CN204964916U

CN204964916U - Orthokeratology

Info

Publication number: CN204964916U
Application number: CN201520543778.7U
Authority: CN
Inventors: 王曌; 解江冰
Original assignee: EYEBRIGHT (BEIJING) MEDICAL TECHNOLOGY Co Ltd
Current assignee: Abbott (Beijing) Medical Technology Co., Ltd.
Priority date: 2015-07-24
Filing date: 2015-07-24
Publication date: 2016-01-13
Anticipated expiration: 2025-07-24

Abstract

The utility model aims at disclosing an orthokeratology, the ji huqu of lens is the aspheric surface, the aspheric surface is lens base arc and distinguishes the absolute value that peripheral equivalent curvature radius's absolute value is less than the curvature radius of lens base arc district center, compared with the prior art, utilizing aspheric surface control lens ji huqu's shape of face and curvature radius, making its equivalent curvature radius absolute value at the periphery littleer than the center, peripheral shape of face is more precipitous than the sphere, through wearing of a whole night, moulds the shape into orthokeratology jihuqu with people's cornea front surface to the eye of behaving provides the degree controllable myopia out of focus, prevents that the axis oculi from increasing, delays myopia and deepens, realizes the utility model aims at providin.

Description

A kind of Ortho-K

Technical field

The utility model relates to a kind of eyesight correcting glasses, and particularly a kind of periphery out of focus that utilizes is aspheric Ortho-K to control the Ji Huqu of myopia progression.

Background technology

Out of focus (Defocus, out-of-focus) is the corresponding word focusing on (focus), and out of focus refers to image planes not in focus, is divided into front out of focus (before Jiao) and rear out of focus (defocused) two states.

The main cause that the myopia number of degrees increase is that axiallength extends, and often extends 1mm and increases the number of degrees 3.00 degree.Up-to-date medical research confirms, eyeball extends dependence retina (as shown at 10 in figure 1) periphery out of focus, according to anaclastics concept, focus drops on person before retina and is called Myopia out of focus (as shown in Fig. 1 30), drops on person after retina and is called long sight out of focus (as shown in Fig. 1 20).Bathomorphic retinal centre is Myopia out of focus, and retinal periphery is long sight out of focus, and this retinal periphery long sight out of focus promotes the ever-increasing main cause of the myopia number of degrees.

Eyeball has the advantages that to rely on retinal periphery imaging induction eyeball development, especially under-18s juvenile shortsightedness, if retinal periphery is imaged as long sight out of focus, retina can tend to grow to picture point, bulbous length just will extend, if retinal periphery is imaged as Myopia out of focus, stopping just extending by eyeball.If by modern medical service method, correct retinal periphery long sight out of focus or artificial formation retinal periphery Myopia out of focus, just can stop the continuous increase of the myopia number of degrees, find out simultaneously and cause retinal peripheral defocusing reason, can also effectively prevent bathomorphic generation and progress.

Ortho-K adopts " reversion geometry " design concept, whole eyeglass is designed to several mutual segmental arc be connected with the face (inside surface) of Corneal Contact, the special shape wearing rear lens inside surface causes clipping one deck tear pockety between eyeglass and outer corneal surface, and the epithelial cell of Central corneal draws to middle perimembranous (periphery) by the fluid mechanics effect of tear; Meanwhile, during eye closing, the effect of eyelid makes eyeglass central authorities impose certain pressure to inferior cornea.These two kinds of effects cause Central corneal curvature to flatten, and cornea shape is tending towards the shape of Ortho-K inside surface Ji Huqu, and after plucking mirror, human eye refractive status changes, and move, myopia correction depending on thing imaging point near retina direction.

" reversion geometry " design of Ortho-K proposed (US4952045) by Stoyan in 1989, Ortho-K is divided into three Ge Hu districts by initial reversion geometry designs, comprise Ji Huqu, reversion arc district and circumference arc district, because the reversion arc district of this design is very wide, edge tilts highly larger, the random movement of easy initiation eyeglass, has larger limitation clinically.

