Method and apparatus for measuring ocular axis length, electronic device, and storage medium

Abstract

Disclosed in the present application are a method and an apparatus for measuring an ocular axis length, an electronic device, and a storage medium. The method for measuring an ocular axis length comprises: acquiring at least one OCT image of an ocular tissue with an imaging range covering a range from a cornea to a retina of an eye to be measured; performing position recognition on the at least one OCT image to obtain a plurality of target positions, wherein the plurality of target positions comprise a corneal epithelial vertex position and a retinal macular fovea position; and determining an ocular axis length of said eye on the basis of the plurality of target positions.

Description

Axial length measurement method and device, electronic device and storage medium

[0001] The present application claims priority to the Chinese patent application No. 202411082924.0, filed on August 7, 2024, with the Chinese Patent Office, the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of optical coherence tomography, optical biometry, etc., for example, to an axial length measurement method and device, an electronic device and a storage medium. BACKGROUND

[0003] Optical coherence tomography (OCT) is a biomedical optical imaging technology that can be used for ophthalmic imaging. A human eye and an animal eye generally include an anterior segment and a posterior segment, and the axial length generally refers to the length from the corneal epithelial apex of the anterior segment to the macular fovea position of the posterior segment.

[0004] The axial length measurement method provided in the related art generally adjusts the position of a delay line to sequentially or simultaneously perform OCT imaging on the anterior segment and the posterior segment of the eye to be measured, and then splices the anterior segment OCT image and the posterior segment OCT image, and finally measures the axial length of the eye to be measured according to the spliced ophthalmic OCT image.

[0005] In the related art, the eye movement problem and the image splicing error problem can affect the axial length measurement. SUMMARY

[0006] The present application provides an axial length measurement method, device, electronic device and storage medium, which can overcome the influence of the eye movement problem and the image splicing error problem on the axial length measurement, thereby improving the accuracy of the axial length measurement.

[0007] The present application provides an axial length measurement method, comprising: acquiring at least one OCT image of eye tissue in a range from the cornea to the retina of an eye to be measured; performing position recognition on the at least one OCT image to obtain a plurality of target positions, wherein the plurality of target positions include a corneal epithelial apex position and a macular fovea position; and determining the axial length of the eye to be measured based on the plurality of target positions.

[0008] The application provides an axial length measurement device, comprising: an OCT image acquisition module configured to acquire at least one OCT image of eye tissue in a range from cornea to retina of an eye to be measured; a target position identification module configured to identify positions of the at least one OCT image to obtain a plurality of target positions, wherein the plurality of target positions comprise a corneal epithelial vertex position and a macular fovea position; and an axial length determination module configured to determine an axial length of the eye to be measured based on the plurality of target positions.

[0009] The application provides an electronic device, comprising: at least one processor; and a memory connected to the at least one processor in communication; wherein the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to execute the axial length measurement method.

[0010] The application provides a computer readable storage medium, which stores computer instructions for enabling a processor to execute the axial length measurement method. BRIEF DESCRIPTION OF DRAWINGS

[0011] Fig. 1 is a flowchart of an axial length measurement method according to an embodiment of the application;

[0012] Fig. 2 is a flowchart of another axial length measurement method according to an embodiment of the application;

[0013] Fig. 3A is a transverse eye OCT image according to an embodiment of the application;

[0014] Fig. 3B is a longitudinal eye OCT image corresponding to Fig. 3A;

[0015] Fig. 4A is another transverse eye OCT image according to an embodiment of the application;

[0016] Fig. 4B is a longitudinal eye OCT image corresponding to Fig. 4A;

[0017] Fig. 5 is a flowchart of an equivalent axial length measurement method according to an embodiment of the application;

[0018] Fig. 6 is a flowchart of a precise axial length measurement method according to an embodiment of the application;

[0019] Fig. 7 is a flowchart of an axial length measurement method with panoramic OCT image display according to an embodiment of the application;

[0020] Fig. 8 is a pupil diagram with OCT imaging direction display according to an embodiment of the application.

[0021] Fig. 9A is a transverse OCT image according to an embodiment of the present application;

[0022] Fig. 9B is an image region containing the location of the fovea of the macula of the retina, which is extracted based on Fig. 9A;

[0023] Fig. 9C is a panoramic OCT image, which is superimposed based on Fig. 9A and Fig. 9B;

[0024] Fig. 10 is a flowchart of an ocular axial length measurement method with image linkage display according to an embodiment of the present application;

[0025] Fig. 11 is a schematic diagram of linkage display of a pupil map and a panoramic OCT image according to an embodiment of the present application;

[0026] Fig. 12 is a transverse and longitudinal OCT partial image according to an embodiment of the present application;

[0027] Fig. 13 is a structural schematic diagram of an ocular axial length measurement device according to an embodiment of the present application;

[0028] Fig. 14 is a structural schematic diagram of an electronic device for implementing an ocular axial length measurement method according to an embodiment of the present application. DETAILED DESCRIPTION

[0029] The terms "first", "second", etc. in the specification and claims of the present application and in the above-described drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units shown in the embodiments of the present application can also include other processes, methods, systems, products and devices that are not clearly listed in the series of steps or units, or other steps or units inherent to these processes, methods, systems, products or devices. The acquisition, storage, use, processing, etc. of data in the technical solutions of the present application all comply with the relevant provisions of national laws and regulations.

[0030] FIG. 1 is a flowchart of an ocular axial length measurement method according to an embodiment of the present application. The embodiment of the present application is applicable to ocular axial length measurement in the case of panoramic OCT imaging of an eye. The method can be executed by an ocular axial length measurement device, which can be implemented in the form of hardware and / or software. The ocular axial length measurement device can be configured in an electronic device (e.g., a computer), which can be connected to an ophthalmic biometer and serve as a host (server) of the ophthalmic biometer.

[0031] In the embodiment of the present application, the server connected to the ophthalmic biometer can control the ophthalmic biometer to perform image acquisition (including pupil map acquisition and panoramic OCT imaging of an eye) and measure the ocular axial length of the eye based on the images acquired by the ophthalmic biometer. In the embodiment, panoramic OCT imaging of an eye by the ophthalmic biometer means that the device can obtain OCT imaging of eye tissues in the range from the cornea to the retina by a single shooting of the eye, i.e., the imaging range of each OCT image covers the range of eye tissues from the cornea to the retina of the eye to be measured, or in other words, the device can obtain OCT imaging of the anterior segment and the posterior segment of the eye by a single shooting of the eye, rather than separately performing OCT imaging of the anterior segment and the posterior segment of the eye or simultaneously performing OCT imaging of the anterior segment and the posterior segment of the eye, and then splicing the OCT imaging of the anterior segment and the posterior segment of the eye to obtain panoramic OCT imaging of eye tissues in the range from the cornea to the retina.

