JP2020039560A - Ophthalmologic apparatus and control method thereof - Google Patents

Abstract

To provide an ophthalmologic apparatus capable of preventing deterioration in detection sensitivity of OCTA even when a measuring speed is increased, and a control method thereof.SOLUTION: An ophthalmologic apparatus includes: an OCT measuring unit for repeatedly executing OCT measurement to the same site of an eye to be examined at a changeable measuring speed; a first data generation unit for generating first motion contrast data on the basis of a plurality of measurement results acquired by repeating the OCT measurement at a first measuring speed by the OCT measuring unit to a first measurement site of the eye to be examined; a site designation unit for designating a second measurement site of the eye to be examined on the basis of the first motion contrast data; and a second data generation unit for generating second motion contrast data on the basis of a plurality of measurement results acquired by repeating the OCT measurement at a second measuring speed by the OCT measuring unit to a second measurement site designated by the site designation unit.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an ophthalmologic apparatus and a control method thereof.

  2. Description of the Related Art In recent years, optical coherence tomography (OCT), which measures and forms an image of an object to be measured using a light beam from a laser light source or the like, has attracted attention. Since OCT does not have invasiveness to a human body like X-ray CT (Computed Tomography), it is expected to be applied particularly in the medical field and the biological field. For example, in the field of ophthalmology, apparatuses for forming images of the fundus, the cornea, and the like have been put to practical use. An apparatus using such OCT (OCT apparatus) can be applied to measurement and observation of various parts (fundus and anterior segment) of the eye to be examined. Further, since high-definition images can be obtained, they are applied to diagnosis of various ophthalmic diseases.

  When performing OCT measurement on an eye to be examined, it is desired to increase the measurement speed (A-scan speed) in order to reduce the effects of fixation disparity and the like. Increasing the measurement speed of OCT measurement is effective for obtaining a highly accurate OCT measurement result.

  On the other hand, there has been proposed a method of drawing a blood flow using OCT without using a contrast agent. This technique is called OCT Angiography (OCTA). In OCTA, a change in intensity or a change in phase between measurement results obtained by repeatedly performing OCT measurement on the same part of the subject's eye (for example, the fundus) is detected. For example, Patent Literature 1 and Non-Patent Literature 1 disclose a method of acquiring an angiographic image in which the position of a blood vessel is depicted using OCTA.

JP-A-2015-131107

Anqi Zhang et al. , "Methods and algorithms for optical coherence tomography-based angiography: a review and comprison", Journal of Biomedical, October 15, United States, October 20, United States. 20 (10), pp. 100901-1 to 100901-13

  However, increasing the measurement speed (A-scan speed) lowers the sensitivity of the detected interference signal, and makes it difficult to obtain highly accurate OCT measurement results. In particular, in OCTA, the time interval of OCT measurement performed on the same site is shortened, and the intensity change between measurement results and the like are reduced. Therefore, it is conceivable that the detection sensitivity for a slow blood flow is reduced.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an ophthalmologic apparatus capable of preventing a decrease in OCTA detection sensitivity even when the measurement speed is improved, and a control method thereof. Is to do.

  A first aspect of some embodiments is an OCT measurement unit that repeatedly performs OCT measurement on the same part of the subject's eye at a changeable measurement speed, and the OCT measurement on a first measurement part of the subject's eye. A first data generation unit that generates first motion contrast data based on a plurality of measurement results obtained by repeating OCT measurement at a first measurement speed by the unit; and the subject's eye based on the first motion contrast data. And a OCT measurement unit that repeats OCT measurement at a second measurement speed by the OCT measurement unit for the second measurement site specified by the site specification unit. A second data generation unit that generates second motion contrast data based on a plurality of measurement results.

  According to a second aspect of some embodiments, in the first aspect, an operation unit is included, and the site specification unit specifies a site specified using the operation unit as the second measurement site.

  A third aspect of some embodiments includes, in the first aspect, an analysis unit that specifies a site to be re-measured by analyzing a front image of the eye to be inspected, and the site designation unit includes: The specified part is designated as the second measurement part.

  A fourth aspect of some embodiments is the first aspect, wherein the first motion contrast data includes an analysis unit that specifies a site to be re-measured by analyzing the first motion contrast data, and the site designation unit includes The specified part is designated as the second measurement part.

  A fifth aspect of some embodiments is the fourth aspect, further comprising an OCTA image forming unit that forms a first OCTA image based on the first motion contrast data, wherein the analyzing unit includes a spatial frequency in the first OCTA image. Is specified as a region to be re-measured.

  According to a sixth aspect of some embodiments, in the fifth aspect, the OCTA image forming unit forms an intensity image based on amplitude information of the first motion contrast data, and forms a phase image of the first motion contrast data. A phase image is formed based on the information, and the analysis unit specifies the part to be re-measured based on the intensity image and the phase image.

  According to a seventh aspect of some embodiments, in any one of the first to fourth aspects, a first OCTA image is formed based on the first motion contrast data, and a second OCTA image is formed based on the second motion contrast data. An OCTA image forming unit that forms an image, and a display control unit that displays the first OCTA image and the second OCTA image on the same screen of a display unit.

  In an eighth aspect of some embodiments, according to any one of the first to seventh aspects, the OCT measurement unit converts light from a wavelength-swept light source whose wavelength sweep speed can be changed into measurement light and reference light. Dividing, irradiating the eye to be measured with the measurement light, including an interference optical system for detecting interference light between the return light of the measurement light from the eye to be examined and the reference light, and changing the wavelength sweep speed. And a control unit for changing the measurement speed of the OCT measurement.

  In a ninth aspect of some embodiments, in any of the first to eighth aspects, the second measurement site is a part of the first measurement site.

  In a tenth aspect of some embodiments, in any one of the first to ninth aspects, the second measurement speed is lower than the first measurement speed.

  An eleventh aspect of some embodiments includes a first measurement step of repeatedly performing OCT measurement at a first measurement speed on a first measurement site of an eye to be inspected, and a plurality of measurements acquired in the first measurement step. A first data generation step of generating first motion contrast data based on a result, and a second measurement site of the subject's eye based on the first motion contrast data generated in the first data generation step. A part designation step, a second measurement step of repeatedly performing OCT measurement at a second measurement speed on the second measurement part designated in the part designation step, and a plurality of Generating a second motion contrast data based on the measurement result. A control method of the apparatus.

  In a twelfth aspect of some embodiments, in the eleventh aspect, the part designation step designates a part designated using an operation unit as the second measurement part.

  A thirteenth aspect of some embodiments according to the eleventh aspect, includes an analysis step of identifying a part to be re-measured by analyzing a front image of the eye to be inspected, wherein the part designation step is performed in the analysis step. The specified part is designated as the second measurement part.

  A fourteenth aspect of some embodiments according to the eleventh aspect includes an analysis step of identifying a part to be re-measured by analyzing the first motion contrast data, wherein the part designation step is performed in the analysis step. The specified part is designated as the second measurement part.

  A fifteenth aspect of some embodiments according to the fourteenth aspect, further comprising an OCTA image forming step of forming a first OCTA image based on the first motion contrast data, wherein the analyzing step includes a step of generating a spatial frequency in the first OCTA image. Is specified as a region to be re-measured.

  In a sixteenth aspect of some embodiments, in the fifteenth aspect, the OCTA image forming step forms an intensity image based on amplitude information of the first motion contrast data, and forms a phase of the first motion contrast data. A phase image is formed based on the information, and the analyzing step specifies the portion to be re-measured based on the intensity image and the phase image.

  A seventeenth aspect of some embodiments is a method according to any of the eleventh to fourteenth aspects, wherein a first OCTA image is formed based on the first motion contrast data, and a second OCTA image is formed based on the second motion contrast data. An OCTA image forming step of forming an image; and a display control step of displaying the first OCTA image and the second OCTA image on the same screen of a display unit.

  In an eighteenth aspect of some embodiments, in any one of the eleventh aspect to the seventeenth aspect, the first measurement step and the second measurement step include light from a wavelength sweep light source whose wavelength sweep speed can be changed. Dividing into measurement light and reference light, irradiating the eye to be examined with the measurement light, detecting return light of the measurement light from the eye to be examined and interference light with the reference light, the second measurement step The measurement speed of the OCT measurement is changed by changing the wavelength sweep speed.

  According to the present invention, it is possible to provide an ophthalmologic apparatus capable of preventing a decrease in OCTA detection sensitivity even when the measurement speed is improved, and a control method thereof.

FIG. 2 is a schematic diagram illustrating an example of a configuration of an ophthalmologic apparatus according to an embodiment. FIG. 2 is a schematic diagram illustrating an example of a configuration of an ophthalmologic apparatus according to an embodiment. FIG. 2 is a schematic diagram illustrating an example of a configuration of an ophthalmologic apparatus according to an embodiment. FIG. 2 is a schematic block diagram illustrating an example of a configuration of an ophthalmologic apparatus according to an embodiment. FIG. 2 is a schematic block diagram illustrating an example of a configuration of an ophthalmologic apparatus according to an embodiment. 6 is a flowchart illustrating an operation example of the ophthalmologic apparatus according to the embodiment. It is a schematic diagram for explaining processing which an ophthalmologic apparatus concerning an embodiment performs. 6 is a flowchart illustrating an operation example of the ophthalmologic apparatus according to the embodiment.

  An embodiment of an ophthalmologic apparatus and a method of controlling the ophthalmic apparatus according to the present invention will be described in detail with reference to the drawings. In addition, the description content of the literature and any known technology cited in this specification can be used in the following embodiments.

  In this specification, an image acquired by OCT may be collectively referred to as an OCT image. Further, a measurement operation for forming an OCT image may be referred to as OCT measurement.

  The ophthalmologic apparatus according to the embodiment obtains a plurality of OCT measurement results by repeatedly performing OCT measurement on substantially the same part of the subject's eye, and generates motion contrast data from the obtained plurality of OCT measurement results. Is possible.

  Further, the ophthalmologic apparatus according to the embodiment can change the measurement speed (A scan speed) in the OCT measurement. The ophthalmic apparatus specifies a remeasurement site in the eye to be inspected based on the motion contrast data generated by repeatedly performing the OCT measurement at the first measurement speed, and performs the second measurement speed with respect to the specified remeasurement site. New motion contrast data can be generated by repeatedly executing the OCT measurement. This makes it possible to detect, by the OCT measurement at the second measurement speed, a change in intensity or the like that could not be detected by the OCT measurement at the first measurement speed.

