Ophthalmic device

Abstract

To provide an ophthalmologic apparatus which can match measurement results in the state (characteristic) of an eye surface even when images of the eye surface are captured in different imaging methods.SOLUTION: An ophthalmologic apparatus comprises: an excitation light source which excites fluorescent light from a fluorescent dyeing agent applied to an anterior eye part in a subject eye; a projection unit which projects a plurality of rings to the anterior eye part; an imaging optical system which images the anterior eye part; and an imaging control unit which controls the imaging optical system so as to capture a plurality of first photographed images being the images of the anterior eye part illuminated by the excitation light source and capture a plurality of second photographed images being the images of the anterior eye part projected by the projection unit.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an ophthalmic apparatus.

Background Art

[0002] Conventionally, an ophthalmic apparatus that irradiates light output from a light source onto the anterior eye part of an eye to be examined and captures an image of the eye surface is known. For example, in the ophthalmic apparatus described in Patent Document 1, when capturing an image of the eye surface, there are configurations of irradiating ring light onto the anterior eye part of the eye to be examined for imaging, and of instilling a fluorescent dye into the anterior eye part of the eye to be examined for fluorescence angiography imaging.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the ophthalmic apparatus described in Patent Document 1, means for irradiating ring light to capture an image of the eye surface and means for capturing an image of the eye surface by fluorescence angiography are described, but there is no description regarding associating the imaging results of these two imaging means. Although the symptoms of dry eye can be grasped in either the imaging by irradiating ring light or the imaging by fluorescence angiography, in the ophthalmic apparatus described in Patent Document 1, when capturing an image of the eye surface by different imaging means, the measurement results regarding the state (characteristics) of the eye surface may be different. When capturing an image of the eye surface of the same eye to be examined, it is preferable that the measurement results be the same regardless of the imaging means even if the imaging means are different.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide an ophthalmic apparatus capable of verifying whether measurement results regarding the state (characteristics) of the ocular surface match when images of the ocular surface are captured by different imaging methods.

Means for Solving the Problems

[0006] To achieve the above object, an ophthalmic apparatus includes an excitation light source that excites fluorescence from a fluorescent dye instilled in the anterior eye part of an eye to be examined, a projection unit that projects a plurality of rings onto the anterior eye part, an imaging optical system that images the anterior eye part, and an imaging control unit that controls the imaging optical system to capture a plurality of first captured images that are images of the anterior eye part illuminated by the excitation light source and a plurality of second captured images that are images of the anterior eye part projected by the projection unit.

[0007] That is, when imaging the anterior eye part of an eye to be examined, the ophthalmic apparatus controls imaging that excites fluorescence from a fluorescent dye and imaging that projects a plurality of rings onto the anterior eye part of the eye to be examined. Thereby, for example, when imaging an image of the ocular surface, it is possible to obtain images of the same characteristics (or the same event) from an image captured by exciting fluorescence from a fluorescent staining material and an image captured by ring projection. Therefore, by comparing images captured by different imaging methods, it is possible to verify whether measurement results regarding the state of the ocular surface match.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0009] Here, embodiments of the present invention will be described in the following order. (1) Configuration of the ophthalmic device: (2) Imaging control processing and display processing: (3) Other embodiments:

[0010] (1) Configuration of the ophthalmic device: An ophthalmic device 1 according to an embodiment of the present invention includes a housing, and an optical system and a control unit used for a plurality of types of measurements are provided in the housing. In the present embodiment, the ophthalmic device 1 has at least a function of measuring the state of the eye surface and a function of displaying an image of the eye surface of the eye to be examined on a display unit.

[0011] FIG. 1 is a diagram showing an optical system. FIG. 2 is a block diagram for explaining the overall configuration of an ophthalmic device 1 according to an embodiment of the present invention including a control unit. Hereinafter, the ophthalmic device 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. As shown in FIG. 2, the ophthalmic device 1 includes a head unit 602 in which an optical system for measuring the eye to be examined is arranged, and a main body unit 601 including a control unit 600 that controls switching of the optical system in the head unit 602.

[0012] The main body unit 601 includes an XYZ drive control unit 630 that moves the head unit 602 in the XYZ (left - right, up - down, front - back) directions with respect to the main body unit 601, a joystick 640 that instructs adjustment of the spatial position of the head unit 602, a display unit 650 that displays an image of the eye to be examined taken and a measurement result of the eye refractive power, etc., a touch panel 660 that receives instructions for measurement items, etc., a memory 670 used in the control processing of the control unit 600, and a fixation mark control unit 680 that controls the fixation mark unit.

[0013] (Configuration of the optical system) FIG. 1 shows the optical system of the ophthalmic apparatus 1. The optical system includes an alignment optical system 100 including optical elements and the like on the optical path from the light source 101 to the profile sensors 107 and 108. Further, the optical system includes a photographing optical system 300 including optical elements and the like on the optical path from the light sources 301, 302, 300a to the two-dimensional imaging element (CCD) 306. Furthermore, the optical system includes a fixation optical system 400 including optical elements and the like on the optical path from the light source 514 through the relay lens 403 to the eye E to be examined, and an eye refractive power optical system 500 for detecting the refractive power of the eye to be examined. As shown in FIG. 1, a part of each optical system is shared. In the present embodiment, plane glasses 510 and 511 for measuring the anterior segment of the eye are arranged at the aperture portion disposed in front of the eye E to be examined.

