JP2015195875A - Eyeground imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To acquire a preferable fluorescent eyeground image in a composite device of an OCT and an eyeground camera.SOLUTION: An eyeground imaging device comprises: a barrier filter for penetrating fluorescence from an eyeground which is excited by fluorescent excitation light, and cutting light of a wavelength other than the fluorescence; a first imaging optical path for introducing reflectance and fluorescence from the eyeground by an imaging light source to a first imaging element; a second imaging optical path for introducing light from the eyeground by an observation light source to a second imaging element; and a wavelength separation member for branching the first and second imaging optical paths. The barrier filter penetrates the fluorescence from the subject eyeground, in which the fluorescence includes first light shorter than λ=700nm, and second light longer than λ=700nm and having a wavelength shorter than that of the eyeground observation light. In the wavelength separation member, wavelength selection characteristics are set so as to introduce the eyeground reflectance by the imaging light source and the fluorescence including the first light and second light to the first imaging element, and so as to introduce the eyeground observation light by the observation light source to the second imaging element.

Description

  The present invention relates to a fundus imaging apparatus for imaging the fundus of a subject's eye.

2. Description of the Related Art Conventionally, an ophthalmic optical coherence tomography (OCT) using low-coherent light or the like is known as an ophthalmologic apparatus that can take a tomographic image of an eye to be examined non-invasively.

  Further, a combined apparatus of the OCT and the fundus camera has been proposed (see Patent Documents 1 and 2). By the way, in the apparatus of Patent Document 2, light having a wavelength included in the range of 800 nm to 900 nm is used as the signal light from the OCT unit, and light having a wavelength included in the range of 400 nm to 700 nm is used as the observation light source. As a photographing light source, light having a wavelength included in the range of 700 nm to 800 nm is used.

  Therefore, a dichroic mirror is provided in the optical path of the photographing optical system of Patent Document 2, and this dichroic mirror has illumination light having a wavelength in the visible region from the illumination optical system (wavelength of about 400 nm output from the observation light source). ˜700 nm visible light) is transmitted, and illumination light having a wavelength in the near infrared region (near infrared light having a wavelength of about 700 nm to 800 nm output from the imaging light source) is reflected.

JP 2013-056274 A JP 2007-181631 A

  However, in the case of a dichroic mirror, it is difficult to observe or take a fundus image of both light having a wavelength shorter than λ = 700 nm and light having a wavelength longer than λ = 700 nm. As a result, in the case of taking a fluorescent image of the fundus of the eye to be examined, it may not be sufficient as acquired information.

  In view of the above-described problems of the prior art, an object of the present invention is to provide a fundus imaging apparatus capable of acquiring a good fluorescent fundus image in a combined apparatus of an OCT and a fundus camera.

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

A fundus illumination optical system for illuminating the subject's fundus with illumination light of at least any one of the photographing light source and the observation light source,
A fundus photographing optical system for photographing a front image of the fundus oculi illuminated by the illumination light, comprising a first image sensor for photographing the fundus and a second image sensor for observing the fundus The system,
An OCT optical system for obtaining a tomographic image of the fundus of the eye to be examined using a technique of optical interference;
An exciter filter that is detachably disposed in the optical path of the fundus illumination optical system, transmits fluorescence excitation light from light from the imaging light source, and cuts light of a wavelength other than the fluorescence excitation light;
A barrier filter that is detachably disposed in the optical path of the fundus imaging optical system, transmits fluorescence from the fundus excited by the fluorescence excitation light, and cuts light of a wavelength other than the fluorescence;
A first imaging optical path that is disposed in the optical path of the fundus imaging optical system and guides reflected light and fluorescence from the fundus to be examined by the imaging light source to the first image sensor, and from the fundus to be examined by the observation light source A wavelength separation member for branching the second imaging optical path for guiding the light of the second to the second imaging device;
With
The barrier filter includes a first light shorter than λ = 700 nm and a second light longer than λ = 700 nm and shorter in wavelength than the fundus observation light by the observation light source. A barrier filter that transmits fluorescence;
The wavelength separation member guides the fundus reflection light from the imaging light source and fluorescence including the first light and the second light to the first image sensor, and converts the fundus observation light from the observation light source to the second light source. The wavelength selection characteristic is set so as to lead to the imaging element.

It is the schematic which shows the external appearance of the fundus imaging apparatus which concerns on a present Example. It is a figure which shows the optical system and control system of the fundus imaging apparatus which concerns on a present Example. It is a figure which shows an example of the screen displayed on the display part which concerns on a present Example. It is an example when the anterior ocular segment image imaged by the image sensor is displayed on the display unit. It is an example when the fundus image imaged by the image sensor is displayed on the display unit. It is a block diagram which shows the control system which concerns on a present Example. It is a figure explaining the alignment detection with respect to a to-be-tested eye. It is a figure which shows an example of the wavelength characteristic of the optical system of the fundus imaging apparatus concerning this embodiment.

  Exemplary embodiments of the present invention will be described with reference to the drawings. In this embodiment, the depth direction of the eye to be examined is the Z direction (optical axis L1 direction), the horizontal component on the plane perpendicular to the depth direction (the same plane as the face of the subject) is the X direction, and the vertical direction. The component is described as the Y direction.

<Overview>
<Optical system>
The apparatus 1 includes an objective lens 25, a perforated mirror (hall mirror) 22, a fundus illumination optical system (hereinafter referred to as illumination optical system) 10, a fundus photographing optical system (hereinafter referred to as photographing optical system) 30, and interference optics. System (OCT optical system) 200 (see FIG. 2).

  For example, the objective lens 25 may be disposed in front of the eye to be examined. The perforated mirror 22 may include, for example, an opening 22a and a mirror 22b. The opening 22a may be formed at the center of the mirror 22b or may be arranged at an eccentric position. The opening 22a may have a configuration in which an actual opening is formed, or may be a light transmissive glass plate, or transmits light from the fundus of the fundus illumination optical system 10 through the illumination light. The structure which has a wavelength selection characteristic may be sufficient.

  The illumination optical system 10 may be provided, for example, for illuminating the fundus oculi Ef to be examined with illumination light via the mirror portion 22b of the perforated mirror and the objective lens 25. The illumination light may be at least one of visible light and infrared light. The illumination optical system 10 may include a visible illumination optical system for illuminating the fundus oculi Ef with visible light and an infrared illumination optical system for illuminating the fundus oculi Ef with infrared light. The illumination optical system 10 includes an imaging light source 14 and an observation light source 11 and may be provided to illuminate the fundus oculi Ef with at least any illumination light of the imaging light source 14 and the observation light source 11. As the imaging light source 14, for example, a flash lamp that emits visible light or an LED may be used. As the observation light source 11, for example, a halogen lamp that emits infrared light. Infrared LEDs may be used.

  The photographing optical system 30 may be provided for photographing a front image of the fundus oculi Ef illuminated by the illumination light of the illumination optical system 10 through the opening 22a of the perforated mirror 22. The photographing optical system 30 is a visible photographing optical system for photographing a front image of the fundus oculi illuminated by visible light, and an infrared photographing for photographing a front image of the fundus oculi illuminated by infrared light. And an optical system. The imaging optical system 30 may include a two-dimensional imaging element 35 (imaging imaging element) that is disposed at a position conjugate with the fundus and receives reflected light from the fundus. The photographing optical system 30 may include a focusing lens 32 and a two-dimensional image sensor 35. The focusing lens 32 is moved in the optical axis direction in order to adjust the focus on the eye to be examined. The imaging optical system 30 may include a two-dimensional imaging device 38 (observation imaging device) that is disposed at a position conjugate with the fundus and receives reflected light from the fundus. Note that the imaging element for photographing and the imaging element for observation may be formed by the same imaging element.

  The imaging optical system 30 includes a first image sensor (for example, a two-dimensional image sensor 35) for photographing the fundus as a still image and a second image sensor (for example, a two-dimensional image sensor) for observing the fundus with a moving image. And an imaging device 38). Here, an image sensor different from the first image sensor is used for the second image sensor.

  The interference optical system (OCT optical system) 200 may be provided to obtain a tomographic image of the fundus of the eye to be examined through the objective lens 25 using a technique of optical interference.

  More specifically, the interference optical system 200 mainly includes a light source 102, a detector 120, and a scanning unit 108. The detector 120 detects an interference state between the measurement light irradiated on the eye E and the reference light. The measurement light is emitted from the light source 102 and guided to the fundus oculi Ef through the measurement optical path. The reference light is emitted from the light source 102 and guided to the detector 120 through the reference light path.

  The scanning unit 108 is arranged in the measurement optical path and scans the measurement light on the eye E. The scanning unit 108 may repeatedly scan the measurement light on the eye E.

  The apparatus 1 can obtain a tomographic image of the eye E based on detection signals from the detector 120 at each scanning position of the scanning unit 108.