[0032] As shown in FIG. 1, the method can include operations S110-S130.

[0033] In operation S110, at least one OCT image is acquired, which covers the imaging range of eye tissues in the range from the cornea to the retina of the eye to be measured.

[0034] In operation S120, position recognition is performed on the at least one OCT image to obtain a plurality of target positions, wherein the plurality of target positions at least include the corneal epithelial vertex position and the macular fovea position of the retina.

[0035] In operation S130, the ocular axial length of the eye to be measured is determined based on the plurality of target positions.

[0036] In one embodiment, when the axial length of the eye to be measured is measured, only one panoramic OCT image can be taken for the axial length measurement, which can be affected by accidental factors (such as the pupil of the person to be measured being blocked or poor fixation, etc.), resulting in poor image quality and affecting the axial length measurement result. In another embodiment, when the axial length of the eye to be measured is measured, a set of panoramic OCT images (including multiple panoramic OCT images) can also be taken at one time for axial length measurement to avoid the situation of being affected by accidental factors when only one panoramic OCT image is taken, resulting in inaccurate axial length measurement results. Therefore, in the embodiments of the present application, at least one panoramic OCT image obtained by the ophthalmic biometer when taking the eye to be measured at one time can be obtained for measuring the axial length of the eye to be measured at operation S110.

[0037] The axial length of the eye refers to the length of the eye (human eye or animal eye) from the corneal epithelial vertex position to the macular fovea position of the retina. Therefore, in the embodiments of the present application, the position recognition of the panoramic OCT image obtained at operation S110 can be performed at operation S120, and the axial length of the eye to be measured can be calculated based on the target position including at least the corneal epithelial vertex position and the macular fovea position of the retina obtained from the same panoramic OCT image. In one embodiment of the present application, the position recognition of all panoramic OCT images obtained at operation S110 can be performed for axial length measurement at operation S120. In another embodiment of the present application, the high-quality images can be selected from all panoramic OCT images obtained at operation S110 at operation S120, and the position recognition of the selected high-quality images can be performed for axial length measurement.

[0038] At operation S120, for each panoramic OCT image used for axial length measurement, the position recognition of the image can be performed by using a shortest path algorithm such as Dijkstra algorithm, so as to obtain the target position in each panoramic OCT image.

[0039] In one embodiment, in operation S130, for each panoramic OCT image used for measurement of the axial length of the eye, the axial length of the eye to be measured can be calculated only according to the corneal epithelial vertex position and the retinal macular fovea position of each panoramic OCT image obtained in operation S120, and the average refractive index (equivalent refractive index) of the ocular tissue between the corneal epithelium and the retina and the axial resolution of the image. In another embodiment, in operation S120, the position identification is performed for each panoramic OCT image used for measurement of the axial length of the eye, and the target positions obtained can include not only the corneal epithelial vertex position and the retinal macular fovea position, but also specific positions of other ocular tissues between the cornea and the retina. In this case, in operation S130, the axial length of the eye to be measured can also be more accurately calculated according to the corneal epithelial vertex position and the retinal macular fovea position, and the specific positions of other ocular tissues between the cornea and the retina, and the actual refractive index of each layer of ocular tissue between the corneal epithelium and the retina and the axial resolution of the image.

[0040] In the related art, when measuring the axial length of the eye, one scheme is to first obtain the anterior segment OCT image of the eye to be measured by single-shot imaging, and then obtain the posterior segment OCT image of the eye to be measured by single-shot imaging (or first obtain the posterior segment OCT image of the eye to be measured by single-shot imaging, and then obtain the anterior segment OCT image of the eye to be measured by single-shot imaging), and then splice the anterior segment OCT image and the posterior segment OCT image obtained by single-shot imaging into a “panoramic OCT image” for axial length measurement. In this scheme, since the anterior segment OCT image and the posterior segment OCT image are obtained by single-shot imaging, there is a time difference between the two separate shootings, and in this case, the corneal epithelial vertex position and the retinal macular fovea position in the panoramic OCT image spliced from the two separate shootings are easily misaligned due to eye blinking of the subject or eye movement of the subject, thereby causing inaccurate axial length measurement. In addition, in this scheme, the image splicing operation itself can also introduce errors, affecting the image quality and thus the accuracy of the axial length measurement result.

[0041] In the related art, when measuring the axial length of the eye, another scheme is to first separately take OCT images of the anterior segment and the posterior segment of the eye to be measured at the same time, and then splice the anterior segment OCT image and the posterior segment OCT image obtained by separate shooting into a panoramic OCT image for axial length measurement. In this scheme, although the anterior segment OCT image and the posterior segment OCT image are separately imaged at the same time, there is no problem of time difference, and further, there is no problem that the position of the corneal epithelial apex and the position of the macular fovea in the panoramic OCT image cannot be aligned due to the blinking of the person to be measured or the eye movement of the person to be measured. However, this scheme still needs to splice the two OCT images (anterior segment OCT image and posterior segment OCT image) into a "panoramic OCT image" first, and then measure the axial length of the eye based on the "panoramic OCT image" spliced. Therefore, this scheme still has the error problem introduced by the image splicing operation, and thus has the problem of inaccurate axial length measurement.

[0042] Different from the related art, the technical scheme provided in the embodiments of the present application, when measuring the axial length of the eye, since the OCT images obtained by single shooting are all panoramic OCT images whose imaging range covers the anterior segment tissue and the posterior segment tissue of the eye, there is no time difference problem and its influence problem caused by separately imaging the anterior segment and the posterior segment, and there is also no error problem introduced by image splicing. Therefore, the embodiments of the present application realize the true sense of axial length measurement of the eye through true panoramic OCT imaging of the eye, and can improve the accuracy of axial length measurement of the eye.

[0043] As described above, in order to improve the accuracy of the measurement result, multiple panoramic OCT images of the eye can be taken at one time for axial length measurement. However, in actual operation, the person to be measured may blink or have poor fixation, etc., so that one or more images with poor quality appear in the multiple panoramic OCT images taken, and further affect the accuracy of the measurement result. Therefore, in an embodiment of the present application, in order to further improve the accuracy of the measurement result, for all panoramic OCT images obtained in operation S110, high-quality images can be first selected from them, and then the selected high-quality images are subjected to position recognition for axial length measurement.

[0044] As shown in FIG. 2, the method can include operations S110, S221, S222 and S130.