  An ophthalmologic apparatus according to some embodiments includes at least one of an ophthalmologic photographing apparatus, an ophthalmologic measuring apparatus, and an ophthalmic treatment apparatus. The ophthalmologic imaging apparatus included in the ophthalmologic apparatus according to some embodiments is, for example, any one or more of a fundus camera, a scanning laser ophthalmoscope, a slit lamp ophthalmoscope, a surgical microscope, and the like. Further, the ophthalmologic measurement apparatus included in the ophthalmologic apparatus according to some embodiments includes, for example, any one or more of an eye refraction test apparatus, a tonometer, a specular microscope, a wavefront analyzer, a perimeter, a microperimeter, and the like. It is. In addition, the ophthalmic treatment device included in the ophthalmologic device of some embodiments is, for example, one or more of a laser treatment device, a surgical device, a surgical microscope, and the like.

  An ophthalmologic apparatus according to the following embodiments includes an OCT apparatus capable of OCT measurement and a fundus camera. Further, the configuration according to the following embodiment can be incorporated in a single OCT device. In the following, an ophthalmologic apparatus including an OCT apparatus to which swept source OCT is applied will be described. However, the type of OCT is not limited to this, and other types of OCT (spectral domain OCT, time domain OCT, amphas OCT, etc.) may be used. May be applied.

  Hereinafter, an ophthalmologic apparatus capable of performing OCT measurement on the fundus will be mainly described. However, the following embodiments can be applied to an ophthalmologic apparatus that can perform OCT measurement on the anterior eye. In some embodiments, the OCT measurement range and the measurement site are changed by moving a lens that changes the focal position of the measurement light. In some embodiments, the addition of one or more attachments (objective lens, anterior lens, etc.) provides OCT measurement for the fundus, OCT measurement for the anterior segment, and OCT measurement for the whole eye including the fundus and the anterior segment. It has a configuration that allows measurement. In some embodiments, in an ophthalmologic apparatus for fundus measurement, the anterior ocular segment may be configured such that the measurement light converted into a parallel light beam is incident on the subject's eye by disposing a head lens between the objective lens and the subject's eye. OCT measurement is performed.

<Structure>
〔Optical system〕
As shown in FIG. 1, the ophthalmologic apparatus 1 includes a fundus camera unit 2, an OCT unit 100, and an arithmetic and control unit 200. The retinal camera unit 2 is provided with an optical system and a mechanism for acquiring a front image of the eye E to be inspected. The OCT unit 100 is provided with a part of an optical system and a mechanism for performing the OCT. Another part of the optical system and the mechanism for performing the OCT is provided in the fundus camera unit 2. The arithmetic and control unit 200 includes one or more processors that execute various calculations and controls. In addition to these, arbitrary elements such as a member for supporting the subject's face (chin rest, forehead support, etc.) and a lens unit for switching the target site of OCT (for example, an anterior segment OCT attachment) And a unit may be provided in the ophthalmologic apparatus 1. In some embodiments, the lens unit is configured to be manually inserted and removed between the subject's eye E and an objective lens 22 described later. In some embodiments, the lens unit is configured to be automatically inserted and removed between the subject's eye E and the objective lens 22 described below under the control of the control unit 210 described below.

  In this specification, a “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, an SPLD (Simple Graphical Programmable Programmable Programmable Logic), or a programmable logic device (for example, an SPLD (Simple Programmable Programmable Programmable Logic Programmable Programmable Logic)). It means a circuit such as a programmable logic device (FPGA) or a field programmable gate array (FPGA). The processor realizes the functions according to the embodiment by, for example, reading and executing a program stored in a storage circuit or a storage device.

[Fundus camera unit]
The retinal camera unit 2 is provided with an optical system for photographing the fundus oculi Ef of the eye E. The acquired image of the fundus oculi Ef (referred to as a fundus image, a fundus photograph, or the like) is a front image such as an observation image or a photographed image. The observation image is obtained by moving image shooting using near-infrared light. The photographed image is a still image using flash light. Further, the fundus camera unit 2 can photograph the anterior segment Ea of the eye E to acquire a front image (anterior segment image).

  The retinal camera unit 2 includes an illumination optical system 10 and a photographing optical system 30. The illumination optical system 10 irradiates the eye E with illumination light. The imaging optical system 30 detects the return light of the illumination light from the eye E to be inspected. The measurement light from the OCT unit 100 is guided to the eye E through an optical path in the fundus camera unit 2, and the return light is guided to the OCT unit 100 through the same optical path.

  Light (observation illumination light) output from the observation light source 11 of the illumination optical system 10 is reflected by a reflection mirror 12 having a curved reflection surface, passes through a condenser lens 13, and passes through a visible cut filter 14. It becomes near infrared light. Further, the observation illumination light is once focused near the imaging light source 15, reflected by the mirror 16, and passes through the relay lenses 17 and 18, the diaphragm 19 and the relay lens 20. Then, the observation illumination light is reflected at the periphery of the apertured mirror 21 (the area around the aperture), passes through the dichroic mirror 46, is refracted by the objective lens 22, and is refracted by the eye E (the fundus Ef or the anterior eye) The part Ea) is illuminated. The return light of the observation illumination light from the eye E 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, and passes through the dichroic mirror 55. . The return light transmitted through the dichroic mirror 55 passes through the imaging focusing lens 31, and is reflected by the mirror 32. Further, this return light passes through the half mirror 33A, is reflected by the dichroic mirror 33, and forms an image on the light receiving surface of the image sensor 35 by the condenser lens. The image sensor 35 detects return light at a predetermined frame rate. Note that the focus of the imaging optical system 30 is adjusted so as to match the fundus oculi Ef or the anterior ocular segment Ea.

  Light (photographing illumination light) output from the photographing light source 15 is applied to the fundus oculi Ef through the same path as the observation illumination light. The return light of the imaging illumination light from the eye E is guided to the dichroic mirror 33 through the same path as the return light 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. An image is formed on the light receiving surface of the image sensor 38.

  An LCD (Liquid Crystal Display) 39 displays a fixation target and a visual acuity measurement target. A part of the light beam output from the LCD 39 is reflected by the half mirror 33A, reflected by the mirror 32, passes through the imaging focusing lens 31 and the dichroic mirror 55, and passes through the hole of the perforated mirror 21. The light beam 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 projected on the fundus Ef.

  By changing the display position of the fixation target on the screen of the LCD 39, the fixation position of the eye E can be changed. As an example of the fixation position, a fixation position for acquiring an image centered on the macula, a fixation position for acquiring an image centered on the optic disc, and a fundus center between the macula and the optic disc. There is a fixation position for acquiring an image centered on, and a fixation position for acquiring an image of a part (peripheral part of the fundus) far away from the macula. The ophthalmologic apparatus 1 according to some embodiments includes a GUI (Graphical User Interface) for specifying at least one of such fixation positions. The ophthalmologic apparatus 1 according to some embodiments includes a GUI or the like for manually moving a fixation position (a display position of a fixation target).

  The configuration for presenting the movable fixation target to the eye E is not limited to a display device such as an LCD. For example, a movable fixation target can be generated by selectively lighting a plurality of light sources in a light source array (such as a light emitting diode (LED) array). In addition, a movable fixation target can be generated by one or more movable light sources.

  Further, the ophthalmologic apparatus 1 may be provided with one or more external fixation light sources. One of the one or more external fixation light sources is capable of projecting fixation light to a concomitant eye of the eye E to be inspected. The projection position of the fixation light in the concomitant eye can be changed. The fixation position of the eye E can be changed by changing the projection position of the fixation light on the contributing eye. The fixation position by the external fixation light source may be the same as the fixation position of the subject's eye E using the LCD 39. For example, a movable fixation target can be generated by selectively lighting a plurality of external fixation light sources. In addition, a movable fixation target can be generated by one or more movable external fixation light sources.

  The alignment optical system 50 generates an alignment index used for alignment of the optical system with the eye E. The alignment light output from the LED 51 passes through the apertures 52 and 53 and the relay lens 54, is reflected by the dichroic mirror 55, and passes through the hole 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 projected onto the eye E by the objective lens 22. The corneal reflected light of the alignment light is guided to the image sensor 35 through the same path as the return light of the observation illumination light. Manual alignment or automatic alignment can be performed based on the received light image (alignment index image).

  The focus optical system 60 generates a split index used for focus adjustment on the eye E. The focus optical system 60 is moved along the optical path (illumination optical path) of the illumination optical system 10 in conjunction with the movement of the imaging focusing lens 31 along the optical path (illumination optical path) of the imaging optical system 30. The reflection bar 67 is insertable into and removable from the illumination optical path. When performing the focus adjustment, the reflection surface of the reflection bar 67 is arranged obliquely in the illumination optical path. Focus light output from the LED 61 passes through a relay lens 62, is split into two light beams by a split indicator plate 63, passes through a two-hole aperture 64, is reflected by a mirror 65, and is reflected by a condensing lens 66 on a reflecting rod 67. Is once imaged on the reflecting surface of and is reflected. Further, the focus light passes through the relay lens 20, is reflected by the aperture mirror 21, passes through the dichroic mirror 46, is refracted by the objective lens 22, and is projected on the fundus Ef. The fundus reflection light of the focus light is guided to the image sensor 35 through the same path as the corneal reflection light of the alignment light. Manual focus or auto focus can be executed based on the received light image (split index image).

  The dichroic mirror 46 combines the optical path for fundus imaging and the optical path for OCT. The dichroic mirror 46 reflects light in a wavelength band used for OCT and transmits light for fundus imaging. The OCT optical path (the optical path of the measurement light) includes a collimator lens unit 40, an optical path length changing unit 41, an optical scanner 42, an OCT focusing lens 43, a mirror 44, in order from the OCT unit 100 side to the dichroic mirror 46 side. And a relay lens 45.

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

  The optical scanner 42 is disposed at a position optically conjugate with the pupil of the eye E to be examined. The optical scanner 42 deflects the measurement light LS passing through the OCT optical path. The optical scanner deflects the measurement light LS one-dimensionally or two-dimensionally. The optical scanner 42 includes, for example, a first galvanometer mirror and a second galvanometer mirror. The first galvanomirror deflects the measurement light LS so as to scan the imaging region (the fundus oculi Ef or the anterior segment) in a horizontal direction orthogonal to the optical axis of the interference optical system included in the OCT unit 100. The second galvanomirror deflects the measurement light LS deflected by the first galvanomirror so as to scan the imaging region in a vertical direction perpendicular to the optical axis of the interference optical system included in the OCT unit 100. Examples of the scanning mode of the measurement light LS by the optical scanner 42 include a horizontal scan, a vertical scan, a cross scan, a radiation scan, a circle scan, a concentric scan, and a spiral scan.

  The OCT focusing lens 43 is moved along the optical path of the measurement light LS in order to adjust the focus of the optical system for OCT. The OCT focusing lens 43 is used to arrange the first lens position for arranging the focal position of the measurement light LS at or near the fundus oculi Ef of the eye E, and to convert the measurement light LS applied to the eye E into a parallel light flux. And the second lens position. The movement of the photographing focusing lens 31, the movement of the focusing optical system 60, and the movement of the OCT focusing lens 43 can be controlled in a coordinated manner.