<Anterior segment observation optical system>
In the present apparatus 1, an anterior ocular segment observation optical system 60 for observing an anterior ocular segment front image may be provided. The anterior ocular segment observation optical system 60 may be provided for observing the anterior ocular segment observation image of the subject's eye illuminated by the anterior ocular segment illumination light source 58 via the objective lens 25. The anterior ocular segment observation optical system 60 is, for example, arranged at a position conjugate with the relay lens 64 for condensing the reflected light from the anterior ocular segment and the anterior ocular segment, and receives the reflected light from the anterior ocular segment. And a two-dimensional image sensor 65. As the anterior segment illumination light source 58, for example, an infrared light source may be used.

<Combination of anterior ocular segment observation optical system and OCT optical system to fundus camera optical system using wavelength separation member>
The first wavelength separation member (for example, the dichroic mirror 24) includes a first optical axis L1 shared by the illumination optical system 10 and the photographing optical system 30, and a first optical axis shared by the interference optical system 200 and the anterior ocular segment observation optical system 60. It is provided to make the two optical axes L2 coaxial. The first wavelength separation member may be disposed between the objective lens 25 and the perforated mirror 22.

  The second wavelength separation member (for example, the dichroic mirror 61) is provided to form the second optical axis L2 with the optical axis L3 of the OCT optical system and the optical axis L4 of the anterior ocular segment observation optical system 60 being coaxial. It is done.

  The wavelength separation member described above may be a flat dichroic mirror or a dichroic prism.

  According to the above configuration, for example, when capturing a frontal image of the fundus (for example, a color fundus image) and when capturing a tomographic image of the fundus, alignment is performed using the front image of the anterior segment. Can do. Therefore, in the combined apparatus of the fundus camera and the OCT, the alignment with respect to the eye to be examined can be performed smoothly.

  In another aspect, an anterior ocular segment observation optical system is provided in a combined apparatus of a fundus camera and an OCT without impairing the functions of each other. Therefore, it is possible to perform suitable imaging in both the fundus camera and the OCT, and it is possible to smoothly align the eye to be examined.

  In addition, it is easy to notice an axis deviation caused by the dichroic mirror 24. For example, when the alignment with respect to the eye using the imaging optical system 30 is completed (for example, the working dot W can be used), when the alignment index on the anterior ocular segment observation image is shifted from the reference position, It is recognized that the interference optical system 200 is also off-axis. Therefore, maintenance can be performed smoothly.

  Below, the 1st example of the wavelength selection characteristic of a wavelength separation member is shown. For example, as the light source 102 (measurement light source) of the interference optical system 200, a light source that emits light having a central wavelength (for example, λ = 840 nm, λ = 870 nm, λ = 880 nm, etc.) between λ = 800 nm and 900 nm is used. May be. As the hand width with respect to the center wavelength, for example, a light source having a wavelength band of ± 30 to 60 nm with respect to the center wavelength may be used. Of course, a broadband light source may be used. In the following embodiment, a light source having an emission wavelength of λ = 840 nm to 920 nm is used as the light source 102.

  Furthermore, as the anterior segment illumination light source 58, a light source that emits light having a central wavelength between λ = 900 nm and 1000 nm (more preferably, λ = 940 nm to 1000 nm) may be used. In this case, the center wavelength of the anterior segment illumination light source 58 may be set in a wavelength band longer than the emission wavelength of the light source 102.

  As an illumination light source used in the illumination optical system 10, an observation light source 11 that emits light having a central wavelength (more preferably, λ = 770 nm to 790 nm) between λ = 750 nm and 800 nm, and a visible light shorter than λ = 750 nm A photographic light source 14 that emits light in the region may be used. The observation light source 11 may have a center wavelength set in a wavelength band shorter than the emission wavelength of the light source 102. In the following embodiment, a light source having an emission wavelength of λ = 750 nm to 800 nm is used as the observation light source 11. The imaging light source 14 may be a light source that emits light including a wavelength region from λ = 400 nm to 700 nm (λ = 400 nm to 750 nm in the following embodiment). The wavelength band of the light emitted from each light source may be limited through a cut filter that cuts a predetermined wavelength.

  The first wavelength separation member (for example, the dichroic mirror 24) has a cut-on wavelength set between λ = 760 and 840 nm, for example, transmits at least the fundus observation light from the observation light source 11, and the light source of the interference optical system 100 It has a wavelength selection characteristic for reflecting the measurement light by 102 and the light by the anterior segment illumination light source 58. In this case, the first wavelength separation member transmits most of the fundus oculi observation light from the observation light source 11 and reflects most of the measurement light from the light source 102 and most of the light from the anterior ocular illumination light source 58. Needless to say. In addition, 90% or more of the whole light can be considered as the most part of the light.

  The second wavelength separation member (for example, the dichroic mirror 61) has a cut-on wavelength (or cut-off wavelength) set between, for example, λ = 900 to 1000 nm (preferably λ = 930 nm to 970), and interference optics. It has a wavelength selection characteristic that splits the measurement light from the light source 102 of the system 200 and the anterior ocular segment observation light from the anterior ocular illumination light source 58. The second wavelength separation member may transmit the measurement light and reflect the anterior ocular segment observation light, or may reflect the measurement light and transmit the anterior ocular segment observation light. In this case, it is needless to say that a configuration in which most of the measurement light from the light source 102 of the interference optical system 200 and most of the anterior segment observation light from the anterior segment illumination light source 58 are divided is included.

  According to the above configuration, the light source 102 (measurement light source) of the interference optical system 200 is a wavelength band between λ = 750 nm and 900 nm (more preferably, λ = 800 nm to 900 nm). Also, in addition to fundus photography and fundus observation, anterior ocular segment observation can be favorably performed.

  The first wavelength separation member may further have a wavelength characteristic that transmits fundus photographing light from the photographing light source 14. Alternatively, the first wavelength separation member may be detached from the optical path of the photographing optical system 30 when photographing the fundus using the photographing light source 14.

  In the optical system described above, an index light source 55 (alignment light source) disposed at a position conjugate with the anterior eye portion (for example, the opening 22a of the perforated mirror 22) may be further provided. The index light source 55 may be disposed inside the optical system of the apparatus housing. The index light source 55 is reflected by the anterior segment of the eye to be examined and then received by the two-dimensional imaging device 35 (observation imaging device). The alignment index (so-called working dot W) received by the two-dimensional image sensor 35 is observed by the examiner and used for fine adjustment of the alignment with respect to the eye to be examined.

  As the index light source 55, for example, a light source that emits light having a longer center wavelength than the observation light source 11 and a shorter center wavelength than the light source 102 of the interference optical system 200 is used. More preferably, a light source that emits light having a center wavelength between λ = 780 nm and 815 nm is used.

  Therefore, the first wavelength separation member may have a wavelength characteristic that transmits light from the index light source 55. For the first wavelength separation member, more preferably, the cut-on wavelength is set between λ = 780 nm and 815 nm.

  In the optical system, a focus index projection optical system (hereinafter referred to as a projection optical system) 40 for projecting a focus index (for example, a split index) onto the fundus may be further provided. The focus index is used to manually or automatically adjust the focus on the eye to be examined. As the projection optical system 40, for example, a light source that emits light having a central wavelength comparable to that of the observation light source 11 is used (for example, the central wavelength is set between λ = 765 nm and 785 nm). Therefore, the first wavelength separation member may have a wavelength characteristic that transmits light based on the focus index.

  In the above optical system, an alignment index projection optical system (hereinafter referred to as projection optical system) 50 may be further provided. The projection optical system 50 projects the alignment index from the outside of the objective lens 25 toward the anterior eye portion to be examined. The alignment index is captured by the anterior ocular segment observation optical system 60 and used for automatic alignment or manual alignment using the anterior ocular segment image. As the projection optical system 50, for example, a light source that emits light having a center wavelength comparable to that of the anterior segment illumination light source 75 is used (for example, the center wavelength is set between λ = 900 nm and 1000 nm). Therefore, the first wavelength separation member may have a wavelength characteristic that transmits the alignment index.

  Note that the index light source 55, the projection optical system 40, and the projection optical system 50 described above may be configured such that at least one of them is disposed in the optical system of the apparatus. All of these may be arranged in the optical system of the apparatus.

  Below, the 2nd example of the wavelength selection characteristic of a wavelength separation member is shown. For example, as the light source 102 (measurement light source) of the interference optical system 200, a light source that emits light having a central wavelength (more preferably, λ = 1050 to 1300 nm) between λ = 1000 nm and 1350 nm may be used. The light source 102 is a wavelength swept light source, and an SS-OCT optical system may be used as the interference optical system 200. As the hand width with respect to the center wavelength, for example, a light source having a wavelength band of ± 30 to 60 nm with respect to the center wavelength may be used. Of course, a broadband light source may be used.

  Furthermore, as the anterior segment illumination light source 58, a light source that emits light having a central wavelength between λ = 900 nm and 1000 nm (more preferably, λ = 940 nm to 1000 nm) may be used. In this case, the central wavelength of the anterior segment illumination light source 58 may be set in a wavelength band shorter than the emission wavelength of the light source 102.

