Ophthalmic device and ophthalmic treatment program

Abstract

To provide information that enables more appropriate evaluation of the ocular refractive power state of a subject's eye. [Solution] The device comprises a first anterior eye information acquisition means for acquiring first anterior eye shape information of the test eye in a state of no accommodation or a state equivalent to no accommodation, an eye refractive power acquisition means for acquiring first eye refractive power measured by an eye refractive power measurement means that measures the eye refractive power of the test eye, a second anterior eye information acquisition means for acquiring second anterior eye shape information of the test eye when the first eye refractive power is measured, a processing means for performing at least one of the following processes based on all or part of the acquired first eye refractive power, first anterior eye shape information, and second anterior eye shape information: a process for determining whether or not accommodative intervention is required when measuring the eye refractive power of the test eye by the eye refractive power measurement means; a process for determining the second eye refractive power of the test eye in a state of no accommodation; and a process for determining the amount of accommodative intervention when measuring the eye refractive power of the test eye by the eye refractive power measurement means; and an output means for outputting the processing results of the processing means.

Description

[Technical Field]

[0001] The present disclosure relates to an ophthalmic apparatus and an ophthalmic processing program for obtaining the ocular refractive power of a subject's eye. [Background technology]

[0002] Known ophthalmic devices include an eye refractive power measurement device equipped with an eye refractive power measurement optical system that objectively measures the eye refractive power of a subject's eye by projecting measurement light onto the fundus of the subject's eye and receiving the reflected light of the measurement light from the fundus (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-072593 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-249768 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in objective eye refractive power measurement such as that in Patent Document 1, if the eye to be examined is not sufficiently fogging, the measurement result may be the eye refractive power measured in an accommodation intervention state (a state in which eye accommodation is intervened). For this reason, for example, when managing the progression of refractive error of the eye to be examined, it cannot be said that the eye refractive power state of the eye to be examined can be appropriately evaluated only with the measurement result obtained by the eye refractive power measurement device.

[0005] In view of the above-described conventional techniques, the present disclosure has as its technical object to provide an ophthalmic apparatus and an ophthalmic processing program that can provide information that allows for more appropriate evaluation of the ocular refractive power state of a subject's eye. [Means for solving the problem]

[0006] (1) The ophthalmic device disclosed herein is characterized by comprising a first anterior ocular segment information acquisition means for acquiring first anterior ocular segment shape information of the subject's eye in a state of no accommodation or a state equivalent to no accommodation; an ocular refractive power acquisition means for acquiring first ocular refractive power measured by an ocular refractive power measurement means for measuring the ocular refractive power of the subject's eye; a second anterior ocular segment information acquisition means for acquiring second anterior ocular segment shape information of the subject's eye when the first ocular refractive power is measured by the ocular refractive power measurement means; a processing means for performing at least one of the following processes based on all or part of the acquired first ocular refractive power, the first anterior ocular segment shape information, and the second anterior ocular segment shape information: a process for determining whether or not accommodative intervention is required when the ocular refractive power of the subject's eye is measured by the ocular refractive power measurement means; a process for determining the second ocular refractive power of the subject's eye in a state of no accommodation; and a process for determining the amount of accommodative intervention when the ocular refractive power of the subject's eye is measured by the ocular refractive power measurement means; and an output means for outputting the processing results of the processing means. (2) The ophthalmic treatment program disclosed herein is an ophthalmic treatment program executed by a control unit of an ophthalmic device that obtains the ocular refractive power of a subject's eye, and includes a first anterior ocular segment information acquisition step of acquiring first anterior ocular segment shape information of the subject's eye in a non-accommodative state or a state equivalent to non-accommodative state; an ocular refractive power acquisition step of acquiring first ocular refractive power measured by an ocular refractive power measurement means that measures the ocular refractive power of the subject's eye; and a second anterior ocular segment information acquisition step of acquiring second anterior ocular segment shape information of the subject's eye when the first ocular refractive power is measured by the ocular refractive power measurement means. The method is characterized in that the ophthalmologic device is caused to perform at least one of the following processing steps: a process for determining whether or not accommodative intervention is required when the ocular refraction of the test eye is measured by the ocular refraction measurement means based on all or part of the acquired first ocular refraction, the first anterior ocular shape information, and the second anterior ocular shape information; a process for determining the second ocular refraction of the test eye in an unaccommodative state; and a process for determining the amount of accommodative intervention when the ocular refraction of the test eye is measured by the ocular refraction measurement means; and an output step for outputting the processing results of the processing steps. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is an external view of an ophthalmic device. [Figure 2]FIG. 2 is a diagram illustrating an optical system arranged in an inspection unit. [Figure 3] FIG. 2 is a functional block diagram showing a control system of the ophthalmologic apparatus. [Figure 4] 10 is an example of a cross-sectional image of the anterior segment of the eye acquired by a cross-sectional photographing optical system. [Figure 5] 10A and 10B are diagrams illustrating a method for determining the axial length of the eye and the refractive power of the eye in a disaccommodated state by ray tracing. [Figure 6] FIG. 1 is a diagram illustrating an example of a growth curve of a child's lens. DETAILED DESCRIPTION OF THE INVENTION

[0008] [overview] Hereinafter, one exemplary embodiment will be described with reference to the drawings. Note that the items grouped in <> below can be used independently or in conjunction with each other.

[0009] The ophthalmic device (e.g., the ophthalmic device 1) includes a first anterior ocular segment information acquiring means (e.g., the control unit 50), an eye refractive power acquiring means (e.g., the control unit 50), a second anterior ocular segment information acquiring means (e.g., the control unit 50), and a processing means (e.g., the control unit 50). The ophthalmic device may further include an output means (e.g., the control unit 50).