[OCT unit]
As illustrated in FIGS. 2 and 3, the OCT unit 100 is provided with an optical system for performing swept source OCT. This optical system includes an interference optical system. This interference optical system splits light from a wavelength-swept light source (variable-wavelength light source) into measurement light and reference light, and converts return light of measurement light from the eye E to be examined and reference light that has passed through a reference optical path. It has a function of generating interference light by superposition and a function of detecting this interference light. The detection result (detection signal) of the interference light obtained by the interference optical system is a signal indicating the spectrum of the interference light, and is sent to the arithmetic and control unit 200.

  As illustrated in FIG. 3, the light source unit 101 includes a light L0, which is a wavelength sweep light obtained by sweeping a predetermined wavelength range at a variable wavelength sweep speed, and a clock KC generated from the wavelength sweep light. Is output. Such a light source unit 101 includes a light source 140, optical splitters 141 and 142, a plurality of Mach-Zehnder interferometers (MZI) 143, and a light selection output device 144. The optical elements in the light source unit 101 are optically connected to each other via an optical fiber.

  The light source 140 is a wavelength sweep light source that outputs a wavelength sweep light in which the center wavelength of the emitted light changes at high speed by sweeping a predetermined wavelength range at a variable wavelength sweep speed. The light source 140 includes, for example, a near-infrared tunable laser.

  The optical splitter 141 splits the wavelength-swept light emitted from the light source 140 into light L0 and light for clock generation. The light L0 split by the optical splitter 141 is guided to the polarization controller 103 by the optical fiber 102, as described later. The clock generation light split by the optical splitter 141 is guided to the optical splitter 142 by an optical fiber. The optical splitter 142 splits the clock generation light into a plurality of split lights (for example, split lights for the number of measurement modes). The plurality of split lights split by the optical splitter 142 are respectively guided to any of the plurality of MZIs 143 by optical fibers.

  The MZI 143 further splits the split light split by the optical splitter 142 into two, and synthesizes two optical paths via different optical paths, thereby outputting a synthetic light corresponding to the optical path length difference between the optical paths. I do. The plurality of MZIs 143 are configured such that optical path length differences are different from each other in accordance with the wavelength sweep speed. The light selection output unit 144 selectively outputs the combined light from the plurality of MZIs 143 as a clock KC based on the wavelength sweep speed.

  In some embodiments, a plurality of MZIs 143 are provided for a number of measurement speeds that can be changed (a number of wavelength sweep speeds). In some embodiments, a plurality of MZIs 143 are provided for the number of measurement ranges that can be switched by changing the measurement speed. In this embodiment, two MZIs 143 corresponding to the first measurement speed and the second measurement speed are provided.

  By configuring the plurality of MZIs 143 so that the optical path length differences are different from each other according to the measurement speed, and by selectively outputting the combined light according to the wavelength sweep speed by the light selection output device 144, the wavelength sweep speed is increased. Can be output. As a result, the clock KC output from the light selection output device 144 is output as a clock having a constant frequency (period). Note that the number of MZIs 143 is arbitrary as long as the clock KC can be output as a clock having a certain frequency.

  As shown in FIG. 2, the light L0 output from the light source unit 101 is guided to a polarization controller 103 by an optical fiber 102, and the polarization state thereof is adjusted. The light L0 whose polarization state has been adjusted is guided to the fiber coupler 105 by the optical fiber 104, and is split into the measurement light LS and the reference light LR.

  The reference light LR is guided by an optical fiber 110 to a collimator 111, converted into a parallel light flux, and guided to a corner cube 114 via an optical path length correction member 112 and a dispersion compensation member 113. The optical path length correction member 112 acts to match the optical path length of the reference light LR with the optical path length of the measurement light LS. The dispersion compensating member 113 acts to match the dispersion characteristics between the reference light LR and the measurement light LS. The corner cube 114 is movable in the direction of incidence of the reference light LR, thereby changing the optical path length of the reference light LR.

  The reference light LR that has passed through the corner cube 114 passes through the dispersion compensating member 113 and the optical path length correcting member 112, is converted from a parallel light beam into a focused light beam by the collimator 116, and enters the optical fiber 117. The reference light LR that has entered the optical fiber 117 is guided to the polarization controller 118 to adjust its polarization state, is guided to the attenuator 120 by the optical fiber 119, adjusts the light amount, and is guided to the fiber coupler 122 by the optical fiber 121. I will

  On the other hand, the measurement light LS generated by the fiber coupler 105 is guided by the optical fiber 127 and converted into a parallel light flux by the collimator lens unit 40, and is changed into an optical path length changing unit 41, an optical scanner 42, an OCT focusing lens 43, and a mirror 44. And a relay lens 45. The measurement light LS that has passed through the relay lens 45 is reflected by the dichroic mirror 46, refracted by the objective lens 22, and enters the eye E to be inspected. The measurement light LS is scattered and reflected at various depth positions of the eye E. The return light of the measurement light LS from the subject's eye E 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 the measurement light LS incident via the optical fiber 128 and the reference light LR incident via the optical fiber 121 to generate (interfere with) the interference light. The fiber coupler 122 generates a pair of interference lights LC by splitting the interference light at a predetermined split ratio (for example, 1: 1). The pair of interference lights LC is guided to the detector 125 through the optical fibers 123 and 124, respectively.

  The detector 125 is, for example, a balanced photodiode. The balanced photodiode includes a pair of photodetectors that respectively detect a pair of interference lights LC, and outputs a difference between a pair of detection results obtained by the photodetectors. The detector 125 sends this output (detection signal) to a DAQ (Data Acquisition System) 130.

  The DAQ 130 is supplied with a clock KC from the light source unit 101. As described above, the clock KC is a clock having a substantially constant frequency even when the wavelength sweep speed is changed in the light source unit 101. The DAQ 130 performs A / D conversion on the detection signal input from the detector 125 in synchronization with the clock KC, and samples the A / D conversion result as an interference signal. The DAQ 130 sends the interference signal obtained by the sampling to the arithmetic and control unit 200.

  In this example, an 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 for changing the length of the optical path (reference optical path, reference arm) of the reference light LR. Corner cube 114 is provided. However, only one of the optical path length changing unit 41 and the corner cube 114 may be provided. It is also possible to change the difference between the measured optical path length and the reference optical path length by using other optical members.

[Operation control unit]
The arithmetic and control unit 200 analyzes the detection signal input from the DAQ 130 and forms an OCT image of the fundus oculi Ef. The arithmetic processing for that is the same as in a conventional swept-source OCT apparatus.

  Further, the arithmetic and control unit 200 controls each unit of the fundus camera unit 2, the display device 3, and the OCT unit 100.

  As the control of the fundus camera unit 2, the arithmetic and control unit 200 controls the operation of the observation light source 11, the imaging light source 15, and the LEDs 51 and 61, the operation control of the LCD 39, the movement control of the imaging focus lens 31, and the control of the OCT focus lens 43. It performs movement control, movement control of the reflection bar 67, movement control of the focus optical system 60, movement control of the optical path length changing unit 41, operation control of the optical scanner 42, and the like.

  As control of the OCT unit 100, the arithmetic and control unit 200 performs operation control of the light source unit 101, operation control of the polarization controllers 103 and 118, operation control of the attenuator 120, operation control of the detector 125, operation control of the DAQ 130, and the like. .

  The arithmetic and control unit 200 includes, for example, a microprocessor, a RAM, a ROM, a hard disk drive, a communication interface, and the like, similarly to a conventional computer. A storage device such as a hard disk drive stores a computer program for controlling the ophthalmologic apparatus 1. The arithmetic and control unit 200 may include various circuit boards, for example, a circuit board for forming an OCT image. Further, the arithmetic and 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.

  The fundus camera unit 2, the display device 3, the OCT unit 100, and the arithmetic and control unit 200 may be configured integrally (that is, in a single housing), or may be configured separately in two or more housings. It may be.

(Control system)
4 and 5 show a configuration example of a control system of the ophthalmologic apparatus 1. FIG. 4 and 5, some of the components included in the ophthalmologic apparatus 1 are omitted. FIG. 5 is a block diagram illustrating a configuration example of the data processing unit 230 in FIG. The control unit 210, the image forming unit 220, and the data processing unit 230 are provided in, for example, the arithmetic and control unit 200.

(Control unit)
The control unit 210 performs various controls. Control unit 210 includes a main control unit 211 and a storage unit 212.

(Main control unit)
The main control unit 211 includes a processor and controls each unit of the ophthalmologic apparatus 1. For example, the main control unit 211 includes the optical path length changing unit 41 of the retinal camera unit 2, the optical scanner 42, the photographing focusing lens 31 (focus driving unit 31A), the focusing optical system 60, and the OCT focusing lens 43 (focusing). The controller 43A controls the image sensors 35 and 38, the LCD 39, the entire optical system (moving mechanism 150), and the like. Further, the main control unit 211 controls the light source unit 101, the corner cube 114 (reference driving unit 114A), the attenuator 120, the polarization controllers 103 and 118, the detector 125, the DAQ 130, and the like of the OCT unit 100. Further, the main control unit 211 controls the image forming unit 220 and the data processing unit 230.

  For example, the main control unit 211 displays the fixation target at a position on the screen of the LCD 39 corresponding to the fixation position set manually or automatically. The main control unit 211 can change the display position of the fixation target displayed on the LCD 39 (continuously or stepwise). Thereby, the fixation target can be moved (that is, the fixation position can be changed). The display position and the movement mode of the fixation target are set manually or automatically. The manual setting is performed using, for example, a GUI. The automatic setting is performed by the data processing unit 230, for example.

  The focusing drive unit 31 </ b> A moves the focusing lens 31 in the optical axis direction of the imaging optical system 30 and also moves the focusing optical system 60 in the optical axis direction of the illumination optical system 10. Thereby, the focus position of the photographing optical system 30 is changed. The focusing drive unit 31A may individually have a mechanism for moving the imaging focusing lens 31 and a mechanism for moving the focusing optical system 60. The focus drive unit 31A is controlled when performing focus adjustment or the like.

  The control of the optical scanner 42 includes control of the scanning position, scanning range or scanning speed by the first galvanomirror, control of the scanning position, scanning range or scanning speed by the second galvanomirror, and the like. The main control unit 211 can control the optical scanner 42 (at least one of the first galvanometer mirror and the second galvanometer mirror) according to the measurement speed of the OCT measurement. In some embodiments, a storage unit 212 described later stores scan information indicating a scan position, a scan range, a scan speed, or a scan mode in advance, and the main control unit 211 stores the scan information stored in the storage unit 212. It is possible to scan a desired part of the eye E based on the information.

