Ophthalmic device and tomogram generation device

Abstract

A device acquires tomographic images of a posterior ocular portion and an anterior ocular portion of an eye to be examined. The ophthalmologic device includes a scanning section, an objective lens, and an optical element. The scanning section scans light emitted from a light source. The objective lens has, in order from the scanning section side, a first lens group and a second lens group, and is an objective lens in which the second lens group is a lens group having positive refractive power. The optical element is capable of being inserted into or removed from an optical path between the second lens group of the objective lens and the scanning section. In a case where the optical element is not inserted into the optical path, the objective lens constitutes a first observation optical system, and light scanned by the scanning section is focused on a first region of the eye to be examined. In a case where the optical element is inserted into the optical path, the objective lens and the optical element constitute a second observation optical system, and light scanned by the scanning section is focused on a second region of the eye to be examined that is different from the first region.

Description

TECHNICAL FIELD

[0001] The present application relates to an ophthalmic apparatus and a tomographic image generating apparatus. BACKGROUND

[0002] In a configuration of a known optical coherence tomography apparatus for acquiring a tomographic image of a fundus or the like of a posterior eye portion of an eye to be examined, a lens attachment is disposed between an objective lens and the eye to be examined, and a tomographic image of an anterior eye portion such as a cornea is acquired (Patent Literature 1). By using the lens attachment in such an optical coherence tomography apparatus, it is possible to acquire tomographic images of both the posterior eye portion and the anterior eye portion of the eye to be examined with one apparatus.

[0003] In the above-described conventional optical coherence tomography apparatus, the lens attachment is disposed between the eye to be examined and the objective lens, and thus it is necessary to readjust the alignment between the detection object and the imaging apparatus each time the observation is switched from the posterior eye portion to the anterior eye portion.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: U.S. Patent Application Publication No. 2008 / 106696 SUMMARY

[0007] The ophthalmic apparatus of the first aspect of the disclosed technology includes: a scanning member for scanning light emitted from a light source; an objective lens including, in order from the scanning member side, a first lens group and a second lens group, the second lens group being a lens group having positive refractive power; and an optical element that is capable of being inserted into or removed from an optical path between the second lens group of the objective lens and the scanning member, in a case where the optical element is not inserted into the optical path, the objective lens constituting a first observation optical system, light scanned by the scanning member being focused on a first region of an eye to be examined, in a case where the optical element is inserted into the optical path, the objective lens and the optical element constituting a second observation optical system, light scanned by the scanning member being focused on a second region of the eye to be examined that is different from the first region.

[0008] An optical tomographic image generation apparatus according to a second aspect of the present technology includes: a light source that generates light for optical coherence tomography (OCT); a splitting section that splits the light from the light source into measurement light and reference light; a scanning section that scans the measurement light; an objective lens that includes, in order from the scanning section side, a first lens group and a second lens group, the second lens group being a lens group having positive refractive power; an optical element that is capable of being inserted into or removed from an optical path between the second lens group of the objective lens and the scanning section; an interference light detector that detects interference light obtained by a combination of return light from an eye under examination and the reference light; and an image generation section that generates a tomographic image of the eye under examination based on the interference light detected by the detector, the objective lens constituting a first observation optical system in a case where the optical element is not inserted into the optical path, light scanned by the scanning section being focused on a first region of the eye under examination, the objective lens and the optical element constituting a second observation optical system in a case where the optical element is inserted into the optical path, light scanned by the scanning section being focused on a second region of the eye under examination. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 is a schematic configuration diagram of an ophthalmic apparatus of the first embodiment.

[0010] Figure 2 is a schematic configuration diagram of a photographing optical system of the first embodiment.

[0011] Figure 3 is a schematic configuration diagram of a part of a photographing optical system between a scanning section and an eye under examination in a case where an optical module for anterior eye portion observation is not inserted into an optical path between a positive first lens group and a positive second lens group.

[0012] Figure 4 is a schematic configuration diagram of a part of a photographing optical system between a scanning section and an eye under examination in a case where an optical module for anterior eye portion observation is inserted into an optical path between a positive first lens group and a positive second lens group.

[0013] Figure 5 is an optical configuration diagram using a thin system to represent a basic structure of a photographing optical system of the first embodiment, and represents a configuration diagram in a case where a negative lens is not inserted into an optical path between two lens groups having positive power (upper portion) and a configuration diagram in a case where the negative lens is inserted into the optical path (lower portion).

[0014] Figure 6 is an optical configuration diagram using a thin system to represent a basic structure of a photographing optical system of a modified example of the first embodiment.

[0015] Figure 7is an optical configuration diagram using a thin system to represent a basic structure of the photographing optical system of the second embodiment.

[0016] Figure 8 is an optical configuration diagram using a thin system to represent a case where light is more focused on the anterior ocular segment of the examined eye in the photographing optical system of the second embodiment.

[0017] Figure 9 is an optical configuration diagram using a thin system to represent a basic structure of the photographing optical system of a further modification example of the second embodiment.

[0018] Figure 10 is an optical configuration diagram using a thin system to represent a basic structure of the photographing optical system of the third embodiment, and shows an optical configuration diagram using a thin system to represent a state where the anterior ocular segment observation is possible with the negative first lens group and the positive second lens group (upper drawing), and an optical configuration diagram using a thin system to represent a state where the posterior ocular segment observation is possible with the switching lens which is a lens having positive refractive power inserted into the optical path between the negative first lens group and the positive second lens group (lower drawing). DETAILED DESCRIPTION

[0019] Hereinafter, an embodiment of the present application will be described in detail with reference to the drawings.

[0020] First Embodiment

[0021] Hereinafter, an ophthalmic apparatus 110 of a first embodiment of the present application will be described with reference to the drawings. Figure 1 Fig. 1 shows a schematic structure of the ophthalmic apparatus 110.

[0022] For convenience of explanation, a Scanning Laser Ophthalmoscope will be referred to as SLO, and Optical Coherence Tomography will be referred to as OCT.

[0023] In a case where the ophthalmic apparatus 110 is disposed on a horizontal plane where a horizontal direction is set as an X direction, a direction perpendicular to the horizontal plane is set as a Y direction, and an optical axis direction of the photographing optical system 116A is set as a Z direction. The apparatus is disposed with respect to an examined eye in such a manner that a pupil center of the examined eye is located on the optical axis in the Z direction. Therefore, the X direction, the Y direction, and the Z direction are directions perpendicular to each other.

