The present invention relates to the technical field of optical elements, in particular to an expanded focal depth type implantable contact lens and a preparation method thereof.
An implantable contact lens is an implantable collamer lens (ICL), i.e., an intraocular lens, placed in the posterior chamber.
Due to poor eye care habits of people, long-term use of electronic devices, less outdoor activities and other factors, as well as long-term close eye use cause abnormal growth of the eye axis, thus causing refractive errors. With the development of science and technology and the increasing demand for vision in human beings, many correction methods have been developed to restore the ability of patients to regain their visions. Compared with a corneal laser surgery, traditional framed glasses, contact lenses and other correction methods, intraocular lenses are chosen by more and more young patients because they do not damage the cornea, do not need to be removed, and can be removed and replaced repeatedly.
However, with the increase of age, the ability of ciliary muscle adjustment of myopia patients has weakened, so presbyopia appears, resulting in patients suffering from both myopia and presbyopia. Existing products or methods (e.g., framed glasses, contact lenses, laser corneal surgery, and ICL implantation) for correcting refractive errors such as myopia, presbyopia and astigmatism cannot correct myopia and presbyopia at the same time.
Accordingly, how to design a lens intraocular lens that solves the problems of myopia and presbyopia at the same time and improve the visual quality of patients is a technical problem that needs to be solved by those skilled in the art.
The present invention provides an expanded focal depth type implantable contact lens and a preparation method thereof, which have the ability to adjust focal depth expansion, and to solve the problems of both myopia and presbyopia at the same time.
In order to achieve the above effects, the technical solution of the present invention is summarized as follows.
An expanded focal depth type implantable contact lens includes an optical body, a first supporting loop and a second supporting loop, wherein the optical body, the first supporting loop and the second supporting loop are of an integrated structure, are made of the same material and are integrally formed, and the optical body is located between the first supporting loop and the second supporting loop; and said optical body is composed of two optical surfaces that one optical surface is a plane, and the other optical surface is a free-form surface with a focal depth expanding function.
Further, one of said optical surfaces of the optical body satisfies a free-form surface design principle in which a determination method is as follows: an arbitrary spatial rectangular coordinate system is established by taking a vertex of said optical surface as an origin O and an optical axis as a Z-axis, and a coordinate axis X and a coordinate axis Y of the coordinate system are tangent to said free-form surface.
Further, a design process of said free-form surface is as follows:
in which: n1 and n2 are refractive indices of an incident medium and an emergent medium respectively, the refractive indices of the incident medium and the emergent medium are known quantities, and the incident medium represents the intraocular lens; an included angle γ0 between the normal direction of the sub-surface A0 and the optical axis is solved according to simultaneous equations (2) and (3), γ0 being expressed as:
In the above scheme, the intraocular lens of the present invention has a plurality of focal points, and a long focal depth range.
An emergent ray {right arrow over (I)}1 obtained after an incident ray is refracted by passing through the sub-surface A0 may be obtained according to θ1, wherein {right arrow over (I)}1 is characterized by an equation as {right arrow over (I)}1=C|{right arrow over (I)}0|(sin θ1,cos θ1), in which C is a transmittance of the intraocular lens.
Further, an effective optical zone of said optical body has a diameter ranging from 4 mm to 6 mm.
Further, the focal length f0 of said optical body is determined by a dioptric power of the optical body, and the dioptric power ranges from 0 D to −30 D.
Further, said optical body is made of hydrophilic polyacrylate.
Further, said optical body has a refractive index of 1.437 at 35° C.
Further, said first supporting loop and said second supporting loop each have a thickness of 0.08 mm to 0.15 mm.
A preparation method of an expanded focal depth type implantable contact lens is used to design the expanded focal depth type implantable contact lens, the preparation method including the following steps:
It may be understood that the normal vector of the sub-surface passes through the sub-surface and is perpendicular to a tangent plane of the sub-surface, the sub-surface is a miniature spherical surface, and the sub-surface may be solved by means of a geometric relationship of the normal vectors of the sub-surface. In step 1, a curvature r of the basic spherical surface that satisfies a dioptric power requirement of the optical body is optimized, wherein the optimization is completed by adjusting a parameter of the basic spherical surface by zemax.
The sub-surface A1 has a corresponding focal length of f1, and the sub-surface Ai has a corresponding focal length of fi.
Compared with the prior art, the technical solutions of the present invention have the following beneficial effects.
According to the present invention, a focal length expansion technology is applied to phakic intraocular lens, so that a focal depth adjusting capacity of the lens is increased on the basis of correcting myopia.
1. According to the present invention, the free-form surface is introduced; the focal depth expansion technology is applied to phakic intraocular lens; a focal depth is expanded; certain adjusting capacity is provided while myopia is corrected; the surface is smooth and does not change suddenly; and glare and halo cannot be introduced, such that presbyopia of a patient is corrected while myopia is corrected, thereby achieving an excellent visual effect.
