Method and system for simulating the ocular fluorescence staining state after wearing a rigid contact lens

Abstract

The present invention provides a method, system, readable storage medium and electronic device for simulating the fluorescent staining state of an eye after wearing a hard contact lens. Firstly, missing data in each radial direction of the acquired corneal morphological data are filled, and the data in each radial direction are fitted, and data points with excessive deviation in the original data are eliminated, so as to completely and truly restore the morphology of the cornea. Secondly, by calculating the sagittal height difference between the lens and the cornea, it is ensured that the lens and the cornea have one or more contact points, so as to simulate the actual situation of the lens being worn on the cornea. Finally, the result is intuitively displayed in the form of an image, so that a fitter can judge the fitting of the contact lens according to the image, and help determine the final lens taking parameters of the patient.

Description

Technical Field

[0001] The present invention relates to the field of medical technologies, and particularly relates to a method, a system, a readable storage medium and an electronic device for simulating the eye fluorescence staining state after wearing a rigid contact lens. Background Art

[0002] Myopia refers to the refractive state in which parallel light rays are refracted by the eye refractive system and the focus falls in front of the retina when the human eye is in a relaxed state of accommodation. According to the World Vision Report released by the World Health Organization, by 2020, there will be approximately 2.6 billion myopic patients globally. From the statistical data in 2015, it can be found that 312 million patients are under 19 years old. Rigid gas permeable contact lenses (RGP) are one of the correction methods for refractive errors, mainly including daily-wear RGP and overnight orthokeratology lenses. Their materials have high oxygen permeability and good optical performance. Daily-wear RGP has good correction effects on high corneal astigmatism, keratoconus, etc. Overnight orthokeratology lenses help improve daytime uncorrected visual acuity and also promote the slowing down of the growth rate of the eye axis in teenagers.

[0003] Rigid gas permeable contact lenses need to be customized according to the corneal morphology of patients and are a type of patient-matched medical device. Therefore, the fitting of rigid gas permeable contact lenses needs to be performed by professional optometrists or doctors in medical institutions. Correct fitting can not only obtain clear vision, improve wearing comfort, but also enhance safety and avoid the occurrence of some complications.

[0004] Precisely measuring the eye parameters of patients and understanding the corneal morphology are the basis for fitting. This mainly includes measuring corneal curvature, diameter, etc. using corneal topography, which serves as the basis for selecting lens parameters. Currently, the most commonly used method to determine the final lens-taking parameters is the trial lens fitting method. The lens manufacturer provides multiple sets of trial lenses with different parameters, and the fitter selects the lens with the closest corneal parameters to the patient for trial fitting. After wearing the lens, the tear film on the eye surface is stained with fluorescein sodium ophthalmic test paper, and it can be observed under cobalt blue light illumination with a slit lamp microscope that the tear fluid between the lens and the cornea appears green. By observing the distribution state of the tear fluid, the contact position, degree, and range between the lens and the cornea, the fitting condition of the lens can be judged. If it is judged that the fitting of the lens is poor, different parameters of trial lenses are replaced according to the fitting result of the previous lens until the lens with the best fitting is found. However, wearing an inappropriate lens will increase the risk of corneal damage, and long-term trial fitting will also affect the acceptance and cooperation of patients; moreover, for orthokeratology lenses, even short-term trial fitting will have a certain shaping effect on the cornea, affecting the effect of the next pair of lenses. Lenses with different designs have different fitting rules, so the number of trial lenses should be reduced as much as possible to improve the fitting efficiency, and this process requires high experience from the fitter; if the trial lenses are not properly cleaned, there is a risk of cross-infection between individuals due to multiple people trying on the same lens. Therefore, a software fitting method is needed to replace multiple trial fittings to improve the wearing success rate. Summary of the Invention

[0005] The purpose of the present invention is to provide a method and system for simulating the ocular fluorescence staining state after wearing a rigid contact lens, so as to avoid trial fitting of lenses or reduce the number of lens trial fittings when fitting rigid contact lenses.

[0006] To solve the above technical problems, the method for simulating the ocular fluorescence staining state after wearing a rigid contact lens provided by the present invention includes:

[0007] Obtaining corneal morphology data, where the corneal morphology data includes the elevation and radial distance of each measurement point on multiple concentric rings;

[0008] Filling in the missing data in each radial direction of the corneal morphology data, and fitting according to the elevation and radial distance of the measurement points on multiple concentric rings in each radial direction to obtain a functional relationship between the elevation and the radial distance;

[0009] Obtaining a radial distance set, where the radial distance set includes the maximum radial distance value of the cornea, multiple different intermediate radial distance values, and a zero value, and substituting each radial distance value in the radial distance set into the functional relationship to calculate and obtain a corneal elevation set;

[0010] Calculating a lens elevation set of the rigid contact lens according to the lens parameters and the radial distance set;

[0011] Calculate the sagittal height difference set between the anterior corneal surface and the rigid contact lens based on the corneal sagittal height set and the lens sagittal height set, and obtain the tear film thickness between the anterior corneal surface and the posterior lens surface based on the calculation result; and,

[0012] Simulate the fluorescein staining state of the eye after wearing a rigid contact lens according to the tear film thickness.