[0024] The ophthalmologic apparatus 110 includes an imaging device 14 and a control device 16. The imaging device 14 includes an SLO unit 18 for acquiring an image of the fundus 12A of the eye to be inspected, and an OCT unit 20 for acquiring a tomographic image of the eye to be inspected. Hereinafter, a fundus image generated based on the SLO data acquired by the SLO unit 18 will be referred to as an SLO image. Furthermore, a tomographic image generated based on the OCT data acquired by the OCT unit 20 will be referred to as an OCT image. Furthermore, an SLO image is sometimes referred to as a two-dimensional fundus image. Furthermore, depending on the imaging site on the eye to be inspected 12, an OCT image is sometimes referred to as a fundus tomographic image or an anterior ocular segment tomographic image.

[0025] The ophthalmologic apparatus 110 is an example of the “optical tomographic image generating apparatus” of the disclosed technology.

[0026] The control device 16 includes a computer having a CPU (Central Processing Unit) 16A, a RAM (Random Access Memory) 16B, a ROM (Read-Only Memory) 16C, and an input / output (I / O) interface 16D.

[0027] The control device 16 includes an input / display device 16E connected to the CPU 16A via an I / O interface 16D. The input / display device 16E has a graphical user interface that displays an image of the eye 12 and receives various instructions from the user. A touch panel display can be used for the input / display device 16E.

[0028] The control device 16 also includes an image processing device 17 connected to the I / O interface 16D. The image processing device 17 generates an image of the eye to be inspected 12 based on data obtained by the imaging device 14 .

[0029] The image processing device 17 is an example of a “generating unit” in the disclosed technology.

[0030] As mentioned above and Figure 1 As shown, the control device 16 of the ophthalmic apparatus 110 includes an input / display device 16E, but the disclosed technology is not limited to this. For example, the control device 16 of the ophthalmic apparatus 110 may be configured not to include the input / display device 16E, but to include a separate input / display device physically separate from the ophthalmic apparatus 110. In this case, the display device includes an image processing processor unit that operates under the control of the CPU 16A of the control device 16. This image processing processor unit can display an SLO image, etc., based on an image signal output as an instruction by the CPU 16A.

[0031] The imaging device 14 operates under the control of the control device 16. The imaging device 14 includes an SLO unit 18, an imaging optical system 116A, and an OCT unit 20. The imaging optical system 116A moves in the X, Y, and Z directions via an imaging optical system driver 116M under the control of the CPU 16A. Alignment (positioning) between the imaging device 14 and the subject's eye 12 can be achieved, for example, not only by moving the imaging device 14 in the X, Y, and Z directions, but also by moving the entire ophthalmologic apparatus 110 in the X, Y, and Z directions.

[0032] The SLO system is composed of Figure 1 The control device 16, SLO unit 18 and photographic optical system 116A shown are implemented.

[0033] The SLO unit 18 includes a plurality of light sources. Figure 1 As shown, the SLO unit 18 includes a light source 40 for B light (blue light), a light source 42 for G light (green light), a light source 44 for R light (red light), and a light source 46 for IR light (infrared light (e.g., near-infrared light)). The light emitted from each light source 40, 42, 44, 46 is directed to the same optical path via optical components 48, 50, 52, 54, 56. Optical components 48 and 56 are composed of reflectors, and optical components 50, 52, 54 are composed of spectrometers. B light is guided to the optical path of the photographic optical system 116A via the optical components 48, 50, 54. G light is guided to the optical path of the photographic optical system 116A via the optical components 50 and 54. R light is guided to the optical path of the photographic optical system 116A via the optical components 52 and 54. IR light is guided to the optical path of the photographic optical system 116A via the optical components 56 and 52. Furthermore, LED light sources and laser light sources can be used as light sources 40, 42, 44, and 46. The following description uses an example of a laser light source. Total reflection mirrors can be used as optical components 48 and 56. Furthermore, dichroic mirrors, half-transparent mirrors, and the like can be used as optical components 50, 52, and 54.

[0034] Light sources 40 , 42 , 44 , and 46 are examples of “laser light sources” in the disclosed technology.

[0035] The SLO unit 18 is configured to be switchable between various light emission modes, such as a light emission mode for emitting G light, R light, B light, and IR light individually, a light emission mode for emitting all of these lights simultaneously, or a light emission mode for emitting several of these lights simultaneously. Figure 1 In the example shown, four light sources are provided: a B (blue) light source 40, a G light source 42, an R light source 44, and an IR light source 46. However, the disclosed technology is not limited to this. For example, the SLO unit 18 may also include a white light source. In this case, in addition to the various light emission modes described above, a light emission mode that emits only white light may also be set.

[0036] The laser light incident to the photographing optical system 116A from the SLO unit 18 is scanned in the X direction and the Y direction by the scanning section (120, 142) described later. The scanning light passes through the pupil 27 and is irradiated to the posterior ocular portion (for example, the fundus 12A) of the eye 12 under examination. The reflected light reflected by the fundus 12A is incident to the SLO unit 18 via the photographing optical system 116A.

[0037] The scanning section (120, 142) is an example of the "scanning means" of the present technology.

[0038] The reflected light reflected by the fundus 12A is detected by the light detecting elements 70, 72, 74, 76 provided to the SLO unit 18. In the present embodiment, the SLO unit 18 is provided with the B light detecting element 70, the G light detecting element 72, the R light detecting element 74, and the IR light detecting element 76 corresponding to the plurality of light sources, that is, the B light source 40, the G light source 42, the R light source 44, and the IR light source 46. The B light detecting element 70 detects the B light reflected at the beam splitter 64. The G light detecting element 72 detects the G light transmitted from the beam splitter 64 and reflected at the beam splitter 58. The R light detecting element 74 detects the R light transmitted from the beam splitters 64, 58 and reflected at the beam splitter 60. The IR light detecting element 76 detects the G light transmitted from the beam splitters 64, 58, 60 and reflected at the beam splitter 62. As the light detecting elements 70, 72, 74, 76, for example, an APD (avalanche photodiode) can be cited.

[0039] The light detecting elements 70, 72, 74, 76 are examples of the "laser light detector" of the present technology.

