JP2017099717A - Ophthalmic photographing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ophthalmic photographing apparatus with which a diaphanoscopic image can be captured with the effect of a corneal reflex bright point reduced in a simplified manner.SOLUTION: An ophthalmic photographing apparatus for photographing a subject eye comprises: projection means for projecting illumination light onto the subject eye; photographing means for photographing the anterior eye part of the subject eye including the crystalline lens illuminated with the illumination light projected by the projection means and reflected off the eyeground; and projection control means for projecting the illumination light from the projection means onto the subject eye in sequence with the incidence condition varied at each reception of a photographing start signal for photographing the anterior eye part. The ophthalmic photographing apparatus further comprises image processing means for synthesizing, by an image processing process, plural image information pieces captured by the photographing means using the illumination light projected in sequence with varied incident angles, thereby producing anterior eye part information from which the information of the cornea bright point has been eliminated.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to an ophthalmologic photographing apparatus that photographs a subject's eye.

  2. Description of the Related Art Conventionally, an ophthalmologic apparatus that performs transillumination imaging that can confirm the state of turbidity of a crystalline lens, for example, in order to determine the cause of a measurement error is known. In transillumination, the degree of opacity of the lens due to cataracts can be confirmed by irradiating the subject's eye with illumination light and observing (photographing) the anterior segment of the eye including the lens illuminated by the reflected light from the fundus. it can. Such transillumination imaging can obtain an anterior ocular segment image including a crystalline lens, but a corneal reflection bright spot is generated by illumination light, which makes it difficult to see the transillumination image. Conventionally, in an ophthalmologic photographing apparatus that can perform transillumination imaging, in order to reduce the influence of the corneal reflection bright spot, the corneal reflection bright spot formed on the eye to be examined is strictly aligned with the eye to be examined in the front-rear direction. The observation optical axis of the ophthalmologic imaging apparatus (imaging optical axis) is shifted with respect to the eye to be examined until the corneal reflection bright spot is not generated.

Japanese Patent Laid-Open No. 6-142044

  However, for example, when it is desired to confirm the turbid state of the lens in detail, even a small corneal reflection luminescent spot tends to be an obstacle. Further, for example, when performing observation / photographing with the optical axis shifted, the operation tends to be troublesome.

  An object of the present disclosure is to provide an ophthalmologic photographing apparatus capable of photographing a transillumination image in which the influence of the corneal reflection bright spot is suppressed without trouble in the transillumination image photographing.

In order to solve the above problems, the present invention is characterized by having the following configuration.
An ophthalmologic photographing apparatus for photographing a subject's eye includes an irradiating means for irradiating illumination light to the subject's eye, and a crystalline lens illuminated by light reflected from the fundus by the illuminating light irradiated by the irradiating means. An imaging means for imaging the anterior eye portion of the subject's eye, including a single imaging start signal for imaging the anterior eye portion, and illumination light from the irradiating means for the subject's eye A plurality of captured image information photographed by the photographing means by the illumination means sequentially irradiating in different incident states and the illumination light sequentially illuminated at different incident angles using image processing. Image processing means for obtaining anterior ocular segment image information from which corneal bright spot image information has been removed.

  According to the present disclosure, it is possible to provide an ophthalmologic photographing apparatus capable of photographing a transillumination image in which the influence of the corneal reflection bright spot is suppressed without trouble in the transillumination image photographing.

It is a schematic block diagram of the optical system of the fundus imaging apparatus of the present embodiment. It is a schematic block diagram of the control system of the fundus imaging apparatus of FIG. It is a flowchart explaining the flow of the whole imaging | photography. It is a flowchart concerning transillumination photography. 5 is a flowchart relating to image processing of a fundus image. It is a figure of a transillumination image. It is a figure of a fundus image. It is a figure explaining the input-output relationship of a signal. It is a figure explaining the image processing of this embodiment. It is a figure explaining the change of the picked-up image by the image processing of FIG. It is a figure explaining the image processing of the modification example.

  Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of an optical system of a fundus photographing apparatus 1 (ophthalmic photographing apparatus) according to the present embodiment. FIG. 2 is a schematic configuration diagram of a control system of the fundus imaging apparatus 1 of the present embodiment. Note that the fundus imaging apparatus 1 of the present embodiment may be called a non-mydriatic fundus camera.

  The optical system of the fundus imaging apparatus 1 of this embodiment includes a fundus illumination optical system 10, a fundus observation / imaging optical system 20, a transillumination projection optical system 30 (projection means), and an anterior ocular segment observation / transmission imaging. An optical system 40 (photographing means) is included. The fundus illumination optical system 10 of the present embodiment is used for illuminating the fundus of the subject's eye E. The fundus oculi observation / imaging optical system 20 of the present embodiment is used for observing and photographing the fundus oculi of the subject eye E. The transillumination projection optical system 30 of the present embodiment is used to illuminate the intermediate translucent body (vitreous body, crystalline lens, anterior chamber, cornea, etc.) of the subject's eye E from the fundus side. The anterior ocular segment observation optical system / transmission imaging optical system 40 of the present embodiment is used to capture a transillumination image of the subject's eye E or an anterior segment image of the subject's eye E. The fundus photographing apparatus 1 of the present embodiment further includes a fixation target presenting optical system 50. The fixation target presenting optical system 50 of the present embodiment is used for guiding the line of sight of the subject's eye E.

<Fundamental illumination optical system>
The fundus illumination optical system 10 of the present embodiment includes a photographing illumination optical system 10a (light projection means) and an observation illumination optical system 10b. The photographing illumination optical system 10a of the present embodiment is used to project photographing light onto the fundus of the subject's eye E. In the present embodiment, visible light is projected as photographing light. The observation illumination optical system 10b of the present embodiment is used to project observation light onto the fundus of the subject's eye E. In this embodiment, infrared light is projected as observation light.

