Optical system for measuring axial length of an eye and method thereof

Abstract

The application discloses an optical system and a method thereof for measuring an axial length, which comprises an OCT light source module, an OCT imaging module, an eye posterior segment OCT sample arm module and an anterior segment slit imaging assembly. The OCT light source module provides measuring light, which is incident on the fundus of an eye to be measured after passing through the eye posterior segment OCT sample arm module, and the OCT imaging module receives the measuring light to obtain an eye posterior segment OCT image. The anterior segment slit imaging assembly comprises an anterior segment slit light source module, an anterior segment slit imaging module and an anterior segment slit imaging adjustment light path module. The anterior segment slit light source module provides slit light, which is focused on the anterior segment of the eye to be measured after passing through the anterior segment slit imaging adjustment light path module, and the anterior segment slit imaging module receives the slit light to obtain an anterior segment slit image. The first optical path data and the second optical path data are obtained by using the eye posterior segment OCT image and the anterior segment slit image respectively, so that the axial length is calculated. The application avoids the influence of the movement of the eye to be measured, and improves the axial length measurement precision.

Description

[0001] This application claims priority to the Chinese patent application No. 202311547355.8, filed on November 20, 2023, entitled "An optical system for measuring axial length of eye and method thereof", the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of medical devices, and in particular to an optical system for measuring axial length of eye and method thereof. BACKGROUND

[0003] Nowadays, there are more and more elderly people suffering from cataract eye diseases, and implanting artificial lenses is an effective solution for treating cataracts. However, the calculation of artificial lenses requires many parameters, such as corneal anterior and posterior surface curvature, corneal thickness, anterior chamber depth, lens thickness, lens anterior and posterior surface curvature, axial length of eye, white to white distance, pupil diameter, etc. There are many parameters to be measured, but often multiple medical devices are needed to detect the complete data. Therefore, if a device can obtain the above data, it will not only improve the convenience of measurement, but also improve the accuracy of measurement. In addition, with the increasing number of myopic teenagers, the situation of myopia prevention and control is becoming more and more severe, and the measurement of axial length of eye is an important reference index for myopia prevention and control. Therefore, how to simply and cheaply realize the measurement of many ophthalmic indicators is the development trend of ophthalmic medical devices.

[0004] Optical coherence tomography (OCT) is a new optical imaging technology. Compared with traditional clinical imaging methods, it has the advantages of high resolution, fast imaging speed, no radiation damage, moderate price, compact structure, etc., and is an important potential tool for basic medical research and clinical diagnosis. Currently, in a variety of ophthalmic devices using optical instruments, OCT devices for ophthalmic examination and treatment have become an indispensable ophthalmic device for the diagnosis of ophthalmic diseases.

[0005] In patent document 201911073986.4, the influence of eye movement in the axial length measurement process is corrected by imaging the lateral cornea, but the lateral cornea imaging is easily affected by environmental light, and the cornea is relatively transparent, so it is difficult to identify the corneal vertex, and the error is large. In patent document 201410135999.0 and patent document 202011120798.5, the anterior and posterior segment OCT switching technology is used to realize corneal and posterior segment OCT imaging, thereby measuring the axial length of the eye, but the anterior and posterior segment OCT switching process requires more time, which may affect the eye movement, resulting in a decrease in the reliability of measuring the axial length of the eye.

[0006] The disclosure of the foregoing Background Art is provided merely as aid to understanding the concepts and technical solutions of the present application, and it does not necessarily constitute the prior art of the present patent application. If there is no explicit evidence that the foregoing Background Art has been disclosed before the filing date of the present patent application, the foregoing Background Art should not be used to evaluate the novelty and inventiveness of the present application. SUMMARY

[0007] To solve the above technical problems, the present application provides an optical system for measuring axial length of eye and a method thereof, which avoids the influence of the movement of the eye to be measured and improves the measurement accuracy of the axial length of the eye.

[0008] To achieve the above-mentioned purposes, the present application adopts the following technical solutions:

[0009] In a first aspect, the present application discloses an optical system for measuring axial length of eye, comprising an OCT light source module, an OCT imaging module, an ocular posterior segment OCT sample arm module, and an anterior segment slit imaging assembly, wherein:

[0010] The OCT light source module is configured to provide measurement light, which is incident on the fundus of the eye to be measured after passing through the ocular posterior segment OCT sample arm module, and the OCT imaging module is configured to receive the measurement light returned from the fundus of the eye to be measured to obtain an ocular posterior segment OCT image.

[0011] The anterior segment slit imaging assembly comprises an anterior segment slit light source module, an anterior segment slit imaging module, and an anterior segment slit imaging adjustment optical path module, the anterior segment slit light source module is configured to provide slit light, the slit light is focused on the anterior segment of the eye to be measured after passing through the anterior segment slit imaging adjustment optical path module, and the anterior segment slit imaging module is configured to receive the returned slit light to obtain an anterior segment slit image.

[0012] The first optical path data and the second optical path data are obtained respectively by using the ocular posterior segment OCT image and the anterior segment slit image, and the axial length of the eye is calculated by using the first optical path data and the second optical path data.

[0013] Preferably, the anterior segment slit imaging module comprises an anterior segment slit imaging lens 1801 and an anterior segment slit imaging device 1803, the slit light emitted by the anterior segment slit light source module is focused on the anterior segment of the eye to be measured, and the returned anterior segment slit light signal passes through the anterior segment slit imaging lens 1801 and is received by the anterior segment slit imaging device 1803, the anterior segment slit imaging device 1803 obtains the anterior segment slit image according to the anterior segment slit light signal.

[0014] Preferably, the anterior segment slit imaging adjustment optical path module comprises an objective lens 1305, which is located on the optical path of the first direction, wherein the optical path of the first direction is perpendicular to the human eye to be measured, and the anterior segment slit imaging lens 1801 and the anterior segment slit imaging device 1803 are arranged below the objective lens 1305, respectively.

[0015] Preferably, the anterior segment slit light source module comprises an anterior segment slit light source 1809 and a pre-splitting mirror 1303, and the slit light emitted by the anterior segment slit light source 1809 passes through the pre-splitting mirror 1303 and then passes through the anterior segment slit imaging adjustment optical path module to focus on the anterior segment of the human eye to be measured.

[0016] Preferably, the posterior segment OCT sample arm module comprises an optical path scanning device 1109 and an posterior segment OCT imaging adjustment optical path unit, and the posterior segment OCT imaging adjustment optical path unit and the anterior segment OCT insertion mirror 1501 form an anterior segment OCT imaging adjustment optical path unit, the anterior segment slit imaging adjustment optical path module adopts the anterior segment OCT imaging adjustment optical path unit, and the anterior segment slit light source module adopts the OCT light source module and the optical path scanning device 1109 to generate slit light, wherein the measurement light provided by the OCT light source module passes through one-dimensional scanning of the optical path scanning device 1109 to emit slit light and then passes through the anterior segment OCT imaging adjustment optical path unit to focus on the anterior segment of the human eye to be measured.

[0017] Preferably, the posterior segment OCT sample arm module comprises an optical path scanning device 1109 and an posterior segment OCT imaging adjustment optical path unit, and the posterior segment OCT imaging adjustment optical path unit and the anterior segment OCT insertion mirror 1501 form an anterior segment OCT imaging adjustment optical path unit, the anterior segment slit imaging adjustment optical path module adopts the anterior segment OCT imaging adjustment optical path unit, and the anterior segment slit light source module adopts an anterior segment slit light source 3809, a wavelength division multiplexer 3807, an optical fiber 1106 and the optical path scanning device 1109 to generate slit light, wherein the light output by the anterior segment slit light source 3809 is coupled by the wavelength division multiplexer 3807 and then transmitted into the optical fiber 1106, and the light beam output from the optical fiber 1106 passes through one-dimensional scanning of the optical path scanning device 1109 to emit slit light and then passes through the anterior segment OCT imaging adjustment optical path unit to focus on the anterior segment of the human eye to be measured.

[0018] Preferably, the posterior ocular OCT sample arm module comprises an optical path scanning device 1109 and a posterior ocular OCT imaging adjustment optical path unit, the anterior ocular OCT insertion lens 1501 and the anterior ocular OCT imaging adjustment optical path unit form an anterior ocular OCT imaging adjustment optical path unit, the anterior ocular slit imaging adjustment optical path module adopts the anterior ocular OCT imaging adjustment optical path unit, the anterior ocular slit light source module adopts the anterior ocular slit light source 4809, the parallel optical fiber 2106 and the optical path scanning device 1109 to generate slit light, the light output by the anterior ocular slit light source 4809 passes through the parallel optical fiber 2106, and the light beam output by the parallel optical fiber 2106 is focused on the anterior ocular segment of the human eye to be measured after one-dimensional scanning of the optical path scanning device 1109 and passing through the anterior ocular slit imaging adjustment optical path module.

[0019] Preferably, the posterior ocular OCT sample arm module comprises an optical path scanning device 1109 and a posterior ocular OCT imaging adjustment optical path unit, the anterior ocular slit imaging adjustment optical path module adopts the posterior ocular OCT imaging adjustment optical path unit, the anterior ocular slit light source module comprises an anterior ocular slit light source 5809, a lens 5807 and a beam splitter 5805, the anterior ocular slit light source 5809 outputs light, the light passes through the lens 5807, is reflected by the beam splitter 5805, is one-dimensionally scanned by the optical path scanning device 1109 to form slit light, and is focused on the anterior ocular segment of the human eye to be measured after passing through the anterior ocular slit imaging adjustment optical path module.