[0040] Under the control of CPU 16A, image processing device 17 generates SLO images corresponding to respective colors using the signals detected by B light detection element 70, G light detection element 72, R light detection element 74, and IR light detection element 76. The SLO images corresponding to respective colors include a B-SLO image generated using the signal detected by B light detection element 70, a G-SLO image generated using the signal detected by G light detection element 72, an R-SLO image generated using the signal detected by R light detection element 74, and an IR-SLO image generated using the signal detected by IR light detection element 76. Furthermore, in the case of an emission pattern in which B light source 40, G light source 42, and R light source 44 emit light simultaneously, an RGB-SLO image can be synthesized from the B-SLO image, G-SLO image, and R-SLO image generated using the signals detected by R light detection element 74, G light detection element 72, and B light detection element 70. Furthermore, in the case of a light emission mode in which the G light source 42 and the R light source 44 emit light simultaneously, an RG-SLO image can be synthesized from the R-SLO image and the G-SLO image generated using the signals detected by the R light detection element 74 and the G light detection element 72. In the first embodiment, the RG-SLO image is used as the SLO image, but the present invention is not limited to this, and other SLO images can also be used.

[0041] As the beam splitters 58 , 60 , 62 , and 64 , dichroic mirrors, half mirrors, and the like can be used.

[0042] The OCT system is composed of Figure 1 The control device 16, OCT unit 20 and imaging optical system 116A shown in the figure implement a three-dimensional image acquisition device. The OCT unit 20 includes a light source 20A, a sensor (detection element) 20B, a first optical coupler 20C, a reference optical system 20D, a collimating lens 20E and a second optical coupler 20F.

[0043] The first optical coupler 20C is an example of a “dividing unit” in the present disclosure. The sensor (detection element) 20B is an example of an “interference light detector” in the present disclosure.

[0044] The light source 20A generates light for optical coherence tomography. As the light source 20A, for example, a super luminescent diode (SLD) or the like can be used. The light source 20A emits light of low coherence from a wideband light source having a wide spectral width. The light emitted from the light source 20A is split at the first optical coupler 20C. One of the beams split after the split is made parallel light by the collimator lens 20E to be used as measurement light after the parallel light is made to serve as measurement light by the photographing optical system 116A. The measurement light is scanned in the X direction and the Y direction by the scanning sections (148, 142) described later. The scanned light is irradiated to the posterior ocular portion via the anterior ocular portion and the pupil 27 of the eye to be examined. The measurement light reflected at the anterior ocular portion or the posterior ocular portion passes through the photographing optical system 116A and is incident on the OCT unit 20. Then, the measurement light passes through the collimator lens 20E and the first optical coupler 20C before being incident on the second optical coupler 20F. Further, in the present embodiment, SD-OCT using an SLD as the light source 20A is exemplified, but is not limited thereto, and SS-OCT using a wavelength-swept light source instead of the SLD can also be employed.

[0045] The other of the beams emitted from the light source 20A and split by the first optical coupler 20C is incident on the reference optical system 20D as reference light, and is incident on the second optical coupler 20F via the reference optical system 20D.

[0046] The measurement light (return light) reflected and scattered by the eye to be examined 12 passes through the second optical coupler 20F to be combined with the reference light, and generates interference light. The interference light is detected by the sensor 20B. The image processing device 17 generates a tomographic image of the eye to be examined 12 on the basis of the detection signal (OCT data) from the sensor 20B.

[0047] In the first embodiment, the OCT system generates a tomographic image of the anterior ocular portion or the posterior ocular portion of the eye to be examined 12.

[0048] The anterior ocular portion of the eye to be examined 12 is a portion of the anterior segment of the eye, and includes, for example, the cornea, the iris, the limbus, the lens, the ciliary body, and a portion of the vitreous body. The posterior ocular portion of the eye to be examined 12 is a portion of the posterior segment of the eye, and includes, for example, the remaining portion of the vitreous body, the retina, the choroid, and the sclera. Further, the portion of the vitreous body belonging to the anterior ocular portion is the corneal side portion of the vitreous body inside the vitreous body, which is bounded by the X-Y plane passing through the point of the lens closest to the center of the eyeball, and the portion of the vitreous body belonging to the posterior ocular portion is the portion of the vitreous body inside the vitreous body other than the portion belonging to the anterior ocular portion.

[0049] In a case where the anterior ocular portion of the eye to be examined 12 is the site to be imaged, the OCT system generates a tomographic image of, for example, the cornea. In addition, in a case where the posterior ocular portion of the eye to be examined 12 is the site to be imaged, the OCT system generates a tomographic image of, for example, the retina.

[0050] The posterior eye portion and the anterior eye portion are examples of the "first region" and the "second region" of the present technology, respectively.

[0051] Figure 2 An outline configuration of the photographing optical system 116A is shown in FIG. 2. The photographing optical system 116A includes, in order from the side of the eye 12 to be examined, an objective lens 130, a beam splitter 178, a horizontal scanning section 142, a relay lens device 140, a beam splitter 147, a vertical scanning section 120, 148, a focus adjustment device 150, and a collimator lens 156.

[0052] As the beam splitters 178, 147, for example, a dichroic mirror, a half mirror, or the like can be used.

[0053] The horizontal scanning section 142 is an optical scanner for horizontal direction scanning of the SLO scanning laser light or the OCT measurement light that is incident via the relay lens device 140. In the present embodiment, the horizontal scanning section 142 is shared by the SLO optical system and the OCT optical system, but is not limited thereto. The horizontal scanning sections can be provided separately in the SLO optical system and the OCT optical system.

[0054] The collimator lens 156 makes the light that is emitted from the OCT unit 20, advances in the optical fiber, and is emitted from the end portion 158 of the optical fiber into measurement light, and makes it into parallel light.

[0055] The focus adjustment device 150 includes a plurality of lenses 152, 154. By moving the plurality of lenses 152, 154 in the optical axis direction, respectively, in accordance with the photographing site in the eye 12 to be examined, the focus position of the measurement light in the eye 12 to be examined is adjusted. Further, although not shown, in the case where a focus detection device is provided, the lenses 152, 154 can be driven by the focus adjustment device in accordance with the state of focus detection, so as to realize an autofocus device that automatically performs focusing.

[0056] The vertical scanning section 148 is an optical scanner for vertically scanning the measurement light that is incident via the focus adjustment device 150.

[0057] The vertical scanning section 120 is an optical scanner for vertically scanning the laser light that is incident from the SLO unit 18.

[0058] The relay lens device 140 includes a plurality of lenses 144, 146 having positive refractive power. The relay lens device 140 is configured by the plurality of lenses 144, 146 so as to position the vertical scanning sections 148, 120 and the horizontal scanning section 142. More specifically, the relay lens device 140 is configured in such a manner that the center positions of the scanning angles of the two scanning sections are conjugate.

