JP7121510B2 - ophthalmic equipment - Google Patents

Description

The present invention relates to an ophthalmologic apparatus for examining blood vessel information in the anterior segment of the eye.

OCT angiography (OCTA) is known as a technique for examining the state of blood vessels in the fundus using OCT (optical coherence tomography) (for example, Non-Patent Document 1, Patent Documents 1 to 3). reference). This technique compares OCT images of the same location acquired with a time difference, extracts a portion with movement as a portion with blood flow, and images the blood vessel. This image is called an OCTA image, an angio image, a blood vessel enhanced image, a motion contrast image, or the like. Also, a technique is known in which this OCTA is applied to the anterior segment of the eye (see, for example, Non-Patent Document 2). There is basically no difference in hardware between OCT and OCTA, and the technical difference on the side of the ophthalmic apparatus lies in how the detected optical interference data is processed. Therefore, an OCTA image can be obtained by installing processing software for OCTA in a normal OCT apparatus. Of course, an ophthalmologic apparatus specialized for OCTA can also be realized.

Japan Ophthalmic Instruments Association 2017 Annual Report American Journal of Ophthalmology Case Reports 6 (2017) 24-26 Japanese Unexamined Patent Application Publication No. 2017-140302 JP 2017-6179 A Japanese Patent Application Laid-Open No. 2016-202900

OCTA performs multiple optical interference measurements on the same location with a time difference, so there is a problem that the measurement takes time. Especially in the case of the anterior segment, the scanning range becomes wider, so the measurement takes longer. This measurement time is currently about 10 to 30 seconds. This measurement time was a burden on the subject.

In view of this background, the present invention aims to shorten the examination time of OCT angiography (OCTA) targeting the anterior segment of the eye.

The present invention includes an OCT angiography data acquisition unit that acquires OCT angiography data of the anterior segment of an eye to be inspected, a visible light irradiation unit that irradiates the eye to be inspected with visible light when acquiring the OCT angiography data, The ophthalmologic apparatus further includes a notification unit that notifies whether or not fundus imaging is to be performed at a stage prior to the irradiation of the visible light .

The present invention provides an OCT angiography data acquisition unit that acquires OCT angiography data of the anterior segment of the subject 's eye to be examined, and an OCT angiography data acquisition unit that acquires the OCT angiography data of the other eye that is not the subject's eye. and a visible light irradiation unit that irradiates eyes with visible light .

The present invention comprises the steps of irradiating an eye to be inspected with visible light to constrict the pupil of the eye to be inspected, and acquiring OCT angiography data of the anterior segment of the eye to be inspected with the pupil contracted. and a step of notifying whether or not fundus imaging of the eye to be examined has been performed in a stage prior to the irradiation of the visible light .

The present invention comprises the steps of irradiating the other eye of a subject, which is not the eye to be examined, with visible light to reduce the pupil of the eye to be examined, and obtaining photographic data. The present invention is a program to be read and executed by a computer, comprising a step of causing a computer to irradiate an eye to be inspected with visible light to constrict a pupil of the eye to be inspected; A program for executing a step of acquiring OCT angiography data of the anterior segment of an eye to be inspected , and a step of informing the presence or absence of fundus imaging of the eye to be inspected in a stage prior to the irradiation of the visible light. .

The present invention is a program to be read and executed by a computer, wherein the computer irradiates the other eye of an examinee, which is not the eye to be examined, with visible light to reduce the pupil of the eye to be examined; acquiring OCT angiographic data of the anterior segment of the eye to be inspected in the contracted state.

1 is a configuration diagram of an ophthalmologic apparatus according to an embodiment; FIG. It is a block diagram of the OCT unit of embodiment. It is a block diagram of the arithmetic control unit of embodiment. FIG. 3 is a schematic diagram showing an eye to be inspected before (A) and after (B) pupillary constriction. 6 is a flow chart showing an example of a procedure of processing in the embodiment;

(Overview of Ophthalmic Device)
The ophthalmologic apparatus of this embodiment has a configuration in which an ophthalmologic camera and an OCTA apparatus are combined. Here, the OCTA apparatus of the present embodiment is capable of obtaining OCT images and OCT angiography (hereinafter referred to as OCTA images) of the fundus (posterior segment of the eye) and obtaining OCT images and OCTA images of the anterior segment of the eye. An OCTA device alone may be used as an ophthalmologic device using the present invention. Further, examples of ophthalmologic equipment that can be combined with the OCTA apparatus using the present invention include SLOs, slit lamps, microscopes for ophthalmic surgery, and the like.

