Ophthalmic imaging equipment

Abstract

To provide an ophthalmologic imaging apparatus having improved operability in imaging.SOLUTION: A fundus imaging apparatus comprises an SLO optical system / OCT optical system, and a control section. The imaging apparatus changes over an objective optical system based on an operation of an examiner so as to at least change a field angle of the SLO optical system / OCT optical system between a first field angle and a second field angle. The control section selects any of a plurality of imaging operations and outputs, to an examiner, guide information for guiding an operation for changing the field angle of the SLO optical system / OCT optical system according to an imaging operation to be selected.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to an ophthalmic imaging apparatus that captures an image of a subject's eye. [Background technology]

[0002] In the field of ophthalmology equipment as a whole, automation of equipment operation is progressing, but on the other hand, in the field of equipment for highly specialized ophthalmic facilities, the importance of accuracy in examination results is emphasized, so equipment that is assumed to be operated by highly specialized examiners is still strongly supported.

[0003] For example, in recent years, wide-angle fundus photography has been attracting attention, and an example of an apparatus for wide-angle fundus photography is disclosed in Patent Document 1, in which the angle of view of the photographing optical system is switched by manually attaching and detaching a lens attachment between the photographing optical system of the device body and the subject's eye.

[0004] In addition, with the device disclosed in Patent Document 1, even when capturing a frontal image of the fundus, one of a number of capture operations, such as color capture, fluorescent contrast capture, and autofluorescence capture, can be selected and used, and further, tomographic images (OCT images) can also be captured. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-150424 A Summary of the Invention [Problem to be solved by the invention]

[0006] Because a single device is capable of performing a variety of imaging operations, it may become difficult for the examiner to smoothly perform operations according to the imaging operations.

[0007] In particular, in a device capable of switching the angle of view as in Patent Document 1, at least an operation for switching the angle of view is required, and it is conceivable that there may be a need to adjust the alignment state, fixation state, etc. for each angle of view setting. The inventors of the present application have examined room for improvement in the operability of such a device capable of switching the angle of view.

[0008] The present disclosure has been made in consideration of the problems in the conventional technology, and has an object to provide an ophthalmologic imaging apparatus with improved operability during imaging. [Means for solving the problem]

[0009] An ophthalmic imaging apparatus according to a first aspect of the present disclosure includes an imaging optical system that captures an ophthalmic image of a test eye via an objective optical system, and an angle-of-view changing unit that changes an angle of view of the imaging optical system at least between a first angle of view and a second angle of view larger than the first angle of view by switching the objective optical system based on an operation of an examiner; The method includes at least a combination imaging in which an operation of capturing a fluorescent contrast image at the first angle of view and an operation of capturing a fluorescent contrast image at the second angle of view are performed consecutively. A selection means for selecting one of a plurality of photographing operations; when the combination photographing is selected, at a timing between an operation of photographing the fluorescence contrast image using the first angle of view and an operation of photographing the fluorescence contrast image using the second angle of view, Guidance information for guiding the operation for changing the angle of view of the photographing optical system. , Inspection and a guidance means for outputting the guidance signal to the user. [Brief description of the drawings]

[0010] [Figure 1] 1 is an external view of an ophthalmologic photographing apparatus according to an embodiment. [Diagram 2] FIG. 1 illustrates an SLO optical system according to a first embodiment. [Diagram 3] This shows the state in which an attachment optical system is attached to the SLO optical system shown in FIG. [Figure 4] 4 is a flowchart showing the operation of the device of the first embodiment. [Diagram 5] FIG. 4 is a diagram for explaining a setting operation of a shooting range in the first embodiment. [Figure 6] FIG. 13 is a diagram illustrating an OCT optical system according to a second embodiment. [Figure 7]FIG. 11 is a diagram for explaining a setting operation of a shooting range in the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] <Summary> An embodiment of an ophthalmic imaging apparatus according to the present disclosure will be described. The items grouped in <> below can be used independently or in conjunction with each other.

[0012] The ophthalmic imaging apparatus of the present embodiment images an eye to be examined. For example, the ophthalmic imaging apparatus may be any of an OCT apparatus (e.g., an OCT apparatus) having an optical coherence tomography (OCT) configuration, a scanning laser ophthalmoscope (SLO) apparatus having an SLO configuration, a fundus camera, etc. Of course, the ophthalmic imaging apparatus may be a device that combines two or more of these.

[0013] The ophthalmologic imaging device of the present embodiment includes at least an imaging optical system, an angle-of-view changing unit (e.g., an angle-of-view changing mechanism), a selection unit, and a guidance unit. Among these, the selection unit and the guidance unit may be shared by a control unit of the device.

[0014] <Photographic optical system> The ophthalmologic image is captured by the imaging optical system through the objective optical system. The imaging optical system may include a plurality of optical systems provided for each modality. For example, the imaging optical system may be a combination of a front image capturing optical system (e.g., either an SLO optical system or a fundus camera optical system) and an OCT optical system.

[0015] An ophthalmic image is a photographed image of tissue of a subject's eye. The ophthalmic image may be an image of the anterior segment of the eye or an image of the fundus of the eye. The ophthalmic image may also be a front image or a tomographic image (cross-sectional image). The ophthalmic image may also be a fluorescent contrast image.

[0016] <Angle of view change section> The angle of view changer changes the angle of view of the photographing optical system at least between a first angle of view and a second angle of view by switching the objective optical system based on the examiner's operation. In this embodiment, the "angle of view of the photographing optical system" refers to the maximum photographing range of an ophthalmic image defined at least by the objective optical system. The second angle of view is larger than the first angle of view. For example, the insertion / removal or replacement of an optical element in the objective optical system, switching of the arrangement of the optical element, etc. may be performed based on the examiner's operation, thereby changing the angle of view between the first angle of view and the second angle of view.