  The photographing illumination optical system 10 a of this embodiment includes a photographing light source 91, a condenser lens 11, a ring slit 14, a relay lens 15, a black spot plate 16, a relay lens 17, a perforated mirror 18, and an objective lens 21. The photographing illumination optical system 10a of the present embodiment further includes a dichroic mirror 13. The photographing light source 91 of this embodiment is used as a light source for photographing light. The imaging light source 91 of this embodiment emits visible light. The imaging light source 91 of the present embodiment can emit flash light (in other words, flash light and pulsed light). A flash lamp, LED (white LED), or the like may be used as the imaging light source 91.

  The dichroic mirror 13 of the present embodiment is disposed between the condenser lens 11 and the ring slit 14. The dichroic mirror 13 of the present embodiment has a characteristic of transmitting light (visible light) from the photographing light source 91 and reflecting light (infrared light) from the observation light source 92. The ring slit 14 of the present embodiment is disposed at a position conjugate with the pupil of the subject's eye E. Note that the fundus imaging apparatus 1 of the present embodiment includes a light control unit for the amount of imaging light. The control unit 80 of the present embodiment can adjust the amount of light emitted from the photographing light source 91.

  The photographing light emitted from the photographing light source 91 strikes the ring slit 14 through the condenser lens 11 and the dichroic mirror 13 in this order. The photographing light that has passed through the opening of the ring slit 14 is reflected by the perforated mirror 18 through the relay lens 15, the black spot plate 16, and the relay lens 17 in this order. The photographing light reflected by the perforated mirror 18 is once condensed in a ring shape on the pupil of the eye E through the objective lens 21. The imaging light (ring shape) condensed on the pupil diffuses toward the fundus to illuminate the fundus. In this way, illumination of the fundus of the subject's eye E is performed with imaging light (visible light).

  The observation illumination optical system 10b of the present embodiment shares the optical system from the dichroic mirror 13 to the objective lens 21 with the photographing illumination optical system 10a. The observation illumination optical system 10 b of this embodiment includes an observation light source 92 and a condenser lens 12. The observation light source 92 of the present embodiment emits infrared light (center wavelength 880 nm). The observation light source 92 of this embodiment can emit continuous light. As the observation light source 92, an LED (infrared LED), a light bulb (such as a halogen lamp), or the like may be used. Note that the observation light emitted from the observation light source 92 is reflected by the dichroic mirror 13 via the condenser lens 12. The observation light reflected by the dichroic mirror 13 strikes the ring slit 14. Since the subsequent steps are the same as the above-described photographing light, description thereof is omitted.

<Fundation observation / fundus imaging optical system>
Next, the fundus oculi observation / imaging optical system 20 will be described. The fundus oculi observation / imaging optical system 20 of the present embodiment includes a fundus oculi imaging optical system 20a and a fundus oculi observation optical system 20b. The fundus photographing optical system 20a of the present embodiment is used to photograph the fundus of the subject eye E. The fundus oculi observation optical system 20b of this embodiment is used for observing the fundus oculi of the subject eye E. In the present embodiment, the fundus oculi observation means that combines the observation illumination optical system 10b and the fundus oculi observation optical system 20b can observe the fundus of the subject's eye E with observation light (infrared light). In the present embodiment, the fundus photographing unit combining the photographing illumination optical system 10a and the fundus photographing optical system 20a can photograph the fundus of the subject's eye E with photographing light (visible light).

  The fundus photographing optical system 20a of the present embodiment includes an objective lens 21, a photographing aperture 22, a focusing lens 23, an imaging lens 24, and a light receiving element 93. In the present embodiment, a photographing aperture 22 is disposed in the vicinity of the aperture of the perforated mirror 18. The photographing aperture 22 of the present embodiment is formed with a circular opening. In the present embodiment, the photographing optical axis L1 passes through the center of the opening of the photographing aperture 22. A moving mechanism 86 is connected to the focusing lens 23. The focusing lens 23 can be moved along the photographing optical axis L1 by a moving mechanism 86. The light receiving element 93 of this embodiment is disposed at a position conjugate with the fundus of the subject's eye E. The light receiving element 93 of the present embodiment is a two-dimensional image sensor. The light receiving element 93 of this embodiment has a sensitivity in the visible range. For example, a CMOS image sensor may be used for the light receiving element 93.

  Imaging light reflected from the fundus of the subject's eye E (in other words, light emitted from the fundus) is condensed on the light receiving element 93 through the objective lens 21, the imaging aperture 22, the focusing lens 23, and the imaging lens 24 in this order. To do. In this manner, photographing (imaging) of the fundus of the subject's eye E with photographing light (visible light) is performed. In other words, the fundus imaging apparatus 1 of the present embodiment can acquire a fundus image (see FIG. 7) of the subject eye E using the fundus imaging optical system 20a.

  Next, the fundus oculi observation optical system 20b will be described. The fundus photographing optical system 20a and the fundus observation optical system 20b of the present embodiment share an optical system from the objective lens 21 to the flip-up mirror 25. The fundus oculi observation optical system 20b of this embodiment includes a dichroic mirror 41, a flip-up mirror 25, a dichroic mirror 26, an imaging lens 27, and a light receiving element 94.

  The dichroic mirror 41 (wavelength selective mirror) of this embodiment is provided obliquely between the objective lens 21 and the perforated mirror 18. The dichroic mirror 41 is an optical path branching member. The dichroic mirror 41 of the present embodiment transmits light having a wavelength of 900 nm or less including a wavelength for fundus observation (center wavelength 880 nm), and light having a wavelength for transillumination photography and anterior segment observation (center wavelength 940 nm). It has a characteristic to reflect. Note that the dichroic mirror 41 of the present embodiment can also pass fixation target light (details will be described later).

