Ophthalmic optical devices

Abstract

This invention provides an ophthalmic optical device that eliminates the need to place a separate lens attachment between the objective lens and the eye under examination by changing the working distance between the objective lens and the eye under examination when observing the posterior segment and when observing the anterior segment. [Solution] In the ophthalmic optical device, when photographing the posterior segment of the eye under examination, a position conjugate to the vertical scanning unit is formed in the anterior segment of the eye under examination, and the scanning beam from the vertical scanning unit is focused on the posterior segment of the eye under examination. When photographing the anterior segment of the eye under examination, the working distance, which is the distance between the eye under examination and the objective lens, is greater than the working distance when photographing the posterior segment, and the scanning beam from the vertical scanning unit is focused on the anterior segment of the eye under examination. The scanning direction of the scanning beam by the vertical scanning unit is the same when photographing the posterior segment and when photographing the anterior segment.

Description

Technical Field

[0001] The present disclosure relates to an ophthalmic optical device.

Background Art

[0002] In the specification of U.S. Patent No. 7,830,525, an optical coherence tomography device for acquiring a tomographic image of the posterior segment of an eye to be examined, such as the fundus of the eye, discloses that a lens attachment is disposed between an objective lens and the eye to be examined to acquire a tomographic image of the anterior segment of the eye, such as the cornea. According to this optical coherence tomography device, by using the lens attachment, tomographic images of each of the posterior segment and the anterior segment of the eye to be examined can be acquired with one device.

[0003] In the above conventional optical coherence tomography device, since the lens attachment is disposed between the eye to be examined and the objective lens, movement of the subject is required for the attachment replacement operation performed in front of the subject's eyes, which is burdensome for the subject and also takes time for the examination.

Summary of the Invention

[0004] An ophthalmic optical device according to a first aspect of the technology of the present disclosure includes a scanning member that scans an eye to be examined with a light beam from a light source, a light guiding optical system that guides the light beam from the light source to the scanning member, and an objective optical system that guides the scanning light beam from the scanning member to the eye to be examined. In a posterior segment imaging state for imaging the posterior segment of the eye to be examined, a conjugate position with the scanning member is formed in the anterior segment of the eye to be examined, and the scanning light beam from the scanning member is focused on the posterior segment of the eye to be examined. In an anterior segment imaging state for imaging the anterior segment of the eye to be examined, an operating distance, which is the distance between the eye to be examined and the objective optical system, becomes larger than the operating distance in the posterior segment imaging state, the scanning light beam from the scanning member is focused on the anterior segment of the eye to be examined, and a scanning direction of the scanning light beam by the scanning member is the same in the posterior segment imaging state and the anterior segment imaging state.

Brief Description of the Drawings

[0005] [Figure 1] It is a schematic configuration diagram of the ophthalmic optical device of this embodiment. [Figure 2A] It is an optical path diagram showing a schematic configuration of the imaging optical system during posterior eye observation in this embodiment. [Figure 2B] It is an optical path diagram showing a schematic configuration of the imaging optical system during anterior eye observation in this embodiment. [Figure 3A] It is a schematic optical path diagram showing the state of the optical system centered on the objective lens during posterior eye observation. [Figure 3B] It is a schematic optical path diagram showing the state of the optical system centered on the objective lens during anterior eye observation. [Figure 3C] It is a schematic optical path diagram showing the state of the optical system centered on the objective lens during observation of the inside of the eyeball. [Figure 4A] It is an explanatory diagram for calculating the ray angle at the scanner position existing at the pupil conjugate position during anterior eye observation. [Figure 4B] It is an explanatory diagram for calculating the ray angle at the scanner position existing at the pupil conjugate position during observation of the inside of the eyeball. [Figure 5A] It is a schematic optical path diagram showing the state of the fixation target projection system and the optical system centered on the objective lens during posterior eye observation. [Figure 5B] It is a schematic optical path diagram showing the state of the fixation target projection system and the optical system centered on the objective lens during anterior eye observation. [Figure 6] It is a flowchart showing an example of processing in the ophthalmic optical device according to this embodiment. [Figure 7A] It is an optical path diagram seen from the side of the configuration of the optical system related to the alignment of the ophthalmic optical device during posterior eye observation. [Figure 7B] It is an optical path diagram seen from above of the configuration of the optical system related to the alignment of the ophthalmic optical device during posterior eye observation. [Figure 8A] It is an optical path diagram seen from the side of the configuration of the optical system related to the alignment of the ophthalmic optical device during anterior eye observation. [Figure 8B] It is an optical path diagram seen from above of the configuration of the optical system related to the alignment of the ophthalmic optical device during anterior eye observation. [Figure 9]This is a lateral view of the optical path diagram showing other components of the optical system related to the alignment of ophthalmic optical devices during posterior segment observation. [Figure 10] This is a lateral view of the optical system configuration related to the alignment of ophthalmic optical devices during anterior segment observation. [Modes for carrying out the invention]

[0006] Hereinafter, an ophthalmic optical device 110 according to an embodiment of this disclosure will be described with reference to the drawings. Figure 1 shows a schematic configuration of the ophthalmic optical device 110.

[0007] For the sake of clarity, we will refer to the Scanning Laser Ophthalmoscope as "SLO" and the Optical Coherence Tomography as "OCT".

[0008] When the ophthalmic optical device 110 is installed on a horizontal plane, the horizontal direction is defined as the "X direction," the direction perpendicular to the horizontal plane is defined as the "Y direction," and the optical axis direction of the imaging optical system 116A is defined as the "Z direction." The device is positioned relative to the eye under examination so that the center of the pupil of the eye under examination is located on the optical axis in the Z direction. The X, Y, and Z directions are perpendicular to each other.

[0009] The ophthalmic optical device 110 includes an imaging device 14 and a control device 16. The imaging device 14 includes an SLO unit 18 that acquires an image of the fundus 12A of the eye under examination 12, and an OCT unit 20 that acquires a tomographic image of the eye under examination 12. Hereinafter, the fundus image generated based on the SLO data acquired by the SLO unit 18 will be referred to as an SLO image. Similarly, the tomographic image generated based on the OCT data acquired by the OCT unit 20 will be referred to as an OCT image. Note that the SLO image may also be referred to as a two-dimensional fundus image. Furthermore, depending on the imaging site of the eye under examination 12, the OCT image may also be referred to as a fundus tomographic image or an anterior segment tomographic image.

[0010] The control unit 16 includes a computer having a CPU (Central Processing Unit) 16A, RAM (Random Access Memory) 16B, ROM (Read-Only memory) 16C, and input / output (I / O) ports 16D.

[0011] The control device 16 includes an input / display device 16E connected to the CPU 16A via an I / O port 16D. The input / display device 16E has a graphic user interface for displaying images of the eye under examination 12 and receiving various instructions from the user. The input / display device 16E can use a touch panel display.