[0014] (Alignment optical system 100) In the alignment optical system 100, the light from the light source 101 is reflected by the hot mirror 102, passes through the objective lens 103, is reflected by the hot mirror 104, and then passes through the plane glasses 511 and 510 and irradiates the cornea of the eye E to be examined. In this embodiment, the light source 101 is an LED that outputs infrared light.

[0015] The light reflected by the cornea is received by the lenses 105 and profile sensor 107, and the lenses 106 and profile sensor 108 that are symmetrically arranged with respect to the principal optical axis O1. In the present embodiment, the optical axis is a line segment connecting the centers of the lenses constituting the optical system, and each lens is arranged so that its thickness is rotationally invariant with respect to the optical axis (the same applies hereinafter).

[0016] In this embodiment, when the position of the eye to be examined in the three-dimensional direction is an appropriate position, the positions where the light reflected by the cornea is detected by the profile sensor 107 and the profile sensor 108 are predetermined. The control unit 600 of the main body unit 601 instructs the XYZ drive control unit 630 to move the head unit 602 in the three-dimensional direction so that the positions where the light reflected by the cornea is detected by the profile sensor 107 and the profile sensor 108 become the predetermined positions. As a result, the head unit 602 and the optical system inside thereof are aligned with the eye to be examined in the three-dimensional direction.

[0017] Note that various methods may be adopted for the alignment method. For example, a configuration in which the control unit 600 performs auto-alignment (fine adjustment) after the examiner performs rough alignment can be adopted. For rough alignment, for example, the examiner visually recognizes the bright spot due to the reflection from the cornea on the image of the eye to be examined displayed on the display unit 650, and further moves the head unit 602 so that the bright spot enters a predetermined range with the joystick 640. Such a method can be adopted. Of course, the alignment optical system is not limited to the example shown in FIG. 1. For example, a configuration in which the optical system for performing alignment in the Z direction and the optical system for performing alignment in the XY direction are different optical systems (including partial overlap) may be adopted.

[0018] (Fixation optical system 400) When the fixation optical system 400 is used, the light from the light source 514 is made parallel light by the collimator lens 513 and irradiated onto the fixation target 512. Then, the light from the fixation target 512 passes through the relay lens 403, is reflected by the reflection mirror 404, passes through the hot mirror 506, and is reflected by the dichroic mirror 304 and passes through the main optical axis O1. After that, the light passes through the objective lens 303, the hot mirror 104, and the plane glasses 511 and 510 and forms an image on the retina of the eye to be examined E. Therefore, it is desirable that the fixation target 512 and the retinal position of the eye to be examined are substantially conjugate. The eye to be examined is fixated based on the fixation target 512, and measurement of eye characteristics such as eye refractive power measurement becomes possible. The light source 514 employs an LED that outputs visible light that can be visually recognized by the subject (or the eye to be examined).

[0019] When measuring the eye refractive power, the control unit 600 outputs a control instruction to the fixation target control unit 680. As a result, the fixation target control unit 680 controls the movement of the fixation target unit (fixation target 512, collimator lens 513, and light source 514) so that the fixation target and the retinal position of the eye to be examined are substantially conjugate, and fixes the eye to be examined. Then, the control unit 600 outputs a control instruction to the fixation target control unit 680, and the fixation target control unit 680 moves the fixation target unit by a predetermined distance to make it in a cloudy state, and measures the eye refractive power. Therefore, the fixation target unit can move back and forth along the optical axis according to the signal from the control unit 600.

[0020] (Eye refractive power optical system 500) When the eye refractive power is measured, the eye refractive power optical system 500 is used. In the present embodiment, the eye refractive power optical system 500 includes a light projecting optical system and a light receiving optical system. The eye refractive power optical system 500 includes optical elements and the like on the optical path from the light source 501 to the eye to be examined E through the mirror 503 and the plane glass 511. Specifically, when the eye refractive power is measured, the measurement light (reflected light) from the light source 501 is condensed by the condenser lens 502, reflected by the mirror 503, and passes through the hole at the center of the perforated mirror 504. Then, the measurement light passes through the parallel plane glass 505 as an optical deflection member disposed obliquely with respect to the optical axis O2, and is further reflected by the hot mirror 506 and the dichroic mirror 304 and passes through the principal optical axis O1.

[0021] Note that the parallel plane glass 505 as the optical deflection member is installed so that the glass surface is inclined by a predetermined inclination angle with respect to the axis perpendicular to the optical axis O2 from the state parallel to the optical axis O2. Here, the inclination angle is an angle smaller than 90 degrees (for example, 45 degrees, etc.), and may be determined according to the displacement between the measurement light and the optical axis. In the present embodiment, the parallel plane glass 505 is rotatable about the optical axis O2.

[0022] The measurement light reflected by the dichroic mirror 304 passes through the objective lens 303, the hot mirror 104, the flat glass 511, and the flat glass 510 and irradiates the eye to be examined E. When the measurement light reaches the eye to be examined E, the measurement light changes according to the refractive power of the eye to be examined E and is reflected by the fundus of the eye to be examined E. The reflected light from the fundus of the eye to be examined E passes through the flat glass 510, the flat glass 511, the hot mirror 104, and the objective lens 303 in the reverse path of the irradiation. Further, the reflected light is reflected by the dichroic mirror 304 and the hot mirror 506, passes through the optical axis O2, passes through the parallel flat glass 505, is then reflected by the perforated mirror 504, and passes through the lens 507. Thereafter, the reflected light is imaged in a ring shape (ring image) on the two-dimensional image sensor (CCD) 509 by the ring lens 508.

