CN109581690B

CN109581690B - Lens, glasses and method for acquiring defocus parameter, fitting and evaluating effect

Info

Publication number: CN109581690B
Application number: CN201811592602.5A
Authority: CN
Inventors: 魏瑞华; 王景慧; 杜蓓; 林伟平; 谷天瀑; 刘桂华
Original assignee: TIANJIN MEDICAL UNIVERSITY EYE HOSPITAL
Current assignee: TIANJIN MEDICAL UNIVERSITY EYE HOSPITAL
Priority date: 2018-12-25
Filing date: 2018-12-25
Publication date: 2020-07-03
Anticipated expiration: 2038-12-25
Also published as: CN111708183B; CN109581690A; CN111897141A; CN111897141B; CN111708183A

Abstract

The peripheral defocused lens comprises a central optical area, an annular defocused area is arranged outside the central optical area, and the defocused amount of the defocused area changes in the annular direction. At least one of the base arc zone and the reversal arc zone of the orthokeratology lens provided by the application has structural change in the circumferential direction. The method for acquiring the defocus quantity parameter comprises the following steps: collecting defocus amounts of a plurality of sampling points on a user cornea or a dioptric system consisting of a cornea and a lens of a myope, wherein the sampling points are distributed on a plurality of direction angles in a coordinate system taking the center of the cornea as an origin; and obtaining the defocus parameter according to the defocus of the plurality of sample points on the cornea. The application also provides a method for determining the myopia control effect of the orthokeratology lens on the myope according to the defocus quantity parameter.

Description

Lens, glasses and method for acquiring defocus parameter, fitting and evaluating effect

Technical Field

The application relates to the field of myopia prevention and control, in particular to a lens, glasses, a method for acquiring a defocus parameter, a glasses fitting method and a method for evaluating a myopia control effect.

Background

Myopia has become a major public health problem and a significant burden on society. The degree of deflection of the light at the interface can be expressed by the refractive power. The optical power depends on the refractive indices of the two media and the radius of curvature of the interface. Myopia is one of the refractive errors. For a normal eyeball, both central and peripheral images are projected on the retina. In a myopic eye, due to the elongation of the eyeball, parallel rays are refracted by a dioptric system of the eye in a relaxed state, and then the focal point falls in front of the retina.

The mechanism of progression of myopia is still under intense discussion and many means of controlling the growth of the ocular axis have been discovered including different concentrations of drugs and different optical designs of lenses. The peripheral defocus theory is a cause of myopia proposed by professor Smith at the eye vision academy of houston university, usa, at the end of the last century. According to the concept of dioptric power, the focus falling in front of the retina is called myopic defocus and the focus falling behind the retina is called hyperopic defocus. The peripheral defocus theory considers that this hyperopic defocus at the periphery of the retina is the main cause of the increasing number of myopic eyes. The myopic defocus around the retina can slow down the increase of the axis of the eye, and has the effect of inhibiting the development of myopia.

The primary purpose of conventional single vision spectacles is to address the need for the wearer to be blinded and to correct for defocus in the central macular area of the eye. FIG. 1 is a schematic view of an eye corrected with a single vision lens. The object image at the central vision is projected on the retina, and the object image at the peripheral area is projected behind the retina to form hyperopic defocus. The eye adjusts to project an object image of the peripheral region onto the retina, which causes the axis of the eye to slowly elongate. Therefore, after some patients wear ordinary spectacles, although the problem of unclear seeing is solved, the degree of myopia is continuously deepened.

The peripheral defocused novel lens can reduce the hyperopic defocusing of the periphery of the retina and even change the peripheral defocusing into the myopic defocusing so as to relieve the increase of the axis of the eye. Such specially designed optical lenses may be lenses of OrthoKeratology lenses (e.g., OK lenses), contact lenses (including soft contact lenses, hard contact lenses such as RGP lenses, etc.), or frame lenses (e.g., prismatic two-frame lenses, progressive addition lenses, etc.). After the myopic eye is corrected by the peripheral defocused lens, the object image at the central vision part is projected onto the retina, and the peripheral object image is projected onto the retina or in front of the retina, so that the myopic defocused effect is formed, as shown in fig. 2. Researches find that the success rate of controlling myopia (namely inhibiting the growth speed of an eye axis) by the corneal contact lens out of focus at the periphery can reach about 30-40%.

The orthokeratology lens adopts an inverse geometric design, achieves the purposes of correcting eyesight and controlling myopia development by changing the shape of the cornea, and the success rate of controlling myopia development can reach 32-55%. Different from frame glasses and corneal contact lenses, the corneal shaping lens only needs to be worn at night, and can reach a normal value without wearing vision in the daytime. The design of the orthokeratology lens is divided into a VCT (vision reshaping treatment) design and a CRT (corneal regenerative thermal corneal refractive correction) design. The cornea shaping mirror designed by VST comprises a basal arc area, a reversal arc area, a positioning arc area and a peripheral arc area.

The central portion of the lenses of both contact lenses and spectacle frames is typically a central optic zone of constant power, for the peripheral defocus lenses used in this application for myopia control, where the peripheral zone outside the central optic zone has a higher power than the central optic zone, the difference in power between the two is expressed in defocus and is in D (degrees). For example, if the power of the central optical zone of a lens for near vision is-2.00D (which is typically the power of the lens), and the peripheral position has a defocus amount of 4.5D, then the power of the peripheral position of the lens is 2.5D. If the power of the central optical zone of the lens for near vision is-5.00D and the defocus amount at the peripheral position is still 4.5D, the power at the peripheral position of the lens is-0.50D.

The defocus design of the peripheral defocus lens is related to the effect of myopia control, but which defocus parameters are related to myopia control (meaning control of myopia progression) and the mechanism of the correlation between defocus parameters and myopia control is not clear, so that the design and fitting of the peripheral defocus lens are difficult to perform in a targeted manner, which affects the effect of myopia control that can be achieved by the peripheral defocus lens.

For orthokeratology, there is currently only an estimate of the amount of defocus that it creates on the cornea. No other defocus parameters associated with myopia control are proposed. Moreover, clinical estimates of the effectiveness of orthokeratology lenses are still lacking in standards, and it takes a long time to be able to determine the effectiveness of myopia control for a particular myope. This affects the application of the corneal mirror shape.

Disclosure of Invention

The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

The embodiment of the invention provides a peripheral defocused lens, which comprises a central optical area, wherein an annular defocused area is arranged outside the central optical area, and the defocused amount of the defocused area varies in the circumferential direction.

The invention embodiment provides frame glasses, which comprise a frame and two lenses, and is characterized in that at least one of the two lenses adopts the lens with the out-of-focus periphery as described above.

The embodiment of the invention provides a lens of a corneal shaping mirror, which comprises a base arc area, an inversion arc area and a positioning arc area, wherein at least one of the base arc area and the inversion arc area has structural change in the circumferential direction.

The embodiment of the invention provides a method for acquiring a defocus amount parameter, which comprises the following steps: in a naked eye state of a user, acquiring defocus amounts of a plurality of sampling points on a cornea of the user, wherein the sampling points are distributed on a plurality of direction angles in a coordinate system taking the center of the cornea as an origin; and obtaining defocus parameters according to the defocus of the plurality of sample points on the cornea.

The embodiment of the invention provides a method for acquiring a defocus amount parameter, which comprises the following steps: when a myope wears a corneal contact lens, acquiring defocus amounts of a plurality of sampling points on a dioptric system consisting of the cornea and a lens of the myope, wherein the sampling points are distributed on a plurality of direction angles in a coordinate system taking the center of the cornea as an origin; and obtaining a defocus parameter according to the defocus of a plurality of sample points on the dioptric system.

The embodiment of the invention provides a lens fitting method, which comprises the following steps: acquiring the defocus parameter of the myope in the naked eye state before fitting the glasses according to the defocus parameter acquiring method; and fitting the glasses for the myope according to the defocus quantity parameter.

The embodiment of the invention provides a method for evaluating the myopia control effect, which comprises the following steps: acquiring defocus parameters obtained by a myope in an naked eye state after the cornea is shaped by a cornea shaping mirror according to the method; and determining the myopia control effect of the corneal shaping mirror on the myope according to the defocus quantity parameter.

Other aspects will be apparent upon reading and understanding the attached drawings and detailed description.