As the principle of OCT to be used, a Fourier domain type is explained, but the principle of OCT is not limited, and other OCT methods such as spectral domain and swept source can also be used.

When acquiring an OCTA image of the anterior segment of the eye to be inspected, the ophthalmologic apparatus of the present embodiment reduces the pupil of the eye to be inspected, thereby narrowing the scanning range of the measurement light necessary for the OCTA image. By narrowing the scan range, the time required to acquire an OCTA image of the anterior segment (enhanced image of blood vessels in the anterior segment) is shortened.

Information on blood vessels in the anterior segment required for ophthalmologic examination and ophthalmologic treatment is obtained mainly from the vicinity of the boundary between the iris and pupil. Therefore, the smaller the pupil, the narrower the scan range required for creating OCTA can be set. Using this principle, the present embodiment reduces the scanning time required to create an OCTA compared to conventional techniques.

FIG. 1 shows an ophthalmologic apparatus 1 of this embodiment. The ophthalmologic apparatus 1 includes a fundus camera unit 2 , an OCTA unit 100 and an arithmetic control unit 200 . The retinal camera unit 2 has an optical system substantially similar to that of a conventional retinal camera. The OCTA unit 100 has an optical system for acquiring OCT and OCTA images of the fundus and anterior segment of the eye. The arithmetic control unit 200 is a computer that executes various kinds of arithmetic processing, control processing, and the like.

(fundus camera unit)
The fundus camera unit 2 has an illumination optical system 10 and an imaging optical system 30 . The illumination optical system 10 irradiates the fundus oculi Ef with illumination light used for photographing the fundus oculi. The photographing optical system 30 guides the fundus reflected light of this illumination light to a CCD image sensor 35 as an imaging device. Further, the imaging optical system 30 guides the OCT (and OCTA) measurement light from the OCTA unit 100 to the fundus oculi Ef, and transmits the OCT measurement light via the fundus oculi Ef (that is, the return light of the OCT measurement light from the fundus oculi Ef) to the OCTA. lead to unit 100; Further, the photographing optical system 30 guides the eye E to be examined with white light for contracting the pupil of the eye E to be examined.

The illumination optical system 10 has an observation illumination light source 11 . The observation illumination light source 11 outputs illumination light for the examiner to observe the fundus. The observation illumination light source 11 is composed of, for example, a halogen lamp or an LED. Light output from an observation illumination light source 11 (observation illumination light) is reflected by a reflecting mirror 12 having a curved reflecting surface, passes through a condenser lens 13, passes through a visible cut filter 14, and has a wavelength of 790 nm to 910 nm. of near-infrared light. Observation illumination light that has passed through the visible cut filter 14 is once converged in the vicinity of a photographing light source 15, which is a light source for photographing a fundus image, reflected by a mirror 16, and passed through relay lenses 17 and 18, a diaphragm 19, and a relay lens 20. to reach the perforated mirror 21 . The observation illumination light reaching the perforated mirror 21 is reflected by the periphery of the perforated mirror 21 (region around the perforation), passes through the dichroic mirror 46, is refracted by the objective lens 22, and illuminates the fundus oculi Ef. do.

The fundus reflected light of the observation illumination light is refracted by the objective lens 22, passes through the dichroic mirror 46, passes through a hole formed in the central region of the perforated mirror 21, passes through the dichroic mirror 55, and reaches the focusing lens. 31 and reflected by mirror 32 . Further, this fundus reflected light passes through the half mirror 39A, is reflected by the dichroic mirror 33 that selectively reflects near-infrared light, and is imaged on the light receiving surface of the CCD image sensor 35 by the condenser lens . The CCD image sensor 35 detects the fundus reflected light, for example, at a predetermined frame rate. The fundus image picked up by the CCD image sensor 35 is displayed on the display device 3, and this fundus image is observed by the examiner. The observation illumination light is near-infrared light, and the observation image captured by the CCD image sensor 35 is a near-infrared image.

When the imaging optical system is focused on the anterior segment, an observation image of the anterior segment of the eye E to be examined is captured by the CCD image sensor 35 and displayed on the display device 3 . Further, the display device 3 displays various kinds of information related to the operation of the ophthalmologic apparatus 1 and examination results. The ophthalmologic apparatus 1 also has a GUI (graphical user interface) using the display device 3 . The examiner operates the ophthalmologic apparatus 1 using this user interface.