[0012] Furthermore, the control device 16 includes an image processing device 17 connected to the I / O port 16D. The image processing device 17 generates an image of the eye under examination 12 based on the data obtained by the imaging device 14.

[0013] As described above, in Figure 1, the control device 16 of the ophthalmic optical device 110 is equipped with an input / display device 16E, but the technology of this disclosure is not limited thereto. For example, the control device 16 of the ophthalmic optical device 110 may not be equipped with an input / display device 16E, but may be equipped with a separate input / display device that is physically independent of the ophthalmic optical device 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. The image processing processor unit may display an SLO image or the like based on an image signal that the CPU 16A has instructed to output.

[0014] 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 is moved in the X, Y, and Z directions by the imaging optical system drive unit 116M under the control of the CPU 16A. Alignment between the imaging device 14 and the eye under examination 12 may be performed, for example, by moving not only the imaging device 14 but also the entire ophthalmic optical system 110, or some of the optical elements in the imaging optical system 116A, in the X, Y, and Z directions.

[0015] The SLO system is implemented by the control device 16, SLO unit 18, and imaging optical system 116A shown in Figure 1.

[0016] The SLO unit 18 is equipped with multiple light sources. For example, as shown in Figure 1, the SLO unit 18 is equipped with a B-light (blue light) light source 40, a G-light (green light) light source 42, an R-light (red light) light source 44, and an IR-light (infrared light (e.g., near-infrared light)) light source 46. The light emitted from each light source 40, 42, 44, and 46 is directed to the same optical path via each optical element 48, 50, 52, 54, and 56. Optical elements 48 and 56 are mirrors, and optical elements 50, 52, and 54 are beam splitters. The B-light is guided to the optical path of the imaging optical system 116A via optical elements 48, 50, and 54. The G-light is guided to the optical path of the imaging optical system 116A via optical elements 50 and 54. The R-light is guided to the optical path of the imaging optical system 116A via optical elements 52 and 54. The IR light is guided to the optical path of the imaging optical system 116A via optical components 56 and 52. LED light sources or laser light sources can be used as light sources 40, 42, 44, and 46. An example using a laser light source is described below. Total internal reflection mirrors can be used as optical components 48 and 56. Dichroic mirrors, half mirrors, etc., can be used as optical components 50, 52, and 54.

[0017] The SLO unit 18 is configured to allow switching between various emission modes, such as emission modes that individually emit G light, R light, B light, and IR light, and emission modes that emit all of them simultaneously or some of them simultaneously. In the example shown in Figure 1, there are four light sources: a B light (blue light) light source 40, a G light light source 42, an R light light source 44, and an IR light light source 46, but the technology of this disclosure is not limited to this. For example, the SLO unit 18 may further include a white light light source. In this case, in addition to the various emission modes described above, an emission mode that emits only white light may be set.

[0018] The laser light incident from the SLO unit 18 to the imaging optical system 116A is scanned in the X and Y directions by the scanning units (120, 142) described later. The scanning light passes through the pupil 27 and irradiates the posterior segment of the eye under examination 12 (e.g., the fundus 12A). The reflected light reflected by the fundus 12A passes through the imaging optical system 116A and is incident on the SLO unit 18. The scanning units (120, 142, 168), together with the relay lens device 140 described later, are examples of "scanning members" in the technology of this disclosure.

[0019] The reflected light from the fundus 12A is detected by photodetectors 70, 72, 74, and 76 provided in the SLO unit 18. In this embodiment, corresponding to multiple light sources, namely the B light source 40, G light source 42, R light source 44, and IR light source 46, the SLO unit 18 is equipped with a B light detection element 70, a G light detection element 72, an R light detection element 74, and an IR light detection element 76. The B light detection element 70 detects the B light reflected by the beam splitter 64. The G light detection element 72 detects the G light that passes through the beam splitter 64 and is reflected by the beam splitter 58. The R light detection element 74 detects the R light that passes through the beam splitters 64 and 58 and is reflected by the beam splitter 60. The IR light detection element 76 detects the IR light that passes through the beam splitters 64, 58, and 60 and is reflected by the beam splitter 62. Examples of the photodetectors 70, 72, 74, and 76 include APDs (avalanche photodiodes).

[0020] The image processing device 17, under the control of the CPU 16A, generates SLO images corresponding to each color using the signals detected by the 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 each color are the B-SLO image generated using the signal detected by the B light detection element 70, the G-SLO image generated using the signal detected by the G light detection element 72, the R-SLO image generated using the signal detected by the R light detection element 74, and the IR-SLO image generated using the signal detected by the IR light detection element 76. In addition, in the emission mode in which the B light source 40, G light source 42, and R light source 44 emit light simultaneously, an RGB-SLO image may be synthesized from the B-SLO image, G-SLO image, and R-SLO image generated using the signals detected by the R light detection element 74, G light detection element 72, and B light detection element 70, respectively. Furthermore, in the emission mode in which the G light source 42 and R light source 44 emit light simultaneously, an RG-SLO image may be synthesized from the G-SLO image and R-SLO image generated using the respective signals detected by the R light detection element 74 and the G light detection element 72. In this embodiment, an RG-SLO image is used as the SLO image, but it is not limited to this, and other SLO images can be used.

[0021] Dichroic mirrors, half mirrors, etc., can be used as beam splitters 58, 60, 62, and 64.

[0022] The OCT system is a three-dimensional image acquisition device realized by the control device 16, OCT unit 20, and imaging optical system 116A shown in Figure 1. 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 collimator lens 20E, and a second optical coupler 20F.

[0023] The light source 20A generates light for optical coherence tomography. For example, a superluminescent diode (SLD) can be used as the light source 20A. The light source 20A generates low-coherence light from a broadband light source with a wide spectral width. The light emitted from the light source 20A is split by the first optical coupler 20C. One of the split beams is made parallel by the collimator lens 20E and then incident on the imaging optical system 116A as measurement light. The measurement light is scanned in the X and Y directions by the scanning units (148, 168), which will be described later. The scanning light is irradiated onto the anterior segment of the eye under examination and then onto the posterior segment via the pupil 27. The measurement light reflected from the anterior or posterior segment is incident on the OCT unit 20 via the imaging optical system 116A, and then incident on the second optical coupler 20F via the collimator lens 20E and the first optical coupler 20C. In this embodiment, an SD-OCT using an SLD as the light source 20A is exemplified, but the invention is not limited to this, and an SS-OCT using a wavelength-swept light source instead of an SLD may also be employed.

[0024] The other beam of light emitted from the light source 20A and branched by the first optical coupler 20C is incident on the reference optical system 20D as reference light, and then, via the reference optical system 20D, is incident on the second optical coupler 20F.