Drawings

FIG. 1 is a schematic illustration of a hyperopic defocus produced when correcting myopia using a single vision lens;

FIG. 2 is a schematic illustration of myopic defocus generated using peripheral defocus lenses;

FIG. 3A is a schematic diagram of defocus as a function of distance for a patient's cornea in the same azimuthal direction;

FIG. 3B is a schematic diagram of the change in mRCRP of a patient's cornea over a range of 0-360 degrees;

FIG. 4 is a schematic diagram of components in the built mRCRP model;

FIG. 5 is a schematic diagram of the relationship between the maximum defocus Vmax and the eye axis growth length;

FIG. 6 is a graph showing myopia control success as Vmax varies;

FIGS. 7A-7D are schematic diagrams of several different scenarios for component values in the mRCRP model;

FIGS. 8A and 8B are schematic diagrams of peripheral out-of-focus lenses of two exemplary embodiments of the invention;

FIG. 9 is a schematic view of a orthokeratology lens in accordance with an exemplary embodiment of the present invention;

FIG. 10 is a cross-sectional view A-A of FIG. 9;

FIG. 11 is a flowchart of a method of obtaining defocus parameters in an exemplary embodiment of the invention;

FIG. 12 is a flowchart of another method of obtaining defocus parameters in an exemplary embodiment of the invention;

FIG. 13 is a flow chart of a method of providing prescription in accordance with an exemplary embodiment of the present invention;

FIG. 14 is a flow chart of a method of evaluating the effectiveness of myopia control according to an exemplary embodiment of the present invention;

FIG. 15 is a schematic diagram of a computer device of an exemplary embodiment of the present invention.

Detailed Description

The present application describes embodiments, but the description is illustrative rather than limiting and it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the embodiments described herein. Although many possible combinations of features are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are possible. Any feature or element of any embodiment may be used in combination with or instead of any other feature or element in any other embodiment, unless expressly limited otherwise.

The present application includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The embodiments, features and elements disclosed in this application may also be combined with any conventional features or elements to form a unique inventive concept as defined by the claims. Any feature or element of any embodiment may also be combined with features or elements from other inventive aspects to form yet another unique inventive aspect, as defined by the claims. Thus, it should be understood that any of the features shown and/or discussed in this application may be implemented alone or in any suitable combination. Accordingly, the embodiments are not limited except as by the appended claims and their equivalents. Furthermore, various modifications and changes may be made within the scope of the appended claims.

Further, in describing representative embodiments, the specification may have presented the method and/or process as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. Other orders of steps are possible as will be understood by those of ordinary skill in the art. Therefore, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. Further, the claims directed to the method and/or process should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the embodiments of the present application.

In the present application, both orthokeratology and contact lenses may be made of gas permeable Rigid material (RGP), but fall into two different types of lenses. The orthokeratology lens adopts a lens designed by inverse geometrical shape, and the inner surface of the orthokeratology lens consists of a plurality of arc sections. The cornea geometric form is changed through the hydrodynamic effect, the pillow is worn on the front part of the cornea during sleep, the corneal curvature is gradually flattened, the eye axis is shortened, and the pillow does not need to be worn in the daytime. Contact lenses, which are also called contact lenses (contact lenses), are not designed in inverse geometry, and correct vision or protect eyes by optical effects generated by wearing on the cornea of an eyeball, and can include three types of materials, namely hard, semi-hard and soft. The lenses of the frame glasses are arranged on the glasses frame, and the distance exists between the lenses and the eyeballs.

One of the criteria for successful fitting of orthokeratology lenses is the creation of a centered central location, i.e., a uniform peripheral defocus on the cornea. Research shows that the larger the myopic ametropia, the larger the peripheral defocus amount formed, and the relatively good myopia control effect. However, the specific size is not mentioned as to which parameter the defocus amount is estimated, and the size of the peripheral defocus amount is also limited in various ways, and cannot be made particularly large. The data range of peripheral defocus selected by the research of the conclusion is large and is-1.00 to-6.00D. Meanwhile, the research conclusion is contrary, the magnitude of the peripheral defocus amount and the myopia control effect are not necessarily related, and the peripheral defocus data range generally selected according to the research is small. In addition, in the case of contact lenses and spectacle lenses, if a lens with an excessive peripheral defocus amount is used, the patient feels uncomfortable, the vision and contrast sensitivity are reduced, and the manufacturing is difficult. The peripheral defocusing design scheme adopted by the lenses of the current corneal contact lenses and frame glasses has the myopia control effect lower than that of a corneal plastic lens.

If the mechanism of the orthokeratology lens for relieving the eye axis growth can be better explained, the clinical fitting of the orthokeratology lens has great guiding significance, and meanwhile, the mechanism can be popularized to the peripheral defocusing design of contact lens lenses and frame spectacle lenses. Therefore, the inventors of the present application conducted a prospective study to investigate the influence of factors such as the defocus state and degree of the cornea on the growth of the ocular axis of a myopic patient after wearing a keratoplast.

For defocus, only the total amount is estimated or it is assumed that a uniform peripheral defocus condition is formed after the shaping operation. The inventor of the application finds that peripheral defocusing formed on the cornea of a patient wearing the plastic lens is not uniform due to different meridian reactions to defocusing of the retina caused by corneal astigmatism and asphericity of the retina. It is not scientific to use the total or mean value of peripheral defocus to measure the effect of peripheral defocus on myopia control. For myopes of-1.00 to-5.00D, which are frequently seen in clinic, the difference of the total defocus amount of the periphery after the orthokeratology is not large, but the maximum defocus amount on the cornea is caused by the difference of the distribution of the peripheral defocus on the cornea after the orthokeratology (the maximum defocus amount is also called as an extreme value in the application, and the position of the maximum defocus amount on the cornea can be one point or a plurality of points, can be distributed together in a centralized way, and can also be distributed at a plurality of places in a scattered way). The retina is more sensitive to defocus not the total amount, but the extreme value of defocus, i.e. has extreme value sensitivity. The magnitude of the maximum defocus on the cornea is more important than the magnitude of the total defocus amount in terms of the effect of peripheral defocus on myopia control.

The inventor of the application carries out experimental research on the relation between the defocusing amount on the cornea and the myopia control effect after children wear the cornea shaping mirror, and the experimental method is as follows:

55 adolescents aged 8-12 years are used as patients, and the patients have no history of using myopia control products, no eye surface diseases and no systemic diseases affecting dioptric systems. The mydriatic refraction of the patient is less than or equal to-5.50D and less than or equal to-1.00D (SE is equivalent spherical diopter), the corneal astigmatism is less than or equal to-1.50D, the refractive error is less than 1.0D, and the optimal correction vision is higher than 20/20. Patients were subjected to a full-scale examination and then were fitted with a corneal plastic lens (euclidd System crop., Herndon, VA) produced by euclidean corporation, and all patients were reviewed between 2-5 pm; corneal biomechanics was measured before and one year after wear using an optical correlation biometer (Lenstar LS900, Haag-Streit AG, Switzerland), respectively. Corneal topography was examined using a corneal topographer (Oculus, Wetzlar, Germany) before and four months after wear. The right eye data was collected for each patient and all data were normalized using the Charpy-Wilk test (Schapiro-Wilk test). The difference between the ideal and the non-ideal group for myopia control in the model was compared using the rank sum test (Ranksum test) method. And analyzing the relationship between the myopia control success rate and the maximum defocus amount by using a Logistic regression analysis method.

In this experiment, the data obtained from the corneal topography was accurately analyzed to determine the defocus parameter on the cornea using the following method: the positioning of the lens was determined with Matlab software. The cornea is equally divided into 36 fan-shaped areas by taking the center of the cornea as a circle center, the central angle of each area is 10 degrees, and a plurality of sampling points are taken in each area, wherein the sampling points comprise a sampling point at the center of the cornea so as to calculate the defocusing amount of other sampling points. The sampling points can be uniformly distributed in the area, and can also be distributed on 36 direction angles which are sequentially spaced by 10 degrees, and the calculation precision is higher when the sampling points are more. For each area, the defocus of all the sample points in the area can be calculated from the corneal topography, as shown in fig. 3A. The horizontal axis in the figure represents the distance of a point on this region from the center of the cornea (i.e., the radial distance). The vertical axis represents the power of a point on the area. The power at the center of the cornea in the figure is 40 degrees, and the power at other points minus 40 is the defocus at that point. The maximum defocus in the graph represents the defocus of the region and is denoted as mRCRP. mRCRP generally occurs in the corneal region corresponding to the arc of reversal of the orthokeratology mirror.