[0020] Preferably, the posterior ocular OCT imaging adjustment optical path unit comprises a posterior ocular OCT field lens 1301, a front beam splitter 1303 and an objective lens 1305; the measurement light provided by the OCT light source module passes through the posterior ocular OCT field lens 1301 after being reflected by the optical path scanning device 1109, is reflected by the front beam splitter 1303 to the objective lens 1305, is focused on the fundus of the human eye to be measured after passing through the human eye to be measured, and returns a posterior ocular light signal to the OCT imaging module, and the OCT imaging module acquires a posterior ocular OCT image according to the posterior ocular light signal;

[0021] The anterior ocular OCT imaging adjustment optical path unit is formed by inserting the anterior ocular OCT insertion lens 1501 into the optical path formed by the posterior ocular OCT imaging adjustment optical path unit, the slit light passes through the posterior ocular OCT field lens 1301 and the anterior ocular OCT insertion lens 1501 in sequence, is reflected by the front beam splitter 1303 to the objective lens 1305, is focused on the anterior ocular segment of the human eye to be measured, and returns an anterior ocular slit light signal to the anterior ocular slit imaging module, and the anterior ocular slit imaging module acquires an anterior ocular slit image according to the anterior ocular slit light signal.

[0022] Preferably, the first optical path data refers to an optical path hRetinal of an apex of an ocular posterior segment OCT image to a retinal signal in the ocular posterior segment OCT image measured according to the ocular posterior segment OCT image of the human eye to be measured, and the second optical path data refers to an optical path hCornea of an apex of an ocular anterior segment slit image to a corneal apex of the human eye to be measured measured according to the ocular anterior segment slit image of the human eye to be measured.

[0023] The axial length is calculated by using the first optical path data and the second optical path data, including: calculating the axial length Leye of the human eye to be measured according to the optical path change X of the ocular posterior segment OCT sample arm module and the measured optical path hRetinal and optical path hCornea when the ocular posterior segment OCT image of the human eye to be measured is acquired.

[0024] In a second aspect, the present application discloses a method for measuring an axial length, characterized by using the optical system of the first aspect to measure the axial length of the human eye to be measured, including the following steps:

[0025] Acquiring an ocular posterior segment OCT image of the human eye to be measured to measure an optical path hRetinal of an apex of the ocular posterior segment OCT image to a retinal signal in the ocular posterior segment OCT image according to the ocular posterior segment OCT image of the human eye to be measured;

[0026] Acquiring an ocular anterior segment slit image of the human eye to be measured to measure an optical path hCornea of an apex of the ocular anterior segment slit image to a corneal apex of the human eye to be measured according to the ocular anterior segment slit image of the human eye to be measured;

[0027] Calculating the axial length Leye of the human eye to be measured according to the optical path change X of the ocular posterior segment OCT sample arm module and the measured optical path hRetinal and optical path hCornea when the ocular posterior segment OCT image of the human eye to be measured is acquired.

[0028] Preferably, the axial length Leye of the human eye to be measured is calculated by using the following formula:

[0029] Leye = △L + X - hCornea + hRetinal;

[0030] Wherein, △L represents a spatial distance between the apex of the ocular posterior segment OCT image and the apex of the ocular anterior segment slit image, and X represents an optical path change of the ocular posterior segment OCT sample arm module when the ocular posterior segment OCT image of the human eye to be measured is acquired.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows: The optical system and method for measuring axial length proposed in the present invention further measure the axial length by acquiring posterior segment OCT images and anterior segment slit images respectively. The anterior segment slit imaging achieves accurate positioning of the cornea. Combined with posterior segment OCT image acquisition, the switching time can be reduced or even eliminated, thereby avoiding the influence of the subject's eye movement and improving the accuracy of axial length measurement.

[0032] In a further scheme, by adding a separate anterior segment slit light source to generate slit light, and by using different imaging schemes to acquire posterior segment OCT images and anterior segment slit images, both can be acquired simultaneously, thereby minimizing the influence of eye movement on the subject and further improving the measurement accuracy of axial length.

[0033] In a further solution, an OCT light source module or a separate anterior segment slit light source is combined with an optical path scanning device to generate slit light. This is then combined with an anterior segment OCT imaging adjustment optical path unit, allowing the slit light to be focused onto the cornea of ​​the subject, thereby acquiring an anterior segment slit image. This solution eliminates the need for additional optical path debugging, reducing system debugging difficulty and increasing system debugging speed. Moreover, only the anterior segment OCT insertion lens needs to be adjusted between acquiring posterior segment OCT images and anterior segment slit images, without adjusting the optical path. The switching time is shorter, faster than existing technologies, and more easily avoids the influence of eye movements during long-term axial length measurements. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the ophthalmic optical biometry system according to Embodiment 1 of the present invention;

[0035] Figure 2 yes Figure 1 Optical path diagram of the posterior segment OCT imaging system of the China Ophthalmic Optical Biometry System;

[0036] Figure 3 yes Figure 1 Optical path diagram of the anterior segment OCT imaging system of the Optical Biometry System of the Chinese Academy of Ophthalmic Sciences;

[0037] Figure 4a yes Figure 1 Front view of the anterior segment camera module of the optical biometry system at the Chinese Academy of Ophthalmic Sciences;

[0038] Figure 4b yes Figure 1 Top view of the anterior segment camera module of the Chinese Ophthalmic Optical Biometry System;

[0039] Figure 5 yes Figure 1 Optical path diagram of anterior segment slit imaging using the optical biometry system of the Chinese Academy of Ophthalmic Sciences;

[0040] Figure 6 is Figure 1 Schematic diagram of fixation optical module of ophthalmic optical biometric system;

[0041] Figure 7 is

[0042] Figure 8 is

[0043] Figure 9 is Figure 8 Optical path diagram of anterior segment slit imaging of ophthalmic optical biometric system;

[0044] Figure 10 is Figure 8 Schematic diagram of fixation optical module of ophthalmic optical biometric system;

[0045] Figure 11 is

[0046] Figure 12 is Figure 11 Structural schematic diagram of optical fiber of ophthalmic optical biometric system;

[0047] Figure 13 is Figure 11 Optical path diagram of posterior segment OCT imaging system of ophthalmic optical biometric system;

[0048] Figure 14 is Figure 11 Optical path diagram of anterior segment OCT imaging system of ophthalmic optical biometric system;

[0049] Figure 15 is Figure 11 Optical path diagram of anterior segment slit imaging of ophthalmic optical biometric system;

[0050] Figure 16 is

[0051] Figure 17 is Figure 16 Structural schematic diagram of parallel optical fiber of ophthalmic optical biometric system;

[0052] Figure 18 is

[0053] Figure 19 is Figure 16 Optical path diagram of anterior segment slit imaging of ophthalmic optical biometric system;

[0054] Figure 20 is a structural schematic diagram of an ophthalmic optical biometric system according to an embodiment of the present application;

[0055] Figure 21 is Figure 20 is a light path diagram of an anterior chamber slit imaging of the ophthalmic optical biometric system.

[0056] BRIEF DESCRIPTION OF DRAWINGS 10, probe module; 1101, OCT light source; 1103, fiber coupler; 1105, polarization controller; 1106, optical fiber; 11061, core; 11063, cladding; 11065, sheath; 1107, fiber collimator; 1109, light path scanning device; 11091, X direction scanning device; 11093, Y direction scanning device; 1120, reference arm module; 1141, detector; 1143, computer; 1301, posterior segment OCT field lens; 1303, pre-splitting prism; 1305, objective lens; 1501, anterior chamber OCT insertion lens; 1701, fixation light source; 1703, fixation light path lens; 18, combination module; 1801, anterior chamber slit imaging lens; 1803, anterior chamber slit imaging device; 1807, gonioscopic splitting prism; 1809, anterior chamber slit light source; 1901, illumination light source; 1903, iris relay lens; 1905, iris splitting prism; 1907, anterior segment camera lens; 1909, anterior segment camera device; E, human eye to be measured; Er, fundus; L1, optical axis; 2106, parallel optical fiber; 21061, OCT light path core; 21062, anterior chamber slit illumination light path core; 21063, OCT light path cladding; 21065, sheath; 3106, double core optical fiber; 31061, core; 31062, core; 31063, optical fiber cladding; 31064, optical fiber cladding; 31065, sheath; 31066, sheath; 31069, large sheath; 3807, wavelength division multiplexer; 3809, anterior chamber slit light source; 4809, anterior chamber slit light source; 5805, splitting prism; 5807, lens; 5809, anterior chamber slit light source. DETAILED DESCRIPTION

[0057] The present application will be further described with reference to the drawings, wherein like numerals refer to like parts throughout the several views, and wherein the implementation will be described in sections as follows. It should be noted that the following description is only exemplary and is not intended to limit the scope or application of the application.

[0058] The present application will be described in detail below with reference to the accompanying drawings and specific embodiments, so as to better understand the present application, but the following embodiments do not limit the scope of the present application. In addition, it should be noted that the drawings provided in the following embodiments only schematically illustrate the basic concept of the present application, and the components related to the present application are shown in the drawings, but not drawn according to the number, shape and size of the components in actual implementation. The shape, number and proportion of each component in actual implementation can be arbitrarily changed, and the component layout form can be more complex.