[0025] The measurement light (return light) reflected and scattered by the eye under examination 12 and the reference light are combined by the second optical coupler 20F to generate interference light. The interference light is detected by the sensor 20B. The image processing device 17 generates a tomographic image of the eye under examination 12 based on the detection signal (OCT data) from the sensor 20B.

[0026] In this embodiment, the OCT system generates tomographic images of the anterior or posterior segment of the eye 12 being examined.

[0027] The anterior segment of the eye under examination 12 includes, for example, the cornea, iris, iridocorneal angle, lens, ciliary body, and a portion of the vitreous humor. The posterior segment of the eye under examination 12 includes, for example, the remaining portion of the vitreous humor, retina, choroid, and sclera. The vitreous humor belonging to the anterior segment is the portion of the vitreous humor on the corneal side, with the XY plane passing through the point of the lens closest to the center O of the eyeball as the boundary, while the vitreous humor belonging to the posterior segment is the portion of the vitreous humor other than that belonging to the anterior segment.

[0028] When the anterior segment of the eye 12 under examination is the target area for imaging, the OCT system generates, for example, a tomographic image of the cornea. When the posterior segment of the eye 12 under examination is the target area for imaging, the OCT system generates, for example, a tomographic image of the retina.

[0029] The ophthalmic optical device 110 includes a fixation target control device 90 that lights up a fixation target, which is composed of a light-emitting device (e.g., an LED) that is turned on to direct the line of sight of the eye under examination 12 in a predetermined direction.

[0030] Figure 2A shows the schematic configuration of the imaging optical system 116A during posterior segment observation, and Figure 2B shows the schematic configuration of the imaging optical system 116A during anterior segment observation. The imaging optical system 116A comprises an objective lens 130, a dichroic mirror 178 which is an optical path combining member, a horizontal scanning unit 142, a relay lens device 140, a dichroic mirror 147, vertical scanning units 120 and 168, and a focus adjustment device 150, all arranged in order from the eye under examination 12 side. The objective lens 130 is an example of the "objective optical system" of the present disclosure, and the focus adjustment device 150 is part of the "optical guide optical system" of the present disclosure.

[0031] The dichroic mirror 178 is an optical element that combines the light emitted from the SLO optical system, the light emitted from the OCT optical system, and the light from the fixation target emitted from the fixation target projection system 138. As shown in Figures 2A and 2B, the dichroic mirror 178 transmits the light emitted from the SLO optical system and the light emitted from the OCT optical system, while reflecting the light from the fixation target emitted from the fixation target projection system 138, and guides the light emitted from the SLO optical system, the light emitted from the OCT optical system, and the light from the fixation target emitted from the fixation target projection system 138 to the objective lens 130.

[0032] The fixation target projection system 138 includes a fixation target 138A and a focusing lens 138B that supplies light from the fixation target 138A toward the fundus of the eye under examination 12. By moving the fixation target 138A and the focusing lens 138B integrally along the optical axis 138C of the fixation target projection system 138, it corresponds to posterior segment observation and anterior segment observation. The fixation target projection system 138 is an example of a "fixation target optical system" of the technology of this disclosure.

[0033] The horizontal scanning unit 142 is an optical scanner that scans the laser light of the SLO and the measurement light of the OCT, both incident via the relay lens device 140, in the horizontal direction.

[0034] The focus adjustment device 150, which receives measurement light emitted from the end 158 of the fiber through which light emitted from the OCT unit 20 travels, is equipped with multiple lenses 152 and 154. Depending on the imaging area of ​​the eye under examination 12, the focus position of the measurement light in the eye under examination 12 is adjusted by appropriately moving each of the multiple lenses 152 and 154 in the optical axis direction. For example, in Figure 2A, the fundus, which is the posterior segment of the eye under examination 12, and in Figure 2B, the cornea, which is the anterior segment of the eye under examination 12, are moved in the optical axis direction as appropriate so that they become the focus position of the OCT measurement light. Although not shown, if a focus detection device is provided, it is possible to realize an autofocus device by driving the lenses 152 and 154 in the focus adjustment device according to the focus detection status to automatically adjust the focus.

[0035] The vertical scanning unit 168 is an optical scanner that scans the OCT measurement light incident via the focus adjustment device 150 in the vertical direction.

[0036] The vertical scanning unit 120 is an optical scanner that scans the laser light incident from the SLO unit 18 in the vertical direction.

[0037] The relay lens device 140 comprises multiple positive power lenses 144 and 146. The relay lens device 140 is configured such that the position of the vertical scanning unit 168 and the position of the horizontal scanning unit 142 are conjugate, and the position of the vertical scanning unit 120 and the position of the horizontal scanning unit 142 are conjugate. More specifically, the relay lens device 140 is configured such that the center positions of the angular scanning of both scanning units are conjugate. As shown in Figure 2A, in the posterior eye observation state, the focus adjustment device 150 forms the focal point of the measurement light emitted from the end 158 of the fiber between lens 146 and lens 144, which are two groups of positive lenses in the relay lens device 140. Furthermore, as shown in Figure 2B, in the anterior segment observation state, the focus adjustment device 150 causes the luminous beam of measurement light emitted from the end 158 of the fiber to become approximately parallel between lens 146 and lens 144, which are two positive lens groups in the relay lens device 140.

[0038] The dichroic mirror 147 is positioned between lens 144 and lens 146 of the relay lens device 140. The dichroic mirror 147 reflects the SLO light emitted from the SLO unit 18 through lens 144 toward the horizontal scanning unit 142. The light emitted from the SLO unit 18 is scanned in two dimensions by the vertical scanning unit 120 and horizontal scanning unit 142 that constitute the SLO optical system. The two-dimensionally scanned SLO laser light is incident on the eye under examination 12 via the objective lens 130. The SLO laser light reflected from the eye under examination 12 is incident on the SLO unit 18 via the objective lens 130, dichroic mirror 178, horizontal scanning unit 142, lens 144 which is part of the positive lens group in the relay lens device 140, the dichroic mirror 147, and vertical scanning unit 120.

[0039] The measurement light emitted from the OCT unit 20 is scanned in two dimensions by the focus adjustment device 150 and the vertical scanning unit 168, passes through the dichroic mirror 147, and is scanned in two dimensions by the horizontal scanning unit 142 in a direction perpendicular to the scanning direction of the vertical scanning unit 168, resulting in a two-dimensional scan. The OCT measurement light reflected from the eye under examination 12 is incident on the OCT unit 20 via the objective lens 130, dichroic mirror 178, horizontal scanning unit 142, relay lens device 140, dichroic mirror 147, vertical scanning unit 168, and focus adjustment device 150.