The ophthalmologic apparatus 1 has a photographing light source 15 which is a light source for photographing the fundus. The imaging light source 15 is composed of, for example, a xenon lamp or an LED. The light (imaging illumination light) output from the imaging light source 15 irradiates the fundus oculi Ef through the same path as the observation illumination light. The fundus reflected light of the imaging illumination light is guided to the dichroic mirror 33 through the same path as that of the observation illumination light, passes through the dichroic mirror 33 that selectively reflects near-infrared light, and is reflected by the mirror 36, An image is formed on the light receiving surface of the CCD image sensor 38 by the condenser lens 37 .

An image based on the fundus reflected light detected by the CCD image sensor 38 is recorded as a fundus photographed image. This fundus captured image is an image in the visible light band. The display device 3 also displays a photographed fundus image detected by the CCD image sensor 38 . The display device 3 can switch between display of an observed image and display of a photographed image, or can simultaneously display both on a split screen. The form of this display can be selected by the operator of the ophthalmologic apparatus 1 .

An LCD (Liquid Crystal Display) 39 displays a fixation target and an index for visual acuity measurement, and irradiates the eye E with white light for contracting the iris of the eye E to be examined toward the center and reducing the pupil diameter. Acts as a light source. When the subject's eye E visually recognizes strong visible light, the iris contracts toward the center of the pupil in order to suppress the amount of light reaching the retina, and the pupil becomes smaller. This is a common human reaction. Using this principle, the diameter of the pupil of the subject's eye E is reduced by making the subject's eye E visually recognize white light. The LCD 39 is used as a light source for this purpose.

The fixation target is an index for fixing the eye E to be examined, and is used during fundus photography, OCTA measurement, and the like. In this example, the LCD 39 displays a display screen that displays an image of a specific color that serves as a fixation target on a white background screen that serves as the source of the white light. As the image forming the fixation target, a figure, a character, a design of an object, or the like having an easily visible shape is used. As the color of the fixation target, a color (for example, green, blue, etc.) that stands out from the white background and is easy to see is selected.

A configuration in which the LCD 39 is of a transmissive type and projects white light from behind, or a configuration in which a small LCD 39 is used and a white light source is arranged around the LCD is also possible. The light for contracting the iris of the subject's eye E and reducing the diameter of the pupil is light including a wavelength in a visible light band that is wider than light in a specific wavelength band (light of a specific color), that is, white light. preferable. Of course, the use of light of a specific wavelength is not excluded.

As a configuration that does not use the LCD 39 for the purpose of reducing the pupil diameter of the eye E to be inspected, there is a form in which the eye to be inspected E is irradiated with white illumination light from a light source arranged around the objective lens 22, or the light from the imaging optical system 30 is used. A form in which a white light source is inserted somewhere on the axis is exemplified.

A part of the light output from the LCD 39 is reflected by the half mirror 39A, reflected by the mirror 32, passes through the focusing lens 31 and the dichroic mirror 55, passes through the aperture of the apertured mirror 21, and is dichroic. The light passes through the mirror 46 and irradiates the subject's eye E through the objective lens 22 . By changing the display position of the fixation target on the screen of the LCD 39, the fixation position (line-of-sight direction) of the subject's eye E can be changed.

Further, the retinal camera unit 2 is provided with an alignment optical system 50 and a focus optical system 60, like a conventional retinal camera. The alignment optical system 50 generates an index (alignment index) using near-infrared light for aligning the device optical system with the eye E to be examined. The focus optical system 60 generates an index (split index) for focusing on the fundus oculi Ef.

Near-infrared light (alignment light) output from the LED 51 of the alignment optical system 50 passes through the apertures 52 and 53 and the relay lens 54, is reflected by the dichroic mirror 55, and passes through the perforated mirror 21. , passes through the dichroic mirror 46 and is projected onto the cornea of the subject's eye E by the objective lens 22 .