[0023] Note that the light source 501 uses infrared light with a longer wavelength than the alignment light (light source 101) and the measurement light (light sources 301 and 302). In this embodiment, an SLD (superluminescent diode) is used, but it is not limited thereto, and an LED or a laser diode (LD) used for the light source 101 or the like may be used.

[0024] In this embodiment, the parallel flat glass 505 is disposed at a position conjugate to the pupil of the eye to be examined E. Since the parallel flat glass 505 has a refractive index larger than that of air, the traveling direction of the light incident on the parallel flat glass 505 changes, and the traveling direction of the light output from the parallel flat glass 505 also changes. As a result, the output light from the parallel flat glass 505 is at a position shifted by a predetermined distance from the incident light and is parallel to the traveling direction of the incident light.

[0025] (Imaging optical system 300 when imaging using light sources 301 and 302) The imaging optical system 300 may perform imaging using the light sources 301 and 302, or may perform imaging using the light source 300a described later. First, the imaging optical system 300 that performs imaging using the light sources 301 and 302 will be described. In the present embodiment, the light sources 301 and 302 are blue LEDs that output blue visible light, and the wavelength range of the light output from the light sources 301 and 302 is, for example, the wavelength range of 450 nm to 520 nm. This is to excite the instilled fluorescent dye by instilling fluorescein, which is a fluorescent dye, into the eye E to be examined and irradiating the eye E to be examined with the light sources 301 and 302. That is, in the present embodiment, it is possible to observe the ocular surface by irradiating the anterior ocular region of the fluorescein-stained eye E to be examined with the light sources 301 and 302. When the anterior ocular region stained with fluorescein is irradiated with the light sources 301 and 302, the fluorescein is excited and emits light in green (fluorescent green).

[0026] When the imaging optical system 300 using the light sources 301 and 302 is used to measure the state (characteristics) of the ocular surface, the anterior ocular region including the corneal part of the eye E to be examined is irradiated with light by the light source 301 and the light source 302 arranged on the eye E side of the head part 602. In this state, an image of the anterior ocular part of the eye E to be examined is acquired by the objective lens 303, the green filter 307, the imaging lens 305, and the two-dimensional imaging element 306, and the acquired image of the anterior ocular part of the eye E to be examined is displayed on the display unit 650. The green filter 307 is a filter that selectively transmits the green color emitted by fluorescein (in other words, cuts other wavelengths), and by the light excited by fluorescence passing through this green filter 307, a clearer captured image can be obtained.

[0027] In addition, in the present embodiment, the light sources 301 and 302 output light with a shorter wavelength than the light source 101. Therefore, the hot mirror 104 transmits the light for measurement (measurement light) and reflects the light for alignment (alignment light, light from the light source 101). Also, the dichroic mirror 304 is set with a reflection / transmission wavelength region so as to transmit the measurement light. As a result, the alignment light and the measurement light are appropriately split, enabling each measurement. Note that the light sources 301 and 302 correspond to the "excitation light sources" in the present embodiment.

[0028] (Imaging optical system 300 when performing imaging using the light source 300a) Next, the imaging optical system 300 when performing imaging using the light source 300a will be described. As described above, in the ophthalmic device 1 according to the present embodiment, it is possible to perform observation of the eye surface using the light source 300a. The light source 300a is attached to the tip of the viewing port (on the side of the eye to be examined E). In the present embodiment, the light source 300a is configured to project a ring-shaped pattern centered on the optical axis. In the present embodiment, the ring-shaped pattern has a plurality of rings, and the diameters of the respective rings are different. Also, when the distance between the eye to be examined E and the light source 300a is constant, the larger the diameter of the ring, the wider the range of the region measurable by the ring. Of course, the configuration of the light source 300a may be various configurations, and may be a configuration having one light source that outputs light from a plurality of rings of the ring-shaped pattern, or may be a configuration having a plurality of light sources corresponding to each of the plurality of rings.

[0029] When the light source 300a is turned on, light is irradiated onto the eye E to be examined and the eye surface from multiple directions. In this embodiment, the light source 300a is a green light-emitting diode (LED). Also, the light source 300a is not limited to a green LED and may be, for example, a white LED. That is, as described above, the imaging optical system 300 is provided with a green filter 307. Therefore, when the light source 300a is a green LED, a green captured image can be obtained directly. On the other hand, when the light source 300a is a white LED, a green captured image can be obtained by passing through the green filter 307. Note that green light is output from the anterior eye part stained with fluorescein, and observation and imaging are performed using the green light. In this embodiment, the light for observing and imaging the anterior eye part illuminated in a ring shape by the light source 300a is also green. For this reason, in this embodiment, both the anterior eye part stained with fluorescein and the anterior eye part illuminated in a ring shape are observed and imaged with green light. Therefore, the examiner can easily compare the two. If observation and measurement with the same color are not required, the light source 300a does not have to be green, or the green filter 307 may be omitted.

[0030] In this embodiment, when the light output from the light source 300a irradiates the eye surface, an image of the anterior eye part of the eye E to be examined is obtained by the objective lens 303, the green filter 307, the imaging lens 305, and the two-dimensional imaging device 306. Note that it is sufficient if the light source 300a can illuminate the part to be measured so that the part to be measured is imaged by the two-dimensional imaging device 306. Also, a configuration in which a ring pattern is projected by the light source 300a corresponds to the "projection unit" in this embodiment.