[0013] Optionally, in the method of simulating the fluorescein staining state of the eye after wearing a rigid contact lens, the method of calculating the sagittal height difference set between the anterior corneal surface and the rigid contact lens based on the corneal sagittal height set and the lens sagittal height set, and obtaining the tear film thickness between the anterior corneal surface and the posterior lens surface based on the calculation result includes:

[0014] Establish a coordinate system with sagittal height as the ordinate and radial distance as the abscissa, place the values in the corneal sagittal height set and the lens sagittal height set in the coordinate system, and the corneal sagittal height set and the lens sagittal height set share the coordinate origin;

[0015] Calculate the sagittal height difference between the corneal sagittal height and the lens sagittal height corresponding to each radial distance value in the radial distance set.

[0016] If the minimum value ΔSagMin of the sagittal height differences corresponding to all radial distance values is equal to 0, then take the sagittal height difference ΔSag1 corresponding to each radial distance value as the tear film thickness between the anterior corneal surface and the posterior lens surface at the concentric ring where the corresponding radial distance value is located;

[0017] If there is at least one radial distance value corresponding to a sagittal height difference ΔSag2 less than 0, then take ΔSag2 + |ΔSagMin| as the tear film thickness between the anterior corneal surface and the posterior lens surface at the concentric ring where the corresponding radial distance value is located.

[0018] Optionally, in the method of simulating the fluorescein staining state of the eye after wearing a rigid contact lens, use the one-dimensional linear interpolation processing method to fill in the missing data in each radial direction of the corneal shape data.

[0019] Optionally, in the method of simulating the fluorescein staining state of the eye after wearing a rigid contact lens, the step of simulating the fluorescein staining state of the eye after wearing a rigid contact lens according to the tear film thickness includes:

[0020] Represent the relationship between the tear film thickness and the radial distance in the form of an image, use the depth of the image color to characterize the size of the tear film thickness, and the darker the image color, the smaller the tear film thickness.

[0021] Optionally, in the method of simulating the fluorescein staining state of the eye after wearing a rigid contact lens, the radial distance values of different values in the radial distance set change at a fixed step size.

[0022] Optionally, in the method for simulating the ocular fluorescence staining state after wearing a rigid contact lens, the following polynomial is used to fit the elevation and radial distance of the measurement points of multiple concentric rings in the same radial direction:

[0023] f(r) = a n r n + a n-1 r n-1 + a n-2 r n-2 + … + a1r + a0

[0024] where a n , a n-1 , …, a are polynomial coefficients, n is the number of terms, r represents the radial distance, and f(r) represents the elevation.

[0025] Optionally, in the method for simulating the ocular fluorescence staining state after wearing a rigid contact lens, the following aspheric formula is used to fit the elevation and radial distance of the measurement points of multiple concentric rings in the same radial direction:

[0026]

[0027] where c is the vertex curvature, r is the radial distance, k is the aspheric coefficient reflecting the deviation of the curve from the spherical surface, B and C are high-order term coefficients, and g(r) represents the elevation.

[0028] Based on the same idea, the system for simulating the ocular fluorescence staining state after wearing a rigid contact lens provided by the present invention includes:

[0029] A data acquisition module for acquiring corneal morphology data, where the corneal morphology data includes the elevation and radial distance of each measurement point on multiple concentric rings;

[0030] A data processing module for filling in the missing data in each radial direction of the corneal morphology data, and fitting according to the elevation and radial distance of the measurement points of multiple concentric rings in each radial direction to obtain a functional relationship between the elevation and the radial distance;

[0031] A data fitting module for obtaining a radial distance set, where the radial distance set includes the maximum radial distance value of the cornea, multiple different intermediate radial distance values, and a zero value, and substituting each radial distance value in the radial distance set into the functional relationship to calculate and obtain a corneal elevation set;

[0032] A calculation module, which is used to calculate a set of lens sag heights of a rigid contact lens according to lens parameters and the set of radial distances, and to calculate a set of sag height differences between the anterior corneal surface and the rigid contact lens according to the set of corneal sag heights and the set of lens sag heights, and to obtain the thickness of the tear film between the anterior corneal surface and the posterior lens surface based on the calculation results; and,

[0033] An image processing module, which is used to simulate the fluorescence staining state of the eye after wearing a rigid contact lens according to the thickness of the tear film.

[0034] Optionally, in the system for simulating the fluorescence staining state of the eye after wearing a rigid contact lens, the calculation module calculates a set of sag height differences between the anterior corneal surface and the rigid contact lens according to the set of corneal sag heights and the set of lens sag heights, and obtains the thickness of the tear film between the anterior corneal surface and the posterior lens surface based on the calculation results, including:

[0035] Establish a coordinate system with sag height as the ordinate and radial distance as the abscissa, place the values in the set of corneal sag heights and the set of lens sag heights in the coordinate system, and the set of corneal sag heights and the set of lens sag heights share the coordinate origin;

[0036] Calculate the sag height difference between the corneal sag height and the lens sag height corresponding to each radial distance value in the set of radial distances;

[0037] If the minimum value ΔSagMin of the sag height differences corresponding to all radial distance values is equal to 0, then use the sag height difference ΔSag1 corresponding to each radial distance value as the thickness of the tear film between the anterior corneal surface and the posterior lens surface at the concentric ring where the corresponding radial distance value is located;

[0038] If there is at least one radial distance value corresponding to a sag height difference ΔSag2 less than 0, then use ΔSag2 + |ΔSagMin| as the thickness of the tear film between the anterior corneal surface and the posterior lens surface at the concentric ring where the corresponding radial distance value is located.