  As an illumination light source, an observation light source 11 that emits light having a central wavelength between λ = 750 nm and 900 nm (more preferably, λ = 800 nm to 900 nm), and photographing that emits light in a visible range shorter than λ = 750 nm. A light source 14 may be used. More specifically, the imaging light source 14 may be a light source that emits light including a visible region from λ = 400 nm to 700 nm (λ = 400 nm to 750 nm in the following embodiment). The wavelength band of the light emitted from each light source may be limited through a cut filter that cuts a predetermined wavelength.

  The dichroic mirror (first) 24 has a cut-on wavelength set between, for example, λ = 760 to 900 nm, transmits at least fundus observation light from the observation light source 11, and measures light from the light source 102 of the interference optical system 100; It has a wavelength selection characteristic for reflecting light from the anterior segment illumination light source 58.

  The dichroic mirror (second) 61 has a cut-on wavelength (or cut-off wavelength) set between λ = 950 nm and 1050 nm, for example, and the measurement light from the light source 102 of the interference optical system 100 and the anterior segment illumination light source 58. And has a wavelength selection characteristic for dividing the anterior ocular segment observation light. The dichroic mirror 61 may transmit the measurement light and reflect the anterior ocular segment observation light, or may reflect the measurement light and transmit the anterior ocular segment observation light.

  According to the above configuration, since the wavelength band of λ = 800 nm to 900 nm can be used as the fundus observation light, the burden on the eye to be examined can be reduced.

<Cut filter>
In the anterior ocular segment observation optical system 60, a cut filter that cuts light in a wavelength band corresponding to the measurement light of the interference optical system 200 may be provided in the optical path downstream of the dichroic mirror 61. Since the measurement light of the interference optical system 200 can be cut by the cut filter, the anterior ocular segment observation can be suitably performed.

  The cut filter is disposed between the dichroic mirror 61 and the two-dimensional image sensor 65, for example. The cut filter may be coated on, for example, the relay lens 64 disposed between the second dichroic mirror and the two-dimensional image sensor. Further, it may be arranged separately from the relay lens 64.

  Note that the photographic optical system 30 may also be provided with a cut filter that cuts light in a wavelength band corresponding to the measurement light of the interference optical system 200.

<Fluorescence shooting function>
In the present apparatus, a configuration for acquiring a fluorescence fundus image by fluorescence from the fundus of the subject's eye may be provided. The exciter filter EX is detachably disposed in the optical path of the illumination optical system 10, and has a wavelength selection characteristic that transmits fluorescence excitation light from the light from the imaging light source 14 and cuts light having a wavelength other than the fluorescence excitation light. The exciter filter EX is provided between the photographing light source 14 and the perforated mirror 22, for example, and is inserted and retracted by driving the insertion / removal mechanism A.

  The barrier filter BA is detachably disposed in the optical path of the imaging optical system 30, and has a wavelength selection characteristic that transmits fluorescence from the fundus excited by the fluorescence excitation light and cuts light having a wavelength other than fluorescence. . The barrier filter BA is provided, for example, between the perforated mirror 22 and the image sensor 35 and is inserted and retracted by the insertion / removal mechanism B. More preferably, it may be provided between the dichroic mirror 37 and the two-dimensional image sensor 35 in order to avoid an influence on fundus observation.

  The exciter filter EX and the barrier filter BA may be set with wavelength selection characteristics for taking a fundus fluorescence image by spontaneous fluorescence from the eye to be examined. That is, the exciter filter EX and the barrier filter BA may be used under the condition that the fluorescent agent is not intravenously injected into the subject, and optically emits a fluorescent component spontaneously emitted by exciting the fundus using a specific wavelength. It may be a filter for extracting automatically.

  As a filter for performing spontaneous fluorescence imaging, for example, a filter that uses green light as excitation light and obtains red light fluorescence from the fundus is used. Therefore, the exciter filter EX may have wavelength selection characteristics that transmit green light (for example, light in a band of λ = 500 to 600 nm) and block other light, and the barrier filter BA may be red light (for example, , Λ = 625 to 760 nm band light) and other light may be blocked. The exciter filter EX has a wavelength selection characteristic that transmits green light (for example, light in a band of λ = 500 to 600 nm) and light in a band of λ = 800 nm or more and blocks other light. Good. This is because, as a result, the emission wavelength of the imaging light source 14 does not include light in a band of λ = 800 nm or more, and light other than excitation light is not irradiated to the eye to be examined.

  Further, the exciter filter EX is not limited to a filter that transmits green light. For example, the exciter filter EX may have a wavelength selection characteristic that transmits blue light and blocks other light. Moreover, you may make it provide the imaging | photography light source which emits excitation light instead of providing an exciter filter.

  Further, the barrier filter BA may have a wavelength selection characteristic that transmits red light (for example, light in a band of λ = 625 to 760 nm) and blocks other light. In addition, as a filter for performing autofluorescence imaging | photography, it is not limited to the said filter. For example, the barrier filter BA may transmit light including light having a shorter wavelength than the red component (for example, yellow light) and block other light. For example, the barrier filter BA may transmit light including light having a longer wavelength than the red component (for example, near-infrared light) and block other light.

  The barrier filter BA includes a first light (first fluorescence) having a wavelength band shorter than λ = 700 nm (for example, λ = 625 to 700 nm), a longer wavelength than λ = 700 nm, and a fundus generated by the observation light source 11. It may have a wavelength selective characteristic that transmits fluorescence from the fundus oculi Ef including second light (second fluorescence) that has a wavelength band shorter than the observation light (for example, λ = 700 to 750 nm). .

<Barrier filter for color photography>
In addition to the fluorescent imaging barrier filter (first barrier filter) BA, a second barrier filter BA may be provided that is inserted into the optical path when the fundus of the eye to be examined is color-captured. The second barrier filter BA is detachably disposed in the optical path of the imaging optical system 30 and, in the fundus reflected light from the imaging light source 14, the light in the visible band necessary for color imaging (for example, the visible band including red blue green) Light having a wavelength selection characteristic that cuts light unnecessary for color photography (for example, light in the infrared band). The second barrier filter BA is set such that the upper limit of the wavelength band to transmit is shorter than that of the barrier filter BA for fluorescence photography. For example, the upper limit of the transmission wavelength of the first barrier filter is set to λ = 750 nm, and the upper limit of the transmission wavelength of the second barrier filter is set to λ = 700 nm.

  According to the above configuration, the first barrier filter is selectively inserted into the optical path during fluorescence imaging, and the second barrier filter is selectively inserted into the optical path during color imaging. As a result, the fluorescent fundus image and the color fundus image are each photographed satisfactorily.

<Wavelength separation member considering fluorescence photography>
The photographic optical system 30 is disposed in the optical path of the photographic optical system 30, and a wavelength separation member (for example, a dichroic mirror 37) for branching the optical path of the photographic optical system 30 into a first photographic optical path and a second photographic optical path. ) May be provided.

  The first imaging optical path is an optical path for guiding reflected light and fluorescence from the fundus oculi by the imaging light source 11 to a first imaging element (for example, the two-dimensional imaging element 35), and the second imaging optical path is an observation path. It may be an optical path for guiding the reflected light from the fundus from the light source 11 to the second image sensor (for example, the two-dimensional image sensor 38).

  The wavelength separation member (for example, the dichroic mirror 37) for branching into the first imaging optical path and the second imaging optical path includes fundus reflection light from the imaging light source 14, and the first light and the second light described above. Wavelength selection characteristics are set so that fluorescence is guided to a first image sensor (for example, two-dimensional image sensor 35) and fundus observation light from the observation light source 11 is guided to a second image sensor (for example, two-dimensional image sensor 38). May be.

  More specifically, the wavelength separation member (for example, the dichroic mirror 37) for branching into the first imaging optical path and the second imaging optical path is the fundus reflection light from the imaging light source 14, and the first light and the first light. Wavelength selection characteristics may be provided that transmit fluorescence including the second light and reflect fundus observation light from the observation light source 11. In this case, the wavelength separation member (for example, the dichroic mirror 37) for branching into the first photographing optical path and the second photographing optical path is a part of the fundus reflected light from the photographing light source 14 and the first light described above. Needless to say, it includes a configuration that transmits most of the fluorescence including the second light and reflects most of the fundus observation light from the observation light source 11. In addition, 90% or more of the whole light can be considered as the most part of the light.

  The wavelength separation member (for example, the dichroic mirror 37) for branching into the first imaging optical path and the second imaging optical path emits fundus reflected light from the imaging light source 14 and fluorescence including the first light and the second light. Wavelength selection characteristics that reflect and transmit fundus observation light from the observation light source 11 may be provided.

  The wavelength separation member (for example, the dichroic mirror 37) for branching into the first photographing optical path and the second photographing optical path is the majority of the fundus reflected light from the photographing light source 14, and the first light and the second light described above. Needless to say, it includes a configuration that reflects most of the fluorescence including light and transmits most of the fundus observation light from the observation light source 11. In addition, 90% or more of the whole light can be considered as the most part of the light.