The Ortho-K that modern " reversion geometry " designs improves reversion geometric areas, is generally divided into four regions.As shown in Figure 2, Ji Hu district 11 contacts cornea middle section, and face shape is comparatively smooth, for flattening anterior corneal surface; Reversion arc district 12 is comparatively precipitous, for the pressing effect in firm Ji Hu district 11, and ensures certain tear storage capacity; Pei Shihu district is named again in arc district 13, location, is mainly used in stabilized lenses; Circumference arc district 14 ensures the circulation of cornea and Ortho-K periphery tear.

The inside surface of Ortho-K is moulding functional realiey region, and most design is carried out for this region, and method is radius-of-curvature for four Ge Hu districts and width Two Variables, designs respectively according to patient's cornea shape and dioptric requirement.

At present, the design being widely used in producing generally adopts 4-7 circular arc dovetail that is individual or 5-7 different curvature radius to form.As shown in Figure 2, four arc districts are the most basic designs, and four Ge Hu districts adopt the sphere of four different radius-of-curvature, and in Ge Hu district, joining place carries out chamfering, makes each segmental arc natural sparse model.5-7 circular arc dovetail refers to that (arc district uses two circular arcs as reversion at the multiple circular arc in reversion arc district 12 and arc district 13, location, arc district, location uses three circular arcs), be connected easier with Shi Jihu district 11 with reversion arc district 12, and arc district, location 13 and cornea shape are more agreed with (because cornea is aspheric surface, adopting multiple sphere to carry out the form of fitting aspherical).Also the design adopting aspheric surface location arc is had in existing design.

Due to the activity of keratocyte, the change of the cornea shape that Ortho-K brings is temporary transient, after stopping wearing Ortho-K, cornea can get back to original form, and therefore initial Ortho-K is only considered a kind for the treatment of means for temporary transient myopia correction.But follow-up clinical research for many years finds, wearing Ortho-K can make a part of teenager's axis oculi growth rate slow down, and then control action is played to myopia progression, clinical research is pointed to, and after wearing Ortho-K, human eye forms the periphery out of focus of myopiaization is the mechanism that Ortho-K works.

The cornea of normal eye is generally aspheric surface, and periphery is more smooth than center, and after cornea is moulding, anterior surface of cornea becomes sphere, i.e. the shape of Ortho-K rear surface.The refractive power (as shown in B in figure) of the sphere cornea (as shown in A in figure) that Fig. 3 is same curvature radius and aspheric cornea is with the schematic diagram of varying aperture, visible, sphere cornea compared with aspheric cornea, can for people near the eyes sideband carry out larger refractive power.Therefore, the real mechanism that Ortho-K controls myopia growth is by wearing eyeglass night, cornea has been fashioned into sphere (shape of Ortho-K Optical Region inside surface) by Ortho-K, thus make the refractive power of human eye periphery when looking thing than larger before moulding, part wearer is made to form myopiaization periphery out of focus, and then slow down axis oculi growth, control myopia progression.

Existing Ortho-K Ji Huqu is sphere, anterior surface of cornea can be modelled as sphere by the Ji Huqu of sphere, the power profile that cornea is provided meets spheroid character, its shortcoming is, for different patient, amphiblestroid degree of crook is different, the outside surface of cornea is modelled as the spherical shape of its Ji Huqu by existing Ortho-K, its power profile only observes the power profile rule of this sphere, namely, for identical moulding rear anterior surface of cornea radius-of-curvature, its power profile only has a kind of form.Such as, be the cornea of 42.25D for moulding rear corneal curvature radius, its power profile can only be a kind of situation as shown in A in Fig. 3, when the flexibility of human eye retina is greater than the power profile flexibility of illustrated cornea formation, Myopia periphery out of focus cannot be formed, and then the object controlling myopia and increase cannot be played.Therefore, base arc be the Ortho-K of sphere cannot be formed degree controlled, effective peripheral refraction power controls, some patients therefore only can be made to be benefited control myopia to increase, and cannot accomplish to make every patient all realize effective control of myopia.

Existing Ortho-K also has some to adopt aspheric design, if Berke is in US7984988B2, the Ji Huqu of Ortho-K is designed to elliptical area; SamiG.EIHage advises, according to cornea shape and tear thickness, determining key coordinate point, carrying out aspheric surface matching by coordinate points in US5695509, determines Ortho-K inside surface face shape; The front surface design of Ortho-K is aspheric surface by patent 201420052256.2, for making human eye wear the interference of rear night from spherical aberration, improves visual quality.The target of these designs is all enable cornea reach more outstanding visual quality at moulding rear human eye, full eye ametropia force is distributed be consistent in each aperture as far as possible, and then causing the periphery out of focus of long sight, this and periphery out of focus control near-sighted object and method all runs in the opposite direction.