The cornea-reflected light of the alignment light passes through the objective lens 22 , the dichroic mirror 46 and the hole, and part of it passes through the dichroic mirror 55 . The dichroic mirror 55 basically reflects the near-infrared light output from the LED 51, but partially transmits it. Therefore, part of the reflected light of the alignment light from the subject's eye E is transmitted through the dichroic mirror 55 . This transmitted light passes through the focusing lens 31, is reflected by the mirror 32, passes through the half mirror 39A, is reflected by the dichroic mirror 33, and is projected onto the light receiving surface of the CCD image sensor 35 by the condenser lens . A received image (alignment index) by the CCD image sensor 35 is displayed on the display device 3 together with the observed image. The user carries out alignment by performing operations similar to those of a conventional fundus camera. Alternatively, the arithmetic and control unit 200 may analyze the position of the alignment index and move the optical system to perform alignment (auto-alignment function).

When performing focus adjustment, the reflecting surface of the reflecting bar 67 is moved onto the optical path of the illumination optical system 10 . In this case, the light (focus light) output from the LED 61 of the focus optical system 60 passes through the relay lens 62, is split into two light beams by the split indicator plate 63, passes through the two-hole diaphragm 64, and reaches the mirror 65. The light is reflected, once imaged on the reflecting surface of the reflecting bar 67 by the condensing lens 66, and then reflected. Further, the focused light passes through the relay lens 20, is reflected by the perforated mirror 21, passes through the dichroic mirror 46, is refracted by the objective lens 22, and is projected onto the fundus oculi Ef.

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

The dichroic mirror 46 branches the optical path for OCTA measurement from the optical path for fundus imaging. The dichroic mirror 46 reflects light in the wavelength band used for OCTA measurement and OCT measurement, and transmits light for fundus imaging. The optical path for OCTA measurement (which also serves as the optical path for OCT measurement) includes, in order from the OCTA unit 100 side, a collimator lens unit 40, an optical path length changing unit 41, a galvanometer scanner 42, a focusing lens 43, a mirror 44, and a relay. A lens 45 is arranged.

The collimator lens unit 40 converts the OCTA measurement light output from the OCTA unit 100 into a parallel light beam. The optical path length changing unit 41 is movable in the direction of the arrow shown in FIG. 1, and changes the optical path length of the optical path for OCTA measurement. This change in the optical path length is used for correction of the optical path length according to the axial length of the eye E to be examined, adjustment of the interference state, and the like. The optical path length changing unit 41 includes, for example, a corner cube and a mechanism for moving it.

The galvanometer scanner 42 changes the traveling direction of light (measurement light LS) passing through the optical path for OCTA measurement. Thereby, the fundus oculi Ef can be scanned (operated) with the measurement light LS. The galvanometer scanner 42 includes, for example, a galvanometer mirror that scans the measurement light LS in the x direction, a galvanometer mirror that scans in the y direction, and a mechanism for independently driving these. Thereby, the measurement light LS can be scanned in any direction on the xy plane. The OCTA scan is performed multiple times (for example, four times) at the same location with a time lag.

(OCTA unit)
An example of the configuration of the OCTA unit 100 will be described with reference to FIG. The OCTA unit 100 is provided with an optical system for acquiring an OCTA image of the fundus oculi Ef or the anterior segment. This optical system has a configuration similar to that of a conventional spectral domain type OCT apparatus. That is, this optical system divides the low-coherence light into reference light and measurement light, and generates interference light by causing interference between the measurement light that has passed through the fundus oculi Ef or the anterior segment and the reference light that has passed through the reference optical path. , is configured to detect spectral components of this interfering light. This detection result (detection signal) is sent to the arithmetic control unit 200 .

The configuration of the optical system of the OCTA unit 100 is the same as that of normal OCT, and the OCTA unit 100 can also create OCT images of the fundus and anterior segment of the eye.

In the case of a swept source type OCT apparatus, a wavelength swept light source is provided instead of a light source that outputs a low coherence light source, and an optical member for spectrally resolving interference light is not provided. In general, for the configuration of the OCTA unit 100, any known technique can be applied according to the type of optical coherence tomography.

The light source unit 101 outputs broadband low-coherence light L0. The low-coherence light L0 includes, for example, a wavelength band in the near-infrared region and has a temporal coherence length of about several tens of micrometers. Note that near-infrared light having a wavelength band invisible to the human eye, for example, a center wavelength of about 1040 to 1060 nm may be used as the low coherence light L0. Here, the low coherence light L0 including the wavelength reflected by the dichroic mirror 46 is used.