  An insertion / removal mechanism 85 is connected to the dichroic mirror 41 of the present embodiment. The dichroic mirror 41 can be inserted into and removed from the photographing optical axis L1 by an insertion / removal mechanism 85. The dichroic mirror 41 of this embodiment is inserted on the photographing optical axis L1 during observation (when observing the fundus oculi, during anterior ocular segment observation, during transillumination photographing), and is photographed during fundus photographing under the control of the control unit 80. It is detached from the optical axis L1.

  An insertion / removal mechanism 87 is connected to the flip-up mirror 25 of the present embodiment. The flip-up mirror 25 can be inserted / removed on the photographing optical axis L <b> 1 by the insertion / removal mechanism 87. The flip-up mirror 25 of the present embodiment is inserted on the photographing optical axis L1 during observation (when observing the fundus, observing the anterior segment, or during transillumination) under the control of the control unit 80. It is detached from the photographing optical axis L1. The dichroic mirror 26 of the present embodiment has a characteristic of reflecting infrared light (fundus observation light) and transmitting visible light (fixation target light). The light receiving element 94 of this embodiment is disposed at a position conjugate with the fundus of the subject's eye E. The light receiving element 94 of the present embodiment is a two-dimensional image sensor. The light receiving element 94 of this embodiment has sensitivity in the infrared region. For example, a CMOS image sensor may be used for the light receiving element 94.

  The observation light reflected from the fundus of the subject's eye E (in other words, light emitted from the fundus) travels to the imaging lens 24 and is reflected by the flip-up mirror 25 in the same manner as the photographing light described above. The observation light reflected by the flip-up mirror 25 is reflected by the dichroic mirror 26 and then condensed on the light receiving element 94 via the imaging lens 27. In this way, observation (imaging) of the fundus of the subject's eye E with observation light (infrared light) is performed.

<Fixed target presentation optical system>
Next, the fixation target presenting optical system 50 will be described. The fundus oculi observation optical system 20b and the fixation target presentation optical system 50 of the present embodiment share an optical system from the objective lens 21 to the dichroic mirror 26. The fixation target presenting optical system 50 of the present embodiment includes a lens 28 and a fixation target light source 95. The fixation target light source 95 of the present embodiment is disposed at a position conjugate with the fundus of the subject eye E. The fixation target light source 95 of the present embodiment emits visible light (for example, green). The fixation target light source 95 of this embodiment is an LCD (liquid crystal display). Under the control of the control unit 80, a fixation target (for example, a filled circle) is displayed on the LCD. The fixation target presenting optical system 50 of the present embodiment can change the position of the fixation target presented to the subject eye E.

  The fixation target light (visible light) emitted from the fixation target light source 95 is reflected by the flip-up mirror 25 through the lens 28 and the dichroic mirror 26 in this order. The fixation target light reflected by the flip-up mirror 25 is condensed on the fundus of the eye E through the imaging lens 24, the focusing lens 23, the photographing aperture 22, the dichroic mirror 41, and the objective lens 21 in this order. In this way, the fixation target is presented to the subject's eye E (in other words, the fixation target image is projected onto the fundus of the subject's eye E).

<Transmission optical system>
Next, the transillumination projection optical system 30 (irradiation means) of this embodiment will be described. The transillumination projection optical system 30 of the present embodiment shares the objective lens 21 and the dichroic mirror 41 with the fundus oculi observation / imaging optical system 20 and the like. The transillumination projection optical system 30 of this embodiment includes a field lens 42, a half mirror 31, an aperture stop 32, a condenser lens 33, and a transillumination light source 97. Note that the transillumination light source 97 of the present embodiment is disposed at a position conjugate with the fundus of the subject's eye E. However, for example, the transillumination light source 97 may be arranged at a position conjugate with the pupil of the eye E of the subject.

  The transillumination light source 97 of this embodiment includes a plurality of light sources. Specifically, the transillumination light source 97 of the present embodiment includes a pair of light sources (a first transillumination light source 97a and a second transillumination light source 97b). Each of the first transillumination light source 97a and the second transillumination light source 97b is disposed at a position away from the optical axis L2 of the transillumination light projecting optical system 30, and each transillumination light source (97a, 97b). The illumination light emitted from the light is incident on the eye to be examined at different incident angles. Specifically, the first transillumination light source 97a and the second transillumination light source 97b are arranged at positions symmetrical with respect to the optical axis L2.

  The transillumination light source 97 of the present embodiment emits infrared light (central wavelength 940 nm). For example, as the illumination light source 97, an LED (light emitting diode), an SLD (super luminescent diode), or the like may be used. The aperture stop 32 of the present embodiment is disposed at a position conjugate with the pupil of the subject's eye E. In the present embodiment, the optical axis L2 passes through the center of the opening formed in the aperture stop 32. The aperture stop 32 of the present embodiment is used to limit the beam diameter of illumination light for transillumination (light from the transillumination light source 97) that passes through the pupil of the subject's eye E.

  The illumination light for transillumination emitted from the transillumination light source 97 is reflected by the dichroic mirror 41 through the condenser lens 33, the aperture stop 32, the half mirror 31, and the field lens 42 in this order. The illumination light for transillumination reflected by the dichroic mirror 41 is condensed on the fundus of the eye E through the objective lens 21. Note that the illumination light for transillumination in the present embodiment is emitted from the objective lens 21 as parallel light. In the transillumination photography according to the present embodiment, the illumination light reflected from the fundus serves as a secondary light source, and the intermediate translucent body of the subject's eye E is illuminated from the fundus side.