[0010] The first anterior eye information acquiring means is configured to acquire first anterior eye shape information of the subject's eye in a non-accommodative state or a state equivalent to non-accommodation. The eye refractive power acquiring means is configured to acquire first eye refractive power measured by eye refractive power measuring means (e.g., eye refractive power testing unit 12A) that measures the eye refractive power of the subject's eye. The second anterior eye information acquiring means is configured to acquire second anterior eye shape information of the subject's eye when the first eye refractive power is measured by the eye refractive power measuring means.

[0011] For example, the processing means may be configured to perform at least one of the following processes: a first process for determining whether accommodation intervention is required when the eye refractive power of the subject's eye is measured by the eye refractive power measurement means, a second process for determining the second eye refractive power of the subject's eye in a non-accommodative state, and a third process for determining the amount of accommodation intervention required when the eye refractive power of the subject's eye is measured by the eye refractive power measurement means, based on all or part of the first eye refractive power acquired by the eye refractive power acquisition means, the first anterior eye segment shape information acquired by the first anterior eye segment information acquisition means, and the second anterior eye segment shape information acquired by the second anterior eye segment information acquisition means. This allows for more appropriate evaluation of the eye refractive power state of the subject's eye, which is likely to require accommodation intervention, by providing information that can more appropriately evaluate the measurement results of the eye refractive power of the subject's eye.

[0012] For example, the processing means may determine whether or not an accommodation intervention has occurred for the first eye refractive power acquired by the eye refractive power acquisition means based on a comparison between the first anterior eye segment shape information and the second anterior eye segment shape information. In this case, for example, the first anterior eye segment shape information and the second anterior eye segment shape information may include at least one common element of the anterior chamber depth, the radius of curvature of the front surface of the crystalline lens, the crystalline lens thickness, and the pupil diameter of the subject eye, and the processing means may determine that an accommodation intervention has occurred when the common element has changed by a predetermined value or more.

[0013] In addition, when the processing means has obtained the second eye refractive power of the test eye in an unaccommodated state, the processing means may determine whether or not accommodation intervention is required for the first eye refractive power based on a comparison between this second eye refractive power and the first eye refractive power.

[0014] For example, the processing means may be configured to calculate the axial length of the test eye based on the first ocular refractive power and the second anterior ocular shape information acquired by the ocular refractive power acquisition means, and to calculate the second ocular refractive power without accommodation based on the calculated axial length and the first anterior ocular shape information. By obtaining the ocular refractive power without accommodation, the measurement result of the ocular refractive power of the test eye can be more appropriately evaluated. Note that, if the ophthalmic apparatus separately includes axial length acquisition means for acquiring the axial length of the test eye, the processing means may be configured to calculate the second ocular refractive power without accommodation based on the axial length acquired by the axial length acquisition means and the first anterior ocular shape information.

[0015] For example, the processing means may be configured to determine the amount of accommodation intervention for the first eye refractive power by comparing the first eye refractive power acquired by the eye refractive power acquisition means with the second eye refractive power in a non-accommodative state. This allows for more appropriate evaluation of the measurement results of the eye refractive power of the subject eye. Furthermore, when a determination result on the presence or absence of accommodation intervention is obtained, it becomes possible to more appropriately determine whether the measured first eye refractive power is appropriate.

[0016] The ophthalmic apparatus may include an ocular refraction measuring means (e.g., an ocular refraction testing unit 12A) configured to acquire a first ocular refraction. In this case, the ocular refraction acquiring means may include an ocular refraction measuring optical system (e.g., an ocular refraction measuring optical system 100) that measures the ocular refraction of the subject's eye by projecting measurement light onto the fundus of the subject's eye and receiving reflected light of the measurement light from the fundus. The ophthalmic apparatus may also include an anterior ocular segment imaging means (e.g., an anterior ocular segment imaging unit 12B) configured to acquire first anterior ocular segment shape information. In this case, the anterior ocular segment imaging means may include an anterior ocular segment imaging optical system (e.g., a cross-sectional imaging optical system 300) that projects imaging light onto the anterior ocular segment of the subject's eye and receives return light from the anterior ocular segment of the subject's eye that is optically cut by the imaging light, thereby capturing a cross-sectional image of the anterior ocular segment of the subject's eye. The anterior ocular segment imaging means may also be configured to acquire second anterior ocular segment shape information.

[0017] The first anterior eye segment shape information in the non-accommodative state may be actual anterior eye segment information of the subject's eye under accommodative paralysis. Alternatively, the first anterior eye segment shape information in the non-accommodative state may be obtained from literature values. In the case of anterior eye segment shape information obtained from literature values, the information is taken to be information in a state corresponding to the non-accommodative state of the subject's eye.

[0018] It should be noted that the present disclosure is not limited to the devices described in the present embodiment. For example, an ophthalmic processing program (software) that performs the functions of the following embodiments may be supplied to a system or device via a network or various storage media. Then, a control device (e.g., a CPU) of the system or device may read and execute the program.

[0019] In this embodiment, at least one of the first anterior eye segment information acquiring means, the eye refractive power acquiring means, the second anterior eye segment information acquiring means, the processing means, and the output means may be combined. Alternatively, for example, the first anterior eye segment information acquiring means, the eye refractive power acquiring means, the second anterior eye segment information acquiring means, the processing means, and the output means may each be provided separately.

[0020] [Example] An example of this embodiment will be described with reference to the drawings. FIG. 1 is an external view of an ophthalmic apparatus 1. The ophthalmic apparatus 1 of the present disclosure includes at least a base 11, an examination unit 12, an alignment drive unit 13, a face support unit 15, a monitor 16, an operation unit 17, and a control unit 50. The examination unit 12 houses an optical system and the like used for examinations such as measurement and photography of the subject's eye (E). In this example, a multifunction device will be described as an example in which the examination unit 12 is equipped with an eye refractive power examination unit 12A and an anterior eye photography unit 12B.