[0040] Suitable examples of the horizontal scanning unit 142 and the vertical scanning units 120 and 168 include, for example, a resonant scanner, a galvanometer mirror, a polygon mirror, a rotating mirror, a dove prism, a double dove prism, a rotation prism, a MEMS mirror scanner, and an acousto-optic element (AOM). In this embodiment, a galvanometer mirror is used as the vertical scanning unit 168, and a polygon mirror is used as the vertical scanning unit 120. If a two-dimensional optical scanner such as a MEMS mirror scanner is used instead of an optical scanner such as a polygon mirror or a galvanometer mirror, the relay lens device 140 may be omitted because the incident light can be angularly scanned two-dimensionally by its reflective element. Also, if the vertical scanning units 120 and 168 are configured to scan in the horizontal direction as well, the horizontal scanning unit 142 may be omitted.

[0041] The vertical scanning units 120, 168 and the horizontal scanning unit 142, under the control of the CPU 16A, scan the eye 12 with the scanning beam within a range of scanning angles of the scanning beams from the vertical scanning units 120, 168 and the horizontal scanning unit 142, which is set according to the scanning range of the eye 12 under examination. The CPU 16A is an example of a "scanning member control unit" of the technology disclosed herein.

[0042] The objective lens 130 comprises a first lens group 132 and a second lens group 134, in order from the horizontal scanning unit 142 side. The second lens group 134 has the function of outputting ultra-wide-angle scanning light toward the pupil of the eye under examination 12. The first lens group 132 and the second lens group 134 together constitute a positive lens group with positive power. The first lens group 132 is an example of the "first positive lens group" of the technology disclosed herein, and the second lens group 134 is an example of the "second positive lens group" of the technology disclosed herein.

[0043] The light beam from the fixation target projection system 138 passes through the objective lens 130 via reflection by the dichroic mirror 178 and becomes a parallel light beam directed toward the eye under examination 12. This allows the eye under examination 12 to gaze at the image of the fixation target, and by changing the position of the fixation target, the orientation of the eye under examination 12 can be changed, making it possible to photograph the required areas of the posterior and anterior segments of the eye under examination 12. In this embodiment, as will be described later, the working distance WD, which is the distance between the objective lens 130 and the eye under examination 12, changes when observing the posterior segment and when observing the anterior segment. In this embodiment, as shown in Figures 2A and 2B, the change in working distance WD is addressed by changing the distance between the fixation target projection system 138 and the dichroic mirror 178.

[0044] Furthermore, the objective optical system may consist not only of the objective lens 130 shown in Figures 2A and 2B, but also of an optical system including a reflecting mirror such as a concave elliptical mirror.

[0045] Next, with reference to Figures 3A, 3B, and 3C, the state of the imaging optical system 116A centered on the objective lens 130 during posterior segment observation, anterior segment observation, and intraocular observation will be described. Figure 3A is a schematic optical path diagram showing the state of the optical system centered on the objective lens 130 during posterior segment observation, Figure 3B during anterior segment observation, and Figure 3C during intraocular observation. In this embodiment, the distance between the objective lens 130 and the eye under examination 12 is adjusted according to the image conjugate position changed by the upstream optical system equipped with a focus adjustment device 150. This upstream optical system corresponds to a light guide optical system that guides the light beam from the light source to the scanning unit.

[0046] Figure 3A shows the posterior segment observation, illustrating how three parallel beams of light at different angles, supplied from the scanning plane represented by the horizontal scanning unit 142, are focused at the fundus 12A of the eye under examination 12 through two positive lens groups (first lens group 132 and second lens group 134). These three angled beams are shown as examples of scanning beams from only one of the two-dimensional scanning methods: vertical scanning by the vertical scanning units 120 and 168, and two-dimensional scanning by the horizontal scanning unit 142. The circular arrows in the figure indicate the direction of angular scanning of the scanning light by the scanning unit and the direction of angular scanning on the eye under examination side, respectively. The same applies to Figures 3B and 3C below.

[0047] During posterior segment observation, the vertical scanning units 120, 168 and the horizontal scanning unit 142 are positioned at the pupil conjugate position 180 shown in Figure 3A so as to be conjugate to the pupil position Pp of the eye under examination 12. The pupil conjugate position 200, where the conjugate images of the vertical scanning units 120, 168 and the horizontal scanning unit 142 are formed, coincides with the pupil position Pp of the eye under examination. Furthermore, the fundus image of the eye under examination 12 is formed at position 210 between the first lens group 132 and the second lens group 134. That is, the surface 182 in contact with the fundus of the eye under examination 12 and the surface at position 210 are geometrically optically conjugate. In the state shown in Figure 3A, the working distance WD is approximately equal to the distance between the second lens group 134 of the objective lens 130 and the pupil conjugate position 200.

[0048] During posterior segment observation, the SLO laser light scanned by the vertical scanning unit 120 and the horizontal scanning unit 142 in the SLO optical system of the eye under examination is angularly scanned two-dimensionally around the pupil position Pp of the eye under examination 12 via the objective lens 130. As a result, the focal point of the SLO laser light is scanned two-dimensionally in the fundus 12A. Similarly, during posterior segment observation, the measurement light scanned by the vertical scanning unit 168 and the horizontal scanning unit 142 in the OCT optical system is angularly scanned two-dimensionally around the pupil position Pp of the eye under examination 12 via the objective lens 130. As a result, the focal point of the measurement light is scanned two-dimensionally in the fundus 12A. During posterior segment observation, a two-dimensional fundus image is acquired by the SLO unit 18, and a fundus tomographic image is acquired by the OCT unit 20.

[0049] In the anterior segment observation shown in Figure 3B, the same three angled light beams supplied from the horizontal scanning unit 142 are focused onto the cornea of ​​the eye under examination 12 by two positive lens groups (first lens group 132 and second lens group 134).

[0050] During anterior segment observation, similar to posterior segment observation, the vertical scanning units 120, 168 and horizontal scanning unit 142 are positioned at the pupil conjugate position 180 shown in Figure 3B so as to be conjugate to the pupil position Pp of the eye under examination 12. However, the pupil conjugate position 202, where the conjugate images of the vertical scanning units 120, 168 and horizontal scanning unit 142 are formed, does not coincide with the pupil position Pp of the eye under examination, but is formed between the eye under examination and the second lens group 134. In addition, an image conjugate position 212, where the anterior segment image of the eye under examination 12 is formed, is formed between the first lens group 132 and the pupil conjugate position 180, and an image conjugate position 184 is formed on the surface in contact with the anterior end of the eye under examination 12. In the state shown in Figure 3B, the working distance WD is greater than the distance between the second lens group 134 of the objective lens 130 and the pupil conjugate position 202. As mentioned above, the pupil conjugate position 180 is the conjugate position with the scanning units 120, 142, and 168. It coincides with the pupil Pp of the eye under examination 12 during posterior segment observation, but does not coincide with the pupil Pp of the eye under examination 12 during anterior segment observation, as shown in Figure 3B. To facilitate comparison with the optical configuration during fundus observation, the conjugate position with the scanning unit may be referred to as the pupil conjugate position from now on.