[0039] Optionally, in the system for simulating the fluorescence staining state of the eye after wearing a rigid contact lens, the image processing module simulates the fluorescence staining state of the eye after wearing a rigid contact lens according to the thickness of the tear film, including:

[0040] Represent the relationship between the thickness of the tear film and the radial distance in the form of an image, and use the depth of the image color to characterize the size of the tear film thickness. The darker the image color, the smaller the tear film thickness.

[0041] Optionally, in the system for simulating the fluorescence staining state of the eye after wearing a rigid contact lens, it further includes:

[0042] An interaction module, which is used to display an image showing the relationship between the simulated tear film thickness difference and the radial distance by the image processing module. When any point on the image is clicked, the corresponding tear film thickness is displayed at the clicked position.

[0043] Optionally, in the system for simulating the ocular fluorescein staining state after wearing a rigid contact lens, the radial distance values of different values in the radial distance concentration change at a fixed step size.

[0044] The present invention also provides a readable storage medium, characterized in that a computer program is stored on the readable storage medium, and when the computer program is executed by a processor, the method for simulating the ocular fluorescein staining state after wearing a rigid contact lens as described above is implemented.

[0045] The present invention also provides an electronic device, characterized in that it includes a processor and a memory, a computer program is stored on the memory, and when the computer program is run by the processor, the method for simulating the ocular fluorescein staining state after wearing a rigid contact lens as described above is executed.

[0046] In summary, the method, system, readable storage medium and electronic device for simulating the ocular fluorescein staining state after wearing a rigid contact lens provided by the present invention. First, the missing data in each radial direction of the obtained corneal shape data is filled, and the data in each radial direction is fitted, and the data points with too large deviation in the original data are removed, which completely and truly restores the shape of the cornea. Secondly, by calculating the vertex height difference between the lens and the cornea, it is ensured that there is one or more contact points between the lens and the cornea, simulating the real situation of the lens worn on the cornea. Finally, the result is intuitively displayed in the form of an image, so that the fitter can judge the fitting situation of the contact lens according to the image, helping to determine the final lens-taking parameters for the patient. Compared with the prior art, it has the following beneficial effects:

[0047] (1) It is possible to see the fitting situation after wearing the rigid contact lens without the need for trial fitting, which is convenient for determining the parameter prescription for taking the lens for different patients and helps to improve the fitting success rate;

[0048] (2) It helps to avoid or reduce trial fitting and reduce the risk of damage to the human eye caused by inappropriate lenses;

[0049] (3) Repeated trial fittings within a short period of time will change the corneal shape, which will affect the subsequent judgment of whether the lens is suitable. The present invention is based on the original corneal shape for simulation and is not interfered by the previous trial fittings;

[0050] (4) There is no need to use trial lenses for trial fitting, which can avoid cross-infection between individuals caused by improper cleaning of trial lenses and is cleaner and more hygienic. Description of the Drawings

[0051] Figure 1 Flow chart of the method for simulating the ocular fluorescence staining state after wearing a rigid contact lens provided by an embodiment of the present invention;

[0052] Figure 2 Schematic diagram of filling missing data in each radial direction in an embodiment of the present invention;

[0053] Figure 3 Comparison chart before and after filling missing data in each radial direction in an embodiment of the present invention;

[0054] Figure 4 Schematic diagram of the state where ΔSag≥0 between the lens and the cornea in an embodiment of the present invention;

[0055] Figure 5 Schematic diagram of the state where ΔSag<0 between the lens and the cornea in an embodiment of the present invention;

[0056] Figure 6 Schematic diagram of the state where the lens is lowered by |ΔSagMin| when ΔSag<0 between the lens and the cornea in an embodiment of the present invention;

[0057] Figure 7 Schematic diagram of the tear film thickness distribution obtained by comparing ΔSag between the lens and the cornea in an embodiment of the present invention;

[0058] Figure 8 Schematic diagram of the tear film thickness obtained by using the processed data and displayed on the image coordinates in an embodiment of the present invention;

[0059] Figure 9 Schematic diagram of the tear film thickness obtained by using the original data and displayed on the image coordinates in an embodiment of the present invention;

[0060] Figure 10 Block diagram of the composition of the system for simulating the ocular fluorescence staining state after wearing a rigid contact lens provided by an embodiment of the present invention;

[0061] Among them, the descriptions of each reference numeral are as follows:

[0062] 1 - back surface of the lens; 2 - anterior surface of the cornea; 3 - tear film;

[0063] 101 - data acquisition module; 102 - data processing module; 103 - data fitting module; 104 - calculation module; 105 - image processing module 105; 106 - interaction module. Detailed implementation manners

[0064] To make the objectives, advantages, and features of the present invention clearer, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the accompanying drawings are in a very simplified form and not drawn to scale, and are only used to conveniently and clearly assist in explaining the objectives of the embodiments of the present invention. In addition, the structures shown in the accompanying drawings are often part of the actual structures. In particular, the emphases to be shown in the respective drawings are different, and sometimes different scales are used. It should also be understood that unless otherwise specified or indicated, the terms "first", "second", "third", etc. in the specification are only used to distinguish the various components, elements, steps, etc. in the specification, rather than to represent the logical relationships or sequential relationships, etc. between the various components, elements, steps.