For each patient, 36 mPPRPRs and their corresponding angles are available for 36 zones, e.g., 0 to 10 for the zone may be set to 0 (or another value from 0 to 10), 10 to 20 for the zone may be set to 10 (or another value from 10 to 20), and so on. A defocus curve, called mPCRP curve, can be obtained by curve fitting the 36 mPCRP curves (i.e., selecting the appropriate curve type to fit the observed data and analyzing the relationship between the two variables using the fitted curve equation), as shown in fig. 3B. The horizontal axis in fig. 3B is the direction angle, the vertical axis is the mPCRP value, and the circle in the graph, i.e. the position of 36 mPCRP in the graph, is the mRCRP curve. The maximum peak of the defocus curve is denoted as Vmax, which is the maximum defocus amount on the cornea after the reshaping, and may be referred to as the maximum defocus amount on the cornea.

For each patient, a model for accurately calculating mPPRP can be established according to the fitted defocus curve: mRCRP ═ M + F1+ F2. Specifically, a multiple linear regression detection model can be adopted, and relevant factors comprise an equivalent sphere lens, lens positioning, astigmatism, corneal eccentricity and the like. R2 ═ 0.93 ± 0.06 (mean 0.94). In statistics, linear regression analysis is carried out on variables, and when a least square method is adopted for parameter estimation, R2 is a ratio of regression sum of squares and total sum of deviations squares, and represents a proportion that the total sum of deviations squares can be explained by the regression sum of squares, and the larger the ratio is, the more accurate the model is, and the more remarkable the regression effect is.

Referring to fig. 4, the model includes three parts: m represents the mean refractive power, this value being related to the initial equivalent spherical lens before the patient wears the orthokeratology lens, represented in the figure as the horizontal dashed line; f1 is a sinusoidal curve, which can be expressed as (Mean F1 sin (x + phase1)), having a peak over a 360 degree angular range, F1AmpF2 being the maximum of F1; f2 is a cosine curve, which can be expressed as (Mean F2 sin (2 x + phase2)), with two peaks over 360 degrees of azimuth, and F2Amp is the maximum of F2. Studies have shown that the magnitude of the F1 amplitude F1 is related to the asymmetry of lens positioning (e.g., wear bias, etc.). Whereas the peak F2 of F2 is associated with corneal astigmatism. The values of the three specific parameters in the model can be obtained by calculation according to the defocus curve. The resulting superposition of the three parts, i.e. the mRCRP curve, is shown by the solid line in the figure. The maximum value is Vmax and the minimum value is Vmin.

After one year of wear, corneal biomechanics were measured for each patient, with 0.3mm as the ocular axis growth threshold for determining whether myopia control was effective. The results showed that 40 out of 55 patients had effective myopia control with a annual increase in the axis of the eye of less than or equal to 0.3mm, 15 patients had unsatisfactory myopia control with an annual increase in the axis of the eye of greater than 0.3 mm. The results of whether the myopia control is successful or not are combined with the mRCRP curve of each patient, and the larger the Vmax on the mRCRP curve of the patient is, the higher the success rate is. As shown in FIG. 5, the horizontal axis represents Vmax, the vertical axis represents the length of the increase of the eye axis, each circle corresponds to one patient, the circles below the 0.3mm line correspond to patients with successful myopia control, and the circles above the 0.3mm line correspond to patients with failed myopia control.

FIG. 6 is a graph of Vmax versus myopia control success rate showing that as Vmax increases, the success rate of myopia control increases (p < 0.05). When Vmax is less than or equal to 1.2D, only 20% of patients succeed; when Vmax is larger than or equal to 3.5D, more than 50% of patients are successful; vmax is more than or equal to 4.5D, and more than 80 percent of patients succeed; when Vmax is more than or equal to 5D, more than 90% of patients are successful. According to the relation, Vmax is adopted for evaluation according to the statistical data, and when the Vmax is less than or equal to 1.2D, the probability that the myopia control is effective is 20 percent; when Vmax is more than or equal to 3.5D, the probability of myopia control is more than 50 percent effective; vmax is more than or equal to 4.5D, and the probability of myopia control is more than 80 percent effective; when Vmax is larger than or equal to 5D, the probability of over 90 percent of near vision control is effective.

The above data are only exemplary, more and wider (for example, myopic children in different countries) tests can be performed according to the analysis method or the similar method provided by the present application, and the data obtained by statistics of the tests do not necessarily have the same specific data such as Vmax and the corresponding relation of myopia control success rate, which is a normal phenomenon.

Taking the threshold value of 4.5D as an example, analyzing the mRCRP curve established for each patient and whether the myopia control is successful or not, it can be found that:

if the value of M is large, although the mRCRP curve does not fluctuate, the defocus amount of each position on the cornea can reach 4.5D, as shown in FIG. 7A, and myopia can be effectively controlled.

If the M value is small and the mRCRP curve fluctuates little, the defocus amount of no point on the cornea can reach 4.5D, as shown in FIG. 7B, and there is no control effect.

If the M value is at the mean value, but the mRCRP curve does not fluctuate much, the defocus amount of no point on the cornea exceeds 4.5, as shown in FIG. 7C, and the control effect is not good.

If M is small but mRCRP fluctuates greatly, the defocus amount of a part of points on the cornea exceeds 4.5D, as shown in FIG. 7D, and the control effect is good.

The model mRCRP established for the patient is M + F1+ F2, where M is related to the degree of myopia. For low to moderate myopia, the value of M will be lower and, according to the model, increases in F1 and F2 will increase Vmax, improving myopia control. Therefore, the applicant proposes a new theory on the influence of peripheral defocus on myopia control: the retina is sensitive to the extreme value of peripheral defocus, the defocus amount at all positions is not required to be the same, and myopia can be effectively controlled as long as the maximum defocus amount Vmax is large enough. And the larger Vmax is, the higher the success rate of myopia control is, and by comparing the Vmax of the patient with a set defocus threshold (such as 3.5D and 4.5D), the myopia control effect can be effectively evaluated. In addition, studies have shown that the success rate of myopia control can be assessed from the defocus threshold as long as a point of the reshaped cornea reaches the defocus threshold. Under the condition of keeping the distance from the threshold value unchanged, if the area (which can be represented by a corresponding central angle) of the cornea with the defocus amount reaching the defocus threshold value is larger, the success rate of the cornea is correspondingly improved.

Although the above studies were conducted with orthokeratology as the source, the established model, and the proposed volatility and threshold of peripheral defocus, are applicable to the design of peripheral defocus lenses. The above theory gives an important hint to lens design: under the condition that the total defocus amount is not changed, Vmax can be increased by carrying out uneven design of peripheral defocus, and myopia control is facilitated. This is of great guidance to lens design, whether for spectacle frames or contact lenses.

In addition, the analysis shows that in the model mRCRP established for the patient M + F1+ F2, the amplitudes of F1 and F2 are also relevant to the myopia control effect, and one or both of F1 and F2 are large, so that the success rate of myopia control is higher. It is readily understood that the maximum peak Vmax of mRCRP is generally larger if the magnitudes of F1 and F2 are large. As can be seen from fig. 4, in the case that the amplitudes of F1 and F2 are not changed, if one peak of F1 and one of the two peaks of F2 are at the same orientation angle and the two peaks can be superimposed, the obtained Vmax is the largest, and the myopia control effect is the best. Conversely, the resulting Vmax will decrease and the myopia control will also decrease. As mentioned before, F1 is associated with lenses to be worn and F2 is associated with corneal astigmatism, this then gives another important insight into lens design and wear: the maximum defocus brought by the lens is aligned with the maximum defocus on the cornea, so that extreme value superposition can be realized, and the myopia control effect can be improved.