Fourier-domain OCT (eg, swept-source OCT) can be used to measure the fundus of an in-vivo eye. The type of OCT applicable to embodiments is not limited to swept source OCT, but may be spectral domain OCT or time domain OCT, for example. Further, the application target of OCT is not limited to the fundus, and may be the anterior ocular segment or the vitreous body.

The OCT unit 100 is provided with an optical system for applying swept-source OCT. This optical system includes interference optics. This interference optical system divides light from a wavelength tunable light source (wavelength swept light source) into measurement light and reference light, and superimposes the return light of the measurement light from the subject's eye E and the reference light that has passed through the reference light path. Interference light is generated together and the interference light is detected. A detection result (detection signal) obtained by the interference optical system is a signal representing the spectrum of the interference light, and is sent to the arithmetic control unit 200 .

Since the light used by the OCTA unit 100 must be separated from the light used in the illumination optical system 10 and the imaging optical system 30 by the dichroic mirror 46, the light used in the illumination optical system 10 and the imaging optical system 30 has a different wavelength. Use light containing The light source unit 101 uses a light output device such as a Super Luminescent Diode (SLD), an LED, or an SOA (Semiconductor Optical Amplifier). A low-coherence light L0 output from the light source unit 101 is guided to the fiber coupler 103 by the optical fiber 102 and split into the measurement light LS and the reference light LR.

The reference light LR is guided by an optical fiber 104 and reaches an optical attenuator 105 . The optical attenuator 105 automatically adjusts the light amount of the reference light LR guided to the optical fiber 104 under the control of the arithmetic control unit 200 using a known technique. The reference light LR whose light amount has been adjusted by the optical attenuator 105 is guided by the optical fiber 104 and reaches the polarization adjuster (polarization controller) 106 . The polarization adjuster 106 adjusts the polarization state of the reference light LR guided through the optical fiber 104 by, for example, externally applying stress to the looped optical fiber 104 . Note that the configuration of the polarization adjuster 106 is not limited to this, and any known technique can be used. The reference light LR whose polarization state has been adjusted by the polarization adjuster 106 reaches the fiber coupler 109 .

The measurement light LS generated by the fiber coupler 103 is guided by the optical fiber 107 and made into a parallel light beam by the collimator lens unit 40 . Furthermore, the measurement light LS reaches the dichroic mirror 46 via the optical path length changing section 41 , the galvanometer scanner 42 , the focusing lens 43 , the mirror 44 and the relay lens 45 . Then, the measurement light LS is reflected by the dichroic mirror 46, refracted by the objective lens 22, and irradiated to the fundus oculi Ef or the anterior segment of the eye. The measurement light LS is scattered (including reflected) at various depth positions in the fundus oculi Ef or the anterior segment. Backscattered light (return light) of the measurement light LS due to the fundus oculi Ef or the anterior segment of the eye travels in the opposite direction along the same path as the outward path, is guided to the fiber coupler 103, and reaches the fiber coupler 109 via the optical fiber 108. do.

The fiber coupler 109 causes interference between the backscattered light of the measurement light LS and the reference light LR that has passed through the optical fiber 104 . The interference light LC thus generated is guided by the optical fiber 110 and emitted from the emission end 111 . The interference light LC emitted from the output end 111 is collimated by a collimator lens 112, dispersed (spectrally resolved) by a diffraction grating 113, condensed by a condensing lens 114, and projected onto a light receiving surface of a CCD image sensor 115. be done. Although the diffraction grating 113 shown in FIG. 2 is of a transmissive type, it is also possible to use other types of spectral elements such as a reflective diffraction grating.

The CCD image sensor 115 is, for example, a line sensor, detects each spectral component of the scattered interference light LC, and converts it into an electric charge. The CCD image sensor 115 accumulates this charge to generate a detection signal and sends it to the arithmetic control unit 200 .

In OCTA, the same location is scanned multiple times. In this case, data for each scan is sent from the CCD image sensor 115 to the arithmetic control unit 200, which will be described later.

Although a Michelson type interferometer is employed in this embodiment, any type of interferometer such as a Mach-Zehnder type interferometer can be appropriately employed. Also, instead of the CCD image sensor, it is possible to use another type of image sensor, such as a CMOS image sensor.

(arithmetic control unit)
The arithmetic control unit 200 controls the ophthalmologic apparatus 1 and creates an OCTA image based on the interference light detected by the CCD image sensor 115 . The arithmetic and control unit 200 can also create OCT images of the fundus and anterior segment of the eye. Regarding this point, since it is the same as a normal OCT apparatus, the explanation is omitted.

