JP2023019698A - Ophthalmologic examination device and control method of ophthalmologic examination device - Google Patents

Abstract

To improve the quality of a tomographic image of the anterior eye part.SOLUTION: An ophthalmologic examination device for acquiring a tomographic image of the anterior eye part using interference light obtained by combining return light from the anterior eye part of an eye to be examined irradiated with measurement light with reference light includes: scanning means for scanning the measurement light in the anterior eye part; driving means for driving focusing means for adjusting a focusing position of the measurement light; and control means for controlling the driving means so that the focusing position of the measurement light is farther from the ophthalmologic examination device than a focusing position set in a first mode when a second mode is selected out of a plurality of modes including the first mode in which a first swing angle is set as a swing angle for scanning the measurement light and the second mode in which a second swing angle larger than the first swing angle is set.SELECTED DRAWING: Figure 7

Description

The technology disclosed in this specification relates to an ophthalmic examination apparatus and a control method for the ophthalmic examination apparatus.

An ophthalmologic examination apparatus (hereinafter referred to as an OCT apparatus) using optical coherence tomography (hereinafter referred to as OCT) is known as an apparatus for obtaining a tomographic image of an eye to be examined.

An OCT apparatus for ophthalmologic examination irradiates an eye to be inspected with measurement light, which is low coherent light, and combines the return light from the eye to be inspected with the reference light to obtain interference light. By analyzing the frequency components of the spectrum of the interference light, information about the layer structure of the eye to be examined can be obtained, and a tomographic image of the eye to be examined can be obtained. For example, when an OCT apparatus is used for fundus examination, it is possible to obtain a tomographic image at a desired depth of the fundus of the subject's eye by adjusting the optical path length difference between the measurement light and the reference light.

In addition, the OCT apparatus can obtain a tomographic image of not only the fundus of the subject's eye but also the anterior segment of the eye. By inserting/removing a predetermined lens (adapter lens) into/from the optical path of the measuring light inside or outside the OCT apparatus, it is possible to switch the imaging region for acquiring the tomographic image between the fundus and the anterior segment of the eye. By using the adapter lens, the optical system used for acquiring the tomographic image of the fundus can be shared with the optical system used for acquiring the tomographic image of the anterior segment, and the apparatus can be made compact.

Patent Document 1 discloses a technique of acquiring a tomographic image of the anterior segment of the eye by focusing the measurement light on the anterior segment of the subject's eye using an optical system in which an adapter lens is inserted in the optical path of the measurement light. disclosed.

JP 2018-23675 A

Here, Patent Document 1 discloses focusing on the corneal vertex. When the measurement light is focused on the apex of the cornea when photographing the anterior segment with a wide angle of view, the entire cornea within the angle of view can be photographed because the cornea is curved in a direction away from the ophthalmologic examination apparatus. In some cases, it was difficult to enter the allowable depth range. Therefore, when the anterior segment is imaged with a wider angle of view than the conventional one, the amount of light in the peripheral part of the cornea is insufficient compared to the apex of the cornea, and the quality of the tomographic image may be degraded.

One of the disclosed technologies aims to improve the quality of a tomographic image of the anterior segment.

In addition to the above object, it is also another object of the present invention to achieve an effect derived from each configuration shown in the mode for carrying out the invention described later, and an effect that cannot be obtained by the conventional technology. can be positioned as one.

One of the disclosed techniques is
An ophthalmologic examination apparatus for acquiring a tomographic image of the anterior segment of the eye using interference light obtained by combining reference light and return light from the anterior segment of an eye to be examined irradiated with measurement light,
scanning means for scanning the measurement light in the anterior segment;
driving means for driving focusing means for adjusting the focus position of the measurement light;
A plurality of modes including a first mode in which a first swing angle is set as a swing angle for scanning the measurement light and a second mode in which a second swing angle larger than the first swing angle is set When the second mode is selected from among the modes, the driving means is controlled so that the focus position of the measurement light becomes farther from the ophthalmologic examination apparatus than the focus position set in the first mode. a control means;
Prepare.

According to one of the disclosed techniques, it is possible to improve the quality of a tomographic image of the anterior segment.