[0059] It should be understood that the terms "upper", "lower", "front", "back", "inner", "outer", "left", "right" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0060] The ophthalmic optical biometric system provided by the present application is mainly used for measuring the optical parameters related to the patient's eye and checking the patient's eye, and can measure the anterior segment OCT image of the human eye, the posterior segment OCT image of the eye, the anterior segment camera of the eye, the axial length of the human eye, the anterior chamber depth, the white-to-white distance and many other ophthalmic parameters. Among them, the measurement of the axial length of the human eye and other related ophthalmic parameters is mainly based on optical coherence tomography technology, combined with anterior and posterior segment OCT acquisition technology, anterior segment slit imaging, anterior segment camera technology. Through iris recognition technology, anterior segment OCT image automatic recognition technology, posterior segment OCT image automatic recognition technology and other technologies, the system realizes full automatic detection. The axial length measurement technology is realized by combining the anterior segment slit imaging to realize the accurate positioning of the cornea (i.e. anterior segment) position, and the posterior segment OCT acquisition technology.

[0061] The present application adopts the anterior and posterior segment fast switching OCT system, combined with the anterior segment camera and automatic recognition technology, which can solve the detection of many optical parameters of the human eye; thereby meeting the needs of different parts measurement, and can obtain accurate data of many important parameters of the human eye, meeting the needs of clinical diagnosis of doctors. Through iris recognition technology, anterior segment OCT image automatic recognition technology, posterior segment OCT image automatic recognition technology and other technologies, the system realizes full automatic detection.

[0062] The first preferred embodiment of the present application discloses an optical system for measuring axial length, comprising an OCT light source module, an OCT imaging module, an ocular posterior segment OCT sample arm module, and an anterior segment slit imaging assembly, wherein: the OCT light source module is configured to provide measurement light, the measurement light is incident on the fundus of a human eye to be measured after passing through the ocular posterior segment OCT sample arm module, the OCT imaging module receives the measurement light returned from the fundus of the human eye to be measured to obtain an ocular posterior segment OCT image; the anterior segment slit imaging assembly comprises an anterior segment slit light source module, an anterior segment slit imaging module, and an anterior segment slit imaging light path adjustment module, the anterior segment slit light source module is configured to provide slit light, the slit light is focused on the anterior segment of the human eye to be measured after passing through the anterior segment slit imaging light path adjustment module, and the anterior segment slit imaging module receives the returned slit light to obtain an anterior segment slit image; first optical path data and second optical path data are obtained by using the ocular posterior segment OCT image and the anterior segment slit image, respectively, and the axial length is calculated by using the first optical path data and the second optical path data.

[0063] The first optical path data refers to the optical path hRetinal from the top of the ocular posterior segment OCT image to the retinal signal in the ocular posterior segment OCT image measured according to the ocular posterior segment OCT image of the human eye to be measured, and the second optical path data refers to the optical path hCornea from the top of the anterior segment slit image to the vertex of the cornea of the human eye to be measured measured according to the anterior segment slit image of the human eye to be measured; the axial length is calculated by using the first optical path data and the second optical path data, comprising: the axial length Leye of the human eye to be measured is calculated according to the optical path change X of the ocular posterior segment OCT sample arm module, the measured optical path hRetinal, and the optical path hCornea when the ocular posterior segment OCT image of the human eye to be measured is obtained.

[0064] The anterior segment slit imaging module comprises an anterior segment slit imaging lens 1801 and an anterior segment slit imaging device 1803, the slit light emitted by the anterior segment slit light source module is focused on the anterior segment of the human eye to be measured, the returned anterior segment slit light signal passes through the anterior segment slit imaging lens 1801 and is received by the anterior segment slit imaging device 1803, and the anterior segment slit imaging device 1803 obtains the anterior segment slit image according to the anterior segment slit light signal. Further, the anterior segment slit imaging light path adjustment module comprises an ocular objective lens 1305, the ocular objective lens 1305 is located on the light path in the first direction, the light path in the first direction is perpendicular to the human eye to be measured, and the anterior segment slit imaging lens 1801 and the anterior segment slit imaging device 1803 are arranged below the ocular objective lens 1305. The anterior segment slit imaging module in the following embodiments one to four adopts the structure.

[0065] In some preferred embodiments, such as the following embodiment one, the anterior segment slit light source module comprises the anterior segment slit light source 1809 and the front beam splitter 1303, the slit light emitted by the anterior segment slit light source 1809 passes through the front beam splitter 1303, then passes through the anterior segment slit imaging adjustment optical path module, and is focused on the anterior segment of the human eye to be measured. Specifically, the slit light emitted by the anterior segment slit light source 1809 is reflected by the gonioprism 1807, then reflected by the ophthalmic prism 1905, transmitted through the ophthalmic relay lens 1903 and the front beam splitter 1303, and focused on the anterior segment of the human eye to be measured through the objective lens 1305.

[0066] In some preferred embodiments, such as the following embodiment two, the posterior segment OCT sample arm module comprises the optical path scanning device 1109 and the posterior segment OCT imaging adjustment optical path unit, the posterior segment OCT imaging adjustment optical path unit and the anterior segment OCT insert lens 1501 form the anterior segment OCT imaging adjustment optical path unit, the anterior segment slit imaging adjustment optical path module adopts the anterior segment OCT imaging adjustment optical path unit, and the anterior segment slit light source module adopts the OCT light source module and the optical path scanning device 1109 to generate slit light, wherein the measurement light provided by the OCT light source module passes through one-dimensional scanning of the optical path scanning device 1109, emits slit light, and passes through the anterior segment OCT imaging adjustment optical path unit and is focused on the anterior segment of the human eye to be measured.

[0067] In some preferred embodiments, such as the following embodiment three, the posterior segment OCT sample arm module comprises the optical path scanning device 1109 and the posterior segment OCT imaging adjustment optical path unit, the posterior segment OCT imaging adjustment optical path unit and the anterior segment OCT insert lens 1501 form the anterior segment OCT imaging adjustment optical path unit, the anterior segment slit imaging adjustment optical path module adopts the anterior segment OCT imaging adjustment optical path unit, and the anterior segment slit light source module adopts the anterior segment slit light source 3809, the wavelength division multiplexer 3807, the optical fiber 1106 and the optical path scanning device 1109 to generate slit light, the light output by the anterior segment slit light source 3809 is coupled after passing through the wavelength division multiplexer 3807, transmitted into the optical fiber 1106, the light beam output in the optical fiber 1106 is one-dimensionally scanned by the optical path scanning device 1109, emits slit light, and passes through the anterior segment OCT imaging adjustment optical path unit and is focused on the anterior segment of the human eye to be measured.

[0068] In some preferred embodiments, such as the following embodiment four, the posterior ocular segment OCT sample arm module comprises the optical path scanning device 1109 and the posterior ocular segment OCT imaging adjustment optical path unit, the posterior ocular segment OCT imaging adjustment optical path unit and the anterior ocular segment OCT insert mirror 1501 form the anterior ocular segment OCT imaging adjustment optical path unit, the anterior ocular segment slit imaging adjustment optical path module uses the anterior ocular segment OCT imaging adjustment optical path unit, the anterior ocular segment slit light source module uses the anterior ocular segment slit light source 4809, the parallel optical fiber 2106 and the optical path scanning device 1109 to generate slit light, the light output by the anterior ocular segment slit light source 4809 passes through the parallel optical fiber 2106, the light beam output by the parallel optical fiber 2106 is emitted as slit light after one-dimensional scanning by the optical path scanning device 1109 and focuses on the anterior ocular segment of the human eye to be measured after passing through the anterior ocular segment OCT imaging adjustment optical path unit.

[0069] Further, in embodiments two, three and four, the posterior ocular segment OCT imaging adjustment optical path unit comprises the posterior ocular segment OCT field lens 1301, the front dichroic mirror 1303 and the objective lens 1305; the measurement light provided by the OCT light source module is reflected by the optical path scanning device 1109, passes through the posterior ocular segment OCT field lens 1301, is reflected by the front dichroic mirror 1303 to the objective lens 1305, converges on the fundus of the human eye to be measured to return the posterior ocular segment optical signal to the OCT imaging module, and the OCT imaging module acquires the posterior ocular segment OCT image according to the posterior ocular segment optical signal; the anterior ocular segment OCT imaging adjustment optical path unit is formed by inserting the anterior ocular segment OCT insert mirror 1501 into the optical path formed by the posterior ocular segment OCT imaging adjustment optical path unit, the slit light passes through the posterior ocular segment OCT field lens 1301 and the anterior ocular segment OCT insert mirror 1501 in turn, is reflected by the front dichroic mirror 1303 to the objective lens 1305, converges on the anterior ocular segment of the human eye to be measured to return the anterior ocular segment slit optical signal to the anterior ocular segment slit imaging module, and the anterior ocular segment slit imaging module acquires the anterior ocular segment slit image according to the anterior ocular segment slit optical signal.

[0070] The ophthalmic optical biometric system proposed by the present application is further described in detail in combination with a plurality of specific embodiments.

[0071] Embodiment one

[0072] The embodiment one of the present application discloses an ophthalmic optical biometric system, which comprises an OCT imaging module, a posterior ocular segment OCT sample arm module, an anterior ocular segment OCT insert mirror, a fixation optical module, an anterior ocular segment camera module and an anterior ocular segment slit imaging module. Each module can perform corresponding functions, some optical components are shared between the modules, and each module is combined appropriately to form the ophthalmic optical biometric system.

[0073] The entry and exit of the anterior segment OCT insertion mirror 1501 is controlled by the computer 1143, and the light path switching and OCT imaging of different parts of the human eye are realized by the translation of the fiber collimator 1107 along the optical axis.