[0051] During anterior segment observation, in the SLO optical system of the eye under examination, the SLO laser light scanned by the vertical scanning unit 120 and the horizontal scanning unit 142 passes through the objective lens 130 and is angularly scanned two-dimensionally around the pupil conjugate position 202. As a result, the focal point of the SLO laser light is scanned two-dimensionally in the anterior segment. Similarly, during anterior segment observation, in the OCT optical system, the measurement light scanned by the vertical scanning unit 168 and the horizontal scanning unit 142 passes through the objective lens 130 and is angularly scanned two-dimensionally around the pupil conjugate position 202, and the focal point of the OCT measurement light is scanned two-dimensionally in the anterior segment of the eye under examination 12.

[0052] In the observation of the inside of the eyeball shown in Figure 3C, the same three angled light beams supplied from the horizontal scanning unit 142 are focused onto the crystalline lens 12L of the eye under examination 12 by the objective lens 130, which has two positive lens groups (first lens group 132 and second lens group 134).

[0053] During internal ocular observation, similar to posterior segment observation, the vertical scanning units 120, 168 and horizontal scanning unit 142 are positioned at the pupil conjugate position 180 shown in Figure 3C so as to be conjugate to the pupil position Pp of the eye under examination 12. However, the pupil conjugate position 204, where the conjugate images of the vertical scanning units 120, 168 and horizontal scanning unit 142 are formed, does not coincide with the pupil position Pp of the eye under examination, but is formed between the eye under examination and the second lens group 134. In addition, an image conjugate position 214 is formed between the first lens group 132 and the second lens group 134, and an image conjugate position 186 is formed on the surface in contact with the posterior end of the crystalline lens 12L of the eye under examination 12. In the state shown in Figure 3C, the working distance WD is greater than the distance between the second lens group 134 of the objective lens 130 and the pupil conjugate position 204, but not as much as in the case of Figure 3B. That is, it is the value between the working distance WD in the posterior segment observation state shown in Figure 3A and the working distance WD in the anterior segment observation state shown in Figure 3B. In this embodiment, it is possible to continuously change the working distance WD from the state shown in Figure 3A, through the state shown in Figure 3C, to the state shown in Figure 3B.

[0054] During internal ophthalmoscopic observation, the SLO laser light scanned by the vertical scanning unit 120 and the horizontal scanning unit 142 in the SLO optical system of the eye under examination is angularly scanned two-dimensionally around the pupil conjugate position 204 via the objective lens 130. As a result, the focal point of the SLO laser light is scanned two-dimensionally inside the eye under examination. Similarly, during internal ophthalmoscopic observation, the measurement light scanned by the vertical scanning unit 168 and the horizontal scanning unit 142 in the OCT optical system is angularly scanned two-dimensionally around the pupil conjugate position 204 via the objective lens 130, and the focal point of the measurement light scans inside the eye under examination. This makes it possible to observe any position inside the eye between the fundus and the cornea of ​​the eye under examination.

[0055] As shown in Figures 3A, 3B, and 3C, respectively, the vertical scanning units 120, 168 and the horizontal scanning unit 142 are angularly scanned in the direction of arrow 190. Due to this angular scanning, the light beam that has passed through the objective lens 130 changes its optical path in the direction of arrow 192, passes through pupil conjugate positions 200, 202, and 204, and scans the posterior segment of the eye under examination 12 in the direction of arrow 194. In this embodiment, the scanning direction of the vertical scanning units 120, 168 and the horizontal scanning unit 142 is the same whether observing the posterior segment, anterior segment, or inside the eyeball, and the direction in which the SLO laser light and the OCT measurement light scan the eye under examination 12 is the same. As a result, in image processing, image inversion processing is not required regardless of whether it is observing the posterior segment, anterior segment, or inside the eyeball. Therefore, in all observations of the anterior, intermediate, and posterior segments of the eye under examination, the scanning direction remains constant, and the positional relationship between the observer and the resulting image does not change, resulting in improved operability without practical confusion.

[0056] The method for switching the focus of the focus adjustment device 150 from posterior segment observation to anterior segment observation is as follows:

[0057] (1) The optical system of the focus adjustment device 150 is configured to be interchangeable between an optical system for posterior segment observation and an optical system for anterior segment observation. (2) The focus adjustment device 150 normally has an optical system that corresponds to posterior segment observation, and can be adapted to anterior segment observation by adding an optical system that can be inserted and removed when observing the anterior segment. Alternatively, the focus adjustment device 150 normally has an optical system that corresponds to anterior segment observation, and can be adapted to posterior segment observation by adding an optical system that can be inserted and removed when observing the posterior segment. (3) The focus adjustment device 150 is configured such that the distance between the optical system of the focus adjustment device 150 and the vertical scanning unit 168 can be changed. (4) The optical system of the focus adjustment device 150 is configured such that the focal length of the optical system of the focus adjustment device 150 can be changed. For example, the optical system of the focus adjustment device 150 is configured with a zoom lens or a liquid lens, etc.

[0058] FIG. 4A is an explanatory diagram of the calculation of the ray angle at the positions of the vertical scanning units 120 and 168 and the horizontal scanning unit 142 (scanner positions) existing at the pupil conjugate position 180 during anterior eye observation. In FIG. 4A, θ A is the ray angle at the scanner position, and θ A ’ is the ray angle after being emitted from the objective lens 130, and WD P is the working distance during posterior eye scan, and WD A is the working distance during anterior eye scan.

[0059] Also, when the angular magnification of the objective lens 130 during anterior eye scan is M A , the following relationship of formula (1) holds. The working distances WD A , WD P , and M A are each numerical values specific to the imaging optical system 116A. M A = θ A ’ / θ A …(1)

[0060] If the length to be scanned on the anterior eye is L A , the following formula (2) holds. L A is determined based on the image of the anterior eye obtained in advance and presented to the subject, and the scanning range indicated by the subject on the screen, as will be described later. L A / 2 = (WD A - WD P ) tanθ A ’ …(2)

[0061] From formula (1) and formula (2), the ray angle θ A at the scanner position is calculated by the following formula (3). In this embodiment, angular scanning in OCT is performed based on the calculated ray angle θ A . θ A = arctan {L A / 2 * (WD A - WD P )} / M A …(3)

[0062] Figure 4B is an explanatory diagram for calculating the ray angle at the scanner position located at the pupil conjugate position 180 during internal observation of the eyeball. In Figure 4B, θ M θ is the angle of light rays at the scanner position. M ' is the angle of the light rays after they are emitted from the objective lens 130, WD P This is the working distance during posterior segment scanning, G A This is a refractive system in which the anterior segment of the eye 12 under examination is considered as a single thin lens, and WD M This is the working distance during an internal eyeball scan, specifically from the objective lens 130 to the refractive system G A This is the distance to [the point]. And the refractive system G A The focal length of f A , refractive system G A The refractive index on the posterior segment is n A Let's assume that.

