JP7096391B2 - Ophthalmic equipment - Google Patents

Description

The present invention relates to an ophthalmic apparatus.

Diagnostic imaging occupies an important position in the field of ophthalmology, and in recent years, scanning laser ophthalmoscopes (SLOs) and optical coherence tomography have been increasingly used. The SLO is a device that forms an image by scanning the fundus at high speed with a weak light beam using a cofocal optical system, and is used for screening and diagnosis of eye diseases. Optical coherence tomography is an optical measuring device that applies a technique called optical coherence tomography (OCT), and forms cross-sectional images, three-dimensional images, and functional images by scanning the two-dimensional and three-dimensional regions of the fundus. do. Optical coherence tomography is also used for imaging the cornea and the like.

Generally, the resolution (horizontal resolution) δ of an optical measuring device is represented by δ = 0.61λ / NA (where λ indicates the wavelength of light and NA indicates the numerical aperture of the objective lens). Therefore, the larger the diameter of the beam used for measurement (numerical aperture on the image side), the higher the resolution. That is, the larger the beam diameter, the better the measurement accuracy and the image quality.

Japanese Unexamined Patent Publication No. 2016-54454

When the diameter of the beam used for the measurement is increased, the SNR (Signal-to-Noise Ratio) is improved at the focus position, while the resolution is lowered at the defocus position. However, in the conventional optical measuring device, since the beam diameter incident on the objective lens or the eye to be inspected cannot be changed significantly, it may not be possible to obtain a suitable measurement result depending on the state of the eye to be inspected.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an ophthalmic apparatus capable of obtaining suitable measurement results regardless of the condition of the eye to be inspected.

The first aspect of the ophthalmic apparatus according to the embodiment is an ophthalmologic apparatus that acquires data of an eye to be inspected by a swept source OCT, and uses a light beam as measurement light generated based on light from a wavelength sweep type light source. Data collection using a data collection unit that collects data by scanning the eye to be inspected, a beam size change unit that changes the size of the light beam, and the light beam whose size has been changed by the beam size change. The acquisition unit that acquires the tomographic image of the eye to be inspected based on the data collected by the unit , the evaluation unit that calculates the evaluation value by integrating the pixel values in the depth direction of the tomographic image, and the evaluation value is small. It includes a control unit that controls the beam size changing unit so that the beam diameter of the light beam becomes smaller .
Further , in the second aspect of the ophthalmic apparatus according to the embodiment, in the first aspect , the control unit is linked to the control of changing the size of the light beam by the beam size changing unit from the wavelength sweep type light source. The amount of light of the light may be controlled.
Further , in the third aspect of the ophthalmic apparatus according to the embodiment, in the first aspect or the second aspect , the control unit has the light beam when the evaluation value is the first evaluation value corresponding to the first luminance. The beam size changing unit is controlled so that the size of the light beam becomes the first size, and when the evaluation value is the second evaluation value corresponding to the second brightness lower than the first brightness, the size of the light beam is the first. The beam sizing unit may be controlled so that the second size is smaller than the size.
Further, in the fourth aspect of the ophthalmic apparatus according to the embodiment, in any one of the first to third aspects , a focusing lens arranged in the optical path of the light beam and movable along the optical path. A moving mechanism that moves the focusing lens along the optical path, and the control unit changes the focal position of the light beam to a predetermined position by controlling the moving mechanism, and then the beam. You may control the size change part.
Further , in the fifth aspect of the ophthalmic appliance according to the embodiment, in the first to fourth aspects , the beam size changing unit inserts and removes the diaphragm and the diaphragm with respect to the optical path of the light beam. Demechanism and may be included.
Further, in the sixth aspect of the ophthalmic apparatus according to the embodiment, in the fifth aspect , the data collecting unit divides the light from the light source into the measurement light and the reference light, and the measurement light is used as the light beam. An interference optical system that is incident on the eye to be inspected and detects the interference light between the return light of the measurement light from the eye to be inspected and the reference light, a collimeter lens that makes the measurement light a parallel light beam, and the collimeter lens parallel to each other. The insertion / removal mechanism may insert / remove the aperture with respect to the optical path of the measurement light between the collimator lens and the optical scanner, including an optical scanner that deflects the measurement light as a light beam. ..
Further, in the seventh aspect of the ophthalmic apparatus according to the embodiment, in any one of the first to sixth aspects , the beam size changing unit is a varifocal lens or a zoom arranged in the optical path of the light beam. The control unit may control the varifocal lens or the zoom lens, including the lens.
Further, in the eighth aspect of the ophthalmic apparatus according to the embodiment, in the seventh aspect , the data collecting unit divides the light from the light source into the measurement light and the reference light, and uses the measurement light as the light beam. The varifocal lens includes an interference optical system that is incident on the eye to be inspected and detects the interference light between the return light of the measurement light from the eye to be inspected and the reference light, and an optical scanner that deflects the measurement light. Alternatively, the zoom lens may be arranged between the light source and the optical scanner.
It is possible to arbitrarily combine the configurations according to the plurality of claims described above.

INDUSTRIAL APPLICABILITY According to the present invention, it becomes possible to provide an ophthalmic apparatus capable of obtaining suitable measurement results regardless of the condition of the eye to be inspected.

It is a schematic diagram which shows an example of the structure of the optical system of the ophthalmologic apparatus which concerns on 1st Embodiment. It is a schematic diagram which shows an example of the structure of the optical system of the ophthalmologic apparatus which concerns on 1st Embodiment. It is a schematic diagram which shows an example of the structure of the control system of the ophthalmic apparatus which concerns on 1st Embodiment. It is a flow chart which shows the operation example of the ophthalmic apparatus which concerns on 1st Embodiment. It is a schematic diagram which shows an example of the structure of the optical system of the ophthalmic apparatus which concerns on 2nd Embodiment. It is a schematic diagram which shows an example of the structure of the optical system of the ophthalmic apparatus which concerns on 2nd Embodiment. It is a schematic diagram which shows an example of the structure of the optical system of the ophthalmic apparatus which concerns on 2nd Embodiment. It is a schematic diagram which shows an example of the structure of the control system of the ophthalmic apparatus which concerns on 2nd Embodiment.

An example of an embodiment of the ophthalmic apparatus according to the present invention will be described in detail with reference to the drawings. In addition, the description contents of the document cited in this specification and arbitrary known techniques can be incorporated into the following embodiments.

The ophthalmic apparatus according to the embodiment is an optical measuring device having at least a function of executing OCT and acquiring information about the eye to be inspected by executing OCT on the eye to be inspected as an object to be inspected. Information about the eye to be inspected includes, but is not limited to, a tomographic image and an intraocular distance of the inspected eye such as the axial length. The ophthalmic apparatus according to the embodiment includes an optical system for executing the Fourier domain OCT described later, and has a beam diameter (beam size, light beam diameter, incident light beam diameter, measurement light LS) of the measurement light incident on the eye to be inspected or the objective lens. It is possible to change the diameter in the direction orthogonal to the traveling direction of. For example, the ophthalmic apparatus may change the beam diameter of the measurement light based on the data (scan data) of the eye to be inspected obtained by executing the OCT, or change the beam diameter of the measurement light so as to have the beam diameter specified by the user. It is possible to change the beam diameter. The ophthalmic appliance scans with measurement light with a modified beam diameter and obtains information about the eye to be inspected based on the collected data.