[0059] A beam splitter 147 is disposed between the relay lens device 140 and the vertical scanning section 148. The beam splitter 147 is an optical member that combines the SLO optical system and the OCT optical system. The beam splitter 147 reflects the SLO light emitted from the SLO unit 18 toward the relay lens device 140 and transmits the measurement light emitted from the OCT unit 20 toward the relay lens device 140. The measurement light emitted from the OCT unit 20 is two-dimensionally scanned by the vertical scanning section 148 and the horizontal scanning section 142. In addition, the light emitted from the SLO unit 18 is two-dimensionally scanned by the vertical scanning section 120 and the horizontal scanning section 142 that constitute the SLO optical system. The OCT measurement light that is two-dimensionally scanned and the SLO laser light that is two-dimensionally scanned are respectively incident on the eye to be examined 12 via the objective lens 130 that constitutes the common optical system. The SLO laser light reflected by the eye to be examined 12 is incident on the SLO unit 18 via the objective lens 130, the horizontal scanning section 142, the relay lens device 140, the beam splitter 147, and the vertical scanning section 120. In addition, the OCT measurement light that has passed through the eye to be examined 12 is incident on the OCT unit 20 via the objective lens 130, the horizontal scanning section 142, the relay lens device 140, the beam splitter 147, the vertical scanning section 148, the focal point adjustment device 150, and the collimator lens 156.

[0060] Examples of parts suitable for use as the horizontal scanning section 142 and the vertical scanning sections 120, 148 include resonant scanners, scanning galvanometer mirrors, polygon mirrors, rotating mirrors, Dove prisms, double Dove prisms, rotating prisms, MEMS scanning mirrors, acousto-optic elements (AOMs), and the like. In the present embodiment, a scanning galvanometer mirror is used as the vertical scanning section 148, and a polygon mirror is used as the vertical scanning section 120. Furthermore, in a case where a two-dimensional optical scanner such as a MEMS scanning mirror is used instead of the optical scanners such as the polygon mirror and the scanning galvanometer mirror, since the incident light can be two-dimensionally angle-scanned by the reflecting element therein, the relay lens device 140 can also be omitted.

[0061] The objective lens 130 has, in order from the horizontal scanning section 142 side, a first lens group 134 and a second lens group 132. At least the second lens group 132 is a positive lens group that has positive refractive power as a whole. In the first embodiment, the first lens group 134 is also a positive lens group that has positive refractive power as a whole. The first lens group 134 and the second lens group 132 each include at least one positive lens. In a case where the first lens group 134 and the second lens group 132 each include a plurality of lenses, as long as the first lens group 134 and the second lens group 132 each have positive refractive power as a whole, these lens groups can each include a negative lens.

[0062] The first lens group 134 and the second lens group 132 constituting the objective lens 130 are separated by the maximum air gap on the optical axis between the lens surfaces of the objective lens. Furthermore, a glass plate having no refractive power may be located between the first lens group 134 and the second lens group 132. This glass plate is not considered a lens belonging to either the first lens group 134 or the second lens group 132; the first lens group 134 and the second lens group 132 are separated by the maximum air gap.

[0063] The photographic optical system 116A includes an anterior segment observation optical module 136, which is an optical module that can be inserted into and removed from the optical path of the objective lens 130, and a sensor 130S, which detects the insertion / removal state of the optical module 136. As will be described in detail later, in the first embodiment, when the optical module 136 is not arranged in the optical path of the objective lens 130, the posterior segment observation optical system 300 is configured as the observation optical system (see also FIG. Figure 3 ), the ophthalmologic apparatus 110 thereby acquires an image of the posterior segment of the subject's eye 12. On the other hand, when the optical module 136 is inserted into the optical path of the objective lens 130, the anterior segment observation optical system 400 is constituted as the observation optical system (also refer to Figure 4 ), the ophthalmic device 110 thereby acquires an image of the anterior segment of the eye to be inspected 12. As will be described in detail later, in the first embodiment, the optical module 136 is manually or automatically inserted into or removed from the optical path of the observation optical system by an operator (e.g., an ophthalmologist). The optical module 136 is inserted into or removed from the optical path between the first lens group 134 and the second lens group 132 by moving along a track not shown in the figure or by rotating a turntable not shown in the figure. The sensor 130S for detecting the insertion / removal state of the optical module 136 for anterior segment observation may be a sensor that detects either the case where the optical module 136 has been inserted into the photographic optical system or the case where the optical module 136 has been removed from the photographic optical system, or may be a sensor that can detect both cases.

[0064] The posterior segment observation optical system 300 is an example of the “first observation optical system” and the “fundus observation optical system” of the present disclosure. The anterior segment observation optical system 400 is an example of the “second observation optical system” and the “anterior segment observation optical system” of the present disclosure.

[0065] Hereinafter, in this embodiment, the state in which the subject's eye 12 is observed without the anterior segment observation optical module 136 being arranged in the optical path of the imaging optical system is referred to as the posterior segment observation mode (first mode). Furthermore, the state in which the subject's eye 12 is observed with the optical module 136 arranged in the optical path of the imaging optical system is referred to as the anterior segment observation mode (second mode).

[0066] like Figure 2 As shown, the imaging optical system 116A further includes an optical module 138, which is separate from the anterior segment observation optical module 136. The optical module 138 is primarily used in the posterior segment observation mode and is therefore hereinafter referred to as the posterior segment observation optical module 138. Although not shown, the posterior segment observation optical module 138 includes an optical module housing 138H that includes a fixation light, a camera, and an illumination device, as well as a beam splitter 178. The beam splitter 178 is disposed between the objective lens 130 and the horizontal scanning unit 142, more specifically, in the optical path between the first lens group 134 and the horizontal scanning unit 142.

[0067] Next, refer to Figure 3 and Figure 4 The configuration of the imaging optical system 116A in each of the posterior segment observation mode and the anterior segment observation mode will be described. Figure 3 FIG. 3 shows the posterior segment observation optical system 300 in the posterior segment observation mode. The anterior segment observation optical module 136 is removed from the optical path of the objective lens 130 . Figure 4 4 shows the anterior segment observation optical system 400 in the anterior segment observation mode. The anterior segment observation optical module 136 is inserted into the optical path of the objective lens 130, specifically, into the optical path between the first lens group 134 on the horizontal scanning unit 142 side and the second lens group 132 on the subject's eye side. Figure 3 ) shows the following light conditions: parallel light beams at three angles provided from the scanning surface representing the horizontal scanning unit 142 pass through two positive lens groups (the first lens group 134 and the second lens group 132) and are focused on the fundus 12A of the eye to be inspected 12. In addition, in the anterior ocular segment observation optical system 400 ( Figure 4 ) shows the following light conditions: the same parallel light beams at three angles provided from the horizontal scanning unit 142 are focused on the cornea of ​​the eye to be inspected 12 through two positive lens groups (the first lens group 134 and the second lens group 132) and an optical element inserted between the two positive lens groups (the negative lens 162 described in detail later).

