CN210982947U

CN210982947U - Cornea shaping mirror

Info

Publication number: CN210982947U
Application number: CN201921744681.7U
Authority: CN
Inventors: 王曌; 解江冰
Original assignee: Abbott Beijing Medical Technology Co ltd
Current assignee: Abbott Beijing Medical Technology Co ltd; Eyebright Medical Technology Beijing Co Ltd
Priority date: 2019-10-17
Filing date: 2019-10-17
Publication date: 2020-07-10
Anticipated expiration: 2029-10-17

Abstract

The utility model provides a plastic mirror of cornea, the plastic mirror of cornea has the internal surface towards the human eye cornea when wearing, the internal surface is including the base arc district that is located the center, the base arc district has the toric shape, base arc district constitution does, makes by the cornea after the base arc district is moulding has the regulation astigmatism, and this regulation astigmatism can compensate intraocular astigmatism. Adopt the utility model discloses, can compensate or offset intraocular astigmatism, improve people's eyesight and definition.

Description

Cornea shaping mirror

Technical Field

The utility model relates to a plastic mirror of cornea, more specifically relates to a plastic mirror of cornea that base arc district has moulding structure of astigmatism.

Background

The rigid air-permeable contact lens for cornea shaping (called cornea shaping lens for short) is a reversible and non-operative refractive correction product, generally has an inverse geometry design formed by several concentric circular arc regions, and has a base arc shaping region, an inverse arc region, a positioning region and other regions.

The base zone of orthokeratology lenses is generally designed as a sphere with a set radius of curvature, primarily for correcting myopia. Patent document 1 discloses a keratoplasty mirror having more than one curvature radius in the base curve region, in which the optical region of the cornea is shaped into several regions of different curvature radii, so that the human eye has a plurality of focal points simultaneously, and the ametropia is corrected while presbyopia is corrected. In patent document 2, there is mentioned a orthokeratology mirror having an aspherical base arc region for providing a suitable peripheral defocus or aberration. These designs all aim to shape the cornea into a 360 degree circumferential surface of rotational symmetry. Patent document 3 discloses a keratoplasty mirror, the inner surface of which is divided into a base arc area, an inversion arc area, a positioning arc area and a peripheral arc area from the center to the periphery, wherein the positioning arc area is a multi-area annular curved surface, and the positioning arc area on the inner surface of the keratoplasty mirror is designed into the multi-area annular curved surface, so as to improve the fit degree between the keratoplasty mirror and the cornea and achieve the effect of centering the lens.

Astigmatism is a low-order aberration common to human eyes, and has a direct influence on vision, and the resolution of human eyes is sharply reduced by astigmatism exceeding 0.75D. Astigmatism of human eyes is caused by different curvature radii (refractive powers) of different meridians, and light rays passing through different meridians cannot be focused (form focal points) at the same time in eyes but form two focal lines perpendicular to each other in space, which causes deformation of object images and blurred vision. The human eye is used as an optical system, the cornea and the crystalline lens are two large dioptric elements, the astigmatism of the human eye can be caused by any one of the two dioptric elements, or the two dioptric elements have astigmatism. Astigmatism has an axial direction, generally referred to as the angle between the direction of maximum/minimum power and the horizontal direction of the human eye. The astigmatism of the cornea and lens may be co-directional or non-directional.

After the orthokeratology lens is worn on the cornea with astigmatism, the central optical zone is shaped as a surface of rotational symmetry, and if the cornea of the wearer has astigmatism, the astigmatism of the cornea is corrected by wearing the orthokeratology lens. However, if the wearer has intraocular astigmatism, the intraocular astigmatism cannot be corrected after wearing the orthokeratology lens, and the visual quality is still affected, and if the direction of the corneal astigmatism and the direction of the intraocular astigmatism are originally complementary to each other, the total-eye astigmatism is increased after wearing the orthokeratology lens, so that the visual quality of the wearer is worse. The current cornea shaping mirror can not solve the problem of astigmatism in eyes.

Background art documents:

patent document 1: CN108008544A

Patent document 2: CN106291977A

Patent document 3: CN202453593U

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a plastic mirror of cornea and manufacturing method that base arc district has astigmatism correction effect, the plastic mirror of cornea can mould the cornea optics district into the astigmatism form of regulation, compensates astigmatism in the eye, reduces/corrects whole eye astigmatism.