The ophthalmic apparatus according to the embodiment is an ophthalmologic apparatus in which a Fourier domain OCT and a fundus camera having an anterior ocular segment imaging function are combined. This ophthalmic appliance has the ability to perform swept source OCT, but the embodiments are not limited to this. For example, the type of OCT is not limited to swept source OCT, and may be spectral domain OCT or the like. The swept source OCT divides the light from the wavelength sweep type (wavelength scanning type) light source into the measurement light and the reference light, and causes the return light of the measurement light that has passed through the object to be measured to interfere with the reference light to generate interference light. However, this is a method of detecting this interference light with a balanced photodiode or the like. It is possible to form an image by performing a Fourier transform or the like on the detection data collected in response to the wavelength sweep and the scan of the measurement light. Spectral domain OCT divides the light from the low coherence light source into the measurement light and the reference light, and causes the return light of the measurement light that has passed through the object to be measured to interfere with the reference light to generate interference light. This is a method for detecting the spectral distribution with a spectroscope. It is possible to form an image by applying a Fourier transform or the like to the detected spectral distribution.

The ophthalmologic apparatus according to the embodiment may be provided with a scanning laser ophthalmoscope (SLO), a slit lamp microscope, a surgical microscope, a photocoagulation apparatus, or the like, instead of the fundus camera. Hereinafter, in this specification, the image acquired by OCT may be collectively referred to as an OCT image, and the optical path of the measurement light may be referred to as a measurement optical path.

<First Embodiment>
The ophthalmic apparatus according to the first embodiment changes the beam diameter of the measurement light based on the scan data acquired by performing OCT on the eye to be inspected, and uses the measurement light having the changed beam diameter. Obtain information about the eye to be inspected.

[Constitution]
As shown in FIG. 1, the ophthalmic apparatus 1 according to the embodiment includes a fundus camera unit 2, an OCT unit 100, and an arithmetic control unit 200. The fundus camera unit 2 has an optical system substantially similar to that of a conventional fundus camera. The OCT unit 100 is provided with an optical system for executing OCT. The arithmetic control unit 200 includes a processor that executes various arithmetic processes, control processes, and the like.

In the present specification, the "processor" is, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), a programmable logic device (for example, a SPLD (SimpleProgram)). It means a processing circuit including a Programable Logical Device), an FPGA (Field Programgable Gate Array), and the like. The processor realizes the function according to the embodiment by reading and executing a program stored in a storage circuit or a storage device, for example.

[Fundus camera unit]
The fundus camera unit 2 is provided with an optical system for acquiring a two-dimensional image (fundus image) showing the surface morphology of the fundus Ef of the eye to be inspected E. The fundus image includes an observation image, a photographed image, and the like. The observation image is, for example, a monochrome moving image formed at a predetermined frame rate using near-infrared light. The captured image may be, for example, a color image obtained by flashing visible light, or a monochrome still image using near-infrared light or visible light as illumination light. The fundus camera unit 2 may be configured to be capable of acquiring images other than these, such as a fluorescein fluorescent image, an indocyanine green fluorescent image, and a spontaneous fluorescent image.

The fundus camera unit 2 is provided with a chin rest and a forehead pad for supporting the face of the subject. Further, the fundus camera unit 2 is provided with an illumination optical system 10 and a photographing optical system 30. The illumination optical system 10 irradiates the fundus Ef with illumination light. The photographing optical system 30 guides the fundus reflected light of this illumination light to an image pickup device (CCD image sensor (sometimes simply referred to as CCD) 35, 38). Further, the photographing optical system 30 guides the measurement light from the OCT unit 100 to the eye to be inspected E, and guides the measurement light passing through the eye to be inspected E to the OCT unit 100.

The observation light source 11 of the illumination optical system 10 is composed of, for example, a halogen lamp or an LED (Light Emitting Diode). The light output from the observation light source 11 (observation illumination light) is reflected by the reflection mirror 12 having a curved reflecting surface, passes through the condenser lens 13, passes through the visible cut filter 14, and becomes near-infrared light. Become. Further, the observation illumination light is once focused in the vicinity of the photographing light source 15, reflected by the mirror 16, and passes through the relay lenses 17, 18, the diaphragm 19, and the relay lens 20. Then, the observation illumination light is reflected at the peripheral portion of the perforated mirror 21 (the region around the perforated portion), passes through the dichroic mirror 46, is refracted by the objective lens 22, and illuminates the fundus Ef.

The fundus reflected light of the observation illumination light is refracted by the objective lens 22, passes through the dichroic mirror 46, passes through the hole formed in the central region of the perforated mirror 21, passes through the dichroic mirror 55, and focuses on photography. It is reflected by the mirror 32 via the lens 31. Further, the reflected light from the fundus of the eye passes through the half mirror 33A, is reflected by the dichroic mirror 33, and is imaged on the light receiving surface of the CCD image sensor 35 by the condenser lens 34. The CCD image sensor 35 detects the fundus reflected light at a predetermined frame rate, for example. An image (observation image) based on the fundus reflected light detected by the CCD image sensor 35 is displayed on the display device 3. When the photographing optical system 30 is focused on the anterior eye portion, an observation image of the anterior eye portion of the eye E to be inspected is displayed. Hereinafter, the case where the photographing optical system 30 mainly acquires the fundus image of the eye to be inspected E will be described, but it is possible to acquire the anterior eye portion image of the eye to be inspected E in the same manner as the fundus image.

The photographing light source 15 is composed of, for example, a xenon lamp or an LED. The light output from the photographing light source 15 (photographing illumination light) is applied to the fundus Ef through the same path as the observation illumination light. The fundus reflected light of the photographing illumination light is guided to the dichroic mirror 33 through the same path as that of the observation illumination light, passes through the dichroic mirror 33, is reflected by the mirror 36, and is reflected by the condenser lens 37 of the CCD image sensor 38. An image is formed on the light receiving surface. An image (photographed image) based on the fundus reflected light detected by the CCD image sensor 38 is displayed on the display device 3. The display device 3 for displaying the observed image and the display device 3 for displaying the captured image may be the same or different. Further, when the eye E to be inspected is illuminated with infrared light and the same imaging is performed, an infrared captured image is displayed. It is also possible to use an LED as a shooting light source.

The LCD (Liquid Crystal Display) 39 displays a fixative and a visual acuity measurement target. The fixative is a fixative for fixing the eye E to be inspected, and is used at the time of fundus photography, OCT measurement, and the like.

A part of the light output from the LCD 39 is reflected by the half mirror 33A, reflected by the mirror 32, passes through the photographing focusing lens 31 and the dichroic mirror 55, and passes through the hole portion of the perforated mirror 21. The light that has passed through the hole of the perforated mirror 21 passes through the dichroic mirror 46, is refracted by the objective lens 22, and is irradiated to the fundus Ef. By changing the display position of the fixative on the screen of the LCD 39, the fixative position of the eye E to be inspected can be changed.

Further, the fundus camera unit 2 is provided with an alignment optical system 50 and a focus optical system 60, as in the conventional fundus camera. The alignment optical system 50 generates an optotype (alignment optotype) for aligning the device optical system with respect to the eye E to be inspected. The focus optical system 60 generates an optotype (split optotype) for focusing on the eye E to be inspected.

The light (alignment light) output from the LED 51 of the alignment optical system 50 is reflected by the dichroic mirror 55 via the diaphragms 52 and 53 and the relay lens 54, and passes through the hole portion of the perforated mirror 21. The light that has passed through the hole of the perforated mirror 21 passes through the dichroic mirror 46 and is irradiated to the cornea of the eye E to be inspected by the objective lens 22.

The corneal reflected light of the alignment light passes through the objective lens 22, the dichroic mirror 46, and the above-mentioned hole portion, and a part thereof passes through the dichroic mirror 55 and passes through the photographing focusing lens 31. The corneal reflected light that has passed through the photographing focusing lens 31 is reflected by the mirror 32, transmitted through the half mirror 33A, reflected by the dichroic mirror 33, and projected onto the light receiving surface of the CCD image sensor 35 by the condenser lens 34. The light receiving image (alignment optotype) obtained by the CCD image sensor 35 is displayed on the display device 3 together with the observation image. The user performs the alignment by performing the same operation as the conventional fundus camera. Further, the arithmetic control unit 200 may analyze the position of the alignment optotype and move the optical system to perform alignment (auto alignment function).