[0021] The face support unit 15 is fixed to the base 11 and supports the examiner's face to fix the subject's eye. The alignment drive unit 13 changes the positional relationship of the examination unit 12 with respect to the subject's eye. For example, the alignment drive unit 13 moves the examination unit 12 three-dimensionally with respect to the base 11, thereby moving the examination unit 12 in the X direction (left-right direction), Y direction (up-down direction), and Z direction (front-back direction) with respect to the subject's eye.

[0022] The monitor 16 displays various information (for example, an anterior ocular segment image of the subject's eye, the optical characteristics of the subject's eye, the imaging test results, etc.). The operation unit 17 is used to perform various settings. The monitor 16 may function as a touch panel and may also serve as the operation unit 17.

[0023] <Optical system> 2 is a diagram illustrating the optical systems arranged in the examination unit 12. The optical systems of the examination unit 12 include an eye refractive power measuring optical system 100 provided in the eye refractive power examination unit 12A, a fixation target presenting optical system 150, a front observation optical system 200, and a cross-section photographing optical system 300 provided in the anterior eye photographing unit 12B. The optical systems of the examination unit 12 also include an alignment target projecting optical system 400.

[0024] <Ocular refractive power measurement optical system> The eye refractive power measurement optical system 100 is configured to objectively measure the eye refractive power of a subject's eye. The eye refractive power measurement optical system 100 has a projection optical system 100a and a light receiving optical system 100b. The projection optical system 100a projects a spot-shaped measurement light onto the fundus of the subject's eye through the center of the pupil of the subject's eye. The projection optical system 100a includes a measurement light source 111, a relay lens 112, a hole mirror 113, a prism 115, a relay lens 116, an objective lens 117, etc.

[0025] The measurement light source 111 emits a measurement light beam. The measurement light source 111 may be an SLD light source, an LED light source, or any other light source. The light source 111 is conjugate with the fundus of the subject's eye. The hole portion of the hole mirror 113 is conjugate with the pupil of the subject's eye. The prism 115 is a light beam deflecting member. The prism 115 is disposed at a position that is not conjugate with the pupil of the subject's eye, and decenters the measurement light beam passing through the prism 115 with respect to the optical axis L1. The prism 115 is rotated around the optical axis L1 by a drive unit (not shown).

[0026] The light-receiving optical system 100b extracts a light beam reflected by the fundus of the subject's eye in a ring shape through the pupil periphery of the subject's eye. For example, the light-receiving optical system 100b shares components from the objective lens 117 to the hole mirror 113 of the projection optical system 100a. The light-receiving optical system 100b includes a relay lens 120, a mirror 121, a light-receiving diaphragm 122, a collimator lens 123, a ring lens 124, an image sensor 125, etc. The ring lens 124 is optically conjugate with the pupil of the subject's eye. The light-receiving diaphragm 122, the image sensor 125, and the fundus of the subject's eye are also conjugate with each other.

[0027] The measurement light beam emitted from the measurement light source 111 passes through optical components in order from a relay lens 112, a hole mirror 113, a prism 115, a lens 116, and an objective lens 117, and forms a spot-shaped point light source image on the fundus of the subject's eye. At this time, the pupil projection image of the hole part in the hole mirror 113 (projected light beam on the pupil) is rotated eccentrically at high speed by the prism 115 that rotates around the optical axis.

[0028] The returning light (reflected and scattered light) from the fundus passes through the objective lens 117, lens 116, prism 115, hole mirror 113, relay lens 120, and mirror 121 and is again focused on the light receiving aperture 122, where it is focused as a ring-shaped image on the image sensor 125 by the collimator lens 123 and ring lens 124.

[0029] The measurement light source 111 and relay lens 112 included in the projection optical system 100a, and the light-receiving diaphragm 122, collimator lens 123, ring lens 124, and image sensor 125 included in the light-receiving optical system 100b are movable together in the optical axis direction as a drive unit 130. These are synchronously moved together by a drive mechanism 155a that moves a fixation target 155 of the fixation target presenting optical system 150. By moving the drive unit 130 in the optical axis direction, the measurement light source 111, the light-receiving diaphragm 122, and the image sensor 125 are positioned so as to be optically conjugate with the fundus of the subject's eye. Then, the ring image formed on the image sensor 125 via the ring lens 124 is analyzed to derive the ocular refractive power. For example, the values ​​of the spherical power (SPH), the astigmatic power (CYL), and the astigmatic axis angle (AXIS) can be calculated as the ocular refractive power.

[0030] The eye refractive power measuring optical system 100, which is an example of an objective eye refractive power measurement system, is not limited to the above configuration as long as it can obtain eye refractive power. For example, it may be configured with a Shack-Hartmann sensor. For details, see, for example, Japanese Patent Application Laid-Open No. 2018-47049.

[0031] <Fixation target presentation optical system> The fixation target presenting optical system 150 is configured to present a fixation target to the subject's eye. The fixation target presenting optical system 150 is used to fixate the subject's eye. The fixation target presenting optical system 150 is also used to apply fogging and accommodative load to the subject's eye. For example, the fixation target presenting optical system 150 includes a light source 151, a fixation target plate 155, a projection lens 156, a dichroic mirror 503, a dichroic mirror 501, an objective lens 117, and the like. The fixation target plate 155 is movable along the optical axis by a drive unit 155a. An index light beam from the fixation target plate 155 illuminated by the light source 151 is projected onto the subject's eye via the projection lens 156, the dichroic mirror 503, the dichroic mirror 502, the dichroic mirror 501, and the objective lens 117.

[0032] <Front observation optical system> The front observation optical system 200 is configured to capture a front image of the anterior segment of the subject's eye. The front observation optical system 200 includes an objective lens 117, a dichroic mirror 501, a dichroic mirror 502, a photographing lens 204, an image sensor 205, etc. A front image of the subject's eye is captured by the objective lens 117 to the image sensor 205. An observation image of the anterior segment may be acquired as the front image. The observation image is used for alignment, etc. In addition, an index image (pattern index image) based on a pattern index projected onto the cornea of ​​the subject's eye from the index projection optical system 400 is captured by the front observation optical system 200.