[0063] Figure 4B shows a scan of the inside of the eyeball, so the part actually scanned is from the objective lens 130 to WD. M This corresponds to the position of +s.

[0064] Furthermore, the angular magnification during the internal scanning of the eyeball with objective lens 130 is M M Therefore, equation (4) below holds true. M M =θ M ' / θ M …(4)

[0065] The length you want to scan inside the eyeball is L M Therefore, equation (5) below holds true. L M / 2 = s * tanθ M '×(1-s / S') …(5) However, S' = n A ' / {1 / (WD M -WD P ) + 1 / f A} is.

[0066] Equations (4) and (5) give the ray angle θ at the scanner position. M This is calculated using the following formula (6). θM =arctan[L M / {2*s*(1-s / S')}] / M M …(6) (S'= n A ' / {1 / (WD M -WD P ) + 1 / f A} )

[0067] Next, referring to Figures 5A and 5B, the state of the imaging optical system 116A, centered on the fixation target projection system 138 and the objective lens 130, during posterior segment observation and anterior segment observation will be explained. Figure 5A shows the state of the optical system centered on the fixation target projection system 138 and the objective lens 130 during posterior segment observation, and Figure 5B shows the state of the optical system during anterior segment observation. In Figures 5A and 5B, for explanatory purposes, the optical path diagram is shown as an unfolded optical path diagram centered on the objective lens 130. The fixation target 138A of the fixation target projection system 138 shown in Figures 2A and 2B is placed on the left end face 220 of the figure, and the condensing lens 138B of the fixation target projection system 138 is also shown as positive lenses 224 and 226. The face 220 on which the fixation target is placed corresponds to the focal position of the positive lens 224, and the light rays from the fixation target become nearly parallel beams, which are supplied to the eye side as parallel beams by the objective lens 130. The light then enters the eye under examination and is focused on the fundus of that eye. The vertical dashed line in the diagram indicates the pupillary conjugate position as mentioned earlier, for reference.

[0068] In the posterior segment observation shown in Figure 5A, the fixation target projection system 138 is positioned on a plane 220 corresponding to the conjugate position with the fundus. The image of the fixation target 138A is formed at the fundus conjugate position 228 between the first lens group 132 and the second lens group 134, and further, the plane in contact with the fundus of the eye under examination 12 is formed as a conjugate position 236, allowing the eye under examination 12 to recognize the fixation target.

[0069] In the fixation target projection system, the fixation target is placed at the position shown as surface 220, and light from this fixation target is supplied to the subject 12 along the optical path shown in Figure 5A, without requiring a separate scanning unit. However, the illustration shows light beams from three points on the fixation target: one on the axis and two off-axis points. By placing point light sources such as LEDs at these three points and independently switching them on and off, it is possible to change the orientation of the subject eye 12. This configuration makes it possible to observe the peripheral part of the subject eye 12, and as a result, it becomes possible to observe a wider area of ​​the subject eye.

[0070] Even during anterior segment observation as shown in Figure 5B, the fixation target 138A of the fixation target projection system 138 is positioned at the illustrated image conjugate position 222, and the light beam from the positive lens 226 is nearly parallel, similar to the posterior segment observation. As can be seen from the comparison with the configuration shown in Figure 5A, the plane 220 on which the fixation target is placed and the positive lens 224 have moved together toward the objective lens 130. Therefore, with respect to the objective lens 130, the conjugate position near the positive lens 226, indicated by the vertical dashed line, becomes conjugate at position 234 on the subject eye 12 side, which is further away from position 232 in Figure 5A. This corresponds to a larger working distance in the anterior segment observation state (Figure 5B) compared to the posterior segment observation state (Figure 5A).

[0071] During anterior segment observation, the light beam emitted from the fixation target projection system 138 passes through the orthogonal lens 226 at the pupil conjugate position, enters the first lens group 132, passes through the image conjugate position 230, and exits from the second lens group 134. Then, it passes through position 234, which is a conjugate position formed between the second lens group 134 and the eye under examination 12, and enters the eye under examination 12. Furthermore, the surface in contact with the fundus of the eye under examination 12 is formed as a conjugate position 238, and the fixation target is recognized by the eye under examination 12.

[0072] As described above, when observing the anterior segment, the distance between the second lens group 134 of the objective lens 130 and the eye under examination 12 is increased compared to when observing the posterior segment. Therefore, the distance between the fixation target projection system 138 and the objective lens 130 is changed to correspond to this increase in distance. In this embodiment, when observing the anterior segment, the optical distance between the fixation target projection system 138 and the first lens group 132 of the objective lens 130 is shortened compared to when observing the posterior segment, thereby corresponding to the increase in the distance between the second lens group 134 of the objective lens 130 and the eye under examination 12.

[0073] Figure 6 is a flowchart showing an example of processing in the ophthalmic optical device 110 according to this embodiment. The processing shown in Figure 6 is initiated, for example, when the OCT unit 20 of the ophthalmic optical device 110 takes an image of the eye under examination 12.

[0074] Step 600 determines whether an instruction to observe the anterior segment of the eye has been given. If an instruction to observe the anterior segment of the eye has been given in Step 600, the procedure proceeds to Step 602; if an instruction to observe the anterior segment of the eye has not been given, the procedure proceeds to Step 620.

[0075] Step 602 ensures the distance between the objective optical system (objective lens 130) and the eye under examination 12 for anterior segment observation. Specifically, the distance between the objective optical system and the eye under examination is set to the working distance WD corresponding to that for posterior segment observation. P In that case, the working distance WD corresponds to the distance when observing the anterior segment. A To achieve this, the working distance (WD) between the objective optical system and the eye under examination during anterior segment observation is set. A and working distance WD during posterior segment observation P The difference is WD A -WD P Enlarge.

[0076] The method for adjusting the distance between the objective optical system and the eye under examination 12 is as follows, for example. (1) Move the imaging optical system 116A to control the working distance WD A Secure it. (2) Move the entire ophthalmic optical device 110 to the working distance WD A Secure it. (3) Move the chin rest that holds the subject's chin, or the headrest that holds the subject's head, to control the working distance WD A Secure it.

[0077] The movement of the imaging optical system 116A, the entire ophthalmic optical device 110, the chin rest, and the headrest may be driven by a motor or moved manually. Alternatively, the chin rest and headrest may be prepared in advance with thicknesses corresponding to posterior segment observation and thicknesses corresponding to anterior segment observation, and they may be swapped as needed. Preferably, the objective optical system is moved by a motor.