[0017] <Selection section> The selection unit is used to select one of a plurality of imaging operations. The selectable imaging operations may differ from each other in, for example, modality, imaging position (imaging pattern), and / or angle of view of the imaging optical system.

[0018] <Guidance section> The guidance unit outputs guidance information to the examiner according to the photographing operation selected by the selection unit. The guidance information includes information that guides the examiner to perform an operation to change the angle of view of the photographing optical system. This allows the examiner to smoothly perform an operation to change the angle of view according to the photographing operation, since the guidance information prompts the examiner to perform an operation to change the angle of view according to the photographing operation.

[0019] The guidance information may simply indicate that a field angle switching operation is required, or may specifically explain the contents of the setting operation. The guidance information may be output in the form of a voice announcement, or may be output via a monitor in the form of an image or text.

[0020] <Combination shooting> The selection unit may be capable of selecting combination imaging in which a plurality of imaging operations in which at least one of modality, imaging position (imaging pattern), and angle of view of the imaging optical system is different from one another is continuously performed.

[0021] When combination photography is selected, the guidance unit may output guidance information to the examiner at least at a timing between the photographing operation at the first angle of view and the photographing operation at the second angle of view. In combination photography in which the photographing operation at the first angle of view and the photographing operation at the second angle of view are performed consecutively, the guidance information prompts the examiner to perform an operation to change the angle of view at an appropriate timing between the photographing operations. Therefore, combination photography can be easily performed smoothly.

[0022] In addition, in the combination imaging, the fluorescent contrast image of the subject's eye may be captured at each of the first and second angles of view. In the fluorescent contrast imaging, the location where light and dark occurs changes over time due to the circulation of the fluorescent contrast agent. In other words, the time phase changes over time. In the fluorescent contrast imaging, the contrast agent and the mydriatic agent are administered to the subject, which places a heavy burden on the subject, so that re-imaging cannot be easily performed. When the first and second angles of view are captured consecutively, if it takes time to switch the angles of view, a valuable opportunity to capture a desired contrast state may be missed. In contrast, in the present embodiment, while the fluorescent contrast images are captured at each of the first and second angles of view, guidance information is output to the examiner, making it easier to appropriately capture fluorescent contrast images at the desired contrast state at each of the first and second angles of view.

[0023] <Output of second guidance information> It is possible that the alignment tolerance of the device and the presentation position of the fixation target, etc., cannot be maintained before and after the angle of view of the imaging optical system is changed, and adjustment operations may be required to make different adjustments for each angle of view.

[0024] In contrast to this, in the present embodiment, the guidance unit may further output second guidance information to the examiner. The second guidance information includes information guiding the examiner to perform an adjustment operation for adjusting the positional relationship between the subject's eye and the photographing optical system. When it is detected in the second guidance information that the positional relationship has been adjusted to the initial positional relationship, the output of the guidance information may be terminated.

[0025] The second guidance information may guide alignment adjustment at least in the working distance direction, or may guide swing and tilt of the imaging optical system. For example, the second guidance information may graphically indicate the direction of operation input to reach the alignment target position or the moving direction of the device by using an arrow indicating the direction, a mark indicating the target position, or the like. Also, for example, the second guidance information may guide a change in the presentation position of the fixation light.

[0026] For example, the second guide information may be displayed together with the observation image. In this state, regardless of whether the positional relationship is actually adjusted based on the second guide information, the photographing may be performed based on an operation input for starting the photographing. That is, the fundus image may be photographed at the stage when the examiner judges that an appropriate image can be obtained based on the observation image.

[0027] When the second guide information is displayed together with the observation image, for example, the second guide information may be superimposed on the observation image.

[0028] The second guidance information may be further output to the examiner at least at a timing between the shooting operation at the first angle of view and the shooting operation at the second angle of view in combination shooting in which the shooting operation at the first angle of view and the shooting operation at the second angle of view are performed consecutively. Even if it becomes necessary to adjust the positional relationship between the subject's eye and the photographing optical system again due to switching of the objective optical system, the examiner can be appropriately prompted to adjust the positional relationship based on the second guidance information. The second guidance information may be output, for example, at a stage where the completion of the operation for changing the angle of view is confirmed. This allows even an inexperienced examiner to perform the setting operations of switching the angle of view and adjusting the positional relationship between the subject's eye and the photographing optical system in an appropriate order.

[0029] <Change the guidance information according to the input operation of the shooting range> The ophthalmic imaging apparatus of the present embodiment may further include a reception unit. The reception unit receives an input operation of the imaging range desired by the examiner via a GUI. The reception unit may include a GUI that allows the imaging range to be input. The GUI may display a graphic that at least represents an imaging site to be imaged by the imaging optical system, and the imaging range may be input on the graphic. Here, the graphic that at least represents the imaging site may be an ophthalmic image of the subject's eye that has been imaged in advance, or may be a schematic diagram of the subject's eye that typically shows the subject's eye including the imaging site. The schematic diagram may be a schematic diagram of a fundus image, or an eyeball model that represents the structure of the eyeball, etc.

[0030] Here, the photographing optical system may be a scanning photographing optical system. The scanning photographing optical system photographs the subject's eye by scanning light with an optical scanner. In an apparatus equipped with such a photographing optical system, the angle of view of the photographing optical system defined by the objective optical system is the maximum value of the scanning range of the optical scanner (i.e., the maximum scanning range). In this case, the scanning range of the optical scanner is limited to a part of the maximum scanning range, so that a partial ophthalmic image can be photographed. For example, even when the photographing optical system is set to the second angle of view, an ophthalmic image can be captured in a narrower range than the second angle of view without the need to switch the angle of view of the photographing optical system. Although there is a trade-off between the image quality of an ophthalmic image (e.g., brightness, resolution, etc.) and the angle of view of the photographing optical system, in a situation where image quality is not required that much, capturing a partial ophthalmic image with the second angle of view is considered to be of some value from the viewpoint of workability in the examination. However, on the other hand, for example, a partial ophthalmic image captured with the photographing optical system set to the second angle of view is not suitable for detailed observation of a local area.