[0033] <Cross-section imaging optical system> The cross-section imaging optical system 300 is configured to capture a cross-sectional image of the anterior segment of the eye. The cross-section imaging optical system 300 includes a light projecting optical system 300a and a light receiving optical system 300b. The light projecting optical system 300a is coaxial with the optical axis L1 of the measurement optical system 100 and projects a slit of imaging light onto the anterior segment of the eye. The illumination optical system 300a includes a light source 311, a lens 312, a slit 312, an objective lens 117 shared with the measurement optical system 100, and the like. In this embodiment, the slit of imaging light is visible light. For example, a visible light source emitting blue light may be used as the light source 311.

[0034] Slit light (photography light) from slit 312 illuminated by light source 311 is projected onto the anterior segment of the subject's eye via dichroic mirror 503, dichroic mirror 502, dichroic mirror 501, and objective lens 117, and the anterior segment of the subject's eye is optically cut by the slit light (photography light).

[0035] The light receiving optical system 300b includes a lens system 322 and an image sensor 321, which is an example of a photodetector. The optical axis LB1 of the light receiving optical system 300b is tilted relative to the optical axis L1. In the light receiving optical system 300b, the lens system 322 and the image sensor 321 are disposed in a Scheimpflug relationship with a cut surface set in the anterior segment. That is, the optical arrangement is such that the extensions of the cut surface, the principal plane of the lens system 322, and the imaging surface of the image sensor 321 intersect at a single intersection (single axis). The image sensor 321 receives return light (reflected light or scattered light) from the anterior segment, which has been optically cut by the slit light. Then, a cross-sectional image of the anterior segment is acquired based on a signal from the image sensor 321.

[0036] <Alignment target projection optical system> The alignment target projection optical system 400 is configured to align (position) the examination unit 12 (an optical system including the eye refractive power measurement optical system 100 and the cross-section photographing optical system 300) with respect to the subject's eye. The alignment target projection optical system 400 projects an alignment target onto the cornea of ​​the subject's eye. The alignment target projection optical system 400 has an alignment light source 401 and a light source 411, which are arranged symmetrically with respect to the optical axis L1. The light source 401 projects diffused light onto the cornea of ​​the subject's eye, and the light source 411 projects parallel light onto the cornea of ​​the subject's eye via a collimator lens (not shown). The examination unit 12 is moved in the front-to-back direction (Z direction) so that a corneal Purkinje image formed by parallel light and a Purkinje image formed by diffused light are captured at a predetermined ratio, thereby adjusting the alignment state in the working distance direction (Z direction). Furthermore, by detecting the centers of the two light sources 401, the alignment state of the inspection unit 12 in the left-right and up-down directions (XY directions) is adjusted.

[0037] <Control system> FIG. 3 is a functional block diagram showing the control system of the ophthalmic apparatus 1. In this embodiment, the control unit 50 controls the entire ophthalmic apparatus 1. The control unit 50 also functions as a processing unit. The control unit 50 is connected to the eye refractive power examination unit 12A and the anterior eye imaging unit 12B. The control unit 50 functions as an acquisition unit that acquires the eye refractive power measured by the eye refractive power examination unit 12A, which functions as an eye refractive power measurement unit. The control unit 50 also functions as a unit that acquires the shape of the anterior eye of the subject's eye by processing an anterior eye image captured by the anterior eye imaging unit 12B, which functions as a cross-sectional imaging unit.

[0038] The control unit 50 is also connected to electrical elements such as a memory 52, which is an example of a storage means, the alignment driving unit 13, the monitor 16, and the operation unit 17. In this case, the control unit 50 also functions to acquire information (for example, anterior eye shape information corresponding to the non-accommodative state of the subject's eye) stored in the memory 52. ​​The control unit 50 also functions as an output means for outputting the processing results.

[0039] <Operation> The operation of the ophthalmologic apparatus 1 having the above-described configuration will be described below. Here, the case where an eye refractive power examination is performed periodically (for example, every three months) for the purpose of managing the progression of refractive error of the subject's eye (for example, managing the progression of myopia) will be described as an example.

[0040] At the first examination of the subject's eye, a test is performed to obtain information on the shape of the anterior segment of the eye in a non-accommodative state. In this case, a cycloplegic agent is instilled into the subject's eye prior to the test.

[0041] When the face of the subject is supported by the face support unit 15, an image of the anterior eye segment of the subject's eye illuminated by an anterior eye illumination light source (not shown) is captured by the image sensor 205 of the front observation optical system 200, and the anterior eye segment image is displayed on the monitor 16. In addition, an index image projected onto the cornea of ​​the subject's eye by the alignment index projection optical system 400 is captured by the image sensor 205. In addition, the subject's eye is made to fixate on a fixation target presented by the fixation target presenting optical system 150.

[0042] The control unit 50 processes the front image of the anterior eye acquired by the anterior eye observation optical system 200, and detects the alignment state of the inspection unit 12 in the X, Y, and Z directions with respect to the subject's eye based on the target image (corneal reflection bright spot) projected onto the cornea of ​​the subject's eye by the alignment target projection optical system 400. Then, the control unit 50 controls the driving of the alignment drive unit 13 to move the inspection unit 12 in the X, Y, and Z directions so that the alignment states in the X, Y, and Z directions fall within predetermined tolerance ranges, respectively.

[0043] When the alignment of the examination unit 12 with respect to the subject's eye is completed, the light source 311 of the light projecting optical system 300a of the cross-section photographing optical system 300 is turned on, and a slit light is projected onto the anterior segment of the subject's eye in order to acquire anterior segment shape information. Return light (reflected light or scattered light) from the anterior segment, optically cut by the slit light, is received by the image sensor 321 of the light receiving optical system 300b, and a cross-sectional image of the anterior segment is acquired. The acquired cross-sectional image is stored in the memory 52.