The configuration of the arithmetic control unit 200 will be described below. The arithmetic control unit 200 has a function as a computer. Arithmetic control unit 200 includes electronic circuits such as a microprocessor, RAM, ROM, hard disk drive, communication interface, and the like, as in a conventional computer. The arithmetic control unit 200 may be composed of dedicated hardware, or part or all of it may be composed of a general-purpose PC (personal computer) or WS (workstation).

FIG. 3 shows a block diagram of the arithmetic control unit 200. As shown in FIG. The arithmetic control unit 200 includes an operation control unit 201, a visible light irradiation control unit 202, a pupil diameter measurement unit 203, an OCTA scan range setting unit 204, an OCTA scan control unit 205, an OCTA data acquisition unit 206, and an OCTA image creation unit 207. . These functional units may be configured by a dedicated electronic circuit (FPGA, etc.), or may be realized by software processing.

The operation control unit 201 controls the operation of each unit of the ophthalmologic apparatus 1 . A visible light irradiation control unit 202 adjusts the intensity of irradiation light for reducing the diameter of the pupil. In this example, the visible light irradiation control unit 202 adjusts the emission intensity of the white screen portion of the LCD 39 . This emission intensity adjustment is performed when the diameter of the pupil of the subject's eye E measured by the pupil diameter measuring unit 203, which will be described later, is equal to or less than a predetermined value, or a predetermined contraction rate or less (for example, 70% or less of the original diameter). It is done so that

FIG. 4A shows the state before the iris is contracted and the pupil diameter is reduced, and FIG. The state after the pupil diameter is reduced by contracting is shown.

A pupil diameter measurement unit 203 measures the diameter of the pupil reflected in the anterior segment image captured by the CCD image sensor 35 or 38 . The pupil diameter is measured by extracting image information of the pupil from the image and calculating the pupil diameter from the screen coordinates. For example, the actual diameter of the pupil of the subject's eye in the reference standard model and the number of pixels corresponding to the pupil diameter of the subject's eye in the screen obtained by counting the number of pixels in the captured image. Acquire the relationship in advance. Using this relationship, the diameter of the pupil of the subject's eye E is calculated from the anterior segment image of the subject's eye E captured by the CCD image sensor 35 or 38 during eye examination. This processing is performed by the pupil diameter measurement unit 203 .

An OCTA scan range setting unit 204 sets a scan range for obtaining an OCTA image of the anterior segment. What is important in blood vessel information in the anterior segment is the state of blood vessels near the boundary between the pupil and the iris. This is for the following reasons. Normally, there are no blood vessels in the pupil under normal conditions. However, in certain diseases and disorders in the anterior segment, blood vessels extend from the iris to the pupil, or vascular abnormalities occur near the boundary between the pupil and the iris. In this case, it is important for ophthalmologic examination to observe the condition of the blood vessels near the boundary between the pupil and the iris.

The OCTA scan range setting unit 204 sets the scan range so that the vicinity of the boundary between the pupil and the iris falls within the OCTA scan range. The processing for setting the scan range is performed as follows.

First, a circle inscribed in a rectangular scan range is set. The center of this circle is matched with the center of the pupil captured by the CCD image sensor 35 or 38 . Next, a search is made for the diameter of the circle in which the pupil does not protrude from the circle. Next, the diameter of the circle is enlarged so that the minimum value of the distance between the circle and the outer edge of the pupil becomes a specified value. Finally, a rectangular area circumscribing the circle is set as the scan range for OCTA. FIG. 4B shows an example of setting a scan range that satisfies the above conditions.

The OCTA scan control unit 205 controls the operation of the galvanometer scanner 42 so that the OCTA scan is performed within the scan range set by the OCTA scan range setting unit 204 .

The OCTA data acquisition unit 206 acquires data of interference light detected by the CCD image sensor 115 . In this embodiment, scanning is performed four times on the same location. The OCTA data acquisition unit 206 acquires the data of the interference light for these four scans.

The OCTA image creation unit 207 creates an OTCA image of the anterior segment (an image obtained by detecting the state of blood vessels) based on the data of the interference light acquired by the OCTA data acquisition unit 206 . A method for creating an OCTA image is performed using a known technique. The creation of OCTA images is described in, for example, Japanese Patent Application Laid-Open Nos. 2017-140302, 2017-6179, and 2016-202900.