[0074] As Figure 1 shown is a structural diagram of the ophthalmic optical biometric system of the embodiment one of the present application, wherein the probe module 10 comprises: a posterior segment OCT sample arm module, an anterior segment OCT insertion mirror, a fixation optical module, an anterior segment camera module, and an anterior segment slit imaging module. The probe module 10 as a whole is driven by three motors (not shown in the figure) and can realize X / Y / Z three-dimensional translation. In the embodiment, the X axis is defined as the axis perpendicular to the paper surface, the Y axis is defined as the axis in the up-down direction parallel to the paper surface, and the Z axis is defined as the axis in the left-right direction parallel to the paper surface, that is, the X axis and the Y axis directions are respectively the horizontal axis and the vertical axis in the plane parallel to the outer surface of the human eye E to be measured, and the Z axis direction is the direction perpendicular to the plane parallel to the outer surface of the human eye E to be measured. The above definitions are only for the convenience of explanation and are not limited thereto.

[0075] (1) OCT imaging system

[0076] The OCT imaging module comprises an OCT light source 1101, a fiber coupler 1103, a reference arm module 1120, a detector 1141, a computer 1143, a polarization controller 1105, and a sample arm module. The OCT light source 1101 outputs near-infrared light with a wavelength of about 800 nm. The sample arm module comprises a posterior segment OCT sample arm module and an anterior segment insertion mirror 1501. The computer 1143 in the present application is not a traditional PC computer, but a circuit control and processing system capable of performing functions such as operation, control, storage, and display.

[0077] The light path of the OCT imaging module comprises an OCT light source 1101 (which can adopt a weak coherent light source). The light output by the OCT light source 1101 is provided to the sample arm module and the reference arm module 1120 through the fiber coupler 1103. The reference arm module 1120 has a known length. The light provided by the fiber coupler 1103 to the reference arm module 1120 can be transmitted to the fiber coupler 1103 again. The sample arm module provides light to the human eye E to be measured. The light scattered back from the human eye E to be measured passes through the light transmitted from the sample arm module, the polarization controller 1105, and the reference arm module 1120, and the light transmitted from the sample arm module and the reference arm module 1120 interferes with each other in the fiber coupler 1103. The interference light is detected by the detector 1141, processed by the computer 1143, and finally the OCT image of the human eye E to be measured is displayed. The light path scanning device 1109 adopts a two-dimensional scanning mechanism, which is composed of an X-direction scanning device 11091 and a Y-direction scanning device 11093. The sample (human eye to be measured) is scanned by the light path scanning device 1109, and the tomographic imaging of the OCT is realized.

[0078] (2) Posterior segment OCT imaging system

[0079] like Figure 2 The diagram shows the optical path of the posterior segment OCT imaging system. The posterior segment OCT sample arm module includes an optical path scanning device 1109 and a posterior segment OCT imaging adjustment optical path unit. The posterior segment OCT imaging adjustment optical path unit includes a fiber optic collimator 1107, a posterior segment OCT field lens 1301, a front beam splitter 1303, and an eyepiece objective 1305. The optical path scanning device 1109 can be a one-dimensional optical path switching scanning device, or it can be two-dimensional or even three-dimensional; the optical path scanning device 1109 realizes one-dimensional to multi-dimensional scanning of the human eye E under test. The optical fiber exits through the sample arm fiber optic head (not shown in the figure), which is adjacent to the fiber optic collimator 1107; the sample arm fiber optic head and the fiber optic collimator 1107 are driven by a motor and can translate along the principal optical axis of the fiber optic collimator 1107, thereby changing the optical path of the sample arm optical path. Similarly, the matching of optical path lengths between the sample arm and the reference arm can also be achieved by changing the optical path length of the reference arm; where the optical fiber is connected to the optical fiber head of the sample arm.

[0080] During posterior segment OCT imaging, light emitted from the fiber optic collimator 1107 is reflected by the optical path scanning device 1109. The optical path scanning device 1109 is controlled by the computer 1143. After reflection by the optical path scanning device 1109, the light beam passes through the posterior segment OCT field lens 1301, is reflected by the front beam splitter 1303 to the eyepiece objective lens 1305, and finally converges to the fundus Er of the subject eye E. The detection beam of the posterior segment OCT imaging optical path system satisfies the condition that the center line of the scanning beam converges near the pupil of the subject eye, while at any given time, the OCT beam is focused on the fundus Er of the subject eye.

[0081] For different human eyes (with varying refractive powers), by adjusting the eyepiece objective 1305, the OCT beam can be focused onto the retina (Er). This effectively improves the signal-to-noise ratio and lateral resolution of the OCT image during retinal measurements.

[0082] The front beam splitter 1303 can reflect the signal light emitted by the OCT light source 1101 and transmit the fixed light emitted by the fixed light source 1701 in the fixed optical module; transmit the light emitted by the anterior segment slit light source 1809 in the anterior segment slit imaging module; and also transmit the illumination light emitted by the illumination light source 1901 in the anterior segment camera module.

[0083] At this time, the anterior segment OCT insertion lens 1501 is controlled by the computer 1143 to switch out the posterior segment OCT imaging optical path.

[0084] When measuring the fundus, scanning is performed using the X-axis scanning device 11091 and the Y-axis scanning device 11093; the optical path matching for different human eyes is achieved by the overall translation of the fiber collimating lens 1107 combined with the fiber optic head of the sample arm (not shown); the refractive adjustment for different human eyes is achieved by the translation of the eyepiece objective lens 1305 along the optical axis; finally, the acquisition of OCT images of the posterior segment of the eye is achieved, thereby obtaining important parameters of the eye structure such as retinal thickness.

[0085] (3) Anterior segment OCT imaging system

[0086] like Figure 2 The diagram shown is the optical path of the anterior segment OCT imaging system. The posterior segment OCT imaging adjustment optical path unit and the anterior segment OCT insertion lens 1501 form the anterior segment OCT imaging adjustment optical path unit. Specifically, the anterior segment OCT imaging adjustment optical path unit includes a fiber optic collimator 1107, a posterior segment OCT field lens 1301, an anterior segment OCT insertion lens 1501, a front beam splitter 1303, and an eyepiece objective lens 1305. Anterior segment OCT imaging can be performed through the cooperation of the optical path scanning device 1109 and the anterior segment OCT imaging adjustment optical path unit.

[0087] During anterior segment OCT imaging, the light emitted from the fiber optic collimator 1107 is reflected by the optical path scanning device 1109, transmitted through the posterior segment OCT field lens 1301 and the anterior segment OCT insertion lens 1501, reflected by the front beam splitter 1303, and then transmitted through the eyepiece objective lens 1305, finally converging onto the anterior segment (i.e., the cornea) of the subject eye E. The probe beam of the anterior segment OCT imaging optical path system satisfies the requirement that the OCT beam is focused on the anterior segment of the eye.

[0088] At this time, the anterior segment OCT insertion mirror 1501 is inserted into the optical path under the control of the computer 1143.

[0089] When measuring the anterior and posterior surfaces of the cornea and lens, the OCT beam is focused on the middle region of the anterior segment, which can effectively improve the signal-to-noise ratio and lateral resolution of the OCT image during the measurement of the anterior and posterior surfaces of the cornea and lens.

[0090] When measuring anterior segment OCT images, scanning is performed using the optical path scanning device 1109; optical path matching required for OCT measurement is achieved through the overall translation of the fiber collimating lens 1107 combined with the sample arm fiber optic head (not shown); focusing is achieved by translating the eyepiece objective lens 1305 along the optical axis L1, or by translating the entire probe module 10 along the optical axis L1. Through the cooperation of the optical path scanning device 1109 and the anterior segment OCT imaging adjustment optical path unit, OCT images of the anterior and posterior surfaces of the cornea and lens can be obtained, thereby obtaining important parameters of human eye structures such as anterior and posterior corneal curvature, corneal thickness, anterior chamber depth, lens thickness, and anterior and posterior lens curvature.

[0091] (4) Anterior segment camera module

[0092] As shown in FIG. 4A and FIG. 4B, they are the front view and top view of the anterior segment camera module, respectively. Figure 4a Figure 4b As shown in FIG. 4A and FIG. 4B, they are the front view and top view of the anterior segment camera module, respectively.

[0093] The module can be used for iris preview, so as to guide the doctor to operate the instrument, and make the probe light path align with the to-be-measured human eye. Or through automatic identification of the iris center or the pupil center position, it is used for guiding the probe module 10 to automatically move in three dimensions, so as to realize the alignment of the to-be-measured human eye pupil, and thus realize the detection of the to-be-measured human eye.

[0094] The light emitted by the illumination light source 1901 (infrared light) irradiates the anterior chamber of the to-be-measured human eye E, and the light is reflected by the anterior chamber tissue. The reflected light passes through the objective lens 1305, the front beam splitter 1303, the iris relay lens 1903, and the iris beam splitter 1905, and is finally captured by the anterior segment camera 1909.

[0095] The examiner fixes the head of the to-be-measured person by using the chin rest device (not shown in the figure), and makes the to-be-measured person fix the fixation mark of the fixation system, so as to fix the eyes of the to-be-measured person. Then, the examiner controls the movement of the chin rest device and the probe 10 by observing the display screen of the computer 1143 through the operating rod, so as to make the anterior segment of the to-be-measured eye E enter the anterior segment camera 1909, and the anterior segment image is displayed on the display screen of the computer 1143. Or through automatic identification of the iris center or the pupil center position, it is used for guiding the probe 10 to automatically move in three dimensions, so as to realize the alignment of the to-be-measured human eye pupil, and thus realize the detection of the to-be-measured human eye.

[0096] Through the anterior segment camera module 190, the important parameters of the human eye structure such as the white-to-white distance and the pupil diameter can be obtained.

[0097] The distribution of the illumination light source 1901 in the above figure is only schematic, and other distribution modes can also be used in other embodiments, as long as the illumination light source 1901 irradiates the anterior segment of the to-be-measured human eye, and the number can be one or more.