[0068] In the posterior ocular observation optical system 300, as shown in FIG. Figure 3 and Figure 2As shown, the vertical scanning section 120, the 148, and the horizontal scanning section 142 are arranged in a manner that is conjugate with the pupil position Pp of the eye 12 to be examined. In the SLO optical system, the SLO laser light scanned by the vertical scanning section 120 and the horizontal scanning section 142 passes through the objective lens 130 and is two-dimensionally angle-scanned in a manner that the pupil position Pp of the eye 12 to be examined is located at the center. As a result, the focal point of the SLO laser light is two-dimensionally scanned on the fundus 12A. Likewise, in the OCT optical system, the measurement light scanned by the vertical scanning section 148 and the horizontal scanning section 142 passes through the objective lens 130 and is two-dimensionally angle-scanned in a manner that the pupil position Pp of the eye 12 to be examined is located at the center. As a result, the focal point of the measurement light is two-dimensionally scanned on the fundus 12A. In the posterior eye observation mode in which the image is acquired using the posterior eye observation optical system 300, the fundus two-dimensional image is acquired by the SLO unit 18, and the fundus tomographic image is acquired by the OCT unit 20. As described later, the fundus two-dimensional image is continuously acquired by the SLO unit 18 sequentially during the period in which the fundus tomographic image is acquired by the OCT unit 20.

[0069] In the anterior eye observation optical system 400, as shown, Figure 4 the optical module 136 for anterior eye observation is inserted into the optical path of the objective lens 130, specifically, between the first lens group 134 having positive refractive power (refractive force) and the second lens group 132 having positive refractive power, which constitute the objective lens 130. The optical module 136 includes an internal optical element such as a lens. The optical element in the present embodiment is a lens 162 having negative refractive power and serving as a switching lens. The lens 162 is arranged on the optical axis of the objective lens 130, and the lens 162 functions as a switching lens for switching the posterior eye observation optical system 300 to the anterior eye observation optical system 400. Hereinafter, the lens 162 is sometimes referred to as a negative lens 162 and sometimes referred to as a switching lens 162. In the case where the negative lens 162 is inserted into the optical path of the objective lens 130, the scanning position of the horizontal scanning section 142 is not conjugate with the pupil position Pp of the eye 12 to be examined, and parallel light from the scanning position of the horizontal scanning section 142 is focused on the anterior eye. The diameter of the light beam passing through the negative lens 162 is smaller than the diameters of the light beams passing through the first lens group 134 and the second lens group 132, respectively. Therefore, the effective diameter of the negative lens 162 is smaller than the effective diameters of the lens groups constituting the objective lens 130. The negative lens 162 is smaller than the first lens group 134 and the second lens group 132, so that the optical module 136 is made more compact. Furthermore, the optical element is not limited to the use of the negative lens 162, and an optical member such as a Fresnel lens, a DOE (Diffractive Optical Element), or the like can be used instead of the negative lens 162. In addition, as shown in Figure 3 and Figure 4As shown, the anterior segment observation optical module 136 includes an eye tracking module 160 and a dichroic mirror 161, which are used when observing the anterior segment. Multiple SLO images sequentially acquired by the SLO unit are used as eye tracking images when performing OCT imaging using the eye tracking module 160 built into the anterior segment observation optical module 136.

[0070] The eye tracking module 160 further includes a fixation lamp, a camera, and an illumination device (not shown).

[0071] Next, the optical configuration in the posterior segment observation mode and the anterior segment observation mode will be described. Figure 5 The upper figure schematically shows the posterior segment observation optical system in the posterior segment observation mode (first mode). The anterior segment observation optical module 136 is not inserted into the optical path of the objective lens 130. Figure 5 The following figure schematically illustrates the anterior segment observation optical system in the anterior segment observation mode (second mode). An optical module 136, which includes a negative switching lens 162, is inserted into the optical path of the objective lens 130. For ease of explanation, only the switching lens 162 is shown as the optical module 136 in the schematic diagram of the anterior segment observation optical system.

[0072] Optical system for observing the back of the eye ( Figure 5 The optical system ( Figure 5 In the upper figure, the multiple lens groups that make up objective lens 130, namely, positive first lens group 134 and positive second lens group 132, form an afocal system, and the scanning center (Ps in the figure) of horizontal scanning section 142 is conjugate with pupil position Pp of the eye to be inspected 12. In this configuration, d = f1 + f2, where f1 and f2 are the focal lengths of first lens group 134 and second lens group 132, respectively, and d is the distance between first lens group 134 and second lens group 132 (inter-group spacing).

[0073] The amplification factor β is defined as:

[0074] β=-f2 / f1.

[0075] In the posterior segment observation mode (first mode) of the first embodiment, the scanning position Ps of the horizontal scanning unit 142 is conjugate with the pupil position Pp of the eye 12 to be examined. Parallel light from the scanning position Ps of the horizontal scanning unit 142 passes through the pupil position Pp of the eye 12 to be examined as substantially parallel light at a predetermined angle, and is focused on the fundus 12A by the eye 12 to be examined. The focus position of the measurement light emitted from the OCT unit 20 on the fundus 12A is determined by the scanning position of the vertical scanning unit 120 and the scanning angle at the scanning position (Ps) of the horizontal scanning unit 142. This allows the desired scanning position and scanning range to be set for imaging and observing the fundus 12A.

[0076] Next, the anterior eye portion observation optical system (100) will be described. In this observation optical system, the switching lens 162 of the anterior eye portion observation optical module 136 is inserted into the optical path of the objective lens 130. Figure 5 The following drawing) will be described. In this observation optical system, the switching lens 162 of the anterior eye portion observation optical module 136 is inserted into the optical path of the objective lens 130.

[0077] In the anterior eye portion observation mode (second mode), the switching lens 162, which is a negative lens, is inserted between the first lens group 134 and the second lens group 132. In the anterior eye portion observation mode (second mode), the scan position Ps of the horizontal scanning section 142 is not conjugate with the pupil position Pp of the subject eye 12, and parallel light from the scan position Ps of the horizontal scanning section 142 is focused on the anterior eye portion. The focus position of the measurement light emitted from the OCT unit 20 at the anterior eye portion is determined depending on the scan angle at the position (Ps) of the scanning section. Thus, the anterior eye portion observation can be performed.