To this end, exemplary embodiments of the present invention provide a peripheral through-focus lens, which may be, but need not be, circular. As shown in fig. 8A, the lens 1 includes a central optical zone 11, which is externally provided with an annular defocus zone 12, and the defocus amount of the defocus zone varies circumferentially. In principle, a large amount of defocus is advantageous for controlling the progression of myopia, but if the amount of defocus is too large, discomfort can be caused to the myope, such as dizziness and the like, and adverse effects such as limited visual field, reduced vision and reduced contrast sensitivity can be caused. Through the change of out of focus volume in the hoop, under the unchangeable condition of the maximum out of focus volume, can reduce the out of focus volume in some separation focus areas to when guaranteeing the myopia control effect, alleviate these adverse effects.

In the exemplary embodiment shown in fig. 8A, the central optical zone 11 of the lens 1 is a circular fixed-focus zone, and the lens 1 includes an annular out-of-focus zone centered at the center of the lens (point "O" in the figure). However, the present application is not limited to this, and the lens may also include a plurality of annular out-of-focus areas centered on the center of the lens, as shown in fig. 8B, the lens 1 includes two annular out-of-focus areas 12a,12B, which are exemplarily disposed at intervals between the two out-of-focus areas 12a,12B in the figure, and the middle of the two out-of-focus areas may also be a fixed-focus area with an out-of-focus amount of 0. In other embodiments, more defocus regions may be provided. Among the plurality of defocus regions, only some of the defocus regions may be varied in the circumferential direction, i.e., it falls within the scope of the present application as long as there is one defocus region varied in the circumferential direction.

In FIG. 8A, a 0 ° direction angle is defined to point to the right, and a direction angle of a point P in FIG. 8A is represented as α. the defocus amount in the out-of-focus area varies circumferentially, i.e., the defocus amount in the out-of-focus area varies over a 360 degree direction angle range, in other words, the defocus amount in the out-of-focus area varies over a direction angle from 0 to 360.

When viewed from the radial direction of the lens, when an out-of-focus area exists, the out-of-focus amount can have an ascending and descending change along with the increase of the radial distance. When a plurality of defocus regions exist, there may be a plurality of ascending and descending processes. The defocus amount of the area outside the out-of-focus area may be smaller than the out-of-focus area or equal to 0, or may be equal to or larger than the out-of-focus area, for example, the defocus amount increases with the radial distance. May remain unchanged or continue to increase after the last out-of-focus zone has risen.

In the exemplary embodiment shown in fig. 8A, the lens includes an indicator 13 for indicating a direction angle at a position where the defocus amount is maximum in the out-of-focus region. The position with the largest defocus amount may be a point or an area including a plurality of points, and if there are a plurality of positions with the largest defocus amounts, one position may be selected to be indicated, or each position may be indicated by using an indicator 13. The indicator may be integrally formed with the lens, or attached to the lens, or embedded within the lens. For example, the indicator may be a protrusion or a groove on the lens, or a marker attached to a corresponding location on the lens, or a marker or even an air bubble in the lens. Although the indicator 13 is an upward arrow in the example in fig. 8A, the indicator may be in the shape of a bar, a dot, or any other symbol. The indicator may directly indicate the position where the defocus amount is maximum in the out-of-focus area, and an arrow in the figure is used to indicate that the position where the defocus amount is maximum in the out-of-focus area appears at a 90 ° directional angle. When the position with the largest defocus amount in the out-of-focus area is an area, the direction angle of the center position of the area can be generally indicated, but a deviation is allowed, and the use is not affected. The indication mark can also indicate the position with the largest defocus amount in an indirect manner, such as pointing to the opposite direction thereof, and so on. After the indication mark is arranged on the lens, when a myope wears the lens (especially wears a corneal contact lens), the position with the maximum defocus amount of the lens is aligned with the position with the maximum defocus amount of the cornea according to the indication mark, and extreme value superposition is carried out on the defocus amounts of the lens and the cornea, so that the maximum defocus amount of a dioptric system formed by the lens and the cornea is maximized as far as possible, and the myopia control effect is improved. The defocus on the cornea is mainly caused by corneal astigmatism, and the position with the largest defocus generally appears in the vicinity of 90 ° azimuth and 270 ° azimuth. The exact location of which can be determined by detection.

In an exemplary embodiment of the invention, a difference between a maximum value and a minimum value of the defocus amount in the defocus area is not less than 1D, 2D, 3D, 4D, or 5D. This difference reflects the amplitude of defocus fluctuation in the out-of-focus region, and can be selected based on factors such as defocus threshold, lens power, patient tolerance, etc.

In an exemplary embodiment of the invention, the lens is a lens of a contact lens, and the out-of-focus area is located in an annular area with the center of the lens as a circle center, the inner diameter of the annular area is 3 mm-4 mm, and the outer diameter of the annular area is 5 mm-8 mm. In another exemplary embodiment of the invention, the lens is a lens of a frame glasses, and the out-of-focus area is located in an annular area with the center of the lens as a center, the inner diameter of the annular area is 6 mm-8 mm, and the outer diameter of the annular area is 8-12 mm. For lenses, the out-of-focus zone is required to exclude the central optical zone on the lens and areas that have little or no effect on myopia control, such as areas where projected light rays do not effectively enter the pupil. Some frame glasses make the defocus at the edge of the lens large, but the defocus in the above-mentioned area is not large, and do not have a good myopia control effect. Therefore, when the defocus amount of the defocus area of the lens is designed and calculated, the defocus amount needs to be designed and calculated according to the set defocus area range, so as to achieve an effective myopia control effect. The annular region may include a central optical region and an outer region of the out-of-focus region in addition to the out-of-focus region.

In an exemplary embodiment of the invention, the lens is a lens of a contact lens, and the defocus area includes a high focus area with a defocus amount no less than 2D, 2.5D, 3D, 3.5D, 4D, 4.5D, 5D, or 5.5D at any position. In another exemplary embodiment of the present invention, the lens is a lens of a frame glasses, and the defocus region includes a high focus region having a defocus amount of not less than 2.5D or 3D or 3.5D or 4D or 4.5D or 5D or 5.5D or 6D at any position.

In the present application, the high focus area is an area in the out-of-focus area for achieving a desired myopia control effect, and a out-of-focus threshold value may be set, and an area in which the out-of-focus amount at any position in the out-of-focus area is not less than the out-of-focus threshold value is determined as the high focus area. In this application, a point is also considered to be a special area. The lens of the frame glasses is at a certain distance from the eyeball, the defocusing amount on the lens can play a smaller role than that of the corneal contact lens, and therefore, when the high-focus area is determined, a higher threshold value can be selected when other conditions are the same.

In one example, the defocus threshold used to determine the high focus region may be selected to correspond to a defocus threshold with a myopia control success rate above 50%, such as 3.5D, 4D, 4.5D, etc., as described above. After the glasses are worn, the defocus amount of the lenses and the defocus amount of the patient's cornea can be subjected to extreme value superposition, so that the maximum defocus amount of a dioptric system consisting of the lenses and the cornea is larger than the maximum defocus amount of the lenses, and therefore the defocus amount of a designed high-focus area can be smaller than 3.5D when the lenses are designed. The selection of a particular defocus threshold may be based on factors such as the desired success rate of myopia control, corneal astigmatism of the patient, fitting of the patient to the lens, tolerance of the patient to high defocus, size of the clear field of view, and degree of myopia of the patient.

In the case of the embodiment shown in fig. 8A, the high focus region comprises one ring segment 121 arranged in the defocus region, but more than two ring segments are also possible. In addition, the shape of the high focal area may be a dot shape or other shapes. This is not limited by the present application.

In an exemplary embodiment of the invention, the high focus area falls within one or two or more than three sector areas, the sector areas are centered on the center of the lens, and the sum of central angles is not more than 30 degrees or 60 degrees or 90 degrees or 120 degrees or 150 degrees. The two edges of the sector area in which the high focus area falls are two connecting lines of the center of the lens and two points with the largest and the smallest direction angles in the high focus area. When there are multiple sector-shaped regions, the multiple sector-shaped regions can be uniformly distributed in the out-of-focus zone, such as centrally symmetric about the center of the lens, or axially symmetric about the diameter of the central optical zone, but are not limited thereto. The smaller the sum of the central angles of the fan-shaped areas in which the high-focus area falls, the larger the other areas (also called low-focus areas) with smaller defocus amount on the lens, which is beneficial to improving the wearing comfort, enlarging the clear vision and reducing the influence of the high defocus amount on the vision.