  In this case, a light source that emits light having a center wavelength between λ = 800 nm and 900 nm is used as the light source 102 of the interference optical system 200, and the first light and the second light described above are used as the imaging light source 14. An imaging light source that emits light in the visible range is used, and an observation light source that emits light having a center wavelength between λ = 750 nm and 800 nm is used as the observation light source 11.

  The wavelength separation member (for example, the dichroic mirror 37) for branching into the first photographing optical path and the second photographing optical path has a cut-on wavelength (or cut-off wavelength) set between λ = 725 to 775 nm, and photographing. Wavelength selection so that fundus reflection light from the light source 14 and fluorescence including the first light and the second light described above are guided to the first image sensor, and fundus observation light from the observation light source 11 is guided to the second image sensor. A characteristic may be set.

  According to such a wavelength selection characteristic, the first light (so-called visible light) shorter than λ = 700 nm and the second light (λ) shorter than λ = 700 nm and shorter in wavelength than the fundus observation light by the observation light source ( It is possible to take a fluorescence image by fundus fluorescence including so-called infrared light. As a result, a good fluorescence image can be acquired even with a combined device with OCT. For example, in autofluorescence imaging, since a lipofuscin reaction occurs even in a wavelength component longer than λ = 700 nm, a clinically useful autofluorescence image can be acquired by incorporating this. Further, the amount of spontaneous fluorescence from the fundus is weak, and in addition to the first light shorter than λ = 700 nm, the second light longer than λ = 700 nm is taken in, thereby reducing the light amount of the fluorescent image. Can be supplemented.

  More preferably, the wavelength separation member (for example, the dichroic mirror 37) for branching into the first imaging optical path and the second imaging optical path transmits at least 90% or more of the light of λ = 700 nm to the first imaging element (for example, The wavelength selection characteristic is set so as to guide to the two-dimensional imaging device 35) and to block at least 70% or more of the light of λ = 750 nm. Accordingly, light having a wavelength longer than λ = 700 nm can be sufficiently extracted, and fundus observation light from the observation light source can be blocked well (see FIG. 8).

  More preferably, the wavelength separation member (for example, the dichroic mirror 37) for branching into the first imaging optical path and the second imaging optical path transmits at least 90% or more of the light of λ = 720 nm to the first imaging element (for example, The wavelength selection characteristic is set so as to guide to the two-dimensional imaging device 35) and to block at least 70% or more of the light of λ = 750 nm. Accordingly, light having a wavelength longer than λ = 700 nm can be sufficiently extracted, and fundus observation light from the observation light source can be blocked well (see FIG. 8).

<Fluorescence mode>
In this apparatus, for example, there is provided a mode setting switch for setting either a color photographing mode for obtaining a color front image of the fundus of the eye to be examined or a fluorescent photographing mode for obtaining a fluorescence front image of the fundus of the eye to be examined. May be. When the fluorescent photographing mode is set, the control unit 70 inserts the exciter filter EX and the barrier filter BA into the optical path and causes the photographing light source 14 to emit light during fundus photographing.

  Visible light from the imaging light source 14 is limited to fluorescence excitation light by the exciter filter EX, and the eye to be examined is illuminated by the fluorescence excitation light. The reflected light itself from the fundus due to the excitation light is blocked by the barrier filter BA. Here, fluorescence from the contrast medium or autofluorescence is emitted from the fundus. Fluorescence from the fundus passes through the barrier filter BA via the objective lens 25 to the dichroic mirror 37. Thereby, a fluorescent fundus image is captured by the fluorescent light flux. The captured fluorescent image is stored in the memory 72 and displayed on the display unit 75.

  In the case of spontaneous fluorescence imaging, for example, fluorescence due to lipofuscin contained in the fundus tissue is emitted from the fundus by fluorescence excitation light whose main component is green. As a result, a spontaneous fluorescent fundus image is captured by the fluorescent light flux.

<Example>
As shown in FIG. 1A, the apparatus main body 1 of the present embodiment mainly includes, for example, a base 4, a photographing unit 3, a face support unit 5, and an operation unit 74. The photographing unit 3 may house an optical system described later. The imaging unit 3 may be provided so as to be movable in a three-dimensional direction (XYZ) with respect to the eye E. The face support unit 5 may be fixed to the base 4 in order to support the subject's face.

  The imaging unit 3 may be moved relative to the eye E in the left-right direction, the up-down direction (Y direction), and the front-rear direction by the XYZ drive unit 6. Note that the photographing unit 3 may be moved in the left-right direction (X direction) and the front-rear (working distance) direction (Z direction) with respect to the left and right eyes by the movement of the movable table 2 with respect to the base 4.

  The joystick 74a is used as an operation member operated by the examiner to move the photographing unit 3 with respect to the eye E. Of course, it is not limited to the joystick 74a, and may be another operation member (for example, a touch panel, a trackball, etc.).

  For example, the operation unit once transmits an operation signal from the examiner to the control unit 70. In this case, the control unit 70 may send an operation signal to the personal computer 90 described later. For example, the personal computer 90 sends a control signal corresponding to the operation signal to the control unit 70. For example, when the control unit receives the control signal, the control unit performs various controls based on the control signal.

  For example, the movable table 2 is moved relative to the eye to be examined by operating the joystick 74a. Further, by rotating the rotary knob 74b, the XYZ driving unit 6 is driven in Y and the photographing unit 3 is moved in the Y direction. In addition, the structure which the imaging | photography part 3 is moved with respect to the eye to be examined by the XYZ drive part 6 when the joystick 74a is operated without providing the moving stand 2 may be sufficient.

  The imaging unit 3 may be provided with, for example, a display unit 75 (for example, the examiner side). The display unit 75 may display, for example, a fundus observation image, a fundus photographing image, and an anterior eye observation image.

  In addition, the apparatus main body 1 of this embodiment is connected to a personal computer (hereinafter, PC) 90. For example, a display unit 95 and operation members (keyboard 96, mouse 97, etc.) may be connected to the PC 90.

  As shown in FIG. 2, the optical system of this embodiment mainly includes an illumination optical system 10, a photographing optical system 30, and an interference optical system 200 (hereinafter also referred to as an OCT optical system) 200. Further, the optical system may include a focus index projection optical system 40, an alignment index projection optical system 50, and an anterior ocular segment observation optical system 60. The illumination optical system 10 and the photographing optical system 30 are used as a fundus camera optical system 100 for obtaining a color fundus image by photographing the fundus with visible light (for example, a non-mydriatic state). The imaging optical system 30 captures a fundus image of the eye to be examined. The OCT optical system 200 obtains a tomographic image of the fundus of the eye to be examined non-invasively using an optical interference technique.

<Fundus camera optical system>
Hereinafter, an example of the optical arrangement of the fundus camera optical system 100 will be shown.

<Illumination optics>
The illumination optical system 10 includes, for example, an observation illumination optical system and a photographing illumination optical system. The photographing illumination optical system mainly includes a photographing light source 14, a condenser lens 15, a ring slit 17, a relay lens 18, a mirror 19, a black spot plate 20, a relay lens 21, a perforated mirror 22, and an objective lens 25. The photographing light source 14 may be a flash lamp, an LED, or the like. The black spot plate 20 has a black spot at the center. The imaging light source 14 is used, for example, for imaging the fundus of the subject's eye with light in the visible range.

The observation illumination optical system mainly includes an observation light source 11, an infrared filter 12, a condenser lens 13, a dichroic mirror 16, and an optical system from the ring slit 17 to the objective lens 25. The observation light source 11 may be a halogen lamp, an LED, or the like. The observation light source 11 is used, for example, for observing the fundus of the eye to be examined with light in the near infrared region. The infrared filter 12 is provided to transmit near infrared light having a wavelength of 750 nm or more and cut light having a wavelength band shorter than 750 nm. The dichroic mirror 16 is disposed between the condenser lens 13 and the ring slit 17. The dichroic mirror 16 has a characteristic of reflecting light from the observation light source 11 and transmitting light from the imaging light source 14. Note that the observation light source 11 and the imaging light source 14 may be arranged in series on the same optical axis.

<Photographing optical system>
In the photographic optical system 30, for example, an objective lens 25, a photographing aperture 31, a focusing lens 32, an imaging lens 33, and an image sensor 35 are mainly disposed. The photographing aperture 31 is located in the vicinity of the aperture of the perforated mirror 22. The focusing lens 32 is movable in the optical axis direction. The image sensor 35 can be used for photographing having sensitivity in the visible range. The photographing aperture 31 is disposed at a position substantially conjugate with the pupil of the eye E with respect to the objective lens 25. The focusing lens 32 is moved in the optical axis direction by a moving mechanism 49 including a motor.

  A dichroic mirror 37 having a characteristic of reflecting part of infrared light and visible light and transmitting most of visible light is disposed between the imaging lens 33 and the image sensor 35. In the reflection direction of the dichroic mirror 37, an imaging device for observation 38 having sensitivity in the infrared region is disposed. Instead of the dichroic mirror 34, a flip-up mirror may be used. For example, the flip-up mirror is inserted into the optical path during fundus observation, and is retracted from the optical path during fundus imaging.