[0031] Thus, in this embodiment, the imaging of the ocular surface includes imaging that excites fluorescein instilled into the eye E to be examined by irradiation from the above-described light sources 301 and 302, and imaging by projecting a ring onto the eye E to be examined by irradiation from the light source 300a. By controlling the lighting and extinguishing of each of these light sources 301 and 302 and the light source 300a, imaging of the ocular surface can be performed using both imaging that excites fluorescence and imaging that projects a ring. That is, in this embodiment, imaging of the ocular surface is possible in a plurality of imaging modes.

[0032] FIG. 3 is a diagram schematically showing an imaging optical system 300 including the light sources 301, 302, and 300a. By controlling the light sources 301 and 302, or the light source 300a, and the two-dimensional image sensor 306, an image of the anterior segment of the eye E to be examined is acquired. That is, by causing the control unit 600 to turn on the light sources 301 and 302 and turn off the light source 300a, the light output from the light sources 301 and 302 irradiates the ocular surface, and the light reflected from the ocular surface passes through the objective lens 303, the green filter 307, and the imaging lens 305 and forms an image on the two-dimensional image sensor 306, whereby an image of the anterior segment of the eye E to be examined is acquired. On the other hand, by causing the control unit 600 to turn on the light source 300a and turn off the light sources 301 and 302, the light output from the light source 300a irradiates the ocular surface in a ring shape, and the light reflected from the ocular surface passes through the objective lens 303, the green filter 307, and the imaging lens 305 and forms an image on the two-dimensional image sensor 306, whereby an image of the anterior segment of the eye E to be examined is acquired.

[0033] Note that the image of the anterior eye segment illuminated by the light sources 301 and 302 that excite fluorescence corresponds to the "first captured image" in the present embodiment, and the image of the anterior eye segment illuminated by the projection unit (i.e., ring imaging) using the light source 300a corresponds to the "second captured image" in the present embodiment. Also, as described above, in the present embodiment, the eye surface can be captured in a plurality of imaging modes. Among the plurality of imaging modes, imaging that excites fluorescence by fluorescein staining corresponds to the "first imaging mode" in the present embodiment. In other words, the first captured image described above is captured in the first imaging mode. Also, among the plurality of imaging modes, imaging that projects a ring onto the anterior eye segment corresponds to the "second imaging mode" in the present embodiment. In other words, the second captured image described above is captured in the second imaging mode. And, among the plurality of imaging modes, imaging that uses both imaging that excites fluorescence by fluorescein staining and imaging that projects a ring onto the anterior eye segment corresponds to the "third imaging mode" in the present embodiment. In other words, the first captured image and the second captured image described above are captured in the third imaging mode.

[0034] Also, in the present embodiment, the imaging target of the image captured by the imaging optical system 300 is a specific part of the eye E to be examined. Specifically, the eye surface is the imaging target.

[0035] (2) Imaging control process and display process: Next, the imaging control for capturing an image of the eye surface and the control for displaying the captured image on the display unit 650 (display process) will be described. The imaging control and the display process of the image are realized by the control unit 600 executing a control program (not shown). The control unit 600 that executes the control program functions as an imaging control unit 600a and a display processing unit 600b.

[0036] The imaging control unit 600a is a program module that controls the imaging of a first captured image illuminated by an excitation light source that excites fluorescence from a fluorescent staining material (fluorescein), and the imaging of a second captured image that projects ring light onto the anterior eye segment. In the present embodiment, the imaging control unit 600a accepts a selection of any one of a first imaging mode for imaging the first captured image described above, a second imaging mode for imaging the second captured image, and a third imaging mode for imaging both the first captured image and the second captured image, and performs imaging corresponding to the selected mode. Further, when performing imaging in each mode, the control unit 600 controls the on / off switching of the light source 300a of the ring light and the light sources 301 and 302 that excite fluorescence, and also controls the two-dimensional imaging element 306. The display processing unit 600b is a program module that performs processing for displaying the image captured by the imaging control unit 600a on a display unit 650 such as a display.

[0037] FIG. 4 is a flowchart showing an example of image capturing control and image display processing. Here, as a premise for executing the control in the flowchart of FIG. 4, general imaging of the ocular surface will be described. Conventionally, for imaging of the ocular surface that is known, imaging using fluorescein staining has been performed. However, in imaging using fluorescein staining, since a staining solution is instilled into the test eye E, there is a risk of side reactions depending on the condition and constitution of the subject (or examinee), and there may be cases where it is desired to avoid using the staining solution. In such cases, conventionally, imaging of the ocular surface by ring projection that does not require a staining solution is performed. On the other hand, between imaging by ring projection and imaging by fluorescein staining, there are more findings and achievements in imaging by fluorescein staining, and the reliability of the measurement results regarding the condition (characteristics) of the ocular surface is high. However, when comparing imaging by fluorescein staining and imaging by ring projection, even when measuring the same characteristic (or the same event), the results may not be the same. For example, there is a possibility that the BUT (tear film Break-Up Time) obtained by imaging using fluorescein staining does not match the BUT obtained by ring projection. If the measurement results obtained by fluorescein staining and the measurement results obtained by ring projection do not match, the reliability of the measurement results may decrease with only one of the measurement results. Therefore, in the present embodiment, a configuration is provided that enables verification of whether the measurement results obtained by fluorescein staining and the measurement results obtained by ring projection match.