1 is a diagram showing a schematic configuration of an optical system in Example 1. FIG. 4 shows a schematic configuration example of a control unit in Examples 1 and 2. FIG. FIG. 4 is a diagram for explaining scanning of an eye to be inspected in the x direction; FIG. 10 is a diagram for explaining the optical path of measurement light when the adapter lens is not inserted in Example 1; FIG. 10 is a diagram for explaining the optical path of measurement light when the adapter lens is inserted in Example 1; FIG. 4 is a diagram for explaining a configuration for acquiring a tomographic image of the anterior segment with a narrow angle of view; FIG. 4 is a diagram for explaining a configuration for acquiring a tomographic image of the anterior segment with a wide angle of view; FIG. 4 is a diagram for explaining a difference in NA (numerical aperture) when acquiring a tomographic image with a wide angle of view; FIG. 4 is a diagram for explaining screen transition; It is a figure for demonstrating a patient screen. It is a figure for demonstrating the OCT imaging screen. It is a figure for demonstrating a report screen. It is a figure for demonstrating a report screen. It is a figure for demonstrating a report screen. It is a figure for demonstrating a report screen. It is a figure for demonstrating a report screen. It is a figure for demonstrating a report screen. FIG. 10 is a diagram for explaining a configuration for acquiring a tomographic image of the anterior segment in Example 2;

An embodiment will be described below with reference to the drawings. The same or equivalent constituent elements, members, and processes shown in each drawing are denoted by the same reference numerals, and duplication of description will be omitted as appropriate. In addition, in each drawing, some components, members, and processes that are not important for explanation may be omitted.

<Example 1>
In this embodiment, an example of acquiring a tomographic image of the anterior segment with an angle of view wider than that of a conventional one using an OCT apparatus in which an adapter lens is inserted will be described. One of the ophthalmologic examination apparatuses disclosed in this embodiment improves the quality of tomographic images by presetting a focus position according to the angle of view and adjusting the focus position in accordance with an instruction to select the angle of view. can do.

In addition, usability is improved by making it possible to select a desired photographing from the narrow angle of view photographing in the first mode and the wide angle of view photographing in the second mode.

In the present embodiment, imaging in which the range for acquiring an image in the anterior segment is circular and the diameter of the circle is 6 mm as the first mode, and imaging in which the diameter of the circle is 9 mm will be described as the second mode. However, it is not limited to these angles of view. Other angles of view may be set in advance, and three or more angles of view may be set. For example, it may be possible to set an angle of view of 7 mm as the third mode.

Further, in the technology disclosed in this specification, the swing angle of the measurement light is set in advance according to the angle of view. That is, the swing angle of the measurement light is set for each of the first mode and the second mode, and the swing angle of the second mode is larger than the swing angle of the first mode.

(Schematic configuration of the device)
A schematic configuration of an ophthalmologic examination apparatus according to this embodiment will be described with reference to FIGS. 1 and 2. FIG.

FIG. 1 is a schematic diagram showing a schematic configuration of an optical system in an ophthalmologic apparatus according to Example 1. FIG. As shown in the figure, the optical system has an optical head 900 and a spectroscope 180 . The optical head 900 is configured as a measurement optical system for capturing a tomographic image of the anterior segment of the subject's eye 100 and the fundus. In addition, an adapter lens 105 is detachably attached to the optical head 900 as imaging region switching means for switching the imaging region between the fundus and the anterior segment of the eye.

Note that the dispersion of the adapter lens is adjusted to be substantially equal to the dispersion from the anterior segment of the eye 100 to be examined to the fundus so that the dispersion of the optical system does not change when the adapter lens is inserted or removed. A detailed description of the dispersion will be given later.

FIG. 2 is a diagram showing a schematic configuration of a control unit in the ophthalmologic apparatus according to Examples 1 and 2. FIG. The control unit 300 is configured to be connectable with the optical head 900 and the spectroscope 180 . The control unit 300 controls the optical head 900 and the spectroscope 180 to photograph the subject's eye. The control unit 300 is provided with an imaging control unit 301 , a storage unit 302 , an image acquisition unit 304 and an image processing unit 305 .

(Optical system of optical head and spectroscope)
The configuration of the optical system and the spectrometer according to this embodiment will be described with reference to FIG.

First, the internal configuration of the optical head 900 will be described. Inside the optical head 900, a first dichroic mirror 102, a second dichroic mirror 103, and a third dichroic mirror 104 are arranged as optical path separating means. An objective lens 101-1 is placed facing the eye 100 to be inspected, and a first dichroic mirror 102 is arranged on the optical axis of the reflected light from the eye 100 to be inspected.

A second dichroic mirror 103 is arranged on the optical axis of the reflected light of the first dichroic mirror 102 . That is, the optical axis of the transmitted light of the second dichroic mirror is divided into the measurement optical path L1 of the OCT optical system, and the optical axis of the reflected light is divided into the two-dimensional observation optical path and the fixation lamp optical path L2 for each wavelength band. Further, the optical axis of the light transmitted through the first dichroic mirror 102 is split for each wavelength band so that the optical axis of the light is on the anterior eye observation optical path L3. The third dichroic mirror 104 is used to further split the two-dimensional observation optical path and the fixation lamp optical path L2 for each wavelength band, as will be described later.