  A dichroic mirror (wavelength selective mirror) 24 that can be inserted and removed as an optical path branching member is provided obliquely between the objective lens 25 and the perforated mirror 22. The dichroic mirror 24 reflects the wavelength light of the OCT measurement light and the wavelength light (for example, center wavelength 940 nm) of the alignment index projection optical system 50 and the anterior segment illumination light source 58. Further, the dichroic mirror 24 has a characteristic of transmitting a wavelength of 800 nm or less including a light source wavelength (for example, a center wavelength of 780 nm) of wavelength light for fundus observation illumination. At the time of shooting, the dichroic mirror 24 is flipped up by the insertion / removal mechanism 66 and retracts out of the optical path. The insertion / removal mechanism 66 can be composed of a solenoid and a cam.

  Further, the optical path correction glass 28 is disposed on the image pickup element 35 side of the dichroic mirror 24 so as to be able to be flipped up by driving the insertion / removal mechanism 66. When the optical path is inserted, the optical path correction glass 28 has a role of correcting the position of the optical axis L1 shifted by the dichroic mirror 24.

  The light beam emitted from the observation light source 11 is converted into an infrared light beam by the infrared filter 12 and reflected by the condenser lens 13 and the dichroic mirror 16 to illuminate the ring slit 17. The light transmitted through the ring slit 17 reaches the perforated mirror 22 through the relay lens 18, the mirror 19, the black spot plate 20, and the relay lens 21. The light reflected by the perforated mirror 22 passes through the correction glass 28 and the dichroic mirror 24, and once converges near the pupil of the eye E to be examined by the objective lens 25, and then diffuses to illuminate the fundus of the eye to be examined.

  Reflected light from the fundus is imaged through the objective lens 25, the dichroic mirror 24, the correction glass 28, the aperture of the perforated mirror 22, the imaging aperture 31, the focusing lens 32, the imaging lens 33, and the dichroic mirror 37. An image is formed on the element 38. The image sensor 38 is disposed at a conjugate position with the fundus. The output of the image sensor 38 is input to the control unit 70, and the control unit 70 displays a fundus observation image (fundus frontal observation image) 82 of the eye to be inspected imaged by the image sensor 38 on the display unit 75 (FIG. 3). reference).

  Further, the light beam emitted from the photographing light source 14 passes through the dichroic mirror 16 via the condenser lens 15. Thereafter, the fundus is illuminated with visible light through the same optical path as the illumination light for fundus observation. Then, the reflected light from the fundus is imaged on the image sensor 35 through the objective lens 25, the opening of the perforated mirror 22, the imaging aperture 31, the focusing lens 32, and the imaging lens 33.

<Focus index projection optical system>
The focus index projection optical system 40 mainly includes an infrared light source 41, a slit index plate 42, two declination prisms 43, a projection lens 47, and a spot mirror 44 obliquely provided in the optical path of the illumination optical system 10. The two declination prisms 43 are attached to the slit target plate 42. The spot mirror 44 is provided obliquely in the optical path of the illumination optical system 10. The spot mirror 44 is fixed to the tip of the lever 45. The spot mirror 44 is normally inclined to the optical axis, but is retracted out of the optical path by rotation of the rotary solenoid 46 at a predetermined timing before photographing.

  The spot mirror 44 is arranged at a position conjugate with the fundus of the eye E. The light source 41, the slit indicator plate 42, the deflection prism 43, the projection lens 47, the spot mirror 44 and the lever 45 are moved in the optical axis direction by the moving mechanism 49 in conjunction with the focusing lens 32. Further, the light flux of the slit index plate 42 of the focus index projection optical system 40 is reflected by the spot mirror 44 via the deflection prism 43 and the projection lens 47, and then the relay lens 21, the perforated mirror 22, the dichroic mirror 24, The light is projected onto the fundus of the eye E through the objective lens 25. When the fundus is not focused, the index images S1 and S2 are projected onto the fundus in a state of being separated according to the shift direction and shift amount. On the other hand, when the focus is achieved, the index images S1 and S2 are projected onto the fundus in a matched state (see FIG. 5). The index images S1 and S2 are taken together with the fundus image by the image sensor 38.

<Alignment index projection optical system>
In the alignment index projection optical system 50 for projecting the alignment index beam, a plurality of infrared light sources are arranged at 45 degree intervals on a concentric circle with the photographing optical axis L1 as the center, as shown in the diagram in the upper left dotted line in FIG. Has been placed. The ophthalmologic photographing apparatus in the present embodiment mainly includes a first target projection optical system (0 degrees and 180) and a second target projection optical system. The first target projection optical system has an infrared light source 51 and a collimating lens 52. The second target projection optical system is arranged at a position different from the first index projection optical system and has six infrared light sources 53. The infrared light sources 51 are arranged symmetrically with respect to a vertical plane passing through the photographing optical axis L1. In this case, the first index projection optical system projects an index at infinity on the cornea of the eye E from the left-right direction. The second index projection optical system is configured to project a finite index on the cornea of the eye E from the vertical direction or the oblique direction. In FIG. 2, for convenience, the first index projection optical system (0 degrees and 180 degrees) and only a part of the second index projection optical system (45 degrees and 135 degrees) are shown. .

<Anterior segment observation optical system>
An anterior ocular segment observation (imaging) optical system 60 for imaging the anterior ocular segment of the eye to be inspected has a dichroic mirror 61, a diaphragm 63, a relay lens 64, a two-dimensional imaging element (light receiving element: hereinafter) on the reflection side of the dichroic mirror 24. (It may be abbreviated as “image sensor 65”). The image sensor 65 has infrared sensitivity. The imaging element 65 also serves as an imaging means for detecting the alignment index, and the anterior segment illuminated by the anterior segment illumination light source 58 that emits infrared light and the alignment index are imaged. The anterior segment illuminated by the anterior segment illumination light source 58 is received by the image sensor 65 from the objective lens 25, the dichroic mirror 24, and the dichroic mirror 61 through the optical system of the relay lens 64. Further, the alignment light beam emitted from the light source of the alignment index projection optical system 50 is projected onto the eye cornea to be examined. The cornea reflection image is received (projected) on the image sensor 65 through the objective lens 25 to the relay lens 64.

  The output of the two-dimensional image sensor 65 is input to the control unit 70, and the anterior segment image captured by the two-dimensional image sensor 65 is displayed on the display unit 75 as shown in FIG. The anterior ocular segment observation optical system 60 also serves as a detection optical system for detecting the alignment state of the apparatus main body with respect to the eye to be examined.

  An infrared light source for forming an optical alignment index (working dot W) on the cornea of the subject's eye around the hole of the perforated mirror 22 (two in this embodiment, but is not limited thereto). ) 55 is arranged. The light source 55 may have a configuration in which infrared light is guided to an optical fiber having an end face disposed in the vicinity of the perforated mirror 22. The corneal reflected light from the light source 55 is imaged on the imaging surface of the imaging element 38 when the working distance between the subject eye E and the imaging unit 3 (apparatus body) is appropriate. As a result, the examiner can finely adjust the alignment using the working dots formed by the light source 55 while the fundus image is displayed on the monitor 8.

<OCT optical system>
Returning to FIG. The OCT optical system 200 has a device configuration of a so-called ophthalmic optical coherence tomography (OCT) and takes a tomographic image of the eye E. The OCT optical system 200 divides light emitted from the measurement light source 102 into measurement light (sample light) and reference light by a coupler (light splitter) 104. The OCT optical system 200 guides the measurement light to the fundus oculi Ef of the eye E, and guides the reference light to the reference optical system 110. The measurement light reaches the scanning unit 108 via the collimator lens 123 and the focus lens 124, and the reflection direction is changed by driving two galvanometer mirrors, for example. Then, the measurement light reflected by the scanning unit 108 is reflected by the dichroic mirror 24 and then condensed on the fundus of the eye to be examined through the objective lens 25. Thereafter, interference light obtained by combining the measurement light reflected by the fundus oculi Ef and the reference light is received by the detector (light receiving element) 120.

  The detector 120 detects an interference state between the measurement light and the reference light. In the case of Fourier domain OCT, the spectral intensity of the interference light is detected by the detector 120, and a depth profile (A scan signal) in a predetermined range is obtained by Fourier transform on the spectral intensity data. Examples include Spectral-domain OCT (SD-OCT) and Swept-source OCT (SS-OCT). In the case of Spectral-domain OCT (SD-OCT), for example, a broadband light source is used as the light source 102, and a spectrometer (spectrometer) is used as the detector 120. In the case of Swept-source OCT, for example, a variable wavelength light source is used as the light source 102, and a single photodiode is used as the detector 120 (balance detection may be performed). Moreover, Time-domain OCT (TD-OCT) may be used.

  The scanning unit 108 scans light emitted from the measurement light source on the fundus of the eye to be examined. For example, the scanning unit 108 scans the measurement light two-dimensionally (XY direction (transverse direction)) on the fundus. The scanning unit 108 is disposed at a position substantially conjugate with the pupil. The scanning unit 108 is, for example, two galvanometer mirrors, and the reflection angle thereof is arbitrarily adjusted by the driving unit 151.