[0078] In step 604, the fixation target projection system 138 is set to a position corresponding to the anterior segment scan. Specifically, as shown in Figure 5B, during anterior segment observation, the optical distance between the fixation target projection system 138 and the first lens group 132 of the objective lens 130 is reduced compared to posterior segment observation, thereby corresponding to the increased distance between the second lens group 134 of the objective lens 130 and the eye under examination 12.

[0079] In step 606, the focus adjustment device 150 is used to switch the focus of the OCT scan to the anterior segment position. Specifically, as shown in Figure 3B, the image conjugate position 184 is formed on the surface in contact with the anterior end of the eye under examination 12.

[0080] Step 608 involves setting the scanning angle. Specifically, the previously acquired anterior segment image is displayed on a screen visible to the subject, and the subject is asked to indicate the area to be scanned. Then, based on the area indicated by the subject and the scan pattern (e.g., 3D scan or linear scan), the desired length L of the anterior segment to be scanned is determined. A Calculate the length L. A The ray angle θ at the scanner position is given by the above equation (3) and the ray angle θ at the scanner position. A This is automatically calculated and set as the scan angle.

[0081] In step 610, the OCT scan is started according to the set scanning angle. Then, in step 612, the focus position is measured at any number of points in the anterior segment, and the shape of the cornea is calculated.

[0082] In step 614, an OCT scan is performed using the instructed scan pattern and scan range while adjusting the focus to match the corneal shape.

[0083] Step 616 determines whether to terminate the OCT scan. In Step 616, the OCT scan is terminated if the entire scan range specified by the set scan pattern has been scanned. However, the OCT scan is also terminated if the physician determines that it is not necessary to scan the entire specified scan range. If the OCT scan is terminated in Step 616, the procedure proceeds to Step 618. If the OCT scan is not terminated, the procedure proceeds to Step 610.

[0084] In step 618, image processing for the anterior segment is performed, the results are displayed, and the process is terminated. Specifically, OCT image data for the anterior segment is generated from image data obtained by the OCT scan by performing noise reduction and other processing.

[0085] If there was no instruction for anterior segment observation in step 600, step 620 ensures the distance between the objective optical system and the eye under examination 12 for posterior segment observation. Specifically, the distance between the objective optical system and the eye under examination is set to the working distance WD corresponding to posterior segment observation. P Set to this.

[0086] The method for adjusting the distance between the objective optical system and the eye under examination 12 is the same as when observing the anterior segment, as follows: (1) Move the imaging optical system 116A to control the working distance WD P Secure it. (2) Move the entire ophthalmic optical device 110 to the working distance WD P Secure it. (3) Move the chin rest that holds the subject's chin, or the headrest that holds the subject's head, to control the working distance WD P Secure it.

[0087] The movement of the imaging optical system 116A, the entire ophthalmic optical device 110, the chin rest, and the headrest may be driven by a motor or moved manually. Alternatively, the chin rest and headrest may be prepared in advance with thicknesses corresponding to posterior segment observation and thicknesses corresponding to anterior segment observation, and they may be swapped as needed. Preferably, the objective optical system is moved by a motor, similar to the method used for anterior segment observation.

[0088] In step 622, the fixation target projection system 138 is set to a position corresponding to the posterior segment scan. Specifically, as shown in Figure 5A, during posterior segment observation, the optical distance between the fixation target projection system 138 and the first lens group 132 of the objective lens 130 is increased compared to anterior segment observation, thereby corresponding to the reduction in the distance between the second lens group 134 of the objective lens 130 and the eye under examination 12.

[0089] In step 624, the focus adjustment device 150 is used to switch the focus of the OCT scan to the posterior segment position. Specifically, as shown in Figure 3A, the image conjugate position is formed on the surface 182 that is in contact with the posterior end of the eye under examination 12.

[0090] In step 626, the scan pattern and scan range are set. Specifically, the previously acquired images of the posterior segment are displayed on a screen that the subject can view, and the subject is asked to indicate the area to be scanned.

[0091] In step 628, the OCT scan is initiated. Then, in step 630, the focal points at any number of points in the posterior segment are measured, and the shape of the retina is calculated.

[0092] In step 632, an OCT scan is performed using the instructed scan pattern and scan range while adjusting the focus to match the retinal shape. As mentioned above, in this embodiment, the scanning direction of the vertical scanning units 120, 168 and the horizontal scanning unit 142 is the same whether observing the posterior segment, anterior segment, or inside the eyeball, and the direction in which the SLO laser light and the OCT measurement light scan the eye under examination 12 is the same. As a result, in image processing, image inversion processing is not required regardless of whether it is observing the posterior segment, anterior segment, or inside the eyeball.

[0093] Step 634 determines whether to terminate the OCT scan. In Step 616, the OCT scan is terminated if the entire scan range specified by the set scan pattern has been scanned. However, the OCT scan is also terminated if the physician determines that it is not necessary to scan the entire specified scan range. If the OCT scan is terminated in Step 634, the procedure proceeds to Step 636. If the OCT scan is not terminated, the procedure proceeds to Step 628.

[0094] In step 636, image processing for the posterior segment is performed, the results are displayed, and the process is terminated. Specifically, OCT image data for the posterior segment is generated by performing noise reduction and other processing on the image data obtained from the OCT scan.

[0095] Next, the adjustment of the positional relationship between the objective lens 130 and the eye under examination 12 in the ophthalmic optical device 110 according to this embodiment, i.e., alignment, will be described. In order to accurately position the observation area, the ophthalmic optical device 110 requires adjustment of the horizontal and vertical positional relationship of the eye under examination 12 with respect to the optical axis of the objective lens 130 of the ophthalmic optical device, as well as the distance from the objective lens 130, i.e., focus adjustment.

[0096] Figure 7A is a lateral view of the optical system configuration for alignment of the ophthalmic optical device 110 during posterior segment observation, and Figure 7B is a lateral view of the optical system configuration for alignment of the ophthalmic optical device 110 during posterior segment observation, showing the viewpoint shifted 90° upward from Figure 7A. Note that the rays shown are only the principal rays of the off-axis luminous flux for alignment.

[0097] As shown in Figures 7A and 7B, light from the eye under examination 12 reaches the dichroic mirror 178 via the second lens group 132 and the first lens group 134 of the objective lens 130. The light that reaches the dichroic mirror 178 is reflected by the dichroic mirror 178 and incident on the image sensors 244A and 244B of the pair of eye position detection optical systems 240A and 240B, which are arranged symmetrically on either side of the optical axis 196, via the focusing lenses 242A and 242B of the eye position detection optical systems 240A and 240B, respectively. The image sensors 244A and 244B form an image of the eye under examination 12, and it is possible to detect the position of the eye under examination 12 from the position of these images.