[0038] Hereinafter, the flowchart of FIG. 4 will be specifically described. Note that the control shown in this flowchart is executed, for example, when the subject (or examinee) sets his / her head and jaw at the predetermined positions of the ophthalmic device 1 and the examiner instructs the start of measurement of the ocular surface.

[0039] The control unit 600 first checks the shooting mode (step S1). Specifically, it checks which shooting mode (shooting pattern) the shooting mode is. As described above, in this embodiment, the shooting modes include a first shooting mode in which fluorescein is instilled into the eye to excite fluorescence, a second shooting mode in which ring light is projected onto the anterior eye, and a third shooting mode using a ring shooting mode and a fluorescence excitation mode. Since the first shooting mode involves instilling fluorescein into the subject eye E, there is a possibility of some side reactions. Therefore, for subjects with relatively mild dry eye symptoms, it is preferable to capture an image of the ocular surface using the second shooting mode.

[0040] Therefore, in step S2, it is determined whether or not the shooting mode confirmed in step S1 is the second shooting mode. Note that since steps S1 and S2 have substantially the same content, steps S1 and S2 may be executed simultaneously, or step S1 may be omitted and the control in this flowchart may be started from step S2.

[0041] If it is affirmatively determined in this step S2, that is, if it is determined that the shooting mode is the second shooting mode, alignment in the XYZ directions is performed (step S3). That is, the control unit 600 drives the head unit 602 in the three-dimensional directions of XYZ to perform alignment (positioning) with respect to the subject eye E. Specifically, the control unit 600 gives an instruction to the XYZ drive control unit 630 to move the head unit 602. At this time, the control unit 600 gives an instruction to the XYZ drive control unit 630 so that the head unit 602 moves a predetermined amount toward a reference position that is predetermined as a position where the subject eye E can be photographed by the photographing optical system 300. When the head unit 602 is at the reference position, the positions where the reflected light from the cornea is received on the profile sensors 107 and 108 are predetermined. Therefore, the control unit 600 moves the head unit 602 a predetermined amount so that the reflected light from the cornea moves toward the predetermined position.

[0042] Next, the control unit 600 turns on the light source 300a (step S4). That is, the control unit 600 turns on the light source 300a for projecting ring light onto the anterior eye part in order to capture an image of the eye surface of the anterior eye part.

[0043] After turning on the light source 300a in step S4, the control unit 600 continuously captures images of the eye surface (step S5). That is, the control unit 600 controls the drive unit of the lens in the imaging optical system 300 using the light source 300a, moves at least one of the objective lens 303 and the imaging lens 305 in the optical axis direction to bring the eye surface into a focused state, and controls the two-dimensional imaging element 306 to perform imaging. For continuous imaging, for example, at the instruction of the examiner, the subject is asked to close the eyelids and then open the eyelids for a predetermined time, during which images of the eye surface are continuously captured. Alternatively, the subject is asked to open and close the eyelids (i.e., blink), and during that time, images of the eye surface are continuously captured. In this embodiment, the frame rate of the two-dimensional imaging element 306 is 60 fps, that is, the period for one frame is 1 / 60 second. As a result, images of the eye surface are continuously captured.

[0044] Note that the focused state only needs to be realized before the images are continuously captured. Also, the process for realizing the focused state may be various processes. For example, it may be realized by a phase difference detection method based on the imaging result of the two-dimensional imaging element 306, or a plurality of images may be captured while changing the position of the lens, and the lens may be moved in advance to the position where the focused state image is captured. When imaging is performed, the control unit 600 records the images output from the two-dimensional imaging element 306 in the memory 670.

[0045] Next, the control unit 600 displays the captured images in step S5 on the display unit 650 (step S6). That is, the control unit 600 displays the images captured in step S5 on the display unit 650 by the function of the display processing unit 600b. The display of the captured images on the display unit 650 is arranged and displayed along the time series. Alternatively, it is played and displayed as a moving image in the time series order. That is, the display on the display unit 650 is displayed as a still image or a moving image.

[0046] Next, the imaging of the ocular surface when the imaging mode is the first imaging mode will be described. Specifically, when it is negatively determined in step S2 described above, that is, when it is determined that the imaging mode is not the second imaging mode, it is determined whether the imaging mode is the first imaging mode (step S10).

[0047] If it is affirmatively determined in this step S10 that the imaging mode is the first imaging mode, the control unit 600 performs alignment in the XYZ directions (step S20). That is, the control unit 600 drives the head unit 602 in the three-dimensional directions of XYZ to perform alignment (positioning) with respect to the eye E to be examined. Since the specific content of the alignment is the same as the alignment in the second imaging mode described in step S3, detailed description thereof will be omitted.

[0048] Next, the control unit 600 turns on the light sources 301 and 302 for exciting fluorescein (fluorescent dye) (step S30). That is, the control unit 600 turns on the light source to capture an image of the ocular surface of the anterior eye segment.

[0049] After the light sources 301 and 302 are turned on in step S30, the control unit 600 continuously captures images of the ocular surface (step S40). That is, the control unit 600 controls the drive unit of the lens in the imaging optical system 300 using the light sources 301 and 302, moves at least one of the objective lens 303 and the imaging lens 305 in the optical axis direction to bring the ocular surface into a focused state, and controls the two-dimensional imaging element 306 to perform imaging. For continuous imaging, for example, at the instruction of the examiner, the subject is asked to close the eyelids and then open the eyelids for a predetermined time, and during that time, images of the ocular surface are continuously captured. Alternatively, the subject is asked to open and close the eyelids (i.e., blink), and during that time, images of the ocular surface are continuously captured. In this embodiment, the frame rate of the two-dimensional imaging element 306 is 60 fps, that is, the period for one frame is 1 / 60 second. As a result, images of the ocular surface are continuously captured.