  Further, the main control unit 211 can control the optical scanner 42 so as to scan a part specified by the user using the operation unit 240B described later. Further, the main control unit 211 can control the optical scanner 42 so as to scan the part specified by the data processing unit 230.

  The focusing drive unit 43A moves the OCT focusing lens 43 in the optical axis direction of the measurement optical path. Thereby, the focus position of the measurement light LS is changed. For example, by moving the OCT focusing lens 43 to the first lens position, the focusing position of the measurement light LS can be arranged at or near the fundus oculi Ef. For example, by moving the OCT focusing lens 43 to the second lens position, the focusing position of the measurement light LS can be arranged at a far point position, and the measurement light LS can be converted into a parallel light beam. The focus position of the measurement light LS corresponds to the depth position (z position) of the beam waist of the measurement light LS.

  The moving mechanism 150 moves at least the fundus camera unit 2 (optical system) three-dimensionally, for example. In a typical example, the moving mechanism 150 includes a mechanism for moving at least the fundus camera unit 2 in the x direction (lateral direction), a mechanism for moving in the y direction (vertical direction), and a mechanism for moving the fundus camera unit 2 in the z direction (depth direction). , A front-back direction). The mechanism for moving in the x direction includes, for example, an x stage that can move in the x direction, and an x moving mechanism that moves the x stage. The mechanism for moving in the y direction includes, for example, a y stage that can move in the y direction, and a y moving mechanism that moves the y stage. The mechanism for moving in the z direction includes, for example, a z stage that can move in the z direction, and a z moving mechanism that moves the z stage. Each moving mechanism includes an actuator such as a pulse motor and operates under the control of the main control unit 211.

  Control for the moving mechanism 150 is used in alignment and tracking. The tracking is to move the apparatus optical system in accordance with the eye movement of the eye E to be inspected. When performing tracking, alignment and focus adjustment are performed in advance. Tracking is a function of maintaining a suitable positional relationship where alignment and focus are achieved by causing the position of the apparatus optical system to follow eye movement. In some embodiments, it is configured to control the moving mechanism 150 to change the optical path length of the reference light (and thus the optical path length difference between the optical path of the measurement light and the optical path of the reference light).

  In the case of manual alignment, the user moves the optical system and the eye E relatively by operating the user interface 240 described below so that the displacement of the eye E with respect to the optical system is canceled. For example, the main control unit 211 controls the moving mechanism 150 by outputting a control signal corresponding to the operation content on the user interface 240 to the moving mechanism 150 to relatively move the optical system and the eye E to be inspected.

  In the case of auto alignment, the main control unit 211 controls the moving mechanism 150 such that the displacement of the eye E with respect to the optical system is canceled, thereby causing the optical system and the eye E to move relatively. In some embodiments, the main control unit 211 controls the control signal so that the optical axis of the optical system substantially coincides with the axis of the eye E and the distance of the optical system to the eye E is a predetermined working distance. Is output to the moving mechanism 150 to control the moving mechanism 150 to relatively move the optical system and the eye E to be examined. Here, the working distance is a predetermined value also called a working distance of the objective lens 22, and corresponds to a distance between the subject's eye E and the optical system at the time of measurement (at the time of photographing) using the optical system.

  Furthermore, the main control unit 211 can control the light source 140 of the light source unit 101 to change the wavelength sweep speed. In this case, the main control unit 211 can change the scanning speed of the optical scanner 42 according to the wavelength sweep speed.

  The main control unit 211 controls fundus photographing and anterior segment photographing by controlling the fundus camera unit 2 and the like. Further, the main control unit 211 controls the OCT measurement by controlling the fundus camera unit 2, the OCT unit 100, and the like. The main control unit 211 can execute a plurality of preliminary operations before performing the OCT measurement. Preliminary operations include alignment, coarse focus adjustment, polarization adjustment, and focus fine adjustment. The plurality of preliminary operations are performed in a predetermined order. In some embodiments, the preliminary actions are performed in the order described above.

  Note that the types and order of the preliminary operations are not limited to these, and are arbitrary. For example, a preliminary operation (small pupil determination) for determining whether or not the eye E to be examined is a small pupil eye can be added to the preliminary operation. The small pupil determination is performed, for example, between the coarse focus adjustment and the optical path length difference adjustment. In some embodiments, the small pupil determination includes the following series of processes: a process of acquiring a front image (anterior eye image) of the eye E; a process of identifying an image region corresponding to the pupil; Processing for determining the size (diameter, perimeter, etc.) of the pupil region obtained; processing for determining whether or not the eye is a small pupil based on the obtained size (threshold processing); The process to control. Some embodiments further include a process of approximating the pupil region with a circle or an ellipse to determine the pupil size.

  The focus rough adjustment is a focus adjustment using a split index. By determining the position of the focusing lens 31 based on the information obtained by associating the eye refractive power and the position of the focusing lens 31 acquired in advance and the measured value of the refractive power of the eye E, Focus coarse adjustment can also be performed.

  The focus fine adjustment is performed based on the interference sensitivity of the OCT measurement. For example, by monitoring the interference intensity (interference sensitivity) of the interference signal acquired by the OCT measurement of the eye E, the position of the OCT focusing lens 43 that maximizes the interference intensity is obtained, and the OCT focusing lens 43 is located at that position. By moving the focusing lens 43, fine focus adjustment can be performed.

  In the optical path length difference adjustment, control is performed such that a predetermined position in the eye E is a reference position of a measurement range in the depth direction. This control is performed for at least one of the optical path length changing unit 41 and the reference driving unit 114A. Thereby, the optical path length difference between the measurement optical path and the reference optical path is adjusted. The reference position of the measurement range in the depth direction is a position (a sclera rear position) rearward by a first distance (in a direction away from the objective lens 22) with respect to the sclera of the eye E to be examined when performing a fundus scan; There is a position in front of the cornea of the eye E when performing the anterior segment scan by a second distance (a direction closer to the objective lens 22). By setting the reference position by adjusting the optical path length difference, OCT measurement can be accurately performed in a desired measurement range in the depth direction only by changing the wavelength sweep speed.

  In the polarization adjustment, the polarization state of the reference light LR is adjusted in order to optimize the interference efficiency between the measurement light LS and the reference light LR.

  The main control unit 211, as a display control unit, displays, on the same screen of the display unit 240A, a plurality of images (OCT images) generated based on a plurality of OCT measurement results obtained by a plurality of OCT measurements at different measurement speeds. It can be displayed. In this case, the main control unit 211 can perform positioning of the plurality of generated images and superimpose and display at least a part of the plurality of aligned images. In addition, the main control unit 211 can display a plurality of images acquired by OCT measurement at different measurement speeds on the display unit 240A so as to be identifiable according to the measurement speed. This makes it possible to recognize which part (region, position) was measured at which measurement speed.

(Storage unit)
The storage unit 212 stores various data. The data stored in the storage unit 212 includes, for example, the above-described scanning information, image data of an OCT image, image data of a fundus image, eye information to be examined, and the like. The subject's eye information includes information about the subject, such as a patient ID and a name, and information about the subject's eye, such as left / right eye identification information. Further, the storage unit 212 stores various programs and data for operating the ophthalmologic apparatus 1.

(Image forming unit)
The image forming unit 220 forms an OCT image of the eye E based on sampling data obtained by sampling the detection signal from the detector 125 with the DAQ 130. The OCT image formed by the image forming unit 220 includes an A-scan image, a B-scan image (tomographic image), a C-scan image, and the like. This processing includes processing such as noise removal (noise reduction), filtering, dispersion compensation, and FFT (Fast Fourier Transform), as in the conventional swept-source OCT. In the case of another type of OCT apparatus, the image forming unit 220 executes a known process according to the type.

  The image forming unit 220 includes, for example, the above-described circuit board. In this specification, “image data” and “image” based on the image data may be identified.

(Data processing unit)
The data processing unit 230 processes data acquired by imaging of the eye E and OCT measurement. For example, the data processing unit 230 performs various image processing and analysis processing on the image formed by the image forming unit 220. For example, the data processing unit 230 executes various correction processes such as brightness correction of an image. Further, the data processing unit 230 performs various image processing and analysis processing on the image (fundus image, anterior eye image, etc.) obtained by the fundus camera unit 2.

  The data processing unit 230 performs known image processing such as interpolation processing for interpolating pixels between tomographic images, and forms image data of a three-dimensional image of the fundus oculi Ef. Note that the image data of a three-dimensional image refers to image data in which the positions of pixels are defined by a three-dimensional coordinate system. As image data of a three-dimensional image, there is image data composed of voxels arranged three-dimensionally. This image data is called volume data or voxel data. When displaying an image based on the volume data, the data processing unit 230 performs rendering processing (such as volume rendering or MIP (Maximum Intensity Projection: maximum value projection)) on the volume data to view the volume data from a specific line of sight. The image data of the pseudo three-dimensional image at the time of being formed is formed. This pseudo three-dimensional image is displayed on a display device such as the display unit 240A.

  Also, stack data of a plurality of tomographic images can be formed as image data of a three-dimensional image. Stack data is image data obtained by three-dimensionally arranging a plurality of tomographic images obtained along a plurality of scan lines based on the positional relationship of the scan lines. That is, the stack data is image data obtained by expressing a plurality of tomographic images originally defined by individual two-dimensional coordinate systems in one three-dimensional coordinate system (that is, embedding them in one three-dimensional space). is there.

  The data processing unit 230 performs various renderings on the acquired three-dimensional data set (volume data, stack data, and the like), and thereby performs a B-mode image (vertical cross-sectional image, axial cross-sectional image) on an arbitrary cross section, A C-mode image (transverse cross-sectional image, horizontal cross-sectional image), a projection image, a shadowgram, and the like can be formed. An image of an arbitrary cross section such as a B-mode image or a C-mode image is formed by selecting a pixel (pixel, voxel) on a specified cross section from a three-dimensional data set. The projection image is formed by projecting the three-dimensional data set in a predetermined direction (z direction, depth direction, axial direction). The shadowgram is formed by projecting a part of the three-dimensional data set (for example, partial data corresponding to a specific layer) in a predetermined direction. An image, such as a C-mode image, a projection image, or a shadowgram, which is viewed from the front side of the subject's eye is referred to as a front image (en-face image).

  The data processing unit 230 generates a B-mode image in which a retinal blood vessel or a choroidal blood vessel is enhanced or a front image (a blood vessel enhanced image, an angiogram, an angiogram, or the like) based on data (for example, B-scan image data) collected in time series by OCT. OCTA image) can be constructed. For example, time-series OCT data can be collected by repeatedly scanning substantially the same site of the eye E.