[0078] Here, the configuration of the switching lens 162 in the anterior eye portion observation mode (second mode) will be described. f3 represents the focal length of the switching lens 162, x represents the distance between the first lens group 134 and the switching lens 162, S3 represents the object distance of the switching lens 162 in the case where parallel light from the scan position Ps is incident on the first lens group 134, and S3' represents the image distance of the switching lens 162. Further, the image position P3' in the drawing is the image position based on the scan position Ps of the switching lens 162, that is, the conjugate position based on the scan position Ps of the switching lens, in the case where parallel light from the scan position Ps is incident on the first lens group 134, and the image position P3' is conjugate with the pupil position Pp of the subject eye 12.

[0079] From the imaging formula related to the switching lens 162, the following is obtained:

[0080] [Equation 1]

[0081]

[0082] From S3 = f1 - x, the following is obtained:

[0083] [Equation 2]

[0084]

[0085] Next, as with the second lens group 132, S2 represents the object distance of the second lens group 132 in the case where parallel light from the scan position Ps is incident on the first lens group 134, and S2' represents the image distance, and from the imaging formula related to the second lens group 132, the following is obtained:

[0086] [Equation 3]

[0087]

[0088] Further, S2' is substantially the distance of the second lens group 132 from the eye 12 under examination, i.e. the so-called working distance WD. In addition, from Figure 5 It is known that

[0089] S2 = S3' + d - x.

[0090] Therefore,

[0091] [Equation 4]

[0092]

[0093] Substituting equation (1) into equation (2) gives:

[0094] [Equation 5]

[0095]

[0096] Arranging equation (3) for x gives the following equation.

[0097] [Equation 6]

[0098]

[0099] When the focal length f3 of the switching lens 162 is determined, the value of the position x can be found using this equation (4).

[0100] Further, in the case where the light between the two positive first lens group 134 and second lens group 132 is parallel light, f2 = S2'. Therefore, from equation (3) becomes the following simple relationship equation (5).

[0101] x = f1 + f3 (5)

[0102] By approximation, a structure can be adopted in which the switching lens 162 is disposed between the first lens group 134 and the second lens group 132 according to this relationship equation (5). This relationship equation (5) is applicable in the case where the two positive first lens group 134 and second lens group 132 form a perfect afocal system, and the light between the two groups is perfect parallel light, and thus can be said to be an ideal structure. In practice, it is clear that the shape, thickness and refractive index of each lens, etc. should be appropriately selected by appropriate aberration calculation to set the two lens groups as a substantially parallel system, and to achieve appropriate aberration configuration in both the posterior eye portion observation mode (first mode) and the anterior eye portion observation mode (second mode).

[0103] In the first embodiment, as Figure 5As shown, the distance (working distance WD) between the second lens group 132 and the eye 12 to be inspected does not change, regardless of whether in the posterior segment observation mode (first mode) or the anterior segment observation mode (second mode). Therefore, there is no need to readjust the alignment between the eye 12 to be inspected and the photographic optical system 116A according to the change of each observation mode, and thus there is no need to force the inspection subject to move. Since it is possible to switch between anterior and posterior segment imaging smoothly and quickly, the time required for a series of imaging can be shortened. In addition, since the switching lens 162 is small, the mechanism for inserting and removing the switching lens 162 can also be realized with a simple and compact mechanism.

[0104] In the ophthalmologic apparatus 110 of the first embodiment described above, the anterior segment observation optical module 136 is used, thereby providing an apparatus for acquiring three-dimensional image data of both the posterior segment and the anterior segment of the subject's eye 12 using a single ophthalmologic apparatus.

[0105] Furthermore, the ophthalmologic apparatus 110 of the first embodiment can switch between the posterior segment observation optical system and the anterior segment observation optical system by inserting or removing the anterior segment observation optical module 136 into or from the optical path between the first lens group 134 and the second lens group 132 constituting the objective lens 130. Consequently, the working distance WD between the objective lens 130 (particularly the second lens group 132) and the subject's eye 12 remains unchanged in each optical system (300, 400). Consequently, since there is no need to re-align the subject's eye 12 with the imaging optical system 116A, switching between the posterior segment observation mode and the anterior segment observation mode can be performed smoothly.

[0106] Furthermore, in the ophthalmologic apparatus 110 of the first embodiment, the optical elements of the anterior segment observation optical module 136 are small lenses having an effective diameter smaller than that of the objective lens 130 (the first lens group 134 and the second lens group 132), thereby making the optical module 136 more compact. Consequently, switching between the posterior segment observation optical system and the anterior segment observation optical system is easily possible.

[0107] The above-described features make it possible to improve the convenience of the ophthalmologic apparatus 110 in the first embodiment.

[0108] Next, a modification of the first embodiment will be described.

[0109] The first embodiment includes a negative lens as the switching lens 162 , but the disclosed technology is not limited thereto. The switching lens 162 may also be a lens having positive refractive power (positive lens). Figure 6 FIG. 1 shows a schematic optical structure of an objective lens as a main part of the photographic optical system 116B having a positive lens as a switching lens 162. In this case,Figure 6 The position Pc conjugate to the scan position Ps of the horizontal scanning section 142 is located near the second lens group 132. Figure 6 is the optical structure of the front eye portion photographic optical system in the front eye portion observation mode that becomes the state of photographing the front eye portion, and corresponds to the lower drawing of Figure 5 In this structure, the optical structure of the rear eye portion observation mode (first mode) that becomes the state of photographing the rear eye portion corresponds to the upper drawing (rear eye portion observation optical system 300) of Figure 5 In this structure, the optical structure of the rear eye portion observation mode (first mode) that becomes the state of photographing the rear eye portion corresponds to the upper drawing (rear eye portion observation optical system 300) of Figure 6 In this structure, the optical structure of the rear eye portion observation mode (first mode) that becomes the state of photographing the rear eye portion corresponds to the upper drawing (rear eye portion observation optical system 300) of Figure 5 The lens groups are expressed as thin systems as in

[0110] In the first embodiment, the operator manually removes the front eye portion observation optical module 136 from the optical path of the photographic optical system 116A or manually inserts the optical module 136 into the optical path, but the present technology is not limited to this. For example, a mechanism that automatically removes the front eye portion observation optical module 136 from the optical path or automatically inserts the optical module 136 into the optical path can be provided. The CPU 16A can control the mechanism to automatically remove the front eye portion observation optical module 136 from the optical path or automatically insert the optical module 136 into the optical path in a case where a not-illustrated rear eye portion tomographic image generation button is turned on or in a case where a not-illustrated front eye portion tomographic image generation button is turned on.