Therefore, a kind of Ji Huqu of special needs is special aspheric Ortho-K, and the myopia periphery out of focus that realization degree is controlled, to solve above-mentioned existing Problems existing.

Utility model content

The purpose of this utility model is to provide a kind of Ortho-K, for the deficiencies in the prior art, aspheric surface is utilized to control face shape and the radius-of-curvature in lens optical district, make it less than center at the equivalent radius-of-curvature absolute value of periphery, peripheral surface shape is more precipitous than sphere, thus makes it in radial direction by set power profile mode even variation, eyeglass refractive power increases with aperture and increases, for the myopia out of focus that human eye provides degree controlled, prevent axis oculi from increasing, retarding myopia is deepened.

The technical matters that the utility model solves can realize by the following technical solutions:

A kind of Ortho-K, it comprises eyeglass, and the Ji Huqu of described eyeglass is aspheric surface, and described aspheric surface is the absolute value that the absolute value of the equivalent radius-of-curvature of eyeglass Ji Hu district periphery is less than the radius-of-curvature of eyeglass base arc district center.

In an embodiment of the present utility model, the aspheric expression formula of described eyeglass Ji Huqu is:

Wherein, c is the inverse of basis, optics portion sphere surface curvature radius, and y is that on described curve, any point is apart from the vertical range of abscissa axis (Z), and Q is aspheric coefficient, A _2ifor aspheric surface high-order term coefficient, and described aspheric surface is obtained by carrying out Rotational Symmetry change around abscissa axis (Z) by described aspheric curve.

In an embodiment of the present utility model, aspheric the shape of described eyeglass Ji Huqu is limited by the scale factor η of equivalent radius-of-curvature, the scale factor η < 1 of described aspheric equivalent radius-of-curvature;

Scale factor η is eyeglass different-diameter d _m, d _nunder the ratio of r, m > n, then have:

The computing method of the equivalent radius-of-curvature of described eyeglass Ji Huqu are as follows:

Wherein, wherein d _mfor measuring aperture, M is aperture d _mthe point at place, h _mfor the rise of M point, i.e. the difference in height of aspheric surface between M point and summit, r _mfor the equivalent radius-of-curvature of M point.

Further, preferably, the scale factor η of the equivalent radius-of-curvature of the face shape of aspheric surface under 5mm aperture and 3mm aperture of described eyeglass Ji Huqu is 0.67≤η ₅₃< 1.

Further, preferably, the scale factor η of the equivalent radius-of-curvature of the face shape of aspheric surface under 5mm aperture and 3mm aperture of described eyeglass Ji Huqu is 0.67≤η ₅₃≤ 0.998.

Further, preferably, the scale factor η of the equivalent radius-of-curvature of the face shape of aspheric surface under 5mm aperture and 3mm aperture of described eyeglass Ji Huqu is 0.67≤η ₅₃≤ 0.991.

Ortho-K of the present utility model, compared with prior art, utilize aspheric surface to control face shape and the radius-of-curvature of eyeglass Ji Huqu, make it less than center at the equivalent radius-of-curvature absolute value of periphery, peripheral surface shape is more precipitous than sphere, by wearing of a whole night, eye cornea front surface is modelled as the shape of Ortho-K Ji Huqu, thus the myopia out of focus providing degree controlled for human eye, prevent axis oculi from increasing, retarding myopia is deepened, and realizes the purpose of this utility model.

The detailed description and obtaining that feature of the present utility model can consult the graphic and following better embodiment of this case is well understood to.

Accompanying drawing explanation

Fig. 1 is the schematic diagram of retina, Myopia out of focus and long sight out of focus;

The schematic diagram of longitudinal center's section of the existing Ortho-K of Fig. 2 to be inside surface be four arc districts design;

Fig. 3 is the schematic diagram that the sphere cornea of existing refractive power 42.25D and asphericity coefficient Q value are-0.25, refractive power is the power profile situation of aspheric cornea under different pore size of 42.25D;

Fig. 4 is the structural representation of Ortho-K of the present utility model;

Fig. 5 is aspheric surface and the curve synoptic diagram of basic sphere in YZ plane of Ortho-K Ji Huqu of the present utility model;

Fig. 6 is the schematic diagram that scale factor η of the present utility model relates to parameter.