In an exemplary embodiment of the invention, the out-of-focus area comprises one or two or more than three high-focus areas, and the sum of central angles of the ring sections of the high-focus areas relative to the center of the lens is not less than 5 degrees, or 15 degrees, or 30 degrees, or 45 degrees, or 60 degrees. In the example shown in fig. 8A, the lens 1 has a high focus area in a ring segment with a central angle θ with respect to the center of the lens. The larger the sum of the central angles, the larger the proportion of the high focus area in the visual field, which is beneficial to the control of myopia but reduces the clear visual field. The central angle of the high focus area can be expressed as the included angle between two connecting lines from the two points with the maximum and minimum direction angles to the center of the lens in the high focus area.

In the two exemplary embodiments, the maximum value and the minimum value of the central angle corresponding to the high-focus area are limited, and an appropriate value can be selected according to the condition of a patient during actual lens fitting.

In an exemplary embodiment of the invention, the out-of-focus region comprises one or any combination of the following structures formed on the outer surface of the lens:

a curved surface with gradually changed defocusing amount;

a fixed focus area; and

and (4) point-shaped bulges.

In one example, the out-of-focus zone comprises a curved surface of gradual through-focus amount formed on the outer surface of the lens. In one example, the defocus area includes a plurality of fixed focus areas (with constant defocus amount in the area) formed on the outer surface of the lens, the defocus amounts of the fixed focus areas are different, and the fixed focus areas are in step-shaped transition. In one example, the out-of-focus zone comprises a spot-like protrusion formed in an area of the outer surface portion of the lens (e.g., within a ring segment having a central angle of 90 degrees), the spot-like protrusion constituting an out-of-focus zone in the out-of-focus zone.

The above structures may also be combined, for example, in one example, the out-of-focus area includes one or more fixed focus areas formed on the outer surface of the lens, which may form a part of the high focus area but is not limited thereto, and other areas adopt a curved surface structure with gradually changed out-of-focus amount. In one example, the defocus region comprises a defocus-graded curved surface formed on the outer surface of the lens, including one or more high-focus regions, and one or more point-like protrusions are further provided in at least one of the high-focus regions, and a larger Vmax value can be obtained in the high-focus region by the composite structure. And so on. Partial astigmatism may be brought when a curved surface with gradually changed defocus amount is formed on the outer surface of the lens, but a certain degree of astigmatism is acceptable, which is beneficial to myopia control.

In an exemplary embodiment of the invention, the defocus amount of the defocus area forms a peak value in the direction angle of 0-360 degrees, and the peak value is not less than 2D, 2.5D, 3D, 3.5D, 4D, 4.5D, 5D, or 5.5D; in another exemplary embodiment of the present invention, the defocus amount of the defocus region forms two peaks spaced 120 ° to 240 ° from each other in the 0 ° to 360 ° azimuth, wherein the first peak is not less than 2D or 2.5D or 3D or 3.5D or 4D or 4.5D or 5D or 5.5D, and the second peak is equal to the first peak or less than the first peak. The case of only one peak corresponds to the design of the lens for generating F1 in the model, and the case of two peaks corresponds to the design of the lens for generating F2 in the model, in which the defocus variation due to the original corneal astigmatism is applied to the lens design. Because the astigmatism of the cornea of a person mostly appears in the range (about plus or minus 45 degrees) taking the 90-degree direction angle and the 270-degree direction angle as the center, the design of the two peak values and the interval angles thereof is beneficial to realizing the extreme value superposition of the defocus amount of the lens and the cornea, generating a larger Vmax value, expanding the range of a high focus area in the visual field and achieving a better myopia control effect.

The peripheral defocused lens of the embodiment of the invention adopts new structural designs such as a structure that the defocusing amount changes in the circumferential direction and a structure beneficial to superposition of the lens and the cornea defocusing amount extreme value, and can achieve better myopia control effect.

In an exemplary embodiment of the invention, there is also provided a pair of frame glasses, comprising a frame and two lenses, wherein at least one of the two lenses adopts any one of the above-mentioned lenses with out-of-focus peripheral edges. In one example, the out-of-focus zones in the lens include a high focus zone that is located above or below the center of the lens. In another example, the out-of-focus zone in the lens comprises two in-focus zones, one above and the other below the center of the lens; wherein, the high focus area refers to an area with a defocus amount not less than 2.5D or 3D or 3.5D or 4D or 4.5D or 5D or 5.5D or 6D at any position in the out-of-focus area. In this application, a high focus zone is considered to be above the center of the lens if an upward vertical line through the center of the lens passes through the high focus zone, and below the center of the lens if a downward vertical line through the center of the lens passes through the high focus zone. The arrangement of the high focal zone above and/or below the center of the lens also helps to achieve extreme superimposition of defocus amounts of the lens and cornea, considering that corneal astigmatism of a person mostly occurs in a range (around plus or minus 45 °) centered at 90 ° azimuth and 270 ° azimuth. For a small portion of the population where corneal astigmatism occurs at other angles, the need for that portion can be met by manufacturing, selecting lenses with the high focal zone designed at other angles.

The above is for the design of peripheral out-of-focus lenses, and the present application also applies the above theory to the design of a orthokeratology lens, thereby providing a orthokeratology lens 2, as shown in fig. 9 and 10, comprising a base arc zone (i.e., central optical zone) 21, an inversion arc zone 22, a positioning arc zone 23, and a peripheral arc zone 24, wherein at least one of the base arc zone 21 and the inversion arc zone 22 has a structural variation in the circumferential direction. The circumferential variation here means that structural variation exists within a range of 0 to 360 degrees of a direction angle with the center of the lens as a circle center. Orthokeratology lenses do not directly correct vision themselves, but indirectly correct vision by reshaping the cornea and inhibit the progression of myopia. The traditional design is based on deforming the cornea into the shape of a basal arc surface to achieve the defocusing purpose. In the embodiment, the special design of the base arc area or the reversal arc area promotes the fluctuation of the shaped cornea in the circumferential direction, so that the expected maximum defocus amount can be reached.

In an exemplary embodiment of the invention, the reversal arc zone includes at least two ring segments, two are shown, wherein one ring segment 221 has a greater height than the other ring segment 222, see the section a-a of the lens in fig. 9 shown in fig. 10, the corneal shaping is snapped onto the cornea 3, and the first ring segment 221 of the reversal arc zone has a greater height than the other ring segment 222. The space of the deformation of the cornea at the position can be improved by increasing the height of the arc section, and the defocusing amount of the corresponding position on the cornea after the shaping is favorably improved. In another exemplary embodiment of the present invention, the reversal arc area may also be set to be an aspheric shape with gradually changing heights in the circumferential direction, so that the position on the cornea corresponding to the reversal arc area is changed in the circumferential direction by the defocus amount after being shaped, and a better myopia control effect is generated. In addition, the reversal arc area can be designed to be widened, for example, the width of the reversal arc area is increased from 1 mm-2 mm to 1.2 mm-2.2 mm or more under the condition of ensuring stable positioning. The width of the reversal arc area is increased, which is helpful for improving the defocusing amount of the position of the reversal arc area corresponding to the cornea. For the base arc area, under the condition of ensuring that the vision correction meets the requirement, an asymmetric structural design can be adopted to achieve the effect of changing the defocusing amount of the cornea after the shaping in the circumferential direction.

Since the correlation of defocus to myopia control is not clear, in previous practice, only the amount of defocus taken over the cornea was considered. According to the new theory of defocus and myopia control provided by the application, the embodiment of the invention provides the following method for acquiring the defocus quantity parameter so as to acquire the defocus quantity parameter associated with myopia control for occasions such as glasses fitting.

As shown in fig. 11, an exemplary embodiment of the present invention provides a method for acquiring a defocus amount parameter, including:

step 110, collecting defocus amounts of a plurality of sampling points on a cornea of a user in a naked eye state of the user, wherein the sampling points are distributed on a plurality of direction angles in a coordinate system taking the center of the cornea as an origin;

the collection of defocus on the cornea can be realized by using a cornea map instrument, and the cornea map instrument is a novel device which is assisted by a computer and can present a cornea surface curvature image, and can generate a cornea map. The defocus of the sample points selected on the cornea can be calculated from the corneal topography.