The focus optical system 60 can move along the optical path of the illumination optical system 10 in conjunction with the movement of the photographing focusing lens 31 along the optical path of the photographing optical system 30. The reflection rod 67 of the focus optical system 60 is removable with respect to the illumination optical path.

When adjusting the focus, the reflecting surface of the reflecting rod 67 is obliquely provided on the illumination optical path. The light (focus light) output from the LED 61 of the focus optical system 60 passes through the relay lens 62, is separated into two luminous fluxes by the split optotype plate 63, and passes through the two-hole diaphragm 64. The light that has passed through the two-hole diaphragm 64 is reflected by the mirror 65, and is once imaged and reflected on the reflecting surface of the reflecting rod 67 by the condenser lens 66. Further, the focus light passes through the relay lens 20, is reflected by the perforated mirror 21, passes through the dichroic mirror 46, is refracted by the objective lens 22, and is irradiated to the fundus Ef.

The fundus reflected light of the focus light is detected by the CCD image sensor 35 through the same path as the corneal reflected light of the alignment light. The received light image (split visual image) by the CCD image sensor 35 is displayed on the display device 3 together with the observed image. The arithmetic control unit 200 analyzes the position of the split optotype image and moves the photographing focusing lens 31 and the focus optical system 60 to perform focusing (autofocus function), as in the conventional case. Further, the focus may be manually adjusted while visually recognizing the split optotype image.

The reflection rod 67 is inserted at a position on the illumination optical path that is optically coupled to the fundus Ef of the eye E to be inspected. The position of the reflecting surface of the reflecting rod 67 inserted in the optical path of the illumination optical system 10 is a position substantially coupled to the split visual reference plate 63. As described above, the split target luminous flux is separated into two by the action of the two-hole diaphragm 64 and the like. When the fundus Ef of the eye to be inspected E and the reflecting surface of the reflecting rod 67 are not conjugated, the split optotype image acquired by the CCD image sensor 35 is separated into two in the left-right direction and displayed on the display device 3, for example. Will be done. When the fundus Ef of the eye to be inspected E and the reflecting surface of the reflecting rod 67 are substantially coupled, the split optotype image acquired by the CCD image sensor 35 is displayed on the display device 3 in the vertical direction, for example. .. The focus optical system 60 is moved along the optical path of the illumination optical system 10 in conjunction with the photographing focusing lens 31 so that the fundus Ef and the split optotype plate 63 are always optically coupled. When the fundus Ef and the split optotype 63 are not conjugated, the split optotype is separated into two, so the focus optical system 60 is moved so that the two split optotypes coincide in the vertical direction. By doing so, the position of the photographing focusing lens 31 can be obtained. In this embodiment, the case where two split optotypes are acquired has been described, but three or more split optotypes may be used.

The dichroic mirror 46 branches the optical path for OCT from the optical path for fundus measurement. The dichroic mirror 46 reflects light in the wavelength band used for OCT and transmits light for measurement. The optical path for OCT is provided with a collimator lens unit 40, an optical path length changing unit 41, an optical scanner 42, an OCT focusing lens 43, a mirror 44, and a relay lens 45 in order from the OCT unit 100 side. Has been done.

The collimator lens unit 40 includes a collimator lens. The collimator lens unit 40 is optically connected to the OCT unit 100 by an optical fiber. The collimator lens of the collimator lens unit 40 is arranged at a position facing the emission end of the optical fiber. The collimator lens unit 40 converts the measurement light LS (described later) emitted from the emission end of the optical fiber into a parallel light beam, and collects the return light of the measurement light from the eye E to be examined to the emission end.

The optical path length changing unit 41 is movable in the direction of the arrow shown in FIG. 1, and changes the optical path length of the optical path for OCT. This change in the optical path length is used for correcting the optical path length according to the axial length of the eye E to be inspected, adjusting the interference state, and the like. The optical path length changing unit 41 includes, for example, a corner cube and a mechanism for moving the corner cube.

The optical scanner 42 is arranged at a position optically conjugate with the pupil of the eye E to be inspected. The optical scanner 42 changes the traveling direction of the light (measurement light LS) passing through the optical path for OCT. Thereby, the eye E to be inspected can be scanned by the measurement light LS. The optical scanner 42 includes, for example, a galvano mirror that scans the measurement light LS in the x direction, a galvano mirror that scans the measurement light LS in the y direction, and a mechanism that independently drives them. Thereby, the measurement light LS can be scanned in any direction on the xy plane.

The diaphragm 80 is inserted and removed from the measurement optical path, which is an optical path of parallel light between the collimator lens unit 40 and the optical scanner 42. The diaphragm 80 is a beam diameter changing member that changes the beam diameter of the measurement light LS by limiting the luminous flux of the measurement light LS. Such a diaphragm 80 is configured to include, for example, a flat member provided with a light flux passing region and a light flux blocking region provided around the light flux passing region. When the beam diameter is increased, the diaphragm 80 is retracted from the measurement optical path, and when the beam diameter is decreased, the diaphragm 80 is arranged in the measurement optical path. When the beam diameter is large, the SNR becomes large at the condensing position of the measurement light LS, so that a tomographic image is acquired in which the position corresponding to the condensing position is bright and the position corresponding to the position deviating from the condensing position is dark. On the other hand, when the beam diameter is small, the difference in SNR becomes small even at the condensing position of the measured light LS or at a position deviating from the condensing position, and a tomographic image that is uniformly bright to some extent is obtained at the corresponding positions. To be acquired. As a result, when it is determined that the brightness value of the tomographic image in the depth direction is small, it is possible to obtain a tomographic image that is more uniformly bright than before the beam diameter was changed by reducing the beam diameter of the measurement light. become.

Note that FIG. 1 shows a case where the beam diameter is changed by inserting and removing the diaphragm 80, but there are two or more light flux passing regions having different region sizes along the circumference about a predetermined rotation axis. A flat member which is formed and in which each light flux passing region can be selectively arranged in the measurement optical path may be provided. In this case, by rotating the plane member about the center of the rotation axis, it is possible to selectively change two or more arbitrary beam diameters for the measurement light LS.

[OCT unit]
An example of the configuration of the OCT unit 100 is shown in FIG. The OCT unit 100 is provided with an optical system for acquiring an OCT image of the eye E to be inspected. This optical system divides the light from the wavelength sweep type (wavelength scanning type) light source into the measurement light and the reference light, and causes the return light of the measurement light from the subject E to interfere with the reference light passing through the reference optical path. This is an interference optical system that generates interference light and detects this interference light. The detection result (detection signal) of the interference light by the interference optical system is an interference signal showing the spectrum of the interference light, and is sent to the arithmetic control unit 200.

The light source unit 101 is configured to include a wavelength sweep type (wavelength scanning type) light source capable of sweeping (scanning) the wavelength of emitted light, similarly to a general swept source type OCT device. The wavelength sweep type light source is configured to include a laser light source including a resonator. The light source unit 101 changes the output wavelength with time in a near-infrared wavelength band that cannot be visually recognized by the human eye. At least one of the wavelength sweep frequency (wavelength sweep speed) and the wavelength sweep width of the wavelength sweep type light source can be changed under the control of the control unit described later.

The light L0 output from the light source unit 101 is guided to the polarization controller 103 by the optical fiber 102, and its polarization state is adjusted. The polarization controller 103 adjusts the polarization state of the light L0 guided in the optical fiber 102 by, for example, applying stress from the outside to the looped optical fiber 102.