  As described above, the illumination light for transillumination onto the subject's eye E is projected. In the present embodiment, each of the first transillumination light source 97a and the second transillumination light source 97b emits a narrow luminous flux. For example, a diaphragm may be provided at a position conjugate with the cornea of the subject eye E of the transillumination projection optical system 30 to limit the cornea passage region (corneal passage position) of illumination light for transillumination. . In the present embodiment, the first transillumination light source 97a and the second transillumination light source 97b are alternately turned on during the transillumination shooting.

<Anterior segment observation and transillumination optical system>
Next, the anterior ocular segment observation / transmission imaging optical system 40 will be described. The anterior ocular segment observation / transmission imaging optical system 40 of the present embodiment shares the optical system from the objective lens 21 to the half mirror 31 with the transillumination projection optical system 30. The anterior ocular segment observation / transmission imaging optical system 40 of this embodiment includes a diaphragm 43, a relay lens 44, and a light receiving element 96. The light receiving element 96 of the present embodiment is disposed at a position conjugate with the anterior eye portion (for example, the pupil) of the subject's eye E. The light receiving element 96 of this embodiment is a two-dimensional image sensor. The light receiving element 96 of this embodiment has sensitivity in the infrared region. For example, a CMOS image sensor may be used for the light receiving element 96. Note that the fundus imaging apparatus 1 of this embodiment includes an observation light source 45 (center wavelength 940 nm) for anterior segment observation.

  Light from the eye E (light having a wavelength exceeding 900 nm) is reflected by the dichroic mirror 41 after passing through the objective lens 21. The light reflected by the dichroic mirror 41 is reflected by the half mirror 31 after passing through the field lens 42. The light reflected by the half mirror 31 is condensed on the light receiving element 96 through the stop 43 and the relay lens 44 in this order. In this embodiment, when observing the anterior segment of the subject's eye E, the observation light source 45 is turned on, and an anterior segment image of the subject's eye E is captured by the light receiving element 96. That is, in the present embodiment, an anterior ocular segment image of the subject's eye E is captured with infrared light by an anterior ocular segment observing means that combines the observation light source 45 and the anterior ocular segment observing / illuminating optical system 40. .

  On the other hand, in this embodiment, when a transillumination image of the subject eye E is taken, the transillumination light source 97 is turned on, and the transillumination image of the subject eye E is captured by the light receiving element 96. That is, in this embodiment, a transillumination image of the subject's eye E can be acquired by a transillumination imaging unit that combines the transillumination projection optical system 30 and the anterior ocular segment observation / transillumination imaging optical system 40. In the present embodiment, the anterior ocular segment observation and the transillumination photographing are performed in a state where the dichroic mirror 41 is inserted on the photographing optical axis L1.

  In the present embodiment, 940 nm is used as the wavelength of illumination light for transillumination. However, the wavelength of illumination light for illumination is not limited to this. For example, 880 nm may be used as the wavelength of illumination light for illumination. In this case, for example, the observation light source 92 is caused to emit infrared light having a center wavelength of 830 nm. The characteristic of the dichroic mirror 41 may be a characteristic that transmits light having a wavelength of 850 nm or less and reflects light having a wavelength exceeding 850 nm.

<Control system>
The control unit 80 of this embodiment will be described with reference to FIG. The control unit 80 of this embodiment includes a CPU 81, a RAM 82, a ROM 83, a nonvolatile memory 84, and the like. The CPU 81 controls each unit in the fundus imaging apparatus 1. The RAM 82 temporarily stores various information. The ROM 83 stores various programs, initial values, and the like. The nonvolatile memory 84 is a non-transitory storage medium that can retain stored contents even when power supply is interrupted. For example, a USB memory detachably attached to the control unit 80, a flash ROM incorporated in the control unit 80, or the like may be used as the nonvolatile memory 84. The value of the parameter related to photographing of the fundus photographing apparatus 1 may be stored in the nonvolatile memory 84. The control unit 80 of the present embodiment stores the fundus image in the nonvolatile memory 84 (storage means). Specifically, the control unit 80 of the present embodiment is a storage control unit, and as an example, stores the fundus image and the opacity information in association with each other in the storage unit (nonvolatile memory 84 or the like). As the storage means, the RAM 82 or another state holding medium (for example, a hard disk) may be used. An information processing apparatus (such as a personal computer) connected to the fundus imaging apparatus 1 by priority or wirelessly may be used as the storage unit.

  The control unit 80 of this embodiment includes a transillumination light source 97 (first transillumination light source 97a, second transillumination light source 97b), light receiving element 96, insertion / removal mechanism 85, moving mechanism 86, light receiving element 94, fixation target. A light source 95, an insertion / removal mechanism 87, a light receiving element 93, an observation light source 92, an imaging light source 91, a monitor 88 (display means), a switch unit 89, and an I / F unit 98 are connected. The control unit 80 of this embodiment has a function as display control means for controlling the display content of the monitor 88. The control unit 80 of the present embodiment displays a fundus image (captured image, observation image), an anterior ocular segment observation image, a transillumination image, and the like of the subject's eye E on the monitor 88. The switch unit 89 of this embodiment is an operation input unit. The switch unit 89 of the present embodiment accepts the examiner's operations such as switching of observation images (anterior ocular segment observation image, fundus observation image) to be displayed on the monitor 88, imaging start, and cataract mode selection. The control unit 80 according to the present embodiment can transfer a captured image (fundus image of the subject's eye E) or the like to the outside of the fundus imaging apparatus 1 using the I / F unit 98.

  Note that the control unit 80 of the present embodiment is an image processing unit that performs image processing on a captured image (fundus image). In addition, the control unit 80 according to the present embodiment is an image processing unit that combines a plurality of illumination images using image processing. The control unit 80 of the present embodiment is an irradiation control unit that controls the transillumination light source 97 in order to sequentially irradiate the illumination light for transillumination on the subject's eye E at different incident angles.