An X scanner and a Y scanner, which are scanning means to be described later, are arranged in the two-dimensional observation optical path and the fixation lamp optical path L2. The two-dimensional observation optical path and the fixation lamp optical path L2 are arranged so that a two-dimensional image of the fundus can be obtained by scanning the fundus of the subject's eye 100 with illumination light when the adapter lens 105 is not inserted in the optical path. Configured. When the adapter lens 105 is inserted in the optical path, a two-dimensional image of the anterior segment of the eye 100 to be examined is obtained by scanning the anterior segment of the eye 100 to be examined with illumination light using the X scanner and the Y scanner. can be done.

Further, the third dichroic mirror 104 splits the light into an optical path leading to the light source 114 for two-dimensional observation and an optical path leading to the fixation lamp 119 for each wavelength band. In order from the second dichroic mirror 103, the two-dimensional observation optical path and the fixation lamp optical path L2 include a lens 101-2, an X scanner 117-1, a Y scanner 117-2, a focusing lens 112, an optical path separating member 118, and a lens. 113-1, and a third dichroic mirror 104 are arranged.

The light source 114 generates light with a wavelength of 780 nm, for example. The focusing lens 112 is driven in the optical axis direction (arrow direction in the drawing) by a motor (not shown) for focus adjustment of the fixation lamp 119 , the single detector 116 for two-dimensional observation, and the light source 114 . The fixation lamp 119 is used to prompt fixation of the subject's eye 100 in an arbitrary direction, and is composed of, for example, a laser or an LED (Light Emitting Diode) that emits light in the visible range.

The X scanner 117-1 and Y scanner 117-2 are scanning means used to scan the fundus or anterior segment of the subject's eye 100 with illumination light emitted from the light source 114. FIG. The lens 101-2 is arranged with the focal position near the center position of the X scanner 117-1 and Y scanner 117-2.

The X scanner 117-1 is composed of a polygon mirror in order to scan the illumination light in the x direction at high speed. Alternatively, the X scanner 117-1 may be composed of a resonant mirror. The optical path between the X scanner 117-2, pinhole 115, light source 114, and fixation lamp 119, which will be described later, is configured within the plane of the paper, but is actually configured in the direction perpendicular to the plane of the paper. In the case of increasing the size in the direction perpendicular to the plane of the drawing, the optical path may be bent by a mirror (not shown).

A lens 113 - 2 , a pinhole 115 and a single detector 116 are arranged on the optical path of the reflected light of the optical path separating member 118 . When the adapter lens 105 is not inserted, the pinhole 115 is placed at a substantially conjugate position with the fundus of the eye 100 to be examined, and the pinhole 115 placed at a conjugate position with the fundus constitutes a confocal optical system. ing. When the adapter lens 105 is inserted, the pinhole 115 is placed at a substantially conjugate position with the anterior segment of the eye 100 to be examined, and the pinhole 115 placed at a conjugate position with the anterior segment of the eye 100 forms a confocal optical axis. constitutes the system.

The illumination light from the light source 114 that scans the fundus or the anterior segment is scattered and reflected by the fundus or the anterior segment. The pinhole 115 allows only the necessary light to pass through the scattered/reflected light, and the single detector 116 receives the light. The single detector 116 is composed of an APD (avalanche photodiode). The optical path separating member 118 is a prism in which a perforated mirror or a hollow mirror is vapor-deposited, and separates the illumination light from the light source 114 and the return light from the fundus.

A lens 141 and a CCD 142 for anterior eye observation are arranged in order from the first dichroic mirror on the anterior eye observation optical path L3. This CCD 142 has a sensitivity around 970 nm, which is the wavelength of illumination light for anterior eye observation (not shown).

The measurement optical path L1 constitutes an OCT optical system as described above, and is used to capture a tomographic image of the fundus of the subject's eye 100 when the adapter lens 105 is not inserted. When the adapter lens 105 is inserted, a tomographic image of the anterior segment of the eye 100 to be examined is captured. More specifically, it obtains an interference signal for forming a tomographic image.

The measurement optical path L1 includes, in order from the second dichroic mirror 103, a lens 101-3, a mirror 121, an OCTX scanner 122-1, an OCTY scanner 122-2, an OCT focusing lens 123, an OCT detachable lens 127, and a lens 124. and fiber end 126 are positioned. These optical members constitute a part of an optical system for irradiating an eye to be examined with OCT measurement light, which will be described later.

The OCT focusing lens 123 is an example of focusing means and is driven by a motor (not shown), which is an example of driving means. Note that the focusing means may be a mirror instead of a lens. Further, the driving of the focusing means may include driving a lens whose focal position can be changed by electrical control, which will be described later.

An OCTX scanner 122-1 and an OCTY scanner 122-2, which are measuring light scanning means, are arranged to scan the fundus or the anterior segment of the eye 100 to be inspected with the measuring light.