The light L0 whose polarization state is adjusted by the polarization controller 103 is guided by the optical fiber 104 to the fiber coupler 105 and divided into the measurement light LS and the reference light LR.

The reference light LR is guided to the collimator 111 by the optical fiber 110 and becomes a parallel light flux. The reference light LR that has become a parallel luminous flux is guided to the corner cube 114 via the optical path length correction member 112 and the dispersion compensation member 113. The optical path length correction member 112 acts as a delay means for matching the optical path length (optical distance) of the reference light LR with the optical path length of the measurement light LS. The dispersion compensating member 113 acts as a dispersion compensating means for matching the dispersion characteristics between the reference light LR and the measurement light LS.

The corner cube 114 turns back the traveling direction of the reference light LR, which has become a parallel luminous flux by the collimator 111, in the opposite direction. The optical path of the reference light LR incident on the corner cube 114 and the optical path of the reference light LR emitted from the corner cube 114 are parallel. Further, the corner cube 114 is movable in the direction along the incident optical path and the emitted optical path of the reference light LR. This movement changes the length of the optical path of the reference light LR.

In the configurations shown in FIGS. 1 and 2, the optical path length changing unit 41 for changing the length of the optical path (measurement optical path, measurement arm) of the measurement light LS and the optical path of the reference light LR (reference optical path, reference). Both corner cubes 114 for changing the length of the arm) are provided. However, only the corner cube 114 may be provided. Further, it is also possible to change the difference between the measured optical path length and the reference optical path length by using an optical member other than these.

The reference optical LR via the corner cube 114 is converted from a parallel luminous flux to a focused luminous flux by the collimator 116, incident on the optical fiber 117, and guided to the polarization controller 118 via the dispersion compensating member 113 and the optical path length correction member 112. Then, the polarization state of the reference light LR is adjusted.

The polarization controller 118 has, for example, the same configuration as the polarization controller 103. The reference light LR whose polarization state is adjusted by the polarization controller 118 is guided to the attenuator 120 by the optical fiber 119, and the amount of light is adjusted under the control of the arithmetic control unit 200. The reference optical LR whose light amount is adjusted by the attenuator 120 is guided to the fiber coupler 122 by the optical fiber 121.

On the other hand, the measurement light LS generated by the fiber coupler 105 is guided by the optical fiber 127 and is converted into a parallel luminous flux by the collimator lens unit 40. When the aperture 80 is retracted from the measurement optical path, the measurement light LS as a parallel light beam passes through the optical path length changing unit 41, the optical scanner 42, the OCT focusing lens 43, the mirror 44, and the relay lens 45, and is a dichroic mirror. Guided by 46. When the diaphragm 80 is arranged in the measurement optical path, the measurement light LS as a parallel light flux passes through the diaphragm 80, the optical path length changing unit 41, the optical scanner 42, the OCT focusing lens 43, the mirror 44, and the relay lens 45. It is guided to the dichroic mirror 46. The measurement light LS guided to the dichroic mirror 46 is reflected by the dichroic mirror 46, refracted by the objective lens 22, and irradiated to the eye E to be inspected. The measurement light LS is scattered (including reflection) at various depth positions of the eye E to be inspected. The return light of the measurement light LS including such backscattered light travels in the same path as the outward path in the opposite direction, is guided to the fiber coupler 105, and reaches the fiber coupler 122 via the optical fiber 128.

The fiber coupler 122 combines (interferes with) the measured light LS incident via the optical fiber 128 and the reference light LR incident via the optical fiber 121 to generate interference light. The fiber coupler 122 generates a pair of interference light LCs by branching the interference light between the measurement light LS and the reference light LR at a predetermined branching ratio (for example, 1: 1). The pair of interference light LCs emitted from the fiber coupler 122 are guided to the detector 125 by the optical fibers 123 and 124, respectively.

The detector 125 is, for example, a balanced photodiode (Balanced Photo Diode) that has a pair of photodetectors that detect each pair of interference light LCs and outputs the difference between the detection results. The detector 125 sends the detection result (interference signal) to the DAT (Data Acquisition System) 130. A clock KC is supplied to the DAQ 130 from the light source unit 101. The clock KC is generated in the light source unit 101 in synchronization with the output timing of each wavelength swept (scanned) by the wavelength sweep type light source within the set wavelength range (wavelength sweep width). The light source unit 101 optically delays one of the two branched lights obtained by branching the light L0 of each output wavelength, and then sets the clock KC based on the result of detecting these combined lights. Generate. The DAQ 130 samples the detection result of the detector 125 based on the clock KC. The DAQ 130 sends the detection result of the sampled detector 125 to the arithmetic control unit 200. The arithmetic control unit 200 obtains a reflection intensity profile in each A line by, for example, performing a Fourier transform or the like on the spectral distribution based on the detection result obtained by the detector 125 for each series of wavelength scans (for each A line). Form. Further, the arithmetic control unit 200 forms image data by imaging the reflection intensity profile of each A line.

[Operation control unit]
The configuration of the arithmetic control unit 200 will be described. The arithmetic control unit 200 analyzes the interference signal input from the detector 125 to form an OCT image of the eye to be inspected E, and calculates the intraocular distance of the eye to be inspected E. The arithmetic processing for forming the OCT image and the processing for calculating the intraocular distance are the same as those of the conventional swept source type ophthalmic apparatus.

Further, the arithmetic control unit 200 controls each part of the fundus camera unit 2, the display device 3, and the OCT unit 100. For example, the arithmetic control unit 200 causes the display device 3 to display the OCT image of the eye E to be inspected.

The arithmetic control unit 200 includes, for example, a microprocessor, a RAM (Random Access Memory), a ROM (Read Only Memory), a hard disk drive, a communication interface, and the like, as in a conventional computer. A computer program for controlling the ophthalmologic device 1 is stored in a storage device such as a hard disk drive. The arithmetic control unit 200 may include various circuit boards, for example, circuit boards for forming OCT images. Further, the arithmetic control unit 200 may include an operation device (input device) such as a keyboard and a mouse, and a display device such as an LCD.

[Control system]
The configuration of the control system (processing system) of the ophthalmic apparatus 1 will be described with reference to FIG. In addition, in FIG. 3, some components of the ophthalmic apparatus 1 are omitted, and components particularly necessary for explaining this embodiment are selectively shown.

(Control unit)
The arithmetic control unit 200 includes a control unit 210, an image forming unit 220, and a data processing unit 230. The control unit 210 includes, for example, a microprocessor, RAM, ROM, a hard disk drive, a communication interface, and the like. The control unit 210 is provided with a main control unit 211 and a storage unit 212.

(Main control unit)
The main control unit 211 performs the above-mentioned various controls. In particular, as shown in FIG. 3, the main control unit 211 controls the moving mechanism 31A, the insertion / removal mechanism 80A, the CCD image sensors 35 and 38, the LCD 39, the optical path length changing unit 41, and the optical scanner 42 of the fundus camera unit 2. do. Further, the main control unit 211 controls the light source unit 101 of the OCT unit 100, the moving mechanism 114A, the detector 125, the DAQ 130, and the like.

The ophthalmic appliance 1 can change the beam diameter of the measurement light LS incident on the eye E (or the objective lens 22) according to the scan data obtained by scanning the eye E to be inspected. The selection (designation) of the beam diameter may be performed by the main control unit 211, or may be performed by the user operating the operation unit 242 described later. When the beam diameter is selected by the main control unit 211, the same beam diameter as the previous one may be selected, or may be selected according to the measurement site of the subject or the eye to be inspected and the purpose of diagnosis.