<Photographing the subject's eyes>
Next, with reference to FIG. 3, imaging of the eye E (transmission imaging and fundus imaging) using the fundus imaging apparatus 1 of the present embodiment will be described. The examiner operates a joystick (not shown) while observing the anterior ocular segment observation image displayed on the monitor 88 to align the optical system of the fundus imaging apparatus 1 with the subject's eye E. When the alignment to the subject eye E is substantially completed, the examiner operates the switch unit 89 to switch the display on the monitor 88 to the fundus observation image. The examiner performs precise alignment with the subject eye E while observing the fundus observation image displayed on the monitor 88. The examiner operates the switch unit 89 to appropriately change the fixation target presentation position (guidance of the fundus region to be photographed), focusing by moving the focusing lens 23, and the like.

  Next, after aligning the optical system of the fundus photographing apparatus 1 with the fundus of the subject's eye E, the examiner operates the switch unit 89 to start photographing. When the photographing start operation is performed, the switch unit 89 issues a photographing start signal (trigger signal) (step S101). When the control unit 80 detects the imaging start signal, it starts the transillumination imaging (step S102). Note that the control unit 80 turns off the anterior light source observation (alignment) observation light source 45 immediately before starting the transillumination photographing.

  A transillumination image (transmission image) of this embodiment will be described. The light projected on the fundus by the transillumination projection optical system 30 (irradiation means) is reflected by the fundus and illuminates the intermediate translucent body of the eye E from the fundus. The transillumination image in the case where the intermediate translucent body of the subject's eye E is not turbid is bright in the pupil and easily captured. On the other hand, in the transillumination image in the case where the intermediate translucent body of the subject's eye E is turbid, the turbid portion in the pupil (a part or the whole in the pupil) is dark and easily appears. Note that the region outside the pupil appears dark because the light from the fundus is attenuated by the iris.

  FIG. 4 and FIG. 6 will be used together to explain the transillumination shooting of this embodiment in detail. In addition, although the cloudy location is shown by the hatching area | region in FIG. 6, it is an illustration to the last. For example, the entire intermediate light transmitting member may become cloudy as the intermediate light transmitting member becomes cloudy.

  In step S201, the control unit 80 turns on the first transillumination light source 97a (turns off the second transillumination light source 97b). Next, in step S202, the control unit 80 receives the output signal of the light receiving element 96 and obtains a first transillumination image (see FIG. 6A). Note that a corneal bright spot image (Purkinje image) by light emitted from the first transillumination light source 97a is superimposed on the first transillumination image. Next, in step S203, the control unit 80 turns on the second transillumination light source 97b (the first transillumination light source 97a is turned off). Next, in step S204, the control unit 80 receives the output signal of the light receiving element 96 and obtains a second transillumination image (see FIG. 6B). In addition, the corneal bright spot image (Purkinje image) by the light from the light emitted from the second transillumination light source 97b is superimposed on the second transillumination image.

  Next, in step S205, the control unit 80 combines the first transillumination image and the second transillumination image by image processing to generate a composite image (see FIG. 6C). Specifically, the control unit 80 detects a region S1 in which a corneal bright spot image is reflected from the first transillumination image. Next, the control unit 80 cuts out image data in the region S2 from the second transillumination image. Note that the region S2 is a region corresponding to the region S1. Next, the control unit 80 rewrites the data in the region S1 with image data cut out from the second transillumination image. In this way, the control unit 80 of the present embodiment generates a composite image (one transillumination image). In the composite image generated by the image processing, superimposition of unnecessary information (corneal bright spot image) is suppressed.

  That is, the fundus imaging apparatus 1 of the present embodiment irradiates with the transillumination projection optical system 30 (irradiation means) for irradiating the subject eye E with illumination light and the transillumination projection optical system 30. An anterior ocular segment observation / transmission imaging optical system 40 (imaging means) that images the anterior ocular segment of the subject's eye E including the crystalline lens illuminated by the reflected light from the fundus of the illuminating light is provided. In addition, the control unit 80 of the present embodiment receives a single imaging start signal for imaging the anterior segment, and the illumination light from the transillumination projection optical system 30 is different for each eye E. Image processing is performed for a plurality of transillumination images (captured image information) photographed by the anterior ocular segment observation / transillumination imaging optical system 40 with illumination light sequentially irradiated at different incident angles, respectively. Is used to generate a transillumination image (anterior segment image information) from which the corneal bright spot image information has been removed. As a result, for example, it is possible to shoot a transillumination image that suppresses the influence of unnecessary light such as a corneal reflection luminescent spot without trouble in the transillumination image capturing.

  In addition, when irradiating illumination light with a different incident angle, for example, the illumination light may be incident with a different incident angle with respect to the visual axis of the eye to be inspected by fixation. Moreover, when irradiating illumination light with a different incident angle, the incident angle may be changed by driving the transillumination projection optical system 30, for example. More specifically, a plurality of illumination light sources may be provided, or the illumination light sources may be moved. Moreover, you may move the aperture stop arrange | positioned in the optical path.

  For example, the transillumination projection optical system 30 of the fundus imaging apparatus 1 of the present embodiment is a first transillumination light source provided so that illumination light is incident on the subject eye E at different incident angles. 97a and a second transillumination light source 97b. In response to the imaging start signal, the control unit 80 sequentially controls lighting of the first transillumination light source 97a and the second transillumination light source 97b. Thereby, for example, after performing the transillumination by shifting the optical axis, it is possible to suppress the trouble of realigning the apparatus and the eye to be examined in order to perform fundus imaging.