[0098] The iris beam splitter 1905 transmits the illumination light from the illumination light source 1901 in the anterior segment camera module 190, and also reflects the fixation light from the fixation light source 1701 in the fixation optical module, and reflects the light from the anterior segment slit light source 1809 in the anterior segment slit imaging module.

[0099] (5) Anterior segment slit imaging module

[0100] As shown in FIG. 4A and FIG. 4B, they are the front view and top view of the anterior segment camera module, respectively. Figure 5 ​As shown, it is a schematic diagram of the anterior segment slit imaging module. The anterior segment slit imaging module includes the combination module 18, the front beam splitter 1303, the parallax relay lens 1903, the parallax beam splitter 1905, the angle beam splitter 1807, the anterior segment slit light source 1809, wherein the combination module 18 is composed of the objective lens 1305, the anterior segment slit imaging lens 1801 and the anterior segment slit imaging device 1803. The combination module 18 is driven by a motor (not shown in the figure, which is independent of the above-mentioned three motors controlled as a whole) and can move in the Z direction, so as to realize the refractive adjustment.

[0101] The anterior segment slit light source 1809 generates slit light or slit light through the knife edge or the slit. The slit light or slit light is reflected by the angle beam splitter 1807 and the parallax beam splitter 1905, transmitted through the parallax relay lens 1903 and the front beam splitter 1303, and then focused on the anterior segment of the eye to be measured through the objective lens 1305. The anterior segment slit light passes through the anterior segment tissue, is scattered by the cornea and the lens, and finally is captured by the anterior segment slit imaging device 1803.

[0102] The anterior segment slit imaging light path (including the anterior segment slit imaging lens 1801 and the anterior segment slit imaging device 1803) is preferably distributed below the objective lens 1305. If it is distributed on the left / right side of the probe 10 in the X direction, it is not conducive to the use of both eyes together, and if it is distributed above the objective lens 1305, it is easy to be blocked by the eyelid.

[0103] In some embodiments, the anterior segment slit imaging device 1803 is only used to capture the anterior segment slit image near the cornea position of the eye to be measured, the imaging range is small, but the imaging accuracy is high. Through the anterior segment slit image, the spatial position of the cornea can be accurately located. For example, the thickness of the cornea is about 550 um, and if the Z direction anterior segment slit imaging range is taken as 0.5-10 mm, the positioning accuracy of the cornea position can be effectively improved. In other embodiments, the imaging range of the anterior segment slit imaging device 1803 is increased, and the anterior chamber depth and even the lens thickness can be obtained.

[0104] In the embodiment, the anterior segment slit imaging light path is distributed at an oblique angle, so the anterior segment slit imaging module combined with the anterior segment imaging module can accurately identify the Z direction position of the eye to be measured, and combined with the collected posterior segment OCT image, the axial length of the eye to be measured can be obtained.

[0105] The angle beam splitter 1807 reflects the light emitted by the anterior segment slit light source 1809 in the anterior segment slit imaging module and transmits the fixation light emitted by the fixation light source 1701 in the fixation optical module.

[0106] (6) Fixation optical module

[0107] As shown in FIG. 1, it is a schematic diagram of the fixation optical module. The fixation light source 1701 in the fixation optical module is used for the fixation target (internal fixation target) of the to-be-measured human eye E. The light from the fixation light source 1701 passes through the fixation light path lens 1703 and the angle fixation beam splitter 1807, is reflected by the reflection of the rainbow fixation relay lens 1903 and the front beam splitter 1303, and then the light passes through the eye lens 1305 and is incident on the to-be-measured human eye E. Finally, the internal fixation target is projected to the fundus Er of the to-be-measured human eye E. Figure 6

[0108] The fixation light source 1701 can adopt a single-point LED, or an LCD screen, an OLED screen, or an LED array screen, etc.

[0109] When the posterior segment OCT imaging is performed, the clarity of the fixation point is different when different human eyes observe the fixation point, which causes discomfort to the measured person when the fixation is performed, which is not convenient for the fixation and fixation of the to-be-measured human eye E. Since the light path of the posterior segment OCT imaging passes through the eye lens 1305 after being adjusted, it can be focused on the fundus Er (fundus retina) of the to-be-measured human eye E, that is, the human eye can clearly see the scanning line. Since the posterior segment OCT imaging light path and the fixation light path share the eye lens 1305, the fixation target can be clearly seen by different human eyes.

[0110] (7) Measurement of axial length

[0111] Since the detection depth of the OCT system is limited, it is impossible to realize one-time imaging detection from the cornea to the fundus retina, so the embodiment combines the anterior segment slit imaging and the posterior segment OCT imaging technology, determines the cornea position of the to-be-measured human eye through the anterior segment slit imaging, and determines the fundus position of the to-be-measured human eye through the posterior segment OCT imaging, so as to realize the measurement of the axial length.

[0112] As shown in FIG. 2, Er represents the fundus of the to-be-measured human eye, Ec represents the corneal vertex of the to-be-measured human eye, X represents the change of the sample arm light path caused by the optical path adjustment device (including the optical fiber collimator 1107 and the optical fiber head not shown in the figure) when the posterior segment OCT image of the to-be-measured human eye is measured; CDK represents the spatial position corresponding to the top end of the anterior segment slit image; RDK1 represents the spatial position corresponding to the top end of the posterior segment OCT image when the optical path adjustment device is in the reset position; RDK2 represents the spatial position corresponding to the top end of the posterior segment OCT image when the optical path adjustment device changes the sample arm light path by X when the posterior segment OCT image of the to-be-measured human eye is measured; hCornea represents the optical path from the top end of the anterior segment slit image to the corneal vertex Ec of the to-be-measured human eye in the anterior segment slit image; hRetinal represents the optical path from the top end of the posterior segment OCT image to the retinal signal in the posterior segment OCT image. Figure 7 Figure 7 ​​The three rectangular frames shown in FIG. 6, wherein the left two represent the OCT measurement range of the posterior segment of the eye, and the rectangular frame is only illustrative, and the actual scanning area can be a fan-shaped structure; the right rectangular frame represents the anterior segment of the eye image photographed by the anterior segment of the eye imaging.

[0113] When the anterior segment of the eye image is photographed, the position at which the slit light generated by the anterior segment of the eye light source 1809 is focused and the spatial position or spatial range that can be photographed by the anterior segment of the eye imaging light path are determined during system debugging, that is, Figure 7 The spatial distance from the spatial position CDK corresponding to the top of the anterior segment of the eye image to the objective lens 1305 is determined during system debugging; therefore, if the eye to be measured moves slightly forward and backward but does not exceed the imaging range of the anterior segment of the eye, the spatial position of the cornea can be determined by identifying the position of the cornea photographed in the anterior segment of the eye image.

[0114] When the posterior segment of the eye OCT image is measured, since the axial length of the human eye is not the same, but the reference arm length of the OCT system is fixed, the following methods are used in the embodiment to measure the retina at different depths: (a) by adding an optical path adjustment device, the equal interference surface of the posterior segment of the eye OCT imaging is moved; (b) the whole optical fiber collimator 1107 and the sample arm optical fiber head are translated along the optical axis; (c) a right-angle prism or a corner cube prism is added to make the light path turn multiple times, and then the right-angle prism or the corner cube prism is translated to change the optical path. The above three methods can be used simultaneously or selectively.

[0115] The OCT system finds the posterior segment of the eye retina signal, and the optical path change amount of the optical path adjustment device relative to the reset position is X. That is, when the optical path adjustment device changes the sample arm optical path distance by X, the spatial position corresponding to the top of the posterior segment of the eye OCT image moves from RDK1 to RDK2, and the distance between RDK1 and RDK2 is X, as shown in FIG. 6. Figure 7

[0116] The optical path change amount X of the optical path adjustment device can be measured by various methods, such as a stepper motor, a voice coil motor, a grating ruler, a capacitive grating ruler, etc.

[0117] In addition, when the optical path adjustment device is in the reset position, the spatial distance from the spatial position RDK1 corresponding to the top of the posterior segment of the eye OCT image to the objective lens 1305 is determined during system debugging. Therefore, the spatial distance AL between RDK1 (the spatial position corresponding to the top of the posterior segment of the eye OCT image) and CDK (the spatial position corresponding to the top of the anterior segment of the eye image) is determined during system debugging.

[0118] Therefore, by measuring the posterior segment of the eye OCT image and the anterior segment of the eye imaging, the axial length Leye of the human eye can be obtained: ​

[0119] Leye = AL + X - hCornea + hRetinal,

[0120] In the formula, hCornea can be measured from the anterior segment slit image, and hRetinal can be measured from the posterior segment OCT image.

[0121] Since the axial lengths of different human eyes are different, in order to measure the anterior and posterior segments of the human eye E to be measured, the optical path of the sample arm or the reference arm needs to be changed to realize OCT coherent imaging (in this embodiment, the sample arm optical path is changed as an example). Changing the optical path also needs to meet the detection depth of the OCT system and the different axial lengths of different human eyes, so accurate positioning is required, and it is often difficult to realize fast switching to change the optical path. For example, by using an optical path adjusting device, relying on the translation of the motor, it is impossible to realize fast switching to meet the optical path requirements of measuring the positions of the anterior and posterior segments of the human eye. Therefore, in this embodiment, the anterior segment slit imaging combined with the posterior segment OCT imaging scheme is used to measure the axial length of the human eye to be measured.

