阅读说明：本技术 一种人工晶状体及其设计方法 (Artificial lens and design method thereof ) 是由 卢英华 李韶华 陈良全 卢伙贵 张正泓 于 2020-05-07 设计创作，主要内容包括：本方案属于眼内晶体领域,具体涉及一种人工晶状体,包括晶体光学部和支撑襻,所述晶体光学部为中央透明光导区；所述支撑襻固定连接在晶体光学部的边缘,所述晶体的不同光焦度的产品的襻顶点平面到晶体的后表面顶点的距离一致,且晶体的主平面到晶体的后表面顶点的距离一致。同时,还公布了其设计方法,可快速准确的设计人工晶状体。与传统的人工晶状体相比,本方案可以使晶体在眼内位置的预测更准确,为医生提供更准确的晶体光焦度选择所使用的各种常数,更有利于医生为患者选择晶体的光焦度。(The scheme belongs to the field of intraocular lenses, and particularly relates to an intraocular lens which comprises a lens optical part and a support loop, wherein the lens optical part is a central transparent light guide area; the haptics are fixedly connected to the edge of the optical part of the crystal, the distances from the plane of the vertex of the haptics of products with different focal powers of the crystal to the vertex of the back surface of the crystal are consistent, and the distances from the main plane of the crystal to the vertex of the back surface of the crystal are consistent. Meanwhile, a design method of the artificial lens is also disclosed, and the artificial lens can be designed quickly and accurately. Compared with the traditional artificial lens, the scheme can ensure that the prediction of the lens in the intraocular position is more accurate, provides doctors with more accurate various constants for selecting the focal power of the lens, and is more beneficial to the doctors to select the focal power of the lens for patients.)

1. An intraocular lens, characterized by: the lens comprises a lens optical part and a support loop, wherein the lens optical part is a central transparent light guide area; the support loop is fixedly connected to the edge of the optic part of the crystal, the distances from the plane of the loop top point of the crystal to the top point of the back surface of the crystal are consistent, the distances from the main plane of the crystal to the top point of the back surface of the crystal are consistent, and the back surface of the crystal is close to the optical surface of the back capsule.

2. An intraocular lens according to claim 1 wherein: the principal plane of the crystal is located between or in front of the back surface apex and the front surface apex of the crystal.

3. A method of designing an intraocular lens, comprising: the method comprises the following steps:

the method comprises the following steps: designing an optical zone;

the distance from the main plane of the crystal to the vertex of the rear surface of the crystal is consistent by continuously iterative optimization of the curvature radius and the aspheric coefficient in the optical design of the two optical surfaces of the crystal; simultaneously, the spherical aberration and the focal power of the crystal are optimized until the design requirements are met;

step two: designing a loop area; the distance between the plane of the vertex of the haptic and the vertex of the back surface of the crystal is consistent by changing the included angle of the haptic.

4. An intraocular lens according to claim 3 wherein: the position of the principal plane of the crystal is obtained by using ray tracing in the optical software, so that all crystals with different focal powers are guaranteed to have the same d₂A value, and d₂Positive values, meaning that the main plane is located before the vertex of the rear surface.

5. An intraocular lens according to claim 4 wherein: the distance between the plane of the vertex of the loop of the crystal with different focal powers and the vertex of the back surface of the crystal is kept consistent:

the distance between the optical edge of the back surface of the crystal and the plane of the disc is changed by changing the included angle of the haptics or the connecting position of the haptics on the crystal optical part.

6. A method of designing an intraocular lens according to claim 3, wherein: and continuously and iteratively optimizing the curvature radius and the aspheric surface coefficient by using matlab design software.

7. A method of designing an intraocular lens according to claim 3, wherein: the zemax design software was used to optimize the spherical aberration and power of the crystals.

Technical Field

This scheme belongs to intraocular lens field, concretely relates to intraocular lens.

Background

Intraocular lenses have different optical power values and the surgeon needs to select a lens with the correct optical power value for the patient prior to surgery. The power of the intraocular lens required by different patients varies from eye to eye. The person can be matched with the glasses for optometry by changing the degree of the glasses so that the customer can be satisfied subjectively. However, the artificial lens is implanted inside the eye and cannot be realized by "trial" but can be "predicted" only by a certain method.