[0065] As Figure 1 shown, an embodiment of the present invention provides a method for simulating the ocular fluorescence staining state after wearing a rigid contact lens. The method includes the following steps:

[0066] S11, obtaining corneal shape data, where the corneal shape data includes the elevation and radial distance of each measurement point on a plurality of concentric rings;

[0067] S12, filling in the missing data in each radial direction of the corneal shape data, and fitting according to the elevation and radial distance of the measurement points on a plurality of the concentric rings in each radial direction to obtain a functional relationship of elevation with respect to radial distance;

[0068] S13, obtaining a radial distance set, where the radial distance set includes the maximum radial distance value of the cornea, a plurality of different intermediate radial distance values, and a zero value, and substituting each radial distance value in the radial distance set into the functional relationship respectively to calculate and obtain a corneal elevation set;

[0069] S14, calculating a lens elevation set of the rigid contact lens according to the lens parameters and the radial distance set;

[0070] S15, calculating a set of elevation differences between the anterior corneal surface and the rigid contact lens according to the corneal elevation set and the lens elevation set, and obtaining the tear film thickness between the anterior corneal surface and the posterior lens surface based on the calculation result;

[0071] S16, simulating the ocular fluorescence staining state after wearing the rigid contact lens according to the tear film thickness.

[0072] The above steps will be further described in detail below.

[0073] In step S11, corneal shape data can be collected using a corneal topographer. The corneal topographer measures using the Placido ring principle. For example, when the corneal topographer is a Medmont E300USB, it measures using 32 concentric rings, with 300 measurement points on each ring. The acquisition diameter range is 0.25 mm to 11 mm, and the elevation and radial distance of each measurement point on the cornea are exported.

[0074] The exported radial distance and elevation data are in one-to-one correspondence. From these data, the general shape of the cornea can be known, but there are many missing points in these data. This is because during the measurement process, it is difficult for the patient to fully expose the cornea, and the Placido ring cannot completely cover the cornea. Especially due to the presence of eyelids and eyelashes, it is difficult to obtain corneal data in the peripheral area, which will affect the judgment of whether the lens edge arc fits. And if the patient's ocular surface is dry, the tear film is prone to rupture during the measurement process, resulting in deformation and dislocation of the projection points of the Placido ring on the human eye, thereby affecting the smoothness of the measurement data.

[0075] To restore the cornea as realistically and completely as possible and reduce the influence of these measurement defects, after step S11 is executed, step S12 and step S13 are then executed to obtain the complete corneal shape after fitting, and at the same time, points with large measurement errors caused by tear film rupture in the original data can be excluded.

[0076] In step S12, a one-dimensional linear interpolation processing method can be used to fill in the missing data in each radial direction. For example, as Figure 2 shown, assume that the corneal shape data includes data of three concentric rings. For the outermost concentric ring, the data at point A is missing. Then, the data at points B and C on the inner concentric ring that are on the same radial line as point A are used to calculate the data at point A. It should be noted that Figure 2 shown is only an example of the specific processing method of one-dimensional linear interpolation processing. As can be seen from Figure 3 , after filling in the missing data in each radial direction, the integrity of the data is improved.

[0077] In step S12, the following polynomial can be used to fit the elevation and radial distance of the measurement points of multiple concentric rings on the same radial line:

[0078] f(r) = a n r n + a n-1 r n-1 + a n-2 r n-2 + … + a1r + a0; (1)

[0079] Where, a n , a n-1, …, a are polynomial coefficients, n is the number of terms, r represents the radial distance, and f(r) represents the sagitta.

[0080] Alternatively, use the following aspheric formula to fit the sagitta and radial distance of the measurement points of multiple concentric rings on the same radial direction:

[0081]

[0082] where c is the vertex curvature, r is the radial distance, k is the aspheric coefficient reflecting the deviation between the curve and the spherical surface, B and C are high-order term coefficients, and g(r) represents the sagitta.

[0083] For example, when using the above polynomial (1) to fit the sagitta and radial distance of the measurement points of multiple concentric rings on the same radial direction, the fitting process can be as follows:

[0084] Assume that there are data of three concentric rings in the corneal shape data. On the target radial direction, substitute the sagitta and radial distance of the measurement points of the first concentric ring into the above polynomial (1) to obtain:

[0085] f(r1) = a3r1 3 + a2r1 2 + a1r1 + a0; (3)

[0086] Substitute the sagitta and radial distance of the measurement points of the second concentric ring into the above polynomial (1) to obtain:

[0087] f(r2) = a3r2 3 + a2r2 2 + a1r2 + a0; (4)

[0088] Substitute the sagitta and radial distance of the measurement points of the third concentric ring into the above polynomial (1) to obtain:

[0089] f(r3) = a3r3 3 + a2r3 2 + a1r3 + a0; (5)

[0090] According to the above formulas (3), (4), and (5), a0, a1, a2, and a3 can be obtained. Therefore, when performing step S13, after re-obtaining the maximum radial distance value, multiple different intermediate radial distance values, and zero value of the cornea from the original corneal shape data obtained in step S11, substitute the re-obtained radial distances into the function relationship with known a0, a1, a2, and a3: f(r) = a3r 3 + a2r 2In +a1r + a0, the corresponding sagittal height can be calculated. Assume that the aspheric formula (2) is used for fitting, and then the principle of calculating the sagittal height based on the re-obtained maximum radial distance value, multiple different intermediate radial distance values, and zero radial distance of the cornea is similar, and will not be elaborated here.

