JP2018186930A - Ophthalmic imaging equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ophthalmologic photographing apparatus capable of efficiently photographing a fundus of a subject eye and obtaining a good tomographic image. An ophthalmic imaging apparatus that has an OCT optical system that detects an OCT signal based on measurement light and reference light irradiated on a subject's eye and that acquires OCT image data of the subject's eye by processing the OCT signal. An acquisition means for acquiring the anterior segment cross-sectional image data of the eye to be examined, a scan position setting means for setting the scan position of the measurement light based on the anterior segment cross-sectional image data acquired by the acquisition means, and an OCT optical system And control means for acquiring fundus OCT image data of the eye to be examined at the scanning position set by the scanning position setting means. [Selection] Figure 1

Description

  The present disclosure relates to an ophthalmologic photographing apparatus that photographs a tomographic image of an eye to be examined.

  As an ophthalmologic photographing apparatus for photographing a tomographic image of an eye to be examined, an optical coherence tomography (OCT) using low coherent light is known (see Patent Document 1).

JP 2008-29467 A

  By the way, the subject's eye suffering from a disease such as cataract may have turbidity in its cornea or lens. For example, for such an eye to be examined, even if measurement light is incident on the fundus of the eye to be examined using the above-described apparatus, the measurement light is reflected by the turbid portion, and a tomographic image of the fundus cannot be photographed well. There was a thing.

  In view of the above prior art, it is an object of the present disclosure to provide an ophthalmologic photographing apparatus that can efficiently photograph the fundus of an eye to be examined and obtain a good tomographic image.

  In order to solve the above problems, the present disclosure is characterized by having the following configuration.

(1) An ophthalmologic imaging apparatus according to a first aspect of the present disclosure includes an OCT optical system that detects an OCT signal based on measurement light and reference light irradiated on an eye to be examined, and processes the OCT signal to thereby examine the eye to be examined. An ophthalmologic imaging apparatus for acquiring OCT image data of an anterior eye section image data of an eye to be examined, and the measurement based on the anterior eye section image data acquired by the acquisition means Scanning position setting means for setting a scanning position of light; and control means for controlling the OCT optical system and acquiring fundus OCT image data of the eye to be examined at the scanning position set by the scanning position setting means; It is characterized by providing.
(2) An ophthalmologic imaging apparatus according to the second aspect of the present disclosure includes an OCT optical system that detects an OCT signal based on measurement light and reference light irradiated on an eye to be examined, and processes the OCT signal to thereby detect an eye to be examined. An ophthalmic imaging program used in an ophthalmic imaging apparatus for acquiring the OCT image data of the ophthalmic imaging apparatus, wherein the acquisition step acquires the anterior ocular segment image data of the eye to be examined by being executed by a processor of the ophthalmic imaging apparatus; Based on the anterior segment cross-sectional image data acquired in the acquisition step, a scanning position setting step for setting the scanning position of the measurement light, the OCT optical system is controlled, and the scanning position setting step is performed. A control step of acquiring fundus OCT image data of the eye to be examined at a scanning position; To do.

1 is an external configuration diagram of an ophthalmologic photographing apparatus according to an embodiment. It is a schematic block diagram which shows the optical system and control system of the ophthalmologic imaging device which concerns on a present Example, Comprising: The optical arrangement | positioning at the time of fundus photography is shown. It is a schematic block diagram which shows the optical system and control system of the ophthalmologic imaging device which concerns on a present Example, Comprising: The optical arrangement | positioning at the time of anterior eye part imaging | photography is shown. It is a figure which expands and shows a scanning part. It is a figure which shows the positional relationship of the OCT optical system at the time of anterior eye part imaging | photography. It is a figure which shows the positional relationship of the OCT optical system at the time of fundus photography. It is a flowchart for demonstrating control operation. It is a figure which shows the anterior eye part observation image of a to-be-examined eye. It is a figure explaining alignment control. It is a figure which shows the front image data of an anterior eye part. It is a figure which shows an example of the analysis map which pinpoints the position of a cloudy part. It is a figure explaining the alignment tolerance | permissible_range. It is a figure explaining correction | amendment of the position shift in a to-be-tested eye.

<Overview>
Hereinafter, one exemplary embodiment will be described with reference to the drawings. 1 to 11 are diagrams for explaining the ophthalmologic photographing apparatus according to the present embodiment. In this embodiment, the horizontal direction of the eye to be examined is described as the X direction, the vertical direction as the Y direction, and the axial direction as the Z direction. The surface direction of the fundus may be considered as the XY direction. In addition, the items classified by <> below can be used independently or in association with each other.

  In addition, this indication is not limited to the apparatus described in a present Example. For example, terminal control software (program) that performs the functions of the following embodiments is supplied to a system or apparatus via a network or various storage media, and the system or apparatus control device (for example, CPU) reads the program. It is also possible to execute.

  For example, the ophthalmic imaging apparatus (for example, the ophthalmic imaging apparatus 1) in this embodiment has an OCT optical system (for example, the OCT optical system 2), and acquires OCT image data of the eye to be examined by processing the OCT signal. . For example, the OCT optical system (OCT device) may have Fourier domain optical coherence tomography (FD-OCT) as a basic configuration. For example, as the FD-OCT, spectral domain OCT (SD-OCT) or wavelength sweep type OCT (SS-OCT) may be used. Further, for example, the OCT device may have time domain OCT (TD-OCT) as a basic configuration. Note that, for example, the technique of the present disclosure is based on the standard OCT for detecting the reflection intensity of the test object, the OCT angiography (for example, Doppler OCT) for detecting the motion contrast data of the test object, and the polarization-sensitive OCT ( It may be applied in PS-OCT (Polarization Sensitive OCT) or the like. Further, the present invention may be applied to a multi-function OCT in which standard OCT and PS-OCT are combined.

<OCT optical system>
For example, the OCT optical system detects an OCT signal by measurement light and reference light irradiated on the eye to be examined. In addition, for example, the OCT optical system has a first position corresponding to the first depth zone of the eye to be examined (for example, the anterior eye portion of the eye to be examined) and a second depth zone different from the first depth zone of the eye to be examined. OCT image data at the corresponding second position (for example, the fundus of the eye to be examined) can be acquired.

  Note that the anterior segment of the eye to be examined may be configured to acquire the image data using an OCT optical system. Of course, the anterior eye portion of the eye to be examined may be configured to acquire the image data using an SLO (Scanning Laser Ophthalmoscope), a Shine peak camera, or the like. That is, a light receiving element that irradiates a light beam to the eye to be examined and receives reflected light from the eye to be examined, and that obtains a front image of the eye to be examined based on a light reception signal from the light receiving element may be used.

  For example, the OCT optical system may include a configuration related to an interferometer for obtaining a tomographic image of a test object using the OCT principle. For example, the OCT optical system includes a light source (for example, light source 11), a splitter (for example, coupler 15), a combiner (for example, coupler 15), a detector (for example, detector 40), a reference optical system (for example). For example, a reference optical system 30) may be provided.

  For example, the splitter may split light from the light source into measurement light and reference light. For example, the combiner may combine (interfere) the measurement light and the reference light. For example, a divider and a combiner may be combined. For example, a divider and a combiner may be provided separately. For example, any of a beam splitter, a half mirror, a fiber coupler, a circulator, and the like may be used for the splitter and the combiner.

  For example, the detector may receive interference signal light generated by interference between the measurement light and the reference light. For example, the reference optical system may include a configuration for causing the reference light to travel in the apparatus and interfere with the measurement light.

<Measurement optical system>
For example, the measurement optical system (for example, the measurement optical system 20) may be configured to guide the measurement light to the first position corresponding to the first depth zone of the eye to be examined. For example, the measurement optical system may be configured to guide the measurement light to the second position corresponding to the second depth zone of the eye to be examined. For example, the measurement optical system may include a scanning unit (optical scanner) (for example, the scanning unit 24). For example, the scanning unit scans the measurement light on the first position corresponding to the first depth zone of the eye to be examined. Further, for example, the scanning unit scans the measurement light on the second position corresponding to the second depth zone of the eye to be examined. For example, the scanning unit may include two optical scanners (for example, a galvano mirror 241 and a galvano mirror 242) that deflect measurement light in different directions. For example, a reflection scanner such as a MEMS scanner, a resonant scanner, a polygon mirror, or an acoustooptic device may be used as the optical scanner included in the scanning unit. That is, the optical scanner included in the scanning unit may be any scanner that can deflect the measurement light.

<OCT image data>
For example, the OCT image data includes tomographic image data indicating the reflection intensity characteristics of the eye to be examined, OCT angio image data (for example, OCT motion contrast image data) of the eye to be examined, Doppler OCT image data indicating the Doppler characteristics of the eye to be examined, and the eye to be examined. It may be at least one of polarization characteristic image data indicating the polarization characteristics. Each data may be generated image data, or may be signal data before an image is generated.

  For example, the tomographic image data may be A-scan tomographic image data. For example, the tomographic image data may be B-scan tomographic image data. For example, the B-scan tomographic image data is tomographic image data acquired by scanning the measurement light in any of the XY directions (for example, the X direction) along the scanning line (transverse position). Also good. For example, the tomographic image data may be three-dimensional tomographic image data. For example, the three-dimensional tomographic image data may be tomographic image data acquired by two-dimensionally scanning the measurement light. For example, OCT image data includes OCT front (Enface) image data acquired from three-dimensional tomographic image data (for example, an integrated image integrated in the depth direction, an integrated value of spectrum data at each XY position, a certain fixed value) Brightness data at each XY position in the depth direction, retina surface layer image, etc.).

  For example, the OCT angio image data may be two-dimensional OCT angio image data. For example, the two-dimensional OCT angio image data is OCT angio image data acquired by scanning the measurement light in any of the XY directions (for example, the X direction) along the scanning line (transverse position). There may be. Further, for example, the OCT angio image data may be three-dimensional OCT angio image data. Note that, for example, the three-dimensional OCT angio image data may be OCT angio image data acquired by two-dimensionally scanning the measurement light. Further, for example, the OCT angio image data may be front (En face) motion contrast data acquired from three-dimensional motion contrast data.

  For example, the OCT image data may be OCT image data (anterior segment OCT image data) for the anterior segment of the eye to be examined. For example, the anterior segment OCT image data may be anterior segment cross-sectional image data. That is, the anterior segment cross-sectional image data may be cross-sectional image data between the front surface of the cornea of the eye to be examined and the rear surface of the crystalline lens. Further, for example, the OCT image data may be OCT image data (fundus OCT image data) for the fundus of the eye to be examined.

  For example, in this embodiment, the ophthalmologic photographing apparatus may include an acquisition unit (for example, the control unit 70) that acquires the anterior segment cross-sectional image data of the eye to be examined. In addition, for example, the ophthalmologic photographing apparatus may include a scanning position setting unit (for example, the control unit 70) that sets the scanning position of the measurement light based on the anterior segment cross-sectional image data acquired by the acquisition unit. . Further, for example, the ophthalmologic photographing apparatus includes a control unit (for example, the control unit 70) that controls the OCT optical system and acquires fundus OCT image data of the eye to be examined at the scanning position set by the scanning position setting unit. May be. With such a configuration, the examiner can efficiently acquire the respective image data in the anterior segment and the fundus of the eye to be examined.

<Scanning position setting means>
For example, the scanning position setting unit may acquire analysis information indicating the two-dimensional distribution of the turbid portion by processing the anterior segment cross-sectional image data. For example, the scanning position setting means may be configured to acquire analysis information for the depth direction of the eye to be examined by processing the anterior ocular segment image data. Further, for example, the scanning position setting unit may be configured to acquire analysis information in the vertical and horizontal directions of the eye to be examined by processing front image data obtained by integrating the anterior ocular segment image data.

  For example, the analysis information may be a two-dimensional distribution (analysis map) acquired by analyzing the anterior segment cross-sectional image data. The analysis map may be signal data or image data obtained by imaging the signal data.