[0044] 4 shows an example of a cross-sectional image of the anterior eye segment acquired by the cross-sectional imaging optical system 300. The control unit 50 performs image processing on the acquired cross-sectional image to obtain various values ​​as anterior eye segment shape information, such as the radius of curvature of the anterior cornea KF, the radius of curvature of the posterior cornea KR, the corneal thickness KT, the anterior chamber depth ACD, the radius of curvature of the anterior lens LF, the radius of curvature of the posterior lens LR, the lens thickness LT, and the pupil diameter PD. The acquired anterior eye segment shape information is stored in the memory 52 as anterior eye segment shape information of the subject's eye in a disaccommodated state. A cross-sectional image of the subject's eye in a disaccommodated state may also be stored in the memory 52 at the same time.

[0045] Furthermore, since the ophthalmologic apparatus 1 of this embodiment is a multifunction device equipped with the eye refraction examination unit 12A and the anterior eye imaging unit 12B, eye refraction measurement is performed by the eye refraction measurement optical system 100 in an aligned state simultaneously with, immediately before, or before or after capturing a cross-sectional image of the anterior eye. In the measurement by the eye refraction measurement optical system 100, a preliminary measurement is first performed, and based on the spherical power result of the preliminary measurement, the fixation target plate 155 is moved in the optical axis direction so as to add a cloud to the subject's eye. The projection optical system 100a projects measurement light onto the fundus of the subject's eye, and the reflected light of the measurement light from the fundus is received by the image sensor 125 via the ring lens 124, thereby acquiring a ring image that changes depending on the eye refraction of the subject's eye. The control unit 50 analyzes the acquired ring image and obtains measurement results of the eye refraction (spherical power, astigmatism power, astigmatism axis angle, etc.). The measurement results are displayed on the monitor 16 and stored in the memory 52.

[0046] Next, a case will be described in which the refractive power of the subject's eye is measured at the second or subsequent examination in a periodic medical checkup (for example, every three months) for managing the progress of the refractive power of the subject's eye. In this case, unlike the first examination, no cycloplegic agent is instilled and the measurement (examination) is performed in a non-cycloplegic state (a state without cycloplegia).

[0047] As described above, the examination unit 12 is aligned with the subject's eye based on the target image projected onto the cornea of ​​the subject's eye by the alignment target projection optical system 400. Once alignment is complete, measurement is performed using the eye refractive power measurement optical system 100. In eye refractive power measurement, a preliminary measurement is first performed, and then the main measurement is performed with the subject's eye fogging based on the results of the preliminary measurement. The measurement results of the eye refractive power obtained in the main measurement are stored in the memory 52.

[0048] Simultaneously with the eye refractive power measurement by the eye refractive power measurement optical system 100 (which may be immediately before or immediately after the eye refractive power measurement), a cross-sectional image of the anterior eye segment is captured by the cross-sectional imaging optical system 300. The control unit 50 processes the captured cross-sectional image to obtain anterior eye segment shape information. This anterior eye segment shape information is obtained as anterior eye segment shape information of the subject's eye when the eye refractive power is measured by the eye refractive power measurement optical system 100.

[0049] When anterior eye shape information is acquired during eye refractive power measurement, an evaluation of the eye refractive power obtained during eye refractive power measurement without accommodative paralysis is performed based on this information and the anterior eye shape information in the non-accommodative state obtained during the first examination. Note that, hereinafter, the anterior eye shape information in the non-accommodative state is referred to as first anterior eye shape information, and the anterior eye shape information obtained during the second and subsequent examinations without accommodative paralysis (a state without accommodative paralysis) is referred to as second anterior eye shape information.

[0050] For example, the control unit 50 compares the first anterior segment shape information with the second anterior segment shape information to determine or evaluate the state of accommodation intervention of the test eye when measuring the eye refractive power without accommodative paralysis. In objective eye refractive power measurement, if the test eye is not sufficiently fogging, the measurement may be performed in a state of accommodation intervention (a state in which accommodation is intervened). In particular, pediatric eyes and hyperopic eyes are likely to be measured in a state of accommodation intervention. Therefore, in order to appropriately manage the progression of the eye refractive power of the test eye, it is preferable to determine (or evaluate) the state of accommodation intervention for the eye refractive power measured without accommodative paralysis.

[0051] <Process for determining whether or not accommodation intervention is required when measuring eye refraction> An example of a process for determining (or evaluating) the state of accommodative intervention for ocular refractive power measured without cycloplegia will be described. With regard to the corneal anterior surface curvature radius KF, corneal posterior surface curvature radius KR, anterior chamber depth ACD, anterior lens radius of curvature LF, posterior lens radius of curvature LR, lens thickness LT, and pupil diameter PD shown in Figure 4, if accommodative intervention occurs during ocular refractive power measurement without cycloplegia, the anterior chamber depth ACD, anterior lens radius of curvature LF, lens thickness LT, and pupil diameter PD are likely to change compared to the first anterior segment shape information in the non-accommodative state. Therefore, the first anterior segment shape information and the second anterior segment shape information include at least one common element. The common element is compared between the first anterior segment shape information and the second anterior segment shape information. If the comparison result shows a change of more than a predetermined value, it is determined that accommodative intervention occurred in the subject's eye during ocular refractive power measurement without cycloplegia. The determination of whether or not accommodative intervention is required may be made by comprehensively processing changes in the anterior chamber depth ACD, the anterior lens radius of curvature LF, the lens thickness LT, and the pupil diameter PD. The determination result of whether or not accommodative intervention is required is output to and displayed on the monitor 16. This prevents the examiner from erroneously determining that myopia is progressing, for example, by looking only at the measurement results of ocular refractive power. It is also possible to provide information for appropriately diagnosing the ocular refractive power state of the examinee's eye.