[0091] According to the set of corneal sagittal heights calculated in step S13, the complete corneal sagittal height can be obtained, and at the same time, points with large measurement errors caused by tear film rupture in the original corneal data can be excluded. Specifically, the original corneal shape data may include some deformed and misaligned points. By redefining the radial distance and substituting it into the functional relationship for calculation, some inaccurate points can be excluded. In a preferred embodiment, the multiple obtained radial distance values change at a fixed step size, that is, the multiple concentric rings corresponding to the multiple radial distance values are arranged at equal intervals. When the multiple radial distances change at a fixed step size, the influence of deformed and misaligned points can be better excluded.

[0092] As mentioned above, by using corneal topography to collect corneal shape data, when a new radial distance is obtained, it should be ensured that it does not exceed the measurement range of the corneal topography; that is, the radial distance set includes the maximum radial distance value of the cornea, multiple different intermediate radial distance values, and zero value.

[0093] In step S14, the existing rigid contact lens design method can be used to input relevant parameters for the lenses customized by the optometrist for this patient, such as the refractive power FlatK in the corneal flat direction, the lens diameter, etc., and calculate the lens sagittal height corresponding to each point at each re-obtained radial distance to obtain the set of lens sagittal heights of the rigid contact lens, so as to obtain the complete lens sagittal height.

[0094] In step S15, specifically, the method of calculating the set of sagittal height differences between the anterior corneal surface and the rigid contact lens based on the set of corneal sagittal heights and the set of lens sagittal heights, and obtaining the tear film thickness between the anterior corneal surface and the posterior lens surface based on the calculation result may include:

[0095] Establish a coordinate system with the sagittal height as the ordinate and the radial distance as the abscissa, place the values in the set of corneal sagittal heights and the set of lens sagittal heights in the coordinate system, and the set of corneal sagittal heights and the set of lens sagittal heights share the coordinate origin;

[0096] Calculate the sagittal height difference between the corneal sagittal height and the lens sagittal height corresponding to each radial distance value in the set of radial distances;

[0097] If the minimum value ΔSagMin of the sagittal height differences corresponding to all radial distance values is equal to 0, then the sagittal height difference ΔSag1 corresponding to each radial distance value is used as the tear film thickness between the anterior corneal surface and the posterior lens surface at the concentric ring where the corresponding radial distance value is located;

[0098] If there is at least one value of the radial distance for which the difference in sagittal height ΔSag2 is less than 0, then ΔSag2 + |ΔSagMin| is taken as the thickness of the tear film between the anterior corneal surface and the posterior lens surface at the concentric ring corresponding to the value of the radial distance.

[0099] Specifically, as Figure 4 and Figure 5 shown, a coordinate system is established, with the sagittal height as the ordinate and the radial distance as the abscissa, and the point with a radial distance of zero as the origin of coordinates. The set of corneal sagittal heights and the set of lens sagittal heights are placed in the coordinate system. In the coordinate system, the curves of the set of corneal sagittal heights and the set of lens sagittal heights can be regarded as the anterior corneal surface 2 and the posterior lens surface 1. Calculate the difference in sagittal height ΔSag between the corneal sagittal height Zc and the lens sagittal height Zlens at each radial distance, ΔSag = Zc - Zlens. As Figure 4 shown, if the minimum value ΔSagMin of the differences in sagittal height corresponding to all values of the radial distance is equal to 0, it indicates that there is one or more contact points between the posterior lens surface 1 and the anterior corneal surface 2, and the thickness T of the tear film 3 between the anterior corneal surface 2 and the posterior lens surface 1 at the concentric ring corresponding to the value of the radial distance is T = ΔSag. As Figure 5 shown, if there are points where ΔSag < 0, it indicates that at this time the sagittal height of the posterior lens surface 1 is greater than that of the anterior corneal surface 2, and the posterior lens surface 1 is embedded in the anterior corneal surface 2. Therefore, as Figure 6 shown, the overall sagittal height of the posterior lens surface 1 can be reduced until it just touches the anterior corneal surface 2. Therefore, the overall sagittal height of the posterior lens surface 1 is decreased by |ΔSagMin|. After adjustment, the thickness T of the tear film 3 between the anterior corneal surface 2 and the posterior lens surface 1 at the concentric ring corresponding to the value of the radial distance is T = ΔSag + |ΔSagMin|.