2. According to the present invention, a spherical or aspheric surface of the ordinary phakic intraocular lens is replaced with the free-form surface, which effectively controls the lens thickness, and is more universal.
3. The phakic intraocular lens of the present invention is formed integrally, has a simple structure and good stability, is suitable for complex ophthalmic fluid environments, and is not easy to induce complications.
The accompanying drawings are for an illustrative purpose only and cannot be construed as limitations on the present invention. In order to better illustrate the embodiments, certain components in the accompanying drawings will be omitted, increased or reduced, and do not represent the dimension of an actual product. For those skilled in the art, it may be understood that certain well-known structures and their descriptions in the accompanying drawings may be omitted.
In order to make the objectives, technical solutions and advantages of the embodiments of the present invention more clearly, the technical solutions in the embodiments of the present invention will be described clearly and completely in conjunction with the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are merely some embodiments, rather than all embodiments, of the present invention. Based on the embodiments of the present invention, all other embodiments derived by a person of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
For ease of understanding, referring to
The free-form surface is divided into a group of sub-surfaces according to a geometric iteration method, such that the free-form surface is discretized, the discretized free-form surface being represented by an envelope surface of the group of sub-surfaces; said free-form surface is rotationally symmetrical, and a sub-surface on one meridian is discussed separately to replace all the sub-surfaces;
It should be noted that the included angle γ0 between the normal direction of the sub-surface Ai and the optical axis solved according to simultaneous equations (2) and (3) is solved according to equivalence relationships in the equations (2) and (3). The derivation process is as shown in
A preparation method of an expanded focal depth type implantable contact lens is used to design the expanded focal depth type implantable contact lens, the preparation method including the following steps:
According to the present invention, the free-form surface is introduced; a focal depth expansion technology is applied to the phakic intraocular lens; a focal depth is expanded; certain adjusting capacity is provided while myopia is corrected; the surface is smooth and does not change suddenly; and glare and halo are not introduced, such that presbyopia of a patient is corrected while myopia is corrected, and thus the patient can achieve a clear vision.
It should be noted that presbyopia is caused by the weakening of the patient's ability to adjust the lenses of the human eyes. The lens of the present invention provides a part of the adjusting capacity to correct the presbyopia. The adjusting capacity allows patients to still see clearly in a relatively large range of dioptric power (+1 D to +2.5 D) at an expanded focal length with fully correcting farsighted vision and without using an adjusting function of own lenses of the human eyes.
Specifically, on the basis of Embodiment 1, the scheme is explained in combination with specific embodiments, and the technical effect of this scheme is further reflected. Specifically:
In the present embodiment, the phakic intraocular lens is introduced into an ocular model required in ISO11979-2, and an out-of-focus MTF value is obtained by means of testing with an optical device.
Specifically, on the basis of Embodiment 1, the scheme is explained in combination with specific embodiments, and the technical effect of this scheme is further reflected. Specifically:
A preparation method of an expanded focal depth type implantable contact lens in the present embodiment includes:
In the present embodiment, the phakic intraocular lens is introduced into an ocular model required in ISO11979-2, and an out-of-focus MTF value is obtained by means of testing with an optical device.
Specifically, on the basis of Embodiment 1, the scheme is explained in combination with specific embodiments, and the technical effect of this scheme is further reflected. Specifically:
A preparation method of an expanded focal depth type implantable contact lens in the present embodiment includes:
In the present embodiment, the phakic intraocular lens is introduced into an ocular model required in ISO11979-2, and an out-of-focus MTF value is obtained by means of testing with an optical device.
It may be understood that the center point and the normal vector in the above embodiment are represented by two points, which refer to a coordinate representation in a coordinate system Y-Z, and at this time, X coordinates are omitted.
Obviously, the above embodiments of the present invention are only examples given to clearly illustrate the present invention, without any limitation of implementations of the present invention. For a person of ordinary skill in the art, other different forms of changes or variations can be made on the basis of the above description. There is no need and cannot be exhaustive of all implementations. Any modification, equivalent replacement, improvement and so on made within the spirit and principle of the present invention shall be encompassed by the protection scope of the present invention.
Number | Date | Country | Kind |
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202211575612.4 | Dec 2022 | CN | national |
This application is the continuation application of International Application No. PCT/2023/132566, filed on Nov. 20, 2023, which is based upon and claims priority to Chinese Patent Application No. 202211575612.4, filed on Dec. 8, 2022, the entire contents of which are incorporated herein by reference.
Number | Date | Country | |
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Parent | PCT/CN2023/132566 | Nov 2023 | WO |
Child | 18746053 | US |