[0052] If it is determined that there has been an accommodation intervention in the subject's eye, then remeasurement may be performed after taking measures such as relaxing the subject so that the subject's eye is sufficiently fogging up when the eye refraction is measured by the eye refraction measurement optical system 100. If it is also determined that there has been an accommodation intervention in the subject's eye in this remeasurement, then an accommodative paralytic agent may be instilled into the eye, and then the eye refraction may be measured by the eye refraction measurement optical system 100.

[0053] <Process for determining eye refractive power without accommodation> Furthermore, once the ocular refractive power and the second anterior ocular segment shape information under non-accommodative conditions are obtained, a process for determining (determining) the ocular refractive power of the subject's eye in the non-accommodative state may be performed based on these and the first anterior ocular segment shape information. The process for determining the ocular refractive power of the subject's eye in the non-accommodative state will be described below.

[0054] First, the control unit 50 calculates the axial length of the subject's eye based on the ocular refractive power under non-accommodative conditions and the second anterior eye shape information. In this embodiment, the axial length is derived based on ray tracing calculations on the light section plane formed by the slit light of the cross-sectional imaging optical system 300. Figure 5 is a diagram illustrating a method for calculating the axial length and the ocular refractive power under non-accommodative conditions by ray tracing.

[0055] 5, the far point when the eye refractive power without accommodative paralysis (hereinafter referred to as the first eye refractive power SP1) is obtained is designated as FP1. A ray Lx1 incident on the subject's eye from this far point FP1 is traced, and the ray Lx1 is refracted by each optic body of the subject's eye and intersects with the eye's optical axis (which may be the visual axis) Le to find the intersection point AP, thereby deriving the axial length AL (the distance between the corneal vertex Ct and the intersection point AP).

[0056] First, based on the measurement results of the eye refractive power, the distance BL1 of the far point FP1 of the test eye relative to the corneal vertex Ct is calculated using the formula "VD + 1000 / (-SP1)." For example, if the first eye refractive power SP1 has no astigmatism, SPH = -5D, and VD = 12 mm, the distance BL1 is 12 + 1000 / 5 = 212 mm. It is assumed that a ray Lx1 from the far point FP1 at this distance BL1 forms an image on the fundus of the test eye. Note that VD = 12 mm is a fixed value indicating the corneal vertex distance assuming the wearer of spectacle lenses. Furthermore, if the test eye has astigmatism power (CYL), the distance BL1 on the light section (horizontal direction in this embodiment) is calculated taking into account the astigmatism power (CYL) and the astigmatism axis angle (AXIS).

[0057] The axial length AL is determined by tracing a ray Lx1 from a far point FP1. For example, when tracing the ray, consider a ray Lx1 that is incident on the pupil of the subject's eye (a position approximately 3 mm behind the cornea) at a pupil diameter of 6 mm.

[0058] Light ray Lx1 incident at the pupil diameter position of 6 mm is refracted as it passes through each optic body of the eye tissue (cornea, aqueous humor, and lens). Light ray Lx1 is first refracted at the anterior surface of the cornea. The intersection point of light ray Lx1 with the anterior surface of the cornea is calculated based on the radius of curvature KF of the anterior cornea, the position of the far point FP1, and the ray angle at the far point FP1. Furthermore, the angle of incidence of light ray Lx1 at this intersection point is calculated. After reaching the anterior surface of the cornea, light ray Lx1 changes direction at a refraction angle determined with respect to the angle of incidence based on Snell's law. In this way, light ray Lx1 is sequentially tracked at the boundary surface of each optic body. In this case, the second anterior segment shape information obtained under non-cycloplegic conditions (corneal anterior surface curvature radius KF, corneal posterior surface curvature radius KR, corneal thickness KT, anterior chamber depth ACD, lens anterior surface curvature radius LF, lens posterior surface curvature radius LR, and lens thickness LT shown in FIG. 4) is used as appropriate to determine the intersection point between each boundary surface and the light ray Lx1. In addition, the refractive index of each optic body of the eye tissue is given in advance. In this embodiment, the intersection point AP where the light ray Lx1 intersects with the optical axis Le of the eye after leaving the lens posterior surface is finally determined. This allows the axial length AL, which is the distance from the intersection point AP to the corneal vertex Ct, to be determined.

[0059] It is known that the refractive index of the crystalline lens changes with age. Therefore, the ophthalmic apparatus 1 may have a calculation formula or a look-up table in which the refractive index of the crystalline lens is associated with each age. In this case, the age is input, and the refractive index according to the age is acquired. The refractive index may be used to perform ray tracing calculations.

[0060] Details of how to determine the axial length AL by ray tracing as described above are disclosed in Japanese Patent Application Laid-Open No. 2021-154066, so this technique can be used.

[0061] Once the axial length AL of the test eye has been determined, the eye refractive power in the non-accommodative state (hereinafter referred to as the second eye refractive power SP2) is determined based on this axial length AL and the first anterior eye shape information (anterior eye shape information in the non-accommodative state) previously acquired.

[0062] The second eye's refractive power SP2 can be calculated by the reverse ray tracing used to calculate the axial length AL. Since the axial length AL is now known, the ray Lx2 originating from the intersection point AP on the fundus of the test eye passes through the optic body of the eye (cornea, aqueous humor, and lens) in the unaccommodated state, emerges from the anterior cornea, and intersects with the eye's optical axis Le. This point is defined as the far point FP2 of the unaccommodated eye. That is, the ray Lx1 originating from the intersection point AP is first refracted at the posterior surface of the lens. The intersection point of the ray Lx1 and the posterior surface of the lens is calculated from the posterior surface of the lens and the position of the ray guided toward the pupil diameter position of 6 mm at the same pupil position as described above. The angle of incidence on the posterior surface of the lens at this time is also determined. The direction of the ray Lx2 that reaches the lens is changed by a predetermined refraction angle based on Snell's law. By tracing the ray successively on each transparent surface, the position of the far point FP2, where the ray Lx2 emerging from the front surface of the cornea intersects with the optical axis Le of the eye, can be determined.