  For example, the analysis information may be information indicating the luminance distribution of the anterior segment cross-sectional image data. For example, the information indicating the luminance distribution may be a binarization map acquired by binarizing the anterior segment cross-sectional image data. For example, the binarization map may be acquired by detecting the luminance value for each pixel of the anterior segment cross-sectional image data, or detecting the rise or fall of the luminance in any one of the XYZ directions. May be obtained by When acquiring a binarization map, binarization processing may be performed when a predetermined luminance value is detected and when it is not detected.

  Further, for example, the analysis information may be a turbidity map specifying a turbidity part. For example, the turbidity map may be acquired by detecting the luminance value of the anterior segment cross-sectional image data and performing a turbidity determination process based on the detected luminance value. For example, the turbidity map may determine the turbidity part by determining whether or not the luminance value detected from the anterior segment cross-sectional image data satisfies a predetermined luminance value. Note that the predetermined luminance value used for the determination process may be acquired in advance through experiments or simulations. Note that the turbidity map may be acquired based on other analysis information. In this case, for example, the turbidity portion determination process may be performed based on the binarization map.

  For example, the analysis information acquired as described above may be displayed on a monitor.

  For example, the scanning position setting unit sets the scanning position of the measurement light in the OCT optical system based on the analysis information. For example, with such a configuration, the examiner can easily determine the position of the turbid portion generated in the eye to be examined. Further, the examiner can easily set the scanning position of the measurement light.

  For example, the scanning position setting means specifies the light transmission region based on the analysis information, and sets the scanning position of the measurement light in the OCT optical system so that the measurement light in the OCT optical system passes through the light transmission region. May be. Thus, the examiner can easily set the scanning position of the measurement light so as to avoid the turbid portion generated in the eye to be examined.

  For example, the scanning position setting means may set the scanning position of the measuring light by setting the incident position of the measuring light on the eye to be examined in the OCT optical system. For example, the setting of the scanning position includes at least one of the setting of the incident position of the measuring light, the setting of the incident angle (scanning angle) of the measuring light, and the setting of the scanning range of the measuring light. For example, the scanning position setting unit may perform at least one of these settings, or may combine these settings. For example, the scanning position setting unit may move the OCT optical system as a configuration for setting the scanning position. Further, as a configuration for setting the scanning position, an optical member included in the OCT optical system may be moved. Further, as a configuration for setting the scanning position, an optical member may be inserted into and removed from the optical path of the OCT optical system. With such a configuration, the examiner can set the incident position of the measurement light to the subject eye so as to avoid the turbid portion of the subject eye, and can efficiently perform fundus imaging.

<Alignment of eye to be examined and OCT optical system>
For example, the alignment detection means (for example, the control unit 70) detects the alignment state between the eye to be examined and the optical axis of the OCT optical system based on the positional deviation between the eye to be examined and the alignment reference position. For example, in this case, the alignment reference position is set, and the amount of deviation from the alignment reference position is detected, whereby the alignment state of the eye to be examined may be detected. The alignment reference position may be provided with an allowable range for determining whether or not alignment is appropriate. In addition, when a positional deviation between the eye to be examined and the alignment reference position is detected, the position of the optical axis in the OCT optical system may be corrected based on the positional deviation.

  For example, for the detection of the alignment state, an anterior ocular segment observation image (for example, the anterior ocular segment observation image 60) of the eye to be examined may be analyzed and used. For example, in this case, the index image formed on the cornea of the eye to be examined may be detected from the anterior ocular segment observation image. Further, for example, a configuration in which each part (for example, a black eye part, an iris part, a pupil part, a sclera part (white eye part), etc.) in the anterior eye part is detected from the anterior eye part observation image may be adopted. The analysis process for the anterior ocular segment observation image may be any process that can detect the index image and each part by image processing.

  Further, for example, the alignment detection unit may be configured to set the alignment reference position so that the measurement light is irradiated to the incident position set by the scanning position setting unit. As a result, the examiner can make the measurement light incident on the eye to be examined at a more accurate position.

  For example, the alignment control unit (for example, the control unit 70) drives the driving unit (for example, the moving table 102 and the driving unit 106) that drives the OCT optical system with respect to the eye to be examined, and the OCT optical system for the eye to be examined. The structure which performs automatic alignment may be sufficient. For example, in this case, the optical axis of the OCT optical system may be positioned within the allowable range of the alignment reference position based on the detection result of the alignment detection means. Thereby, alignment is performed with high accuracy, and the examiner can efficiently align (align) the eye to be examined and the OCT optical system.

  For example, the ophthalmologic photographing apparatus according to the present embodiment may control the OCT optical system as the anterior segment cross-sectional image data to acquire the anterior segment OCT image data of the eye to be examined at the first position. In this case, for example, the acquisition unit may acquire the anterior segment OCT image data of the eye to be examined at the first position. Further, for example, the ophthalmologic photographing apparatus according to the present embodiment may control the OCT optical system to acquire fundus OCT image data of the eye to be examined at the second position. In this case, for example, the control unit may acquire fundus OCT image data of the eye to be examined at the second position. With such a configuration, it is possible to easily photograph a part having a different depth zone without requiring a new member or attachment. For example, the anterior segment OCT image data at the first position and the fundus OCT image data at the second position may be acquired at different timings, or may be acquired at the same time. In this case, an optical system that can simultaneously acquire an interference signal in which the return light from the first position interferes with the reference light and an interference signal in which the return light from the second position interferes with the reference light. It is good also as arrangement.

  Further, for example, the control unit may acquire the fundus OCT image data of the eye to be examined at the second position by controlling the OCT optical system after acquiring the anterior ocular segment OCT image by the acquisition unit. As a result, the examiner can continuously take an image of the anterior eye portion and the fundus of the eye to be examined, and perform an efficient measurement.

  For example, the ophthalmologic photographing apparatus according to the present embodiment may sequentially set the scanning position of the measurement light based on the anterior segment cross-sectional image data. In this case, for example, the acquisition unit may acquire the anterior segment cross-sectional image data of the eye to be examined in real time. Further, for example, the scanning position setting unit may sequentially set the scanning position of the measurement light based on the anterior segment cross-sectional image data acquired in real time by the acquisition unit. With such a configuration, the scanning position is always corrected so that the measurement light enters the desired imaging region. Therefore, the examiner can acquire the fundus OCT image data more accurately.

  For example, the ophthalmologic photographing apparatus according to the present embodiment may acquire the anterior ocular segment cross-sectional image data as the anterior ocular segment cross-sectional image data of the eye to be examined. For example, in this case, the acquisition unit acquires the anterior ocular segment three-dimensional cross-sectional image data as the anterior ocular segment cross-sectional image data of the eye to be examined. With such a configuration, the position of the turbid portion in the eye to be examined can be specified not only in the XY direction but also in the Z direction. Therefore, the examiner can acquire the fundus OCT image data of the eye to be examined with high accuracy.

<Example>
Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. FIG. 1 is an external configuration diagram of an ophthalmologic photographing apparatus 1 according to the present embodiment. For example, the ophthalmologic photographing apparatus 1 includes a base 101, a moving base 102, a measurement unit 103, an operation member 104, a face support unit 105, a drive unit 106, and a monitor 75. For example, the movable table 102 is movable in the left-right direction (X direction) and the front-back direction (Z direction) with respect to the base 101. For example, the measurement unit 103 houses an optical system described later. For example, the face support unit 105 is fixed to the base 101 in order to support the subject's face. For example, the drive unit 106 can move in the vertical direction (Y direction) with respect to the moving table 102. For example, the monitor 75 displays OCT image data described later.

  For example, the operating member (joystick) 104 is provided with a moving mechanism that moves the measuring unit 103 relative to the eye E to be examined. More specifically, for example, the joystick 104 includes a sliding mechanism (not shown) that slides the moving base 102 in the XZ direction on the base 101. For example, when the joystick 104 is operated, the moving base 102 slides on the base 101 in the XZ direction. The joystick 104 is provided with a rotation knob. For example, when the joystick 104 is rotated, the drive unit 106 is driven in the Y direction, and the measurement unit 103 is moved in the Y direction. For example, the measurement unit 103 can be moved with respect to the eye E by this.

  In the present embodiment, the configuration in which the measurement unit 103 is moved in the Y direction by the drive unit 106 has been described as an example, but the present invention is not limited to this. For example, the measuring unit 103 may be provided with a moving mechanism that allows the measuring unit 103 to move in the XYZ directions. In this case, for example, a moving mechanism in the X, Y, and Z directions of the measuring unit 103 with respect to the eye E is used when the measuring unit 103 is finely moved, and a sliding mechanism of the moving table 102 coarsely moves the measuring unit 103. It may be used when making it.

  For example, the ophthalmologic imaging apparatus 1 in the present embodiment is an optical tomographic interferometer (hereinafter referred to as OCT device 1) that acquires depth information of the eye E to be examined. For example, the OCT device 1 may be Fourier domain optical coherence tomography (FD-OCT: Fourier Domain OCT) or time domain OCT (TD-OCT: Time Domain OCT). Typical examples of FD-OCT include spectral domain OCT (SD-OCT) and swept source OCT (SS-OCT). Of course, the present disclosure is applied to these apparatuses. Can be done.

  2A and 2B are schematic configuration diagrams illustrating an optical system and a control system of the ophthalmologic photographing apparatus 1 according to the present embodiment. FIG. 2A shows an optical arrangement at the time of fundus photography, and FIG. 2B shows an optical arrangement at the time of anterior eye photography. The OCT device 1 shown in FIGS. 2A and 2B mainly includes an interference optical system (OCT optical system) 2, a measurement optical system (light guide optical system) 20, and a control unit 70. The OCT device 1 in the present embodiment further includes a fixation target projection unit 90 (second optical system), a storage unit (memory) 72, an operation unit 74, and a monitor 75. For example, the OCT optical system 2, the measurement optical system 20, and the fixation target projection unit 90 are accommodated in the measurement unit 103 described above. In addition, for example, the control unit 70 and the storage unit 72 are accommodated in the moving table 102 described above.

  First, the OCT optical system 2 will be described. The OCT optical system 2 divides the light beam emitted from the light source 11 into measurement light and reference light. The OCT optical system 2 guides the measurement light to the eye E and guides the reference light to the reference optical system 30. Then, the OCT optical system 2 detects interference between the measurement light irradiated to the eye E and the reference light by the detector (light detector) 40. More specifically, in the present embodiment, the measurement light reflected (or backscattered) by the eye E and the interference light generated by combining the reference light are detected by the detector 40, and the interference signal is acquired.

  For example, in the case of SD-OCT, a low-coherent light source (broadband light source) is used as the light source 11, and the detector 40 is provided with a spectroscopic optical system (spectrum meter) that separates interference light into frequency components. For example, the spectrum meter is composed of a diffraction grating and a line sensor.

  For example, in the case of SS-OCT, a wavelength scanning light source (wavelength variable light source) that changes the emission wavelength at a high speed in time is used as the light source 11, and the detector 40 includes, for example, a single light receiving element. Provided. The light source 11 includes, for example, a light source, a fiber ring resonator, and a wavelength selection filter. Examples of the wavelength selection filter include a combination of a diffraction grating and a polygon mirror, and a filter using a Fabry-Perot etalon.

  In the OCT device 1, the optical arrangement of the measurement optical system 20 is switched. As an example, the optical arrangement shown in FIG. 2A may be switched to the optical arrangement shown in FIG. 2B. In the optical arrangements of FIGS. 2A and 2B, the depth zones of the portions where the tomographic image is captured by the OCT device 1 are different from each other. Hereinafter, in this embodiment, a case where SD-OCT is applied to the OCT device 1 will be described as an example.

  The OCT optical system 2 illustrated in FIGS. 2A and 2B includes a light source 11, optical fibers 15a, 15b, 15c, and 15d, a splitter 15, a reference optical system 30, and a detector 40.

  The light source 11 emits low coherent light used as measurement light and reference light of the OCT optical system 2. As the light source 11, for example, an SLD light source or the like may be used. More specifically, for example, the light source 11 may emit light having a center wavelength between λ = 800 nm and 1100 nm. Light from the light source 11 is guided to the splitter 15 through the optical fiber 15a.