[0031] In contrast, in this embodiment, the guidance unit may determine whether the objective optical system should be switched based on the examiner's operation based on the input operation of the shooting range, and output guidance information according to the determination result. For example, when the size of the shooting range input via the reception unit is smaller than a threshold value in a state where the shooting optical system is set to the second angle of view, guidance information for guiding a change operation to the first angle of view may be output. Also, when the size of the shooting range input via the reception unit is larger than a threshold value, a partial fundus image may be captured for the second angle of view without outputting guidance information. In this case, the threshold value may be a value smaller than the first angle of view.

[0032] In addition, the positional relationship between the subject's eye and the photographing optical system may be adjusted or induced according to the photographing range specified by the input operation. The positional relationship may be adjusted or induced by a control unit of the device. The adjustment or induced positional relationship may be performed after the angle of view is switched between the first angle of view and the second angle of view.

[0033] When the positional relationship is adjusted according to the imaging range, an actuator for adjusting the alignment may be driven and controlled. Also, the presentation position of the fixation light may be automatically set according to the imaging range. When the positional relationship is guided according to the imaging range, information similar to the second guidance information described above may be output to the examiner.

[0034] In addition, the guidance unit determines whether or not the objective optical system should be switched based on the examiner's operation, and outputs guidance information according to the determination result, but this is not necessarily limited to this. Instead of the guidance information, a warning may be output that the current angle of view setting of the device is not appropriate.

[0035] After the guidance information or the warning is output, the examiner may input an operation to start imaging without changing the angle of view. In this case, imaging may be permitted within a predetermined imaging range.

[0036] In this embodiment, the examiner is required to operate the camera to switch the angle of view of the imaging optical system, but this is not necessarily limited to this, and the angle of view may be switched automatically. Also, in this embodiment, when the angle of view is switched, information informing the examiner of the switching may be output to the examiner.

[0037] In addition, according to the present embodiment, since the scanning range is limited and a partial ophthalmic image can be captured, it is possible that images are captured in the same capturing range between when the angle of view of the imaging optical system is set to the first angle of view and when the angle of view of the imaging optical system is set to the second angle of view. Since images captured in the same capturing range have different image quality depending on the angle of view setting of the imaging optical system, when the ophthalmic images are displayed, identification information indicating the angle of view setting of the device may be associated with the ophthalmic images, and the images may be distinguished in display and processing.

[0038] "Example" The ophthalmologic imaging apparatus according to this embodiment will be described based on an example of a fundus imaging apparatus.

[0039] <First Example> The fundus imaging device 1 (hereinafter referred to as the imaging device 1) according to the first embodiment has at least a front imaging optical system 200 (see FIGS. 2 and 3) that captures a front image of the fundus, and an arithmetic and control device (control unit) 70. The fundus imaging device 1 also has an operation unit.

[0040] The front photographing optical system in the first embodiment is a scanning laser opthalmoscope (SLO) optical system. In this embodiment, the SLO optical system 200 also serves as the fixation optical system. The fundus photographing device 1 may further include a memory 72, a monitor 75, an operation unit 80, etc. (see FIG. 4). The SLO optical system 200 two-dimensionally scans light on the fundus Er and receives return light from the fundus Er to obtain a front image of the fundus Er.

[0041] Figure 1 shows the schematic configuration of the imaging device 1. The imaging device 1 includes a base 5, a joystick 6, an operation unit 103, alignment adjustment units 7 and 8, a face support unit 9, etc. The imaging device 1 also has a control unit 70, a storage unit 71, an operation unit 75, and a monitor 80.

[0042] The front imaging optical system is housed in the imaging unit 4. In this embodiment, by driving the alignment adjustment units 7 and 8, the imaging unit 4 can move in the X, Y, and Z directions on the base 5. The alignment adjustment units 7 and 8 are driven automatically or in response to the operator's operation on the operation unit. In this embodiment, the alignment adjustment units 7 and 8 include an XYZ drive unit 7 and a swing-tilt unit 8. The XYZ drive unit 7 moves the imaging unit 4 three-dimensionally in the front-rear, up-down, and left-right directions with respect to the eye to be examined. The swing-tilt unit 8 swing-tilts the imaging unit 4 with the position of the eye to be examined as the approximate center.

[0043] The joystick 6 is one of the operation units. It is operated when manually adjusting the position of the imaging unit 4. It may also be provided with a release button.

[0044] The face support unit 9 supports the face of the subject.

[0045] <SLO optical system> Next, with reference to FIGS. 2 and 3, the SLO optical system 200 will be described. The SLO optical system 200 includes an illumination optical system 210 and a light receiving optical system 220. In the SLO optical system 200 of this embodiment, when the attachment optical system 330 (see FIG. 3) is attached, the angle of view is increased from the first angle of view to the second angle of view (FIG. 2 ⇒ FIG. 3). It is assumed that the first angle of view in this embodiment is about 60° and the second angle of view is about 100°.

[0046] First, with reference to FIG. 2, the optical system in the case of the first angle of view will be described. In this embodiment, when the attachment optical system 330 (see FIG. 3) is not attached, the first angle of view is set.

[0047] The irradiation optical system 210 includes a scanning unit 216 and an objective optical system 300. The objective optical system 300 includes at least one lens. As shown in FIG. 2, the irradiation optical system 210 further includes a laser light source 211, a mirror with a hole 213, a lens 214 (part of the diopter correction unit 240 in this embodiment), and a lens 215.