[0111] In the first embodiment, the objective lens 130, the horizontal scanning section 142, and the relay lens device 140 are disposed in this order from the subject eye 12 to function as a common optical system shared by the SLO optical system and the OCT optical system, but the present technology is not limited to this. Instead of the structure in which the horizontal scanning section 142 is shared by the SLO optical system and the OCT optical system, a horizontal scanning section and a vertical scanning section can be provided in each optical system.

[0112] Second Embodiment

[0113] Next, the second embodiment will be described. The structure of the second embodiment is substantially the same as that of the first embodiment, and therefore the same parts are labeled with the same reference numerals and the description thereof will be omitted, and mainly the different parts will be described.

[0114] Figure 7 The outline optical structure of the objective lens as a main part in the photographic optical system 116C of the second embodiment is shown in

[0115] The switching lens 162 of the photographing optical system 116C is not configured in a manner that can be inserted into or removed from between the first lens group 134 and the second lens group 132 constituting the objective lens 130, but in a manner that can be inserted into or removed from between the first lens group 134 and the horizontal scanning section 142. As shown in FIG. 16, a structure of the anterior eye portion observation optical system using a lens having positive refractive power as the switching lens 162 in the anterior eye portion observation mode is shown. A position Pc conjugate with the scanning position Ps of the horizontal scanning section 142 is located between the first lens group 134 and the second lens group 132. Figure 7

[0116] The posterior eye portion observation optical system in the posterior eye portion observation mode for fundus photography is similar to that of the upper drawing of FIG. 17. In the structure of FIG. 17, the scanning light of the parallel light beam from the horizontal scanning section 142 can be focused on the vicinity of the anterior eye portion of the subject eye 12 by inserting the switching lens 162. However, in order to be focused completely on the anterior eye portion of the subject eye, as shown in FIG. 18, the focusing device, for example, the focal point adjustment device 150 shown in FIG. 19, converts the light beam incident to the scanning section into light focused appropriately so that the desired position of the anterior eye portion of the subject eye 12 can be focused properly. Figure 5 Figure 7 Figure 8 Figure 2

[0117] Next, a modification of the second embodiment will be described. In the second embodiment, a lens having positive refractive power is used as the switching lens 162, but the present technology is not limited to this. A negative lens can also be used as the switching lens 162. Figure 9 An example of a photographing optical system 116D provided with a lens having negative refractive power as the switching lens 162 is shown. Figure 9 An example of the light rays in the structure of the anterior eye portion observation mode (second mode) in a state where a lens having negative refractive power is used as the switching lens 162 and inserted between the scanning position Ps of the horizontal scanning section 142 and the first lens group 134 of the objective lens 130 to photograph the anterior eye portion is shown. As shown in the drawing, the parallel light beam incident from the center of the horizontal scanning section 142 is focused on the cornea, which is the anterior eye portion of the subject eye 12, by the switching lens 162 having positive refractive power, the first lens group 134 having positive refractive power, and the second lens group 132 having positive refractive power. In this anterior eye portion observation mode (second mode), a virtual image Pv of the position Ps of the horizontal scanning section 142 is formed between the scanning position Ps of the horizontal scanning section 142 and the negative switching lens 162 by the switching lens 162 having negative refractive power. The position Pc conjugate with the scanning position Ps of the horizontal scanning section 142 is formed inside the subject eye 12 by the composite optical system constituted by the lens 162 having negative refractive power, the first lens group 134, and the second lens group 132, but is not limited to this. Of course, by removing the switching lens 162 from between the first lens group 134 and the second lens group 132, the position Pc conjugate with the scanning position Ps of the horizontal scanning section 142 is formed outside the subject eye 12.​​​​​Figure 9 The structure of the anterior segment observation mode (second mode) shown in FIG. 1 is removed, and the same Figure 5 The posterior ocular observation mode (first mode) has the same structure as shown in the upper figure.

[0118] Third embodiment

[0119] Next, the third embodiment will be described. Figure 5 Corresponding parts are denoted by the same reference numerals and their descriptions are omitted, and the description will focus on the different parts.

[0120] First, in the modified examples of the first and second embodiments, the objective lens 130 is composed of two lens groups, each having positive refractive power. However, the disclosed technology is not limited to this. The first lens group 134, which is provided on the side of the horizontal scanning unit 142, that is, on the side of the scanning position Ps, may also be composed of a lens group having negative refractive power.

[0121] like Figure 10 As shown, the photographic optical system 116E of the third embodiment includes a first lens group 134N having negative refractive power instead of the first lens group 134 having positive refractive power in the photographic optical system 116A of the first embodiment. Figure 10 The figure above shows the structure of the anterior segment observation optical system in the anterior segment observation mode for anterior segment photography. Figure 10 The lower figure shows the structure of the posterior ocular observation optical system in the posterior ocular observation mode for posterior ocular photography by inserting a switching lens, and both structures are shown using a thin system.

[0122] First, in Figure 10 In the configuration shown in the figure above, a parallel light beam from the horizontal scanning unit 142 at the scanning position Ps is focused on the pupil position Pp of the eye 12 by the objective lens consisting of two groups: the first lens group 134N having negative refractive power and the second lens group 132 having positive refractive power. This state is obtained after the switching lens 162 is removed from the optical path. Figure 10The structure shown in the lower drawing of FIG. 16 shows the structure of the posterior ocular observation optical system in the posterior ocular observation mode, and shows a state in which the switching lens 162 having positive refractive power is inserted into the optical path between the first lens group 134N having negative refractive power and the second lens group 132 having positive refractive power of the objective lens. In this state, a parallel light beam provided from the scan position Ps of the horizontal scan section 142 becomes a parallel light beam at the pupil position Pp of the examined eye by the combined system of the first lens group 134N having negative refractive power, the switching lens 162 having positive refractive power, and the second lens group 132 having positive refractive power, thereby constituting an afocal system as a whole. The scan position Ps of the horizontal scan section 142 and the pupil position Pp of the examined eye 12 are constituted to be conjugate to each other, the parallel light beam at the pupil position Pp of the examined eye 12 is angularly scanned in accordance with the angular scanning of the beam by the scan section, and the focused light is scanned on the fundus. Further, in the posterior ocular observation mode, the switching lens 162 having positive refractive power is inserted into the optical path between the first lens group 134N having negative refractive power and the second lens group 132 having positive refractive power of the objective lens, and the switching lens 162 having positive refractive power is used as a part of the posterior ocular observation optical system. Therefore, the switching lens 162 having positive refractive power is used as a part of the posterior ocular observation optical system in the posterior ocular observation mode. Figure 10 In the lower drawing of FIG. 16, only the switching lens 162 in the optical module 136 is shown. Here, the position conjugate to the fundus is indicated by a broken line Cr, and the position conjugate to the fundus of the examined eye is formed between the inserted lens 162 having positive refractive power and the second lens group 132 having positive refractive power.