[0045] In operation S110, at least one OCT image whose imaging range covers the eye tissue in the cornea to retina range of the eye to be measured is obtained.

[0046] Operation S221, optical axis recognition is performed on the at least one OCT image obtained in operation S110 to obtain at least one target OCT image containing the optical axis in the at least one OCT image.

[0047] Operation S222, position recognition is performed on the at least one target OCT image obtained in operation S221 to obtain a plurality of target positions, wherein the plurality of target positions at least include a corneal epithelial vertex position and a retinal macular fovea position.

[0048] Operation S130, based on the plurality of target positions, the axial length of the eye to be measured is determined.

[0049] In the embodiments of the present application, operation S110 and S130 correspond to operation S110 and S130 shown in FIG. 1 respectively, and the same, and the embodiments will not be repeated here.

[0050] When an ophthalmic panoramic OCT image is taken using an ophthalmic biometer, if the person to be measured blinks or has poor fixation, the optical axis cannot be seen in the panoramic OCT image taken. On the contrary, if the person to be measured does not blink or has no poor fixation during the shooting process, the optical axis can be seen in the panoramic OCT image taken. Therefore, in the embodiments of the present application, when selecting images with high quality, optical axis recognition can be performed on the at least one panoramic OCT image obtained in operation S110 to obtain the image containing the optical axis as the target OCT image for axial length measurement. For the image not containing the optical axis, it is discarded in the axial length measurement. That is, in operation S222, only the position recognition is performed on all the target OCT images obtained in operation S221 to obtain the target positions for determining the axial length of the eye to be measured.

[0051] For example, it is assumed that a set of captured panoramic OCT images includes a transverse eye OCT image as shown in FIG. 3A and a longitudinal eye OCT image as shown in FIG. 3B, where the imaging directions of the transverse eye OCT image and the longitudinal eye OCT image are perpendicular to each other, and it can be seen from the figures that both the transverse eye OCT image and the longitudinal eye OCT image contain an optical axis, in which case both of the OCT images are considered to be high-quality images, and the positions of the corneal epithelial apex and the retinal macular fovea in the images are aligned, and the OCT images can be retained for subsequent axial length calculation. For example, it is assumed that another set of captured panoramic OCT images includes a transverse eye OCT image as shown in FIG. 4A and a longitudinal eye OCT image as shown in FIG. 4B, and it can be seen from the figures that the transverse eye OCT image does not contain an optical axis, in which case the transverse eye OCT image is considered to be a low-quality image, and the positions of the corneal epithelial apex and the retinal macular fovea in the image are not aligned, and the OCT image can be removed and no longer used for subsequent axial length calculation.

[0052] In the embodiments of the present application, the optical axis recognition can be used to screen high-quality panoramic OCT images containing an optical axis and remove low-quality panoramic OCT images without an optical axis, and finally only the high-quality panoramic OCT images are used for axial length measurement. Therefore, the embodiments of the present application can further improve the accuracy of axial length measurement.

[0053] In addition, in the embodiments of the present application, if the number of target OCT images containing an optical axis obtained after the optical axis recognition of all the OCT images obtained in operation S110 is small, it indicates that the overall quality of the set of panoramic OCT images captured this time is poor, and in this case, if the set of images is still used for axial length measurement, the accuracy of the measurement result cannot be ensured.

[0054] Therefore, in an optional embodiment of the present application, if the number of target OCT images obtained after the optical axis recognition is small, the user (doctor) can also be prompted to re-shoot a set of panoramic OCT images for axial length measurement. For example, the method can further include: in response to the number of at least one target OCT image obtained in operation S221 being less than a preset value, prompting the user to re-shoot a set of OCT images for axial length measurement for the eye to be measured.

[0055] In the embodiments of the present application, the number of OCT images that need to be captured in a set of panoramic OCT images and the above-mentioned preset value can be self-defined according to experimental or statistical values, which are not limited in the present embodiments.

[0056] Exemplarily, the eye to be measured can be multi-azimuth panoramic OCT imaged in 12 different imaging directions, so as to obtain a group of images containing 12 panoramic OCT images. If it is found after screening based on the optical axis that the number of OCT images containing the optical axis in the group of panoramic OCT images is less than 5, it is considered that the overall quality of the OCT images taken this time is poor, which may lead to inaccurate subsequent axial length measurement, and therefore the user can be prompted in the interactive interface of the server connected with the ophthalmic biometer to re-shoot a group of OCT images for axial length measurement of the eye to be measured, so as to improve the accuracy of the axial length measurement.

[0057] In an optional embodiment, the position recognition on the at least one target OCT image obtained in operation S221 to obtain a plurality of target positions can include: for each of the at least one target OCT image, performing eye tissue recognition (recognizing each layer of eye tissue) based on the OCT image, determining the corneal epithelial boundary and the retinal pigment epithelial boundary; performing optical axis recognition based on the OCT image, and determining the first intersection Q1 of the optical axis and the corneal epithelial boundary, and the second intersection Q5 of the optical axis and the retinal pigment epithelial boundary. Wherein the position corresponding to the first intersection Q1 is the corneal epithelial vertex position, and the position corresponding to the second intersection Q5 is the retinal macular fovea position.

[0058] In the embodiments of the present application, by performing eye tissue recognition and optical axis recognition on each target OCT image, the corneal epithelial vertex position and the retinal macular fovea position can be accurately located to assist in improving the accuracy of axial length measurement.

[0059] In another optional embodiment, the position recognition on the at least one target OCT image obtained in operation S221 to obtain a plurality of target positions can include: for each of the at least one target OCT image, performing eye tissue recognition based on the OCT image, determining the corneal epithelial boundary, the corneal endothelial boundary, the anterior lens surface, the posterior lens surface and the retinal pigment epithelial boundary; performing optical axis recognition based on the OCT image, and determining the first intersection Q1 of the optical axis and the corneal epithelial boundary, the fifth intersection Q5 of the optical axis and the corneal endothelial boundary, the third intersection Q3 of the optical axis and the anterior lens surface, the fourth intersection Q4 of the optical axis and the posterior lens surface, and the second intersection Q2 of the optical axis and the retinal pigment epithelial boundary. The position corresponding to the first intersection Q1 can be determined as the corneal epithelial vertex position, the position corresponding to the fifth intersection Q5 can be determined as the corneal endothelial intersection position, the position corresponding to the third intersection Q3 can be determined as the anterior lens surface intersection position, the position corresponding to the fourth intersection Q4 can be determined as the posterior lens surface intersection position, and the position corresponding to the second intersection Q2 can be determined as the retinal macular fovea position.