(Example of operation)
An example of processing related to an ophthalmologic diagnosis using the ophthalmologic apparatus 1 will be described below. FIG. 5 is a flowchart showing an example of the procedure of processing. A program for executing the processing shown in FIG. It is also possible to store this program in an external storage medium, storage server, etc., and download it from there for use.

First, on the display screen of the display device 3, when the examiner who operates the ophthalmologic apparatus 1 selects the icon for imaging (step S101), a display for selecting whether or not the OCTA image of the anterior segment is to be photographed. A screen appears (step S102). Here, if imaging of an OCTA image of the anterior segment is selected, the process proceeds to step S104 and subsequent steps.

If imaging of an OCTA image of the anterior segment is not selected, the process proceeds to step S103. In step S103, processing related to photographing of the fundus is performed. Fundus photography includes fundus photography using a fundus camera, fundus OCT photography, fundus OCTA imaging, fundus angiography, and fundus photography using SLO. Since these processes are normal processes, description thereof will be omitted.

In step S104, notification regarding the presence or absence of fundus photography is performed. In this example, a message indicating whether or not the fundus has already been photographed is displayed on the display device 3, for example, "Has the fundus photographed already been completed?"

In addition, in a configuration that can determine whether or not the fundus of the subject has already been photographed on the arithmetic and control unit 200 side, if it is determined that the fundus of the subject has not been photographed at this time, the display A display prompting the device 3 to photograph the fundus is displayed. For example, the display device 3 displays a message such as "It seems that the fundus has not yet been photographed. Are you sure?"

Normally, the subject's identification code is managed in an electronic chart or the like, and whether or not fundus photography has already been performed on the day can be determined by the arithmetic control unit 200 side. Based on this determination, the above processing is performed.

The reason for performing the process of step S104 will be described below. As will be described later, in the processing after step S105, the iris of the subject's eye is contracted and the pupil is narrowed. By the way, the pupil that has become small at one end does not return to its original size for a while even if the visible light that causes the pupil to become smaller does not enter the eye to be inspected (of course, there are individual differences).

On the other hand, since fundus photography is performed through the pupil, problems arise when the pupil is small (it is well known that eyedrops are generally dripped to dilate the pupil during fundus photography). . Therefore, when fundus photography is required, it is preferable to complete the fundus photography before performing the processing from step S105 onward in order to improve the efficiency of the examination.

For the above reason, the process of step S104 is performed, and an examiner process is performed to display a message to the examiner on the display device 3 as to whether or not fundus imaging is to be performed. In this case, the display device 3 functions as a notification unit. In addition, it is also possible to proceed to step S103 at the stage of step S104.

A case where the process proceeds to step S105 and below will be described below. In step S105, the LCD 39 emits white light. That is, by irradiating the subject's eye E with strong visible light as stimulation light, the iris is contracted and the diameter of the pupil is reduced. At this time, since excessively strong light burdens the eye E to be examined, the emission intensity of the LCD 39 is adjusted in advance.

At the same time, the pupil diameter measurement value obtained in step S106, which will be described later, is fed back to determine whether the pupil diameter is equal to or less than a specific value, or whether the reduction rate of the pupil diameter (diameter after reduction/diameter before reduction) is equal to or less than a specific value. The emitted light intensity of the LCD 39 is adjusted so that This adjustment is performed by the visible light irradiation control section 202 of the arithmetic control unit 200 .

At the same time as the process of step S105, the pupil diameter is measured (step S106). This process is performed by the pupil diameter measurement section 203 of the arithmetic control unit 200 . Next, a scan range necessary for obtaining an OCTA image of the anterior segment is set (step S107). This processing is performed by the OTCA scan range setting unit 204 .

Next, the range set in step S107 is scanned (photographed) to obtain OCTA data (step S108). Control related to this processing is performed by the OCTA scan control unit 205 . After obtaining the OCTA data, an OCTA image of the anterior segment is created based on the data.

(Other embodiments)
In step S105, it is also possible to irradiate the eye other than the subject's eye with white light. As a reaction of the human body, when only one of the eyes is exposed to strong light, the pupil of the other eye, to which the light is not incident, also shrinks. Using this phenomenon, it is possible to irradiate the eye other than the eye to be inspected with white light to contract the pupil of the eye to be inspected, and perform the processing from step S105 onward.