  The optical fibers 15a, 15b, 15c, and 15d connect the splitter 15, the light source 11, the measurement optical system 20, the reference optical system 30, the detector 40, and the like by allowing light to pass therethrough.

  The splitter 15 splits the light guided from the light source 11 (through the optical fiber 15a) into measurement light and reference light. The measurement light is guided to the measurement optical system 20 through the optical fiber 15b. On the other hand, the reference light is guided to the reference optical system 30 via the optical fiber 15 c and the polarizer 31.

  2A and 2B, the divider 15 also serves as a coupling unit (combiner) that couples the return path of the measurement light guided to the eye E and the reference light (details will be described later). To do). Such a splitter 15 may be, for example, a fiber coupler. Hereinafter, the divider 15 is referred to as a coupler 15.

  For convenience, the measurement optical system 20 will be described here. For example, the measurement optical system 20 guides measurement light to the eye E to be examined. As an example, the measurement optical system 20 shown in FIGS. 2A and 2B includes a collimator lens 21, a light beam diameter adjustment unit 22, a condensing position variable optical system (condensing position variable lens system) 23, a scanning unit (optical scanner) 24, A mirror 25, a dichroic mirror 26, and an objective optical system 27 are included.

  The collimator lens 21 collimates the measurement light emitted from the end 16b of the optical fiber 15b.

  The light beam diameter adjusting unit 22 is disposed in the optical path between the OCT optical system 2 and the scanning unit 24 (that is, the optical scanner), and is used for changing the light beam diameter of the measurement light in the optical path. 2A and 2B, the light beam diameter adjusting unit 22 is provided in the optical path between the coupler 15 and the scanning unit 24 in the measurement optical system 20. The light beam diameter adjusting unit 22 may be, for example, at least one of an aperture that can be inserted and removed from the optical path by an insertion and removal mechanism, a variable beam expander, and a variable aperture that can adjust the diameter of the aperture. For example, in this embodiment, the beam diameter adjusting unit 22 shown in FIGS. 2A and 2B is a variable beam expander. As shown in FIGS. 2A and 2B, the variable beam expander may include, for example, two lenses 22a and 22b and a drive unit 22c. The drive unit 22 c changes the positional relationship in the optical axis direction between the lenses 22 a and 22 b based on a control signal from the control unit 70. Thereby, the beam diameter (and numerical aperture NA) of the measurement light is changed.

  The condensing position variable optical system 23 is used to change the condensing position of the measurement light in the direction of the optical axis L1. The condensing position variable optical system 23 has at least one lens 23a, and adjusts the condensing position of the measurement light with respect to the direction of the optical axis L1 using the lens 23a. 2A and 2B, the condensing position variable optical system 23 is provided in the optical path between the coupler 15 and the scanning unit 24. In this embodiment, the condensing position variable optical system 23 is disposed between the light beam diameter adjusting unit 22 and the scanning unit 24. However, the arrangement of the light beam diameter adjusting unit 22 and the condensing position variable optical system 23 is not necessarily limited to this. For example, they may be replaced with each other. Further, a relay optical system or the like may be interposed between the two. The lens 23a constitutes a focus optical system that determines the collection position of the measurement light with respect to the optical axis L1 direction. The condensing position variable optical system 23 may be configured by the lens 23a alone, or may be configured together with the lens 23a and other optical elements. The condensing position variable optical system 23 is realized, for example, with a configuration that adjusts either the refractive power of the lens 23a or the positional relationship between the objective optical system 27 and the lens 23a in the optical axis L1 direction. The positional relationship between the objective optical system 27 and the lens 23a is adjusted by, for example, the position of the lens 23a in the direction of the optical axis L1, the optical path length between the lens 23a and the objective optical system 27a, and the lens relative to the measurement optical path. It may be realized by either insertion or removal. In this case, the drive unit (actuator) that moves the lens 23 a in the intended direction is controlled by the control unit 70.

  In the example of FIGS. 2A and 2B, the lens 23a is a variable focus lens. The lens 23a can change the focal position while being stationary with respect to the optical axis L1. The lens 23 a changes the refractive power according to the magnitude of the applied voltage set by the control unit 70. A liquid crystal lens or the like is known as a typical variable focus lens. The lens with variable refractive power is not limited to a liquid crystal lens, and may be, for example, a liquid lens, a nonlinear optical member, a molecular member, a rotationally asymmetric optical member, or the like.

  The scanning unit 24 includes an optical scanner that deflects the measurement light from the OCT optical system in order to scan the measurement light. For example, the scanning unit 24 may include two galvanometer mirrors 241 and 242 (an example of an optical scanner). In the example of FIG. 3, reference numeral 241 denotes an X scanning galvanometer mirror, and 242 denotes a Y scanning galvanometer mirror. Each of the galvanometer mirrors 241 and 242 may include mirror units 241a and 242a and driving units 241b and 242b (for example, motors) that rotate the respective 241a and 242a. The controller 70 changes the traveling direction of the measurement light by independently controlling the directions of the galvanometer mirrors 241 and 242. As a result, the measurement light can be scanned in the vertical and horizontal directions with respect to the eye E. The scanning unit 24 can use an optical scanner other than the galvanometer mirrors 241b and 242b. For example, a reflective scanner (for example, a MEMS scanner, a resonant scanner, a polygon mirror, or the like) may be used, or an acousto-optic element may be used.

  In the example of FIGS. 2A and 2B, the measurement light whose traveling direction has been changed by the scanning unit 24 is reflected by each of the mirror 25 and the dichroic mirror 26 in which the mirror surfaces are arranged with a right angle therebetween. As a result, the measurement light is folded back in the direction opposite to that emitted from the scanning unit 24. As a result, the measurement light is guided to the objective optical system 27.

  In the present embodiment, the objective optical system 27 is fixedly arranged. More specifically, the objective optical system 27 is arranged between the scanning unit 24 and the eye E in the measurement optical system 20. The objective optical system 27 guides the measurement light deflected by the optical scanner (galvano mirrors 241 and 242 in this embodiment) to the eye E to be examined. In this embodiment, the objective optical system 27 is formed as a lens system (objective lens system) having a positive power. For this reason, the measurement light from the scanning unit 24 is bent toward the optical axis L <b> 1 by passing through the objective optical system 27. 2A and 2B, for convenience, the objective optical system 27 is shown as an optical system including two lenses 27a and 27b. However, the number of lenses constituting the objective optical system 27 is not limited to this. . The objective optical system 27 may be replaced with one lens or may be replaced with three or more lenses (for example, see FIGS. 4A and 4B). The objective optical system 27 is not limited to a lens system. For example, the objective optical system 27 may be a mirror system, an optical system based on a combination of a lens and a mirror, or an optical system other than a lens and a mirror. An optical system including a member may be used.

  In such a measurement optical system 20, when the measurement light is emitted from the end portion 16 b of the optical fiber 15 b, the measurement light is collimated by the collimator lens 21. Thereafter, the measurement light passes through the light beam diameter adjusting unit 22 and the condensing position variable optical system 23 and reaches the scanning unit 24. The measurement light is reflected by two galvanometer mirrors provided in the scanning unit 24 and then further reflected by the mirror 25 and the dichroic mirror 26. As a result, the measurement light enters the objective optical system 27. Then, the measurement light passes through the objective optical system 27 and is guided to the eye E to be examined. Thereafter, the measurement light is reflected or scattered by the eye E, and as a result, the measurement light system 20 travels backward to enter the end portion 16b of the optical fiber 15b. The measurement light incident on the end portion 16b enters the coupler 15 through the optical fiber 15b.

  The OCT device 1 includes a drive unit (actuator). The drive unit displaces the relative position of the scanning unit 24 (that is, the galvanometer mirrors 241 and 242 which are optical scanners) with respect to the objective optical system 27 and the relative position of the measurement optical system 20 in the optical axis L1 direction. More specifically, the relative position of the scanning unit 24 with respect to the rear focal position (or its conjugate position) of the objective optical system 27 is changed by driving the driving unit. Due to the displacement of the relative position, the turning position of the measurement light is changed with respect to the direction of the optical axis L1 (details will be described later). The drive unit displaces the relative distance of the scanning unit 24 with respect to the objective optical system 27 by moving at least one of the scanning unit 24 and the optical member disposed between the objective optical system 27 and the scanning unit 24. You may let them. 2A and 2B, the OCT device 1 has a drive unit 50. The distance (optical path length) between the objective optical system 27 and the scanning unit 24 is changed by driving the driving unit 50, and thereby the relative position of the scanning unit 24 with respect to the objective optical system 27 is displaced. This relative position is changed in correspondence with the depth zone of the eye E to be imaged.

  In the example of FIGS. 2A and 2B, the driving unit 50 integrally moves two mirrors (mirror 25 and dichroic mirror 26) each having a mirror surface sandwiching a right angle in a predetermined direction. In the present embodiment, the objective optical system 27 is moved in the optical axis direction. As a result, the optical path length from the scanning unit 24 to the objective optical system 27 is changed (for example, FIG. 2A → FIG. 2B, FIG. 2B → FIG. 2A). For example, when the depth zone where a tomographic image is obtained is switched between the anterior segment Ec and the fundus oculi Er, it is necessary to change the optical path length from the scanning unit 24 to the objective optical system 27 relatively large. On the other hand, in the example of FIG. 2A, the measurement light emitted from the scanning unit 24 is folded back by two mirrors, so that when the two mirrors are moved, from the scanning unit 24 to the objective optical system 27. (In other words, the amount of displacement of the scanning unit 24 in the direction of the optical axis L1 with respect to the objective optical system 27) can be twice the amount of movement of the two mirrors 25 and 26. Therefore, a space necessary for displacing the position of the scanning unit 24 with respect to the objective optical system 27 with respect to the optical axis L1 direction of the measurement optical system 20 can be suppressed.

  2A and 2B, the OCT device 1 may include a sensor 51 for detecting the position of the scanning unit 24 with respect to the objective optical system 27. Various devices can be used as the sensor 51. For example, a linear displacement sensor such as a potentiometer may be applied as the sensor 51.

  Here, the description returns to the OCT optical system 2. The reference optical system 30 generates reference light. The reference light is light that is combined with the reflected light of the measurement light reflected by the fundus Er. The reference optical system 30 may be a Michelson type or a Mach-Zehnder type. The reference optical system 30 illustrated in FIGS. 2A and 2B is formed by a reflection optical system (for example, a reference mirror 34). In the example of FIGS. 2A and 2B, the light from the coupler 15 is reflected back by the reflection optical system, and is returned to the coupler 15 again. As a result, the light is guided to the detector 40. The reference optical system 30 may be formed by a transmission optical system (for example, an optical fiber). In this case, the reference optical system 30 guides the reference light divided by the coupler 15 to the detector 40 by transmitting the reference light without returning to the coupler 15.

  2A and 2B, the reference optical system 30 has an optical fiber 15c, an end portion 16c of the optical fiber 15c, a collimator lens 33, and a reference mirror 34 in the optical path from the splitter 15 to the reference mirror 34. doing. The optical fiber 15c is rotated by the drive unit 32 in order to change the polarization direction of the reference light. That is, the optical fiber 15c and the drive unit 32 are used as a polarizer 31 for adjusting the polarization direction. The polarizer is not limited to the above-described configuration, and any polarizer may be used as long as the polarization state of the measurement light and the reference light is substantially matched by driving the polarizer arranged in the optical path of the measurement light or the optical path of the reference light. . For example, a half-wave plate or a quarter-wave plate can be used, or one that changes the polarization state by applying pressure to the optical fiber to deform it can be applied.

  The polarizer 31 (polarization controller) may be configured to adjust the polarization direction of at least one of the measurement light and the reference light in order to match the polarization directions of the measurement light and the reference light. For example, the polarizer 31 may be configured in the optical path of the measurement light.

  The reference mirror 34 is displaced with respect to the optical axis direction L2 by the reference mirror driving unit 34a. As the reference mirror 34 is displaced, the optical path length of the reference light is adjusted.

  The reference light emitted from the end 16 c of the optical fiber 15 c is converted into a parallel light beam by the collimator lens 33 and reflected by the reference mirror 34. Thereafter, the reference light is collected by the collimator lens 33 and enters the end 16c of the optical fiber 15c. The reference light incident on the end 16c reaches the coupler 15 via the optical fiber 15c and the optical fiber 31 (polarizer 31).