[0050] Note that the focus state only needs to be achieved before the images are continuously captured. Also, the processes for achieving the focus state can be various processes. For example, it may be achieved by the phase difference detection method based on the imaging result of the two-dimensional imaging element 306, or a plurality of images may be captured while changing the position of the lens, and the lens may be moved in advance to the position where the in-focus image is captured. When the imaging is performed, the control unit 600 records the image output from the two-dimensional imaging element 306 in the memory 670.

[0051] Next, the control unit 600 displays the captured image in step S40 (step S50). That is, the control unit 600 displays the image captured in step S40 on the display unit 650 by the function of the display processing unit 600b. The display of the captured image on the display unit 650 is arranged and displayed along the time series. Alternatively, it is played and displayed as a moving image in the time series order. That is, the display on the display unit 650 is displayed as a still image or a moving image.

[0052] Next, the imaging of the ocular surface in the case of the third imaging mode where the imaging mode is ring imaging and imaging by fluorescence excitation will be described. Specifically, when it is negatively determined in step S10 described above, that is, when it is determined that the imaging mode is not the first imaging mode, since the imaging mode is not any of the first imaging mode and the second imaging mode, it becomes the third imaging mode.

[0053] Therefore, similar to the other modes described above, the control unit 600 performs alignment in the XYZ directions (step S100). That is, the control unit 600 drives the head unit 602 in the three-dimensional directions of XYZ to perform alignment (positioning) with respect to the eye to be examined E. Since the specific content of the alignment is the same as the alignment in the second imaging mode described in step S3, the detailed description thereof is omitted.

[0054] Next, the control unit 600 cooperatively controls the first shooting mode and the second shooting mode. Specifically, in the present embodiment, images of the eye surface are alternately shot in the first shooting mode and the second shooting mode for each predetermined frame. More specifically, to shoot an image of the eye surface in the second shooting mode, the control unit 600 turns on the light source 300a (i.e., the ring light source) (step S200) and continuously shoots the second shooting image, which is the image of the eye surface (step S300). That is, before performing the shooting in step S300 and the shooting in step S500 described later, the control unit 600 controls the driving unit of the lens to move at least one of the objective lens 303 and the imaging lens 305 in the optical axis direction to bring the eye surface into a focused state. The focused state only needs to be realized before the images are continuously shot. Also, the process for realizing the focused state may be various processes. For example, it may be realized by the phase difference detection method based on the shooting result of the two-dimensional imaging device 306, or a plurality of images may be shot while changing the position of the lens, and the lens may be moved in advance to the position where the image in the focused state is shot. When the focused state is realized, the control unit 600 controls the two-dimensional imaging device 306 to perform shooting. The lighting of the light source 300a and the shooting as described above are performed for one frame at 60fps. That is, in steps S200 and S300, the control unit 600 synchronizes the lighting of the light source 300a and the shooting by the two-dimensional imaging device 306, and controls the light source 300a and the two-dimensional imaging device 306 so that the lighting switching and the shooting are completed within a period of 1 / 60 second. When it is negatively determined in step S600 described later and returns to step S200, the control content of step S200 is to turn off the light sources 301 and 302, which are fluorescence excitation light sources, and turn on the light source 300a.

[0055] Next, in order to perform continuous shooting in the first shooting mode, the control unit 600 turns off the light source 300a and turns on the light sources 301 and 302 (i.e., the fluorescence excitation light sources) (step S400). That is, the control unit 600 performs switching control of the light sources in order to switch the shooting mode. After the control unit 600 switches the light sources, it shoots a first captured image, which is an image of the eye surface by fluorescence excitation (step S500). That is, the control unit 600 controls the two-dimensional image sensor 306 to perform shooting. Here too, the lighting of the light sources 301 and 302 and the shooting are performed in one frame at 60 fps. That is, in steps S400 and S500, the control unit 600 synchronizes the lighting of the light sources 301 and 302 and the shooting by the two-dimensional image sensor 306, and controls the light sources 301 and 302 and the two-dimensional image sensor 306 so that the lighting switching and the shooting are completed in a period of 1 / 60 second.

[0056] In these shootings, the shooting in the second shooting mode and the shooting in the first shooting mode are performed in a predetermined period after the same blink of the eye to be examined. Here, it is sufficient to obtain an image in a predetermined period after the blink. For example, it may be shot in a predetermined period after the subject opens the eyelids from a state where the eyelids are closed, or shooting may be performed over a period longer than the predetermined period, and an image shot in a predetermined period after the subject opens the eyelids from a state where the eyelids are closed may be extracted. Also, in these shootings, the state of the eyes is shot in the same state. The shooting interval between the image in the second shooting mode and the image in the first shooting mode is the period of one frame. In the present embodiment, the two-dimensional image sensor 306 is a sensor capable of shooting at 60 fps as described above, and the period of one frame is 1 / 60 second. Therefore, the image in the second shooting mode and the image in the first shooting mode are shot almost simultaneously. For this reason, it can be said that the eye to be examined shown in the image by ring shooting and the captured image by fluorescein staining is the same state of the eye to be examined.