And 120, obtaining a defocus parameter according to the defocus of the plurality of sample points on the cornea.

In an exemplary embodiment of the invention, in the naked eye state of the user, the defocus quantity parameter obtained in the naked eye state before glasses fitting of a myope is used for glasses fitting of the myope; in another exemplary embodiment of the invention, in the naked eye state of the user, the defocus parameter obtained in the naked eye state after a myope shapes the cornea through a keratoplasty lens is used for evaluating the myopia control effect of the myope after wearing the keratoplasty lens. The orthokeratology lens worn by the myopic patient in the embodiment of the invention can be the orthokeratology lens in the embodiment of the invention, and can also be other orthokeratology lenses such as a traditional orthokeratology lens.

In an exemplary embodiment of the present invention, the defocus parameter includes one or any combination of the following parameters:

defocus amounts of a plurality of sample points on the cornea;

a maximum defocus on the cornea;

position information of a maximum defocus on the cornea;

the maximum defocus amount on the cornea and one or more set defocus threshold values;

one or more of the presence, number, size and position of the effective defocus area;

the maximum defocus on the cornea is determined according to the defocus of the plurality of sample points on the cornea, the effective defocus area refers to an area where the defocus at any position on the cornea is not less than a corresponding defocus threshold, and the defocus threshold is not less than 3.5D, 4D, 4.5D, 5D, or 5.5D.

In one example, determining a maximum defocus amount on the cornea from defocus amounts of a plurality of sample points on the cornea includes:

and taking the maximum value of the defocusing amount of the plurality of sample points on the cornea as the maximum defocusing amount on the cornea. This also provides a higher accuracy if there are a large number of spots. The position information of the maximum defocus on the cornea is the position information of the sample point with the maximum defocus; or

Determining the maximum value of the defocusing amount of each direction angle according to the defocusing amount of the sample point of each direction angle in the plurality of direction angles; performing curve fitting according to the defocusing amount on each direction angle to obtain a defocusing amount curve on the direction angle of 0-360 degrees; and determining the maximum peak value of the defocus curve as the maximum defocus on the cornea.

In addition to the above method, in an example, the plurality of sampling points on the cornea are uniformly distributed on the peripheral membrane, or a curved surface fitting may be performed according to the plurality of sampling points, and a maximum peak value of a curved surface obtained by fitting may be used as the maximum defocus amount on the cornea. The present application is not limited to a particular calculation.

There are different ways to select the spots on the cornea. For example, samples may be selected at least 18 equally spaced azimuth angles, each azimuth angle collecting defocus for at least 3 samples. For another example, the defocus amount of at least 50 samples may be collected at 360 equally spaced azimuth angles. The specific setting can be according to actual need such as the requirement of measurement accuracy.

An exemplary embodiment of the present invention further provides a method for obtaining a defocus amount parameter, as shown in fig. 12, including:

step 210, when a myope wears a corneal contact lens, acquiring defocus amounts of a plurality of sample points on a dioptric system consisting of the cornea and the lens of the myope, wherein the sample points are distributed on a plurality of direction angles in a coordinate system taking the center of the cornea as an origin;

the defocus values of the various spots on the dioptric system can also be detected using a corneal mapper or similar detection device. The defocus amounts of the plurality of samples on the dioptric system in this embodiment are defocus amounts of the plurality of samples on the front surface of the dioptric system.

And step 220, obtaining a defocus parameter according to the defocus amounts of a plurality of sample points on the dioptric system.

The defocus amount parameter obtained in this step is a defocus amount parameter on the dioptric system.

The contact lenses in this embodiment may or may not use the peripheral defocus lenses of the present application.

In an exemplary embodiment of the present invention, the obtained defocus parameter includes one or any combination of the following parameters:

a maximum defocus amount on the dioptric system;

the comparison result of the maximum defocus amount on the dioptric system and one or more set defocus thresholds;

the maximum defocus amount on the dioptric system is determined according to defocus amounts of a plurality of sample points on the dioptric system, and the defocus threshold value is not less than 3.5D, 4D, 4.5D, 5D or 5.5D. The method for determining the maximum defocus amount of the dioptric system can refer to the method for determining the maximum defocus amount of the cornea, and is not described in detail here.

In one example, one defocus threshold is set, for example, a threshold for determining whether the myopia control is successful, such as 4.5D, and in another example, a plurality of defocus thresholds, such as 3.5D and 4.5D or more, are set, and the maximum defocus amount is compared with the plurality of defocus thresholds, so that the section in which the maximum defocus amount is located can be represented more accurately, and the effectiveness of the myopia control can be quantitatively evaluated.

In an exemplary embodiment of the present invention, the defocus parameter obtained according to the defocus amounts of the plurality of sample points on the dioptric system includes: and determining the existence, quantity, size and position of an effective defocus area according to the defocus amounts of the plurality of sample points, wherein the effective defocus area refers to an area where the defocus amount at any position on the dioptric system is not less than a corresponding defocus threshold value, and the defocus threshold value is not less than 3.5D, 4D, 4.5D, 5D or 5.5D.

In this embodiment, according to the difference of the corresponding out-of-focus threshold, there may be one or more effective out-of-focus areas, and different effective out-of-focus areas are obtained by adopting different out-of-focus threshold determinations. For example, there may be an effective defocus area corresponding to a defocus threshold of 3.5D, an effective defocus area corresponding to a defocus threshold of 4.5D, and so on. There may be one or more of the same number of effective defocus regions. If the effective defocus area exists, the maximum defocus amount on the dioptric system is larger than the defocus threshold corresponding to the effective defocus area, and the myopia control effectiveness can be evaluated more finely by combining the size information of the effective defocus area. The size information of the effective defocus area can be represented by the size of the central angle corresponding to the effective defocus area, the area of the effective defocus area, or the like. Besides the size information, other information of the effective defocus area, such as specific position information, can be combined, and the relevance of the position information obtained by statistical analysis and the effectiveness of the myopia control can be combined for fine evaluation.

In an exemplary embodiment of the invention, the spectacles worn by the myope are contact lenses, the contact lenses use any one of the lenses according to the embodiments of the invention, and the lenses comprise an indicator mark for indicating the position with the largest defocus amount in the out-of-focus area of the lenses; before acquiring defocus amounts of a plurality of samples on the dioptric system, the method further comprises: and calibrating the wearing angle of the lens according to the indication mark of the lens, so that the position with the maximum defocus amount in the out-of-focus area of the lens is aligned with the position with the maximum defocus amount on the cornea of the myope. Because the myope should be calibrated to obtain a good myopia control effect when wearing the device, the calibration needs to be carried out before the defocus parameter is measured, and more accurate data can be obtained. The calibration of the position may be performed by rotating the lens by an angle about the axis connecting the lens center and the cornea center after the lens center is aligned with the cornea center.

After obtaining above-mentioned defocus parameter, obtain defocus parameter is used for assessing myopia control effect that myope worn the contact lens, for example, assess the effect that traditional peripheral out of focus contact lens was worn to myopia control by the patient, if the effect is not good can in time change other lenses like this application peripheral out of focus lens.

In an exemplary embodiment of the present invention, the defocus parameter includes a maximum defocus amount on the cornea, or a comparison result between the maximum defocus amount on the cornea and a defocus threshold value; the method for determining the myopia control effect according to the defocus quantity parameter comprises the following steps: judging whether the maximum defocus amount on the cornea is not smaller than the defocus threshold value or not according to the defocus amount parameter, if so, determining that the myopia control effect is effective, and if not, determining that the myopia control effect is ineffective; or

The defocus parameter comprises the maximum defocus on the cornea or the comparison result of the maximum defocus on the cornea and a plurality of set defocus threshold values; the method for determining the myopia control effect according to the defocus quantity parameter comprises the following steps: and judging whether the maximum defocus amount on the cornea is not less than one or more defocus threshold values according to the defocus amount parameter, if so, searching for a corresponding myopia control success rate according to the maximum defocus threshold value in the one or more defocus threshold values, and determining a myopia control effect according to the myopia control success rate.

In an exemplary embodiment of the present invention, the defocus amount parameter at least includes information on presence or absence and size of an effective defocus area; the method for determining the myopia control effect according to the defocus quantity parameter comprises the following steps: if the cornea has the effective out-of-focus area, searching the corresponding myopia control success rate according to the out-of-focus threshold corresponding to the effective out-of-focus area and the size information of the effective out-of-focus area, and determining the myopia control effect according to the myopia control success rate.