[0048] The laser light source 211 is a light source of the irradiation optical system 210. In this embodiment, the laser light from the laser light source 211 is used as the imaging light. The laser light source 211 in this embodiment can emit multiple colors of light simultaneously or selectively. As an example, in this embodiment, the laser light source 211 emits a total of four colors of light, including three colors in the visible range of blue, green, and red, and one color in the infrared range. The lights of each color may be emitted simultaneously in any combination. In this embodiment, the lights of each color emitted from the laser light source 211 are used to image the fundus. Note that a fundus image captured based on fundus reflected light may be referred to as a reflected image, and a fundus image captured based on fluorescence from a fluorescent substance present in the fundus Er may be referred to as a fluorescent image.

[0049] The reflection image may be any one or all of an infrared image, a color image, a red-free image, and a monochromatic visible image. The fluorescence image may be any one or all of a contrast fluorescence image and an autofluorescence image. The contrast fluorescence image may be an image based on the fluorescence of a contrast agent intravenously injected into the fundus Er, for example, an FA image (fluorescein angiography image) or an ICGA image (indocyanine green angiography image). The autofluorescence image may be an image based on the fluorescence of a fluorescent substance accumulated in the fundus Er, for example, an image based on the fluorescence of lipofuscin.

[0050] In this embodiment, the laser light from the laser light source 211 passes through an opening formed in the perforated mirror 213, passes through lenses 214 and 215, and then travels toward the scanning unit 216. The laser light reflected by the scanning unit 216 passes through the dichroic mirror 310 and the objective optical system 300, and is then irradiated onto the fundus Er of the subject's eye E. As a result, the laser light is reflected and scattered by the fundus Er, or excites fluorescent substances present in the fundus Er, causing fluorescence from the fundus. These lights (i.e., reflected and scattered light, fluorescence, etc.) are emitted from the pupil as light (return light) from the subject's eye accompanying the irradiation of the laser light.

[0051] The scanning unit 216 (also referred to as an "optical scanner") is a unit for scanning the fundus Er with the laser light emitted from the laser light source 211. In the following description, unless otherwise specified, the scanning unit 216 includes two optical scanners with different scanning directions of the laser light. That is, the scanning unit 216 includes an optical scanner 216a for main scanning (for example, for scanning in the X direction) and an optical scanner 216b for sub-scanning (for example, for scanning in the Y direction).

[0052] The objective optical system 300 is an objective optical system of the fundus imaging device 1. The objective optical system 300 is used to irradiate the laser light scanned by the scanning unit 216 to the subject's eye E and guide it to the fundus Er. For this purpose, the objective optical system 300 forms a turning point P around which the laser light passing through the scanning unit 216 turns. The turning point P is formed on the reference optical axis L1 of the irradiation optical system 210 and at a position optically conjugate with the scanning unit 216 with respect to the objective optical system 300. Note that in this disclosure, "conjugate" is not necessarily limited to a perfect conjugate relationship, but includes "approximate conjugate". That is, the "conjugate" in this disclosure also includes a case where the objective optical system 300 is positioned away from a perfect conjugate position within a range permitted in relation to the purpose of use of the fundus image (for example, observation, analysis, etc.). In this embodiment, the objective optical system 300 of the fundus imaging device 1 is realized only by a lens, but is not necessarily limited to this, and may be realized by a combination of a lens and a mirror.

[0053] The laser light that has passed through the scanning unit 216 passes through the objective optical system 300 and is irradiated onto the fundus Er via the rotation point P. Therefore, the laser light that has passed through the objective optical system 300 is rotated around the rotation point P as a center in accordance with the operation of the scanning unit 216. As a result, in this embodiment, the laser light is two-dimensionally scanned onto the fundus Er. The laser light irradiated onto the fundus Er is focused at a focusing position (for example, the retinal surface).

[0054] Next, the light receiving optical system 220 will be described. The light receiving optical system 220 has one or more light receiving elements. For example, as shown in Fig. 2, the light receiving optical system 220 may have multiple light receiving elements 225, 227, and 229. In this case, light from the fundus Er due to the laser light irradiated by the irradiation optical system 210 is received by at least one of the light receiving elements 225, 227, and 229.

[0055] 2, the light receiving optical system 220 in this embodiment may share each member arranged from the objective optical system 300 to the perforated mirror 213 with the irradiation optical system 210. In this case, light from the fundus Er is guided back along the optical path of the irradiation optical system 210 to the perforated mirror 213. The perforated mirror 213 guides the light from the fundus Er to an independent optical path of the light receiving optical system 220 while removing at least a part of noise light caused by reflection on the cornea of ​​the subject's eye E and the optical system inside the device (for example, the lens surface of the objective lens system, etc.).

[0056] The optical path branching member that branches the irradiation optical system 210 and the light receiving optical system 220 is not limited to the perforated mirror 213, and other optical members (for example, a half mirror, etc.) may be used.

[0057] The light receiving optical system 220 of this embodiment has a lens 221, a pinhole plate 223, and a light separating section (light separating unit) 230 on the reflected light path of the mirror with a hole 213.

[0058] The pinhole plate 223 is disposed on a fundus conjugate plane and functions as a confocal aperture in the fundus photographing device 1. That is, when the diopter is properly corrected by the diopter correction unit 240, the light from the fundus Er that has passed through the lens 221 is focused at the opening of the pinhole plate 223. The pinhole plate 223 removes light from positions other than the focal point (or focal plane) of the fundus Er, and the remaining light (light from the focal point) is guided to at least one of the light receiving elements 225, 227, and 229.

[0059] The light separating unit 230 separates light from the fundus Er. In this embodiment, the light separating unit 230 selectively separates the light from the fundus Er. The light separating unit 230 may also serve as a light branching unit that branches the optical path of the light receiving optical system 220. For example, as shown in FIG. 2, the light separating unit 230 may include two dichroic mirrors (dichroic filters) 231 and 232 having different optical separation characteristics (wavelength separation characteristics). The optical path of the light receiving optical system 220 is branched into three by the two dichroic mirrors 231 and 232. At the end of each branched optical path, one of the light receiving elements 225, 227, and 229 is disposed.