In order to achieve the above object, the present invention relates to a corneal shaping mirror having an inner surface facing a cornea of a human eye when worn, the inner surface including a base arc zone located at a center, the base arc zone having a toric shape, the base arc zone being constituted so as to make a cornea after the base arc zone is shaped have a prescribed astigmatism which can compensate for an intraocular astigmatism.

The utility model discloses preferentially, base arc district extends with sine curve form or cosine curve form in the circumferencial direction.

The utility model discloses preferentially, the internal surface is still including being located the adapted arc district of base arc district periphery side, it has the toric shape to adapt to the arc district.

The utility model discloses preferentially, the toric surface shape in base arc district with contained angle α has between the toric surface shape of fitting the arc district, α is not less than 0 and is not less than 180.

The utility model discloses preferably, for base arc district, the biggest direction of curvature radius is called flat K direction, and curvature radius is marked as R1, and the direction that curvature radius is minimum is called steep K direction, and curvature radius is marked as R2, wherein R1 and R2 direction mutually perpendicular to the moulding mirror base arc center of cornea is the summit and establishes three-dimensional coordinate system, and wherein the optical axis direction of the moulding mirror of cornea is the Z axle, and perpendicular with the optical axis, and the face through base arc center is the base plane, and Z is the height that any point leaves the base plane on the base arc surface, base arc district shape of face satisfies the formula:

c1 and C2 are curvatures in the flat K direction and the steep K direction of the base arc region, namely: c1 is 1/R1, C2 is 1/R2, and (R, θ) is the polar coordinate of any point on the base arc surface projected to the base plane, the polar coordinate uses the base arc center as the center of a circle and the steep K direction as the polar axis.

The utility model discloses it is preferred, the flat K direction radius of curvature R1 of base arc district is 6.00 ~ 10.50mm, 7.00 ~ 10.00mm or 7.50 ~ 9.50mm, and steep K direction radius of curvature R2 is 5.42 ~ 10.26mm, 6.23 ~ 9.78mm or 6.62 ~ 9.30 mm.

The utility model discloses it is preferred, the diameter of the flat K direction of base arc district is 4.5 ~ 8.0mm, 5.0 ~ 7.0mm or 5.2 ~ 6.5 mm.

The utility model discloses it is preferred, the flat K direction shape of face height of base arc district is 10.7 ~ 101.8 mu m, 10.7 ~ 75.8 mu m or 10.7 ~ 50.2 mu m with the steep K direction shape of face height at 3.0mm diameter department difference in height.

The utility model discloses it is preferred, it is 6.00 ~ 9.50mm, 6.50 ~ 9.00mm or 7.00 ~ 8.50mm to match the curvature radius of arc district in flat K direction, is 5.42 ~ 9.43mm, 5.83 ~ 8.94mm or 6.23 ~ 8.45mm in the curvature radius of steep K direction.

The utility model provides a moulding mirror of cornea and design, manufacturing approach that base arc district has toric surface design adopts the utility model discloses, can make the cornea have regulation astigmatism after moulding, this regulation astigmatism can equal with intraocular astigmatism size, opposite direction to can compensate or offset intraocular astigmatism, improve people's eye vision and definition. In order to realize the directional stability of astigmatism, the orthokeratology mirror has a toric design in an adaptive arc area, and the relative position stability between the orthokeratology mirror and the cornea is realized through the adaptive matching between tear fluid and corneal topography. And the included angle between the base arc area and the adaptive arc area is stable, so that the astigmatic moulding direction of the cornea is limited to be stable every night by the base arc area, and the stability of astigmatic correction can be ensured.

< definition of terms >

The following definitions apply to terms used in this specification unless otherwise specified.

Toric surfaces, an optical surface with different radii of curvature in different meridian directions, are also called Toric surfaces, Toric surfaces.

The basal arc zone (BC) is positioned at the most central part of the cornea shaping mirror and is the inner surface of the optical zone and is used for pressing the front surface of the cornea and shaping the front surface of the cornea into the shape, and the area of the shaped cornea is the optical zone and plays a role in optical imaging.

The reverse arc area (RC) is a second area closely connected with the base arc area, and plays a role in connecting the base arc area and the adaptive arc area, forming a gap between the orthokeratology lens and the front surface of the cornea, and playing a role in storing tears and promoting the circulation of the tears.

The adaptive arc Area (AC) is also called a positioning arc area, a matching arc area and the like, is close to the reversal arc area, and the area is matched with the shape of the cornea to play a role in positioning.