  In the present embodiment, two transillumination light sources 97 (first transillumination light source 97a and second transillumination light source 97b) are alternately turned on to obtain two transillumination images. However, the number of transillumination light sources may be three or more, and three or more transillumination images may be acquired. Further, for example, the aperture of the aperture stop disposed between the subject eye E and the subject eye E is displaced so that light (illumination light for transillumination) emitted from one transillumination light source is applied to the subject eye E. The projection angle (projection condition) may be changed.

  The method of irradiating the illumination light in different incident states is not limited to the method of irradiating the illumination light to the subject eye E at different incident angles, and the illumination light may be irradiated at different incident positions. Good. In this case, for example, the illumination light may be irradiated at a different incident position with respect to the corneal apex position. As a configuration for changing the incident position, for example, an alignment guiding unit may be used. More specifically, a plurality of transillumination images may be acquired by changing the positional relationship between the subject's eye E and the optical system of the fundus photographing apparatus 1 by the alignment guiding means. For example, the fundus imaging apparatus 1 may include automatic alignment means (alignment guidance means) that automatically aligns the optical system of the fundus imaging apparatus 1 with the subject's eye E. In this case, the control unit controls the automatic alignment means to change the alignment position of the optical system with respect to the eye E between the first transillumination image acquisition and the second transillumination image acquisition. You can shoot automatically. The control unit may generate a composite image similar to that of the present embodiment using the acquired two transillumination images. In this case, one illumination light source may be provided. Of course, as in the present embodiment, a plurality of illumination light sources may be provided, and a plurality of illumination images may be acquired while alternately lighting. Note that the mode of the alignment guiding means is not limited to this. What is necessary is just to be able to change the positional relationship between the subject's eye E and the optical system of the fundus photographing apparatus 1 when acquiring a plurality of transillumination images by the alignment guiding means. In other words, it suffices that the illumination light for transillumination photographing can be sequentially irradiated to the subject's eye E at different incident positions by the alignment guiding means.

  In the present embodiment, one transillumination image is generated from two transillumination images. However, a single transillumination image may be generated from three or more transillumination images. In the present embodiment, the first transillumination light source 97a and the second transillumination light source 97b are arranged at positions symmetrical with respect to the optical axis L2. However, a plurality of light sources may be arranged asymmetrically with respect to the optical axis L2. The transillumination light source 97 is disposed on the light receiving element 93 side of the perforated mirror 18, and the light emitted from the transillumination light source 97 passes through the opening of the perforated mirror 18 and is projected to the subject's eye E. May be lighted. In the present embodiment, illumination light for transillumination is projected through the objective lens 21, but illumination light for transillumination may be projected without passing through the objective lens 21.

  Returning to FIG. In step S103, the control unit 80 performs fundus photography. Specifically, the control unit 80 turns on the imaging light source 91 after retracting the dichroic mirror 41 and the flip-up mirror 25 from the imaging optical axis L1. Next, the control unit 80 obtains an output signal of the light receiving element 93 and obtains a fundus image (color fundus image) of the eye E of the subject. Next, in step S104, the control unit 80 analyzes the composite image (transmission image) generated in step S102. Specifically, the control unit 80 analyzes the transillumination image and obtains information such as the size of the turbid portion, the turbid concentration, and the brightness of the intermediate translucent body. You may analyze the pigmentation to an intermediate translucent body. In the analysis, WHO classification (cataract grade), Emery-Little classification, or the like may be used. For example, the degree of turbidity (five levels) of the intermediate light transmitting body may be used as the analysis result.

  Next, in step S <b> 105, the control unit 80 stores the fundus image acquired in step S <b> 103 and the analysis result (turbidity information) in step S <b> 104 in association with each other in the nonvolatile memory 84. Next, in step S <b> 106, the control unit 80 displays a fundus image and a transillumination image (composite image) on the monitor 88. The examiner observes the fundus image and the like displayed on the monitor 88. Note that only the fundus image may be displayed on the monitor 88. In addition, the analysis result of step S104 (for example, the degree of turbidity of the subject eye E) may be displayed together with the fundus image. Note that the timing of the transillumination shooting is not limited to the timing shown in step S102. For example, transillumination may be performed during alignment with the subject's eye E (before input of an imaging start signal) or after fundus imaging.

<Image processing of fundus image>
Next, image processing of a fundus image executed by the control unit 80 of the fundus imaging apparatus 1 of the present embodiment will be described with reference to FIG. When checking the fundus image in consideration of the opacity of the intermediate translucent body, the examiner operates the switch unit 89 to switch the display mode of the captured image from the normal display mode to the cataract mode. In step S301, the control unit 80 monitors the output signal of the switch unit 89 and determines the display mode selection state. If the control unit 80 determines that the cataract mode is selected, the process proceeds to step S302. In step S302, the control unit 80 reads the fundus image (and opacity information) from the nonvolatile memory 84, and performs image processing on the captured image.

  The image processing executed by the control unit 80 in step S302 will be described with reference to FIGS. FIG. 8 is a diagram for explaining the flow of data related to image processing according to the present embodiment. FIG. 9 is an explanatory diagram of image processing performed by the control unit 80 of the present embodiment. FIG. 10 is a diagram for explaining changes in fundus image data by image processing according to the present embodiment.

  The control unit 80 according to the present embodiment receives fundus image data IMG and opacity information data INF, and outputs fundus image data IMG ′ (see FIG. 8). The fundus image data IMG and the fundus image data IMG ′ of the present embodiment are composed of 3000 × 4000 pixels. Each pixel has 256 gradations (gradation value 0 to gradation value 255) of R / G / B.