[0122] Since the anterior segment slit imaging and the posterior segment OCT imaging use different imaging schemes (without the need for the OCT system to switch the optical paths of the anterior and posterior segments of the eye), the two can be simultaneously imaged, thereby avoiding the influence of the eye movement of the human eye to be measured, and improving the measurement accuracy of the axial length of the eye.

[0123] In this embodiment, the determination of the corneal position uses anterior segment slit imaging, and the recognition of the fundus position uses posterior segment OCT imaging technology. The two can work and image at the same time, and there is no switching of the imaging time, so the influence of the eye movement can be effectively avoided, and more accurate axial length data of the eye can be obtained. Moreover, the anterior and posterior segment images are collected at one time, which is beneficial to the operation of the doctor, improves the diagnosis speed, and improves the interactive experience of the doctor and the patient. In addition, one measurement realizes the detection of many key parameters of the human eye such as the corneal position, the anterior chamber depth, the axial length of the eye, the corneal curvature, and the white to white. It has many advantages such as cost, speed, accuracy, and multi-function.

[0124] Embodiment Two

[0125] As Figure 8As shown, the ophthalmic optical biometric system disclosed in the second embodiment of the present application differs from the first embodiment in that the second embodiment cancels the anterior segment slit light source 1809 and the goniosplitting beam splitter 1807. In the second embodiment, the light emitted by the OCT light source 1101 is coupled by the fiber coupler 1103, the polarization controller 1105, and then output by the fiber collimator 1107. The light beam is scanned by the optical path scanning device 1109, passes through the posterior segment OCT field lens 1301 and the anterior segment OCT insertion lens 1501, is reflected by the pre-splitting beam splitter 1303, is transmitted by the objective lens 1305, and is finally focused on the anterior segment of the human eye to be measured. Due to one-dimensional scanning of the optical path scanning device 1109, the slit light incident on the human eye to be measured is formed. The slit light of the anterior segment formed by the light source (OCT light source 1101) in the anterior segment OCT imaging system passes through the cornea, is scattered by the cornea, the scattered light passes through the anterior segment slit imaging lens 1801, and is finally captured by the anterior segment slit imaging device 1803, thereby forming an anterior segment slit image, as shown in Figure 9

[0126] Since the axial length of the human eye is often longer than the detection depth of the OCT system, when switching from the anterior segment OCT to the posterior segment OCT, the optical path length of the sample arm or the reference arm of the OCT system often needs to be adjusted at the same time, so that the OCT detection light incident on the anterior segment of the human eye and the reference arm satisfy the coherence length, or the OCT detection light incident on the posterior segment of the human eye and the reference arm satisfy the coherence length. Therefore, the OCT system often needs to switch and change the optical path length. In the first embodiment, the fiber collimator 1107 is connected to the sample arm fiber, and the whole is driven by a motor to move along the optical axis, thereby changing the optical path length of the sample arm. However, due to the long stroke (the axial length of the human eye), this motion mode for changing the optical path length needs to be matched for different axial lengths of different human eyes, and therefore the switching speed is slow. However, in the first embodiment, the axial length of the eye is measured by combining the anterior segment slit imaging and the posterior segment OCT simultaneous detection, thereby avoiding the influence of eye movement. In the second embodiment, the device cost is saved, the anterior segment slit light source module uses the OCT light source module 1101 and the optical path scanning device 1109 to generate slit light, thereby providing a slit illumination light source. When measuring the axial length of the eye, the insertion or withdrawal of the anterior segment OCT insertion lens 1501 is used to switch the posterior segment OCT imaging adjustment optical unit and the anterior segment OCT imaging adjustment optical unit; however, the axial length of the eye is still detected by using the anterior segment slit imaging combined with the posterior segment OCT imaging, and only the light source of the anterior segment slit imaging is changed to the OCT light source 1101. Therefore, when measuring the axial length of the eye in the second embodiment, there is a short switching time, i.e., the insertion of the anterior segment OCT insertion lens 1501. However, since the insertion of the anterior segment OCT insertion lens 1501 only needs to be finally positioned, it does not need to move a different length for different axial lengths of different human eyes as the optical path adjustment device does, and therefore the switching speed can be greatly improved, for example, by using an electromagnet to switch. ​

[0127] In this embodiment, there is no need to add an anterior segment slit light source 1809 and an angle-beam splitter 1807. The existing OCT light source module 1101 and optical path scanning device 1109 are used to generate anterior segment slit illumination light, which is then focused on the anterior segment of the subject after passing through the anterior segment OCT imaging adjustment optical path unit. Compared with Embodiment 1, although the number of light source components is reduced, the switching from posterior segment OCT to anterior segment slit imaging requires the insertion of an anterior segment OCT insert lens 1501, resulting in a slight switching time. In addition, the one-dimensional scanning of the optical path scanning device 1109 to form slit light also requires a slight scanning time. However, since there is no need for a translational optical path adjustment device, the above time is faster than the solution in the prior art (e.g., the time required for the switching process between anterior and posterior segment OCT in prior art patent document 202011120798.5 includes the insertion of the anterior segment OCT insert lens and the time for the optical path adjustment device to change the optical path translation for the anterior and posterior segments of the subject's eye E), and it is easier to avoid the influence of eye movement during long-term axial length measurement.

[0128] Compared to Example 1, Example 2 does not require additional debugging of one optical path (anterior segment slit illumination optical path), thus reducing the difficulty of system debugging and increasing the system debugging speed.

[0129] In this second embodiment, the optical path of the OCT light source 1101 combined with the optical path scanning device 1109 is used to realize the function of the anterior segment slit light source without increasing hardware costs.

[0130] This embodiment differs from Embodiment 1 except for the anterior segment slit imaging module. It can be understood that the fixation optics module in this embodiment no longer includes the angle-beam splitter 1807. Figure 10 As shown, the other structures and principles are the same, and will not be described in detail here.

[0131] Example 3

[0132] like Figure 11 As shown, the ophthalmic optical biometry system disclosed in Embodiment 3 of the present invention, compared with Embodiment 2, does not use the OCT light source 1101 as the anterior segment slit light source in this embodiment. Instead, a wavelength division multiplexer 3807 couples the probe light input from the fiber coupler 1103 into the OCT sample arm with the light output from the anterior segment slit light source 3809 into the optical fiber 1106, and then outputs it through the sample arm fiber optic head (not shown in the figure). In this embodiment, the anterior segment slit light source module uses the anterior segment slit light source 3809, the wavelength division multiplexer 3807, the optical fiber 1106, and the optical path scanning device 1109 to generate slit light. The light output from the anterior segment slit light source 3809 is coupled by the wavelength division multiplexer 3807 and transmitted to the optical fiber 1106. The beam output from the optical fiber 1106 is scanned in one dimension by the optical path scanning device 1109 and then emits slit light, which passes through the anterior segment OCT imaging adjustment optical path unit and is focused on the anterior segment of the subject.

[0133] The optical fiber 1106 is not limited to a single-mode optical fiber or a multi-mode optical fiber. As shown in the figure, the optical fiber 1106 has a core 11061, the core 11061 is surrounded by a cladding 11063, and the cladding 11063 is surrounded by a sheath 11065, which protects the optical fiber. Figure 12

[0134] As shown in the figure, the difference between the posterior segment OCT imaging light path in the embodiment and the posterior segment OCT imaging light path in the first embodiment is that the light emitted by the OCT light source 1101 is transmitted to the wavelength division multiplexer 3807 through the optical fiber coupler 1103 and the polarization controller 1105, and then is transmitted through the optical fiber 1106. Figure 13

[0135] As shown in the figure, the difference between the anterior segment OCT imaging light path in the embodiment and the anterior segment OCT imaging light path in the first embodiment is that the light emitted by the OCT light source 1101 is transmitted to the wavelength division multiplexer 3807 through the optical fiber coupler 1103 and the polarization controller 1105, and then is transmitted through the optical fiber 1106. Figure 14

[0136] As shown in the figure, the difference between the anterior segment slit imaging light path in the embodiment and the anterior segment slit imaging light path in the second embodiment is that the light emitted by the anterior segment slit light source 3809 is transmitted to the optical fiber 1106 through the wavelength division multiplexer 3807, and then is transmitted through the optical fiber 1106. The light is emitted through the sample arm optical fiber head (not shown in the figure), and then is output through the optical fiber collimating mirror 1107. The light beam is scanned by the light path scanning device 1109, passes through the posterior segment OCT field lens 1301 and the anterior segment OCT insertion lens 1501, is reflected by the pre-splitting mirror 1303, is transmitted through the objective lens 1305, and finally converges on the anterior segment of the eye to be measured. Due to the one-dimensional scanning of the light path scanning device 1109, the slit light is incident on the eye to be measured. The light source in the anterior segment OCT imaging system (the anterior segment slit light formed by the OCT light source 1101 and the anterior segment slit light source 3809) passes through the cornea, is scattered by the cornea, the scattered light passes through the anterior segment slit imaging lens 1801, and finally is captured by the anterior segment slit imaging device 1803, thereby forming an anterior segment slit image. Figure 15

[0137] ​​​​The ophthalmic optical biometric system of the present embodiment needs a relatively short switching scanning time when measuring the axial length of the eye, and does not need a horizontal light path adjustment device, so the switching scanning time is relatively short. In addition, the probe light input from the fiber coupler 1103 to the OCT sample arm is coupled into the optical fiber 1106 by the wavelength division multiplexer 3807 together with the light output by the anterior segment slit light source 3809. Compared with the second embodiment, the anterior segment slit light source 3809 can use a light source of a different wavelength band. Since the OCT light source 1101 generally uses near-infrared light, the scattering coefficient of the anterior segment tissue of the near-infrared light is relatively small. In the present embodiment, the anterior segment slit light source 3809 can use a short-wave wavelength band, such as a blue light wavelength band, to improve the scattering coefficient of the anterior segment tissue, thereby improving the imaging effect of the anterior segment slit.