  Thereby, the reflection (advance) direction of the light beam emitted from the light source 102 is changed, and is scanned in an arbitrary direction on the fundus. Thereby, the imaging position on the fundus oculi Ef is changed. The scanning unit 108 may be configured to deflect light. For example, in addition to a reflective mirror (galvano mirror, polygon mirror, resonant scanner), an acousto-optic device (AOM) that changes the traveling (deflection) direction of light is used.

  The reference optical system 110 generates reference light that is combined with reflected light acquired by reflection of measurement light at the fundus oculi Ef. The reference optical system 110 may be a Michelson type or a Mach-Zehnder type.

  The reference optical system 110 may change the optical path length difference between the measurement light and the reference light by moving the optical member in the reference light path. For example, the reference mirror 131 is moved in the optical axis direction. The configuration for changing the optical path length difference may be arranged in the measurement optical path of the measurement optical system.

  More specifically, the reference optical system 110 mainly includes, for example, a collimator lens 129, a reference mirror 131, and a reference mirror driving unit 150. The reference mirror driving unit 150 is disposed in the reference optical path and is configured to be movable in the optical axis direction so as to change the optical path length of the reference light. The light is reflected by the reference mirror 131 and returned to the coupler 104 again and guided to the detector 120. As another example, the reference optical system 110 is formed by a transmission optical system (for example, an optical fiber), and guides the light from the coupler 104 to the detector 120 by transmitting the light without returning.

<Control unit>
Next, the control system of this embodiment will be described with reference to FIG. As shown in FIG. 6, the control unit 70 of the present embodiment includes an imaging element 65 for anterior ocular segment observation, an imaging element 38 for infrared fundus observation, a display unit 75, an operation unit 74, a USB 2. A 0 standard HUB 71 is connected to each light source (not shown), various actuators (not shown), and the like. The USB 2.0 HUB 71 is connected with an image sensor 35 built in the apparatus main body 1 and a PC (personal computer) 90.

  The PC 90 includes a CPU 91 as a processor, an operation input unit (for example, a mouse and a keyboard), a memory (nonvolatile memory) 72 as a storage unit, and a display unit 95. The CPU 91 may control the apparatus main body 1. The memory 72 is a non-transitory storage medium that can retain stored contents even when power supply is interrupted. For example, a hard disk drive, flash ROM, USB memory detachably attached to the PC 90, an external server, or the like can be used as the memory 72. The memory 72 stores an imaging control program for controlling imaging of front images and tomographic images by the apparatus main body (ophthalmic imaging apparatus) 1.

  Further, the memory 72 stores an ophthalmic analysis program for using the PC 90 as an ophthalmic analysis apparatus. That is, the PC 90 may also be used as an ophthalmologic analyzer. Further, the memory 72 stores various types of information related to imaging such as tomographic images (OCT data), three-dimensional tomographic images (three-dimensional OCT data), frontal fundus images, and information on imaging positions of tomographic images in the scanning line. Various operation instructions by the examiner are input to the operation input unit.

  A detector (for example, a line CCD or the like) 120 for OCT imaging built in the apparatus main body 1 is connected to the PC 90 via a USB 3.0 port 79a, 79b via a USB signal line. Thus, in this embodiment, the apparatus main body 1 and the PC 90 are connected to each other by the two USB signal lines 76 and 77.

  In addition, the control unit 70 may detect the alignment index from the anterior segment observation image 81 imaged by the image sensor 65. The control unit 70 may detect the amount of alignment deviation of the apparatus main body 1 with respect to the eye to be examined based on the imaging signal of the imaging element 65.

  Further, as shown in the anterior ocular segment image observation screen of FIG. 4 (which may be displayed on the fundus oculi observation screen of FIG. 5), the control unit 70 displays a reticle LT serving as an alignment reference on the screen of the display unit 75. The position may be formed electronically and displayed. Further, the control unit 70 may control the display of the alignment index A1 so that the relative distance from the reticle LT is changed based on the detected amount of alignment deviation.

  The control unit 70 displays the anterior ocular segment observation image captured by the image sensor 65 and the anterior ocular segment observation image and infrared fundus observation image captured by the image sensor 38 on the display unit 75 of the main body.

  Further, the control unit 70 outputs the anterior ocular segment observation image and the fundus oculi observation image to the PC 90 via the HUB 71 and USB 2.0 ports 78a and 78b. The PC 90 displays the anterior ocular segment observation image and the fundus oculi observation image 82 that are output in a streaming manner on the display unit 95 of the PC 90. The anterior ocular segment observation image and the fundus oculi observation image may be simultaneously displayed as live images (for example, a live front image) on the display unit 95 (the anterior ocular segment observation image 81 and the fundus oculi observation image 82 in FIG. 3).

  On the other hand, the photographing of the color fundus image by the image sensor 35 is performed based on a trigger signal from the control unit 70. The color fundus image is also output to the control unit 70 and the PC 90 via the HUB 71 and the USB 2.0 ports 78a and 78b, and displayed on the display unit 75 or the display unit 95 of the PC 90.

  Further, the detector 120 is connected to the PC 90 via the USB 3.0 ports 79a and 79b. The light reception signal from the detector 120 is input to the PC 90. The PC 90 (more specifically, the processor (for example, CPU) of the PC 90) generates the tomographic image 83 by performing arithmetic processing on the light reception signal from the detector 120.

  For example, in the case of Fourier domain OCT (eg, spectral domain OCT), the PC 90 processes a spectral signal including interference signals at each wavelength output from the detector 120. The PC 90 processes the spectrum signal to obtain internal information of the eye to be examined (for example, data of the eye to be examined (depth information) regarding the depth direction). More specifically, the spectrum signal (spectrum data) is rewritten as a function of the wavelength λ, and converted into a function I (k) that is equally spaced with respect to the wave number k (= 2π / λ). The PC 90 obtains a signal distribution in the depth (Z) region by Fourier-transforming the spectrum signal in the wave number k space.

  Furthermore, the PC 90 may obtain information (for example, a tomographic image) of the eye to be examined by arranging internal information obtained at different positions by scanning the measurement light or the like. The PC 90 stores the obtained result in the memory 72. The PC 90 may display the obtained result on the display unit 95.

  The apparatus main body 1 captures an image with a preset scan pattern based on a release signal from the PC 90. The PC 90 processes each image signal and outputs an image result on the display unit 95 of the PC 90.

  At this time, the detector 120 outputs the detected detection signal to the PC 90. The PC 90 generates a tomographic image from the output from the detector 120.

  The PC 90 transfers the generated tomographic image to the apparatus main body 1 via the USB 2.0 ports 78 b and 78 a and the HUB 71. The control unit 70 displays the transferred tomographic image 83 on the display unit 75 (see, for example, the tomographic image 83). The OCT front image may be generated by the PC 90 based on the output signal from the detector 120 and the OCT front image may be displayed on the display unit 75 or the display unit 95.

  In this embodiment, the examiner can perform each setting or alignment of OCT imaging settings, alignment, optimization, and the like while looking at the display unit 75 disposed in the apparatus main body 1 (details will be described later). ). Accordingly, as shown in FIG. 1B, the examiner can save the trouble of alternately checking the display unit 75 of the apparatus main body unit 1 and the display unit 95 on the PC 90 side that are arranged at different positions. Further, when taking an image by opening the subject's eyelid, the examiner may perform the opening operation more easily while checking the display unit 75 than checking the display unit 95 of the PC 90. .

  Furthermore, the tomographic image 83, fundus image 82, anterior ocular segment observation image 81, and the like are displayed on both the display unit 75 and the display unit 95 of the PC 90, so that the examiner operates using the apparatus main body unit 1. It is possible to select whether to operate using the PC 90 according to preference. In addition, since various captured images are displayed on both the display unit 75 and the display unit 95 of the PC 90, the number of screens on which the image can be observed is increased, and it becomes easy for a plurality of people to check the image.

  In the case where measurement is performed separately for an examiner who observes an image with the display unit 95 of the PC 90 and an examiner who performs imaging with the apparatus main body unit 1, the examiner who performs imaging takes the tomography imaged with the display unit 75. If the image 83 is confirmed and shooting is not successful, shooting can be performed again. For this reason, the examiner observing the display unit 95 is less likely to tell the examiner who performs imaging to restart measurement.

  As described above, by displaying the tomographic image 83 on both the display section 75 of the apparatus main body 1 and the display section 95 of the PC 90, the apparatus main body 1 can be adapted to an imaging method that suits the examiner's preference. .

  The same applies to the above-described color fundus photography. The result of color fundus photography is not only input to the PC 90, but also image information such as the preview result is transferred to the apparatus main body via the USB 2.0 ports 78b and 78a and the HUB 71, and displayed on the apparatus main body 1 A color fundus image may be displayed on the portion 75. Thus, the examiner can save the trouble of alternately checking the apparatus main body 1 and the PC 90 in order to see the color fundus image. Further, when operating the apparatus main body 1 while viewing a color fundus photographed image, it is not necessary to look into the display unit 95 on the computer side, and it is only necessary to check the display unit 75, thereby reducing the burden on the examiner.