  In some embodiments, the data processing unit 230 compares the time-series B-scan images obtained by the B-scan for substantially the same site, and converts a pixel value of at least one change portion of the signal intensity and the phase into a change amount. By converting to a corresponding pixel value, an emphasized image in which the changed portion is emphasized is constructed. Further, the data processing unit 230 forms an OCTA image by extracting information of a predetermined thickness at a desired part from the constructed plurality of emphasized images and constructing the information as an en-face image.

  As shown in FIG. 5, the data processing unit 230 includes a determination unit 231, a motion contrast generation unit 232, an OCTA image forming unit 233, and an analysis unit 234.

  The determination unit 231 analyzes the detection result of the interference light obtained by the OCT measurement, and determines the focus state of the measurement light LS in the focus fine adjustment control. For example, the main control unit 211 performs repetitive OCT measurement while controlling the focus driving unit 43A according to a predetermined algorithm. The determination unit 231 calculates a predetermined evaluation value regarding the image quality of the OCT image by analyzing the detection result of the interference light LC repeatedly acquired by the OCT measurement. The determination unit 231 determines whether the calculated evaluation value is equal to or less than a threshold. In some embodiments, the focus fine adjustment is continued until the calculated evaluation value falls below the threshold. That is, when the evaluation value is equal to or less than the threshold value, it is determined that the focus state of the measurement light LS is appropriate, and the focus fine adjustment is continued until it is determined that the focus state of the measurement light LS is appropriate.

  In some embodiments, the main control unit 211 monitors the strengths (interference strength, interference sensitivity) of the sequentially obtained interference signals while performing the above-described repetitive OCT measurement to obtain the interference signals. I do. Further, by moving the OCT focusing lens 43 while performing this monitoring process, the position of the OCT focusing lens 43 that maximizes the interference intensity is searched. According to such fine focus adjustment, the OCT focusing lens 43 can be guided to a position where the interference intensity is optimized.

  The determination unit 231 analyzes the detection result of the interference light obtained by the OCT measurement, and determines the polarization state of at least one of the measurement light LS and the reference light LR. For example, the main control unit 211 performs repetitive OCT measurement while controlling at least one of the polarization controllers 103 and 118 according to a predetermined algorithm. In some embodiments, the main control unit 211 controls the attenuator 120 to change the amount of attenuation of the reference light LR. The determination unit 231 calculates a predetermined evaluation value regarding the image quality of the OCT image by analyzing the detection result of the interference light LC repeatedly acquired by the OCT measurement. The determination unit 231 determines whether the calculated evaluation value is equal to or less than a threshold. This threshold is set in advance. The polarization adjustment is continued until the calculated evaluation value becomes equal to or less than the threshold. That is, when the evaluation value is equal to or less than the threshold value, it is determined that the polarization state of the measurement light LS is appropriate, and the polarization adjustment is continued until it is determined that the polarization state of the measurement light LS is appropriate.

  In some embodiments, the main control unit 211 can monitor the interference intensity even in polarization adjustment.

  The motion contrast generation unit 232 generates motion contrast data based on a plurality of OCT measurement results obtained by repeatedly performing OCT measurement on the same part of the eye E. The motion contrast data is data representing a temporal change between a plurality of OCT measurement results at a measurement site. The motion contrast data represents, for example, a temporal change in blood flow or the like at the measurement site.

  The motion contrast generation unit 232 can generate motion contrast data based on a change in amplitude information or phase information in a plurality of OCT measurement results. In some embodiments, the motion contrast generator 232 generates motion contrast data based on changes in both amplitude information and phase information in a plurality of OCT measurement results. The motion contrast generation unit 232 is described in, for example, Non-Patent Document 1 (“Methods and algorithms for optical coherence tomography-based angiography: a review and a method disclosed in a plurality of methods described in Anqi Zhan and others in the method of Anqi and others” in “Review and companion”). Motion contrast data can be generated based on a change in amplitude information, phase information, or both amplitude information and phase information in a measurement result.

  For example, when generating motion contrast data based on a change in amplitude information in a plurality of OCT measurement results, the main control unit 211 causes the image forming unit 220 to form a tomographic image from the OCT measurement results obtained by each OCT measurement. . Next, the main control unit 211 controls the motion contrast generation unit 232 to perform alignment between the plurality of tomographic images formed by the image forming unit 220, and performs the alignment between the plurality of aligned tomographic images. Then, three-dimensional motion contrast data is generated by specifying the motion contrast in.

  The motion contrast generator 232 includes a first data generator 232A and a second data generator 232B.

  The first data generation unit 232A performs the first data generation based on a plurality of OCT measurement results obtained by repeatedly executing the OCT measurement at a first measurement speed on a predetermined measurement site (first measurement site) in the eye E. 1. Generate contrast data. The predetermined measurement site is a site set in advance or a site specified in advance by the user using the operation unit 240B. For example, the first data generation unit 232A performs alignment between a plurality of tomographic images formed based on a plurality of OCT results by the image forming unit 220, and performs motion contrast between the plurality of aligned tomographic images. Is generated to generate first motion contrast data.

  The second data generation unit 232B is obtained by repeatedly performing the OCT measurement at the second measurement speed on the re-measurement part (the second measurement part) of the eye E specified based on the first motion contrast data. The second contrast data is generated based on the plurality of OCT measurement results. The remeasurement part is a part specified as a part to be remeasured based on the first motion contrast data. In some embodiments, the remeasurement part displays an image (for example, an OCTA image described later) formed based on the first motion contrast data on the display unit 240A, and refers to the doctor or the like while referring to the displayed image. Are parts designated by the user using the operation unit 240B. In some embodiments, the remeasurement site is a site specified by the analysis unit 234 analyzing the first motion contrast data. For example, similarly to the first data generating unit 232A, the second data generating unit 232B performs positioning between a plurality of tomographic images formed based on a plurality of OCT results by the image forming unit 220, and performs positioning. The second motion contrast data is generated by specifying the motion contrast between the plurality of obtained tomographic images.

  In some embodiments, the second measurement speed is lower than the first measurement speed. In the configuration of FIG. 3, since the measurement range in the depth direction is widened even when the wavelength sweep speed is changed to a low speed, the tomographic image or OCTA image obtained by the OCT measurement at the first measurement speed and the second measurement There is no hindrance in positioning and combining with the tomographic image or OCTA image obtained by the OCT measurement of the velocity.

  In some embodiments, the re-measurement part (second measurement part) is a part of the OCT measurement part (first measurement part) executed to acquire the first motion contrast data.

  The OCTA image forming section 233 forms an OCTA image based on the motion contrast data generated by the motion contrast generating section 232. The OCTA image forming unit 233 forms an OCTA image by projecting motion contrast data in a predetermined depth range of the motion contrast data onto a desired two-dimensional plane. The OCTA image forming unit 233 forms an OCTA image by projecting, for example, motion contrast data in a depth range designated by the main control unit 211 onto a predetermined two-dimensional plane. Examples of the depth range include a range including blood vessels in the shallow retina, a range including blood vessels in the deep retina, a range including blood vessels in a layer between the shallow retina and the deep layer in the retina, and a range including blood vessels in the entire retina. For example, it is possible to form a blood vessel image representing a position where a blood flow has occurred from the motion contrast data on the fundus oculi Ef.

  The analysis unit 234 performs a predetermined analysis process on the detection result of the interference light obtained by the OCT measurement or the OCT image formed based on the detection result. In the predetermined analysis processing, a specified part (tissue, lesion) in the eye E to be examined is specified; a distance (interlayer distance), an area, an angle, a ratio, and a density between the specified parts are calculated; Calculation of a predetermined part; calculation of these statistical values; calculation of the distribution of measured values and statistical values; image processing based on the results of these analysis processes. Certain tissues include blood vessels, optic disc, fovea, macula, and the like. Predetermined lesions include vitiligo, bleeding, and the like.

  In addition, the analysis unit 234 can specify a part (position, area) to be re-measured based on the motion contrast data generated by the motion contrast generation unit 232. The main control unit 211 designates the part specified by the analysis unit 234 as a remeasurement part (second measurement part), and causes the designated remeasurement part to execute OCT remeasurement.

  In some embodiments, the analysis unit 234 identifies a part to be re-measured by analyzing an image formed based on the motion contrast data. For example, the analysis unit 234 specifies a part to be re-measured by analyzing the OCTA image formed based on the motion contrast data by the OCTA image forming unit 233. Specifically, the analysis unit 234 specifies, as a part to be re-measured, a part corresponding to a region whose spatial frequency is equal to or less than a predetermined threshold in the formed OCTA image.

  In some embodiments, the analysis unit 234 specifies a part to be re-measured based on the intensity image and the phase image formed based on the motion contrast data. In this case, the OCTA image forming unit 233 forms an intensity image based on the amplitude information of the first motion contrast data, and forms a phase image based on the phase information of the first motion contrast data. The analysis unit 234 performs position alignment between the intensity image and the phase image, and specifies a portion to be re-measured by comparing the aligned images. For example, the analysis unit 234 includes a portion corresponding to a region which is depicted in the intensity image but is not depicted in the phase image, a region corresponding to a region which is not depicted in the intensity image but is depicted in the phase image, or A part corresponding to a region not depicted in both the intensity image and the phase image is specified as a part to be re-measured.

  In some embodiments, the analysis unit 234 specifies a part to be remeasured by analyzing a front image of the eye E to be examined. The front image includes a fundus image acquired by the fundus camera unit 2, a C-mode image (C-scan image), a projection image, a shadowgram, a fluorescein fluorescent image, an indocyanine green fluorescent image, a spontaneous fluorescent image, and the like. In some embodiments, the fluorescein fluorescent image, indocyanine green fluorescent image, or spontaneous fluorescent image is an image separately acquired by another device.

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

(User interface)
The user interface 240 includes a display unit 240A and an operation unit 240B. The display unit 240A includes the display device and the display device 3 of the arithmetic and control unit 200 described above. The operation unit 240B includes the operation device of the arithmetic and control unit 200 described above. The operation unit 240B may include various buttons and keys provided on the housing of the ophthalmologic apparatus 1 and on the outside. For example, when the fundus camera unit 2 has a housing similar to a conventional fundus camera, the operation unit 240B may include a joystick, an operation panel, and the like provided in this housing. The display unit 240A may include various display devices such as a touch panel provided on the housing of the retinal camera unit 2.

  The display unit 240A and the operation unit 240B do not need to be configured as separate devices. For example, a device in which a display function and an operation function are integrated, such as a touch panel, can be used. In that case, the operation unit 240B includes the touch panel and the computer program. The content of the operation performed on the operation unit 240B is input to the control unit 210 as an electric signal. Further, operations and information input may be performed using a graphical user interface (GUI) displayed on the display unit 240A and the operation unit 240B.