[0098] The configuration in this embodiment, which detects the position of the eye under examination through the objective lens 130, can be described as a through-the-lens (TTL) alignment system. This configuration, which detects the position of the eye under examination through the objective lens 130, is effective when the working distance becomes extremely small when using a wide-angle objective lens to obtain a wide-angle fundus image. It is particularly useful in ultra-wide-angle fundus observation devices with a field of view exceeding 130 degrees, where the working distance is approximately 20 mm. In such a TTL alignment system, the second lens group 134 on the eye under examination outputs wide-angle scanning light towards the pupil of the eye under examination 12. As shown in the optical path diagram in Figure 7B, the angle of the principal ray with respect to the anterior segment of the eye under examination 12 becomes larger, improving the accuracy of alignment position detection. Needless to say, this configuration is more advantageous with UWF objective lenses.

[0099] In this embodiment, under the control of the CPU 16A, the distance between the objective lens 130 and the eye under examination 12 in the optical axis direction 196 can be calculated from images acquired by a pair of left and right image sensors 244A and 244B.

[0100] Figure 8A is a lateral view of the optical system configuration for alignment of the ophthalmic optical device 110 during anterior segment observation, and Figure 8B is a lateral view of the optical system configuration for alignment of the ophthalmic optical device 110 during anterior segment observation, showing the viewpoint shifted 90° upward from Figure 8A. Note that the rays shown are only the principal rays of the off-axis luminous flux for alignment.

[0101] As described above, when observing the anterior segment of the eye, the distance between the second lens group 134 of the objective lens 130 and the eye under examination 12 is increased compared to when observing the posterior segment. Therefore, the distance between the eye position detection optical systems 240A and 240B and the objective lens 130 is changed to correspond to this increase in distance. In this embodiment, when observing the anterior segment of the eye, the optical distance between the eye position detection optical systems 240A and 240B and the first lens group 132 of the objective lens 130 is shortened compared to when observing the posterior segment, thereby accommodating the increase in the distance between the second lens group 134 of the objective lens 130 and the eye under examination 12.

[0102] Figure 9 is a lateral view of the optical path of another configuration of the optical system related to the alignment of the ophthalmic optical device 110 during posterior segment observation. In Figure 9, the eye position detection optical systems 250A and 250B are each positioned between the objective lens 130 and the eye 12. As shown in Figure 9, light from the eye 12 bypasses the objective lens 130 and enters the image sensors 254A and 254B of the pair of eye position detection optical systems 250A and 250B, which are arranged symmetrically on either side of the optical axis 196, via the focusing lenses 252A and 252B of the eye position detection optical systems 250A and 250B, respectively. The image sensors 254A and 254B form images of the eye 12, and it is possible to detect the position of the eye 12 from the position of these images. Each of the eye position detection optical systems 240A, 240B, 250A, and 250B is an example of an "eye position detection device" of the technology of this disclosure.

[0103] Figure 10 is a lateral view of the optical system configuration related to the alignment of the ophthalmic optical device 110 during anterior segment observation. As mentioned above, during anterior segment observation, the distance between the second lens group 134 of the objective lens 130 and the eye under examination 12 is increased compared to posterior segment observation. Therefore, in response to this increase in distance, the angle of the eye position detection optical systems 250A and 250B with respect to the optical axis 196 is changed to receive light from the eye under examination 12.

[0104] In this embodiment, when observing the anterior segment of the eye, the angle with respect to the optical axis 196 is changed by moving each of the eye position detection optical systems 250A and 250B in the direction indicated by arrow 260, compared to when observing the posterior segment, corresponding to an increase in the distance between the second lens group 134 of the objective lens 130 and the eye 12 under examination.

[0105] Regarding the alignment systems of the eye under examination shown in Figures 7A, 7B, 8A, 8B, 9, and 10, the illumination of the eye under examination 12 can be provided by placing an illumination light source at the tip of the objective lens 130. For example, it is possible to place an LED or other light source at a symmetrical position around the optical axis 196 of the objective lens 130, or to place a ring-shaped light source at the tip of the objective lens 130. However, since fundus observation without pupil dilation is possible with the ophthalmic optical device 110 of this embodiment, it is also possible to use only the lighting in the room where the device is installed.

[0106] As described above, in this embodiment, by changing the working distance WD between the objective lens 130 and the eye under examination 12 when observing the posterior segment and when observing the anterior segment, it is not necessary to place a separate lens attachment between the objective lens 130 and the eye under examination 12. In this embodiment, in response to the change in working distance WD, the light beam of the OCT measurement light is adjusted in the focus adjustment device 150, and the optical positions of the fixation target projection system 138 and the eye position detection optical systems 240A, 240B, 250A, and 250B are changed. Furthermore, even if the light beams of the SLO laser light and the OCT measurement light are adjusted in the focus adjustment device 150 in response to the change in working distance WD, the scanning direction of the vertical scanning units 120, 168 and the horizontal scanning unit 142 remains the same, and the direction in which the eye under examination 12 is scanned by the SLO laser light and the OCT measurement light remains the same. As a result, in image processing, image inversion processing is not required depending on whether it is during posterior segment observation, anterior segment observation, or internal ocular observation.

[0107] The configuration of the apparatus in this embodiment described above is merely an example. Therefore, it goes without saying that unnecessary components may be removed or new components added, as long as they do not deviate from the main purpose.

Claims

1. A scanning member that scans the eye under examination with a light beam from a light source, A light guide optical system that guides the light beam from the light source to the scanning member, An objective optical system that guides the scanning beam from the scanning member to the eye under examination, A fixation target optical system for projecting a fixation target onto the eye under examination for fixation of the eye under examination, Equipped with, In the posterior segment imaging state, where the posterior segment of the eye under examination is photographed, The objective optical system focuses the scanning beam from the scanning member, which is positioned at a pupil-conjugate position conjugate to the anterior portion of the eye under examination, onto the posterior portion of the eye under examination. In the anterior segment imaging state, when the anterior segment of the eye under examination is photographed, The objective optical system forms the pupil conjugate position between the anterior portion of the eye under examination and the objective optical system, and focuses the scanning beam from the scanning member onto the anterior portion of the eye under examination, where the working distance, which is the distance between the eye under examination and the objective optical system, is greater than the working distance in the posterior portion imaging state. The fixation target optical system is an ophthalmic optical device that changes the light-gathering position of the fixation target in accordance with the change in the working distance.

2. The ophthalmic optical apparatus according to claim 1, wherein the fixation target optical system comprises the fixation target and a focusing lens that supplies light from the fixation target toward the fundus of the eye to be examined, and the fixation target and the focusing lens are integrally moved along the optical axis of the fixation target optical system.

3. The ophthalmic optical apparatus according to claim 1 or 2, wherein, in the posterior segment imaging state and the anterior segment imaging state, an image of the fixation target is formed between the first positive lens and the second positive lens of the objective optical system.

Images