<Control action>
An example of the control operation in the apparatus having the above configuration will be described. For example, the control unit 70 may combine the captured image from the image sensor 65, the captured image from the image sensor 38, and the OCT image from the PC 90 and display them on the screen of the display unit 75 as an observation screen. As shown in FIG. 3, a live anterior ocular segment observation image 81, a live fundus observation image 82, and a live tomographic image (hereinafter also referred to as a live tomographic image) may be simultaneously displayed on the observation screen.

  The tomographic image 83 is output from the PC 90 to the control unit 70 via the USB 2.0 ports 78 b and 78 a and displayed on the display unit 75. In the present embodiment, the fundus image 82 is displayed at the center of the display unit 75, the anterior ocular segment observation image 81 is displayed at the upper right part, and the tomographic image 83 is displayed at the lower right part. The examiner operates the apparatus main body 1 while confirming these images on the display unit 75.

  The examiner causes the face support unit 5 to support the face of the subject. Then, the examiner instructs the subject to watch the fixation target (not shown). At the initial stage, the dichroic mirror 24 is inserted in the optical path of the photographing optical system 30, and an anterior segment image captured by the image sensor 65 is displayed on the display unit 75.

  For example, the examiner operates the joystick 74a as the vertical / left / right alignment adjustment, and moves the photographing unit 3 left / right / up / down so that the anterior segment image appears on the display unit 75. When the anterior segment image appears on the display unit 75, eight index images (first alignment index images) Ma to Mh appear as shown in FIG. In this case, the imaging range by the imaging element 65 is preferably a range that includes the pupil, iris, and eyelid of the anterior eye portion when the alignment is completed.

<Alignment detection and automatic alignment in XYZ directions>
When the alignment index images Ma to Mh are detected by the two-dimensional image sensor 65, the control unit 70 starts automatic alignment control. The control unit 70 detects the alignment deviation amount Δd of the imaging unit 3 with respect to the eye to be examined based on the imaging signal output from the two-dimensional imaging element 65. More specifically, the XY coordinates of the center of the ring shape formed by the index images Ma to Mh projected in a ring shape are detected as the approximate corneal center, and the alignment reference in the XY directions set in advance on the image sensor 65 is used. A deviation amount Δd between the position O1 (for example, the intersection of the imaging surface of the imaging element 65 and the imaging optical axis L1) and the corneal center coordinates is obtained (see FIG. 7). Note that the center of the pupil may be detected by image processing, and the misalignment may be detected based on the amount of deviation between the coordinate position and the reference position O1.

  Then, the control unit 70 operates automatic alignment by drive control of the XYZ drive unit 6 so that the deviation amount Δd falls within the allowable range A for completion of alignment. Depending on whether the deviation amount Δd is within the allowable range A for completion of alignment and the time continues for a certain time (for example, 10 frames for image processing or 0.3 seconds) (whether the alignment condition A is satisfied). , Whether the alignment in the XY directions is appropriate or not is determined.

  Further, the control unit 70 obtains the alignment deviation amount in the Z direction by comparing the interval between the index images Ma and Me at infinity detected as described above and the interval between the index images Mh and Mf at finite distance. . In this case, when the photographing unit 3 is shifted in the working distance direction, the control unit 70 changes the image interval between the index images Mh and Mf while the interval between the infinite indexes Ma and Me hardly changes. The amount of alignment deviation in the working distance direction with respect to the eye to be examined is obtained using the characteristic of performing (see Japanese Patent Laid-Open No. 6-46999 for details).

  Further, the control unit 70 also obtains a deviation amount with respect to the alignment reference position in the Z direction in the Z direction, and the XYZ driving unit 6 so that the deviation amount falls within an alignment allowable range in which the alignment is completed. The automatic alignment by the drive control is activated. Whether or not the alignment in the Z direction is appropriate is determined based on whether or not the amount of deviation in the Z direction is within an allowable range for completion of alignment for a certain period of time (whether the alignment condition is satisfied).

  When the alignment operation in the XYZ directions satisfies the alignment completion condition by the alignment operation described above, the control unit 70 determines that the alignment in the XYZ directions is matched, and proceeds to the next step.

  Here, when the alignment deviation amount Δd in the XYZ directions falls within the allowable range A1, the drive of the drive unit 6 is stopped and an alignment completion signal is output. Even after the alignment is completed, the control unit 70 detects the displacement amount Δd as needed, and resumes automatic alignment when the displacement amount Δd exceeds the allowable range A1. That is, the control unit 70 performs control (tracking) for tracking the imaging unit 3 with respect to the subject's eye so that the deviation amount Δd satisfies the allowable range A1.

<Determination of pupil diameter>
After the alignment is completed, the control unit 70 starts determining whether or not the pupil state of the eye to be examined is appropriate. In this case, the suitability of the pupil diameter is determined based on whether or not the pupil edge detected from the anterior segment image by the image sensor 65 is out of the predetermined pupil determination area. The size of the pupil determination area is set as a diameter (for example, a diameter of 4 mm) through which the fundus illumination light beam can pass with the image center (imaging optical axis center) as a reference. For simplicity, four pupil edges detected in the horizontal direction and the vertical direction with respect to the center of the image are used. If the pupil edge point is outside the pupil determination area, the illumination light quantity at the time of photographing is sufficiently secured (for details, refer to Japanese Patent Application Laid-Open No. 2005-160549 by the present applicant). The pupil diameter suitability determination is continued until imaging is executed, and the determination result is displayed on the display unit 75.

<Focus state detection / Auto focus>
When the alignment using the image sensor 65 is completed, the control unit 70 performs autofocus on the fundus of the eye to be examined. FIG. 5 is an example of a fundus image captured by the image sensor 38, and focus index images S1 and S2 by the focus target projection optical system 40 are projected at the center of the fundus image. Here, the focus index images S1 and S2 are separated when they are not in focus, and are projected in agreement when they are in focus. The control unit 70 detects the index images S1 and S2 by image processing and obtains separation information thereof. Then, the control unit 70 controls the driving of the moving mechanism 49 based on the separation information of the index images S1 and S2, and moves the lens 32 so that the fundus is in focus.

<Optimization control>
When the alignment completion signal is output, the control unit 70 issues a trigger signal for starting the optimization control, and starts the optimization control operation. The control unit 70 performs optimization so that the fundus site desired by the examiner can be observed with high sensitivity and high resolution. In the present embodiment, the optimization control is control of optical path length adjustment, focus adjustment, and polarization state adjustment (polarizer adjustment). In the optimization control, it is only necessary to satisfy a certain permissible condition for the fundus, and it is not always necessary to adjust to the most appropriate state.

  In the optimization control, the control unit 70 sets the positions of the reference mirror 131 and the focusing lens 124 to the initial positions as initialization control. After the initialization is completed, the control unit 70 moves the reference mirror 131 in one direction from the set initial position in a predetermined step to perform the first optical path length adjustment (first automatic optical path length adjustment). In parallel with the first optical path length adjustment, the control unit 70 focuses information on the fundus of the eye to be examined (for example, movement of the lens 32) based on the focus result of the fundus camera optical system with respect to the fundus of the eye to be examined. Amount). When the in-focus position information is acquired, the control unit 70 moves the focussing lens 124 to the in-focus position and performs autofocus adjustment (focus adjustment). Note that the in-focus position may be a position where the contrast of the tomographic image acceptable as the observation image can be acquired, and is not necessarily the optimum position in the focus state.

  Then, after the focus adjustment is completed, the control unit 70 moves the reference mirror 131 again in the optical axis direction, and performs the second optical path length adjustment for readjustment of the optical path length (fine adjustment of the optical path length). After completing the second optical path length adjustment, the control unit 70 drives the polarizer 133 for adjusting the polarization state of the reference light to adjust the polarization state of the measurement light (for details, refer to Japanese Patent Application No. 2012-56292).

  As described above, when the optimization control is completed, the fundus site desired by the examiner can be observed with high sensitivity and high resolution. Then, the control unit 70 controls driving of the scanning unit 108 and scans the measurement light on the fundus.

  The detection signal (spectral data) detected by the detector 120 is transmitted to the PC 90 via the USB 3.0 ports 79a and 79b (see FIG. 6). The PC 90 receives the detection signal, and generates a tomographic image 83 by processing the detection signal.

  When the PC 90 generates the tomographic image 83, the tomographic image 83 is transmitted to the control unit 70 of the apparatus main body 1 via the USB 2.0 ports 78 b and 78 a and the HUB 71. The control unit 70 receives the tomographic image 83 from the PC 90 via the USB 2.0 ports 78 b and 78 a and the HUB 71 and displays the tomographic image 83 on the display unit 75. As shown in FIG. 3, the control unit 70 displays the anterior ocular segment observation image 81, the fundus oculi observation image 82, and the tomographic image 83 on the display unit 75.

  The examiner confirms the tomographic image 83 updated in real time, and adjusts the alignment in the Z direction. For example, the alignment may be adjusted so that the tomographic image 83 fits within the display frame.