The fiber end 126 is an example of a light source for measurement light and directs the measurement light into the measurement light path. When the adapter lens 105 is not inserted, the fiber end 126 is optically conjugate with the fundus of the subject's eye 100 in this embodiment. When the adapter lens 105 is inserted, the fiber end 126 is optically conjugate with the anterior segment of the eye 100 to be examined.

The OCT focusing lens 123 is driven in the optical axis direction (arrow direction in the drawing) by a motor (not shown) in order to focus the measurement light on the fundus or the anterior segment of the eye. The OCT focusing lens 123 functions as a lens that focuses measurement light onto the eye 100 to be examined. Focus adjustment is performed so that the light emitted from the fiber end 126, which is the measurement light source, forms an image on the fundus or the anterior segment of the eye.

However, when acquiring a tomographic image of the anterior segment, the OCT focusing lens 123 is fixed at a predetermined position as described later. A position determined according to a range (angle of view) for acquiring an image is stored in advance in the device. Although the optical path between the X scanner 122-1 and the Y scanner 122-2 is configured within the plane of the paper, it may be configured in the direction perpendicular to the plane of the paper.

Next, the configuration of the optical path from the light source 130 to the fiber end 126, the reference optical system, and the spectroscope will be described. Light emitted from the light source 130 reaches the optical coupler 125 through the optical fiber 125-1. Single-mode optical fibers 125 - 1 to 4 are connected to optical coupler 125 . The light that has reached the optical coupler 125 is divided into measurement light and reference light here. be killed.

The optical coupler 125 constitutes a light splitter that splits the light emitted from the light source 130 into measurement light and reference light. The exit end of the optical fiber 125-2 reaches the fiber end 126 described above. The measurement light passes through the optical path of the OCT optical system described above, is irradiated to the fundus or the anterior segment of the eye 100 to be observed, and reaches the optical coupler 125 through the same optical path due to reflection and scattering by the retina.

In the reference optical system, a lens 151, a dispersion compensating glass 152, and a mirror 153 are arranged in order from the exit end of the optical fiber 125-3. These configurations, including the spectroscope 180 described later, constitute a Michelson interferometer. The spectroscope 180 constitutes a detector that receives interference light between the return light from the eye 100 to be inspected and the reference light. A mirror 153 changes the optical path length difference between the reference light and the measurement light.

The reference light emitted from the exit end of the optical fiber 125-3 reaches the mirror 153 via the lens 151 and the dispersion compensating glass 152 and is reflected. A dispersion compensating glass 152 is inserted in the optical path to match the dispersion of the measurement light and the reference light. The reference light reflected by the mirror 153 returns to the optical coupler 125 along the same optical path. A mirror 153 changes the optical path length of the reference light. Further, since the dispersion of the adapter lens is substantially equal to the dispersion from the anterior segment of the eye 100 to the fundus, there is no need to additionally insert or remove the dispersion compensating glass in the reference optical path.

The optical coupler 125 multiplexes the measurement light, which is the return light from the eye 100 to be examined, and the reference light reflected from the mirror 153 to produce interference light. Here, interference occurs when the optical path length of the return light and the optical path length of the reference light are substantially the same. The mirror 153 is held so as to be adjustable in the optical axis direction by a motor and drive mechanism (not shown) controlled by a mirror control system (not shown). This allows the mirror 153 to match the optical path length of the reference light with the optical path length of the return light that varies depending on the eye 100 to be examined. The interference light is guided to spectroscope 180 via optical fiber 125-4.

The spectroscope 180 comprises lenses 181 and 183, a diffraction grating 182 and a line sensor 184. FIG. After the interference light emitted from the optical fiber 125-4 becomes substantially parallel light through the lens 181, it is dispersed by the diffraction grating 182 and formed into an image on the line sensor 184 by the lens 183. FIG. Information about the luminance distribution in the interference signal acquired by the line sensor 184, which is a detector, is output as an output signal to the image acquisition unit, and constructed and acquired as a tomographic image in the image acquisition unit.

Next, the periphery of the light source 130 will be described. The light source 130 is an SLD (Super Luminescent Diode) which is a typical low coherent light source. The central wavelength is, for example, 855 nm, and the wavelength bandwidth is, for example, approximately 100 nm. Here, the bandwidth is an important parameter because it affects the resolution of the obtained tomographic image in the optical axis direction.

Also, SLD was selected as the type of light source, but it is sufficient if low coherence light can be emitted. Near-infrared light is suitable for the central wavelength, considering that the eye is to be measured. Also, if the NA (numerical aperture) is the same, the central wavelength affects the lateral resolution of the obtained tomographic image, so it is desirable that the wavelength be as short as possible. For both reasons, the center wavelength was set to 855 nm in this example.

In this embodiment, a Michelson interferometer is used as an interferometer, but a Mach-Zehnder interferometer may be used. Also, an example of the configuration of OCT using an SLD and a spectroscope, that is, the so-called SD-OCT, has been shown, but an SS-OCT configuration using a wavelength-swept light source may also be used.

