CN119908876B

CN119908876B - Wavefront-controlled continuous vision intraocular lens

Info

Publication number: CN119908876B
Application number: CN202510408826.XA
Authority: CN
Inventors: 叶增强; 何川; 何满林
Original assignee: Jingtian Medical Technology Co ltd
Current assignee: Jingtian Medical Technology Co ltd
Priority date: 2025-04-02
Filing date: 2025-04-02
Publication date: 2025-07-15
Anticipated expiration: 2045-04-02
Also published as: CN119908876A

Abstract

The present invention provides a wavefront-regulated continuous-range intraocular lens, which deeply regulates the wavefront aberration of the intraocular lens through Zernike polynomials, and controls the aberration of different areas of the intraocular lens optical surface to regulate the distribution of the wavefront, so that the focus is no longer concentrated on a certain point, but is continuously distributed within a certain focal depth (1.5D to 3.5D), thereby extending the depth of field and providing continuous and seamless switching of vision from far to near, without switching the focus between different distances. Through Zernike wavefront regulation, the connection between the focus is smoother, there is no fixed focus, and a full continuous range of vision is provided while the light energy utilization rate is high, so that patients can obtain higher dark vision after surgery.

Description

Wavefront-controlled continuous vision intraocular lens

Technical Field

The application relates to an intraocular lens in the field of medical instruments, in particular to a wavefront-controlled continuous vision intraocular lens.

Background

An intraocular lens is an implantable medical device made of a polymer material and used for replacing an aged natural lens of a human eye and being placed in the anterior chamber or the posterior chamber of the human eye to treat cataract or ametropia.

The optical design of multifocal intraocular lenses is generally divided into diffractive and refractive types, which focus the light in a number of concentrated focal points by different means, to the extent that the distance a patient can see is increased. However, because the light concentration at different focuses is relatively high, glare, halation or starburst phenomena occur at night or in a dim light environment, affecting visual comfort. Meanwhile, since the multifocal intraocular lens provides at least two or more foci, it may be difficult for the brain to adapt to the focus switching, and visual confusion or blurring may occur. For example, publication number CN110062899a discloses that an intraocular lens with zone-by-zone step height control is constructed by making a saw-tooth optical step structure on the front or back surface of the lens, and that parallel light incident on the human eye is focused through diffraction onto several different diffraction orders having different refractive powers and different light energy distribution ratios when passing through the fresnel zone. At the same time, most of the light is diffracted to useless focus to form stray light, which causes visual influence, so that the low light energy utilization rate is also a great problem of the diffraction type intraocular lens.

The above reasons have resulted in the creation of extended depth-of-field intraocular lenses, which have caused a number of difficulties in clinical use of multifocal intraocular lenses. There are several general problems with existing extended depth of field intraocular lenses. For example, patent publication CN104755012a discloses a multi-ring lens, a system and a method for extending focal depth, which adopts ECHELETTE diffraction grating technology, distributes light to different focal points through special diffraction grating design, prolongs the depth of field, enables a patient to obtain clear vision at different distances, adopts two small-step diffraction steps to design a small-addition-power diffraction crystal, and adds the self depth of field of human eyes to realize the effect of depth of field delay, but is still based on diffraction technology, the problem of stray light cannot be avoided, and the light energy utilization rate is lower than 85%. For example, patent publication No. CN115778631a discloses that the focusing degree of the main focus is adjusted by adjusting the high order term coefficient of the aspherical surface, so that the light spot is diffused, and the effect of extending the depth of field is achieved. The patent publication No. CN 110711050A discloses a technology for improving the traditional aspherical intraocular lens and the astigmatic intraocular lens by using Zernike polynomials to represent optical surfaces, wherein one surface is used as an asymmetric structure, so that the aberration caused by partial cornea can be reduced, better effect of far vision can be realized to a certain extent, but continuous vision cannot be realized, good vision cannot be obtained at a middle and near distance, and continuity of vision is lost.

Disclosure of Invention

The invention aims at the problem of discontinuous vision of the intraocular lens in the prior art, provides an intraocular lens, adjusts wave front aberration of the intraocular lens by using Zernike polynomials in different areas separately in different areas, adjusts and controls wave front distribution by controlling the aberration of different areas of the optical surface of the intraocular lens, so that focuses are not focused on a certain point any more, but continuously distributed in a range of a certain focal depth (1.5D to 3.5D), the depth of field is prolonged, and vision of continuous and seamless switching from far to near is provided without switching focuses among different distances. The specific technical scheme is as follows:

An intraocular lens realizing depth of field extension through wavefront regulation comprises an optical part and a mechanical part, wherein one surface of the optical part is set to be a free curved surface formed by Zernike wavefront regulation, and the other corresponding surface is a spherical surface or an aspheric surface;

The free curved surface is divided into more than 2 continuous areas from the center outwards, the aberration type of each area is selected and set according to the Zernike polynomial, and the aberration value is determined The adjacent areas are set as different types of aberration, and the polar coordinates of the surface type curve of the free curved surface are as follows:

(1)