  The optical system and the control unit 210 included in the OCT unit 100 are an example of the “OCT measurement unit” according to the embodiment. The control unit 210 (main control unit 211) is an example of the “part specifying unit” according to the embodiment. The control unit 210 (main control unit 211) is an example of the “display control unit” according to the embodiment.

[motion]
An operation of the ophthalmologic apparatus 1 according to the embodiment will be described.

(First operation example)
In the first operation example, the user performs an operation based on first motion contrast data obtained by performing OCT measurement at a first measurement speed on a predetermined part (first measurement part) of the fundus oculi Ef of the eye E to be inspected. A remeasurement site (second measurement site) is designated using the operation unit 240B. The second motion contrast data is generated by executing the OCT measurement on the re-measurement part at the second measurement speed.

  FIG. 6 shows a flowchart of a first operation example of the ophthalmologic apparatus 1 according to the embodiment. The storage unit 212 stores a computer program for implementing the processing illustrated in FIG. The main control unit 211 executes the processing shown in FIG. 6 by operating according to the computer program.

(S1: Set the wavelength sweep speed to the first measurement speed)
The main controller 211 sets the wavelength sweep speed for the light source 140 of the light source unit 101 to the first measurement speed. Thereby, the light source 140 can start a predetermined wavelength range sweep at the set wavelength sweep speed.

(S2: alignment)
The main controller 211 executes the alignment. That is, the main control unit 211 controls the alignment optical system 50 to project the alignment index on the eye E to be inspected. At this time, a fixation target by the LCD 39 is also projected on the eye E to be examined. The main control unit 211 controls the moving mechanism 150 based on the moving amount of the optical system specified based on, for example, the received light image acquired by the image sensor 35, and moves the optical system to the eye E by the moving amount. Move relatively. The main control unit 211 repeatedly executes this processing.

  In some embodiments, the above-described rough alignment adjustment and fine alignment adjustment are performed before the completion of the alignment in Step S2.

(S3: Obtain adjustment tomographic image)
Subsequently, the main control unit 211 controls the OCT unit 100 to execute the OCT temporary measurement, and acquires an adjustment tomographic image for adjusting the reference position in the depth direction. More specifically, the main controller 211 controls the optical scanner 42 to deflect the measurement light LS generated based on the light L0 emitted from the light source unit 101, and receives the measurement light LS with the deflected measurement light LS. A predetermined part (for example, fundus) of the optometry E is scanned. The detection result of the interference light obtained by scanning the measurement light LS is sent to the image forming unit 220 after being sampled in synchronization with the clock KC. The image forming unit 220 forms a tomographic image (OCT image) of the eye E from the obtained interference signal.

(S4: Adjust the reference position in the depth direction)
Subsequently, the main control unit 211 adjusts the reference position of the measurement range in the depth direction (z direction). Specifically, the main control unit 211 causes the analysis unit 234 to specify a predetermined portion (for example, sclera) in the tomographic image obtained in step S3, and sets the depth of the specified position to the specified position. A position separated by a predetermined distance in the direction is set as a reference position of the measurement range.

(S5: focus adjustment, polarization adjustment)
Next, the main control unit 211 executes focus adjustment control and polarization adjustment control.

  For example, the main control unit 211 controls the focusing drive unit 43A to move the OCT focusing lens 43 by a predetermined distance, and then controls the OCT unit 100 to execute OCT measurement. As described above, the main control unit 211 causes the determination unit 231 to determine the focus state of the measurement light LS based on the detection result of the interference light obtained by the OCT measurement. When it is determined based on the determination result by the determination unit 231 that the focus state of the measurement light LS is not appropriate, the main control unit 211 controls the focus driving unit 43A again, and determines that the focus state is appropriate. Repeat until done.

  Further, for example, the main control unit 211 controls at least one of the polarization controllers 103 and 118 to change the polarization state of at least one of the light L0 and the measurement light LS by a predetermined amount, and then controls the OCT unit 100. Then, the OCT measurement is executed, and the OCT image based on the obtained interference light detection result is formed by the image forming unit 220. The main control unit 211 causes the determination unit 231 to determine the image quality of the OCT image obtained by the OCT measurement as described above. When it is determined that the polarization state of the measurement light LS is not appropriate based on the determination result by the determination unit 231, the main control unit 211 controls the polarization controllers 103 and 118 again, and determines that the polarization state is appropriate. Repeat until it is determined that there is.

(S6: Obtain interference signal)
Subsequently, the main control unit 211 controls the OCT unit 100 to repeatedly execute the OCT measurement on a predetermined part of the fundus oculi Ef of the eye E to be set in advance. The detection result of the interference light obtained by each OCT measurement is sampled by the DAQ 130 and stored in the storage unit 212 or the like as an interference signal each time.

(S7: OCTA image is formed)
The main control unit 211 causes the image forming unit 220 to form a tomographic image based on the interference signal acquired in step S6. The main control unit 211 causes the image forming unit 220 to form a tomographic image every time OCT measurement is performed on a predetermined part. Thereby, a plurality of tomographic images are formed corresponding to a plurality of OCT measurements repeatedly performed at a first measurement speed on a predetermined site.

  Subsequently, the main control unit 211 controls the first data generation unit 232A to perform positioning between the obtained plurality of tomographic images, and obtains a motion contrast between the plurality of aligned tomographic images. By specifying, the first motion contrast data is generated. Further, the main control unit 211 controls the OCTA image forming unit 233 to form an OCTA image by projecting the first motion contrast data in a preset depth range onto a predetermined two-dimensional plane.

(S8: display)
The main control unit 211 causes the display unit 240A to display the OCTA image formed in step S7.

(S9: Specify re-measurement site)
Next, the main control unit 211 receives designation of a remeasurement site by the user using the operation unit 240B. The user can specify a remeasurement site for the OCTA image displayed on the display unit 240A. For example, the main control unit 211 controls the analysis unit 234 to specify the position of the remeasurement part specified using the operation unit 240B from the coordinate position of each pixel in the OCTA image, and determines the fundus oculi from the specified position. It is possible to specify the scanning position at Ef.

(S10: Set the wavelength sweep speed to the second measurement speed)
The main control unit 211 sets the wavelength sweep speed to the second measurement speed for the light source 140 of the light source unit 101, as in step S1. The second measurement speed is lower than the first measurement speed. Thereby, the light source 140 can start a predetermined wavelength range sweep at the set wavelength sweep speed. Since the light selection output unit 144 of the light source unit 101 selectively outputs the combined light from the MZI 143 corresponding to the set wavelength sweep speed, the frequency of the clock KC does not change.

(S11: alignment)
The main control unit 211 executes the alignment as in step S2.

(S12: Obtain adjustment tomographic image)
Subsequently, the main control unit 211 controls the OCT unit 100 to execute the OCT temporary measurement and obtain an adjustment tomographic image for adjusting the reference position in the depth direction, similarly to step S3.

(S13: Adjust the reference position in the depth direction)
Subsequently, the main control unit 211 adjusts the reference position of the measurement range in the depth direction (z direction) as in step S4.

(S14: focus adjustment, polarization adjustment)
Next, the main control unit 211 executes focus adjustment control and polarization adjustment control as in step S5.

(S15: Obtain interference signal)
Subsequently, the main control unit 211 controls the OCT unit 100 to repeatedly execute the OCT measurement on the remeasurement part specified in step S9, as in step S6. The detection result of the interference light obtained by each OCT measurement is sampled by the DAQ 130 and stored in the storage unit 212 or the like as an interference signal each time.

(S16: OCTA image is formed)
The main control unit 211 causes the image forming unit 220 to form a tomographic image based on the interference signal acquired in step S15, as in step S7. The main control unit 211 causes the image forming unit 220 to form a tomographic image every time the OCT measurement is performed on the re-measurement part. Thereby, a plurality of tomographic images are formed corresponding to a plurality of OCT measurements repeatedly performed on the re-measurement site at the second measurement speed.

  Subsequently, the main control unit 211 controls the second data generation unit 232B to perform alignment between the obtained tomographic images, and obtains a motion contrast between the aligned tomographic images. By specifying, the second motion contrast data is generated. Further, the main control unit 211 controls the OCTA image forming unit 233 to form an OCTA image by projecting the second motion contrast data in a preset depth range onto a predetermined two-dimensional plane.

(S17: display)
The main control unit 211 causes the display unit 240A to display the OCTA image formed in step S16. The main control unit 211 can display the OCTA image formed in step S16 so as to be superimposed on the OCTA image displayed in step S8.

  FIG. 7 schematically shows the OCTA image displayed in step S16. FIG. 7 schematically shows a case where the OCTA image IMG2 formed in step S16 is superimposed and displayed on the OCTA image IMG1 formed in step S7.

  For example, in the OCTA image IMG1 displayed in step S8, the main control unit 211 specifies a position corresponding to the remeasurement part specified in step S9, and the OCTA image IMG2 formed in step S16 at the specified position. Is displayed.

  This is the end of the operation of the ophthalmologic apparatus 1 (end).

(Second operation example)
In the second operation example, a remeasurement part is determined by the analysis unit 234 based on the first motion contrast data obtained by performing the OCT measurement at a first measurement speed on a predetermined part of the fundus oculi Ef of the eye E to be inspected. It is specified. The second motion contrast data is generated by executing the OCT measurement on the re-measurement part at the second measurement speed.

  FIG. 8 shows a flowchart of a second operation example of the ophthalmologic apparatus 1 according to the embodiment. The storage unit 212 stores a computer program for implementing the processing illustrated in FIG. The main control unit 211 executes the processing shown in FIG. 8 by operating according to the computer program.

(S21: Set the wavelength sweep speed to the first measurement speed)
The main control unit 211 sets the wavelength sweep speed for the light source 140 of the light source unit 101 to the first measurement speed, as in step S1.

(S22: alignment)
The main controller 211 executes the alignment as in step S2.

(S23: Obtain adjustment tomographic image)
Subsequently, the main control unit 211 controls the OCT unit 100 to execute the OCT temporary measurement and obtain an adjustment tomographic image for adjusting the reference position in the depth direction, similarly to step S3.

(S24: Adjust the reference position in the depth direction)
Subsequently, the main control unit 211 adjusts the reference position of the measurement range in the depth direction (z direction) as in step S4.

(S25: focus adjustment, polarization adjustment)
Next, the main control unit 211 executes focus adjustment control and polarization adjustment control as in step S5.

(S26: Obtain interference signal)
Subsequently, the main control unit 211 controls the OCT unit 100 to repeatedly execute the OCT measurement on a predetermined part of the fundus oculi Ef of the eye to be inspected E, similarly to step S6.

(S27: OCTA image is formed)
The main control unit 211 causes the image forming unit 220 to form a tomographic image based on the interference signal acquired in step S26, as in step S7. Thereby, a plurality of tomographic images are formed corresponding to a plurality of OCT measurements repeatedly performed at a first measurement speed on a predetermined site.