  In the image processing of this embodiment, an image signal of 256 gradations is input, and an image signal of 256 gradations corresponding to the input signal is output. That is, gradation conversion of the image signal is performed. 9 indicates the input signal (fundus image data IMG) of the control unit 80, and the vertical axis of FIG. 9 indicates the output signal (fundus image data IMG ') of the control unit 80. Note that tone conversion using the same tone conversion characteristics is performed for each of R / G / B. A dotted line indicated by a symbol NOR in FIG. 9 illustrates a case where the control unit 80 does not perform gradation conversion (that is, a 1: 1 input / output relationship). In FIG. 9, solid lines and dotted lines indicated by reference numerals U1 to U3 exemplify gradation conversion characteristics when the control unit 80 performs gradation conversion. The gradation conversion characteristics shown in FIG. 9 are shown when the gamma characteristics of the fundus image data are γ = 1.0. The gradation conversion characteristics may be appropriately changed according to the gamma characteristics of the fundus image data.

  The control unit 80 of the present embodiment performs gradation conversion (contrast adjustment) according to the degree of opacity of the intermediate translucent body of the subject's eye E. Specifically, the control unit 80 of the present embodiment changes the input / output characteristics according to the degree of turbidity of the intermediate translucent body of the subject's eye E. For example, the control unit 80 uses the gradation conversion characteristic indicated by the symbol U1 for mild turbidity, and uses the gradation conversion characteristic indicated by the symbol U2 for moderate turbidity. In the case of severe turbidity, the gradation conversion characteristic indicated by the symbol U3 is used. The control unit 80 of the present embodiment performs image processing that increases the contrast of the fundus image as the degree of opacity of the subject's eye E increases. In other words, the control unit 80 of the present embodiment changes parameters used for image processing in accordance with the degree of opacity of the subject eye E.

  FIG. 10 illustrates the characteristics of the fundus image data when image processing is performed using the tone conversion characteristics of the symbol U3 (see FIG. 9). 10A is a histogram of fundus image data IMG (fundus image before image processing), and FIG. 10B is a histogram of fundus image data IMG ′ (fundus image after image processing). The horizontal axis in FIG. 10 indicates the gradation value (value range: 0 to 255), and the vertical axis in FIG. 10 indicates the number of pixels. 10A and 10B both show the brightness of the fundus image.

  Comparing before image processing (FIG. 10A) and after image processing (FIG. 10B), the number of pixels having higher gradation values increases after image processing. In other words, the distribution of gradation values is expanded by performing image processing. That is, the contrast of the fundus image is enhanced by performing the image processing. For example, by performing contrast enhancement in consideration of the opacity information (the degree of turbidity) of the subject eye E, it is possible to suppress the saturation of the fundus image gradation. Further, by performing contrast enhancement in consideration of the opacity information of the subject's eye E, it is possible to suppress excessive contrast enhancement, insufficient contrast enhancement, and the like.

  Returning to FIG. In step S <b> 303, the control unit 80 displays the captured image (fundus image data IMG ′) on which image processing has been performed on the monitor 88. The examiner observes the fundus image displayed on the monitor 88. As described above, image processing is performed on the fundus image (fundus image data IMG) in consideration of the opacity information of the intermediate translucent body of the eye E of the subject. In the present embodiment, image processing considering the opacity information (the degree of turbidity) of the intermediate translucent body is performed on the captured image once stored. The examiner can select the execution of the image processing in consideration of the opacity information of the intermediate translucent body after photographing the eye E of the subject. That is, the examiner selectively displays the fundus image (fundus image data IMG) in the normal mode and the fundus image (fundus image data IMG ′) in the cataract mode after photographing the eye E ( Observation). Note that the captured image (fundus image data IMG ′) subjected to image processing may be stored in a storage unit such as the nonvolatile memory 84.

  The image processing shown here is only an example. It is only necessary to perform image processing on the fundus image (fundus image data) in consideration of the opacity information of the intermediate translucent body of the eye E of the subject. For example, gradation conversion for a specific color (for example, red) included in the fundus image may be performed as image processing for the fundus image. In consideration of the opacity information of the intermediate translucent body of the subject's eye E, color conversion, hue conversion, and the like may be performed as image processing for the fundus image. Image processing for changing the brightness (brightness) of the entire captured image may be performed.

<Transformation example>
Next, a fundus imaging apparatus of a modification example will be described using FIG. The fundus photographing apparatus of the modification example has a mechanism (shape changing means) that can change the ring width of the ring slit 14 and changes the projection shape of the photographing light at the time of photographing by changing the ring width of the ring slit 14. And stores the shape information of the ring slit 14 in association with the captured image. For example, when the fundus photographing apparatus 1 can switch the shape of the ring slit 14 (that is, when the fundus photographing apparatus includes a shape changing unit for the ring slit 14), the control unit 80 uses the ring slit 14 used for fundus photographing. Is stored in the nonvolatile memory 84 in association with the captured image. The control unit 80 inputs the captured image and the ring slit shape information, and performs image processing on the captured image in consideration of the ring slit 14 shape information.

  FIG. 11 is a diagram for describing image processing for a captured image, which is executed by the control unit 80 of the fundus imaging apparatus of the modification example. The control unit 80 takes into consideration that the shape of the ring slit 14 is for a small pupil (large opening), and is an area having a shooting field angle of 35 ° to a shooting field angle of 45 ° (shown by hatching in FIG. 11). ) To emphasize the contrast. For example, if a flare is superimposed on the fundus image, the fundus image tends to be unclear. In the modification example, image processing is performed on the captured image in consideration that the flare is easily superimposed on the periphery of the fundus image by the ring slit 14 for the small pupil. This makes it easier for the examiner to observe the state of the periphery of the fundus image. Of course, the opacity information and the information related to the shape of the ring slit may be stored in association with the captured image. That is, you may combine with the image processing which considered the degree of opacity of the subject eye E.