[0063] Once the position of the far point FP2 is determined, the refractive power SP2 of the second eye in an unaccommodated state can be determined by performing the reverse calculation of the calculation used to determine the far point FP1 described above. That is, if the distance of the far point FP2 from the corneal vertex Ct is BL2, the refractive power SP2 of the second eye can be determined by solving the equation "BL2 = VD + 1000 / (-SP2)." The determined refractive power SP2 of the second eye is output by the control unit 50 to the monitor 16, and the result of the refractive power SP2 of the second eye is displayed on the monitor 16.

[0064] Here, if the ocular refractive power measured under non-accommodative conditions is determined to have undergone accommodative intervention, the second ocular refractive power SP2 in the non-accommodative state can be obtained as described above, thereby providing information that allows for a more appropriate diagnosis of the ocular refractive power state of the subject's eye. Furthermore, since the second ocular refractive power SP2 in the non-accommodative state can be obtained without instilling an accommodative paralytic agent, the burden on the subject is reduced. Furthermore, by obtaining the second ocular refractive power SP2 in the non-accommodative state, the measurement results of the ocular refractive power of the subject's eye can be more appropriately evaluated in terms of managing the progression of the ocular refractive power of the subject's eye.

[0065] <Process for determining the amount of accommodation intervention during eye refractive power measurement> Furthermore, once the second eye refractive power SP2 in the non-accommodative state is obtained as described above, the amount of accommodative intervention during measurement of the eye refractive power of the test eye without accommodative paralysis may be determined based on this second eye refractive power SP2 and the first eye refractive power SP1 obtained in measurement without accommodative paralysis. For example, the amount of accommodative intervention is obtained by comparing the second eye refractive power SP2 with the first eye refractive power SP1. The obtained amount of accommodative intervention is output to the monitor 16 by the control unit 50, and the result of the second eye refractive power SP2 is displayed on the monitor 16. Obtaining the amount of accommodative intervention also provides information that allows for more appropriate diagnosis of the eye refractive power state of the test eye, which is likely to require accommodative intervention. Furthermore, the measurement results of the eye refractive power of the test eye can be more appropriately evaluated.

[0066] In the above, in this embodiment, the process of determining whether or not accommodative intervention is required when measuring eye refractive power, the process of calculating eye refractive power in a non-accommodative state, and the process of calculating the amount of accommodative intervention when measuring eye refractive power have been described, but it is not necessary for all of these processes to be performed, and at least one of these processes may be performed.

[0067] <Example of transformation> Although typical embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and various modifications are possible.

[0068] For example, in the above embodiment, the presence or absence of accommodative intervention during eye refractive power measurement is determined based on the first anterior eye shape information in the non-accommodative state and the eye refractive power and second anterior eye shape information in the non-accommodative state, but this is not limited to this. When the second eye refractive power SP2 of the test eye in the non-accommodative state is obtained, the second eye refractive power SP2 and the first eye refractive power SP1 in the non-accommodative state may be compared to determine the presence or absence of accommodative intervention for the first eye refractive power SP1.

[0069] In the above embodiment, anterior eye shape information in a state of no accommodation of the subject's eye is obtained based on a cross-sectional image of the anterior eye captured by the cross-sectional imaging optical system 300 after a cycloplegic agent is instilled into the subject's eye, but this is not limited to this. For example, the anterior eye shape information in a state of no accommodation may be obtained from literature values. The anterior eye shape information obtained from literature values ​​is used as information in a state corresponding to no accommodation of the subject's eye. In this case, the anterior eye shape information may be obtained by taking into account the age, sex, race, etc. of the subject.

[0070] Furthermore, the anterior segment shape information in the non-accommodative state may be corrected by applying a growth curve obtained from literature values ​​or the like to the anterior segment shape information obtained under accommodative paralysis, and taking into account changes due to growth of the subject's eye at the time of eye refractive power measurement in the subsequent progress management of eye refractive power. For example, FIG. 6 illustrates an example of a growth curve for a child's lens. In FIG. 6(a), left panel A shows the change in the radius of curvature of the anterior surface of the lens with age, and right panel B shows the rate of change. In FIG. 6(b), left panel A shows the change in the radius of curvature of the posterior surface of the lens with age, and right panel B shows the rate of change. As shown in FIG. 6, in children, the radius of curvature of both the anterior and posterior surfaces of the lens tends to change significantly as they grow. Therefore, when the subject's age (years and months) at the time of eye refractive power measurement in the subsequent eye refractive power progress management is input for the anterior eye lens radius of curvature LF and the posterior eye lens radius of curvature LR (see Figure 4) of the anterior eye segment shape information obtained under initial accommodative paralysis, the anterior eye lens radius of curvature LF and the posterior eye lens radius of curvature LR are corrected based on the correction formula based on the growth curve in Figure 6. The corrected anterior eye segment shape is acquired as anterior eye segment shape information in a non-accommodative state at the time of eye refractive power measurement. Anterior eye segment shape information other than the lens may also be corrected in a similar manner, taking into account changes due to growth.

[0071] Furthermore, the change in the lens curvature radius due to growth is sufficiently smaller than the change due to accommodative intervention, and the direction of the change is also opposite in children who are more susceptible to accommodative intervention. Therefore, in the process of determining whether or not accommodative intervention was performed during the above-mentioned eye refractive power measurement, any change that deviates significantly from the growth curve may be determined to be due to accommodative intervention.

[0072] In the above description, the axial length AL calculated by ray tracing based on the ocular refractive power without accommodation and the second anterior segment shape information is used in the process of calculating the ocular refractive power without accommodation. However, this is not limited to this. The axial length AL may be actually measured by a separate optical axial length measurement device (such as the device disclosed in Japanese Patent Application Laid-Open No. 2008-188047) or an OCT (optical coherence tomography) device. In this case, since the axial length AL is actually measured, as opposed to the axial length AL calculated by ray tracing, a more accurate ocular refractive power without accommodation can be obtained.