[0057] FIG. 5 is an example in the case where imaging by ring projection and imaging by fluorescein staining are alternately performed. In the example shown in this FIG. 5, for each frame (that is, for each time), imaging by ring projection and imaging by fluorescein staining are alternately performed. In the example shown in this FIG. 5, although imaging by ring projection and imaging by fluorescein staining are alternately performed for each frame, that is, for every 1 / 60 second (in other words, at a ratio of 1:1), the ratio of imaging is not limited to this. For example, imaging by fluorescein staining may be performed two times (at a ratio of 1:2) for one time of imaging by ring projection. That is, within one second, imaging in the second imaging mode and imaging in the first imaging mode may be alternately switched at predetermined intervals.

[0058] Then, the control unit 600 repeatedly performs imaging in this second imaging mode and the first imaging mode for a predetermined time. That is, the group α of step S200 and step S300, and the group β of step S400 and step S500 are alternately executed, and imaging of the ocular surface image of the anterior eye part is performed until a predetermined time elapses.

[0059] Next, the control unit 600 determines whether imaging of the ocular surface image has been completed due to the elapse of a predetermined time (step S600). If it is determined negatively in this step S600, that is, if it is determined that the predetermined time has not elapsed, the process returns to step S200, and steps S200 to S500 are repeatedly executed until it is determined affirmatively in this step S600.

[0060] On the other hand, if it is determined affirmatively in step S600, that is, if it is determined that the predetermined time has elapsed, the control unit 600 acquires the ocular surface images taken in the second imaging mode along the time series, and the ocular surface images taken in the first imaging mode along the time series, respectively (step S700). That is, the control unit 600 acquires the images taken in each imaging mode arranged along the time series.

[0061] Next, the control unit 600 displays the captured image acquired in step S700 on the display unit 650 (step S800). That is, the control unit 600 separates the image captured in the second imaging mode and the image captured in the first mode by the function of the display processing unit 600b, and displays them on the display unit 650. The captured images displayed on the display unit 650 are arranged and displayed as still images along the time series, or are reproduced and displayed as a moving image in the time series order.

[0062] Next, the operation in the present embodiment will be described. As described above, in the present embodiment, when capturing an image of the ocular surface in the anterior segment of the eye E to be examined, it is possible to capture images in a plurality of imaging modes. Specifically, it is possible to capture images in a first imaging mode which is fluorescence excitation imaging, a second imaging mode which is ring imaging, and a third imaging mode which captures images in both ring imaging and fluorescence excitation imaging. In particular, by alternately performing imaging in the third imaging mode, that is, imaging by ring projection and imaging by fluorescein staining, it is possible to compare the same characteristic (or the same event) between a first captured image captured by fluorescein staining and a second captured image captured by ring projection. Therefore, it is possible to verify whether or not the measurement result obtained by fluorescein staining matches the measurement result obtained by ring projection.

[0063] When it is found that the measurement result obtained by fluorescein staining matches the measurement result obtained by ring projection, hereinafter, in principle, it is possible to operate so as to perform a diagnosis based on the second captured image captured by ring projection. Even in this case, when it is desired to perform a detailed diagnosis, the diagnosis may be performed based on the first captured image captured after fluorescein staining (the same applies hereinafter).

[0064] On the other hand, when the measurement results obtained by fluorescein staining do not match the measurement results obtained by ring projection, various operations can be performed. For example, when it is found that the imaging method in which accurate measurement is performed based on the measurement results obtained by fluorescein staining and the measurement results obtained by ring projection, an operation can be performed that prioritizes the imaging method capable of performing accurate measurement. Of course, even in this case, measurement may be performed using an imaging method that is not prioritized (the same applies hereinafter).

[0065] Also, conditions under which the measurement results obtained by fluorescein staining do not match the measurement results obtained by ring projection may be specified. For example, when there are cases where the measurement results match and do not match depending on the subject, in principle, for subjects whose measurement results match, diagnosis can be performed based on the second captured image captured by ring projection. When the measurement results do not match, an operation can be performed that prioritizes the imaging method capable of performing accurate measurement.

[0066] Also, when there are cases where the measurement results match and do not match depending on the symptoms of the anterior eye segment, when examining symptoms for which the measurement results match, in principle, diagnosis can be performed based on the second captured image captured by ring projection. When examining symptoms for which the measurement results do not match, an operation can be performed that prioritizes the imaging method capable of performing accurate measurement. In any case, in the present embodiment, accurate measurement is possible in the measurement of the ocular surface.

[0067] (3) Other embodiments: The above embodiments are examples for implementing the present invention, and various other embodiments can be adopted as long as the eye to be examined can be imaged by the first imaging mode and the second imaging mode. For example, the ophthalmic device is not limited to the configuration including the head portion and the main body portion as described above, and may be an ophthalmic device including various other elements.

[0068] In the above-described embodiment, when the control unit 600 performs imaging of the ocular surface using the third imaging mode that combines imaging by ring projection and imaging by fluorescein staining, after performing the control of group α in steps S200 and S300, it is configured to perform the control of group β in steps S400 and S500. However, the order of this control between group α and group β may be reversed. That is, after performing the control of group β in steps S400 and S500 (i.e., imaging by fluorescein staining), the control of group α in steps S200 and S300 (i.e., imaging by ring projection) may be performed.