  As described above, the fundus imaging apparatus 1 of the present embodiment acquires the opacity information of the imaging means for capturing the fundus image by imaging the fundus of the subject eye E and the intermediate translucent body of the subject eye E. Turbidity information acquisition means, and storage means for storing the fundus image and the opacity information in association with each other. Thereby, for example, when performing a diagnosis using a fundus image of the subject's eye E, the opacity of the intermediate light transmitting body of the subject's eye E can be considered.

  Further, the fundus imaging apparatus 1 of the present embodiment includes an image processing unit that executes image processing of a fundus image. The image processing means executes contrast adjustment according to the degree of turbidity based on the turbidity information as image processing. Thereby, for example, it is easy to perform appropriate image processing on the fundus image. Therefore, even if the intermediate translucent body is cloudy, it becomes easy to observe the affected area, blood vessels, and the like.

  In addition, the fundus imaging apparatus of the modification example includes a light projecting unit that projects imaging light onto the fundus of the subject's eye E, and a shape changing unit that changes the projection shape of the imaging light. The storage unit stores information related to the projection shape in association with the fundus image. The image processing means executes contrast adjustment using information regarding the projection shape as image processing. Thereby, for example, it becomes easy to observe the fundus of the subject's eye E even under a light projection condition in which unnecessary light is easily superimposed on the fundus image.

  Note that the fundus imaging apparatus 1 of the present embodiment performs acquisition of the fundus image and turbidity information and image processing of the fundus image. However, for example, the fundus imaging apparatus 1 may only acquire (and store associated information) the fundus image and opacity information, and an information processing terminal such as a personal computer may perform image processing of the fundus image. Of course, you may use only the image process with respect to the fundus image of this embodiment. That is, the first step of inputting the fundus image of the subject's eye by being executed by the processor of the information processing device (fundus photographing device, personal computer, etc.) and the opacity of the intermediate translucent body of the subject's eye A second step of inputting information, a third step of executing contrast adjustment according to the degree of turbidity based on the opacity information on the fundus image as image processing, and outputting (storing, transferring, Only the ophthalmologic information processing program that causes the information processing apparatus to execute the fourth step (display or the like) may be used. In the present embodiment, color photographing is performed as fundus photographing. However, fluorescence imaging (for example, spontaneous fluorescence imaging) may be performed as fundus imaging.

  In the present embodiment, the transillumination image of the subject's eye E is taken, and the opacity information of the intermediate translucent body is acquired. However, the method of acquiring turbidity information is not limited to this. For example, the laser light may be converged and projected toward the crystalline lens, and the scattered light of the laser light by the molecules inside the crystalline lens may be detected (see, for example, JP-A-08-206067). Further, for example, the anterior segment of the subject's eye E may be photographed based on the principle of Scheinproof (see, for example, Japanese Patent Laid-Open No. 04-096730). Further, for example, the fundus image observed with infrared light may be analyzed (for example, the density difference between the blood vessel and other fundus sites) to obtain the opacity information of the intermediate translucent body.

  In the present embodiment, a fundus camera is used as the fundus photographing apparatus 1. However, for example, the fundus imaging apparatus may be an SLO (scanning laser ophthalmoscope). The fundus image for image processing is not limited to a planar image. For example, the fundus image subjected to image processing may be a tomographic image. That is, the fundus imaging apparatus may be an OCT (optical coherence tomography). The fundus imaging apparatus may store the fundus image and the opacity information in association with each other. Further, the fundus imaging apparatus or the fundus imaging system may perform contrast adjustment according to the degree of turbidity based on the opacity information as image processing.

  The transillumination imaging (see FIGS. 4 and 6) shown in the present embodiment may be performed by an ophthalmologic apparatus other than the fundus imaging apparatus. For example, such transillumination may be performed by an ophthalmologic photographing apparatus such as an eye refractive power measuring apparatus. It is only necessary to continuously perform transillumination imaging with different light projection conditions on the subject's eye E, and to generate a composite image (transillumination image) in which superimposition of unnecessary light (corneal reflected light or the like) is suppressed.

  It should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1: fundus imaging apparatus 10: fundus illumination optical system 20: fundus observation / imaging optical system 30: transillumination projection optical system 40: anterior ocular segment observation / transillumination optical system 80: control unit 97a: first transillumination Light source 97b: second transillumination light source

Claims (4)

Irradiating means for irradiating the subject's eyes with illumination light;
Imaging means for imaging the anterior eye portion of the subject's eye including a crystalline lens illuminated by reflected light from the fundus of the fundus with the illumination light irradiated by the irradiation means;
An irradiation control means for receiving a single imaging start signal for imaging the anterior eye part and sequentially irradiating illumination light from the irradiation means to the subject's eyes in different incident states;
An anterior ocular segment image in which a plurality of captured image information captured by the imaging means with illumination light sequentially irradiated at different incident angles is combined using image processing to remove corneal bright spot image information Image processing means for obtaining information;
An ophthalmologic photographing apparatus comprising: An ophthalmologic photographing apparatus according to claim 1 is provided.
The irradiation means has a first light source and a second light source provided so that the illumination light is incident on the subject's eye at the different incident angles, and the irradiation control means outputs the imaging start signal. An ophthalmologic photographing apparatus characterized by receiving and sequentially controlling lighting of the first light source and the second light source. The ophthalmologic photographing apparatus according to claim 1 or 2,
The ophthalmologic photographing apparatus, wherein the image processing means causes the display means to display the anterior ocular segment image information obtained by the image processing as a transillumination image. The ophthalmologic photographing apparatus according to any one of claims 1 to 3,
The irradiation control means receives a single imaging start signal for imaging the anterior segment and sequentially irradiates illumination light from the irradiation means to the subject's eyes at different incident angles. Ophthalmic imaging device.