[0073] In the above embodiment, the description has been given taking as an example a multifunction device equipped with an eye refraction measuring means (eye refraction examination unit 12A) and an anterior eye segment photographing means (anterior eye segment photographing unit 12B), but the ophthalmic apparatus equipped with the eye refraction measuring means and the ophthalmic apparatus equipped with the anterior eye segment photographing means may be separate entities. In the above embodiment, the control unit 50 functioning as a processing means is shared with the control unit of the ophthalmic apparatus 1 equipped with the eye refraction measuring means (eye refraction examination unit 12A) and anterior eye segment photographing means (anterior eye segment photographing unit 12B), but it may be configured as a separate entity (for example, a personal computer) that receives and processes the first anterior eye segment shape information, the first eye refraction, and the second anterior eye segment shape information output from the eye refraction measuring means (eye refraction examination unit 12A) and the anterior eye segment photographing means (anterior eye segment photographing unit 12B). In this case, the first anterior eye segment shape information, the first eye refractive power, and the second anterior eye segment shape information may be output via network communication such as the Internet, and thus may be acquired by the ophthalmologic apparatus (controller). [Explanation of symbols]

[0074] 1 Ophthalmology equipment 12 Inspection Department 12A Eye Refractive Examination Department 12B Anterior segment imaging department 50 control section 52 memory 100 Eye refractive power measurement optical system 300 Cross-sectional imaging optical system

Claims

1. a first anterior segment information acquiring means for acquiring first anterior segment shape information of the subject's eye in a non-accommodative state or a state equivalent to non-accommodative state; an eye refractive power acquiring means for acquiring a first eye refractive power measured by an eye refractive power measuring means for measuring the eye refractive power of the subject's eye; a second anterior ocular segment information acquiring means for acquiring second anterior ocular segment shape information of the subject's eye when the first ocular refractive power is measured by the ocular refractive power measuring means; a processing means for performing at least one of the following processes based on all or part of the acquired first eye refractive power, the first anterior eye segment shape information, and the second anterior eye segment shape information: a process for determining whether or not accommodation intervention is required when the eye refractive power of the subject's eye is measured by the eye refractive power measurement means; a process for determining the second eye refractive power of the subject's eye in a non-accommodative state; and a process for determining the amount of accommodation intervention when the eye refractive power of the subject's eye is measured by the eye refractive power measurement means; output means for outputting the processing result of said processing means; An ophthalmic apparatus comprising:

2. The ophthalmic apparatus of claim 1, The ophthalmic device is characterized in that the processing means determines whether or not accommodative intervention is required for the first eye refractive power based on a comparison between the first anterior eye shape information and the second anterior eye shape information, or determines whether or not accommodative intervention is required for the first eye refractive power based on a comparison between the first eye refractive power and the second eye refractive power.

3. The ophthalmic apparatus according to claim 1 or 2, The processing means calculates the axial length of the subject's eye based on the first eye refractive power acquired by the eye refractive power acquisition means and the second anterior eye shape information, and calculates the second eye refractive power in a non-accommodative state based on the calculated axial length and the first anterior eye shape information.

4. The ophthalmic apparatus according to any one of claims 1 to 3, The ophthalmologic apparatus according to claim 1, wherein the processing means compares the first eye refractive power with the second eye refractive power to determine an amount of accommodation intervention for the first eye refractive power.

5. The ophthalmic apparatus according to claim 2, the first anterior eye segment shape information and the second anterior eye segment shape information include at least one common element of an anterior chamber depth of the subject's eye, a radius of curvature of the anterior surface of a lens, a lens thickness, and a pupil diameter; The ophthalmologic apparatus is characterized in that the processing means determines that an accommodation intervention occurred when the first eye refractive power was measured if the common element has changed by a predetermined value or more.

6. The ophthalmic apparatus according to any one of claims 1 to 5, the eye refractive power measuring means configured to obtain the first eye refractive power; an anterior eye segment photographing means configured to acquire the first anterior eye segment shape information, the eye refractive power acquisition means includes an eye refractive power measurement optical system that projects measurement light onto a fundus of the eye to be examined and receives reflected light of the measurement light from the fundus, thereby measuring the eye refractive power of the eye to be examined; The anterior segment photographing means includes an anterior segment photographing optical system that projects photographing light onto the anterior segment of the subject's eye and receives return light from the anterior segment of the subject's eye that has been optically cut by the photographing light, thereby photographing a cross-sectional image of the anterior segment of the subject's eye.

7. An ophthalmic processing program executed by a control unit of an ophthalmic apparatus for obtaining an ocular refractive power of a subject's eye, a first anterior segment information acquiring step of acquiring first anterior segment shape information of the subject's eye in a non-accommodative state or a state equivalent to non-accommodative state; an eye refractive power acquiring step of acquiring a first eye refractive power measured by an eye refractive power measuring means that measures the eye refractive power of the subject's eye; a second anterior ocular segment information acquiring step of acquiring second anterior ocular segment shape information of the subject's eye when the first ocular refractive power is measured by the ocular refractive power measuring means; a processing step of performing at least one of a process of determining whether or not accommodation intervention is required when the eye refractive power of the subject's eye is measured by the eye refractive power measurement means, a process of determining the second eye refractive power of the subject's eye in a non-accommodative state, and a process of determining the amount of accommodation intervention when the eye refractive power of the subject's eye is measured by the eye refractive power measurement means, based on all or part of the acquired first eye refractive power, the first anterior eye segment shape information, and the second anterior eye segment shape information; an output step for outputting a processing result of the processing step; An ophthalmic processing program causing an ophthalmic apparatus to execute the above.

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