The moving mechanism 31A moves the photographing focusing lens 31 along the optical axis of the photographing optical system 30. The moving mechanism 31A is provided with a holding member for holding the photographing focusing lens 31, an actuator for generating a driving force for moving the holding member, and a transmission mechanism for transmitting the driving force. The actuator is composed of, for example, a pulse motor. The transmission mechanism is composed of, for example, a combination of gears or a rack and pinion. As a result, the moving mechanism 31A controlled by the control unit 210 moves the photographing focusing lens 31, so that the focusing position of the photographing optical system 30 is changed. The moving mechanism 31A may move the photographing focusing lens 31 along the optical axis of the photographing optical system 30 manually or by operating the user's operation unit 242.

The insertion / removal mechanism 80A inserts / removes the aperture 80 with respect to the measurement optical path between the collimator lens unit 40 and the optical scanner 42. The insertion / removal mechanism 80A is provided with a holding member for holding the diaphragm 80, an actuator for generating a driving force for inserting / removing the holding member with respect to the measurement optical path, and a transmission mechanism for transmitting the driving force. .. As a result, the insertion / removal mechanism 80A controlled by the control unit 210 inserts / removes the diaphragm 80 with respect to the measurement optical path, so that the beam diameter of the measurement light LS is changed. It should be noted that the insertion / removal mechanism 80A may insert / remove the aperture 80 with respect to the measurement optical path by manual operation or operation with respect to the operation unit 242 of the user. As described above, when the diaphragm 80 includes a flat member having two or more light flux passing regions formed along the circumference about the rotation axis, a rotation mechanism is provided instead of the insertion / removal mechanism 80A. In this case, the rotation mechanism controlled by the control unit 210 is rotated around the rotation axis, so that two or more light flux passing areas are selectively arranged in the measurement optical path, so that the measurement light LS The beam diameter of is changed.

The main control unit 211 can control an optical system drive unit (not shown) to move the optical system provided in the ophthalmic apparatus 1 three-dimensionally. This control is used in alignment and tracking. Tracking is to move the device optical system according to the movement of the eye E to be inspected. When tracking is performed, alignment and focusing are performed in advance. Tracking maintains a suitable positional relationship in which alignment and focus are achieved by moving the device optical system in real time according to the position and orientation of the eye E to be inspected based on an image obtained by shooting a moving image of the eye E to be inspected. It is a function.

The moving mechanism 114A moves the corner cube 114 provided in the reference optical path. The moving mechanism 114A is provided with a holding member for holding the corner cube 114, an actuator for generating a driving force for moving the holding member, and a transmission mechanism for transmitting the driving force. Thereby, the length of the reference optical path is changed. The moving mechanism 114A may move the corner cube 114 along the reference optical path manually or by operating the user's operation unit 242.

(Memory)
The storage unit 212 stores various data. The data stored in the storage unit 212 includes, for example, the operation mode of the ophthalmic apparatus 1, the image data of the OCT image, the image data of the fundus image, the intraocular distance data of the eye to be inspected, the eye to be inspected information, and the like. The eye test information includes information about the subject such as the patient ID and name, and information about the test eye such as left eye / right eye identification information. Further, various programs and data for operating the ophthalmic apparatus 1 are stored in the storage unit 212.

(Image forming part)
The image forming unit 220 forms image data of a tomographic image of the eye E to be inspected such as the fundus Ef and the anterior eye portion based on the interference signal from the detector 125 (DAQ130). That is, the image forming unit 220 forms the image data of the eye E to be inspected based on the detection result of the interference light LC by the interference optical system. This process includes processing such as noise reduction (noise reduction), filter processing, and FFT (Fast Fourier Transform). The image data acquired in this way is a data set containing a group of image data formed by imaging a reflection intensity profile in a plurality of A lines (paths of each measured light LS in the eye E to be inspected). be.

In order to improve the image quality, it is possible to superimpose (add and average) a plurality of data sets collected by repeating scanning with the same pattern multiple times.

Further, the image forming unit 220 has two or more split optotype images from the image signal detected by the CCD 35 based on the return light of the two or more split optotypes from the eye E to be inspected that has passed through the photographing focusing lens 31. Form the depicted image. It should be noted that the formation of the image in which the two or more split optotypes are drawn may be performed by the main control unit 211.

The image forming unit 220 includes, for example, the circuit board described above. In this specification, "image data" and "image" based on the "image data" may be equated with each other. In addition, the site of the eye E to be inspected and the image thereof may be equated.

(Data processing unit)
The data processing unit 230 performs various data processing (image processing) and analysis processing on the image formed by the image forming unit 220. For example, the data processing unit 230 executes correction processing such as image brightness correction and dispersion correction. Further, the data processing unit 230 performs various image processing and analysis processing on the images (fundus image, anterior eye portion image, etc.) obtained by the fundus camera unit 2.

The data processing unit 230 can form volume data (voxel data) of the eye E to be inspected by executing known image processing such as interpolation processing for interpolating pixels between tomographic images. When displaying an image based on volume data, the data processing unit 230 performs rendering processing on the volume data to form a pseudo three-dimensional image when viewed from a specific line-of-sight direction.

The data processing unit 230 includes an evaluation unit 231 and an intraocular distance calculation unit 232.

The evaluation unit 231 evaluates the quality of the interference light LC by the interference optical system. The quality of the interference light LC corresponds to the SNR of the detection result (detection signal, detection data, interference signal) of the interference light LC and the image quality of the image formed by the image forming unit 220 based on the detection result. In this embodiment, the evaluation unit 231 evaluates the image quality of the tomographic image of the eye E to be inspected formed based on the detection result of the interference light LC. Specifically, the evaluation unit 231 evaluates the SNR (or contrast) in the depth direction in the acquired tomographic image of the eye E to be inspected. For example, the evaluation unit 231 obtains an evaluation value by integrating pixel values (luminance values) in the depth direction in the tomographic image.

Further, the evaluation unit 231 can evaluate the quality of the interference light LC obtained by scanning a designated area based on the operation content of the user with respect to the operation unit 242. In this case, the evaluation unit 231 evaluates the image quality of the tomographic image of the eye E to be inspected formed based on the detection result of the interference light LC generated by scanning the region.

The intraocular distance calculation unit 232 calculates the intraocular distance of one or more of the eye E to be inspected based on the detection data of two or more interference light LCs by the interference optical system. The intraocular distance calculation unit 232 calculates the intraocular distance of the eye E to be inspected based on the distance between the positions of the two interference signals based on the two interference lights included in the detection data. Such an intraocular distance calculation unit 232 can calculate the corneal thickness, the anterior chamber depth, the crystalline lens thickness, the axial length, and the like.

The data processing unit 230 can align the fundus image with the OCT image. When the fundus image and the OCT image are acquired in parallel, since both optical systems are coaxial, the fundus image and the OCT image acquired at (almost) simultaneously are taken as the optical axis of the photographing optical system 30. Can be aligned based on. Further, regardless of the acquisition timing of the fundus image and the OCT image, the alignment of the frontal image obtained by projecting at least a part of the image region corresponding to the fundus Ef on the xy plane of the OCT image and the fundus image is performed. By doing so, it is also possible to align the OCT image with the fundus image. This alignment method can be applied even when the optical system for acquiring a fundus image and the optical system for OCT are not coaxial. Even if both optical systems are not coaxial, if the relative positional relationship between the two optical systems is known, the same alignment as in the case of coaxial is executed with reference to this relative positional relationship. It is possible.

The data processing unit 230 that functions as described above includes, for example, a microprocessor, RAM, ROM, a hard disk drive, a circuit board, and the like. A computer program that causes a microprocessor to execute the above functions is stored in a storage device such as a hard disk drive in advance.

(User interface)
The user interface 240 includes a display unit 241 and an operation unit 242. The display unit 241 includes the display device and the display device 3 of the arithmetic control unit 200 described above. The operation unit 242 includes the operation device of the arithmetic control unit 200 described above. The operation unit 242 may include various buttons and keys provided on the housing of the ophthalmic appliance 1 or on the outside. Further, the display unit 241 may include various display devices such as a touch panel provided on the housing of the fundus camera unit 2.