[0060] For example, the light separation unit 230 separates the wavelengths of light from the fundus Er and causes the three light receiving elements 225, 227, and 229 to receive light of different wavelength ranges. For example, the light receiving elements 225, 227, and 229 may receive three colors of light, blue, green, and red, one color each. In this case, a color image may be acquired from the light receiving results of the light receiving elements 225, 227, and 229.

[0061] The light separation unit 230 may receive fundus autofluorescence and infrared light, which is fundus reflection of observation light, at different light receiving elements. This may enable infrared images to be captured simultaneously with fluorescent images. In this embodiment, blue light irradiated from the laser light source 211 is used as excitation light for the autofluorescence.

[0062] The control unit 70 forms a fundus image based on, for example, light receiving signals output from the light receiving elements 225, 227, and 229. More specifically, the control unit 70 forms a fundus image in synchronization with the optical scanning by the scanning unit 216. For example, the control unit 70 forms at least one frame (in other words, one sheet) of a fundus image (for each light receiving element) every time the optical scanner 216b for sub-scanning makes a round trip n times (n is an integer equal to or greater than 1). In the following, for convenience, unless otherwise specified, it is assumed that one frame of a fundus image is formed for each round trip of the optical scanner 216b for sub-scanning based on that one round trip. In this embodiment, since three light receiving elements 225, 227, and 229 are provided, the control unit 70 generates up to three types of images based on signals from the respective light receiving elements 225, 227, and 229 every time the optical scanner 216b for sub-scanning makes one round trip.

[0063] <Attachment optical system> The attachment optical system 330 is inserted and removed between the objective optical system 300 of the device body and the subject's eye E. In this embodiment, the attachment optical system 330 is inserted and removed by the examiner attaching and detaching the lens attachment including the attachment optical system 330 to and from the front surface of the device. The attachment optical system 330 may include a plurality of lenses 331 and 332. At least the lens 164 bends the measurement light that has passed through the first pivot point P1 toward the optical axis L, thereby forming a second pivot point P2 at a position conjugate with the optical scanner 134 with respect to the attachment optical system 330 and the objective optical system 158. In other words, the attachment optical system 330 is an optical system that relays the pivot point P1 to the pivot point P2.

[0064] When the attachment optical system 330 is not attached, the SLO optical system 200 can capture a front fundus image at an angle of view of about 60°, and when attached, the SLO optical system 200 can capture a front fundus image at an angle of view of about 100°.

[0065] Whether or not the attachment optical system 330 is attached is detected by a sensor (not shown) provided on the housing, and the result is input to the control unit 70. In this way, the angle of view setting in the SLO optical system 200 is acquired by the control unit 70.

[0066] The control unit 70 may display a plurality of frames of fundus images formed sequentially based on the operation of the above-mentioned device on the monitor 75 in chronological order as observation images. The observation images are moving images consisting of fundus images acquired in approximately real time. The control unit 70 also takes in (captures) some of the plurality of fundus images formed sequentially as photographed images (captured images). At that time, the photographed images are stored in a storage medium. The storage medium in which the photographed images are stored may be a non-volatile storage medium (e.g., a hard disk, a flash memory, etc.). In this embodiment, for example, after a trigger signal (e.g., a release operation signal, etc.) is output, a fundus image formed at a predetermined timing (or period) is captured.

[0067] <Explanation of the operation of the first embodiment> Next, the photographing operation of the device having the above configuration will be described with reference to FIGS.

[0068] <Basic shooting flow> FIG. 4 is a flow chart showing an outline of the flow of the shooting operation.

[0069] First, the control unit 70 selects a photographing operation to be executed (S1). One of a plurality of photographing operations including a photographing operation at a first angle of view and a photographing operation at a second angle of view is selected. The photographing operation may be selected based on an instruction from the examiner each time a new photographing operation is executed. Also, for example, when combination photographing is performed, and the execution order of the plurality of photographing operations is determined in advance, one of the plurality of photographing operations included in the combination photographing may be automatically selected according to the execution order. In this case, the subsequent processing is executed between the photographing operations.

[0070] Next, the control unit 70 determines whether or not the angle of view setting in the selected shooting operation matches the angle of view setting of the SLO optical system 200 at that time (S2).

[0071] If the two angle of view settings match (S2: Yes), various adjustments are made as necessary (S3), and the selected shooting operation is executed (S4). Note that in step S3, at least one of alignment adjustment, diopter correction, adjustment of fixation lamp presentation position, light amount, gain, or exposure time adjustment may be performed.

[0072] In step S2, if the two angle of view settings do not match (S2: No), guidance information is output to the examiner (S5). In this embodiment, the guidance information is displayed via the monitor 80. The guidance information includes information that guides the examiner in mounting / retracting the attachment optical system 330. As a result, the guidance information prompts the examiner to perform an operation to change the angle of view in accordance with the shooting operation, so that even an examiner who is not familiar with the operation can appropriately perform the setting operation of the angle of view in accordance with the shooting operation.

[0073] In this embodiment, after the guidance information is output, when the angle of view setting of the SLO optical system 200 is changed in accordance with the angle of view setting in the shooting operation (S6: Yes), various adjustments other than the angle of view setting are performed (S3). Then, the selected shooting operation is executed (S4). In this case, the appropriate working distance is changed with the attachment optical system 330 being attached or detached. Furthermore, when the attachment optical system 330 is attached or detached, the examiner's face may be temporarily removed from the face support unit 9, so that it may become necessary to adjust the alignment state in the up, down, left, and right directions. For this reason, the control unit 70 may adjust or guide the positional relationship between the subject's eye and the SLO optical system 200 to the alignment target position after the attachment optical system 330 is attached or detached. In addition, if adjustments such as the diopter correction amount and the presentation position of the fixation light are required again after the attachment optical system 330 is attached or detached, the control unit 70 may also adjust or guide them appropriately.