Embodiment

The technological means realized to make the utility model, creation characteristic, reaching object and effect is easy to understand, below in conjunction with concrete diagram, setting forth the utility model further.

Term definition:

The term " Optical Region " used in this application refers to and is positioned at having optical characteristics thus can realizing regulating the part of eyeglass dioptric major function of center of lens region.

The term " radial direction " used in this application refers to the rectilinear direction from center of lens along radius or diameter.

The term " aperture " used in this application refers to the diameter of lens surface radial direction.

In this application use and represent that the term such as "front", "rear" of position relation is for the distance on cornea eye surface.Such as, for the eyeglass of the application, " rear surface, optics portion " is the optical surface nearer than " anterior optic surface " distance cornea eye.

The term " basic sphere " used in this application refers to the ideal spherical face with same curvature radial design value corresponding with various the shapes that the forward and backward surface in the optics portion of eyeglass adopts.In this application, in order to unified term, be called unified for this ideal spherical face " basic sphere ".

The term " precipitous " used in this application and " smooth " refer to the description of the equivalent radius-of-curvature size degree to lens, such as, for the application, " more precipitous than sphere " refers to the radius-of-curvature absolute value of the absolute value comparative basis sphere of the equivalent radius-of-curvature of eyeglass and Yan Geng little, and " more smooth than sphere " refers to the radius-of-curvature absolute value of the equivalent radius-of-curvature absolute value comparative basis sphere of eyeglass and Yan Geng great.

As shown in Figure 4, Ortho-K of the present utility model, it comprises eyeglass 100, the Ji Hu district 101 (with the Optical Region in the face of Corneal Contact) of eyeglass 100 is aspheric surface, and described aspheric surface is the absolute value that the absolute value of the equivalent radius-of-curvature of Ji Hu district 101 periphery of eyeglass 100 is less than the radius-of-curvature at the center, Ji Hu district 101 of eyeglass 100.

As shown in Figure 5, the aspheric expression formula in the Ji Hu district 101 of eyeglass 100 is:

As shown in Figure 6, aspheric the shape in the Ji Hu district 101 of eyeglass 100 is limited by the scale factor η of equivalent radius-of-curvature, the scale factor η < 1 of described aspheric equivalent radius-of-curvature;

For sphere, then η=1; For the aspheric surface of periphery than central flat, then η > 1; For the aspheric surface that periphery is more precipitous than center, then η < 1.

Aspheric radius-of-curvature can not represent by the radius-of-curvature of traditional sphere, but by equivalent radius-of-curvature.The computing method of the equivalent radius-of-curvature in the Ji Hu district 101 of eyeglass 100 are as follows:

Preferably, the scale factor η of the equivalent radius-of-curvature of the face shape of aspheric surface under 5mm aperture and 3mm aperture in the Ji Hu district 101 of described eyeglass 100 is 0.67≤η ₅₃< 1.

More preferably, the scale factor η of the equivalent radius-of-curvature of the face shape of aspheric surface under 5mm aperture and 3mm aperture in the Ji Hu district 101 of described eyeglass 100 is 0.67≤η ₅₃≤ 0.998.

More preferably, the scale factor η of the equivalent radius-of-curvature of the face shape of aspheric surface under 5mm aperture and 3mm aperture in the Ji Hu district 101 of described eyeglass 100 is 0.67≤η ₅₃≤ 0.991.

The specific embodiment that the utility model relates to is see table 1 and table 2, and in table, Q, A4, A6, A8 are asphericity coefficient; η ₅₃for the scale factor of the equivalent radius-of-curvature of eyeglass under 5mm aperture and 3mm aperture

Face, table 1 Ortho-K Ji Hu district shape embodiment

Radius-of-curvature	Q	η ₅₃	Radius-of-curvature	Q	η ₅₃
						9.643	0.2	0.998	5.000	2.5	0.820
9.643	0.5	0.994	10.000	5.0	0.940
						9.643	1.0	0.989	7.000	0.5	0.989
6.136	0.2	0.994	7.000	3.0	0.921
						6.136	1.0	0.969	8.000	3.0	0.944
6.136	3.0	0.885	5.000	0.2	0.991
						6.136	5.0	0.665	5.000	0.5	0.976
6.136	4.0	0.818	5.000	0.7	0.966
						5.000	1.0	0.949	5.000	2.0	0.876
5.000	1.2	0.937	5.000	2.5	0.820
						5.000	1.5	0.917	5.000	2.9	0.741