[0100] Preferably, in step S16, the simulating the state of ocular fluorescein staining after wearing a rigid contact lens according to the tear film thickness includes: displaying the tear film thickness as shown in Figure 7 at the corresponding coordinates of the image as shown in Figure 8 and using the darkness of the image color to represent the size of the tear film thickness. The darker the image color, the smaller the tear film thickness. As Figure 8 shown, the darker the color, the thinner the tear film layer and the better the fit between the lens and the cornea; the lighter the color, the thicker the tear film layer and the greater the difference in sagittal height between the posterior lens surface and the anterior corneal surface. When the image is displayed on the interactive interface of the computer, when the mouse is clicked on any point of the lens, the tear film thickness at the current point will be displayed.

[0101] Figure 9 shown is directly placing the original data obtained from corneal topography and the lens at the same origin of coordinates, calculating the difference in sagittal height between the two, so as to obtain the tear film thickness corresponding to each coordinate point and the image converted according to the tear film thickness. Comparing Figure 8 andFigure 9 It can be seen that after the above steps S12 to S14, the shape of the cornea is restored more completely and truly.

[0102] As Figure 10 shown, an embodiment of the present invention further provides a system for simulating the ocular fluorescence staining state after wearing a rigid contact lens, including:

[0103] A data acquisition module 101, which is used to acquire corneal shape data, and the corneal shape data includes the elevation and radial distance of each measurement point on a plurality of concentric rings;

[0104] A data processing module 102, which is used to fill in the missing data in each radial direction of the corneal shape data, and perform fitting according to the elevation and radial distance of the measurement points of a plurality of the concentric rings in each radial direction to obtain a functional relationship between the elevation and the radial distance;

[0105] A data fitting module 103, which is used to obtain a radial distance set, the radial distance set includes the maximum radial distance value of the cornea, a plurality of different intermediate radial distance values and zero values, and substitute each radial distance value in the radial distance set into the functional relationship respectively to calculate and obtain a corneal elevation set;

[0106] A calculation module 104, which is used to calculate the lens elevation set of the rigid contact lens according to the lens parameters and the radial distance set, and is used to calculate the elevation difference set between the anterior surface of the cornea and the rigid contact lens according to the corneal elevation set and the lens elevation set, and obtain the tear film thickness between the anterior surface of the cornea and the posterior surface of the lens based on the calculation result; and,

[0107] An image processing module 105, which is used to simulate the ocular fluorescence staining state after wearing a rigid contact lens according to the tear film thickness.

[0108] That is, the data acquisition module 101 is used to implement Figure 1 the step S11 shown, the data processing module 102 is used to implement Figure 1 the step S12 shown, the data fitting module 103 is used to implement Figure 1 the step S13 shown, the calculation module 104 is used to implement Figure 1 the step S14 and step S15 shown in Figure 1Step S16 shown therein. Thus, for the specific descriptions of the functions that can be achieved by the data acquisition module 101, the data processing module 102, the data fitting module 103, the calculation module 104, and the image processing module 105, reference can be made to the relevant descriptions of steps S11 - S16 shown in the part of the method for simulating the ocular fluorescein staining state after wearing a rigid contact lens as described above. Duplications will not be elaborated. Figure 1 In addition, the system for simulating the ocular fluorescein staining state after wearing a rigid contact lens can achieve similar technical effects as the method for simulating the ocular fluorescein staining state after wearing a rigid contact lens described above, which will not be elaborated here.

[0109] Optionally, the system for simulating the ocular fluorescein staining state after wearing a rigid contact lens provided in an embodiment of the present invention may further include: an interaction module 106. The interaction module 106 is configured to display an image of the relationship between the simulated tear film thickness difference and the radial distance. That is, after the image processing module 105 simulates the fluorescein staining state of the eye after wearing a rigid contact lens based on the tear film thickness, the simulated fluorescein staining image is displayed through the interaction module 106. The interaction module 106 may be, for example, an electronic screen. When any point on the fluorescein staining image displayed on the interaction module is clicked with a mouse, the tear film thickness at that point will be displayed. In addition, the interaction module 106 may also be used to display the tear film thickness data calculated by the calculation module 104 between the anterior corneal surface and the posterior lens surface. As Figure 7 shown, this tear film thickness data can be displayed in the form of a statistical image.

[0110] It can be understood that the data acquisition module 101, data processing module 102, data fitting module 103, calculation module 104, image processing module 105, and interaction module 106 can be implemented in one device, or any one of the modules can be split into multiple sub-modules. Alternatively, at least part of the functions of one or more of the data acquisition module 101, data processing module 102, data fitting module 103, calculation module 104, image processing module 105, and interaction module 106 can be combined with at least part of the functions of other modules and implemented in one functional module. According to an embodiment of the present invention, at least one of the data acquisition module 101, data processing module 102, data fitting module 103, calculation module 104, image processing module 105, and interaction module 106 can be at least partially implemented as a hardware circuit, such as a field-programmable gate array (FPGA), programmable logic array (PLA), system on chip, system on substrate, system on package, application-specific integrated circuit (ASIC), or can be implemented in any other reasonable way of integrating or packaging circuits, etc., in hardware or firmware, or in an appropriate combination of software, hardware, and firmware implementation methods. Alternatively, at least one of the data acquisition module 101, data processing module 102, data fitting module 103, calculation module 104, image processing module 105, and interaction module 106 can be at least partially implemented as a computer program module, and when the program is run on a computer, it can execute the functions of the corresponding module.