In the above embodiment, the determining the myopia control effect according to the myopia control success rate includes: directly using the myopia control success rate to represent a myopia control effect; or judging whether the myopia control success rate is not less than the expected success rate, if so, determining that the myopia control effect is effective, and if not, determining that the myopia control effect is ineffective.

An exemplary embodiment of the present invention also provides a fitting method, as shown in fig. 13, including:

step 310, acquiring a defocus parameter of a myope in an naked eye state before fitting glasses according to any method of the embodiment of the invention;

and 320, fitting glasses for the myope according to the defocus quantity parameter.

The glasses fitting can be selected from the manufactured glasses to a proper pair of glasses, and can also be a new personalized glasses designed for the myopes. The glasses can use the peripheral out-of-focus lenses of the application and can also use the traditional peripheral out-of-focus lenses.

In an exemplary embodiment of the present invention, the defocus parameter includes a maximum defocus on the cornea and position information of the maximum defocus; fitting a pair of glasses for the myope according to the defocus quantity parameter, comprising: and selecting peripheral defocused lenses of contact lenses or frame glasses for the myope, wherein the sum of the maximum defocused amount on the cornea of the myope and the defocused amount at the corresponding position of the lenses is not less than a set defocused threshold value after contraposition superposition, wherein the defocused threshold value is not less than 3.5D or 4D or 4.5D or 5D or 5.5D, and the defocused threshold value can be specifically selected according to the desired myopia inhibiting effect, tolerance of the patients and the like. The lens of the contact lens is directly attached to the cornea, and the center of the lens needs to be aligned with the center of the cornea before alignment. For the frame glasses, the lens and the cornea have a certain distance, the center of the lens can be aligned with the cornea before alignment, and the corresponding relation of other positions can refer to the original rule.

In an exemplary embodiment of the present invention, the defocus parameter includes defocus information of a plurality of samples on the cornea; fitting a pair of glasses for the myope according to the defocus quantity parameter, comprising: and selecting a peripheral out-of-focus lens of a contact lens or a frame glasses for the myope, so that when the myope wears the lens, after the out-of-focus amount on the cornea is superposed with the out-of-focus amount at the corresponding position of the lens in an alignment manner, at least an effective out-of-focus area exists and the size of the effective out-of-focus area meets the requirement, wherein the effective out-of-focus area refers to an area with an out-of-focus amount at any position not less than a corresponding out-of-focus threshold value, the out-of-focus threshold value is not less than 3.5D or 4.5D or 5D or 5.5D, and one out-of-focus threshold value can be specifically.

In one example, the size of the effective defocus area satisfies the requirement, including: the effective defocus area satisfies one or more of the following conditions:

the central angle of the ring section where the effective defocusing area is located relative to the center of the lens is not less than an angle threshold value, and the angle threshold value is a set value which is not less than 5 degrees, 15 degrees, 30 degrees, 45 degrees or 60 degrees;

the sum of the areas of the effective defocusing areas is not less than a set area threshold.

In an exemplary embodiment of the present invention, the lens is any one of the lenses described in the embodiments of the present invention; before the performing the overlay, the method further includes: the fitting angle of the lens is calibrated (which can be done in software) so that the position where the defocus amount is maximum in the out-of-focus zone of the lens is aligned with the position where the defocus amount is maximum on the cornea of the myope. And the alignment is carried out before the superposition, so that more accurate defocusing data can be obtained, and the required value of the maximum defocusing amount is reduced.

In an exemplary embodiment of the invention, the method further comprises: acquiring the diameter of the pupil of the myope; and selecting a lens of a frame glasses or a corneal contact lens for the myope, wherein the diameter of the central optical area of the lens is determined according to the diameter of the pupil, and the larger the diameter of the pupil is, the larger the diameter of the determined central optical area of the lens is. Here a personalized design according to the size of the patient's pupil. For example, the diameter of the pupil may be divided into 5 different size scales, and the diameter of the central optical zone of the lens may also be divided into 5 different size scales. If the diameter of the pupil is the smallest order, then the lens with the smallest diameter of the central optical zone is selected, and if the diameter of the pupil is the largest order, then the lens with the largest diameter of the central optical zone is selected. And so on. In other examples, the diameter of the pupil and the number of lens gradations need not be equal. The diameter of the pupil may not be graded, but the pupil diameter may be directly divided into a plurality of zones, each zone corresponding to the diameter of one of the central optical zones of the lens.

At present, whether a corneal plastic lens is effective for myopia control of a patient needs to be measured after the patient wears the corneal plastic lens for one year, and evaluation mainly aims at positioning and vision of the corneal plastic lens. This requires a significant amount of time and can delay the opportunity for effective treatment by other methods for patients who have ineffective control.

To this end, an exemplary embodiment of the present invention provides a method of evaluating the effect of myopia control using defocus, as shown in fig. 14, including:

step 410, acquiring defocus parameters obtained by a myope in an naked eye state after the cornea is shaped by a cornea shaping mirror according to any method in the embodiment of the invention;

and step 420, determining the myopia control effect of the cornea shaping mirror on the myope according to the defocus quantity parameter.

The defocus parameter comprises the maximum defocus on the cornea or the comparison result of the maximum defocus on the cornea and a plurality of set defocus threshold values; the method for determining the myopia control effect according to the defocus quantity parameter comprises the following steps: and judging whether the maximum defocus amount on the cornea is not less than one or more defocus threshold values according to the defocus amount parameter, if so, searching for a corresponding myopia control success rate according to the maximum defocus threshold value in the one or more defocus threshold values, and determining a myopia control effect according to the myopia control success rate. The myopia control success rate corresponding to the defocus threshold can be obtained and stored according to corresponding experimental data statistics.

In an exemplary embodiment of the present invention, the defocus amount parameter at least includes presence/absence of an effective defocus area and size information (when there is no effective defocus area, the size information and the like are null information); the method for determining the myopia control effect according to the defocus quantity parameter comprises the following steps: if the cornea has the effective out-of-focus area, searching the corresponding myopia control success rate according to the out-of-focus threshold corresponding to the effective out-of-focus area and the size information of the effective out-of-focus area, and determining the myopia control effect according to the myopia control success rate. The myopia control success rate corresponding to the defocus threshold and the size information of the effective defocus area can be obtained and stored according to corresponding experimental data statistics. If the defocus quantity parameter comprises a plurality of effective defocus areas corresponding to different defocus thresholds, a plurality of myopia control success rates can be found, and one effective defocus area is selected to determine the myopia control effect. For example, the myopia control success rate is found according to the effective defocus area corresponding to the maximum defocus threshold and the size information thereof, and the myopia control effect is determined using the found myopia control success rate, but the present application is not limited thereto. The myopia control success rate found according to the plurality of effective defocus areas and the size information thereof can also be comprehensively considered, for example, the maximum value, the average value or the minimum value is taken to determine the myopia control effect, and the application does not limit the effect.

In the above exemplary embodiments of the present invention, the determining the myopia control effect according to the myopia control success rate includes: directly using the myopia control success rate to represent a myopia control effect; or judging whether the myopia control success rate is not less than the expected success rate, if so, determining that the myopia control effect is effective, and if not, determining that the myopia control effect is ineffective.

In an exemplary embodiment of the invention, the myopia control effect is assessed within 2 weeks or within 1 month or within 3 months or within 6 months after the myopic patient wears the keratoplastic lens.

The above-described embodiments of the present invention provide a method for evaluating the effectiveness of myopia control using defocus parameters, which is different from previous evaluation methods. And whether the orthokeratology mirror is effective for the patient can be judged in a short time, so that the clinical efficiency is improved, and the condition of the patient is prevented from being delayed and other means for controlling myopia are avoided. The application provides a new evaluation standard of the orthokeratology lens, and has important significance.

The method for acquiring the defocus parameter, the method for fitting the glasses and the method for evaluating the myopia control effect of the embodiments of the invention can be realized by using computer equipment. As shown in fig. 15, the computer device includes a processor 50, a memory 60, and a computer program stored on the memory 60 and operable on the processor 50, and the processor 50 executes the computer program to implement the processing of any one of the methods according to the above-mentioned embodiments of the present invention.