  In the example of FIGS. 2A and 2B, the reference light reflected by the reference mirror 34 and the return light of the measurement light guided to the eye E (that is, the measurement light reflected or scattered by the eye E) Are combined by the coupler 15 to be interference light. This interference light is emitted from the end portion 16d through the optical fiber 15d. As a result, the interference light is guided to the detector 40.

  In order to obtain an interference signal for each frequency (wavelength), the detector (here, the spectrometer unit) 40 separates the interference light by the reference light and the measurement light for each frequency (wavelength), and the split interference light is obtained. Receive light.

  The detector 40 shown in FIGS. 2A and 2B may include, for example, an optical system (not shown) such as a collimator lens, a grating mirror (diffraction grating), and a condenser lens. For example, a one-dimensional light receiving element (line sensor) may be applied to the main body (light receiving element portion) of the detector 40. The detector 40 is sensitive to the wavelength of light emitted from the light source 11. As described above, when infrared light is emitted from the light source 11, the detector 40 having infrared sensitivity can be used.

  The interference light emitted from the end portion 16b is converted into parallel light by the collimator lens 21, and then split into frequency components by a grating mirror (not shown). Then, the interference light split into frequency components is condensed on the light receiving surface of the detector 40 via a condenser lens (not shown). Thereby, spectrum information (spectrum signal) of interference fringes on the detector 40 is obtained. The spectrum information is input to the control unit 70 and analyzed by the control unit 70 using Fourier transform. As a result of the analysis, a tomographic image of the eye E is formed. In addition, as an analysis result, information in the depth direction of the eye E can be measured.

  Here, the control unit 70 can acquire a tomographic image by scanning the measurement light in the transverse direction of the eye E with the scanning unit 24. For example, by scanning in the X direction or the Y direction, a tomographic image on the XZ plane or the YZ plane of the fundus Er to be examined can be acquired (in this embodiment, the measurement light is primarily applied to the fundus Er in this way. A method of performing original scanning and obtaining a tomographic image is referred to as B-scan). Note that the acquired tomogram is stored in the storage unit 72 connected to the control unit 70. Further, by controlling the driving of the scanning unit 24 and scanning the measurement light in the XY direction two-dimensionally, a two-dimensional moving image of the subject's fundus oculi Er in the XY direction and the tertiary of the fundus oculi Er of the subject's eye An original image can be formed based on the output signal from the detector 40.

  Next, the fixation target projection unit 90 will be described. The fixation target projecting unit 90 has an optical system for guiding the line-of-sight direction of the eye E. The fixation target projection unit 90 includes a fixation target (fixation light source 91) to be presented to the eye E. The fixation target projection unit 90 may be configured to guide the eye E in a plurality of directions. Here, the dichroic mirror 26 has a characteristic of transmitting light of a wavelength component used as measurement light of the OCT optical system 2 and transmitting light of a wavelength component used for the fixation target projection unit 90. Therefore, the fixation target luminous flux emitted from the fixation target projection unit 90 is irradiated onto the fundus Er of the eye E through the objective optical system 27. As a result, the subject can fixate.

<Control system>
Next, the control system of the OCT device 1 will be described. The control unit (controller) 70 controls each unit of the OCT device 1. For example, the control unit 70 may include a CPU (processor) and a memory. In the present embodiment, the control unit 70 acquires the depth information of the eye E by processing an output signal (that is, an interference signal) from the detector 40, for example. Depth information includes image information such as tomograms, dimensional information indicating the dimensions of each part of the eye E, information indicating the amount of movement in the irradiated region of the measurement light, and a (complex number) analysis signal including information on polarization characteristics, And / or the like. In the present embodiment, the control unit 70 also serves as an image processor that forms a tomographic image of the eye E based on the interference signal. Further, the control unit 70 according to the present embodiment performs various image processing in addition to the formation of the tomographic image. The image processing may be performed by a dedicated electronic circuit (for example, an image processing IC not shown) provided in the control unit 70, or may be performed by a processor (for example, CPU).

  A storage unit 72, an operation unit (user interface) 74, and a monitor 75 are connected to the control unit 70 (see FIGS. 2A and 2B). The storage unit 72 may include a rewritable non-transitory storage medium, and may be any one of a flash memory and a hard disk, for example. Images and measurement data obtained as a result of photographing and measurement are stored in the storage unit 72. The program and fixed data defining the imaging sequence in the OCT device 1 may be stored in the storage unit 72 or may be stored in the ROM in the control unit 70. In addition to the light source 11, the detector 40, and various driving units 22c, 23a, 241a, 242b, 32, 34a, 50, a sensor 51 and the like are connected.

<Shooting depth zone switching operation>
Next, with reference to FIG. 4A and FIG. 4B, the imaging depth zone switching operation in the OCT device 1 configured as described above will be described. In the present embodiment, in order to switch the imaging depth zone, the control unit 70 controls the drive unit 50 to displace the turning position of the measurement light in the eye E with respect to the optical axis L1 direction. The turning position is displaced according to the relative position of the scanning unit 24 with respect to the objective optical system 27. That is, in this embodiment, the control unit 70 changes the relative position of the scanning unit 24 with respect to the objective optical system 27 by the driving unit 50, and as a result, the swiveling position of the measurement light in the eye E with respect to the optical axis L1 direction. adjust. At that time, the control unit 70 changes the turning position of the measurement light at least between the first position and the second position. The first position corresponds to the first depth zone of the eye E, and the second position corresponds to the second depth zone of the eye E different from the first depth zone. The second position is different from the first position with respect to the optical axis direction of the measurement optical system (the depth direction of the eye E).

  The first position and the second position are the number of Fourier transform images (or the number of pupil images) of the pupil formed in the section from the scanning unit 24 to the subject side end of the objective optical system 27. However, the turning positions may be different from each other. 4A and 4B, the subject-side end of the objective optical system 27 is a lens surface that is disposed closest to the eye E in the objective optical system 27. If the objective optical system 27 is a mirror system, the mirror surface arranged closest to the eye E is the subject-side end. By switching the turning position between the first position and the second position, the even / odd number of the Fourier transform images (or the number of pupil images) of the pupil in the section may be switched (details will be described later). ). At this time, among the number of Fourier transform images of the pupil and the number of pupil images, even / odd in both may be switched, or only one may be switched. In the first position and the second position, even / oddness of the number of Fourier transform images (or the number of pupil images) of the pupil in the section is switched, for example, on one of the first position and the second position, A tomographic image of the anterior eye portion is easily captured well, and on the other hand, a tomographic image of the fundus oculi Er is easily captured well. Note that the Fourier transform image of the pupil is formed at a position where the parallel luminous flux emitted from the pupil is condensed (for example, the position of Fr in FIG. 4B).

  Here, FIG. 4A shows a positional relationship of each part of the measurement optical system 20 at the time of photographing the anterior eye part (the first depth zone in the present embodiment). FIG. 4B shows the positional relationship of each part of the measurement optical system 20 at the time of photographing the fundus oculi Er (second depth zone in the present embodiment). 4A and 4B, the mirror 25 and the dichroic mirror 26 are not shown. 4A and 4B, Ff represents the front focal point of the objective optical system 27, and Fr represents the rear focal point of the objective optical system 27. Ic indicates a position conjugate with the pupil of the eye E with respect to the objective optical system 27.

  In the example of FIGS. 4A and 4B, the control unit 70 controls the drive unit 50 at the time of photographing the anterior eye part and at the time of photographing the fundus Er, so that the turning position of the measurement light is set in the direction of the optical axis L1. Switch on. At this time, the control unit 70 may adjust the optical path length in the reference optical system 30 in conjunction with the change in the relative position between the objective optical system 27 and the scanning unit 24. At this time, the control unit 70 may switch the condensing position of the measurement light by controlling the condensing position variable optical system 23. Further, the control unit 70 may control the light beam diameter adjusting unit 22 to adjust the NA. Such a change in the position of the scanning unit 24 (in other words, a change in the imaging depth band) may be executed based on, for example, a switching signal output from the operation unit 74 to the control unit 70. Further, the control unit 70 may automatically switch in a series of shooting sequences. Details will be described below.

<Anterior segment photography>
As shown in FIG. 4A, at the time of anterior segment imaging, the control unit 70 brings the scanning unit 24 closer to the objective optical system 27 at the time of fundus imaging (see FIG. 4B). As a result, the turning position of the measurement light is set to a position where the number of Fourier transform images of the pupil is an even number. In the example of FIG. 4A, the number of Fourier transform images of the pupil is “0”. In this case, the control unit 70 may arrange the scanning unit 24 at the rear focal position Fr of the objective optical system 27. For example, the control unit 70 positions the scanning unit 24 to the rear focal position Fr based on the detection signal of the sensor 51. At the time of positioning, the optical scanner (galvanometer mirrors 241 and 242 in this embodiment) constituting the scanning unit 24 is in the vicinity of the rear focal position Fr within a range of allowable measurement accuracy (or tomographic image quality). It is desirable to be arranged in. For example, the control unit 70 may position the intermediate point Cp (see FIG. 2) of the two optical scanners (galvano mirrors 241 and 242 in this embodiment) at the rear focal position Fr, or one of them. The reflection surface of the optical scanner may be located at the rear focal position Fr. Of course, other arrangements are possible.

  As a result of the scanning unit 24 being arranged at the rear focal position Fr of the objective optical system 27, the principal ray of the measurement light becomes telecentric (or substantially telecentric) on the object side (the eye side to be examined) of the objective optical system 27. That is, in this embodiment, an optical system (referred to as a scanning optical system for convenience) composed of the scanning unit 24 and the objective optical system 27 is formed as an object side telecentric optical system. In this case, the turning position of the measurement light in the eye E (the first position in the present embodiment) can be considered as an infinite point on the optical axis L1. In this case, the principal ray of the measurement light emitted from the front surface of the objective optical system 27 (that is, the lens surface arranged closest to the eye to be examined) to the pupil surface of the eye E is reflected by the scanning unit 24. Regardless of the direction of the measurement light, it is parallel (substantially parallel) to the optical axis L1. Thereby, the magnification change of the picked-up image by the change of the position of the eye E to be examined can be reduced. As a result, it is possible to accurately measure the distance from the photographed anterior segment tomogram. Further, by irradiating the telecentric measurement light at the time of anterior eye photography, it becomes difficult to cause distortion of the tomographic image due to the displacement of the eye E in the working distance direction. As a result, the examiner can observe a tomographic image with little distortion, and it is easy to make a diagnosis using the tomographic image. Furthermore, by irradiating the telecentric measurement light during anterior segment imaging, the recovery efficiency of the return light (reflected light or backscattered light) from the measured part is improved, so that the peripheral part of the image is not darkened. it can.

  4A illustrates the case where the scanning unit 24 is arranged at the rear focal position Fr of the objective optical system 27 under the control of the driving unit 50 in order to irradiate the telecentric measurement light. The driving unit 50 may be controlled so that the scanning unit 24 is arranged at a conjugate position with respect to the side focal position Fr and the lens system. In the present disclosure, “conjugate” is not necessarily limited to an optically complete conjugate relationship. In the present disclosure, the “conjugate” relationship may be a positional relationship deviated from the complete conjugate relationship within the range of allowable measurement accuracy (or tomographic image quality) in addition to the complete conjugate relationship.

  In the present embodiment, the control unit 70 sets the optical path length of the reference optical system 30 at the time of anterior ocular imaging in accordance with the optical path length of the measurement light from the anterior ocular segment to the fundus Er with respect to the fundus imaging. Set it short. More specifically, the optical path length of the reference optical system 30 is adjusted so that the optical path length of the return light of the measurement light from the anterior eye part and the optical path length of the reference optical system 30 are the same. As a result, an interference signal obtained by satisfactorily interfering the return light of the measurement light and the reference light can be obtained with the detector 40. The control unit 70 forms an image based on the interference signal, whereby a tomographic image of the anterior segment Ec in the eye E is obtained.