The display unit 241 and the operation unit 242 do not need to be configured as separate devices. For example, it is also possible to use a device such as a touch panel in which a display function and an operation function are integrated. In that case, the operation unit 242 is configured to include the touch panel and a computer program. The operation content for the operation unit 242 is input to the control unit 210 as an electric signal. Further, the graphical user interface (GUI) displayed on the display unit 241 and the operation unit 242 may be used to perform operations and information input.

The optical system from the OCT unit 100 to the objective lens 22 via the optical scanner 42 is an example of the “data acquisition unit” according to the embodiment. The diaphragm 80 and the insertion / removal mechanism 80A are examples of the "beam size changing unit" according to the embodiment. The image forming unit 220 or the data processing unit 230 is an example of the “acquisition unit” according to the embodiment. The optical system included in the OCT unit 100 is an example of the “interference optical system” according to the embodiment. The operation unit 242 is an example of the "designated unit" according to the embodiment.

[Operation example]
The operation of the ophthalmic apparatus 1 according to the first embodiment will be described.

FIG. 4 shows an example of the operation of the ophthalmic apparatus 1 according to the first embodiment.

(S1)
First, the main control unit 211 controls the insertion / removal mechanism 80A to retract the diaphragm 80 from the measurement optical path. As a result, the beam diameter of the measurement light LS is set to the first beam diameter (initial beam diameter). The main control unit 211 projects an alignment optotype onto the eye to be inspected E by the alignment optical system 50 based on, for example, the user's operation with respect to the operation unit 242, and then controls the photographing optical system 30 in front of the eye to be inspected E. Acquire an anterior eye image in which the eye is depicted.

(S2)
Next, the main control unit 211 aligns the device optical system with respect to the eye E to be inspected by controlling an optical system drive unit (not shown) based on the anterior eye unit image acquired in S1 by a known method ( x direction, y direction and z direction).

(S3)
The main control unit 211 sets the optical scanner 42 at a predetermined initial position.

(S4)
The main control unit 211 turns on the light source unit 101 and controls the optical scanner 42 to start scanning the eye E to be inspected with the measurement light LS based on the light L0 from the light source unit 101. For example, the image forming unit 220 receives control from the main control unit 211, and is an OCT image (tomographic image) of the eye E (for example, fundus Ef) to be inspected based on the detection result of the interference light by the detector 125 as described above. To form.

(S5)
The main control unit 211 changes the focal position of the measurement light LS based on the detection signal of the interference light obtained by the detector 125. The main control unit 211 changes the focal position of the measurement light LS by controlling the moving mechanism 43D so that the amplitude of the detection signal of the predetermined interference light is maximized, for example.

(S6)
Subsequently, the main control unit 211 causes the evaluation unit 231 to evaluate the SNR in the depth direction of the detection signal corresponding to the detection result of the interference light LC detected by the detector 125 at the predetermined scanning position on the xy plane. For example, the main control unit 211 starts the OCT scan again using the measurement light LS whose focal position is changed in S5, and the tomographic image of the eye E to be inspected acquired or the tomographic image of the eye E to be inspected acquired in S4. The evaluation unit 231 calculates the evaluation value obtained by integrating the pixel values in the depth direction. The main control unit 211 changes the beam diameter of the measurement light LS based on the obtained evaluation value (that is, the scan data obtained by the OCT scan).

The main control unit 211 can control the beam diameter of the measured light LS to be smaller as the SNR of the detection result of the interference light LC is lower. For example, the main control unit 211 controls the beam size changing unit so that the beam diameter of the measurement light LS becomes the beam diameter D2 (first size) when the evaluation value is the first evaluation value corresponding to the first luminance. .. Further, when the evaluation value of the main control unit 211 is the second evaluation value corresponding to the second brightness lower than the first brightness, the beam diameter of the measurement light LS becomes the beam diameter D1 (D1 <D2, second size). The beam size change unit is controlled so as to.

Further, the main control unit 211 can change the beam diameter of the measurement light LS by controlling the insertion / removal mechanism 80A so that the obtained evaluation value (luminance in the first embodiment) is maximized. .. For example, the main control unit 211 repeats the acquisition of the tomographic image, the calculation of the evaluation value, the evaluation of the evaluation value, and the change of the beam diameter so that the beam diameter of the measured light LS is maximized. To change. When the beam diameter of the measurement light LS is the first beam diameter (initial beam diameter) and the evaluation value is the maximum, the beam diameter of the measurement light LS is not changed.

Further, the main control unit 211 can change the beam diameter of the measurement light LS by controlling the insertion / removal mechanism 80A so that the obtained evaluation value becomes equal to or higher than a predetermined target value. The target value may be a value that is determined and modifiable based on prior measurements.

(S7)
The main control unit 211 again controls the optical scanner 42 to start scanning the eye E to be inspected with the measurement light LS based on the light L0 from the light source unit 101. For example, the main control unit 211 causes the image forming unit 220 to form an OCT image of the eye E to be inspected based on the detection result of the interference light by the detector 125. Further, the main control unit 211 may have the intraocular distance calculation unit 232 calculate a predetermined intraocular distance in the fundus Ef or the anterior eye portion. For example, the main control unit 211 causes the intraocular distance calculation unit 232 to calculate at least one of the corneal thickness, the anterior chamber depth, the crystalline lens thickness, and the axial length based on the detection result of the interference light by the detector 125.

(S8)
Subsequently, the main control unit 211 determines whether or not to perform the next OCT measurement. The main control unit 211 can determine whether or not to perform the next OCT measurement based on the operation content of the user with respect to the operation unit 242. When it is determined that the next OCT measurement is to be performed (S8: N), the operation of the ophthalmic appliance 1 shifts to S1. When it is determined that the next OCT measurement is not performed (S8: Y), the operation of the ophthalmic appliance 1 ends (end).

Although FIG. 4 has described a case where the beam diameter of the measurement light LS is changed based on the evaluation result of one representative position in the OCT image, the configuration according to the embodiment is not limited to this. For example, the beam diameter of the measurement light LS is changed based on the evaluation result of the representative position of each of the two or more regions in which the OCT image is divided into at least one direction of the x direction, the y direction, and the z direction, and the beam is changed for each region. The OCT scan may be performed using the measurement light LS having a changed diameter. Further, for example, an evaluation value may be obtained for each scanning position on the xy plane, and the beam diameter of the measurement light LS may be changed for each scanning position.

As described above, according to the first embodiment, the beam diameter of the measured light LS (the diameter of the incident light flux to the eye to be inspected E or the objective lens 22) is determined according to the scan data of the eye to be inspected E acquired by the OCT scan. Can be changed. As a result, it becomes possible to improve the SNR regardless of the state of the subject or the measurement site of the eye to be inspected. For example, it is possible to obtain suitable measurement results regardless of the state of the fundus of the eye to be inspected E, the axial length of the eye to be inspected E, and whether or not the eye to be inspected E is a severe myopic eye. In particular, according to the first embodiment, since the luminous flux of the measurement light LS is changed based on the evaluation value obtained by integrating the brightness values of each pixel in the depth direction, it is uniform regardless of the condensing position of the measurement light LS. It is possible to obtain a tomographic image with high brightness.

In the first embodiment, the amount of light emitted by the wavelength sweep type light source may be controlled in association with the insertion / removal control of the diaphragm 80 with respect to the measurement optical path. For example, by increasing the amount of light when the diaphragm 80 is inserted into the measurement optical path and decreasing the amount of light when the diaphragm 80 is retracted from the measurement optical path, it is possible to improve the SNR while ensuring safety for the eye to be inspected. can.