[0138] Compared with the first embodiment, the present embodiment does not need to additionally adjust one light path (anterior segment slit illumination light path), so the system adjustment difficulty can be reduced and the system adjustment speed can be improved.

[0139] Embodiment Four

[0140] As shown in Figure 16 the fourth embodiment of the present application discloses an ophthalmic optical biometric system. Compared with the third embodiment, in the present embodiment, the probe light input from the fiber coupler 1103 to the OCT sample arm and the light output by the anterior segment slit light source 4809 enter the parallel optical fiber 2106, and then exit through the sample arm optical fiber head (not shown in the figure). In the present embodiment, the anterior segment slit light source module uses the anterior segment slit light source 4809, the parallel optical fiber 2106, and the light path scanning device 1109 to generate slit light. The light output by the anterior segment slit light source 3809 passes through the parallel optical fiber 2106, and the light beam output by the parallel optical fiber 2106 is emitted after one-dimensional scanning by the light path scanning device 1109, and then focused on the anterior segment of the eye to be measured after passing through the anterior segment OCT imaging adjustment light path unit.

[0141] As shown in Figure 17As shown, the parallel optical fiber 2106 has an OCT optical path core 21061 and an anterior segment slit illumination optical path core 21062. The OCT optical path core 21061 is used to transmit the probe light input from the optical fiber coupler 1103 into the OCT sample arm, and the OCT optical path core 21061 is wrapped by the OCT optical path cladding 21063. The anterior segment slit illumination optical path core 21062 is used to transmit the light output from the anterior segment slit light source 4809, and the anterior segment slit illumination optical path core 21062 is wrapped by the anterior segment slit illumination fiber cladding 21064. The OCT optical path cladding 21063 and the anterior segment slit illumination fiber cladding 21064 are arranged in parallel and are wrapped together by a sheath 21065. Parallel optical fibers 2106 share a single fiber optic connector (not shown in the figure). The probe light from the OCT sample arm and the light output from the anterior segment slit illumination source 4809 of the transmission eye are input from the fiber coupler 1103, and after passing through the fiber optic connector, they enter the optical path of the OCT sample arm module. This shared fiber optic connector forms two light-emitting sources, and the distance between these two sources is the distance d between the OCT optical path fiber core 21061 and the anterior segment slit illumination optical path fiber core 21062. A smaller distance d is better. When d is small, the parallel optical fibers 2106 sharing a single sample arm fiber optic connector can emit light from approximately one light-emitting point. After passing through the optical path of the OCT sample arm module 130, the distance between the two probe points when incident on the eye under test will also be smaller.

[0142] Compared to traditional dual-core fiber 3106 (such as...) Figure 18 As shown, the fiber cores 31061 / 31062 are wrapped by fiber cladding 31063 / 31064, then by sheaths 31065 / 31066, and finally by a large sheath 31069. In this configuration, the spacing d3 between the two fiber cores is often quite large. Consequently, the light emitted from the two fiber cores 31061 / 31062 cannot be approximated by a single emission point. Therefore, when the light enters the eye of the person being tested after passing through the optical path of the OCT sample arm module 130, the distance between the two detection points will also be relatively large.

[0143] Therefore, the optical path for OCT imaging of the posterior segment and the optical path for OCT imaging of the anterior segment in this embodiment are similar to those in Embodiment 1 or Embodiment 2. The only difference is that the probe light input from the optical fiber coupler 1103 into the OCT optical path core 21061 in the parallel optical fiber 2106, and then exits through the optical fiber head of the sample arm (not shown in the figure).

[0144] like Figure 19As shown, in the anterior segment slit imaging optical path in this embodiment, the anterior segment slit light source 4809 emits light into the parallel optical fiber 2106, is transmitted through the anterior segment slit illumination optical path fiber core 21062, and then emits light through the common optical fiber head (not shown in the figure) and is output through the fiber collimating mirror 1107. After being scanned by the light beam scanning device 1109, the light beam passes through the posterior segment OCT field lens 1301, the anterior segment OCT insertion lens 1501, is reflected by the pre-splitting mirror 1303, is transmitted through the objective lens 1305, and is finally focused on the anterior segment of the human eye to be measured. Due to one-dimensional scanning of the light path scanning device 1109, the slit light is formed to be incident on the human eye to be measured. The slit light formed by the light source (OCT light source 1101) and the anterior segment slit light source 4809 in the anterior segment OCT imaging system passes through the cornea, is scattered by the cornea, the scattered light passes through the anterior segment slit imaging lens 1801, and is finally captured by the anterior segment slit imaging device 1803, so as to form an anterior segment slit image.

[0145] When the ophthalmic optical bio-measurement system in this embodiment is used to measure the axial length, a relatively short switching scanning time is required, and the translation optical path adjustment device is not required, so the switching scanning time is short. In addition, the probe light input from the optical fiber coupler 1103 into the OCT sample arm and the light output by the anterior segment slit light source 4809 are input into the parallel optical fiber 2106 in parallel. Compared with the second embodiment, the anterior segment slit light source 4809 can use light sources of different wavebands. Since the OCT light source 1101 generally uses near-infrared light, the scattering coefficient of the anterior segment tissue of the near-infrared light is small. In this embodiment, the anterior segment slit light source 3809 or the anterior segment slit light source 4809 can use a short-wave waveband, such as a blue light waveband, so as to improve the scattering coefficient of the anterior segment tissue and improve the anterior segment slit imaging effect.

[0146] Embodiment five

[0147] Reference Figures 20-21 The anterior segment camera module 190 and the fixation optical module of the ophthalmic optical bio-measurement system disclosed in the fifth embodiment of the present application are the same as those in the second embodiment.

[0148] Posterior segment OCT sample arm module: The posterior segment OCT sample arm module includes a light path scanning device 1109 and an anterior segment OCT imaging adjustment optical path unit. Compared with the first embodiment or the second embodiment, the light emitted from the fiber collimating mirror 1107 is first reflected by the light splitting mirror 5805 and then reflected by the light path scanning device 1109.

[0149] Anterior segment slit imaging: the anterior segment slit imaging adjustment light path module adopts the posterior segment OCT imaging adjustment light path unit. Compared with the anterior segment slit imaging light path of the third / fourth embodiments, in the fifth embodiment, the anterior segment slit light source module includes an anterior segment slit light source 5809, a lens 5807, and a beam splitter 5805. The anterior segment slit light source 5809 emits light, which passes through the lens 5807, is reflected by the beam splitter 5805, is reflected by the light path scanning device 1109, passes through the posterior segment OCT imaging adjustment light path unit (passes through the posterior segment OCT field lens 1301, is reflected by the front beam splitter 1303, and is transmitted to the objective lens 1305), and finally converges to the human anterior segment. Due to one-dimensional scanning of the light path scanning device 1109, the slit light is incident on the eye to be measured. The anterior segment slit light formed by the anterior segment slit light source 5809 passes through the cornea, is scattered by the cornea, passes through the anterior segment slit imaging lens 1801, and is finally captured by the anterior segment slit imaging device 1803, thereby forming an anterior segment slit image. The lens 5807 in this embodiment plays a similar role to the anterior segment OCT insertion lens 1501 in the foregoing embodiments.

[0150] The anterior segment slit light generation light path of this embodiment utilizes the light path scanning device 1109 (without the need to add a scanning mechanism) to achieve scanning, thereby simplifying the generation of slit light. At this time, the degree of freedom of the arrangement of the light path is higher, such as the anterior segment slit light source 1809 in the first embodiment. In other embodiments, if the light path scanning device 1109 is not utilized, the anterior segment slit light source 5809 needs to emit slit light, also known as slit light. At this time, the light source needs to add a knife-edge mechanical structure to obtain a very sharp line light source.

[0151] Compared with the first embodiment, the second, third, and fourth embodiments do not need to additionally adjust one light path (anterior segment slit illumination light path), thereby reducing the difficulty of system adjustment and improving the speed of system adjustment.

[0152] Compared with the third embodiment, the fourth embodiment does not need to add the wavelength division multiplexer 3807, but the parallel optical fiber 2106 is a non-traditional optical fiber and needs to be specially processed and manufactured.

[0153] In the third and fourth embodiments, the probe light of the OCT sample arm and the anterior segment slit light are coupled or output in parallel, and then enter the light path of the light path scanning device 1109 and the posterior segment OCT imaging adjustment light path unit together, so that the light paths of the two are basically parallel, which greatly reduces the adjustment difficulty of the two light paths.

[0154] In the scheme of measuring the axial length of the eye, the switching of the light source can be realized by the electric control of the light source, as in the scheme of embodiment three / embodiment four. Only a short scanning time is needed, and the translation optical path adjusting device is not needed. The imaging of the anterior segment slit image and the OCT imaging of the posterior segment of the eye can be carried out at the same time, so that the influence of the eye movement can be effectively avoided, and the real-time performance and the accuracy of the measurement of the axial length of the eye are improved.