[0074] As described above, in this embodiment, if the angle of view setting for the selected shooting operation does not match the angle of view setting for the SLO optical system 200 at that time (S2: No), guidance information is output to the examiner to guide the examiner in attaching / retracting the attachment optical system 330, so that even an inexperienced examiner can appropriately set the angle of view according to the shooting operation.

[0075] Also, even when combination imaging is performed in which an imaging operation at the first angle of view and an imaging operation at the second angle of view are performed consecutively, the operation for changing the angle of view is prompted by the guidance information at an appropriate timing between the imaging operations, so that imaging can be performed more reliably at an appropriate angle of view. In combination imaging, fluorescent angiographic images of the subject's eye may be captured consecutively at the first angle of view and the second angle of view, respectively, and in this case, the operation for switching the angle of view is smoothly performed based on the guidance information, so that it is possible to suppress missing of imaging of a desired angiographic state.

[0076] According to the flowchart of FIG. 4, if the angle of view setting of the SLO optical system 200 is not changed in accordance with the angle of view setting in the shooting operation (S6: No), shooting cannot proceed. However, this is not necessarily limited to this. For example, after the guidance information is output, when the angle of view setting is not changed and, for example, an instruction to perform shooting is input based on the examiner's operation, confirmation information for confirming whether or not to perform shooting with the non-recommended setting may be output to the examiner. If an instruction to perform shooting is input again after the confirmation information is output, shooting may be performed without changing the angle of view setting of the device. Alternatively, if the angle of view change in response to the guidance information is not complied with, if there is another unexecuted shooting operation that does not require a change in the angle of view, that operation may be performed, and then the guidance information may be output again.

[0077] <GUI for accepting input operations for shooting range> In addition, in this embodiment, prior to the step (S1) of selecting the shooting operation in FIG. 4, an input operation for the shooting range may be received from the examiner. Based on the input operation received at this time, the shooting operation may be selected in step S1.

[0078] In this case, as shown in FIG. 5, in this embodiment, a GUI 500 for receiving an input operation of the shooting range is displayed on the monitor. In this embodiment, the GUI 500 includes an input area 501 for the shooting range with respect to the fundus oculi which is the shooting site. On the area 501, a fundus image 503 of the eye to be examined taken at the second angle of view in advance is arranged. For example, in this embodiment, on the area 501, the examiner can specify the shooting position of the fundus image at the first angle of view. For example, on the area 501, the center position of the fundus image at the first angle of view may be specified as the shooting position with the pointer 505.

[0079] Thereby, after the attachment optical system 330 is retracted based on the guiding information, the presentation position of the fixation lamp presented to the eye to be examined is adjusted or guided according to the shooting position specified by the pointer 505. Therefore, after switching the angle of view of the SLO optical system 200 from the second angle of view to the first angle of view, it is easy to perform shooting smoothly at the desired shooting position.

[0080] Note that in this embodiment, by designating an arbitrary position on the area 501, the center position of the fundus image at the first angle of view can be arbitrarily set. However, it is not necessarily limited to this, and the shooting positions that can be designated on the area 501 may be predetermined.

[0081] <Second Embodiment> Next, a second embodiment will be described. The fundus imaging apparatus 1 according to the second embodiment further includes an OCT optical system 100 shown in FIG. 6 in addition to the configuration of the first embodiment. The OCT optical system 100 acquires OCT data of the fundus oculi.

[0082] <OCT Optical System> The OCT optical system 100 guides measurement light to the eye E by the light guide optical system 130. The OCT optical system 100 guides reference light to the reference optical system 140. The OCT optical system 100 causes a detector (light receiving element) 120 to receive interference signal light obtained by interference between the measurement light reflected by the eye E and the reference light.

[0083] The SD-OCT method is used for the OCT optical system 100. The OCT light source 102 emits a light beam with a short coherence length, and the detector 120 is a spectroscopic detector that separates and detects the spectral interference signal for each wavelength component.

[0084] The coupler (splitter) 104 is used as a first optical splitter and splits the light emitted from the OCT light source 102 into a measurement optical path and a reference optical path. The coupler 110, for example, guides the light from the OCT light source 102 to an optical fiber 112 on the measurement optical path side and also guides the light to a reference optical system 140 on the reference optical path side.

[0085] <Light guide optical system> The light guiding optical system 130 is provided to guide the measurement light to the eye E. For example, the light guiding optical system 130 may be provided with an optical fiber 112, a collimator lens 131, a variable beam expander 132, an optical scanner 134, and an objective lens 320 in this order. In this case, the measurement light is emitted from the exit end of the optical fiber 112 and is made into a parallel beam by the collimator lens 131. After that, the measurement light is directed to the optical scanner 134 via the focusing lens 133 in a state where the desired light beam diameter is obtained by the variable beam expander 132. The light that has passed through the optical scanner 134 is irradiated to the eye E via the objective lens 320. A first pivot point P1 is formed at a position conjugate with the optical scanner 134 with respect to the objective lens 320. By positioning the anterior eye segment at this pivot point P1, the measurement light reaches the fundus without being vignetted. In addition, the measurement light is scanned on the fundus in accordance with the operation of the optical scanner 134. At this time, the measurement light is scattered and reflected by the tissue of the fundus.

[0086] The optical scanner 134 may scan the measurement light in the XY directions (transverse directions) on the eye E. The optical scanner 134 is, for example, two galvanometer mirrors, and the reflection angle is arbitrarily adjusted by a driving mechanism. The light beam emitted from the OCT light source 102 has its reflection (traveling) direction changed, and is scanned in an arbitrary direction on the fundus. As the optical scanner 134, for example, in addition to a reflection mirror (galvanometer mirror, polygon mirror, resonant scanner), an acousto-optic element (AOM) that changes the traveling (deflection) direction of light may be used.