[0111] From the description of the above embodiments, those skilled in the art can clearly understand that the present invention can be implemented by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solution of the present invention, in essence, or the part of the features that contribute to the prior art can be embodied in the form of a computer program, and the computer program can be stored in a readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc. Therefore, the embodiments of the present invention also provide an electronic device, the electronic device includes a processor and a memory, and a computer program is stored on the memory. When the computer program is executed by the processor, it implements the method for simulating the ocular fluorescence staining state after wearing a rigid contact lens described in the embodiments of the present invention or some parts of the embodiments. In addition, the embodiments of the present invention also provide a readable storage medium, and a computer program is stored in the readable storage medium. When the computer program is executed by the processor, it implements the method for simulating the ocular fluorescence staining state after wearing a rigid contact lens described in the embodiments of the present invention or some parts of the embodiments.

[0112] In summary, the method, system, readable storage medium and electronic device for simulating the fluorescent staining state of the eye after wearing hard contact lenses provided by the present invention, first, fill in the missing data in each radial direction of the acquired corneal morphology data, and fit the data in each radial direction, eliminate the data points with excessive deviation in the original data, and completely and truly restore the morphology of the cornea. Secondly, by calculating the sagittal height difference between the lens and the cornea, it is ensured that the lens and the cornea have one or more contact points, simulating the actual situation of the lens being worn on the cornea. Finally, the results are intuitively displayed in the form of images, so that the fitter can judge the fitting of the contact lens based on the image, and help determine the patient's final lens removal parameters. Compared with the prior art, the present invention has the following beneficial effects: it is possible to see the fitting status of hard contact lenses after wearing them without having to try on them, which makes it easy to determine the prescription parameters for lens selection for different patients and helps to improve the fitting success rate; it helps to avoid or reduce trial wearing and reduce the risk of harm to the human eye caused by inappropriate lenses; multiple trial wearing in a short period of time will change the corneal morphology, thereby affecting the judgment of whether subsequent lenses are suitable. The present invention performs simulation based on the original corneal morphology and is not affected by previous trial wearing; cross infection between individuals caused by multiple people trying on improperly cleaned trial lenses can be avoided.

[0113] In addition, it should be recognized that although the present invention has been disclosed as a preferred embodiment, the above embodiment is not intended to limit the present invention. For any technician familiar with the art, without departing from the scope of the technical solution of the present invention, the technical content disclosed above can be used to make many possible changes and modifications to the technical solution of the present invention, or modified into equivalent embodiments of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still belongs to the scope of protection of the technical solution of the present invention.

Claims

1. A method for simulating the ocular fluorescence staining state after wearing a rigid contact lens, characterized in that, Comprising: Obtaining corneal shape data, where the corneal shape data includes the sagittal height and radial distance of each measurement point on multiple concentric rings; Filling in the missing data in each radial direction of the corneal shape data, and performing fitting based on the sagittal height and radial distance of the measurement points on multiple concentric rings in each radial direction to obtain a functional relationship of the sagittal height with respect to the radial distance; Obtaining a radial distance set, where the radial distance set includes the maximum radial distance value of the cornea, multiple different intermediate radial distance values, and a zero value, and substituting each radial distance value in the radial distance set into the functional relationship respectively to calculate a corneal sagittal height set; Calculating a lens sagittal height set of the rigid contact lens according to the lens parameters and the radial distance set; Calculating a sagittal height difference set between the anterior corneal surface and the rigid contact lens according to the corneal sagittal height set and the lens sagittal height set, and obtaining the tear film thickness between the anterior corneal surface and the posterior lens surface based on the calculation result; And, Simulating the fluorescence staining state of the eye after wearing the rigid contact lens according to the tear film thickness, where simulating the fluorescence staining state of the eye after wearing the rigid contact lens according to the tear film thickness includes: representing the relationship between the tear film thickness and the radial distance in the form of an image, using the depth of the image color to characterize the size of the tear film thickness, and the darker the image color, the smaller the tear film thickness.

2. The method for simulating the ocular fluorescence staining state after wearing a rigid contact lens as claimed in claim 1, wherein, The method for calculating the sagittal height difference set between the anterior corneal surface and the rigid contact lens according to the corneal sagittal height set and the lens sagittal height set, and obtaining the tear film thickness between the anterior corneal surface and the posterior lens surface based on the calculation result includes: Establishing a coordinate system with the sagittal height as the ordinate and the radial distance as the abscissa, placing each value in the corneal sagittal height set and the lens sagittal height set in the coordinate system, and the corneal sagittal height set and the lens sagittal height set share the coordinate origin; Calculating the sagittal height difference between the corneal sagittal height and the lens sagittal height corresponding to each radial distance value in the radial distance set; If the minimum value ΔSagMin of the sagittal height differences corresponding to all radial distance values is equal to 0, then taking the sagittal height difference ΔSag1 corresponding to each radial distance value as the tear film thickness between the anterior corneal surface and the posterior lens surface at the concentric ring where the corresponding radial distance value is located; If there is at least one radial distance value corresponding to a sagittal height difference ΔSag2 less than 0, then taking ΔSag2 + |ΔSagMin| as the tear film thickness between the anterior corneal surface and the posterior lens surface at the concentric ring where the corresponding radial distance value is located.