Wherein, the For the operating wavelength, n2 is the refractive index of the intraocular lens, n1 is the refractive index of the aqueous humor,In polar form of the wavefront function of the curved surface of the intraocular lens,The confirmation is adjusted and deduced by formulas (2) - (4),

(2)

(3)

(4)

Wherein n is the radial order (n≥0), m is the angular frequency (|m≥n, and n- |m| is even), ρ is the normalized radial coordinate (0≥1), θ is the angular coordinate (0≥2 pi); Is an adjustment coefficient, which represents the weight of the corresponding aberration, the value of k is-5-10, k is an integer index variable in a summation formula, and gradually increases from 0 until the upper limit is reached 。

The polar relation (1) of the present invention can be obtained by r=r ₀ , Zf(r)= r₀ And the free-form surface sagittal height Zf (r) and the distance between the radial coordinate r and the center point of the lens on the optical axis are converted into a Cartesian coordinate system relational expression.

Further, the haptics are L-shaped, C-shaped or plate-shaped haptics.

Further, the diameter range of the free curved surface is 5.5 mm-7.5 mm, the free curved surface is divided into 2-5 areas from the center outwards, and the diameter of each area is increased by 1-1.5mm.

Further, the Zernike polynomials may be selected from 0-multiple orders, and the aberration types of the respective regions may be translational, defocus, astigmatism, spherical aberration, tilt, coma, or the like.

Further, the optical surface type expression of the aspheric surface adopts the following formula:

(5)

wherein Z (R) is an aspheric surface type function, R is a radial coordinate, a distance from a lens center point on an optical axis, R is a curvature radius of a basic spherical surface, K is a quadric surface coefficient, Is an aspherical high order term coefficient, i=1, 2,..n, n is a natural number not less than 1, when k=0, and the aspherical high order term coefficientWhen both are 0, the surface shape is a spherical surface.

Wherein, a 0-multi-order Zernike polynomial can be used in the present invention, the first 4 orders are listed in the following table symbolically, and the wavefront diagram of the corresponding concentrated aberration mode is shown in FIG. 1.

List one

According to the invention, the adjusted optical curved surface is obtained according to the formulas (2) - (4) by adjusting the corresponding weights of different aberrations, the setting proportion of different types of aberration weights is confirmed by computer calculation with reference to the focus condition after ray tracing during specific adjustment confirmation, a lens is placed in a theoretical eye model, the aberration weights of different areas are modified, and then optimization adjustment is performed in real time until an optimal solution is taken out, so that the focus is prolonged and the optimal weight value of a breakpoint is not generated.

The invention relates to an artificial lens for wave front regulation by using a zoned Zernike polynomial, which has the advantages of being capable of realizing no stray light and 100% of light energy utilization rate, ensuring that all incident light rays become part of an effective focus so as to avoid phenomena such as glare, ensuring that the Zernike polynomial has high degree of regulation on wave front, avoiding limitation among zones, freely controlling the aberration of different zones, directly controlling the imaging result, converting the imaging result into a sagittal plane type of a free curved surface, realizing the formation of a highly free curved surface on the optical surface of the artificial lens, realizing a higher depth of field range compared with a higher aspheric surface, ensuring that the junction between the focus and the focus is smoother, no fixed focus compared with the focus formed by diffraction, ensuring that the focus has no concentration and useless diffraction orders so as to avoid stray light, and ensuring that a patient can obtain higher visual acuity after operation due to the provision of a full continuous viewing path and high light energy utilization rate.

Drawings

FIG. 1 is a wavefront map of a concentrated aberration pattern;

FIG. 2 is a schematic view of an artificial lens structure;

FIG. 3 is a wavefront curve of the free-form surface of example 1;

FIG. 4 is a schematic diagram of the sagittal profile of example 1;

FIG. 5 is a diagram of an intraocular lens of example 1 in comparison to prior art single and multi-focal intraocular lenses;

FIG. 6 is a wavefront curve of the free-form surface of example 2;

FIG. 7 is a schematic diagram of the sagittal profile of example 2;

figure 8 is a graph comparing an intraocular lens of example 2 with prior art single and multi-focal intraocular lenses.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Example 1

In this embodiment, the intraocular lens structure is shown in fig. 2, the optical part diameter of the free curved surface is 6mm, the free curved surface is divided into 4 areas, the first area is adjusted to zero aberration through a Zernike polynomial to achieve good far vision, the second area is adjusted to positive spherical aberration through the Zernike polynomial to the surface range, the weight of the second area is set to 0.42 to achieve far vision to middle distance deviation, but the setting of aberration coefficients avoids forming vision break points to enable focal depth to be continuous, the third area is used for increasing negative spherical aberration while increasing defocus aberration, the weight distribution of the third area is set to 0.27 and-0.09 to enable vision to be continuous with middle vision while shifting to near distance, the fourth area is set to zero aberration area to enable the near three vision distance continuous vision, the wavefront curve of the free curved surface set in the manner is shown in fig. 3 to be improved in dark environment, after the wavefront conversion high distribution is brought into basic light, and the high-order vision distribution is added into a Cartesian coordinate system, and the high-order image is shown in fig. 4.