[0060] In the embodiments of the present application, by performing eye tissue recognition and optical axis recognition on each target OCT image, the corneal epithelial vertex position, the corneal endothelial intersection position, the lens anterior surface intersection position, the lens posterior surface intersection position and the macular fovea position can be accurately located to assist in improving the accuracy of the axial length measurement in the axial length precise model calculation.

[0061] In addition, in other optional embodiments, when the position recognition is performed on the at least one OCT image to obtain a plurality of target positions in operation S120, each OCT image therein can also be processed by using the similar method provided in the above embodiments, which will not be described herein again. In the embodiments of the present application, by performing eye tissue recognition and optical axis recognition on each OCT image, the corneal epithelial vertex position and the macular fovea position (or the corneal epithelial vertex position, the corneal endothelial intersection position, the lens anterior surface intersection position, the lens posterior surface intersection position and the macular fovea position) can be accurately located to assist in improving the accuracy of the axial length measurement.

[0062] In an embodiment of the present application, an equivalent model calculation method of the axial length is provided. By using the equivalent model calculation method of the axial length, the corneal endothelial intersection position, the lens anterior surface intersection position and the lens posterior surface intersection position do not need to be located, but only the corneal epithelial vertex position and the macular fovea position are located, and then the axial length can be calculated by using the equivalent model of the axial length.

[0063] In another embodiment of the present application, a precise model calculation method of the axial length is provided. By using the precise model calculation method of the axial length, the corneal epithelial vertex position, the corneal endothelial intersection position, the lens anterior surface intersection position, the lens posterior surface intersection position and the macular fovea position can be located for the precise model calculation of the axial length.

[0064] For the equivalent model calculation method of the axial length, as shown in FIG. 5, the method can include operations S110, S120 and S531.

[0065] In operation S110, at least one OCT image of the eye tissue in the range from the cornea to the retina of the to-be-measured eye covered by the imaging range is acquired.

[0066] In operation S120, the position recognition is performed on the at least one OCT image acquired in operation S110 to obtain a plurality of target positions, wherein the plurality of target positions at least include the corneal epithelial vertex position and the macular fovea position.

[0067] In operation S531, the axial length of the to-be-measured eye is determined based on the corneal epithelial vertex position and the macular fovea position.

[0068] In the embodiments of the present application, operations S110 and S120 correspond to operations S110 and S120 shown in FIG. 1 respectively, and the embodiments will not be described here again.

[0069] In an optional embodiment, operation S531 can include: calculating an initial distance L0 between the corneal epithelial vertex position and the retinal macular fovea position; and obtaining the equivalent axial length of the to-be-measured eye based on the initial distance L0, the image axial resolution, and the equivalent refractive index of the ocular tissue.

[0070] Illustratively, the initial distance L0 between the two positions can be calculated according to the pixel coordinates of the retinal macular fovea position and the pixel coordinates of the corneal epithelial vertex position, and then the initial distance L0 is multiplied by the image axial resolution to obtain the optical length of the eye axis, and then the optical length of the eye axis is converted based on the equivalent refractive index of the ocular tissue, and finally the equivalent axial length of the to-be-measured eye is obtained. For example, the calculated optical length of the eye axis can be divided by the equivalent refractive index of the ocular tissue to obtain the equivalent axial length of the to-be-measured eye.

[0071] In the embodiments of the present application, only the corneal epithelial vertex position and the retinal macular fovea position are located, and the equivalent calculation of the axial length of the eye can be realized, which simplifies the calculation method of the axial length of the eye and can improve the measurement efficiency of the axial length of the eye.

[0072] For the accurate model calculation method of the axial length of the eye, as shown in FIG. 6, the method can include operations S110, S120 and S631.

[0073] Operation S110: acquiring at least one OCT image of the ocular tissue in the range from the cornea to the retina of the to-be-measured eye covered by the imaging range.

[0074] Operation S120: performing position recognition on the at least one OCT image acquired in operation S110 to obtain a plurality of target positions, wherein the plurality of target positions at least include the corneal epithelial vertex position, the retinal macular fovea position, the corneal endothelial intersection position, the anterior lens surface intersection position, and the posterior lens surface intersection position.

[0075] Operation S631: determining the axial length of the to-be-measured eye based on the corneal epithelial vertex position, the corneal endothelial intersection position, the anterior lens surface intersection position, the posterior lens surface intersection position, and the retinal macular fovea position.

[0076] In the embodiments of the present application, operations S110 and S120 correspond to operations S110 and S120 shown in FIG. 1 respectively, and the embodiments will not be described here again.

[0077] Further, in the embodiments of the present application, in operation S120, the eye tissue of each OCT image obtained in operation S110 can be recognized by an image recognition algorithm, so as to recognize the corneal epithelial boundary, the subcorneal epithelial boundary, the anterior lens surface, the posterior lens surface and the retinal pigment epithelial boundary, and to perform optical axis recognition on each OCT image, and to determine the first intersection point Q1 of the optical axis and the corneal epithelial boundary, the fifth intersection point Q5 of the optical axis and the subcorneal epithelial boundary, the third intersection point Q3 of the optical axis and the anterior lens surface, the fourth intersection point Q4 of the optical axis and the posterior lens surface, and the second intersection point Q2 of the optical axis and the retinal pigment epithelial boundary, the position corresponding to the first intersection point Q1 can be determined as the corneal epithelial vertex position, the position corresponding to the fifth intersection point Q5 can be determined as the corneal endothelial intersection position, the position corresponding to the third intersection point Q3 can be determined as the anterior lens surface intersection position, the position corresponding to the fourth intersection point Q4 can be determined as the posterior lens surface intersection position, and the position corresponding to the second intersection point Q2 is the retinal macular fovea position.

[0078] In an optional embodiment, operation S631 can include: calculating a first distance between the corneal epithelial vertex position and the corneal endothelial intersection position, and obtaining a length L1 of a first ocular axis substructure based on the first distance, the image axial resolution and the corneal refractive index; calculating a second distance between the corneal endothelial intersection position and the anterior lens surface intersection position, and obtaining a length L2 of a second ocular axis substructure based on the second distance, the image axial resolution and the anterior chamber refractive index; calculating a third distance between the anterior lens surface intersection position and the posterior lens surface intersection position, and obtaining a length L3 of a third ocular axis substructure based on the third distance, the image axial resolution and the lens refractive index; calculating a fourth distance between the posterior lens surface intersection position and the retinal macular fovea position, and obtaining a length L4 of a fourth ocular axis substructure based on the fourth distance, the image axial resolution and the vitreous refractive index; and determining the ocular axis length of the to-be-measured eye based on the lengths of the first to fourth ocular axis substructures.

