having an average sagittal height value that is the middle value among all meridians within the sector ring area in which it is located.

2. A four-axis asymmetric orthokeratology lens according to claim 1, characterized in that: The two sub-sector ring areas in the sector ring area are connected in a gradual transition, and the inner surfaces of the two sub-sector ring areas form a smooth curved surface.

3. The four-axis asymmetric orthokeratology lens according to claim 1, characterized in that: The curvature of the sector ring area gradually transitions from the edge where the two meridians dividing the sector ring area are located to the edge where the partition meridian within the sector ring area is located.

4. A method for preparing a four-axis asymmetric orthokeratology lens, characterized in that: The following steps are involved: S10. Providing a mirror body to be adjusted, the mirror body comprising a base arc region (1), and a reversal arc region (2), an adaptation arc region (3), and a peripheral arc region (4) formed sequentially outward from the periphery of the base arc region (1); S20. The adaptation arc area (3) is divided into four sector areas by the most flat meridian (6), the second most flat meridian (8), the steepest meridian (7) and the second most steep meridian (9), wherein all meridians pass through the center of the base arc area (1). The steps for determining the most flat meridian (6), the second most flat meridian (8), the steepest meridian (7) and the second most steep meridian (9) are as follows: S21. Obtain several meridians of the cornea; S22. The center of the base curve area (1) of the lens to be adjusted corresponds to the center of the cornea, and the area corresponding to the specific annular area on the cornea is selected as the adaptation curve area (3) of the lens to be adjusted; S23. Calculate the average sagittal height from the anterior corneal surface to the horizontal plane of the corneal vertex for each meridian on the cornea within a specific annular zone; S24. Obtaining the flattest meridian and the steepest meridian of the cornea, wherein, among all the meridians of the cornea, the flattest meridian of the cornea is the meridian with the smallest average sagittal value, and the steepest meridian of the cornea is the meridian with the largest average sagittal value; S25. Obtaining the corneal sub-horizontal meridian and the corneal sub-steep meridian, wherein the corneal sub-horizontal meridian is the meridian with the smallest average sagittal value among the meridians that form an angle of not less than 90° with the corneal flattest meridian, and the corneal sub-steep meridian is the meridian with the largest average sagittal value among the meridians that form an angle of not less than 90° with the corneal steepest meridian; S30. According to the curvature distribution of the cornea's anterior surface of the flattest meridian, the cornea's sub-flattest meridian, the cornea's steepest meridian, and the cornea's sub-steepest meridian within the specific annular zone, the curvature distribution of the inner surface of the flattest meridian (6), the sub-flattest meridian (8), the steepest meridian (7), and the sub-steepest meridian (9) of the lens body to be adjusted within the adaptation arc zone (3) is correspondingly adjusted to obtain the orthokeratology lens, so that the curvature distribution of the inner surface of the flattest meridian of the orthokeratology lens within the adaptation arc zone is consistent with the curvature distribution of the flattest meridian of the cornea within the adaptation arc zone. The curvature distribution of the outer surface within the specific annular zone is consistent; the curvature distribution of the inner surface of the sub-flat meridian of the orthokeratology lens within the adaptation arc zone is consistent with the curvature distribution of the outer surface of the sub-flat meridian of the cornea within the specific annular zone; the curvature distribution of the inner surface of the steepest meridian of the orthokeratology lens within the adaptation arc zone is consistent with the curvature distribution of the outer surface of the steepest meridian of the cornea within the specific annular zone; the curvature distribution of the inner surface of the sub-steep meridian of the orthokeratology lens within the adaptation arc zone is consistent with the curvature distribution of the outer surface of the sub-steep meridian of the cornea within the specific annular zone; The adjacent sector ring areas are gradually transitioned; Also includes: S40. Obtaining a corneal partition meridian, wherein the corneal partition meridian is a meridian set between adjacent meridians on the cornea when the difference in average sagittal height between adjacent meridians is greater than 45 μm, and the corneal partition meridian divides the sector ring area formed by the adjacent meridians into two sub-sector ring areas; S41. According to the curvature distribution of the corneal front surface of the corneal partition meridian within the specific annular zone, the partition meridian of the lens body to be adjusted is correspondingly adjusted to obtain the orthokeratology lens, so that the curvature distribution of the inner surface of the partition meridian of the orthokeratology lens within the adaptation arc zone (3) is consistent with the curvature distribution of the corneal outer surface of the corneal partition meridian within the specific annular zone, wherein a gradual transition process is performed between adjacent sub-sector annular zones; The partition meridian of the orthokeratology lens is a meridian whose average sagittal height value is the middle value among the meridians between two adjacent meridians.

5. The method for preparing a four-axis asymmetric orthokeratology lens according to claim 4, characterized in that: The base arc area (1), the reversal arc area (2), the adaptation arc area (3) and the peripheral arc area (4) are integrally formed from the inside to the outside.

Images