The other surface in this embodiment is set to be a higher order aspherical surface, and detailed setting parameters of two different optical surfaces are shown in the following tables two and three. Thus, the patient implanted with the intraocular lens can see far, middle and near clearly at the same time, visual interference is greatly reduced, the Modulation Transfer Function (MTF) of the embodiment is tested in a model eye required by ISO 11979-2:2024 5 th edition ophthalmic implant-intraocular lens, the response curve of the MTF is compared with that of the monofocal intraocular lens and the multifocal intraocular lens in the prior art, the MTF value is not continuously lower than 0.1 in the response curve of the MTF of the intraocular lens in the prior art, the focal depth range of the MTF is larger than 0.1 and is larger than 2.5D, the continuity of the vision is good, and the continuity of the vision is far better than that of the prior art.

And (II) table:

table three:

example 2

In this example, the free-form surface has an optical portion diameter of 6.5mm, the free-form surface is divided into 3 regions, the first region is adjusted to be a positive spherical aberration by a Zernike polynomial, the distance from the far focus to the middle distance is directly displaced, the weight distribution is set to be 0.33, the second region is arranged to increase a negative spherical aberration while the defocus aberration is set to the surface by the Zernike polynomial, the near focus is set, the weight distribution is set to be 0.56 and-0.12, the third region is arranged to be a region gradually increasing with the spherical aberration of the radial distance, the weight value is 0.11r (r is the radial distance from the surface to the center), and the continuity between the near vision and the middle vision is increased while the vision in a dark environment is enhanced. The wavefront profile of the free-form surface set in this way is shown in fig. 6, and the sagittal profile of this embodiment is shown in fig. 7 by adding a few drops to the wavefront conversion sagittal profile after bringing in the base power.

The other surface in this embodiment is set to be a higher order aspherical surface, and detailed setting parameters of two different optical surfaces are shown in the following table. In this case, the front and rear surface patterns of the intraocular lens according to the present invention were obtained, and the present invention was put into a model eye required by ISO 11979-2:2024, 5 th edition of ophthalmic implant-intraocular lens, and its Modulation Transfer Function (MTF) response curve with defocus was tested, and compared with the monofocal and multifocal intraocular lenses of the prior art, the result was that, as shown in fig. 8, the MTF value was not continuously lower than 0.1 in the response curve with defocus, and the focal depth range where the MTF was greater than 0.1 was greater than 3D, and the vision continuity was good. The continuity of the vision range is far better than that of the prior art, and the vision on each vision range is good, so that the effect of full vision range continuity is realized.

Table four:

Table five:

While the preferred embodiments of the present patent have been described in detail, the present patent is not limited to the above embodiments, and various changes may be made without departing from the spirit of the present patent within the knowledge of one of ordinary skill in the art.

Claims

1. A wavefront-controlled continuous vision intraocular lens is characterized by comprising an optical part and a mechanical part, wherein one surface of the optical part is set to be a free-form surface formed by Zernike wavefront control, and the other surface is a spherical surface or an aspheric surface;

The free-form surface diameter range is 5.5 mm-7.5 mm, the free-form surface diameter range is divided into 2-5 areas from the center outwards successively, the diameter of each area is increased by 1-1.5mm, the aberration types of each area are selected and set according to a Zernike polynomial, the aberration value W (rho, theta) is determined, the adjacent areas are set to be different types of aberration, zf (rho, theta) is the polar coordinate function of the free-form surface curve and the polar coordinate function of the free-form surface curve and the wavefront of the intraocular lens curve The relation of (2) is as follows:

Wherein lambda is the working wavelength, n2 is the refractive index of the artificial lens, n1 is the refractive index of aqueous humor, The validation is adjusted and derived by formulas (2) - (4):

wherein n is the radial order, n is equal to or greater than 0;m is the angular frequency, |m| is equal to or less than n, and n-m| is an even number; is a radial function of Zernike polynomials, ρ is a normalized radial coordinate, ρ is 0≤1, θ is an angular coordinate, 0≤θ <2π;

Is an adjustment coefficient, which represents the weight of the corresponding aberration, the value of k is-5-10, k is an integer index variable in a summation formula, and gradually increases from 0 until the upper limit is reached

2. The wavefront controlled continuous view intraocular lens of claim 1 wherein the haptics are L-shaped, C-shaped or plate-shaped haptics.

3. The wavefront-controlled continuous view intraocular lens of claim 1 wherein the Zernike polynomials are of 0-multiple order and the aberration types of the individual regions are translational, defocus, astigmatism, spherical, tilt or coma.

4. The wavefront-controlled continuous view intraocular lens of claim 1 wherein said aspheric optical surface shape is expressed as follows:

wherein Z (R) is an aspherical surface type function, R is a radial coordinate, a distance from a lens center point on an optical axis, R is a curvature radius of a base sphere, K is a quadric surface coefficient, αi is an aspherical high order term coefficient, i=1, 2, n, n is a natural number not less than 1, and when k=0 and the aspherical high order term coefficients αi are both 0, the surface type is a sphere.