[0079] In this embodiment, the calculation methods of the first distance to the fourth distance are similar to the calculation method of the initial distance L0 in the foregoing embodiment, which will not be repeated here. In addition, in this embodiment, the calculation method of each of the length L1 of the first ocular axis substructure to the length L4 of the fourth ocular axis substructure is similar to the calculation method of the equivalent ocular axis length in the foregoing embodiment. For example, when calculating the length L1 of the first ocular axis substructure, the product of the first distance and the image axial resolution can be calculated first to obtain the optical length of the first ocular axis substructure, and then the optical length of the first ocular axis substructure is divided by the refractive index of the cornea to obtain the length L1 of the first ocular axis substructure. The lengths of other ocular axis substructures can also be calculated in a similar manner, except that different refractive indices of the ocular axis substructures are used in the length calculation of the corresponding ocular axis substructure. The embodiments of the present application will not be repeated here.

[0080] In the embodiments of the present application, the positions of the corneal epithelial apex, the corneal endothelial intersection, the lens anterior surface intersection, the lens posterior surface intersection, and the macular fovea of the retina need to be located to achieve accurate calculation of the ocular axis length. In this embodiment, although the calculation method of the accurate ocular axis length is not as simple as the calculation method of the equivalent ocular axis length, the accurate model calculation method of the ocular axis length can improve the measurement accuracy and measurement accuracy of the ocular axis length.

[0081] In one embodiment, the ocular axis length measurement method can include operations S740-S760 as shown in FIG. 7 in addition to operations S110-S130 as shown in FIG. 1.

[0082] In the embodiments of the present application, operations S110-S130 correspond to operations S110-S130 in the embodiment as shown in FIG. 1, which will not be repeated here.

[0083] Operation S740 displays a transverse OCT image and / or a longitudinal OCT image in at least one OCT image obtained in operation S110.

[0084] Operation S750 crops a preset image region containing the macular fovea of the retina from the displayed OCT image.

[0085] Operation S760 enlarges the cropped preset image region by a preset ratio and then superimposes and displays it in a target region in the currently displayed OCT image.

[0086] As described above, in the embodiments of the present application, a plurality of OCT imaging directions can be preset, for example, 12 imaging directions can be set in the pupil diagram as shown in FIG. 8, which include horizontal imaging directions (lateral imaging directions) and vertical imaging directions (longitudinal imaging directions). When the axial length of the eye to be measured needs to be measured, the ophthalmic biometer can be controlled to collect a panoramic OCT image in each of the 12 imaging directions, so as to obtain a group of images containing 12 panoramic OCT images, wherein a lateral OCT image can be obtained in the lateral imaging direction, and a longitudinal OCT image can be obtained in the longitudinal imaging direction.

[0087] Therefore, in one embodiment, for example, in operation S740, for the at least one OCT image obtained in operation S110, the lateral OCT image and / or the longitudinal OCT image in the at least one OCT image currently obtained can be displayed in real time in the display interface of the server connected with the ophthalmic biometer, so as to intuitively display the panoramic OCT image of the eye to be measured in the specified imaging direction to the user in the image collection, thereby assisting the user to collect images with higher quality, or facilitating the user to preliminarily judge whether the collected images meet the use requirements. In one embodiment, considering the limitation of the display interface, only the lateral OCT image can be displayed. In the present embodiment, operations S740-S760 can display the relevant panoramic OCT image in real time, so as to dynamically panoramic visualize the OCT imaging of the axial length.

[0088] The premise of accurately measuring the axial length is to collect a panoramic OCT image with higher quality, and the panoramic OCT image with higher quality not only requires the optical axis to appear in the image, but also requires the optical axis to pass through the corneal epithelial vertex and the macular fovea position at the same time. Therefore, in the present embodiment of the present application, in the OCT image displayed in operation S740, the image region containing the macular fovea position can be intercepted, and the image region can be enlarged according to a preset ratio and then superimposed and displayed in the target region of the currently displayed OCT image, so as to enable the user to observe and judge in real time whether the optical axis in the collected image passes through the corneal epithelial vertex and the macular fovea position at the same time. If the optical axis in the panoramic OCT image passes through the corneal epithelial vertex and the macular fovea position at the same time, it indicates that the corneal epithelial vertex and the macular fovea position of the eye to be measured are aligned.

[0089] For example, the OCT image shown in FIG. 9A is a transverse OCT image collected for the eye to be measured; the image region shown in FIG. 9B is an image region containing the location of the fovea of the retina, which is cropped from the transverse OCT image shown in FIG. 9A; and the OCT image shown in FIG. 9C is a panoramic OCT image obtained by superimposing the image region shown in FIG. 9B in the transverse OCT image shown in FIG. 9A after magnifying the image region by a preset ratio. It can be directly observed from the panoramic OCT image shown in FIG. 9C that the current optical axis passes through the location of the fovea of the retina, and thus the panoramic OCT image can be used as a higher-quality OCT image for measuring the axial length of the eye.

[0090] In an optional embodiment, the operation S760 of cropping a preset image region containing the fovea of the retina from the displayed OCT image can include: cropping a middle image region from the displayed OCT image to obtain a retinal OCT image; performing brightness identification on the retinal OCT image to determine a position of maximum brightness; cropping a target image region from the retinal OCT image based on the position of maximum brightness and a preset display range; and using the cropped target image region as the preset image region containing the fovea of the retina.

[0091] In this embodiment, after obtaining the retinal OCT image, the average brightness of each row of pixels in the retinal OCT image can be determined, and then the position of maximum pixel brightness in the retinal OCT image can be found using the sliding window method. Based on the preset display range, a target image region is cropped from the retinal OCT image with the position of maximum pixel brightness as the center. Then, the cropped target image region is used as the preset image region containing the fovea of the retina, and the target image region is magnified by a preset ratio and superimposed and displayed in a target region in the currently displayed OCT image.

[0092] In the embodiments of the present application, the target image region containing the fovea of the retina in the panoramic OCT image is accurately positioned and cropped, and the target image region is magnified and superimposed and displayed in a target region in the panoramic OCT image, which can facilitate the user to observe and determine in real time whether the optical axis in the collected image passes through the vertex of the corneal epithelium and the location of the fovea of the retina at the same time.

[0093] In an embodiment, the axial length measurement method can include operations S1040-S1060 shown in FIG. 10 in addition to operations S110-S130 shown in FIG. 1.

[0094] In the embodiments of the present application, operations S110-S130 correspond to or are similar to operations S110-S130 in the embodiment shown in FIG. 1, and thus will not be described here again.