3. The method for simulating the ocular fluorescence staining state after wearing a rigid contact lens according to claim 1, wherein Using a one-dimensional linear interpolation processing method to fill in the missing data in each radial direction of the corneal shape data.

4. The method for simulating the ocular fluorescence staining state after wearing a rigid contact lens according to claim 1, wherein The radial distance values of different values in the radial distance set change at a fixed step size.

5. The method for simulating the ocular fluorescence staining state after wearing a rigid contact lens as claimed in claim 1, wherein Using the following polynomial to fit the sagittal height and radial distance of the measurement points on multiple concentric rings in the same radial direction: f(r) = a n r n + a n-1 r n-1 + a n-2 r n-2 + … + a1r + a0 where a n , a n-1 , …, a are polynomial coefficients, n is the number of terms, r represents the radial distance, and f(r) represents the sagitta.

6. The method for simulating the ocular fluorescence staining state after wearing a rigid contact lens according to claim 1, wherein, Using the following aspheric formula to fit the sagittal height and radial distance of the measurement points on multiple concentric rings in the same radial direction: Where, c is the vertex curvature, r is the radial distance, k is the aspheric coefficient, reflecting the deviation of the curve from the spherical surface, B and C are high-order term coefficients, and g(r) represents the sagittal height.

7. A system for simulating the ocular fluorescence staining state after wearing a rigid contact lens, characterized in that, Comprising: A data acquisition module, which is used to acquire corneal shape data, and the corneal shape data includes the elevation and radial distance of each measurement point on multiple concentric rings; A data processing module, which is used to fill in the missing data in each radial direction of the corneal shape data, and perform fitting based on the elevation and radial distance of the measurement points of multiple concentric rings in each radial direction to obtain a functional relationship between the elevation and the radial distance; A data fitting module, which is used to obtain a radial distance set, the radial distance set includes the maximum radial distance value of the cornea, multiple different intermediate radial distance values and zero values, and substitute each radial distance value in the radial distance set into the functional relationship respectively to calculate and obtain a corneal elevation set; A calculation module, which is used to calculate the lens elevation set of the rigid contact lens according to the lens parameters and the radial distance set, and is used to calculate the elevation difference set between the anterior corneal surface and the rigid contact lens according to the corneal elevation set and the lens elevation set, and obtain the tear thickness between the anterior corneal surface and the posterior lens surface based on the calculation result; and, An image processing module, which is used to simulate the fluorescence staining state of the eye after wearing the rigid contact lens according to the tear thickness. The image processing module simulating the fluorescence staining state of the eye after wearing the rigid contact lens according to the tear thickness includes: representing the relationship between the tear thickness and the radial distance in the form of an image, and using the depth of the image color to characterize the size of the tear thickness, and the darker the image color, the smaller the tear thickness.

8. The system for simulating the ocular fluorescence staining state after wearing a rigid contact lens according to claim 7, wherein The calculation module calculating the elevation difference set between the anterior corneal surface and the rigid contact lens according to the corneal elevation set and the lens elevation set, and obtaining the tear thickness between the anterior corneal surface and the posterior lens surface based on the calculation result includes: establishing a coordinate system with the elevation as the ordinate and the radial distance as the abscissa, placing each value in the corneal elevation set and the lens elevation set in the coordinate system, and the corneal elevation set and the lens elevation set share the coordinate origin; Calculating the elevation difference between the corneal elevation and the lens elevation corresponding to each radial distance value in the radial distance set; If the minimum value ΔSagMin of the elevation differences corresponding to all radial distance values is equal to 0, then take the elevation difference ΔSag1 corresponding to each radial distance value as the tear thickness between the anterior corneal surface and the posterior lens surface at the concentric ring where the corresponding radial distance value is located; If there is at least one radial distance value corresponding to an elevation difference ΔSag2 less than 0, then take ΔSag2 + |ΔSagMin| as the tear thickness between the anterior corneal surface and the posterior lens surface at the concentric ring where the corresponding radial distance value is located.

9. The system for simulating the ocular fluorescence staining state after wearing a rigid contact lens according to claim 7, wherein It further includes: An interaction module, which is used to display the image of the relationship between the tear thickness difference simulated by the image processing module and the radial distance. When any point on the image is clicked, the corresponding tear thickness is displayed at the clicked place.

10. The system for simulating the ocular fluorescence staining state after wearing a rigid contact lens as claimed in claim 7, wherein The radial distance values of different values in the radial distance set change at a fixed step size.

11. A readable storage medium, characterized in that, A computer program is stored on the readable storage medium. When the computer program is executed by a processor, a method for simulating the ocular fluorescence staining state after wearing a rigid contact lens as described in any one of claims 1 to 6 is implemented.

12. An electronic device, characterized in that, It includes a processor and a memory. A computer program is stored on the memory. When the computer program is run by the processor, a method for simulating the ocular fluorescence staining state after wearing a rigid contact lens as described in any one of claims 1 to 6 is executed.

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