Operations such as the operation of the scanner and the like in the optical head 900 described above, the lighting control of the fixation lamp 119, the imaging of an image, and the construction of an image based on the intensity information acquired from the OCT optical system are controlled by the imaging control unit 301, which will be described later. executed. Further, the insertion and removal of the adapter lens 105 to and from the optical path, which will be described later, may be performed by an operator, or may be performed via a drive mechanism (not shown).

(Function of adapter lens)
In this embodiment, an example will be described in which an insertable/removable adapter lens 105 is inserted between the objective lens 101-1 and the eye 100 to be examined in order to switch the imaging region from the fundus of the eye 100 to the anterior segment. Note that the adapter lens may be configured to be inserted between the X scanner 122-1 and the eye 100 to be examined. In this embodiment, the adapter lens 105 is inserted in the vicinity of the eye 100 to be inspected due to ease of construction, etc., but it is possible to insert it in the above-described position on the measurement optical path L1.

As for the insertion of the adapter lens 105 into the optical path, it is possible to attach it manually or the like, detect this by the imaging control unit 301, and cause the apparatus to execute corresponding control. Further, an inserting means for performing an inserting operation may be provided, and the inserting means may be caused to insert the adapter lens in response to an instruction to switch the imaging region received by the imaging control unit 301 .

Considering that the conjugate position of the fiber end 126 is switched from the fundus of the eye 100 to the anterior segment by inserting the adapter lens 105, the adapter lens 105 is preferably a lens with positive power. For example, adapter lens 105 may be a lens such as a convex lens or a positive meniscus lens.

The thickness of the adapter lens 105 is determined by considering the group velocity GD when light passes from the anterior segment of the eye 100 to the fundus. The group velocity GD is represented by the following formula.
GD=dng/dλ=-λ×d2n/dλ2 (Formula 1)

where ng=n−λ×dn/dλ, where λ is the center wavelength of the light source 130, dng/dλ is the wavelength derivative of the group refractive index ng, and d2n/dλ2 is the second derivative of the wavelength of the refractive index n. , dn/dλ indicates the wavelength derivative of the refractive index.

That is, the group velocity GD of the medium in the eye 100 to be examined is obtained, and the product (GD×L) of the thickness L of the medium in the eye 100 to be examined and the thickness L in the optical axis direction of the eye 100 to be examined and the adapter lens 105 substantially match. By configuring as above, the glass material and thickness of the adapter lens 105 are determined. This cancels the dispersion of light generated in the optical system, making it possible to obtain a clear tomographic image without blurring. Further, there is no need to adjust dispersion accompanying switching between photographing between the fundus and the anterior segment, or signal processing can be simplified when dispersion compensation is performed by signal processing.

Also, the insertion of the adapter lens 105 changes the distance between the optical head 900 and the subject's eye 100, thereby changing the optical path length difference between the measurement optical path and the reference optical path. Therefore, the position of the mirror 153 in the optical axis direction may be moved to a position stored in the apparatus in advance by a mirror control system (not shown) in accordance with the insertion/removal of the adapter lens 105 .

(Configuration of control section)
Next, a schematic configuration of the control unit 300 will be described with reference to FIG. The control unit 300 includes an imaging control unit 301 , a storage unit 302 , an image acquisition unit 304 and an image processing unit 305 .

The imaging control section 301 is connected to the storage section 302 , the optical head 900 and the input section 340 . The imaging control unit 301 controls each unit of the optical head 900 based on the input signal from the input unit 340 so that the inspection sequence stored in the storage unit 302 is executed.

The image acquisition unit 304 acquires an image of the subject's eye in the depth direction (Z direction) by Fourier transforming the signal obtained from the line sensor 184 and converting the obtained data into luminance or density information.

The storage unit 302 stores at least one of the tomographic image and the three-dimensional image of the anterior segment acquired by the image acquiring unit. In addition, the storage unit 302 stores at least one of the examination sequence, the generated image of the subject's eye, the analysis result of the image, the imaging conditions at the time of image acquisition, patient information, etc., and various programs used for controlling the imaging described above. You can memorize one.

An output control unit 303, which is an example of a display control unit, is connected to a display unit 310 such as a display, and outputs a tomographic image of the anterior segment stored in the storage unit 302 and a thickness map obtained by analyzing the tomographic image. display at least one of Examples of the shooting screen and the report screen displayed on the display unit 310 will be described later.

Note that the control unit 300 described above may be configured by a module executed by a CPU or MPU, or may be configured by a circuit or the like that implements a specific function such as an ASIC. The storage unit 302 can also be configured using a storage medium such as an arbitrary memory or an optical disk.