[0095] Operation S1040, the pupil diagram of the eye to be measured is acquired and displayed.

[0096] Operation S1050, the imaging direction of each OCT image acquired in operation S110 is determined.

[0097] Operation S1060, the imaging direction of each OCT image determined in operation S1050 is superimposed and displayed in the displayed pupil diagram.

[0098] In the embodiments of the present application, the pupil diagram of the eye to be measured can be acquired by the ophthalmic biometer. Therefore, in operation S1040, the ophthalmic biometer can be controlled to acquire the pupil diagram of the eye to be measured and display the currently acquired pupil diagram in real time on the server side.

[0099] In addition, as described above, in the embodiments of the present application, a plurality of OCT imaging directions can be set in advance, for example, 12 imaging directions can be set in the pupil diagram as shown in FIG. 8, which include horizontal imaging directions (lateral imaging directions) and vertical imaging directions (longitudinal imaging directions). When the axial length of the eye to be measured needs to be measured, the ophthalmic biometer can be controlled to acquire a panoramic OCT image in each of the 12 imaging directions, so as to obtain a group of images containing 12 panoramic OCT images. Each image in the image group is stored in association with its imaging direction. Therefore, in operation S1050 and operation S1060, the imaging direction of each OCT image acquired in operation S110 can be determined according to the association storage relationship between each image in the image group and its imaging direction, and the imaging direction of each OCT image determined in operation S1050 can be superimposed and displayed in the currently displayed pupil diagram. For example, each imaging direction can be displayed as a line, and the direction of the line represents the imaging direction.

[0100] In the embodiments of the present application, by acquiring and displaying the pupil diagram of the eye to be measured in real time during the shooting of the panoramic OCT image and displaying the imaging direction of the panoramic OCT image in the pupil diagram in real time, the user can conveniently view and understand the imaging direction of the panoramic OCT image in real time.

[0101] In an optional embodiment, for each imaging direction, in response to the current imaging direction being triggered, the current imaging direction can be specially displayed, for example, by changing the thickness or color or shape of the line representing the imaging direction, and the OCT image corresponding to the current imaging direction is displayed in linkage.

[0102] In this embodiment, the pupil diagram, the imaging direction and the panoramic OCT image corresponding to the imaging direction are displayed in linkage, so that the user can conveniently view and understand the image quality of the panoramic OCT image in each imaging direction, and then determine whether the image needs to be re-shot to obtain high-quality OCT image to assist the doctor in accurately judging and evaluating the axial length of the patient's eye.

[0103] Exemplarily, as shown in FIG. 11, the display interface displays the pupil diagram and the panoramic OCT image in linkage, and the panoramic OCT image is a transverse panoramic OCT image. When the user triggers the transverse imaging direction (the imaging direction represented by line a) in the pupil diagram, the line a changes color and adds an arrow, and the panoramic OCT image display area displays the transverse panoramic OCT image.

[0104] In an optional embodiment, the transverse imaging direction and the longitudinal imaging direction can also be specially displayed in the pupil diagram, and the transverse OCT image corresponding to the transverse imaging direction or the whole or part of the transverse OCT image is displayed in linkage; and the longitudinal OCT image corresponding to the longitudinal imaging direction or the whole or part of the longitudinal OCT image is displayed in linkage.

[0105] Exemplarily, as shown in FIG. 12, the transverse OCT partial image (left image) and the longitudinal OCT partial image (right image) displayed in the display interface can be images displayed in linkage with the pupil diagram shown in FIG. 11. In this embodiment, through the linkage display, when the panoramic OCT image is shot, the user can conveniently preview and observe whether the optical axis appears in the transverse OCT partial image and the longitudinal OCT partial image. If the optical axis appears in the OCT partial images in both transverse and longitudinal directions, it means that the high-quality panoramic OCT image can be obtained by pressing the OCT image shooting key in this case. Therefore, the dynamic visualization linkage display scheme provided in this embodiment can guide the user to collect the panoramic OCT image with higher quality, thereby providing image support for subsequent accurate measurement of the axial length of the eye.

[0106] FIG. 13 is a structural schematic diagram of an axial length measurement device provided in an embodiment of the present application. As shown in FIG. 13, the device comprises: an OCT image acquisition module 1310 configured to acquire at least one OCT image of eye tissue in a range from cornea to retina of a to-be-measured eye; a target position identification module 1320 configured to identify positions of the at least one OCT image to obtain a plurality of target positions, wherein the plurality of target positions at least include a corneal epithelial vertex position and a macular fovea position; and an axial length determination module 1330 configured to determine an axial length of the to-be-measured eye based on the plurality of target positions.

[0107] In some optional embodiments, the target position identifying module 1320 includes: an optical axis identifying unit configured to perform optical axis identification on the at least one OCT image to obtain at least one target OCT image containing an optical axis in the at least one OCT image; and a position identifying unit configured to perform position identification on the at least one target OCT image to obtain the plurality of target positions.

[0108] In some optional embodiments, the axial length measuring device further includes: an eye re-shooting module configured to, in response to the number of the at least one target OCT image being less than a preset value, prompt a user to re-shoot a set of OCT images for axial length measurement of the eye to be measured.

[0109] In some optional embodiments, the position identifying unit is configured to: for each OCT image in the at least one target OCT image, perform eye tissue identification based on the OCT image to determine a corneal epithelium boundary and a retinal pigment epithelium boundary; perform optical axis identification based on the OCT image to determine a first intersection point of an optical axis and the corneal epithelium boundary and a second intersection point of the optical axis and the retinal pigment epithelium boundary; and wherein the position corresponding to the first intersection point is the corneal epithelium vertex position and the position corresponding to the second intersection point is the retinal macular fovea position.

[0110] In some optional embodiments, the axial length determining module 1330 includes: an axial length equivalent calculating unit configured to determine the axial length of the eye to be measured based on the corneal epithelium vertex position and the retinal macular fovea position.

[0111] In some optional embodiments, the axial length equivalent calculating unit is configured to: calculate an initial distance between the corneal epithelium vertex position and the retinal macular fovea position; and obtain an equivalent axial length of the eye to be measured based on the initial distance, an image axial resolution, and an equivalent refractive index of eye tissue.

[0112] In some optional embodiments, the plurality of target positions further include: a corneal endothelium intersection position, a lens anterior surface intersection position, and a lens posterior surface intersection position; and wherein the axial length determining module 1330 includes: an axial length accurate calculating unit configured to determine the axial length of the eye to be measured based on the corneal epithelium vertex position, the corneal endothelium intersection position, the lens anterior surface intersection position, the lens posterior surface intersection position, and the retinal macular fovea position.