The side arc area (PC) is optional, is positioned at the outermost edge of the orthokeratology lens, is tightly connected with the adaptive arc area, is generally flatter than the adaptive arc area, and forms a certain tilting angle with the surface of the cornea, thereby ensuring the exchange and the circulation of tears and oxygen around the cornea and the orthokeratology lens.

Moreover, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of inconsistency, the present specification and the definitions included therein shall control.

Drawings

FIG. 1 is a view of a orthokeratology mirror as seen in the direction of the optical axis;

FIG. 2 is a view of the base arc region as seen in the direction of the optical axis;

FIG. 3 is an oblique view of the base arc region;

fig. 4 is a graph of the change in base arc zone circumferential rise.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

< overview of corneal remodelling mirror Structure >

FIG. 1 is a view of a orthokeratology mirror as seen in the direction of the optical axis; FIG. 2 is a view of the base arc region as seen in the direction of the optical axis; FIG. 3 is an oblique view of the base arc region; fig. 4 is a graph of the change in base arc zone circumferential rise.

As shown in fig. 1, the orthokeratology mirror 10 is distributed with a base arc area 1, a reversal arc area 2, a matching arc area 3 and a side arc area 4 from the center to the outside, wherein the base arc area 1 has a toroidal surface design, the curvature radius is different in different meridian directions, the front view shape is similar to an ellipse, and the orthokeratology mirror is used for shaping the cornea into a corresponding toroidal surface shape, and provides the amount of astigmatism while correcting myopia; the adaptive arc area 3 has a toroidal curved surface design, the front view shape tends to be elliptical and is consistent with the shape of the cornea in the area, and the function of positioning is achieved; the reverse arc area 2 is the natural connection of the base arc area and the adaptive arc area, the edge shape close to the base arc area is matched with the base arc area, and the edge shape close to the adaptive arc area is matched with the adaptive arc area; the side arc area 4 is designed to be normal round, slightly tilted than the shape of the cornea, and plays a role in the circulation of tears. In some embodiments, the adaptive arc region 3 and the side arc region 4 are the same arc, and are not distinguished.

The base arc region 1 has different radii of curvature at different meridians, and in the direction of 360 °, the direction with the largest radius of curvature is called the flat K direction (denoted as y1, coinciding with the major axis of the ellipse when viewed along the optical axis, see fig. 3), the radius of curvature is denoted as R1, the direction with the smallest radius of curvature is called the steep K direction (denoted as x1, coinciding with the minor axis of the ellipse when viewed along the optical axis, see fig. 3), and the radius of curvature is denoted as R2, wherein the directions of R1 and R2 are perpendicular to each other.

The method comprises the following steps of establishing a three-dimensional coordinate system by taking the center of a base arc area 1 of the corneal shaping mirror as a vertex, wherein the optical axis direction of the corneal shaping mirror is a Z axis which is perpendicular to the optical axis, a surface passing through the center of the base arc area is a base plane, Z is the height of any point on the surface of the base arc area from the base plane, and the surface shape of the base arc area 1 meets the formula:

wherein, C1, C2 are the flat K direction of base arc zone, the curvature of steep K direction, namely: C1-1/R1, C2-1/R2. And (r, theta) is a polar coordinate (see fig. 2) of any point on the surface of the base arc area projected to the base plane, wherein the polar coordinate takes the center of the base arc area as the center of a circle and the steep K direction as a polar axis.

Referring to fig. 4, the base arc region 1 has a height z satisfying a sine/cosine distribution state in a circumferential direction of 360 degrees.

The curvature radius R1 of the base arc region 1 in the flat K direction is between 6.00 and 10.50mm, preferably, 7.00 to 10.00mm, and more preferably, 7.50 to 9.50 mm. R2 is between 5.42 and 10.26mm, preferably 6.23 to 9.78mm, and more preferably 6.62 to 9.30 mm.

The diameter of the base arc area in the flat K direction is 4.5-8.0 mm, preferably 5.0-7.0 mm, and more preferably 5.2-6.5 mm.

The height difference between the flat K direction surface shape height and the steep K direction surface shape height of the basal arc area at the diameter of 3.0mm is 10.7-101.8 μm, preferably 10.7-75.8 μm, and more preferably 10.7-50.2 μm.