  As shown in FIG. 4A, the control unit 70 controls the condensing position variable optical system 23 to set the condensing position of the measurement light in the anterior eye part when photographing the anterior eye part. In this case, the control unit 70 may control the condensing position variable optical system 23 so that the measurement light incident on the scanning unit 24 from the lens 23a is slightly diffused. As a specific example, the control unit 70 may set the refractive power of the variable focus lens (lens 23a) to a negative value. Thereby, it is preferable that a condensing position is set in the middle of the front surface of the cornea and the rear surface of the crystalline lens (more preferably, in the middle of the front surface of the crystalline lens and the rear surface of the crystalline lens). In this case, a region having a relatively high resolution in the tomographic image is wider than in the case where the condensing position is set on the corneal surface.

  Further, as shown in FIG. 4A, the control unit 70 controls the light beam diameter adjusting unit 22 during the anterior segment imaging, and the optical path between the OCT optical system 2 and the scanning unit 24 (that is, the optical scanner). The beam diameter of the measurement light at is made thinner than that at the time of fundus photography. Thereby, the NA of the light beam incident on the eye E is reduced. That is, the depth of focus with respect to the objective optical system 27 is increased as compared with fundus photography. As a result, with respect to the depth direction of the eye E, the range in which the interference signal from the detector 40 can be obtained satisfactorily increases. Therefore, the optical coherence tomograph 1 makes it easy to image a wide range of the anterior segment (for example, from the front of the cornea to the back of the crystalline lens).

<Fundus photography>
On the other hand, as shown in FIG. 4B, at the time of fundus photographing, the control unit 70 moves the scanning unit 24 away from the objective optical system 27 at the time of anterior eye fundus photographing (see FIG. 4A). As a result, the turning position of the measurement light is set to a position where the number of Fourier transform images of the pupil is an odd number. In the example of FIG. 4B, the number of Fourier transform images of the pupil is “1”. In this case, the control unit 70 may arrange the scanning unit 24 at a position Ic conjugate with the pupil of the eye E with respect to the objective optical system 27. For example, the control unit 70 positions the scanning unit 24 to the pupil conjugate position Ic based on the detection signal of the sensor 51. For example, the scanning unit 24 is arranged so that an intermediate point Cp (see FIG. 2) of two optical scanners (galvano mirrors in the present embodiment) constituting the scanning unit 24 is pupil conjugate with respect to the objective optical system 27. Also good. Of course, other arrangements are possible. When the scanning unit 24 is disposed at the pupil conjugate position Ic, the measurement light emitted from the front surface (lens surface closest to the eye to be examined) of the objective optical system 27 with the driving of the scanning unit 24 is centered on the pupil position. Turn as (turning point). That is, in this case, the turning position of the measurement light in the eye E (second position in the present embodiment) is set to the pupil position. As a result, the measurement light can be scanned with the fundus Er while suppressing the vignetting of the measurement light. As a result, a tomographic image of the fundus oculi Er can be captured over a wide range of the fundus oculi Er. In the present embodiment, the case where the scanning unit 24 is arranged at the pupil conjugate position Ic has been described at the time of fundus photographing. However, the position may be a position that is substantially conjugate with a predetermined part of the anterior segment. It may be.

  Further, in this embodiment, the control unit 70 sets the optical path length of the reference optical system 30 at the time of fundus photographing to the time of anterior eye photographing according to the optical path length of the measurement light from the anterior eye part to the fundus Er. Set longer. More specifically, the optical path length of the reference optical system 30 is adjusted so that the optical path length of the return light of the measurement light from the fundus Er is the same as the optical path length of the reference optical system 30. As a result, an interference signal in which the return light of the measurement light from the fundus Er and the reference light interfere well can be obtained from the detector 40. The control unit 70 forms an image based on the interference signal, whereby a tomographic image of the fundus Er in the eye E is obtained.

  As shown in FIG. 4B, the control unit 70 controls the condensing position variable optical system 23 to set the condensing position of the measurement light on the fundus Er at the time of fundus photographing. In this case, the control unit 70 may control the converging position variable optical system 23 so that the measurement light is once condensed at the rear focal position Fr in the objective optical system 27. For example, the control unit 70 adjusts the refractive power of the variable focus lens (lens 23a) to a positive default value. As a result, since the measurement light is collimated by the objective optical system 27, the measurement light is collected on the fundus of the eye E to be examined with no refraction error. When there is a refraction error in the eye E, the controller 70 may offset the condensing position by that amount. As a result, a tomographic image of the fundus oculi Er can be easily acquired.

  Further, as shown in FIG. 4B, the control unit 70 determines the light beam diameter of the measurement light in the optical path between the OCT optical system 2 and the scanning unit 24 (that is, the optical scanner) at the time of fundus photographing. Thicken against time. As a result, since the NA of the measurement light incident on the objective optical system 27 is increased, it is easy to obtain a high-resolution fundus tomographic image. Note that the depth of focus is narrower than that during anterior eye photography.

  As described above, in the example of FIGS. 4A and 4B, the control unit 70 determines the anterior segment based on the output signal from the detector 40 when the turning position of the measurement light in the eye E is displaced to the first position. A tomographic image is generated. Further, when the turning position of the measurement light is displaced to the second position, the control unit 70 generates a tomographic image of the fundus Er based on the output signal from the detector 40.

  When the tomographic image of the anterior eye portion Ec and the tomographic image of the fundus oculi Er are generated, the control unit 70 determines each tomographic image as a distance between depth zones corresponding to each tomographic image (that is, the anterior eye portion Ec). A composite image may be generated by combining based on distance information indicating (a distance between the first depth band) and the fundus Er (second depth band). The distance information may be, for example, a fixed value such as an average value or a standard value in the human eye, or may be an actual measurement value in the eye E obtained by an eye dimension measuring device such as an axial length measuring device. Good. Moreover, distance information may be acquired based on the output signal from the detector 40 in the OCT device 1, and the control unit 70 may generate a composite image using this distance information. Further, the composite image is not limited to an image including the whole of each tomographic image, but may indicate an image obtained by combining a part of each tomographic image. Further, the composite image may be an image in which each tomographic image is superimposed on an eyeball model image imitating an eyeball.

  In this embodiment, the relative position of the scanning unit 24 with respect to the objective lens system 27 is set to the pupil conjugate position Ic, so that a tomographic image of the fundus Er can be captured. From there, when the scanning unit 24 is set to the rear focal point Fr of the objective optical system 27 while the position of the objective lens system 27 is fixed, the scanning optical system composed of the scanning unit 24 and the objective optical system 27 becomes the object side telecentric optical. It becomes a system and a tomographic image of the anterior segment can be taken. As described above, the OCT device 1 does not change the working distance (for example, the distance from the cornea of the eye E to the subject side end of the objective optical system 27) and the tomographic image of the anterior eye and the fundus Er. Can be obtained.

  Further, in this embodiment, the control unit 70 controls the condensing position variable optical system 23 so that the condensing position of the measurement light is changed to the optical axis in conjunction with the change of the relative position of the scanning unit 24 with respect to the objective optical system 27. Change in the L1 direction. More specifically, the control unit 70 controls the condensing position variable optical system 23 so that the condensing position of the measurement light is set to an imaging depth zone corresponding to the position of the scanning unit 24. That is, when the turning position is displaced to a position corresponding to the anterior eye part, the control unit 70 focuses the measurement light on the anterior eye part and sets the turning position to a position corresponding to the fundus Er. When displaced, the condensing position variable optical system 23 is controlled in conjunction with the relative position of the scanning unit 24 with respect to the objective optical system 27 so that the measurement light is condensed on the fundus Er. As a result, a tomographic image in each depth zone can be obtained satisfactorily.

  In the OCT device 1 of this embodiment, the control unit 70 controls the drive unit 50 (adjuster) of the light beam diameter adjusting unit 22 in conjunction with the change in the relative position of the scanning unit 24 with respect to the objective optical system 27. Thereby, the beam diameter of the measurement light in the optical path between the OCT optical system 2 and the scanning unit 24 (that is, the optical scanner) is adjusted according to the position of the scanning unit 27. As a result, as described above, in this embodiment, the depth of focus corresponding to the photographing depth zone is set. As a result, for each tomographic image, a region where a good resolution can be obtained is set appropriately in the depth direction.

<Control action>
Hereinafter, the control operation of the OCT device 1 having the above-described configuration will be described in order using the flowchart shown in FIG. For example, in this embodiment, a case where an anterior ocular segment / fundus imaging mode for continuously imaging the anterior segment Ec and fundus Er of the eye E is set as an example. Accordingly, first, the control unit 70 captures the anterior eye portion Ec of the eye E and performs settings for acquiring the anterior eye OCT image data of the eye E. Note that an anterior ocular segment imaging mode for imaging the anterior ocular segment Ec of the eye E to be examined and a fundus imaging mode for imaging the fundus oculi Er of the eye E to be examined may be provided. In this case, the examiner may be able to switch the imaging mode.

  For example, the examiner instructs the subject to watch the fixation target of the fixation target projection unit 90. When the anterior segment of the eye E is detected by the anterior segment imaging optical system (not shown), the anterior segment observation image 60 (see FIG. 6) is displayed on the monitor 75. On the anterior ocular segment observation image 60, alignment index images Ma to Mh described later appear. For example, in this state, the control unit 70 starts the automatic alignment by controlling the moving table 102 and the driving unit 106 and moving the measuring unit 103.

<Alignment of the eye to be examined with respect to the anterior segment (S1)>
For example, the control unit 70 performs alignment between the eye E and the optical axis L1 in the OCT optical system 2 based on a positional deviation between the eye E and an alignment reference position O1 described later (S1). FIG. 6 is a view showing an anterior ocular segment observation image 60 of the eye E to be examined. When detecting the alignment state between the eye E and the measurement optical system 20, the light source is turned on in the index projection optical system (not shown). As a result, the index images Ma to Mh are projected on the eye E in a ring shape. For example, the index images Ma and Me are at infinity, and the index images Mh and Mf are at finite distance. The control unit 70 detects the ring-shaped XY center coordinates (the cross mark shown in FIG. 6) in the index images Ma to Mh as the approximate corneal apex position K.

  For example, the alignment state of the eye E in the horizontal direction (X direction) and the vertical direction (Y direction) is determined using a preset alignment reference position O1 (see FIG. 7). For example, in the present embodiment, the alignment reference position O1 is set to a position where the substantially corneal apex position K of the eye E to be examined and the optical axis L1 coincide.

  FIG. 7 is a diagram for explaining the alignment control. For example, the control unit 70 obtains a deviation amount Δd between the detected substantially corneal apex position K of the eye E to be detected and the alignment reference position O1, so that the positional deviation in the XY direction of the optical axis L1 with respect to the eye E to be examined is determined. To detect. For example, when a position shift in the XY direction is detected with respect to the eye E, the control unit 70 adjusts the alignment in the X direction and the Y direction so that the deviation amount Δd becomes zero. That is, the control unit 70 adjusts the alignment in the X direction and the Y direction so that the substantially corneal apex position K of the eye E to be examined matches the alignment reference position O1.

  Further, for example, the alignment state of the eye E in the front-rear direction (Z direction) is determined using the index image described above. For example, in the present embodiment, when the eye E is in an appropriate position with respect to the OCT device 1 (that is, when there is no displacement in the Z direction with respect to the eye E), from the index image Ma at infinity. The image interval a up to Me and the image interval b from the finite index image Mh to Mf are set to have a certain ratio. For example, when the eye E is not in an appropriate position with respect to the OCT device 1 (that is, when there is a position shift in the Z direction with respect to the eye E), the image interval a from the index image Ma to Me at infinity Hardly changes, but the image interval b from the finite index image Mh to Mf changes. For example, the control unit 70 compares the image ratio (that is, a / b) between the image interval a between the index images Ma and Me at infinity and the image interval b between the index images Mh and Mf at finite distance, and this is constant. The alignment in the Z direction is adjusted so that the ratio becomes. For details of the above configuration, refer to JP-A-6-46999.