[0155] The ophthalmic optical biometric system designed in the application can realize the measurement of different depths of the object, improve the detection range of the OCT system (anterior segment imaging and posterior segment imaging), and has stable switching system and accurate positioning, and does not affect the signal-to-noise ratio of the system. The system can also realize the focusing of the light beam at different positions, and can realize the high-quality OCT imaging of different parts of the eye of a person with different vision, and has high lateral resolution. The anterior segment imaging OCT system and the posterior segment imaging OCT system can obtain a plurality of parameter data of the human eye, such as the corneal curvature, the corneal thickness, the anterior chamber depth, the lens thickness, the lens surface curvature, the white-to-white distance, the pupil diameter, etc. The anterior segment camera imaging and the automatic recognition technology can assist the automatic detection of the instrument. Through the iris recognition technology, the anterior segment OCT image automatic recognition technology, the posterior segment OCT image automatic recognition technology, etc., the full-automatic detection of the system is realized. The imaging of the anterior segment slit image is carried out at the same time as the imaging of the posterior segment OCT image of the eye, so that the accurate axial length data of the eye are obtained. The ophthalmic optical biometric system and the method for measuring the axial length of the eye provided in the application have the following characteristics:

[0156] (a) The probe light path needs to realize the OCT imaging of different parts of the human eye to be measured, but the focusing positions used by them are different, so the light paths used for the measurement should be different. The OCT light beam needs to be parallelly incident on the human eye (for emmetropia) when the posterior segment OCT imaging is carried out; and the OCT light beam needs to be focused on the anterior segment of the human eye when the anterior segment OCT imaging is carried out. The design is beneficial to improving the imaging quality of the anterior segment OCT and the posterior segment OCT.

[0157] (b) The equal optical path surface is located at the retina of the human eye to be measured when the posterior segment OCT imaging is carried out, and the equal optical path surface is located at the anterior segment of the human eye to be measured when the anterior segment OCT imaging is carried out, so the light path for the OCT imaging of different parts does not need to be adjusted by adjusting the optical path of the reference arm.

[0158] (c) The refractive compensation can be carried out for the human eyes with different vision, and the imaging of different parts of the human eye can be realized.

[0159] (d) The fixation light path of the human eye can be realized to satisfy the fixation of the left eye and the right eye.

[0160] (e) The anterior segment camera imaging light path, combined with the iris automatic recognition technology, can be used to guide the movement of the probe module, so that the detection of the human eye to be measured is realized. The obtained iris image can be used to measure the pupil diameter and the white-to-white distance and other parameters.

[0161] (f) fast and accurate switching device, realizing fast OCT imaging of different parts of human eye.

[0162] (g) on the basis of OCT imaging of different parts of human eye, fast and accurate measurement of axial length, anterior chamber depth, lens thickness, etc. can be realized without moving the reference arm.

[0163] (h) fast switching of anterior and posterior segments, less motion mechanism, low cost.

[0164] (i) the fixation light path and the posterior segment OCT share the refractive adjustment device, reducing the moving parts of the fixation light path, and realizing the confocal of the fixation light path and the posterior segment OCT light path, which is conducive to the fixation of the measured human eye and the acquisition of the posterior segment OCT image.

[0165] (j) through the anterior segment slit imaging, the accurate positioning of the cornea is obtained.

[0166] (k) using frequency domain optical coherence tomography technology, compared with time domain system, the scanning imaging speed is fast, the imaging resolution is high, but the detection depth is shallow; compared with scanning frequency domain optical coherence tomography technology, the scanning speed, resolution, etc. are equivalent, the cost is much lower, but the detection depth is shallow.

[0167] (l) low-cost fast switching scanning scheme, realizing anterior and posterior segment OCT imaging. Combined with anterior segment camera and automatic recognition technology, automatic detection of the measured human eye is realized. In addition, the principle is to use optical coherence tomography technology, which is theoretically unlimited frequency domain, sweep frequency, and even time domain system.

[0168] The above is a further detailed description of the present application in combination with the preferred embodiment, which cannot be considered as the specific implementation of the present application only limited to these descriptions. For those skilled in the art to which the present application belongs, without departing from the concept of the present application, a number of equivalent alternatives or obvious variations can be made, and the performance or use is the same, which should be considered as belonging to the protection scope of the present application.

Claims

1. An optical system for measuring axial length of an eye, characterized by, The device comprises an OCT light source module, an OCT imaging module, an ocular posterior segment OCT sample arm module, and an anterior segment slit imaging assembly, wherein: The OCT light source module is configured to provide measurement light, which, after passing through the ocular posterior segment OCT sample arm module, is incident on the fundus of an eye to be measured, and the OCT imaging module receives the measurement light returned from the fundus of the eye to be measured to obtain an ocular posterior segment OCT image. The anterior segment slit imaging assembly comprises an anterior segment slit light source module, an anterior segment slit imaging module, and an anterior segment slit imaging adjustment optical path module, the anterior segment slit light source module is configured to provide slit light, which, after passing through the anterior segment slit imaging adjustment optical path module, is focused on the anterior segment of the eye to be measured, and the anterior segment slit imaging module receives the returned slit light to obtain an anterior segment slit image. The ocular axial length is calculated using first optical path data and second optical path data obtained from the ocular posterior segment OCT image and the anterior segment slit image. The ocular posterior segment OCT sample arm module comprises an optical path scanning device (1109) and an ocular posterior segment OCT imaging adjustment optical path unit, the ocular posterior segment OCT imaging adjustment optical path unit and an anterior segment OCT insertion lens (1501) form an anterior segment OCT imaging adjustment optical path unit, and the anterior segment slit imaging adjustment optical path module uses the anterior segment OCT imaging adjustment optical path unit.

2. The optical system of claim 1, wherein The anterior segment slit imaging module comprises an anterior segment slit imaging lens (1801) and an anterior segment slit imaging device (1803), the slit light emitted by the anterior segment slit light source module is focused on the anterior segment of the eye to be measured, and the returned anterior segment slit light signal passes through the anterior segment slit imaging lens (1801) and is received by the anterior segment slit imaging device (1803), the anterior segment slit imaging device (1803) obtains an anterior segment slit image according to the anterior segment slit light signal.

3. The optical system of claim 2, wherein, The anterior segment slit imaging adjustment optical path module comprises an eye objective lens (1305), which is located on a first direction optical path perpendicular to the eye to be measured, and the anterior segment slit imaging lens (1801) and the anterior segment slit imaging device (1803) are arranged below the eye objective lens (1305) respectively.

4. The optical system of claim 1, wherein The anterior segment slit light source module uses the OCT light source module and the optical path scanning device (1109) to generate slit light, wherein the measurement light provided by the OCT light source module passes through one-dimensional scanning of the optical path scanning device (1109) to emit slit light, and the slit light passes through the anterior segment OCT imaging adjustment optical path unit and is focused on the anterior segment of the eye to be measured.

5. The optical system of claim 1, wherein The anterior segment slit light source module generates slit light by using an anterior segment slit light source (3809), a wavelength division multiplexer (3807), an optical fiber (1106) and the optical path scanning device (1109). The light output by the anterior segment slit light source (3809) is coupled by the wavelength division multiplexer (3807) and then transmitted into the optical fiber (1106). The light beam output from the optical fiber (1106) is scanned by the optical path scanning device (1109) in one dimension, and then emits slit light and focuses on the anterior segment of the human eye to be measured after passing through the anterior segment OCT imaging adjustment optical path unit.

6. The optical system of claim 1, wherein, The posterior segment OCT imaging adjustment optical path unit includes a posterior segment OCT field lens (1301), a front-mounted beam splitter (1303) and an objective lens (1305). The measurement light provided by the OCT light source module is reflected by the optical path scanning device (1109), passes through the posterior segment OCT field lens (1301), is reflected by the front-mounted dichroic mirror (1303) to the objective lens (1305), and is focused on the fundus of the human eye to be measured to return the posterior segment light signal to the OCT imaging module. The OCT imaging module acquires a posterior segment OCT image according to the posterior segment light signal.

7. The optical system according to any one of claims 4 to 6, characterized in that The first optical path data refers to the optical path hRetinal from the top of the posterior segment OCT image to the retinal signal in the posterior segment OCT image of the human eye to be measured, and the second optical path data refers to the optical path hCornea from the top of the anterior segment slit image to the vertex of the cornea of the human eye to be measured. The first optical path data refers to the optical path hRetinal from the top of the posterior segment OCT image to the retinal signal in the posterior segment OCT image of the human eye to be measured, and the second optical path data refers to the optical path hCornea from the top of the anterior segment slit image to the vertex of the cornea of the human eye to be measured.

8. The optical system of claim 1, wherein, ​ The axial length of the eye is calculated using the first optical path data and the second optical path data, including: according to the posterior segment OCT image of the measured eye, the change X of the optical path of the posterior segment OCT sample arm module, and the measured optical path hRetinal and the optical path hCornea, the axial length Leye of the measured eye is calculated.

9. A method of measuring axial length of an eye, characterized by, The optical system of any one of claims 1 to 8 is used to measure the axial length of the eye, including the following steps: an eye posterior segment OCT image of the measured eye is obtained, so that the optical path hRetinal from the top of the eye posterior segment OCT image to the retinal signal in the eye posterior segment OCT image is measured according to the eye posterior segment OCT image of the measured eye; an anterior segment slit image of the measured eye is obtained, so that the optical path hCornea from the top of the anterior segment slit image to the vertex of the cornea of the measured eye is measured according to the anterior segment slit image of the measured eye; the axial length Leye of the measured eye is calculated according to the posterior segment OCT image of the measured eye, the change X of the optical path of the posterior segment OCT sample arm module, and the measured optical path hRetinal and the optical path hCornea.

10. The method of claim 9, wherein, The axial length Leye of the measured eye is calculated using the following formula: Leye=△L+X-hCornea+hRetinal; wherein △L represents the spatial distance between the top of the posterior segment OCT image and the top of the anterior segment slit image, and X represents the change of the optical path of the posterior segment OCT sample arm module when the posterior segment OCT image of the measured eye is obtained.

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