[0069] Also, the captured image by ring projection and the captured image by fluorescein staining are not limited to images captured at a predetermined time after the same blink of the subject eye E, and may be images captured at a predetermined time after another blink. Even when the imaging by ring projection and the imaging by fluorescein staining are performed at different times, if these imaging operations are performed within an extremely short period (several seconds to a dozen or so seconds), it is considered that the state (characteristics) of the ocular surface of the same subject hardly changes. That is, even if the captured image by ring projection and the captured image by fluorescein staining are images captured at different times, it can be said that the subject eye shown in the captured image by ring projection and the subject eye shown in the captured image by fluorescein staining are subject eyes in the same state.

[0070] Also, the term "alternately switching the first captured image (captured image by fluorescein staining) and the second captured image (captured image by ring projection) every predetermined number of times" means that, in addition to switching between the first captured image and the second captured image one by one every 1 / 60 second, a predetermined arbitrary number of the first captured images (for example, two or three) may be acquired, and then a predetermined arbitrary number of the second captured images may be acquired. In other words, the control of switching between the light sources 301, 302 and the light source 300a is not limited to every 1 / 60 second, and may be performed at any timing.

[0071] In addition, in the above-described embodiment, the imaging control unit 600a performs imaging in the first imaging mode, the second imaging mode, and the third imaging mode, and controls the light sources 301, 302, and the light source 300a at that time. However, a control unit may be provided for each control content. Therefore, for example, a light source control unit for controlling the lighting and extinguishing of the light source may be provided separately.

[0072] Furthermore, the method of enabling a specific part of the eye to be imaged in the first imaging mode, the second imaging mode, and the third imaging mode is also applicable as an invention of a method. In addition, the ophthalmic apparatus and method as described above can be assumed to be realized as a single apparatus or as a part of an apparatus having a plurality of functions, and may include various aspects.

Description of Reference Numerals

[0073] 1... Ophthalmic apparatus, 100... Alignment optical system, 101... Light source, 102... Hot mirror, 103... Objective lens, 104... Hot mirror, 105... Lens, 106... Lens, 107... Profile sensor, 108... Profile sensor, 300... Imaging optical system, 300a... Light source, 301... Light source, 302... Light source, 303... Objective lens, 304... Dichroic mirror, 305... Imaging lens, 306... Two-dimensional imaging element, 307... Green filter, 400... Fixation optical system, 403... Relay lens, 404... Reflecting mirror, 500... Eye refractive power optical system, 501... Light source, 502... Condensing lens, 503... Mirror, 504... Mirror, 505... Parallel plane glass, 506... Hot mirror, 507... Lens, 508... Ring lens, 509... Two-dimensional imaging element, 510... Plane glass, 511... Plane glass, 512... Fixation mark, 513... Collimator lens, 514... Light source, 600... Control unit, 600a... Imaging control unit, 600b... Display processing unit, 601... Main body unit, 602... Head unit, 630... XYZ drive control unit, 640... Joystick, 650... Display unit, 660... Touch panel, 670... Memory, 680... Fixation mark control unit.

Claims

1. An excitation light source that excites fluorescence from a fluorescent dye instilled in the anterior eye segment of the eye to be examined, A projection unit that projects a plurality of rings onto the anterior eye segment, An imaging optical system that images the anterior eye segment, An imaging control unit that controls the imaging optical system to capture a plurality of first captured images that are images of the anterior eye segment illuminated by the excitation light source and a plurality of second captured images that are images of the anterior eye segment projected by the projection unit, The first captured image and the second captured image are images captured during a predetermined period after the same blink of the eye to be examined, An ophthalmic device.

2. An excitation light source that excites fluorescence from a fluorescent dye instilled in the anterior eye segment of the eye to be examined, A projection unit that projects a plurality of rings onto the anterior eye segment, An imaging optical system that images the anterior eye segment, An imaging control unit that controls the imaging optical system to capture a plurality of first captured images that are images of the anterior eye segment illuminated by the excitation light source and a plurality of second captured images that are images of the anterior eye segment projected by the projection unit, The imaging control unit, Receives a selection of any one of a first imaging mode for continuously capturing the first captured image, a second imaging mode for continuously capturing the second captured image, and a third imaging mode for continuously capturing the first captured image and continuously capturing the second captured image, and performs imaging corresponding to the selected mode. An ophthalmic device.

3. The first captured image and the second captured image are images captured during a predetermined period after another blink of the eye to be examined, The ophthalmic device according to claim 2.

4. The imaging control unit, Receives a selection of any one of a first imaging mode for continuously capturing the first captured image, a second imaging mode for continuously capturing the second captured image, and a third imaging mode for continuously capturing the first captured image and continuously capturing the second captured image, and performs imaging corresponding to the selected mode. The ophthalmic device according to claim 1.

5. The imaging control unit, Alternately switches between capturing the first captured image and capturing the second captured image at predetermined intervals. The ophthalmic device according to any one of claims 1 to 4.

6. Further comprising a display processing unit that separately displays the first captured image and the second captured image. The ophthalmic device according to any one of claims 1 to 5.

7. The display processing unit arranges and displays at least one of the plurality of first captured images captured continuously and the plurality of second captured images captured continuously in time series. The ophthalmic device according to claim 6.

8. The display processing unit reproduces and displays at least one of the plurality of first captured images captured continuously and the plurality of second captured images captured continuously as a moving image in chronological order. The ophthalmic device according to claim 6.

Images