At present, many calculation formulas for the power of the intraocular lens are selected for patients, the key point in the formulas is to predict the position of the lens in the human eye after the lens is implanted, and manufacturers can provide constants for predicting the power according to the statistical result of the clinical use data of products, wherein the constants reflect the position of the lens in the eye after the lens is implanted in the human eye.

If a given IOL from a manufacturer has multiple powers, it is necessary to ensure that the constants of the product are consistent for all powers, such as the A constant of the STK/T equation. These constants are now obtained mainly by collecting clinical data after marketing of the product and by reverse statistical analysis. Such a method has the following problems: for a newly marketed product, it is difficult to obtain the correct usage constants due to lack of clinical data; at the same time, there must be a deviation between individuals of different power products and the results of the statistical analysis.

Meanwhile, some manufacturers take the constants into consideration during the optical design process, the main method is to ensure that the main plane of the crystal keeps constant relative to the edge position of the crystal by adjusting the optical design of the front and back surfaces of the crystal, and meanwhile, the design of the fixed loop ensures that loops of products with different focal powers are consistent, the loops are compressed by an equatorial capsular bag connected with ciliary muscles, and the position of an optical area is not displaced relative to a stretching state by supposing that the compression does not cause the displacement of the optical area. However, since the position of the lens in the eye is not only relative to the equator of the capsular bag to which the ciliary muscle is attached, but the posterior surface of the lens will be compressed by the posterior capsule of the capsular bag, both effects will affect the position of the lens. The distance between the vertex of the back surface and the plane of the vertex of the loop is different due to different thicknesses of the crystals with different focal powers, so that the compression of the posterior capsular sac is inconsistent, the compression of the crystals with the same height is more obvious, the crystals are moved forwards, and the predicted positions of the crystals in the eyes are obviously deviated from the actual positions. Current methods result in an inaccurate prediction of the location of the lens within the eye. Differences in the prediction of the location of the lens within the eye will result in deviations in the lens power selected by the physician for the patient, thereby affecting the post-operative visual quality of the patient.

Therefore, there is a need for an intraocular lens having lenses of different focal powers with the same constants while ensuring accuracy of the predicted position within the eye, thereby facilitating the selection of the focal power of the lens by the surgeon for the patient.

Disclosure of Invention

The scheme provides an artificial lens, so that the prediction of the lens in the intraocular position is more accurate, and the selection of the focal power of the lens for a patient by a doctor is more facilitated.

The main plane in the scheme refers in particular to a second main plane or an image space main plane.

In order to achieve the above object, the present invention provides an intraocular lens comprising a lens optic and haptics, the lens optic being a central transparent light-guiding region; the haptics are fixedly connected to the edge of the optical part of the crystal, the distances from the plane of the vertex of the haptics of the crystals with different focal powers to the vertex of the back surface of the crystal are consistent, and the distances from the main plane of the crystal to the vertex of the back surface of the crystal are consistent.

The principle and the beneficial effect of the scheme are that: the proposal not only ensures the influence of the constraint action of the equator structure of the capsular bag on the intraocular position of the crystal, but also eliminates the intraocular position offset of the crystal caused by inconsistent compression of the capsular sac behind the capsular bag. The scheme can ensure that the prediction of the lens in the intraocular position is more accurate, and is more beneficial to a doctor to select the focal power of the lens for a patient.

Further, the principal plane of the crystal is located between or in front of the back surface apex and the front surface apex of the crystal.

Further, another object of the present invention is to provide a method for designing an intraocular lens, comprising the following steps:

the method comprises the following steps: designing an optical zone;

the distances from the main planes of the crystals with different focal powers to the vertex of the rear surface of the crystal are consistent by continuously iterative optimization of the curvature radius and the aspheric coefficients in the optical design of the two optical surfaces of the crystal; simultaneously, the spherical aberration and the focal power of the crystal are optimized until the design requirements are met;

step two: designing a loop area; the distance between the vertex plane of the haptics and the posterior surface of the crystal is consistent by changing the size of the included angle of the haptics or the connecting position of the haptics and the edge of the optical part.