[0087] The scattered light (reflected light) from the eye E due to the measurement light travels back along the path taken when the light was projected, is incident on the optical fiber 112, and reaches the coupler 110. The coupler 110 guides the light from the optical fiber 112 to an optical path leading to the detector 120.

[0088] <Attachment optical system> In the OCT device of the embodiment, the attachment optical system 330 is inserted and removed between the objective lens 320 in the light guiding optical system 130 and the subject's eye E. The lens attachment including the attachment optical system 330 is attached and detached (inserted and removed) to and from a housing surface not shown, whereby the attachment optical system 330 is inserted and removed between the objective lens 320 on the device body side and the subject's eye E. When the attachment optical system 330 is in a retracted state, it can scan in a range of about 60°, and when it is inserted, it can scan in a range of about 100°.

[0089] <Reference optical system> The reference optical system 140 generates a reference light to be combined with the fundus reflected light of the measurement light. The reference light passing through the reference optical system 140 is combined with the light from the measurement optical path by a coupler 149 and interferes with each other. The reference optical system 140 may be a Michelson type or a Mach-Zehnder type.

[0090] 6 is formed by a transmission optical system. In this case, the reference optical system 140 guides the light from the coupler 110 to the detector 120 by transmitting the light without returning it. However, the reference optical system 140 may be formed by, for example, a reflection optical system, and guide the light from the coupler 110 to the detector 120 by reflecting it with the reflection optical system.

[0091] In this embodiment, the reference optical system 140 may be provided with a plurality of reference optical paths. For example, in Fig. 6, the reference optical path is branched by a coupler 141 into an optical path (first branched optical path in this embodiment) passing through a fiber 142 and an optical path (second branched optical path in this embodiment) passing through a fiber 143. The fibers 142 and 143 are connected to a coupler 145, whereby the two branched optical paths are combined and input to a coupler 149 via a reference optical path adjustment unit 147 and a polarization adjustment unit 148.

[0092] In this embodiment, the reference light from the coupler 110 is simultaneously guided by the coupler 141 to the fiber 142 and the fiber 143. The light that has passed through both the fiber 142 and the fiber 143 is multiplexed with the measurement light (fundus reflection light) in the coupler 149.

[0093] The optical path length difference between the fiber 142 and the fiber 143, that is, the optical path length difference between the first branched optical path and the second branched optical path, may be a fixed value. In this embodiment, the optical path length difference is set to be substantially the same as the optical path length of the attachment optical system 330. This eliminates the need to significantly adjust the optical path length difference before and after inserting and removing the attachment optical system 330.

[0094] However, at least one of the measurement light path and the reference light path may be provided with a reference light path adjustment unit 147 for adjusting the light path length difference between the measurement light and the reference light. The adjustment range of the light path length in the reference light path adjustment unit 147 is preferably set sufficiently short with respect to the light path length difference between the fiber 142 and the fiber 143 (in other words, the light path length difference between the first branch light path and the second branch light path).

[0095] <Photodetector> The detector 120 is provided to detect interference between the light from the measurement optical path and the light from the reference optical path. In this embodiment, the detector 120 is a spectroscopic detector, and includes, for example, a spectroscope and a line sensor, and the measurement light and the reference light combined by the coupler 149 are dispersed by the spectroscope and received by different areas (pixels) of the line sensor for each wavelength. As a result, the output for each pixel is obtained as a spectral interference signal.

[0096] <Getting depth information> The control unit 70 processes (Fourier analysis) the spectral signal detected by the detector 120 to obtain OCT data of the subject's eye.

[0097] The spectrum signal (spectral data) may be rewritten as a function of wavelength λ and converted into a function I(k) that is equally spaced with respect to wavenumber k (=2π / λ). Alternatively, it may be acquired from the beginning as a function I(k) that is equally spaced with respect to wavenumber k (K-CLOCK technology). The arithmetic controller may obtain OCT data in the depth (Z) domain by Fourier transforming the spectrum signal in the wavenumber k space.

[0098] Furthermore, the information after the Fourier transform may be represented as a signal including real and imaginary components in the Z space. The control unit 70 may obtain the OCT data by calculating the absolute values ​​of the real and imaginary components of the signal in the Z space.

[0099] Here, both the reference light via the first branched optical path and the reference light via the second branched optical path are guided to the coupler 149, and each is multiplexed with the measurement light. In order to selectively cause the reference light via the first branched optical path and the reference light via the second branched optical path to interfere with the measurement light, an optical path switching unit (e.g., an optical switch) not shown may be disposed on the reference optical system.

[0100] <Explanation of the operation of the second embodiment> In the fundus imaging device 1 of the second embodiment, the imaging range can be changed by controlling the scanning range of the optical scanner 134 during OCT imaging. At this time, the angle of view defined by the objective optical system of the device is the maximum value of the changeable imaging range. In other words, when the attachment optical system 330 is in the retracted state, the imaging range of the OCT data can be changed within a range below the maximum value of 60°, and when the attachment optical system 330 is in the inserted state, the imaging range of the OCT data can be changed within a range below the maximum value of 100°.

[0101] 7, the photographing range is designated via a GUI 500, similarly to the first embodiment. The photographing range is designated on an area 501 provided in the GUI 500 in which a frontal fundus image 502 is displayed.

[0102] In this embodiment, the front fundus image shown in the area 501 is acquired via the front photographing optical system 200 .

[0103] First, a case will be described where a fundus image 502 previously captured at a second angle of view (approximately 100°) is displayed in the area 501. However, this is not necessarily limited to this, and the fundus front image may be an observation image acquired at any time by the front photographing optical system 200.

[0104] In the second embodiment, one of a plurality of predetermined scan patterns is selected, and the position and range to be scanned with the selected scan pattern are specified on the area 501. Known scan patterns include map, multi, cross, radial, and line, for example.