  Subsequently, the main control unit 211 controls the first data generation unit 232A to perform positioning between the obtained plurality of tomographic images, and obtains a motion contrast between the plurality of aligned tomographic images. By specifying, first motion contrast data is generated. Further, the main control unit 211 controls the OCTA image forming unit 233 to form an OCTA image by projecting the first motion contrast data in a preset depth range onto a predetermined two-dimensional plane.

(S28: analysis)
The main control unit 211 analyzes the OCTA image formed in step S27, and causes the analysis unit 234 to specify a part to be re-measured. The analysis unit 234 specifies a part to be re-measured by signal processing or image processing as described above. In some embodiments, the main control unit 211 causes the analysis unit 234 to specify a part to be re-measured by analyzing the motion contrast data generated in step S27.

(S29: Remeasurement site is specified)
Next, the main control unit 211 specifies the position of the remeasurement site specified by the analysis unit 234 from the coordinate position of each pixel in the OCTA image formed in step S27, and scans the fundus Ef from the specified position. To identify.

(S30: Set the wavelength sweep speed to the second measurement speed)
The main control unit 211 sets the wavelength sweep speed to the second measurement speed for the light source 140 of the light source unit 101, as in step S10. The second measurement speed is lower than the first measurement speed.

(S31: alignment)
The main control unit 211 executes the alignment as in step S11.

(S32: Obtain adjustment tomographic image)
Subsequently, the main control unit 211 controls the OCT unit 100 to execute the OCT temporary measurement and obtain an adjustment tomographic image for adjusting the reference position in the depth direction, similarly to step S12.

(S33: Adjust the reference position in the depth direction)
Subsequently, the main control unit 211 adjusts the reference position of the measurement range in the depth direction (z direction) as in step S13.

(S34: focus adjustment, polarization adjustment)
Next, the main control unit 211 executes the focus adjustment control and the polarization adjustment control as in step S14.

(S35: Obtain interference signal)
Subsequently, the main control unit 211 controls the OCT unit 100 to repeatedly execute the OCT measurement on the remeasurement part specified in step S29, as in step S15. The detection result of the interference light obtained by each OCT measurement is sampled by the DAQ 130 and stored in the storage unit 212 or the like as an interference signal each time.

(S36: OCTA image is formed)
The main control unit 211 causes the image forming unit 220 to form a tomographic image based on the interference signal acquired in step S35, as in step S16. The main control unit 211 causes the image forming unit 220 to form a tomographic image every time the OCT measurement is performed on the re-measurement part. Thereby, a plurality of tomographic images are formed corresponding to a plurality of OCT measurements repeatedly performed on the re-measurement site at the second measurement speed.

  Subsequently, the main control unit 211 controls the second data generation unit 232B to perform alignment between the obtained tomographic images, and obtains a motion contrast between the aligned tomographic images. By specifying, the second motion contrast data is generated. Further, the main control unit 211 controls the OCTA image forming unit 233 to form an OCTA image by projecting the second motion contrast data in a preset depth range onto a predetermined two-dimensional plane.

(S37: display)
The main control unit 211 causes the display unit 240A to display the OCTA image formed in step S36, as in step S17. As shown in FIG. 7, the main control unit 211 can display the OCTA image formed in step S36 so as to be superimposed on the OCTA image formed in step S27.

  This is the end of the operation of the ophthalmologic apparatus 1 (end).

  In the above embodiment, the case where the measurement speed is changed by changing the wavelength sweep speed of the wavelength sweep light source in the swept source type OCT has been described. However, the configuration according to the embodiment is not limited to this. Absent.

  For example, the above embodiment can be applied to a spectral domain type OCT. In this case, the OCT unit 100 has a broadband light source, an interference optical system, and a spectroscope. The broadband light source outputs broadband light. As the broadband light source, for example, a super luminescent diode (SLD) is used. The interference optical system divides the light output from the broadband light source into the measurement light and the reference light, irradiates the measurement light with the eye E to be inspected, and generates the interference light between the return light of the measurement light from the eye E and the reference light. Detect with a spectrometer. The spectroscope spectrally decomposes the interference light generated by the interference optical system, detects the spectrum distribution, and generates an analog signal. The spectroscope includes an optical element (for example, a diffraction grating) that spectrally resolves the interference light and a photoelectric conversion element (for example, a line sensor) that detects the spectrally resolved interference light. The measurement speed (A scan speed) can be changed by changing at least one of the exposure time of the spectroscope and the data transfer speed of the detection result of the spectroscope.

[effect]
An ophthalmologic apparatus according to an embodiment and a control method thereof will be described.

  An ophthalmologic apparatus (1) according to some embodiments includes an OCT measurement unit (an optical system and a control unit 210 included in the OCT unit 100), a first data generation unit (232A), and a site designation unit (control unit 210). , A main control unit 211) and a second data generation unit (232B). The OCT measurement unit repeatedly performs the OCT measurement on the same part of the eye (E) at a changeable measurement speed. The first data generation unit generates first motion contrast data based on a plurality of measurement results obtained by repeating OCT measurement at a first measurement speed by the OCT measurement unit on a first measurement site of the subject's eye. . The part specifying unit is used to specify a second measurement part of the subject's eye based on the first motion contrast data. The second data generation unit is configured to perform a second motion contrast based on a plurality of measurement results obtained by repeating OCT measurement at a second measurement speed by the OCT measurement unit on the second measurement site specified by the site specification unit. Generate data.

  According to such a configuration, OCT measurement is performed on the first measurement site of the subject's eye at the first measurement speed to obtain first motion contrast data, and the first motion contrast data is designated based on the obtained first motion contrast data. The specified second measurement site is specified, and OCT measurement is performed on the specified second measurement site at the second measurement speed to obtain second motion contrast data. Thereby, a part such as a blood vessel that cannot be detected by the first motion contrast data can be detected by the second motion contrast data. As a result, even when the measurement speed is improved, it is possible to prevent a decrease in the OCTA detection sensitivity.

  The ophthalmologic apparatus according to some embodiments includes an operation unit (240B), and the site specification unit specifies a site specified using the operation unit as a second measurement site.

  According to such a configuration, since the second measurement site is specified using the operation unit, the region of interest that could not be detected at the first measurement speed is subjected to OCT measurement again at the second measurement speed, and the target region is detected. It is possible to confirm the form of the area and the like.

  The ophthalmologic apparatus according to some embodiments includes an analysis unit (234) that specifies a part to be remeasured by analyzing a front image of the eye to be inspected, and the part specification unit determines the part specified by the analysis unit. Designate as the second measurement site.

  According to such a configuration, since the analysis unit analyzes the front image of the eye to be examined and specifies the second measurement site, the attention area that cannot be detected at the first measurement speed is re-examined at the second measurement speed. By performing OCT measurement, it is possible to confirm the form and the like of the region of interest.

  An ophthalmologic apparatus according to some embodiments includes an analysis unit (234) that specifies a site to be remeasured by analyzing first motion contrast data, and the site specification unit determines the site specified by the analysis unit. Designate as the second measurement site.

  According to such a configuration, since the analysis unit specifies the second measurement site based on the first motion contrast data, the region of interest that could not be detected at the first measurement speed is again OCT detected at the second measurement speed. It is possible to confirm the form and the like of the region of interest by performing measurement.

  An ophthalmologic apparatus according to some embodiments includes an OCTA image forming unit (233) that forms a first OCTA image based on first motion contrast data, and the analyzing unit determines that the spatial frequency in the first OCTA image is equal to or less than a predetermined threshold. Is specified as a part to be re-measured.

  According to such a configuration, in the OCTA image formed based on the first motion contrast data, the region of interest that could not be detected at the first measurement speed is subjected to OCT measurement again at the second measurement speed, and It is possible to confirm the form and the like.

  In the ophthalmologic apparatus according to some embodiments, the OCTA image forming unit forms an intensity image based on the amplitude information of the first motion contrast data and forms a phase image based on the phase information of the first motion contrast data. Then, the analysis unit specifies a part to be re-measured based on the intensity image and the phase image.

  According to such a configuration, an intensity image and a phase image are formed on the first motion contrast data, and a portion to be re-measured is designated as the second measurement portion based on the intensity image and the phase image. OCT measurement is again performed at the second measurement speed on the region of interest that could not be detected, and the form of the region of interest can be confirmed.

  An ophthalmologic apparatus according to some embodiments includes: an OCTA image forming unit (233) that forms a first OCTA image based on the first motion contrast data and forms a second OCTA image based on the second motion contrast data; A display control unit (control unit 210, main control unit 211) for displaying the 1 OCTA image and the second OCTA image on the same screen of the display unit.

  According to such a configuration, the first OCTA image and the second OCTA image having different measurement speeds are displayed on the same screen of the display means, so that the difference in the form of the attention area due to the difference in measurement speed and the like are confirmed. It becomes possible.

  In the ophthalmologic apparatus according to some embodiments, the OCT measurement unit converts light (L0) from the wavelength sweep light source (light source 140) whose wavelength sweep speed can be changed into measurement light (LS) and reference light (LR). Includes an interference optical system that divides and irradiates the eye to be measured with measurement light, detects interference light (LC) between the return light of the measurement light from the eye and the reference light, and performs OCT measurement by changing the wavelength sweep speed. And a control unit (210, main control unit 211) for changing the measurement speed.

  According to such a configuration, in the swept-source OCTA, the wavelength sweep speed of the wavelength sweep light source is changed. Therefore, even when the measurement speed is improved, a decrease in the OCTA detection sensitivity can be easily prevented. Become like

  In the ophthalmologic apparatus according to some embodiments, the second measurement site is a part of the first measurement site.

  According to such a configuration, the region of interest in the first measurement region is measured, so that the region of interest that could not be detected at the first measurement speed is subjected to OCT measurement again at the second measurement speed, and the region of interest is measured. Can be confirmed.

  In the ophthalmologic apparatus according to some embodiments, the second measurement speed is lower than the first measurement speed.

  According to such a configuration, the region of interest is measured at a lower measurement speed, so that even when the measurement speed is improved, a decrease in the OCTA detection sensitivity can be easily prevented.

  A method for controlling an ophthalmologic apparatus (1) according to some embodiments includes a first measurement step, a first data generation step, a site designation step, a second measurement step, and a second data generation step. . In the first measurement step, OCT measurement is repeatedly performed on the first measurement site of the eye to be inspected (E) at the first measurement speed. The first data generation step generates first motion contrast data based on the plurality of measurement results obtained in the first measurement step. The part designation step is executed to designate a second measurement part of the subject's eye based on the first motion contrast data generated in the first data generation step. In the second measurement step, the OCT measurement is repeatedly performed at the second measurement speed on the second measurement part specified in the part specification step. The second data generation step generates second motion contrast data based on the plurality of measurement results obtained in the second measurement step.