<Second Embodiment>
In the first embodiment, the case where the beam diameter of the measurement light LS is changed by inserting and removing the diaphragm 80 with respect to the measurement optical path has been described, but the configuration of the ophthalmic apparatus according to the embodiment is not limited to this. do not have. For example, it is possible to change the beam diameter of the measurement light LS without limiting the luminous flux of the measurement light LS. Hereinafter, the ophthalmic apparatus according to the second embodiment will be described focusing on the differences from the first embodiment.

FIG. 5 shows an example of the configuration of the optical system of the ophthalmic apparatus according to the second embodiment. In FIG. 5, the same parts as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

The configuration of the optical system of the ophthalmic apparatus 1a according to the second embodiment is different from the configuration of the optical system of the ophthalmic apparatus 1 according to the first embodiment in that the aperture 80 is removed and the collimator lens unit 40 is replaced. This is the point where the varifocal lens 90 is provided. The varifocal lens 90 is a varifocal lens that changes the focal length (that is, the angle of view).

6A and 6B show a configuration example of the varifocal lens 90 of FIG. FIG. 6A shows a configuration example of the optical system of the varifocal lens 90 in a state where the beam diameter of the measurement light LS is set to the small beam diameter D1. FIG. 6B shows a configuration example of the optical system of the varifocal lens 90 in a state where the beam diameter of the measurement light LS is set to the large beam diameter D2. In FIGS. 6A and 6B, the same parts as those in FIG. 5 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

The varifocal lens 90 includes lenses 91, 92, 93. The lens 92 is movable in the optical axis direction. The lens 92 is moved in the optical axis direction by a moving mechanism (not shown). The lens 91 may be a meniscus lens. The lens 92 may be a plano-concave lens. The lens 93 may be a convex lens. The varifocal lens 90 is arranged at a position facing the emission end of the optical fiber 127. Specifically, the varifocal lens 90 is arranged so that its focal position coincides with the emission end of the optical fiber 127. The varifocal lens 90 converts the measurement light LS emitted from the emission end of the optical fiber 127 into a parallel light beam, and collects the return light of the measurement light from the eye E to be focused on the emission end.

When the beam diameter of the measurement light LS is reduced, the beam diameter D1 of the measurement light LS is set by moving the lens 92 toward the lens 91 (FIG. 6A). When increasing the beam diameter of the measurement light LS, the beam diameter D2 of the measurement light LS is set by moving the lens 92 toward the lens 93 (FIG. 6B).

FIG. 7 shows a block diagram of a configuration example of the control system of the ophthalmic apparatus 1a according to the second embodiment. In FIG. 7, the same parts as those in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

The difference between the control system of the ophthalmic apparatus 1a according to the second embodiment and the control system of the ophthalmic apparatus 1 according to the first embodiment is that the arithmetic control unit 200a is provided instead of the arithmetic control unit 200, and the insertion / removal is performed. This is a point in which control is performed on the moving mechanism 92A instead of the control on the mechanism 80A. The arithmetic control unit 200a includes a control unit 210a, an image forming unit 220, and a data processing unit 230. The difference between the control unit 210a and the control unit 210 is that the control unit 92A is controlled instead of the insertion / removal mechanism 80A. The control unit 210a includes a main control unit 211a and a storage unit 212a.

The moving mechanism 92A is provided with a holding member for holding the lens 92, an actuator for generating a driving force for moving the holding member, and a transmission mechanism for transmitting the driving force. Thereby, the optical distance between the lenses 91 and 92 and the optical distance between the lenses 92 and 93 are changed. The moving mechanism 92A may move the lens 92 in the optical axis direction manually or by operating the user's operation unit 242.

The operation of the ophthalmic apparatus 1a according to the second embodiment is substantially the same as the operation of the ophthalmic apparatus 1 according to the first embodiment shown in FIG. The ophthalmic apparatus 1a according to the second embodiment changes the beam diameter of the measured light LS to a smaller beam diameter by moving the lens 92 as shown in FIG. 6A in S3. Further, the ophthalmic apparatus 1a changes the beam diameter of the measured light LS to a large beam diameter by moving the lens 92 as shown in FIG. 6B in S5.

In the second embodiment, a zoom lens may be provided instead of the varifocal lens. Since the configuration of the zoom lens is known, detailed description thereof will be omitted. In this case, the control unit 210a can change the beam diameter of the measurement light LS by controlling the zoom lens.

As described above, according to the second embodiment, the beam diameter of the measured light LS is changed by controlling the varifocal lens according to the scan data of the eye E to be inspected, so that the amount of light is reduced. It becomes possible to obtain a suitable OCT measurement result.

[effect]
The effect of the ophthalmic apparatus according to the embodiment will be described.

The ophthalmic apparatus (1, 1a) according to the embodiment includes a data collecting unit (an optical system from the OCT unit 100 to the objective lens 22 via the optical scanner 42) and a beam size changing unit (aperture 80 and insertion / removal). The mechanism 80A) and an acquisition unit (image forming unit 220 or data processing unit 230) are included. The data collection unit collects data by scanning the eye to be inspected (E) using a light beam (measurement light LS). The beam size changing unit changes the size of the light beam (beam diameter, light flux diameter, incident light flux diameter, diameter in the direction orthogonal to the optical axis of the optical system). The acquisition unit acquires data related to the eye to be inspected (measurement results such as an image of the eye to be inspected and an intraocular distance) based on the data collected by the data acquisition unit using an optical beam whose size has been changed by changing the beam size. ..

With such a configuration, the size of the light beam can be changed, data is collected by scanning the eye to be inspected with the changed light beam, and data on the eye to be inspected is acquired. Compared with the case where the diameter is fixed, the SNR of the scan result can be improved and a suitable measurement result can be obtained.

Further, the ophthalmic apparatus according to the embodiment may include a control unit (210, main control unit 211) that controls the beam size changing unit based on the data collected by the data collection unit.

With such a configuration, it is possible to improve the SNR of the scan result regardless of the state of the eye to be inspected.

Further, in the ophthalmic apparatus according to the embodiment, the acquisition unit includes an image forming unit (220) that forms an image of the eye to be inspected based on the above data, and evaluates the image quality of the image formed by the image forming unit. The control unit may control the beam size change unit based on the evaluation result by the evaluation unit, including the unit (231).

According to such a configuration, an image of the eye to be inspected is formed based on the data obtained by scanning the eye to be inspected using the light beam, and the beam diameter of the light beam is based on the evaluation result of the formed image. Therefore, it is possible to acquire a high-definition image of the eye to be inspected regardless of the state of the eye to be inspected.

Further, in the ophthalmic apparatus according to the embodiment, the acquisition unit acquires a tomographic image of the eye to be inspected based on the data collected by using optical coherence stromography, and the evaluation unit acquires an evaluation value corresponding to the brightness of the tomographic image. The control unit may control the beam size change unit so that the brightness of the tomographic image is maximized based on the evaluation value calculated by the evaluation unit.

With such a configuration, it becomes possible to acquire a high-definition tomographic image of the eye to be inspected whose brightness is optimized regardless of the state of the eye to be inspected.

Further, in the ophthalmic apparatus according to the embodiment, the evaluation unit may calculate the evaluation value based on the pixel value in the depth direction of the light beam in the tomographic image.

With such a configuration, it becomes possible to acquire a tomographic image of the eye to be inspected whose brightness in the depth direction of the light beam is optimized regardless of the state of the eye to be inspected.

Further, in the ophthalmic apparatus according to the embodiment, the control unit controls the beam size changing unit so that the size of the light beam becomes the first size (D2) when the evaluation value is the first evaluation value corresponding to the first luminance. Then, when the evaluation value is the second evaluation value corresponding to the second brightness lower than the first brightness, the beam size change unit is controlled so that the size of the light beam becomes the second size (D1) smaller than the first size. May be good.