[0105] 7 shows an example in which a single linear pattern (line pattern) is selected as the scan pattern. The position and range of capturing OCT data are set by the examiner setting a scan line 506 at an arbitrary position and length on the region 501. For example, the scan line 506 may be set by specifying the start point and end point of the scan line 506 on the region 501.

[0106] However, this is not necessarily limited to this, and the length of the scan line 506 may be set by inputting a numerical value.

[0107] In this embodiment, the control unit 70 determines whether or not to output guidance information to guide the mounting / retraction of the attachment optical system 330 depending on the angle of view setting of the device and the size and position of the shooting range selected in the area 501.

[0108] For example, when the attachment optical system 330 is not attached to the OCT optical system 100 and the first angle of view is set, if the scan line 506 is set in a range narrower than the first angle of view, imaging is performed without outputting guidance information. At this time, the position of the fixation light may be controlled according to the imaging position.

[0109] In addition, when the OCT optical system 100 is set to the first angle of view, if the scan line 506 is set in a range wider than the first angle of view, guidance information for guiding the attachment optical system 330 to be attached is output, and after the attachment optical system 330 is attached, photographing is performed.

[0110] Also, for example, when the attachment optical system 330 is attached in advance to the OCT optical system 100 and set to the second angle of view, if the scan line 506 is set in the range from the second angle of view to the first angle of view, the scanning range is adjusted according to the scan line 506 and imaging is performed without outputting guidance information.

[0111] Furthermore, when the OCT optical system 100 is set to the second angle of view, if the scan line 506 is set in a range narrower than the first angle of view, guidance information for guiding the retraction of the attachment optical system 330 is output. After that, the attachment optical system 330 is retracted, and then photographing is performed. At this time, even when the second angle of view is set, it is possible to limit the scanning range of the optical scanner 134 to a range narrower than the first angle of view and photograph, but in that case, photographing cannot be performed with good image quality compared to when the OCT optical system 100 is set to the first angle of view. Therefore, in this embodiment, by guiding to photograph with the OCT optical system 100 set to the first angle of view, a fundus image is photographed with more appropriate image quality.

[0112] At this time, the threshold value of the length of the scan line 506, which is the threshold value for determining whether or not the guidance information is output, is a value corresponding to the first angle of view, but is not necessarily limited to this and can be appropriately set within a range smaller than the first angle of view.

[0113] Here, it is assumed that a front image of the fundus photographed at the second angle of view (approximately 100°) is displayed in the area 501, but the same operation may be performed when a front image of the fundus photographed at the first angle of view (approximately 60°) is displayed in the area 501. In this case, the scan line 506 may be set for the entire area within the area 501, including not only the inside but also the outside of the area of ​​the fundus image.

[0114] In the second embodiment, whether or not to output guidance information for guiding the mounting / retraction of the attachment optical system 330 was determined based on the angle of view setting of the device and the size and position of the shooting range selected in area 501, but this is not necessarily limited to this.

[0115] For example, the size of the imaging range that can be input may be limited in advance for each angle of view setting of the device so that input of the imaging range setting operation is not accepted even in the imaging range where the attachment optical system 330 should be attached / retracted.

[0116] Alternatively, instead of outputting the guidance information, a warning may be output to the examiner that the setting of the imaging range is inappropriate. Even after the output of the warning, if an operation input of an imaging instruction is received without changing the angle of view setting, imaging may be performed within the range of the angle of view that can be captured.

[0117] <Modification> While the present disclosure has been described above based on the embodiments and examples, the present disclosure is not necessarily limited to the above-described embodiments and examples, and various modifications are possible.

[0118] For example, when fluorescent contrast imaging is performed, imaging operations may be set for each time phase (time period) in the contrast imaging. Each time phase may be separated by, for example, the time measured by a contrast timer. As one concrete example, 1st time zone: 00'00"~01'00" Second time zone: 01'00"~05'00" Third time zone: 05'00"~10'00" · · · As described above, the time phases may be divided, and one or more imaging operations to be performed in each time phase may be set for each time phase.

[0119] In this case, the imaging operation may be set so that imaging is performed once each at the first angle of view and the second angle of view in each time phase. In this case, not only a fluorescent contrast image but also a color image, an OCT image, etc. may be set to be captured. In addition, in order to reliably capture a large change in the early stage of contrast enhancement, imaging may be performed with either the first angle of view or the second angle of view fixed, and multiple imaging operations with the first angle of view and the second angle of view may be set from the middle stage of contrast enhancement onwards, when the change is relatively small.

[0120] Even in this case, mounting / retraction operation guidance information for the attachment optical system 330 may be output to the examiner every time it becomes necessary to change the angle of view in the forward or backward photographing operation. [Explanation of symbols]

[0121] 1 Fundus photography device 70 Control section 100 OCT optics 200 SLO optics 300 Objective Optical System 330 Attachment Optical System

Claims

1. an imaging optical system that captures an ophthalmic image of the subject's eye via an objective optical system; a field angle changing means for changing an angle of view of the photographing optical system at least between a first field angle and a second field angle larger than the first field angle by switching the objective optical system based on an operation by an examiner; a selection means for selecting one of a plurality of photographing operations including at least a combination photographing operation in which a photographing operation of a fluorescent contrast image using the first angle of view and a photographing operation of a fluorescent contrast image using the second angle of view are successively performed; a guidance means for outputting, when the combination photographing is selected, guidance information for guiding an examiner to perform the operation to change the angle of view of the photographing optical system, at a timing between an operation of photographing the fluorescence contrast image with the first angle of view and an operation of photographing the fluorescence contrast image with the second angle of view; An ophthalmic imaging apparatus comprising:

2. 2. An ophthalmic photographing device as described in claim 1, further outputting second guidance information to the examiner for guiding the examiner in adjusting the positional relationship between the test eye and the photographing optical system at least at a timing between the photographing operation at the first angle of view and the photographing operation at the second angle of view.

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