  For example, the control unit 70 drives the OCT optical system 2 with respect to the eye E in this way. When the alignment in the XYZ directions between the eye E and the OCT device 1 is adjusted, the control unit 70 determines that the alignment is completed and outputs an alignment completion signal.

<Optimization control at the time of photographing the anterior segment of the eye to be examined (S2)>
When the alignment completion signal is output, the control unit 70 issues a trigger signal for starting optimization and starts optimization (S2). For example, by performing optimization control, the anterior segment desired by the examiner can be observed with high sensitivity and high resolution. For example, the optimization control includes optical path length adjustment, focus adjustment, and polarization state adjustment (polarizer adjustment).

  For example, in this embodiment, optimization control is performed in the order of the first automatic optical path length adjustment, the focus adjustment, the second automatic optical path length adjustment, and the polarizer adjustment. For example, the control unit 70 sets the position of the reference mirror 34 to the initial position, and sets the refractive power of the lens 23a to 0D. When the initialization is completed, the control unit 70 moves the reference mirror 34 in one direction from the initial position in a predetermined step, and performs the first optical path length adjustment (first automatic optical path length adjustment). When the first optical path length adjustment is completed, the control unit 70 performs autofocus adjustment (focus adjustment) by changing the refractive power of the lens 23a so as to focus on the anterior segment of the eye E. When the autofocus adjustment is completed, the control unit 70 moves the reference mirror 34 in the direction of the optical axis L2 to adjust the second optical path length (second automatic optical path length adjustment) for readjustment of the optical path length (fine adjustment of the optical path length). )I do. When the second optical path length adjustment is completed, the control unit 70 adjusts the polarization state of the measurement light by moving the polarizer 31 to a position where the interference light can be strongly received (that is, a position where the polarization state of the measurement light and the reference light matches). To do.

<Acquisition of anterior segment 3D cross-sectional image data (S3)>
For example, the control unit 70 controls the OCT optical system 2 in the above-described state in which the alignment adjustment and the optimization control are performed, so that the first position corresponding to the first depth zone of the eye E (this example) Then, the anterior segment OCT image data of the subject eye E in the anterior segment Ec) of the subject eye E is acquired (S3). For example, the anterior segment OCT image data of the eye E may be anterior segment cross-sectional image data of the eye E. In this case, the anterior segment cross-sectional image data may be two-dimensional cross-sectional image data or three-dimensional cross-sectional image data. Further, the anterior segment cross-sectional image data may be front image data of the eye E to be integrated based on this. For example, in this embodiment, an anterior eye part three-dimensional cross-sectional image data of the eye E is acquired and used as an example.

  For example, the OCT device 1 may be configured to use a signal of an anterior ocular segment cross-sectional image (that is, a signal before being imaged) as the anterior ocular segment cross-sectional image data as described above. A configuration using a cross-sectional image may be used.

<Change of imaging region (S4)>
When the anterior segment 3D cross-sectional image data for the eye E is acquired, the control unit 70 automatically switches the measurement mode and changes the imaging region (S4). For example, in this embodiment, the setting for acquiring the anterior segment OCT image data of the eye E is automatically switched to the setting for acquiring the fundus OCT image data of the eye E. Thereby, the imaging region of the eye E can be changed from the anterior segment Ec to the fundus Er. For example, the control unit 70 performs alignment and optimization control with respect to the fundus Er of the eye E according to the change to the imaging region.

<Analysis of anterior segment 3D cross-sectional image data (S5)>
For example, the control unit 70 sets the scanning position of the measurement light in the OCT optical system 2 based on the acquired anterior ocular segment three-dimensional cross-sectional image data. For example, in this embodiment, the control unit 70 processes the anterior segment three-dimensional cross-sectional image data, thereby acquiring analysis information indicating the two-dimensional distribution of the turbidity unit 65 (see FIG. 8) (S5). For example, the control unit 70 sets the scanning position of the measurement light in the OCT optical system 2 based on the analysis information indicating the two-dimensional distribution of the turbidity 65 (see S6 described later). This will be described in detail below.

  For example, the control unit 70 may integrate the acquired anterior ocular segment three-dimensional cross-sectional image data in the depth direction and display the front image (En face image) data 62 of the anterior ocular segment Ec on the monitor 75. FIG. 8 is a view showing the front image data 62 of the anterior eye part. For example, in this embodiment, the anterior segment 3D cross-sectional image data of the eye E is acquired using OCT imaging. In the OCT imaging, a tomographic image is captured based on the reflectance of the measurement light in the eye E. When the eye E is turbid, the measurement light incident on the turbid portion 65 is reflected, so that the turbid portion 65 appears as a high-luminance (bright) image on the tomographic image. That is, on the front image data 62 of the anterior eye portion Ec, the turbidity portion 65 appears as an image with high luminance, and the portion that is not the turbidity portion (shaded portion in FIG. 8) appears as an image with low luminance (darkness).

  Note that, for example, when a transillumination image is captured based on the return light of the measurement light reflected from the fundus Er of the eye E (that is, when the transillumination is performed), the return light of the measurement light enters the turbid portion. Since it is blocked, the turbid portion appears as a shadow with low luminance on the transillumination image.

  For example, the control unit 70 acquires analysis information by performing analysis processing. In this embodiment, a case where a turbidity map is acquired as analysis information will be described as an example. First, for example, the control unit 70 performs binarization processing on the obtained front image data 62 of the anterior segment Ec. For example, in the present embodiment, the control unit 70 divides the front image data 62 of the anterior eye portion Ec for each pixel position, and detects a luminance value for each pixel position. For example, the control unit 70 sets a threshold value for binarizing the front image data 62 of the anterior segment Ec based on the detected luminance value. For example, such a threshold value may be set for each front image data of the anterior segment of the eye E to be examined. In this case, the threshold may be set using statistical information based on the average and standard deviation of luminance values at all pixel positions, or may be set using a discriminant analysis method. Further, for example, such a threshold value may be set in advance by an experiment or simulation, or may be configured to be arbitrarily set by the examiner.

  For example, the control unit 70 replaces each luminance value at a pixel position having a luminance value greater than or equal to the threshold and a pixel position having a luminance value less than the threshold. For example, in this case, the pixel position whose luminance value is greater than or equal to the threshold value may be replaced with the maximum luminance of 255 (white). Further, the pixel position whose luminance value is less than the threshold value may be replaced with the minimum 0 (black). Note that the luminance value is not limited to the present embodiment as long as it uses two different values with the threshold as a boundary.

  For example, when the binarization process is completed, the control unit 70 specifies the turbidity part 65 based on the result of the binarization process (binarization map). In this case, the control unit 70 may determine that the region in which the luminance value is replaced with 255 corresponds to the turbidity unit 65. Further, the control unit 70 may determine that the region in which the luminance value is replaced with 0 does not correspond to the turbid portion 65.

  For example, the control unit 70 may analyze the binarized map acquired as described above and acquire a turbidity map that can identify the position of the turbidity part 65 in the eye E to be examined. In the present embodiment, a case where a turbidity map that specifies the position of the turbidity portion 65 is acquired and the scanning position of the measurement light with respect to the eye E is set as an example is described. For example, FIG. 9 is an example of the turbidity map 63 that specifies the position of the turbidity portion 65. For example, the turbidity map 63 may indicate a turbidity portion 65 (inside the dotted line in FIG. 9) in the eye E and a region not corresponding to the turbidity portion 65 (outside the dotted line in FIG. 9).

  Next, the control unit 70 specifies the light transmission region 68 based on the acquired analysis information. For example, as described above, since the measurement light incident on the eye E is reflected by the turbidity portion 65, a region that does not correspond to the turbidity portion 65 is specified as the light transmission region 68 in this embodiment. That is, the control unit 70 specifies the pixel position where the luminance value is replaced with 0 in the binarization process as the light transmission region 68.

  The analysis information may be displayed on the monitor 75. In this case, for example, the examiner may observe the analysis information displayed on the monitor 75 and set the scanning position.

<Scanning position setting (S6)>
For example, when the optical axis L1 passing through the substantially corneal apex position K of the eye E is not the light transmission region 68, the control unit 70 performs OCT so that the measurement light in the OCT optical system 2 passes through the light transmission region 68. The scanning position of the measurement light in the optical system 2 is set (S6). For example, as the setting of the scanning position, the incident position of the measuring light may be set, the incident angle (scanning angle) of the measuring light may be set, or the scanning range of the measuring light may be set. . It should be noted that the setting of the incident position of the measurement light, the setting of the incident angle, and the setting of the scanning range may be combined depending on the position and size of the turbidity portion 65 in the eye E. Of course, the control unit 70 may be configured to perform at least one of setting the incident position of the measurement light, setting the incident angle, and setting the scanning range. For example, in the present embodiment, the case where the control unit 70 sets the scanning position of the measurement light by setting the incident position of the measurement light in the OCT optical system 2 with respect to the eye E will be described as an example.

  For example, the control unit 70 calculates the distance from the approximate corneal apex position K of the eye E to the edge 69 of the region that is not the light transmission region 68 (in other words, the region determined to correspond to the turbid portion 65). For example, the control unit 70 acquires the coordinate position (for example, pixel coordinate) of the edge 69 with respect to the meridian direction of all 360 degrees with the approximate corneal apex position K as the base point. For example, when the coordinate position is acquired from the approximately corneal apex position K in the meridian direction in increments of 1, the coordinate positions of 360 points can be obtained. Of course, the number of points for acquiring the coordinate position on the edge 69 may be any number, and is not limited to 360. For example, the control unit 70 compares the coordinate position of the substantially corneal apex position K with the coordinate position at each point on the edge, and obtains a difference between the X direction and the Y direction at these coordinate positions. Thereby, the distance from the approximate corneal apex position K of the eye E to each point on the edge can be calculated.

  Next, the control unit 70 selects the point P on the edge where the distance from the approximate corneal apex position K to the edge 69 is the shortest among the distances from the approximate corneal apex position K to each point on the edge. . Further, the control unit 70 sets a position away from the point P by a predetermined distance W on the extended line of the straight line connecting the corneal apex position K and the point P as the incident position 64 of the measurement light with respect to the eye E. For example, the predetermined distance W is a distance set to suppress measurement light in the OCT optical system 2 from interfering with the turbid portion 65. In other words, the predetermined distance W is a distance set so that the measurement light incident on the eye E does not hit the turbid portion 65. For example, the predetermined distance W may be set in advance by experiments or simulations.

  For example, when the measurement light incident position 64 on the eye E is set in this way, the control unit 70 sets the alignment reference position so that the measurement light is irradiated to the incident position 64.

<Alignment to the fundus of the eye to be examined (S7)>
For example, the alignment reference position O1 described above is set to a position where the substantially corneal apex position K of the eye E to be examined and the optical axis L1 in the OCT optical system 2 coincide. Therefore, for example, the control unit 70 sets the alignment reference position so that the measurement light is irradiated to the incident position 64 set as described above. For example, in the present embodiment, the control unit 70 changes the alignment reference position from the alignment reference position O1 to the alignment reference position O2.

  For example, when the alignment reference position O2 is set, the control unit 70 starts automatic alignment (S7). At this time, for example, the control unit 70 detects a displacement between the eye E and the alignment reference position. Further, the control unit 70 detects the alignment state between the eye E and the optical axis L1 in the OCT optical system 2 based on the detected positional deviation.

  For example, the control unit 70 controls the driving unit 106 to move the measurement unit 103 in the vertical direction with respect to the eye E. For example, the control unit 70 drives the moving table 102 to move the measuring unit 103 in the left-right direction with respect to the eye E. For example, in this embodiment, the actual distance for the length of one pixel is determined in advance. Therefore, the control unit 70 moves the measurement unit 103 in the X direction and the Y direction based on the difference in the X direction and the Y direction between the coordinate position of the substantially corneal apex position K and the coordinate position of the incident position 64 described above. Therefore, it can be converted into a movement amount. For example, the control unit 70 adjusts the alignment in the X direction and the Y direction so that the optical axis L1 in the OCT optical system 2 matches the alignment reference position O2.