In this case, the ophthalmologic apparatus 1 is equipped with a light source for applying white light to the other eye of the subject. The control of this light source is performed by the visible light irradiation control 202 of the arithmetic control unit 200 .

This configuration can be applied to conventional models capable of OCTA imaging of the anterior segment. That is, a conventional ophthalmologic apparatus capable of OCTA imaging of the anterior segment is additionally equipped with a light source for irradiating the eye other than the subject's eye with white light using an adapter or the like, and the processing of FIG. 5 is further performed. Install a new control program for As a result, an ophthalmologic apparatus having the same functions as the ophthalmologic apparatus 1 of FIG. 1 and capable of performing the processing of FIG. 5 is obtained.

(Superiority)
When acquiring an OCTA image of the anterior segment, the eye to be examined is irradiated with visible light in order to narrow the scan range. As a result, the iris of the eye to be examined contracts and the pupil becomes smaller. Since the target position of anterior segment OCTA is near the boundary between the pupil and the iris, the range of scanning required for anterior segment OCTA can be narrowed by making the pupil smaller. By narrowing the scanning range, it is possible to shorten the time required for the scanning required to acquire the anterior segment OCTA image, and reduce the burden on the subject. In addition, the efficiency of ophthalmologic examination can be enhanced.

DESCRIPTION OF SYMBOLS 1... Ophthalmic apparatus, 2... Fundus camera unit, 3... Display apparatus, 10... Illumination optical system, 11... Observation illumination light source, 12... Reflecting mirror, 13... Condensing lens, 14... Visible cut filter, 15... Imaging light source, DESCRIPTION OF SYMBOLS 16... Mirror 17, 18, 20... Relay lens 19... Diaphragm 21... Hole mirror 22... Objective lens 30... Optical system 31... Focusing lens 32... Mirror 33... Dichroic mirror 34... Condenser lens 35 CCD image sensor 36 mirror 37 condenser lens 38 CCD image sensor 39 LCD 39A half mirror 40 collimator lens unit 41 optical path length changing unit 42 Galvanometer scanner 43 Focusing lens 44 Mirror 45 Relay lens 46 Dichroic mirror 50 Alignment optical system 55 Dichroic mirror 60 Focusing optical system 100 OCTA unit 101 Light source unit DESCRIPTION OF SYMBOLS 102... Optical fiber, 103... Fiber coupler, 104... Optical fiber, 105... Optical attenuator, 106... Polarization adjuster, 107, 108... Optical fiber, 109... Fiber coupler, 111... Output end, 112... Collimator lens, 113... Diffraction grating, 114... Condensing lens, 115... CCD image sensor.

Claims (6)

an OCT angiography data acquisition unit that acquires OCT angiography data of the anterior segment of the subject's eye;
a visible light irradiation unit that irradiates the eye to be inspected with visible light when acquiring data for the OCT angiography;
a notifying unit that notifies whether or not fundus imaging is performed at a stage prior to the irradiation of the visible light;
An ophthalmic device comprising: an OCT angiography data acquisition unit that acquires OCT angiography data of the anterior segment of the subject's eye;
and an ophthalmologic apparatus comprising : a visible light irradiating unit that irradiates visible light to the other eye of the subject that is not the eye to be examined when acquiring the data of the OCT angiography. irradiating an eye to be inspected with visible light to reduce the pupil of the eye to be inspected;
acquiring OCT angiography data of the anterior segment of the eye to be inspected with the pupil constricted;
a step of notifying whether or not fundus imaging of the eye to be examined has been performed in a stage prior to the irradiation of the visible light;
An ophthalmic measurement method comprising: A step of irradiating the other eye of the subject, which is not the eye to be examined, with visible light to reduce the pupil of the eye to be examined;
and acquiring OCT angiographic data of the anterior segment of the subject's eye with the pupil constricted. A program that is read and executed by a computer,
to the computer
irradiating an eye to be inspected with visible light to reduce the pupil of the eye to be inspected;
acquiring OCT angiography data of the anterior segment of the eye to be inspected with the constriction of the pupil;
a step of notifying whether or not fundus imaging of the eye to be examined has been performed in a stage prior to the irradiation of the visible light;
program to run. A program that is read and executed by a computer,
to the computer
A step of irradiating the other eye of the subject, which is not the eye to be examined, with visible light to reduce the pupil of the eye to be examined;
acquiring OCT angiography data of the anterior segment of the eye to be inspected with the pupil constricted.

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