[0123] In the photographic optical system of this third embodiment, the photographing of the anterior ocular portion is possible in the state shown in the upper drawing of FIG. 17 in which the optical module 136 is not inserted, and the photographing of the posterior ocular portion is possible in the state shown in the lower drawing of FIG. 17 in which the optical module 136 is inserted. Therefore, the optical module 136 in this case is an anterior ocular portion switching module. Figure 10 Figure 10 In the photographic optical system of this third embodiment, the photographing of the anterior ocular portion is possible in the state shown in the upper drawing of FIG. 17 in which the optical module 136 is not inserted, and the photographing of the posterior ocular portion is possible in the state shown in the lower drawing of FIG. 17 in which the optical module 136 is inserted. Therefore, the optical module 136 in this case is an anterior ocular portion switching module.

[0124] In the first embodiment, the modification of the first embodiment, the modification of the second embodiment, and the third embodiment described above, the focus adjustment can also be performed as in the second embodiment. Further, in each of the examples, the focus adjustment can also be performed by the auto focus as described above. Further, the focus adjustment can also be performed by moving at least one element of the optical system on the light source side more than the second lens group 132 of the objective lens, such as the first lens group 134 of the objective lens, the switching lens 162, or the lenses 144, 146, and the like. The above embodiments have the significant advantage described above, that is, the tomographic image of the anterior ocular portion can be generated without shifting the position of the examined eye 12 from the position at the time of generating the tomographic image of the posterior ocular portion, and conversely, the position of the examined eye does not need to be changed at all when switching from generating the tomographic image of the anterior ocular portion to generating the tomographic image of the posterior ocular portion.

[0125] Further Modification

[0126] ​In addition to the examples described above, the following structure can also be employed: a plurality of switching lenses or the like optical elements having different powers are prepared, and an optical element of the plurality of optical elements is switched to an optical element that enables light to be focused better on the cornea position in accordance with the shape of the anterior eye portion (e.g., the cornea) that is acquired in advance.

[0127] In addition to the examples described above, the following structure can also be employed: in accordance with the shape of the anterior eye portion (e.g., the cornea), not only is the insertion position of the switching lens or the like optical element switched to a position between the first lens group 134 and the second lens group 132 or a position between the horizontal scanning portion 142 and the first lens group 134, but also an optical element having a different power is selected from a plurality of switching lenses or the like optical elements having different powers and is inserted into the appropriate switching position.

[0128] In addition, in each of the examples described above, the interference light is detected by one detector in both the posterior eye portion observation mode (first mode) and the anterior eye portion observation mode (second mode), but the present technology is not limited thereto. For example, two detectors having different detection capabilities can be provided, one of the two detectors is used to detect the interference light in the posterior eye portion observation mode (first mode), and the other of the two detectors is used to detect the interference light in the anterior eye portion observation mode (second mode).

[0129] Explanation of Reference Signs

[0130] 110: Ophthalmic device

[0131] 17: Image processing device

[0132] 20C: First optical coupler

[0133] 40, 42, 44, 46: Light source

[0134] 70, 72, 74, 76: Light detecting element

[0135] 20B: Sensor

[0136] 132: Second lens group

[0137] 134: First lens group

[0138] 142: Horizontal scanning portion

[0139] 148: Vertical scanning portion

[0140] 162: Switching lens

[0141] 300: Posterior eye portion observation optical system

[0142] 400: Anterior eye portion observation optical system

Claims

1. An ophthalmic apparatus comprising: a scanning section for scanning light emitted from a light source; an objective lens comprising, in order from the scanning section side, a first lens group and a second lens group, the first lens group of the objective lens being a lens group having positive refractive power, the second lens group being a lens group having positive refractive power; and an optical element capable of being inserted into or removed from an optical path between the first lens group of the objective lens and the second lens group of the objective lens, the optical element having negative refractive power, the objective lens constituting a first observation optical system in which light scanned by the scanning section is focused on a first region of an eye to be examined, in a case where the optical element is not inserted into the optical path, the objective lens and the optical element constituting a second observation optical system in which light scanned by the scanning section is focused on a second region of the eye to be examined different from the first region, in a case where the optical element is inserted into the optical path.

2. The ophthalmic apparatus according to claim 1, wherein the first observation optical system constitutes a fundus observation optical system of an afocal system, the first region being a posterior eye portion of the eye to be examined, the second observation optical system constitutes an anterior eye portion observation optical system, the second region being an anterior eye portion of the eye to be examined.

3. The ophthalmic apparatus according to claim 1 or 2, wherein the optical element is capable of being inserted into or removed from between the scanning section and the first lens group.

4. The ophthalmic apparatus according to claim 1 or 2, further comprising a focusing lens that adjusts a focus position of the light emitted from the light source in an optical axis direction.

5. An optical tomographic image generation apparatus comprising: a light source that generates light for optical coherence tomography (OCT); a splitting section that splits the light from the light source into measurement light and reference light; a scanning section for scanning the measurement light; an objective lens comprising, in order from the scanning section side, a first lens group and a second lens group, the first lens group of the objective lens being a lens group having positive refractive power, the second lens group being a lens group having positive refractive power; an optical element capable of being inserted into or removed from an optical path between the first lens group of the objective lens and the second lens group of the objective lens, the optical element having negative refractive power; an interference light detector that detects interference light obtained by a combination of return light from an eye to be examined and the reference light; and an image generation section that generates a tomographic image of the eye to be examined based on the interference light detected by the interference light detector, the objective lens constituting a first observation optical system in which light scanned by the scanning section is focused on a first region of the eye to be examined, in a case where the optical element is not inserted into the optical path, the objective lens and the optical element constituting a second observation optical system in which light scanned by the scanning section is focused on a second region of the eye to be examined, in a case where the optical element is inserted into the optical path.

6. The optical tomographic image generation apparatus according to claim 5, further comprising: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ A laser light source which generates laser light for a scanning laser ophthalmoscope (SLO); and a laser light detector which detects laser light reflected from a fundus of the eye under examination, the laser light being irradiated to the fundus of the eye under examination via the objective lens.

Images