[0113] In some optional embodiments, the axial length calculating unit is configured to: calculate a first distance between the corneal epithelium vertex position and the corneal endothelium intersection position, and obtain a length of a first ocular axial substructure based on the first distance, an axial resolution of the image, and a corneal refractive index; calculate a second distance between the corneal endothelium intersection position and the lens anterior surface intersection position, and obtain a length of a second ocular axial substructure based on the second distance, the axial resolution of the image, and an anterior chamber refractive index; calculate a third distance between the lens anterior surface intersection position and the lens posterior surface intersection position, and obtain a length of a third ocular axial substructure based on the third distance, the axial resolution of the image, and a lens refractive index; calculate a fourth distance between the lens posterior surface intersection position and the macular fovea position, and obtain a length of a fourth ocular axial substructure based on the fourth distance, the axial resolution of the image, and a vitreous refractive index; and determine the axial length of the eye to be measured based on the lengths of the first ocular axial substructure to the fourth ocular axial substructure.

[0114] In some optional embodiments, the axial length measuring device further comprises: an OCT image display module configured to display a transverse OCT image and / or a longitudinal OCT image in the at least one OCT image; an image region intercepting module configured to intercept a preset image region containing the macular fovea from the displayed OCT image; and a magnified superimposition module configured to superimpose and display the intercepted preset image region in a target region in the currently displayed OCT image at a preset magnification.

[0115] In some optional embodiments, the image region intercepting module is configured to: intercept a middle image region from the displayed OCT image to obtain a retinal OCT image; perform brightness identification on the retinal OCT image to determine a position of maximum brightness; intercept a target image region from the retinal OCT image based on the position of maximum brightness and a preset display range; and use the intercepted target image region as the preset image region containing the macular fovea.

[0116] In some optional embodiments, the axial length measuring device further comprises: a pupil map obtaining module configured to obtain and display a pupil map of the eye to be measured; an imaging direction determining module configured to determine an imaging direction of each OCT image in the at least one OCT image; and an imaging direction superimposition display module configured to superimpose and display the imaging direction of each OCT image in the displayed pupil map.

[0117] In some optional embodiments, the ocular axial length measuring device further comprises a linkage display module configured to, for each imaging direction, in response to the current imaging direction being triggered, specially display the current imaging direction and linkage display the OCT image corresponding to the current imaging direction.

[0118] In some optional embodiments, the linkage display module is further configured to: specially display the transverse imaging direction and the longitudinal imaging direction; linkage display all or part of the OCT image corresponding to the transverse imaging direction; and linkage display all or part of the OCT image corresponding to the longitudinal imaging direction.

[0119] The ocular axial length measuring device provided by the embodiments of the present application can perform the ocular axial length measuring method provided by any of the embodiments of the present application, and has the corresponding function modules and beneficial effects of performing the method.

[0120] FIG. 14 shows a structural schematic diagram of an electronic device 10 that can be used to implement embodiments of the present application. The electronic device is intended to represent a variety of forms of digital computers, such as laptops, desktops, workstations, personal digital assistants, servers, blade servers, mainframes, and other appropriate computers. The electronic device can also represent a variety of forms of mobile devices, such as personal digital assistants, cellular telephones, smart phones, wearable devices (such as headsets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions, are meant to be examples only, and are not intended to limit the implementations of the present application described and / or claimed in this document.

[0121] As shown in FIG. 14, the electronic device 10 includes at least one processor 11, and a memory, such as a Read-Only Memory (ROM) 12, a Random Access Memory (RAM) 13, etc., which are in communication with the at least one processor 11, wherein the memory stores a computer program that can be executed by the at least one processor. The processor 11 can perform various appropriate actions and processes according to the computer program stored in the ROM 12 or loaded from the storage unit 18 into the RAM 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An Input / Output (I / O) interface 15 is also connected to the bus 14.

[0122] A plurality of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, and the like; an output unit 17, such as various types of displays, speakers, and the like; a storage unit 18, such as a magnetic disk, an optical disk, and the like; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, and the like. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network, such as the Internet, and / or various telecommunication networks.

[0123] The processor 11 can be various general and / or special-purpose processing components with processing and computing capabilities. Some examples of the processor 11 include a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, and the like. The processor 11 performs various methods and processes described above, such as an axial length measurement method, which includes: acquiring at least one OCT image of ocular tissue in a range from a cornea to a retina of an eye to be measured, which is covered by an imaging range; performing position recognition on the at least one OCT image to obtain a plurality of target positions, wherein the plurality of target positions at least include a corneal epithelial apex position and a retinal macular fovea position; and determining an axial length of the eye to be measured based on the plurality of target positions.

[0124] In some embodiments, the axial length measurement method can be implemented as a computer program, which is tangibly embodied in a computer-readable storage medium, such as the storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed onto the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded onto the RAM 13 and executed by the processor 11, one or more steps of the axial length measurement method described above can be performed. Alternatively, in other embodiments, the processor 11 can be configured to perform the axial length measurement method by any other appropriate means, such as by means of firmware.

[0125] Various implementations of the systems and techniques described above can be realized in digital electronic circuitry, integrated circuitry, a Field Programmable Gate Array (FPGA), an Application Specific Integrated Circuit (ASIC), an Application Specific Standard Parts (ASSP), a System on Chip (SOC), a Complex Programmable Logic Device (CPLD), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include implementation in one or more computer programs that are executable and / or interpretable on a programmable system including at least one programmable processor, which can be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device.

[0126] Computer programs implementing methods of the present application can be written in any combination of one or more programming languages. These computer programs can be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the computer program, when executed by the processor of the machine, implements the functions / acts specified in the flow diagrams and / or block diagrams. The computer program can be executed entirely on a machine, partially on a machine, partially on a machine as part of a standalone software package, partially on a machine and partially on a remote machine or entirely on a remote machine or server.

[0127] In the context of this application, a computer-readable storage medium can be a tangible medium that can contain or store computer programs for use by or in connection with an instruction execution system, apparatus, or device. Computer-readable storage media can include electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium can be a machine-readable signal medium. More specific examples of a machine-readable storage medium will include one or more lines of a program of instructions in a transitory signal, a portable computer diskette, a hard disk, a RAM, a ROM, an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0128] To provide for interaction with a user, the systems and techniques described here can be implemented on an electronic device having a display device (e.g., a Cathode-Ray Tube (CRT) or a Liquid Crystal Display (LCD) monitor) for displaying information to the user and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the electronic device. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form, including acoustic, speech, or tactile input.