Further, the position of the principal plane of the crystal is obtained by using ray tracing in the optical software, so that all crystals with different focal powers should be guaranteed to have the same d₂A value, and d₂Positive values.

Further, matlab design software is used for continuously and iteratively optimizing the curvature radius and the aspheric surface coefficient. And Matlab software is simple to operate and accurate in data.

Further, zemax and other design software is used for optimizing the spherical aberration and the focal power of the crystal. The zemax software is simple to operate and accurate in data.

Drawings

Fig. 1 is a schematic structural diagram of an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of an embodiment of the present invention.

Detailed Description

The following is further detailed by the specific embodiments:

reference numerals in the drawings of the specification include: cornea 10, anterior capsule 20, posterior capsule 30, capsule equator 40, lens 50, haptics 60, haptic angle 70, haptic apex plane 81.

As shown in FIG. 1, which is a schematic representation of an intraocular lens 50 in an eye, the intraocular lens is mounted in a capsular bag with the optically posterior surface adjacent to or abutting the posterior capsule 30, the haptics are supported in the capsular equator 40, and the outermost layer of the eye is the cornea 10.

The specific structure of the lens is shown in fig. 2 and consists essentially of two parts, a lens optic and haptics 60. The lens optic is a central transparent light guiding area with haptics 60 attached at the edges of the lens optic. The angle between the optic face edge plane of the lens optic and the haptics 60 is then the haptic angle 70. The haptic apex planes 81 of the crystal are uniformly spaced from the crystal's posterior surface apex, and the principal planes of the crystal are uniformly spaced from the crystal's posterior surface apex.

It is of course also possible that the principal plane of the crystal is located between the rear surface apex and the front surface apex of the crystal, but is arranged in front of the front surface apex.

The specific design method of the intraocular lens 50 includes:

step one, designing an optical area:

continuously iterating and optimizing the curvature radius and the aspheric coefficient in the optical design of the two optical surfaces of the crystal by using matlab design software, so that the distance from the main plane of the crystal to the vertex of the rear surface of the crystal is consistent; simultaneously, zemax design software is used for optimizing the spherical aberration and the focal power of the crystal until the design requirements are met; all crystals of different powers should be guaranteed to have the same d₂A value, and d₂Is positive, in this embodiment, the d2 value is 0.324mm

Step two, designing a loop area;

by varying the amount of the included haptic angle 70 or the haptic-optic junction position, the distance from the haptic apex plane 81 to the posterior surface of the lens is made uniform, i.e., H in the illustration₀And d_pAre equal to each other, thereby obtaining the intraocular lens 50.

The refractive index of the selected material is 1.520, the optical caliber of the product is 6.0mm, the product is a spherical crystal, and the H value is set to be 0.40 mm. Three intraocular lenses 50 of different focal powers were designed according to the above method, with the following specific parameters:

the same value of d2, 0.324mm for both lenses 50 of different powers ensures a consistent distance from the principal plane of the lens to the apex of the posterior surface of the lens. Meanwhile, the loop included angles 70 with different focal powers are different, in the scheme, the loop included angle 70 corresponding to the 10.0D focal power is the smallest, and the loop included angle 70 corresponding to the 30.0D focal power is the largest. By adjusting the included haptic angle 70, it is ensured that the vertex plane 81 of the haptic of the crystal is at a uniform distance from the vertex of the posterior surface of the crystal.

The design not only ensures the influence of the equatorial structure of the capsular bag on the intraocular position of the lens, but also eliminates the intraocular position deviation of the lens caused by the inconsistent compression of the capsular sac 30 behind the capsular bag. Compared with the traditional artificial lens 50, the scheme can ensure that the prediction of the lens in the intraocular position is more accurate, and is more beneficial for a doctor to select the focal power of the lens for a patient.

The foregoing is merely an example of the present invention and common general knowledge of known specific structures and features of the embodiments is not described herein in any greater detail. It should be noted that, for those skilled in the art, without departing from the structure of the present invention, several changes and modifications can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicability of the patent. The scope of the claims of the present application shall be determined by the contents of the claims, and the description of the embodiments and the like in the specification shall be used to explain the contents of the claims.