  For example, the control unit 70 can adjust the alignment between the eye E to be examined and the OCT device 1 in this way, and can align the optical axis L1 of the OCT optical system 2 with the alignment reference position O2. That is, the position where the measurement light in the OCT optical system 2 passes through the eye E can be avoided from the turbid portion 65. Moreover, the control part 70 will output an alignment completion signal, if alignment is adjusted in this way.

<Optimization control at the time of fundus photographing of the eye to be examined (S8)>
For example, when the alignment completion signal is output, the optimization is performed in the order of the first automatic optical path length adjustment, the focus adjustment, the second automatic optical path length adjustment, and the polarizer adjustment in the same manner as the optimization control described above (S8). . As a result, the fundus site desired by the examiner can be observed with high sensitivity and high resolution.

<Acquisition of fundus OCT image data (S9)>
For example, the control unit 70 controls the OCT optical system 2 at the scanning position set as described above, so that the second position corresponding to the second depth zone of the eye E (in this example, the eye to be examined). The fundus OCT image data of the eye E to be examined in the fundus Er of E) is acquired (S9). For example, the fundus OCT image data of the eye E may be tomographic image data of the eye E, motion contrast data, or polarization characteristic data. For example, in this embodiment, tomographic image data on the fundus Er of the eye E is acquired. Of course, such fundus OCT image data may be configured to use a signal before being imaged, or may be configured to use a fundus OCT image.

  As described above, for example, the ophthalmic imaging apparatus according to the present embodiment sets the scanning position of the measurement light based on the acquisition unit that acquires the anterior segment cross-sectional image data of the eye to be examined and the anterior segment cross-sectional image data. Scanning position setting means, and control means for acquiring fundus OCT image data of the eye to be examined at the scanning position set by the scanning position setting means. Thereby, the examiner can efficiently acquire the respective image data in the anterior eye portion and the fundus of the eye to be examined.

  Further, for example, the ophthalmologic photographing apparatus according to the present embodiment acquires analysis information indicating the two-dimensional distribution of the turbid portion by processing the anterior segment cross-sectional image data, and measures light in the OCT optical system based on the analysis information. Set the scanning position. As a result, the examiner can easily determine the position of the turbid portion generated in the eye to be examined. Further, the examiner can easily set the scanning position of the measurement light.

  Further, for example, the ophthalmologic photographing apparatus according to the present embodiment specifies a light transmission region based on the analysis information, and the measurement light scanning position in the OCT optical system so that the measurement light in the OCT optical system passes through the light transmission region. Set. For this reason, the examiner can easily set the scanning position of the measurement light so as to avoid the turbid portion generated in the eye to be examined.

  Further, for example, the ophthalmologic photographing apparatus according to the present embodiment can set the scanning position of the measurement light by setting the incident position of the measurement light on the eye to be examined in the OCT optical system. Thus, the examiner can set the incident position of the measurement light to the eye so as to avoid the cloudy part of the eye, and can efficiently perform fundus imaging.

  In addition, for example, the ophthalmologic photographing apparatus according to the present embodiment includes an alignment detection unit that detects the alignment state between the eye to be examined and the optical axis of the OCT optical system based on the positional deviation between the eye to be examined and the alignment reference position. Thereby, the alignment reference position can be set so that the measurement light is irradiated to the incident position set by the scanning position setting means. Therefore, the examiner can make the measurement light incident on the eye to be examined at a more accurate position.

  Further, for example, the ophthalmologic photographing apparatus according to the present embodiment includes a driving unit that drives the OCT optical system with respect to the eye to be examined. In addition, the ophthalmic imaging apparatus according to the present embodiment automatically detects the OCT optical system for the eye to be examined so that the optical axis of the OCT optical system is positioned within the allowable range of the alignment reference position based on the detection result of the alignment detection unit. Alignment control means for performing alignment is provided. Thereby, alignment is performed with high accuracy, and the examiner can efficiently align the eye to be examined and the OCT optical system.

  Further, for example, the ophthalmologic imaging apparatus according to the present embodiment acquires OCT image data at the first position corresponding to the first depth zone of the eye to be examined and the second position corresponding to the second depth zone of the eye to be examined. be able to. Further, for example, the ophthalmologic imaging apparatus according to the present embodiment acquires anterior ocular segment OCT image data of the eye to be examined at the first position as the anterior segment cross-sectional image data, controls the OCT optical system, and controls the OCT optical system at the second position. Fundus OCT image data of the eye to be examined can be acquired. Thereby, a new member, an attachment, etc. are not required, but the site | part from which a depth zone differs can be image | photographed easily.

  In addition, for example, the ophthalmologic imaging apparatus according to the present embodiment can acquire the fundus OCT image data of the eye to be examined by acquiring the anterior ocular segment OCT image data by the acquisition unit and then controlling the OCT optical system. As a result, the examiner can continuously take an image of the anterior eye portion and the fundus of the eye to be examined, and perform an efficient measurement.

  In addition, for example, the ophthalmologic photographing apparatus according to the present embodiment acquires anterior ocular segment cross-sectional image data as the anterior ocular segment cross-sectional image data of the eye to be examined. For this reason, the position of the cloudy part in the eye to be examined can be specified not only in the XY direction but also in the Z direction (depth direction). Therefore, the examiner can acquire the fundus OCT image data of the eye to be examined with high accuracy.

<Transformation example>
In the present embodiment, the configuration in which the OCT device 1 is used to acquire the anterior segment cross-sectional image data of the eye E is described as an example, but the present invention is not limited to this. For example, the anterior segment cross-sectional image data of the eye E may be acquired using a technique other than optical interference. For example, in this case, the anterior segment cross-sectional image data may be acquired by an imaging device such as an SLO (Scanning Laser Ophthalmoscope) or a Shine peak camera.

  In the present embodiment, the case where the scanning position of the measurement light is determined based on the anterior segment cross-sectional image data acquired by the ophthalmologic photographing apparatus 1 is described as an example, but the present invention is not limited to this. For example, the scanning position of the measurement light may be determined based on the transillumination image data. In this case, the ophthalmologic imaging apparatus 1 according to the present embodiment may be configured to be able to acquire transillumination image data of the eye E. In this case, the configuration may be such that the transillumination data of the eye E is acquired using another device. For example, as another device, a device that can objectively measure the eye refractive power of the eye E by receiving reflected light of a light beam projected onto the fundus Er of the eye E is also used. Good.

  In the present embodiment, the configuration in which the optical axis L1 in the OCT optical system 2 coincides with the alignment reference positions O1 and O2 has been described as an example, but the present invention is not limited to this. In the present embodiment, a predetermined region in the XY directions centering on the alignment reference positions O1 and O2 may be set as an alignment allowable range for determining whether or not alignment is appropriate. Of course, the alignment allowable range may also be set for a predetermined region in the Z direction centered on the alignment reference position. For example, the control unit 70 performs automatic alignment of the OCT optical system 2 with respect to the eye E so that the optical axis L1 of the OCT optical system 2 is positioned within the allowable range of the alignment reference position.

  FIG. 10 is a diagram for explaining the alignment allowable range. For example, in the alignment reference position O1, a predetermined area centered on the alignment reference position O1 is set as an alignment allowable range A1 for determining the suitability of alignment. For example, the control unit 70 adjusts the alignment in the X direction and the Y direction so that the passing position of the optical axis L1 in the OCT optical system 2 falls within the alignment allowable range A1. For example, in FIG. 10, since the actual position O1 ′ through which the optical axis L1 passes with respect to the eye E is within the alignment allowable range A1, the control unit 70 determines that the alignment is completed.

  Similarly, for example, with respect to the alignment reference position O2, the alignment allowable range A2 may be set in a predetermined region centered on the alignment reference position O2. For example, the control unit 70 adjusts the alignment in the X direction and the Y direction so that the passing position of the optical axis L1 in the OCT optical system 2 falls within the alignment allowable range A2. For example, in FIG. 10, since the actual position O2 ′ through which the optical axis L1 passes with respect to the eye E is within the alignment allowable range A2, the control unit 70 determines that the alignment is completed.

  Although description is omitted in the present embodiment, the position of the eye E to be inspected may be shifted between the anterior segment imaging and the fundus imaging. In this state, even if the measurement light is applied to the incident position 64 set by analyzing the anterior segment cross-sectional image data, the measurement light cannot be incident on a desired fundus site, and good fundus OCT image data is obtained. Can not get. For example, at this time, the control unit 70 may detect the positional deviation of the eye E and correct it.

  FIG. 11 is a diagram for explaining correction of positional deviation in the eye E. FIG. For example, FIG. 11 shows a state in which the eye E has moved in the X direction after photographing the anterior segment. Accordingly, the turbidity 65 of the eye E moves from the position indicated by the dotted line to the position indicated by the solid line. In the following, correction of misalignment in the X direction will be described. However, if misalignment occurs in the Y direction and the Z direction, the misalignment may be corrected in the same manner as in the X direction.

  For example, the control unit 70 detects misalignment between the position of the eye E during photographing of the anterior segment and the position of the eye E before photographing of the fundus. The term “before fundus imaging” in this embodiment may be the timing at which the setting is automatically switched to change the imaging region from the anterior segment Ec of the eye E to the fundus Er. That is, the control unit 70 controls the anterior ocular segment imaging optical system (not shown) using the change of setting as a trigger signal, and detects the anterior ocular segment of the eye E to be examined. Further, for example, the term “before fundus photographing in the present embodiment” may be the timing immediately before photographing the fundus Er of the eye E. In this case, the control unit 70 may detect the anterior segment of the eye E after alignment and optimization control with respect to the fundus Er. For example, the control unit 70 may detect the anterior segment of the eye E at a timing when an imaging switch (not shown) for performing fundus imaging included in the operation unit 74 is selected by the examiner. For example, the control unit 70 detects the approximate corneal apex position K ′ from the anterior eye portion of the eye E detected at such timing.

  For example, the control unit 70 detects a displacement between the detected approximate corneal apex position K ′ and the approximate corneal apex position K detected at the time of photographing the anterior segment as the correction amount ΔD. For example, the control unit 70 changes the incident position 64 of the measurement light based on the detected correction amount ΔD. For example, in the present embodiment, the incident position 64 of the measurement light is set to the incident position 64 ′ moved by the same distance as the correction amount ΔD. Accordingly, it is possible to correct the positional deviation of the eye E during the anterior segment imaging and the fundus imaging.

  For example, the ophthalmologic photographing apparatus according to the present embodiment detects a positional shift of the eye E during photographing of the anterior segment and photographing of the fundus, and corrects the measurement light accurately to the desired fundus position by correcting in this way. This makes it possible to acquire good fundus OCT image data.

  Note that the correction of the positional deviation is not limited to the application of an apparatus for setting the scanning position of the measurement light based on the analysis information of the turbidity portion 65 and photographing the fundus oculi Er as in the present embodiment. For example, when the imaging part is switched from the anterior segment Ec of the eye E to the fundus Er, if the position of the eye E is shifted, the correction may be performed as described above. For example, with such a configuration, the positional shift of the eye E during the anterior segment imaging and fundus imaging of the eye E is automatically corrected, so that the examiner can proceed with imaging smoothly. it can.

  In addition, you may implement correction | amendment of the position shift in the to-be-tested eye E in tracking control (tracking) mentioned later. In this case, the anterior segment of the eye E is always detected, and the correction amount ΔD between the approximate corneal apex position K detected at the time of imaging the anterior segment and the approximate corneal apex position K ′ shifted as the eye E moves. Is always calculated by the control unit 70. Further, the incident position 64 ′ of the measurement light is sequentially changed by the control unit 70. The anterior segment of the eye E thus detected may be used only for analysis processing by the control unit 70, or may be configured to be displayed on the monitor 75 as the anterior segment observation image 60.

  In the above description, the configuration in which the correction amount ΔD is detected and corrected is taken as an example. However, if the correction amount ΔD is small, the positional deviation of the eye E may not be corrected. For example, at this time, an allowable range may be set for the correction amount ΔD. Such an allowable range may be calculated in advance by simulation or experiment. For example, the control unit 70 determines whether the detected correction amount ΔD exceeds the allowable range or falls within the allowable range, and determines whether to correct the positional deviation of the eye E based on the result. The structure to determine may be sufficient.