Further, the optical head 900 and the control unit 300, which are one of the measurement optical systems described above, may not be one device. For example, the technology disclosed by an ophthalmologic examination apparatus including the optical head 900 and the spectroscope 180 and a control apparatus including the control unit 300 may be implemented.

(Acquisition of tomographic image of fundus)
Acquisition of a tomographic image using an OCT apparatus, which is one of the ophthalmologic examination apparatuses according to this embodiment, will be described. By controlling the X scanner 122-1 and the Y scanner 122-2, the OCT apparatus can capture a tomographic image of a desired portion of the fundus of the eye 100 to be examined.

FIG. 3 shows how the subject's eye 100 is irradiated with the measurement light 201 and the fundus 202 is scanned in the x direction. A predetermined number of interfering light beams are detected by the line sensor 184 from the imaging range of the fundus 202 in the x direction. The image acquisition unit 304 performs signal processing such as wavenumber transform, dispersion compensation calculation, and Fourier transform (FFT) on the luminance distribution signal on the line sensor 184 obtained at a certain position in the x direction.

An A-scan image is obtained by converting the linear luminance distribution obtained by FFT into density or color information to display it on a monitor. A two-dimensional image in which a plurality of A-scan images are arranged is called a B-scan image. After capturing a plurality of A-scan images for constructing one B-scan image, a plurality of B-scan images are obtained by moving the scanning position in the y direction and scanning in the x direction again. The B-scan image is further subjected to processing such as brightness adjustment by the image acquisition unit 304 and displayed on the screen.

By displaying a plurality of B-scan images or a three-dimensional tomographic image constructed from a plurality of B-scan images on a monitor, the examiner can diagnose the subject's eye. Also, the method for constructing the tomographic image described above is the same for the anterior ocular segment of the eye 100 to be examined.

(Acquisition of tomographic image of anterior segment)
FIG. 4 is an optical path diagram of the measurement light when the adapter lens 105 is not inserted, and FIG. 5 is an optical path diagram of the measurement light when the adapter lens 105 is inserted. Reference numeral 203 denotes a conjugate point of the image plane (the fundus in FIG. 4 and the anterior segment in FIG. 5).

In the optical path of FIG. 5, the adapter lens 105 is arranged at the pupil position of the optical system. The pupil position is the optical conjugate position of the center points of the X scanner 122-1 and Y scanner 122-2. With this configuration, the exit pupil position of the optical system is placed at a finite distance, and the optical path for scanning the anterior segment is not parallel to the optical axis (non-telecentric configuration). In addition, the adapter lens 105 can be made compact, and the distance (working distance) between the lens 101-1 and the subject's eye 100 can be shortened even during imaging of the anterior segment.

When acquiring a tomographic image of the anterior segment with a wide angle of view, the fact that the anterior segment of the eye, for example, the peripheral part of the cornea, is farther from the optical head than the central part of the cornea, and thus is photographed darker, is a difference between non-telecentricity and telecentricity. can occur in any configuration. Among them, in a non-telecentric configuration, since the image plane position and the cornea are curved in opposite directions, the corneal periphery tends to be dark and photographed.

Here, the image plane position refers to a plane formed by focusing measurement light at each angle of view. The image plane position is a plane including the focus position, which is the focal point on the optical axis, and in this specification, the image plane position is adjusted by adjusting the focus position.

On the other hand, when acquiring a tomographic image of the anterior segment with this configuration, the scan range of the subject's eye 100 changes according to the working distance. When the scan range changes, the angle of view of the displayed B-scan image of the anterior segment changes, making it difficult to accurately measure the distance to the subject's eye 100 . Therefore, it is necessary to determine the working distance with high accuracy.

In order to accurately determine the working distance, the tomographic image is used to align the optical head 900 and the subject's eye 100 to determine the working distance. First, the reference optical path length is fixed. Specifically, the mirror control system (not shown) moves the position of the mirror 153 in the optical axis direction to a position stored in advance in the apparatus, and fixes the mirror 153 at that position.

Alignment is performed so that the vertex of the cornea of the subject's eye 100 is aligned with the alignment reference line 212-1 in FIG. 11, which will be described later, with the mirror 153 fixed. The alignment reference line indicates the position where the difference between the optical path length of the reference light and the optical path length of the measurement light becomes a predetermined value. As the alignment, the optical head 900 may be manually adjusted by the operator, or the corneal vertex position may be automatically determined and the alignment may be performed automatically.

Moreover, the part of the eye 100 to be examined that is aligned with the alignment reference line does not have to be the apex of the cornea, and may be the structure inside the anterior segment of the eye 100 to be examined, such as the internal structure of the cornea, the iris, or the crystalline lens. Furthermore, by performing the operation of correcting variations in the optical path length of the main body in advance, it becomes easier to determine the working distance uniquely and accurately measure the distance.