Under the shaping of the base arc area, the cornea can obtain the astigmatism amount of 0.75-6.00D, and the astigmatism in the eyes is corrected.

The annular curved surface of the adaptive arc area is similar to the base arc area in characteristic and is also an annular curved surface with sine/cosine distribution in height, and the curvature radius of the adaptive arc area in the flat K direction is 6.00-9.50 mm, preferably 6.50-9.00 mm, more preferably 7.00-8.50 mm. The curvature radius in the steep K direction is between 5.42 and 9.43mm, preferably between 5.83 and 8.94mm, and more preferably between 6.23 and 8.45 mm.

An included angle α exists between the flat K direction of the adaptive arc area and the flat K direction of the base arc area, and the included angle is more than or equal to 0 degree and less than or equal to α degree and less than or equal to 180 degree.

< methods for designing and manufacturing orthokeratology mirror >

The method for designing and manufacturing the orthokeratology mirror comprises the following steps:

(1) measuring the size and direction of astigmatism on the anterior surface of the cornea and the whole eye, and calculating the size T and direction of the astigmatism

Such as defining the direction of minimum intraocular power as

The curvature radius design target of flat K of this basic arc district of moulding mirror of cornea, steep K confirms moulding mirror of cornea basic arc district shape, wherein flat K satisfies with the curvature radius R1, the R2 of steep K direction (being equivalent to the utility model provides a "curvature radius parameter of basic arc district"):

wherein, the unit of R1 and R2 is mm, and the unit of T is 'D'.

The measurement range is within 6mm, preferably within 5mm, more preferably within 3mm of the corneal diameter. The measurement method can be the combination of a corneal topography and an objective optometry instrument, or the combination of the corneal topography and an eye-wide aberration measurement device such as iTrace, and other methods for judging the size and the direction of the intraocular astigmatism and the corneal anterior surface astigmatism.

The astigmatism of the anterior surface of the cornea can be obtained through a corneal topography, the size and the direction of the astigmatism of the whole eye can be obtained through other methods or equipment such as an objective refractometer, and the size and the direction of the astigmatism of the eye can be calculated through a vector calculation method:

astigmatism marking of anterior surface of cornea

Wherein T2 represents the magnitude of the corneal anterior surface astigmatism,

an axial direction representing the astigmatism of the anterior surface of the cornea;whole eye astigmatism mark

T3 represents the magnitude of the astigmatism of the whole eye,

axial direction representing astigmatism of the whole eye; intraocular astigmatism marks

T1 represents the magnitude of the intraocular astigmatism,

representing the axial direction of astigmatism in the eye. Intraocular astigmatism

Is astigmatism of whole eye

Astigmatism with the anterior surface of the cornea

The vector difference of (a), namely:

wherein the content of the first and second substances,

the intraocular astigmatism value is determined, and the base arc zone shape of the corneal shaping mirror is further determined. The base curve toric surface provides astigmatism that is similar in magnitude (or substantially the same in magnitude) as the intraocular astigmatism, but in the opposite direction, and serves to compensate (counteract) the intraocular astigmatism.

An example of determining astigmatism in the eye is given below:

a, before wearing, the astigmatism of the whole eye is-5.50 DS-3.00DC × 180, namely, the myopia degree is-5.50D, the astigmatism degree is-3.00D, and the astigmatism direction is 180 degrees.

b anterior corneal surface measurements before wear: 43.25D @180, 46.75D @90, i.e., flat K value of 43.25D orientation 180 and steep K value of 46.75D orientation 90.

c anterior corneal surface astigmatism is: 43.25-46.75 ═ 3.50D, direction 180 °.

The intraocular astigmatism is the astigmatism of the whole eye, namely the corneal astigmatism (-3.00 × 180) - (-3.50 × 180) - (-0.50 × 180).

(2) For example, according to a corneal topography, the shape of the region where the corneal adaptation arc zone is located (the corneal region where the adaptation arc zone is located) is measured, and the curvature radius of the flat K direction and the curvature radius of the steep K direction of the adaptation arc zone are determined, so that the surface shape of the adaptation arc zone of the orthokeratology mirror is determined. Recording the direction of flat K of the adaptive arc zone as

(the direction of the fitting arc zone, flat K, is the direction of the corneal flat K, and also serves as the direction of corneal astigmatism

Is equivalent to the direction parameter of the annular curved surface of the adaptive arc area in the utility model).