[0129] The systems and techniques described here can be implemented in a computing system that includes a back end component (e.g., as a data server), or that includes a middleware component (e.g., an application server), or that includes a front end component (e.g., a user computer having a graphical user interface or a Web browser through which a user can interact with an implementation of the systems and techniques described here), or any combination of such back end, middleware, or front end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a Local Area Network (LAN), a Wide Area Network (WAN), a blockchain network, and the Internet.

[0130] The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system, to solve the defects of large management difficulty and weak business scalability in traditional physical host and virtual private server (VPS) services.

[0131] The various forms of flow shown above can be reordered, additional steps added, or steps deleted. For example, the various steps described in this application can be performed in parallel, in series, or in a different order, as long as the desired results of the technical solutions of the present application are achieved, which are not limited herein.

Claims

1. An axial length measurement method, comprising: acquiring at least one optical coherence tomography (OCT) image of ocular tissue in a range from cornea to retina of an eye to be measured; performing position recognition on the at least one OCT image to obtain a plurality of target positions, wherein the plurality of target positions comprises a corneal epithelium vertex position and a retinal macular fovea position; and determining an axial length of the eye to be measured based on the plurality of target positions. The performing of the position recognition on the at least one OCT image to obtain the plurality of target positions comprises:

2. The method of claim 1, wherein, performing optical axis recognition on the at least one OCT image to obtain at least one target OCT image containing an optical axis in the at least one OCT image; and performing position recognition on the at least one target OCT image to obtain the plurality of target positions.

3. The method of claim 2, further comprising: in response to a number of the at least one target OCT image being less than a preset value, prompting a user to re-shoot a set of OCT images for the eye to be measured for axial length measurement. The performing of the position recognition on the at least one OCT image to obtain the plurality of target positions comprises:

4. The method of claim 2, wherein, for each OCT image in the at least one target OCT image, performing ocular tissue recognition based on the OCT image to determine a corneal epithelium boundary and a retinal pigment epithelium boundary; performing optical axis recognition based on the OCT image and determining a first intersection point of an optical axis with the corneal epithelium boundary and a second intersection point of the optical axis with the retinal pigment epithelium boundary; and wherein the first intersection point corresponds to the corneal epithelium vertex position and the second intersection point corresponds to the retinal macular fovea position. The determining of the axial length of the eye to be measured based on the plurality of target positions comprises:

5. The method of claim 1, wherein, determining the axial length of the eye to be measured based on the corneal epithelium vertex position and the retinal macular fovea position. The determining of the axial length of the eye to be measured based on the corneal epithelium vertex position and the retinal macular fovea position comprises:

6. The method of claim 5, wherein, calculating an initial distance between the corneal epithelium vertex position and the retinal macular fovea position; and obtaining an equivalent axial length of the eye to be measured based on the initial distance, an axial resolution of the image, and an equivalent refractive index of ocular tissue.

7. The method of claim 1, wherein the plurality of target positions further comprises a corneal endothelium intersection position, a lens anterior surface intersection position, and a lens posterior surface intersection position; wherein the determining of the axial length of the eye to be measured based on the plurality of target positions comprises: determining the axial length of the eye to be measured based on the corneal epithelium vertex position, the corneal endothelium intersection position, the lens anterior surface intersection position, the lens posterior surface intersection position, and the retinal macular fovea position. The determining of the axial length of the eye to be measured based on the corneal epithelium vertex position, the corneal endothelium intersection position, the lens anterior surface intersection position, the lens posterior surface intersection position, and the retinal macular fovea position comprises:

8. The method of claim 7, wherein, ​ calculating a first distance between the corneal epithelium apex position and the corneal endothelium intersection position, and obtaining a length of a first ocular axial substructure based on the first distance, an image axial resolution, and a corneal refractive index; calculating a second distance between the corneal endothelium intersection position and the lens anterior surface intersection position, and obtaining a length of a second ocular axial substructure based on the second distance, the image axial resolution, and an anterior chamber refractive index; calculating a third distance between the lens anterior surface intersection position and the lens posterior surface intersection position, and obtaining a length of a third ocular axial substructure based on the third distance, the image axial resolution, and a lens refractive index; calculating a fourth distance between the lens posterior surface intersection position and the retinal macular fovea position, and obtaining a length of a fourth ocular axial substructure based on the fourth distance, the image axial resolution, and a vitreous refractive index; and determining an ocular axial length of the eye to be measured based on the length of the first ocular axial substructure, the length of the second ocular axial substructure, the length of the third ocular axial substructure, and the length of the fourth ocular axial substructure.

9. The method of claim 1, further comprising: displaying at least one of a transverse OCT image and a longitudinal OCT image in the at least one OCT image; cropping a preset image region containing a retinal macular fovea from the displayed OCT image; and displaying the cropped preset image region in a target region in the displayed OCT image. The cropping of the preset image region containing the retinal macular fovea from the displayed OCT image comprises:

10. The method of claim 9, wherein, cropping a middle image region from the displayed OCT image to obtain a retinal OCT image; identifying a brightness of the retinal OCT image to determine a position of maximum brightness; cropping a target image region from the retinal OCT image based on the position of maximum brightness and a preset display range; and using the cropped target image region as the preset image region containing the retinal macular fovea.

11. The method of claim 1, further comprising: acquiring and displaying a pupil map of the eye to be measured; determining an imaging direction of each OCT image in the at least one OCT image; and displaying the imaging direction of each OCT image in the displayed pupil map.

12. The method of claim 11, further comprising: for each imaging direction, in response to the imaging direction being triggered, specially displaying the imaging direction and displaying an OCT image corresponding to the imaging direction in linkage.

13. The method of claim 11, further comprising: specially displaying a transverse imaging direction and a longitudinal imaging direction; displaying all or part of an OCT image corresponding to the transverse imaging direction in linkage; and displaying all or part of an OCT image corresponding to the longitudinal imaging direction in linkage.

14. An ocular axial length measuring device, comprising: ​ ​ ​ an optical coherence tomography (OCT) image acquisition module configured to acquire at least one OCT image of eye tissue in a range from a cornea to a retina of an eye to be measured; a target position identification module configured to identify positions of the at least one OCT image to obtain a plurality of target positions, wherein the plurality of target positions include a corneal epithelial apex position and a retinal macular fovea position; and an axial length determination module configured to determine an axial length of the eye to be measured based on the plurality of target positions. 15.An electronic device, comprising: at least one processor; and a memory connected to the at least one processor in communication; wherein the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to perform the axial length measurement method of any one of claims 1-13. 16.A computer readable storage medium storing computer instructions for causing a processor to implement the axial length measurement method of any one of claims 1-13 when executed. ​

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