Face, table 2 Ortho-K Ji Hu district shape embodiment

Radius-of-curvature	Q	A4	A6	A8	η ₅₃
						5.946	9.400E-02	1.604E-04	1.695E-06	2.829E-07	0.990
4.935	1.385E-01	4.806E-04	4.146E-06	9.006E-07	0.978
						4.934	1.385E-01	4.702E-04	4.087E-06	8.892E-07	0.978
4.939	1.618E-01	6.567E-04	1.322E-05	8.648E-07	0.970
						5.068	8.048E-03	6.610E-05	6.408E-07	2.590E-09	0.997

Those skilled in the art will readily appreciate that, different asphericity coefficient combinations can be adopted to realize the non-spherical structure identical with the utility model.

Under the aspheric design thinking that the utility model Myopia periphery out of focus controls myopia growth and eyeglass, those skilled in the art also can expect, the eyeglass Ji Huqu Deformation control contrary with the utility model can be passed through, equivalent radius-of-curvature absolute value under making the equivalent radius-of-curvature absolute value of eyeglass under large aperture be greater than small-bore, human eye is made to reach long sight periphery out of focus, thus by initiatively promoting that axis oculi increases, treatment long sight.

More than show and describe ultimate principle of the present utility model and principal character and advantage of the present utility model.The technician of the industry should understand; the utility model is not restricted to the described embodiments; what describe in above-described embodiment and instructions just illustrates principle of the present utility model; under the prerequisite not departing from the utility model spirit and scope; the utility model also has various changes and modifications; these changes and improvements all fall within the scope of claimed the utility model, and the claimed scope of the utility model is defined by appending claims and equivalent thereof.

Claims

1. an Ortho-K, it comprises eyeglass, it is characterized in that, the Ji Huqu of described eyeglass is aspheric surface, and described aspheric surface is the absolute value that the absolute value of the equivalent radius-of-curvature of eyeglass Ji Hu district periphery is less than the radius-of-curvature of eyeglass base arc district center.

2. Ortho-K as claimed in claim 1, it is characterized in that, the aspheric expression formula of described eyeglass Ji Huqu is:

Wherein, c is the inverse of basis, optics portion sphere surface curvature radius, y is the vertical range of any point distance abscissa axis (Z) on curve, Q is aspheric coefficient, A2i is aspheric surface high-order term coefficient, and aspheric surface is obtained by carrying out Rotational Symmetry change around abscissa axis (Z) by aspheric curve.

3. Ortho-K as claimed in claim 1, it is characterized in that, aspheric the shape of described eyeglass Ji Huqu is limited by the scale factor η of equivalent radius-of-curvature, the scale factor η < 1 of described aspheric equivalent radius-of-curvature;

Scale factor η is the ratio of the r under eyeglass different-diameter dm, dn, and m > n, then have:

；

，

Wherein, wherein dm is for measuring aperture, and M is the point at dm place, aperture, and hm is the rise of M point, i.e. the difference in height of aspheric surface between M point and summit, and rm is the equivalent radius-of-curvature of M point.

4. Ortho-K as claimed in claim 3, it is characterized in that, preferably, the scale factor η of the equivalent radius-of-curvature of the face shape of aspheric surface under 5mm aperture and 3mm aperture of described eyeglass Ji Huqu is 0.67≤η 53 < 1.

5. Ortho-K as claimed in claim 3, it is characterized in that, preferably, the scale factor η of the equivalent radius-of-curvature of the face shape of aspheric surface under 5mm aperture and 3mm aperture of described eyeglass Ji Huqu is 0.67≤η 53≤0.998.

6. Ortho-K as claimed in claim 3, it is characterized in that, preferably, the scale factor η of the equivalent radius-of-curvature of the face shape of aspheric surface under 5mm aperture and 3mm aperture of described eyeglass Ji Huqu is 0.67≤η 53≤0.991.