An exemplary embodiment of the present invention also provides a computer-readable storage medium on which a computer program is stored, which, when executed by a processor, implements the processing of any one of the methods according to the above-described embodiments of the present invention.

It will be understood by those of ordinary skill in the art that all or some of the steps of the methods, systems, functional modules/units in the devices disclosed above may be implemented as software, firmware, hardware, and suitable combinations thereof. In a hardware implementation, the division between functional modules/units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component may have multiple functions, or one function or step may be performed by several physical components in cooperation. Some or all of the physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on computer readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). The term computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data, as is well known to those of ordinary skill in the art. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, Digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can accessed by a computer. In addition, communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media as known to those skilled in the art.

Claims

1. A method of obtaining defocus parameters, comprising:

in a naked eye state of a user, acquiring defocus amounts of a plurality of sampling points on a cornea of the user, wherein the sampling points are distributed on a plurality of direction angles in a coordinate system taking the center of the cornea as an origin;

obtaining defocus parameters according to defocus of a plurality of sample points on the cornea, wherein the defocus parameters are used for fitting a lens for a myope or evaluating the myopia control effect of the myope after wearing a cornea shaping lens, and the defocus parameters comprise one or any combination of the following parameters:

a maximum defocus on the cornea;

position information of a maximum defocus on the cornea;

2. The method of claim 1, wherein:

determining the maximum defocus amount on the cornea according to the defocus amounts of a plurality of sample points on the cornea, wherein the method comprises the following steps:

taking the maximum value of the defocus amounts of the plurality of sample points on the cornea as the maximum defocus amount on the cornea; or

3. The method of claim 1 or 2, wherein:

in the naked eye state of the user, the defocusing amount parameter is obtained in the naked eye state before glasses fitting of a myope, and the obtained defocusing amount parameter is used for glasses fitting of the myope; or

In the naked eye state of the user, the defocusing amount parameter obtained in the naked eye state of a myope after the cornea of the myope is shaped by the corneal shaping lens is used for evaluating the myopia control effect of the myope after the myope wears the corneal shaping lens.

4. A method of obtaining defocus parameters, comprising:

when a myope wears a corneal contact lens, acquiring defocus amounts of a plurality of sampling points on a dioptric system consisting of the cornea and a lens of the myope, wherein the sampling points are distributed on a plurality of direction angles in a coordinate system taking the center of the cornea as an origin;

obtaining a defocus parameter according to defocus of a plurality of sample points on the dioptric system, wherein the defocus parameter is used for evaluating the myopia control effect of the myope wearing the corneal contact lens, and the defocus parameter comprises one or any combination of the following parameters:

a maximum defocus amount on the dioptric system;

determining the existence, the quantity, the size and the position of an effective defocusing area according to the defocusing amount of the plurality of sample points;

the maximum defocus amount on the dioptric system is determined according to defocus amounts of a plurality of sample points on the dioptric system, and the defocus threshold value is not less than 3.5D, 4D, 4.5D, 5D or 5.5D;

the effective defocus area refers to an area where the defocus amount at any position on the dioptric system is not less than the corresponding defocus threshold.

5. The method of claim 4, wherein:

the glasses worn by the myope are corneal contact lenses, the lenses of the corneal contact lenses comprise a central optical area, an annular defocus area is arranged outside the central optical area, defocus of the defocus area varies in the annular direction, and the lenses further comprise an indicating mark for indicating the position of the lens with the largest defocus in the defocus area;

before the defocus amounts of a plurality of sample points on the dioptric system are collected, the method further comprises the following steps: and calibrating the wearing angle of the lens according to the indication mark of the lens, so that the position with the maximum defocus amount in the out-of-focus area of the lens is aligned with the position with the maximum defocus amount on the cornea of the myope.

6. A method of fitting a lens, comprising:

acquiring a defocus parameter of a myope in an naked eye state before fitting according to the method of claim 1 or 2;

and fitting the glasses for the myope according to the defocus quantity parameter.

7. The method of claim 6, wherein:

the defocus parameter comprises the maximum defocus on the cornea and the position information of the maximum defocus;

fitting a pair of glasses for the myope according to the defocus quantity parameter, comprising: and selecting peripheral out-of-focus lenses of contact lenses or frame glasses for the myope, wherein the sum of the maximum out-of-focus on the cornea of the myope and the out-of-focus at the corresponding position of the lenses is not less than a set out-of-focus threshold value after overlay, wherein the out-of-focus threshold value is not less than 3.5D or 4D or 4.5D or 5D or 5.5D.

8. The method of claim 6, wherein:

the defocus parameter comprises defocus information of a plurality of sample points on the cornea;

fitting a pair of glasses for the myope according to the defocus quantity parameter, comprising: and selecting a peripheral out-of-focus lens of a contact lens or frame glasses for the myope, so that when the myope wears the lens, after the out-of-focus amount on the cornea is superposed with the out-of-focus amount at the corresponding position of the lens in an alignment manner, at least an effective out-of-focus area exists and the size of the effective out-of-focus area meets the requirement, wherein the effective out-of-focus area refers to an area with the out-of-focus amount at any position not less than a corresponding out-of-focus threshold value, and the out-of-focus threshold value is not less than 3.5D or 4D or 4.5D or 5.

9. The method of claim 8, wherein:

the size of the effective defocusing area meets the requirement, and the method comprises the following steps: the effective defocus area satisfies one or more of the following conditions:

10. The method of claim 7 or 8, wherein:

the lens comprises a central optical area, an annular out-of-focus area is arranged outside the central optical area, the out-of-focus amount of the out-of-focus area changes in the annular direction, and the lens further comprises an indicating mark for indicating the position with the largest out-of-focus amount in the out-of-focus area of the lens;

before the performing the overlay, the method further includes: and calibrating the wearing angle of the lens, so that the position with the maximum defocus amount in the out-of-focus area of the lens is aligned with the position with the maximum defocus amount on the cornea of the myope.

11. The method of claim 6, wherein the method further comprises:

acquiring the diameter of the pupil of the myope;

and selecting a lens of a frame glasses or a corneal contact lens for the myope, wherein the diameter of the central optical area of the lens is determined according to the diameter of the pupil, and the larger the diameter of the pupil is, the larger the diameter of the determined central optical area of the lens is.

12. A computer device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the processor implements the process of the method according to any one of claims 1 to 11 when executing the computer program.

13. A computer device for assessing the effects of myopia control, comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor when executing the computer program implements the processes of:

acquiring defocus parameters obtained by a myope in an naked eye state after the cornea of the myope is shaped by a keratoplasty mirror according to the method of claim 1 or 2;

and determining the myopia control effect of the corneal shaping mirror on the myope according to the defocus quantity parameter.

14. The computer device of claim 13, wherein:

the defocus parameter comprises the maximum defocus on the cornea or the comparison result of the maximum defocus on the cornea and a set defocus threshold; the method for determining the myopia control effect according to the defocus quantity parameter comprises the following steps: judging whether the maximum defocus amount on the cornea is not smaller than the defocus threshold value or not according to the defocus amount parameter, if so, determining that the myopia control effect is effective, and if not, determining that the myopia control effect is ineffective; or

15. The computer device of claim 13, wherein:

the defocus amount parameters at least comprise the existence and size information of an effective defocus area;

the method for determining the myopia control effect according to the defocus quantity parameter comprises the following steps: if the cornea has the effective out-of-focus area, searching the corresponding myopia control success rate according to the out-of-focus threshold corresponding to the effective out-of-focus area and the size information of the effective out-of-focus area, and determining the myopia control effect according to the myopia control success rate.

16. The computer device of claim 14 or 15, wherein:

the determining of the myopia control effect according to the myopia control success rate comprises:

directly using the myopia control success rate to represent a myopia control effect; or

And judging whether the success rate of the myopia control is not less than the expected success rate, if so, determining that the myopia control effect is effective, and if not, determining that the myopia control effect is ineffective.

17. The computer device of any of claims 13 to 15, wherein:

the myopia control effect is assessed within 2 weeks or within 1 month or within 3 months or within 6 months of the myope wearing the keratoplastic lens.

18. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the processing of the method according to any one of claims 1 to 11.