(Acquisition of a tomographic image of the anterior segment with a wide angle of view)
FIG. 6 is an enlarged view of the cornea and the adapter lens 105 of the eye 100 to be examined in FIG. The image plane position 230 represents the position where the rays of each field angle are focused, that is, the image plane position of the optical system. A permissible image plane range 231, which is an example of the focus range, is a range within a predetermined distance from the image plane position 230, and represents a range in which the OCT image looks bright, that is, a range permissible for imaging.

Here, the image plane position refers to a plane formed by focusing measurement light at each angle of view. The image plane position is a plane including the focus position, which is the focal point on the optical axis, and in this specification, the image plane position is adjusted by adjusting the focus position.

In FIG. 6, the image plane position 230 is illustrated as a straight line, but it often exhibits curved characteristics depending on the characteristics of the optical system. In this case, the allowable image plane range 231 is also curved. Further, by driving the OCT focusing lens 123 with a motor (not shown), the image plane position 230 can be moved with respect to the eye 100 to be examined.

It is also possible to design the adapter lens 105 optical system so that the image plane position 230 is curved along the cornea. However, since the direction of the curvature of the fundus of the eye 100 to be examined is generally opposite to the direction of the curvature of the cornea, an apparatus that obtains the fundus as in the present embodiment cannot It is common to make an optical design suitable for the curvature of .

Here, if the adapter lens is optically designed to have a reverse curvature, the configuration of the adapter lens 105 becomes large-scale. In this embodiment, a technique for obtaining a clear tomographic image of the anterior segment while simplifying and reducing the cost of the adapter lens 105 will be described.

Reference numeral 235 denotes an optical axis, 232 a light ray irradiated to the center of the cornea of the eye 100 to be examined, 233 an outermost light ray when the cornea of the eye 100 to be examined is acquired at a narrow angle of view, and 234 a light ray of the eye 100 to be examined. It is the outermost ray when the cornea is broadly acquired.

When acquiring a tomographic image with a narrow angle of view, the tomographic image is acquired by focusing on the corneal vertex and arranging the image plane position 230 near the corneal vertex so that the vicinity of the corneal vertex of the eye 100 to be examined becomes bright.

FIG. 7 shows the positional relationship between the image plane position 230 and the allowable image plane range 231 when a tomographic image is acquired at a wider angle of view than in FIG. Control is performed so that the swing angles of the OCTX scanner 122-1 and the OCTY scanner 122-2 are changed depending on whether a narrow angle of view is to be obtained or a wide angle of view is to be obtained. When acquiring a tomographic image with a wide angle of view, it is set in advance so that the OCTX scanner 122-1 and the OCTY scanner 122-2 are controlled at a larger swing angle than when acquiring a tomographic image with a narrow angle of view. there is 231 to 235 have the same configuration as the configuration described in FIG. 6, so description thereof is omitted.

FIG. 7 is a schematic diagram in which the image plane position 230 is moved from the image plane position 230 in FIG. 6 in a direction away from the ophthalmologic examination apparatus. Image plane position 230 includes the focus position and is moved by moving OCT focusing lens 123 .

The position of the OCT focusing lens 123 is stored in the apparatus so that it can be switched between two modes, for example, when acquiring a tomographic image in a narrow range and when acquiring a tomographic image in a wide range. When the above mode is selected, the position of the OCT focusing lens 123 is driven to the respective stored position, enabling acquisition of a tomographic image.

As the position of the OCT focusing lens 123, the position of the focusing lens in the optical head may be stored, or the relative distance from the position of the corneal vertex detected by a sensor or the like may be stored. .

Also, in the present embodiment, photographing at 6 mm as the first mode and photographing at 9 mm as the second mode will be described, but the angle of view is not limited to these. Other angles of view may be set in advance, and three or more angles of view may be set. For example, when the angle of view of 7 mm is set as the third mode, the position of the focusing lens 123 when shooting at 6 mm and the position of the focusing lens 123 when shooting at 9 mm is intermediate. The focusing lens 123 should be moved.

The positions of the focusing lens 112 and the focusing lens 123 when photographing the fundus and when photographing the anterior segment may be corrected in advance for each device. The correction is performed using a simulated eye to be examined as a reference corresponding to each diopter as a substitute for the eye to be examined 100, and the in-focus lens position between them is obtained by interpolation. For the focusing lens position when photographing the anterior segment, a reflecting object or the like (not shown) serving as a reference is arranged at a predetermined position, and the focusing lens position is obtained based on the position of this reflecting object 222 . For example, it can be obtained by determining the position where the brightness of the reflecting object in the tomographic image is the highest.

In order to store the positions of the OCT focusing lens 123 corresponding to a plurality of modes, a plurality of reflecting object positions may be arranged, or a position shifted by a predetermined amount from the position of one reflecting object may be stored. .