According to such a configuration, the lower the brightness, the smaller the beam size of the light beam for collecting data is controlled. Therefore, even if the brightness is uneven, the eye to be inspected has a certain degree of unevenness. It is possible to obtain a high-quality image with uniform brightness.

Further, the ophthalmic apparatus according to the embodiment is arranged in the optical path of the light beam, and has a focusing lens (OCT focusing lens 43) that can move along the optical path and a movement that moves the focusing lens along the optical path. The control unit can control the beam size change unit after changing the focal position of the optical beam to a predetermined position by controlling the movement mechanism, including the mechanism (43A).

According to such a configuration, since the beam diameter is changed after adjusting the focus of the light beam, it is possible to evaluate the depth direction of the light beam with high accuracy, and it is possible to obtain suitable measurement results. It will be possible.

Further, the ophthalmic appliance according to the embodiment has a designated unit (operation unit 242) for designating the size of the light beam and a control unit (control unit 210) for controlling the beam size changing unit so as to have the size specified by the designated unit. , Main control unit 211), and may be included.

According to such a configuration, it is possible to obtain a suitable measurement result regardless of the state of the eye to be inspected by changing the light beam to the size designated by the designated unit.

Further, in the ophthalmic apparatus according to the embodiment, the beam size changing unit may include a diaphragm (80) and an insertion / removal mechanism (80A) for inserting and removing the diaphragm with respect to the optical path (measurement optical path) of the light beam. ..

According to such a configuration, the size of the light beam is changed by inserting and removing the diaphragm with respect to the optical path of the light beam, so that the size of the light beam can be changed with a simple configuration. ..

Further, in the ophthalmic apparatus according to the embodiment, the data collection unit divides the light (L0) from the light source (wavelength sweep type light source) into the measurement light (LS) and the reference light (LR), and divides the measurement light into an optical beam. The interference optical system (optical system included in the OCT unit 100) that is incident on the eye to be inspected and detects the interference light (LC) between the return light of the measurement light from the eye to be inspected and the reference light, and the measurement light is converted into a parallel light beam. The collimator lens (collimeter lens unit 40) and the optical scanner (42) that deflects the measurement light converted into parallel light by the collimeter lens are included, and the insertion / removal mechanism is the measurement light between the collimeter lens and the optical scanner. The aperture may be inserted or removed from the optical path of.

According to such a configuration, the diaphragm is inserted and removed from the optical path of the measurement light as a parallel luminous flux, so that the beam size of the measurement light can be changed with a simple configuration and simple control. It will be possible.

Further, in the ophthalmic apparatus according to the embodiment, the beam size changing unit includes a varifocal lens (90) or a zoom lens arranged in the optical path of the light beam, and the control unit controls the varifocal lens or the zoom lens. May be good.

According to such a configuration, since the size of the light beam is changed by using a varifocal lens or a zoom lens, it is possible to change the size of the light beam without causing a decrease in the amount of light from the light source. It will be possible.

Further, in the ophthalmic apparatus according to the embodiment, the data collection unit divides the light (L0) from the light source (wavelength sweep type light source) into the measurement light (LS) and the reference light (LR), and divides the measurement light into an optical beam. An interference optical system (optical system included in the OCT unit 100) that detects the interference light between the return light of the measurement light from the test eye and the reference light, and an optical scanner (42) that deflects the measurement light. ), And the varifocal lens or zoom lens may be located between the light source and the optical scanner.

According to such a configuration, the beam size of the measurement light as a parallel luminous flux is changed by using a varifocal lens or a zoom lens, so that the beam size of the measurement light can be changed with a simple configuration and simple control. Can be changed.

<Modification example>
The embodiments shown above are merely examples for carrying out the present invention. A person who intends to carry out the present invention can make arbitrary modifications, omissions, additions, etc. within the scope of the gist of the present invention.

In the above-described embodiment or a modification thereof, the case where the configuration of the optical system in the ophthalmic apparatus according to the embodiment is the configuration shown in FIGS. 1 and 2 has been described, but the configuration of the optical system is not limited to this. The optical system according to the embodiment may include an optical system for irradiating a treatment site on the fundus with a laser beam, an optical system for moving an optotype while the eye to be examined is fixed, and the like.

1, 1a Ophthalmology device 40 Collimeter lens unit 42 Optical scanner 80 Aperture 80A Insertion / removal mechanism 90 Varifocal lens 92A Movement mechanism 100 OCT unit 200, 200a Arithmetic control unit 210, 210a Control unit 211, 211a Main control unit 230 Data processing unit 231 Evaluation unit 232 Intraocular distance calculation unit 220 Image formation unit 242 Operation unit E Eye to be inspected LC Interference light LR Reference light LS Measurement light

Claims (8)

An ophthalmic device that acquires data on the eye to be inspected by swept source OCT.
A data acquisition unit that collects data by scanning the eye to be inspected using a light beam as measurement light generated based on the light from a wavelength sweep type light source.
A beam size changing unit that changes the size of the light beam,
An acquisition unit that acquires a tomographic image of the eye to be inspected based on the data collected by the data acquisition unit using the light beam whose size has been changed due to the beam size change.
An evaluation unit that calculates an evaluation value by integrating pixel values in the depth direction of the tomographic image, and an evaluation unit.
A control unit that controls the beam size changing unit so that the smaller the evaluation value is, the smaller the beam diameter of the light beam is.
Ophthalmic equipment including. The ophthalmic apparatus according to claim 1, wherein the control unit controls the amount of light from the wavelength sweep type light source in cooperation with the control of changing the size of the light beam by the beam size changing unit. The control unit controls the beam size changing unit so that the size of the light beam becomes the first size when the evaluation value is the first evaluation value corresponding to the first luminance, and the evaluation value is the first. Claim 1 is characterized in that the beam size changing unit is controlled so that the size of the light beam becomes a second size smaller than the first size when the second evaluation value corresponds to the second brightness lower than the brightness. Or the ophthalmic apparatus according to claim 2 . A focusing lens arranged in the optical path of the optical beam and movable along the optical path,
A moving mechanism that moves the focusing lens along the optical path,
Including
The control unit according to claim 1 to 3 , wherein the control unit controls the beam size change unit after changing the focal position of the light beam to a predetermined position by controlling the movement mechanism. The ophthalmic apparatus according to any one of the following items. The beam size changing part is
Aperture and
An insertion / removal mechanism for inserting / removing the diaphragm with respect to the optical path of the light beam,
The ophthalmic apparatus according to any one of claims 1 to 4, wherein the ophthalmic apparatus comprises. The data collection unit
The light from the light source is divided into a measurement light and a reference light, the measurement light is incident on the test eye as the light beam, and the return light of the measurement light from the test eye and the interference light between the reference light are detected. Interfering optical system and
A collimator lens that converts the measured light into a parallel luminous flux,
An optical scanner that deflects the measured light, which is a parallel luminous flux by the collimator lens,
Including
The ophthalmic apparatus according to claim 5, wherein the insertion / removal mechanism inserts / removes the diaphragm with respect to the optical path of the measurement light between the collimator lens and the optical scanner. The beam resizing unit includes a varifocal lens or a zoom lens arranged in the optical path of the light beam.
The ophthalmic apparatus according to any one of claims 1 to 6 , wherein the control unit controls the varifocal lens or the zoom lens. The data collection unit
The light from the light source is divided into a measurement light and a reference light, the measurement light is incident on the test eye as the light beam, and the return light of the measurement light from the test eye and the interference light between the reference light are detected. Interfering optical system and
An optical scanner that deflects the measurement light,
Including
The ophthalmic apparatus according to claim 7, wherein the varifocal lens or the zoom lens is arranged between the light source and the optical scanner.

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