(3) According to the magnitude and direction of astigmatism in the eye

And the magnitude and direction of corneal astigmatism

Adapted to the flat K direction of the arc zone

Determining the flat K direction of the base arc zone of the orthokeratology mirror

In the direction of K with the adaptive arc region

Angle α, wherein:

base arc region in the direction of plane K

That is, the direction of astigmatism in the eye, the base curve region being in the K direction

Is equivalent to the direction parameter of the annular curved surface of the base arc area.

After the parameters are determined, a orthokeratology lens is produced.

< method for designing radii of curvature R1 and R2 in the flat K and steep K directions of base arc region >

The refractive state of the cornea is largely determined by its radius of curvature. In practical applications, the common conversion relationship between the curvature radius of the cornea and the corneal diopter is as follows:

wherein K is the diopter of the cornea and has a unit of D, R1 is the curvature radius of the front surface of the cornea in the flat K direction and has a unit of mm, and n is the refractive index of the cornea. For example, n may be 1.3375. When n is 1.3375, the above formula is

R1 is determined by the above formula, R2 is determined by R1 and intraocular astigmatism T, and the relationship is as follows:

namely, it is

Examples

Advantageous effects

By adopting the embodiment, the cornea is shaped into the annular curved surface by the base arc area, the front surface of the cornea can form the astigmatism surface after being shaped, the cornea has the optical effect after being shaped, and can provide the specified astigmatism, the astigmatism and the astigmatism in the eye have the same size and the opposite directions, so that the astigmatism in the eye is counteracted, and the vision and the definition of the eye are improved.

The adaptive arc area realizes the stability of the relative position between the corneal shaping mirror and the cornea through the adaptive matching between tears and corneal topography, and the astigmatic included angle between the base arc area and the adaptive arc area is stable, so that the astigmatic shaping direction of the cornea by the base arc area is limited to be stable every night, and the stability of astigmatic correction can be ensured.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A orthokeratology lens having an inner surface that faces a cornea of a human eye when worn, the inner surface including a centrally located base curve region, the base curve region having a toric shape,

the base zone is configured to provide a prescribed astigmatism to the cornea shaped by the base zone, the prescribed astigmatism being capable of compensating for intraocular astigmatism.

2. The orthokeratology mirror of claim 1, wherein the base arc zone extends in a circumferential direction in a sine curve or a cosine curve.

3. The orthokeratology mirror of claim 1, wherein the inner surface further comprises a mating arc zone on a peripheral side of the base arc zone, the mating arc zone having an toric shape.

4. The orthokeratology mirror of claim 3, wherein the toric shape of the base arc and the toric shape of the mating arc have an angle α between them, 0 ° - α ° -180 °.

5. The orthokeratology mirror of claim 1, wherein for the base arc zone, the direction with the largest radius of curvature is called the flat K direction, the radius of curvature is called R1, the direction with the smallest radius of curvature is called the steep K direction, the radius of curvature is called R2, wherein the R1 and the R2 are perpendicular to each other, a three-dimensional coordinate system is established with the base arc center of the orthokeratology mirror as the vertex, wherein the optical axis direction of the orthokeratology mirror is the Z axis, the plane passing through the base arc center is the base plane, Z is the height from the base plane of any point on the base arc surface, and the base arc zone surface shape satisfies the following formula:

6. The orthokeratology mirror of claim 5, wherein the base arc zone has a flat K-direction radius of curvature R1 of 6.00-10.50 mm, 7.00-10.00 mm, or 7.50-9.50 mm, and a steep K-direction radius of curvature R2 of 5.42-10.26 mm, 6.23-9.78 mm, or 6.62-9.30 mm.

7. The orthokeratology mirror of claim 5, wherein the base arc zone has a flat-K diameter of 4.5-8.0 mm, 5.0-7.0 mm, or 5.2-6.5 mm.

8. The orthokeratology mirror of claim 5, wherein the base arc zone has a height difference between a flat K profile height and a steep K profile height at a diameter of 3.0mm of 10.7-101.8 μm, 10.7-75.8 μm, or 10.7-50.2 μm.

9. The orthokeratology mirror of claim 3 or 4, wherein the radius of curvature of the adaptive arc region in the flat K direction is 6.00-9.50 mm, 6.50-9.00 mm or 7.00-8.50 mm, and the radius of curvature in the steep K direction is 5.42-9.43 mm, 5.83-8.94 mm or 6.23-8.45 mm.