  In the present embodiment, the configuration in which the alignment reference positions O1 and O2 are set so as to adjust all of the X direction, the Y direction, and the Z direction has been described as an example, but the present invention is not limited to this. Such an alignment reference position may be set with respect to at least one of the XYZ directions. Similarly, in this embodiment, the alignment allowable ranges A1 and A2 are set so as to adjust all of the X direction, the Y direction, and the Z direction. However, such an alignment reference range is also in at least one of the XYZ directions. You may set it.

  In the present embodiment, the configuration using the approximate corneal apex position K in the eye E when detecting the positional deviation between the eye E and the alignment reference position is described as an example, but the present invention is not limited to this. Of course, the position of the corneal apex of the eye E to be examined may be used for detecting the displacement. Further, for example, the position of the pupil of the eye E may be used for detecting the position shift. In this case, the control unit 70 may detect the pupil position in the eye E from the front image of the anterior segment imaged by an anterior segment imaging optical system (not shown). At this time, the control unit 70 may be configured to detect a positional deviation from the alignment reference position using the detected pupil position, and to adjust the incident light to be irradiated with the measurement light based on this.

  In the present embodiment, the configuration using the substantially corneal apex position K has been described as an example in the case of detecting the positional deviation of the eye E during the anterior segment imaging and the fundus imaging. The pupil position may be detected.

  In the present embodiment, the configuration in which the control unit 70 performs automatic alignment has been described as an example, but the present invention is not limited to this. For example, alignment may be performed manually by an examiner. For example, the measurement unit 103 can move in the left-right direction, the up-down direction, and the front-back direction by operating the joystick 104 or the like. When the alignment is performed manually, the position through which the optical axis L1 of the measurement light passes and the alignment reference position may be displayed. Thus, the examiner can operate the joystick 104 while looking at the monitor 75 to match the optical axis L1 of the measurement light in the OCT optical system 2 with the alignment reference position. Alternatively, the optical axis L1 of the measurement light in the OCT optical system 2 can be kept within the alignment allowable range.

  In the present embodiment, the configuration in which the incident position of the measurement light with respect to the eye E is changed and the scan position of the measurement light is set by moving the OCT device 1 has been described as an example, but the present invention is not limited thereto. Not. For example, the incident position of the measurement light may be changed by moving an optical member included in the OCT optical system 2 or may be changed by inserting or removing the optical member in the optical path of the OCT optical system 2. . For example, when moving an optical member, the structure which enables the lens 22a and the lens 22b with which the light beam diameter adjustment part 22 is provided to move to the left-right direction and the front-back direction is mentioned. Moreover, the structure which enables the dichroic mirror 26 to move to an up-down direction is mentioned. For example, when the optical member is inserted / removed, a configuration in which a prism, a mirror, or the like can be inserted / removed on the optical axis L1 can be used.

  In the present embodiment, the configuration in which the incident position of the measurement light with respect to the eye E is changed by moving the OCT device 1 has been described as an example, but the present invention is not limited to this. For example, the incident position of the measurement light with respect to the eye E may be changed by changing the position of the fixation target in the fixation target projection unit 90. For example, if the position of the fixation target is shifted, the line of sight of the subject moves and the eye E rotates, so that the measurement light can be incident while avoiding the turbid portion generated in the eye E. is there.

  In the present embodiment, the configuration in which the scanning position of the measurement light is automatically set has been described as an example, but the present invention is not limited to this. For example, the scan position of the measurement light may be manually set by the examiner. For example, in this case, the control unit 70 may display a front image obtained by integrating the anterior segment 3D cross-sectional image data on the monitor 75. Of course, the analysis information when the binarization process is performed on the front image data 62 of the anterior eye part in the eye E to be examined and the two-dimensional distribution specifying the position of the turbid part 65 are displayed on the monitor 75 as a map. Also good. For example, the examiner looks at the monitor 75 to determine where the turbidity portion 65 is in the eye E, and operates the operation unit 74 to select a scanning position on the front image. The control unit 70 detects the coordinate position at the scanning position on the selected front screen, and moves the OCT device 1 based on the detected coordinate position. For example, the scanning position of the measurement light may be set to an arbitrary position in this way.

  In the present embodiment, the first position corresponding to the first depth zone of the eye E (in this embodiment, the anterior eye portion Ec of the eye E) and the second depth zone of the eye E to be examined. The second position (in this embodiment, the fundus Er of the eye E to be examined) has been described as an example of the configuration for continuously photographing, but the present invention is not limited to this. For example, the first depth zone and the second depth zone of the eye E may be photographed simultaneously. That is, the anterior eye portion Ec and the fundus oculi Er in the eye E may be photographed simultaneously. For example, in this case, the optical path of the reference optical system 30 may be branched using a half mirror or the like, and a reference mirror may be disposed on each of them. For example, one of the reference mirrors is disposed at a position that is equal to the optical path length in the return light of the measurement light from the anterior segment Ec. Further, for example, the other reference mirror is disposed at a position equal to the optical path length in the return light of the measurement light from the fundus Er. Thereby, the interference signal in which the return light from the anterior eye Ec interferes with the reference light and the interference signal in which the return light from the fundus Er interferes with the reference light can be simultaneously acquired by the detector 40. It becomes like this.

  In the present embodiment, the configuration in which the anterior ocular segment three-dimensional cross-sectional image data is acquired after the alignment between the eye E to be examined and the alignment reference position O1 has been described as an example, but is not limited thereto. For example, the anterior ocular segment three-dimensional cross-sectional image data may be acquired in real time, and the scanning position of the measurement light may be sequentially set based on the acquired data. In this case, even after the alignment with respect to the eye E is completed, the control unit 70 performs tracking control (tracking) that detects the alignment deviation in the XYZ directions as needed and always detects the movement of the eye E. Thereby, the anterior segment 3D cross-sectional image data can be repeatedly acquired in real time. Further, for example, the control unit 70 may process the data every time the anterior segment three-dimensional cross-sectional image data is acquired, and always detect the turbid portion 65 in the eye E to be examined. Thereby, even when the eye E moves, the scanning position of the measurement light for acquiring the fundus OCT image data can be sequentially set at a position where the turbid portion 65 can be avoided. For example, the fundus OCT image data acquisition position may be displayed on the real-time anterior segment three-dimensional cross-sectional image data.

  For example, as described above, the ophthalmologic imaging apparatus according to the present embodiment acquires the anterior segment cross-sectional image data of the eye to be examined in real time, and the measurement light scanning position based on the anterior segment cross-sectional image data acquired in real time. Can be set sequentially. As a result, the scanning position is always corrected so that the measurement light is incident on the imaging region desired by the examiner. Therefore, the examiner can acquire the fundus OCT image data more accurately.

  In the present embodiment, an example is described in which the anterior segment Ec is captured as the first position of the eye E and the fundus oculi Er is captured as the second position of the eye E, and the respective OCT image data is acquired. Although described, it is not limited to this. For example, the ophthalmologic imaging apparatus 1 according to the present embodiment may acquire OCT image data in different depth zones in the anterior segment Ec of the eye E to be examined. For example, in this case, the first position may be taken from the front of the cornea of the eye E to the front of the crystalline lens. Further, for example, in this case, the rear surface of the crystalline lens of the eye E may be photographed as the second position. Of course, when turbidity is detected in the cornea of the eye E or the front surface of the crystalline lens, the scanning position of the measuring light may be determined using the analysis information of the turbid portion, and the rear surface of the crystalline lens may be photographed. Thus, the examiner can acquire more detailed anterior segment OCT image data of the eye E to be examined.

DESCRIPTION OF SYMBOLS 1 Ophthalmic imaging device 11 Light source 15 Divider 20 Measurement optical system 22 Light beam diameter adjustment part 23 Condensing position variable optical system 24 Scan part 27 Objective optical system 30 Reference optical system 40 Detector 50 Drive part 70 Control part 103 Measurement part

Claims (11)

An ophthalmologic imaging apparatus that has an OCT optical system that detects an OCT signal generated by measurement light and reference light irradiated on a subject's eye, and acquires OCT image data of the subject's eye by processing the OCT signal,
An acquisition means for acquiring the anterior segment cross-sectional image data of the eye to be examined;
Scanning position setting means for setting a scanning position of the measurement light based on the anterior segment cross-sectional image data acquired by the acquisition means;
Control means for controlling the OCT optical system and acquiring fundus OCT image data of the eye to be examined at the scanning position set by the scanning position setting means;
An ophthalmologic photographing apparatus comprising: The ophthalmologic photographing apparatus according to claim 1.
The scanning position setting means acquires the analysis information indicating the two-dimensional distribution of the turbid portion by processing the anterior segment cross-sectional image data, and based on the analysis information, the measurement light of the OCT optical system An ophthalmologic photographing apparatus characterized by setting a scanning position. The ophthalmologic photographing apparatus according to claim 2,
The scanning position setting means specifies a light transmission region based on the analysis information and scans the measurement light in the OCT optical system so that the measurement light in the OCT optical system passes through the light transmission region. An ophthalmologic photographing apparatus characterized by setting the above. In the ophthalmologic photographing apparatus according to any one of claims 1 to 3,
The ophthalmologic imaging apparatus, wherein the scanning position setting means sets a scanning position of the measurement light by setting an incident position of the measurement light on the eye to be examined in the OCT optical system. The ophthalmologic photographing apparatus according to claim 4,
Alignment detection means for detecting an alignment state between the eye to be examined and the optical axis of the OCT optical system based on a positional shift between the eye to be examined and an alignment reference position;
The ophthalmic imaging apparatus, wherein the alignment detection unit sets the alignment reference position so that the measurement light is irradiated to the incident position set by the scanning position setting unit. The ophthalmologic photographing apparatus according to claim 5,
Driving means for driving the OCT optical system with respect to the eye to be examined;
Based on the detection result of the alignment detection means, the drive means is driven so that the optical axis of the OCT optical system is positioned within an allowable range of the alignment reference position, and the OCT optical system for the eye to be examined Alignment control means for performing automatic alignment of
An ophthalmologic photographing apparatus comprising: In the ophthalmologic photographing apparatus according to any one of claims 1 to 6,
The OCT optical system includes an OCT image at a first position corresponding to a first depth zone of the eye to be examined and a second position corresponding to the second depth zone different from the first depth zone of the eye to be examined. An OCT optical system capable of acquiring data,
The acquisition means controls the OCT optical system as the anterior segment cross-sectional image data to acquire the anterior segment OCT image data of the eye to be examined at the first position;
The ophthalmologic imaging apparatus characterized in that the control means controls the OCT optical system to acquire the fundus OCT image data of the eye to be examined at the second position. The ophthalmologic photographing apparatus according to claim 7,
The control means, after acquiring the anterior segment OCT image data by the acquisition means,
An ophthalmologic imaging apparatus that controls the OCT optical system to acquire the fundus OCT image data of the eye to be examined at the second position. In the ophthalmologic photographing apparatus according to any one of claims 1 to 8,
The acquisition means acquires the anterior segment cross-sectional image data of the eye to be examined in real time,
The ophthalmic imaging apparatus, wherein the scanning position setting means sequentially sets the scanning position of the measurement light based on the anterior segment cross-sectional image data acquired in real time by the acquisition means. In the ophthalmologic photographing apparatus according to any one of claims 1 to 9,
The acquisition unit acquires an anterior ocular segment three-dimensional cross-sectional image data as the anterior ocular segment cross-sectional image data of the eye to be examined. An ophthalmologic imaging program used in an ophthalmologic imaging apparatus that has an OCT optical system that detects an OCT signal generated by measurement light and reference light emitted to an eye to be examined, and acquires OCT image data of the eye to be examined by processing the OCT signal And when executed by the processor of the ophthalmic imaging device,
An acquisition step of acquiring the anterior segment cross-sectional image data of the eye to be examined;
A scanning position setting step for setting a scanning position of the measurement light based on the anterior segment cross-sectional image data acquired by the acquisition step;
A control step of controlling the OCT optical system and acquiring fundus OCT image data of the eye to be examined at the scanning position set by the scanning position setting step;
Is executed by the ophthalmologic photographing apparatus.