  Of course, the PC 90 may display the generated tomographic image 83 on the display unit 90. The PC 90 may display the generated tomographic image 83 on the display unit 95 in real time. Further, the PC 90 may display the anterior ocular segment observation image 81 and the fundus oculi observation image 82 on the display unit 95 in real time in addition to the tomographic image 83.

  In the case where the focus adjustment of the image is manually performed, the examiner has described that the adjustment is performed by operating the adjustment knob 74d or the like, but the present invention is not limited thereto. For example, the examiner may adjust the image by performing a touch operation on a display unit (for example, the display unit 75) having a touch panel function.

  When the alignment and the image quality adjustment are completed, the control unit 70 controls driving of the scanning unit 108, scans the measurement light on the fundus in a predetermined direction, and outputs a predetermined value from an output signal output from the detector 120 during the scanning. A light reception signal corresponding to the scanning region is acquired to form a tomographic image.

  FIG. 3 is a diagram illustrating an example of a display screen displayed on the display unit 75. The control unit 70 displays on the display unit 75 the anterior ocular segment observation image 81, the fundus oculi observation image 82, the tomographic image 83, and the line 85 acquired by the anterior ocular segment observation optical system 60. A line 85 is an index representing the measurement position (acquisition position) of the tomographic image on the fundus observation image 82. The line 85 is electrically displayed on the fundus observation image 82 on the display unit 75.

  In this embodiment, the imaging condition can be set when the examiner performs a touch operation or a drag operation on the display unit 75. The examiner can specify an arbitrary position on the display unit 75 by a touch operation.

<Scanline settings>
FIG. 3 is a diagram for explaining setting of the scanning position. When the tomographic image and the fundus oculi observation image 82 are displayed on the display unit 75, the examiner sets the position of the tomographic image that the examiner wants to photograph from the fundus oculi observation image 82 on the display unit 75 observed in real time. Here, the examiner moves the line 85 with respect to the fundus oculi observation image 82 by performing a drag operation using the touch panel display 75, and sets the scanning position. If the line is set to be in the X direction, a tomographic image on the XZ plane is taken, and if the line 85 is set to be in the Y direction, a tomographic image on the YZ plane is taken. It has become. Further, the line 85 may be set to an arbitrary shape (for example, an oblique direction or a circle).

  In the present embodiment, the operation of the touch panel type display unit 75 provided in the apparatus main body 1 has been mainly described, but the present invention is not limited to this. The same operation as that of the display unit 75 may be performed by operating a joystick 74a or various operation buttons provided in the operation unit 74 of the apparatus body 1. Also in this case, for example, the operation signal from the operation unit 74 may be transmitted to the PC via the control unit 70, and the PC may transmit a control signal corresponding to the operation signal to the control unit 70.

  When the examiner moves the line 85 relative to the fundus oculi observation image 82, the control unit 70 sets a scanning position at any time, and acquires a tomographic image at the corresponding scanning position. The acquired tomographic image is displayed on the display screen of the display unit 75 as needed. Further, the control unit 70 changes the scanning position of the measurement light based on the operation signal output from the display unit 75 and displays the line 85 at the display position corresponding to the changed scanning position. Since the relationship between the display position of the line 85 (coordinate position on the display unit) and the scanning position of the measurement light by the scanning unit 108 is determined in advance, the control unit 70 corresponds to the set display position of the line 85. The two galvanometer mirrors of the scanning unit 108 are appropriately driven and controlled so that the measurement light is scanned with respect to the scanning range.

<Acquisition of tomographic images>
When the imaging start switch 74c is operated at a desired position by the examiner after adjustment of the imaging conditions is completed, the control unit 70 acquires a tomographic image by B-scan based on the set scanning position. Do. Based on the display position of the line 85 set on the fundus observation image 82, the control unit 70 drives the scanning unit 108 so that the tomographic image of the fundus corresponding to the position of the line 85 is obtained, and emits measurement light. Let it scan.

  The PC 90 generates a tomographic still image based on the detection signal from the detector 120, and transfers the generated still image to the apparatus main body 1. The control unit 70 displays the tomographic still image transferred from the PC 90 on the display unit 75.

  For example, the control unit 70 may cause the display unit 75 to display an OK button and an NG button not shown. The examiner presses the OK button when saving the tomographic image 83 displayed on the display unit 75 in the memory 72, and presses the NG button when not saving. The control unit 70 stores the tomographic image 83 in the memory 72 when the OK button is pressed. On the other hand, the control unit 70 may redo the tomographic image 83 when the NG button is pressed.

  In this way, by displaying the tomographic image 83 on the display unit 75, the examiner can determine whether or not photographing has been performed appropriately without handling the PC 90.

  When the tomographic image is obtained, the control unit 70 proceeds to the step of acquiring the color fundus image 82 by the fundus camera optical system 100. While examining the fundus observation image 82 displayed on the display unit 75, the examiner performs fine adjustment of alignment and focus so that the photographer can take a picture in a desired state. When the examiner inputs the photographing start switch 74c, photographing is performed. The controller 70 drives the insertion / removal mechanism 66 based on the trigger signal from the imaging start switch 74c, thereby causing the dichroic mirror 24 to leave the optical path and causing the imaging light source 14 to emit light.

  When the imaging light source 14 emits light, the fundus of the eye to be examined is irradiated with visible light. Reflected light from the fundus passes through the objective lens 25, the aperture of the perforated mirror 22, the photographing aperture 31, the focusing lens 32, the imaging lens 33, and the dichroic mirror 37 and forms an image on the two-dimensional light receiving element 35. The color fundus image captured by the two-dimensional light receiving element 35 is received by the PC 90 via the HUB 71 and the USB 2.0 ports 78a and 78b, and then stored in the memory 72.

  The PC 90 performs an analysis process on at least one of the tomographic image and the fundus image obtained as described above, and displays the analysis result on the display unit 95. The PC 90 may display the analysis result on the display unit 75.

DESCRIPTION OF SYMBOLS 1 Apparatus main body part 10 Fundus illumination optical system 22 Hall mirror 24 Dichroic mirror 25 Objective lens 30 Fundus imaging optical system 58 Anterior eye part illumination light source 60 Anterior eye part observation optical system 61 Dichroic mirror 70 Control part 75 Display part 90 Computer 95 Display part 102 Measurement light source 200 Interference optical system (OCT optical system)
EX Exciter Filter BA Barrier Filter

Claims (6)

A fundus illumination optical system for illuminating the subject's fundus with illumination light of at least any one of the photographing light source and the observation light source,
A fundus photographing optical system for photographing a front image of the fundus oculi illuminated by the illumination light, comprising a first image sensor for photographing the fundus and a second image sensor for observing the fundus The system,
An OCT optical system for obtaining a tomographic image of the fundus of the eye to be examined using a technique of optical interference;
A barrier filter that is detachably disposed in the optical path of the fundus imaging optical system, transmits fluorescence from the fundus excited by the fluorescence excitation light, and cuts light of a wavelength other than the fluorescence;
A first imaging optical path that is disposed in the optical path of the fundus imaging optical system and guides reflected light and fluorescence from the fundus to be examined by the imaging light source to the first image sensor, and from the fundus to be examined by the observation light source A wavelength separation member for branching the second imaging optical path for guiding the light of the second to the second imaging device;
With
The barrier filter includes a first light shorter than λ = 700 nm and a second light longer than λ = 700 nm and shorter in wavelength than the fundus observation light by the observation light source. A barrier filter that transmits fluorescence;
The wavelength separation member guides the fundus reflection light from the imaging light source and fluorescence including the first light and the second light to the first image sensor, and converts the fundus observation light from the observation light source to the second light source. A fundus photographing apparatus characterized in that a wavelength selection characteristic is set so as to lead to the imaging element. A light source that emits light having a central wavelength between λ = 800 nm and 900 nm is used as a measurement light source of the OCT optical system,
An imaging light source that emits light including the first light and the second light is used as the imaging light source, and light having a center wavelength between λ = 750 nm and 800 nm is emitted as the observation light source. The fundus imaging apparatus according to claim 1, wherein an observation light source is used.   The fundus imaging apparatus according to claim 1, wherein the barrier filter has a wavelength selection characteristic set for capturing a fundus fluorescence image by spontaneous fluorescence.   A second barrier filter that is detachably disposed in an optical path of the fundus photographing optical system, transmits visible band light necessary for color photographing, and cuts infrared band light unnecessary for color photographing; The fundus imaging apparatus according to claim 1, further comprising a second barrier filter having a shorter upper limit of a wavelength band that transmits the fluorescence than the barrier filter that transmits the fluorescence. The wavelength separation member is
The wavelength selection characteristic is set so that at least 90% or more of light having λ = 700 nm is guided to the first image sensor and at least 70% or more of light having λ = 750 nm is blocked. The fundus imaging apparatus according to any one of Items 1 to 4. The wavelength separation member is
The wavelength selection characteristic is set so that at least 90% or more of light having λ = 720 nm is guided to the first image sensor and at least 70% or more of light having λ = 750 nm is blocked. Item 5. Fundus imaging device.