  According to such control, the OCT measurement is performed on the first measurement site of the subject's eye at the first measurement speed to obtain the first motion contrast data, and the first motion contrast data is designated based on the obtained first motion contrast data. The specified second measurement site is specified, and OCT measurement is performed on the specified second measurement site at the second measurement speed to obtain second motion contrast data. Thereby, a part such as a blood vessel that cannot be detected by the first motion contrast data can be detected by the second motion contrast data. As a result, even when the measurement speed is improved, it is possible to prevent a decrease in the OCTA detection sensitivity.

  In the control method of the ophthalmologic apparatus according to some embodiments, the part specifying step specifies the part specified using the operation unit (240B) as the second measurement part.

  According to such control, since the second measurement site is specified using the operation unit, the region of interest that could not be detected at the first measurement speed is again OCT-measured at the second measurement speed, and the target region is detected. It is possible to confirm the form of the area and the like.

  The control method of the ophthalmologic apparatus according to some embodiments includes an analysis step of specifying a part to be re-measured by analyzing a front image of the subject's eye, and the part specification step includes setting the part specified in the analysis step. Designate as the second measurement site.

  According to such control, since the second measurement site is specified by analyzing the front image of the eye to be examined in the analysis step, the region of interest that could not be detected at the first measurement speed is again analyzed at the second measurement speed. By performing OCT measurement, it is possible to confirm the form and the like of the region of interest.

  The control method of the ophthalmologic apparatus according to some embodiments includes an analysis step of specifying a part to be re-measured by analyzing the first motion contrast data, and the part specification step includes the step of specifying the part specified in the analysis step. Designate as the second measurement site.

  According to such control, since the second measurement site is specified based on the first motion contrast data in the analysis step, the attention area that cannot be detected at the first measurement speed is again OCT detected at the second measurement speed. It is possible to confirm the form and the like of the region of interest by performing measurement.

  A method of controlling an ophthalmologic apparatus according to some embodiments includes an OCTA image forming step of forming a first OCTA image based on first motion contrast data, and the analyzing step includes a step in which a spatial frequency in the first OCTA image is equal to or less than a predetermined threshold. Is specified as a part to be re-measured.

  According to such control, in the OCTA image formed based on the first motion contrast data, the region of interest that could not be detected at the first measurement speed is subjected to OCT measurement again at the second measurement speed, and It is possible to confirm the form and the like.

  In an ophthalmologic apparatus control method according to some embodiments, the OCTA image forming step forms an intensity image based on amplitude information of the first motion contrast data, and forms a phase image based on phase information of the first motion contrast data. An image is formed, and the analysis step specifies a part to be remeasured based on the intensity image and the phase image.

  According to such control, an intensity image and a phase image are formed on the first motion contrast data, and a part to be re-measured is designated as the second measurement part based on the intensity image and the phase image. OCT measurement is again performed at the second measurement speed on the region of interest that could not be detected, and the form of the region of interest can be confirmed.

  The method of controlling an ophthalmologic apparatus according to some embodiments includes an OCTA image forming step of forming a first OCTA image based on the first motion contrast data, and forming a second OCTA image based on the second motion contrast data. A display control step of displaying the 1 OCTA image and the second OCTA image on the same screen of the display means (display section 240A).

  According to such control, the first OCTA image and the second OCTA image having different measurement speeds are displayed on the same screen of the display means, so that a difference in the form of the attention area due to the difference in measurement speed is confirmed. It becomes possible.

  In the control method of the ophthalmologic apparatus according to some embodiments, the first measurement step and the second measurement step include measuring the light (L0) from the wavelength sweep light source (light source 140) whose wavelength sweep speed can be changed to the measurement light (LS). ) And a reference light (LR), irradiating the eye to be measured with measurement light, detecting return light of the measurement light from the eye to be examined and interference light (LC) between the reference light and the second measurement step, The measurement speed of the OCT measurement is changed by changing the wavelength sweep speed.

  According to such control, the wavelength sweep speed of the wavelength sweep light source is changed in the swept-source OCTA, so that even when the measurement speed is improved, a decrease in the OCTA detection sensitivity can be easily prevented. Become like

  In the above embodiment, the case where the detection result of the interference light in the wave number space is converted to the detection result of the interference light in the time space using the clock KC (that is, the k calibration method using the k clock) has been described. The configuration of the ophthalmologic apparatus 1 according to the embodiment is not limited to this. For example, an MZI interference signal for k calibration is obtained at the same time as an interference signal obtained by OCT measurement, and a known k calibration process is performed by the data processing unit 230 to convert a wave number space interference signal into a time space interference signal. May be converted to

  A computer program for implementing the above-described embodiment can be stored in any computer-readable recording medium. As the recording medium, for example, a semiconductor memory, an optical disk, a magneto-optical disk (CD-ROM / DVD-RAM / DVD-ROM / MO, etc.), a magnetic storage medium (hard disk / floppy (registered trademark) disk / ZIP, etc.), etc. Can be used.

  It is also possible to send and receive this program through a network such as the Internet or a LAN.

Reference Signs List 1 ophthalmic apparatus 2 fundus camera unit 10 illumination optical system 30 imaging optical system 42 optical scanner 50 alignment optical system 60 focus optical system 100 OCT unit 101 light source unit 140 light source 200 arithmetic control unit 210 control unit 211 main control unit 212 storage unit 220 image Forming unit 230 Data processing unit 231 Judgment unit 232 Motion contrast generation unit 232A First data generation unit 232B Second data generation unit 233 OCTA image formation unit 234 Analysis unit 240A Display unit 240B Operation unit E Eye to be examined LS Measurement light LR Reference light LC Interference light

Claims (18)

An OCT measurement unit that repeatedly executes the OCT measurement on the same part of the subject's eye at a changeable measurement speed;
A first data generation unit that generates first motion contrast data based on a plurality of measurement results obtained by repeating OCT measurement at a first measurement speed by the OCT measurement unit on a first measurement site of the eye to be inspected When,
A part specifying unit for specifying a second measurement part of the subject's eye based on the first motion contrast data;
The second motion contrast data is generated based on a plurality of measurement results obtained by repeating OCT measurement at a second measurement speed by the OCT measurement unit on the second measurement site specified by the site specification unit. A second data generator,
Ophthalmic equipment including. Including the operation unit,
The ophthalmologic apparatus according to claim 1, wherein the site specifying unit specifies a site specified using the operation unit as the second measurement site. Includes an analysis unit that specifies a site to be re-measured by analyzing the front image of the eye to be examined,
The ophthalmologic apparatus according to claim 1, wherein the site specifying unit specifies a site specified by the analysis unit as the second measurement site. An analysis unit that specifies a part to be re-measured by analyzing the first motion contrast data,
The ophthalmologic apparatus according to claim 1, wherein the site specifying unit specifies a site specified by the analysis unit as the second measurement site. An OCTA image forming unit that forms a first OCTA image based on the first motion contrast data,
5. The ophthalmologic apparatus according to claim 4, wherein the analysis unit specifies a region corresponding to a region where a spatial frequency is equal to or less than a predetermined threshold in the first OCTA image as the region to be re-measured. The OCTA image forming unit forms an intensity image based on the amplitude information of the first motion contrast data, and forms a phase image based on the phase information of the first motion contrast data.
The ophthalmologic apparatus according to claim 5, wherein the analysis unit specifies the part to be re-measured based on the intensity image and the phase image. An OCTA image forming unit that forms a first OCTA image based on the first motion contrast data and forms a second OCTA image based on the second motion contrast data;
A display control unit for displaying the first OCTA image and the second OCTA image on the same screen of a display unit;
The ophthalmologic apparatus according to any one of claims 1 to 4, comprising: The OCT measuring unit divides light from a wavelength sweep light source whose wavelength sweep speed can be changed into measurement light and reference light, irradiates the eye to be examined with the measurement light, and outputs the measurement light from the eye to be examined. Including an interference optical system for detecting interference light between the return light and the reference light,
The ophthalmologic apparatus according to any one of claims 1 to 7, further comprising a control unit configured to change a measurement speed of the OCT measurement by changing the wavelength sweep speed. The ophthalmologic apparatus according to any one of claims 1 to 8, wherein the second measurement site is a part of the first measurement site. The ophthalmologic apparatus according to any one of claims 1 to 9, wherein the second measurement speed is lower than the first measurement speed. A first measurement step of repeatedly executing OCT measurement at a first measurement speed on a first measurement site of the subject's eye;
A first data generation step of generating first motion contrast data based on the plurality of measurement results obtained in the first measurement step;
A part specifying step for specifying a second measurement part of the subject's eye based on the first motion contrast data generated in the first data generation step;
A second measurement step of repeatedly executing OCT measurement at a second measurement speed for the second measurement part specified in the part specification step;
A second data generation step of generating second motion contrast data based on the plurality of measurement results obtained in the second measurement step;
A method for controlling an ophthalmic apparatus including: The method of controlling an ophthalmologic apparatus according to claim 11, wherein, in the part specifying step, a part specified using an operation unit is specified as the second measurement part. Includes an analysis step of identifying a site to be remeasured by analyzing the front image of the eye to be examined,
The method of controlling an ophthalmologic apparatus according to claim 11, wherein the part specifying step specifies a part specified in the analysis step as the second measurement part. An analysis step of specifying a part to be re-measured by analyzing the first motion contrast data,
The method of controlling an ophthalmologic apparatus according to claim 11, wherein the part specifying step specifies a part specified in the analysis step as the second measurement part. An OCTA image forming step of forming a first OCTA image based on the first motion contrast data,
The method of controlling an ophthalmologic apparatus according to claim 14, wherein the analyzing step specifies a part corresponding to a region where a spatial frequency is equal to or less than a predetermined threshold in the first OCTA image as the part to be re-measured. The OCTA image forming step forms an intensity image based on the amplitude information of the first motion contrast data, and forms a phase image based on the phase information of the first motion contrast data;
The control method of the ophthalmologic apparatus according to claim 15, wherein the analyzing step specifies the part to be re-measured based on the intensity image and the phase image. An OCTA image forming step of forming a first OCTA image based on the first motion contrast data and forming a second OCTA image based on the second motion contrast data;
A display control step of displaying the first OCTA image and the second OCTA image on the same screen of display means;
The control method for an ophthalmologic apparatus according to any one of claims 11 to 14, comprising: The first measurement step and the second measurement step divide light from a wavelength sweep light source whose wavelength sweep speed can be changed into measurement light and reference light, irradiate the eye to be examined with the measurement light, and The return light of the measurement light from the optometry detects interference light with the reference light,
The control method for an ophthalmologic apparatus according to any one of claims 11 to 17, wherein the second measurement step changes a measurement speed of the OCT measurement by changing the wavelength sweep speed. .

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