By moving the image plane position 230 in a direction deeper than the corneal vertex (negative direction in the Z direction), the corneal periphery, which was outside the allowable image plane range 231 in FIG. 6, is now within the allowable image plane range 231 in FIG. can enter. In addition, it is possible to irradiate the subject's eye inside the permissible image plane range 231 even with the light rays of the outermost angle of view. This makes it possible to obtain a bright OCT image from the ray at the center of the cornea to the ray at the outermost angle of view.

In this embodiment, when acquiring a tomographic image in a wide range, the position of the OCT focusing lens 123 is driven to move the image plane position 230. However, the present invention is not limited to this.

In the above description, the position of the focusing lens 123 is adjusted to move the image plane position 230 and the allowable image plane range 231 in the eye 100 to be inspected, but the present invention is not limited to this. As the configuration of the focusing lens 123, a lens (such as a liquid lens) that changes the focal length by electrical control may be used.

This lens is characterized by being able to change the focal length at high speed by electrical control. Since the focal length of this lens can be controlled at high speed, the focal position may be changed for each B-scan image, and the image plane position 230 and allowable image plane range 231 may be moved according to the B-scan position. The image plane position 230 can always be matched on the cornea of the eye 100 to be inspected in units of B scans, and a brighter image with good contrast can be obtained.

In addition, by reducing the NA (numerical aperture) of light rays, the depth of focus can be increased, and the allowable image plane range 231 can be widened. A tomographic image with a wide angle of view may be acquired by changing only the NA (numerical aperture) without changing the image plane position, or moving the image plane position away from the ophthalmologic examination apparatus and NA (numerical aperture) may be configured to be smaller.

For example, as an example of changing means for changing the depth of focus, an insertable/removable optical member may be provided in the optical path between the fiber end 126 and the eye 100 to be examined. Any optical member such as a lens or a diaphragm may be used as the changing means. It is also possible to switch the NA (numerical aperture) by replacing the lens between when acquiring a tomographic image with a normal NA (numerical aperture) and when acquiring a tomographic image with a small NA (numerical aperture). is.

FIG. 8A shows the relationship between the image plane position 230 and the allowable image plane range 231 when NA (numerical aperture) is reduced. By decreasing the NA (numerical aperture), the depth of focus is increased, and the allowable image plane range 231 can be widened. Therefore, when obtaining a tomographic image over a wide range, it is possible to obtain a clear OCT image from the light beam at the center of the cornea to the light beam at the outermost angle of view.

FIG. 8B shows the relationship between the spread of rays and the permissible image plane range 231 when NA (numerical aperture) is large and small. When the NA (numerical aperture) is large, the spot diameter of the light ray at the image plane position 230 is large, but since the angle of the light ray is small, the light ray spreads as it moves away from the image plane position 230, and the allowable image plane range 231 becomes narrower.

On the other hand, when the NA (numerical aperture) is small, the spot diameter of the light beam at the image plane position 230 is large, but the angle of the light beam is small, so the light beam does not spread immediately even if it moves away from the image plane position 230. The permissible image plane range 231 is widened. That is, by decreasing the NA (numerical aperture), the permissible image plane range 231 is widened. It is possible to acquire a tomographic image within the allowable image plane range 231 up to .

Furthermore, although an example of performing control so as to change the swing angles of the OCTX scanner 122-1 and the OCTY scanner 122-2 depending on the angle of view has been described, the structure may be such that the swing angles are not changed. For example, in FIGS. 6 and 7, the distance between the adapter lens 105 and the subject's eye 100 may be changed. By changing the distance, it is possible to widen or narrow the angle of view in proportion to the intersection of the optical axis 235 and the light beams 232 , 233 , 234 . When the angle of view is to be changed, the focusing lens 123 and the reference mirror are driven so that the image plane position is located in the depth direction from the corneal vertex.

Moreover, although the part of the eye 100 to be examined for obtaining a tomographic image is the cornea, it is not limited to this. The configuration described above is also effective when acquiring a tomographic image of the anterior segment of the eye such as the iris or the lens.

(Display of tomographic image)
Display of the acquired tomographic image of the anterior segment will be described. As an optical characteristic, within the permissible image plane range 231, the brightness of the obtained tomographic image is the brightest near the image plane position 230 and becomes darker as the distance from the image plane position 230 increases. The concentration (focus) of rays is the smallest at the image plane position 230, and increases as the distance from the image plane position 230 increases. This is due to the fact that it gets dark.

When a tomographic image is acquired in a relatively narrow range as shown in FIG. 6, the tomographic image is acquired at a position close to the image plane position 230, so the tomographic image is bright as a whole. On the other hand, when a tomographic image is acquired over a relatively wide range as shown in FIG. 7, the tomographic image tends to be dark because the tomographic image is also acquired at a position far from the image plane position 230 .

Due to these optical characteristics, even when tomographic images of the same region are acquired, the brightness of the tomographic image may change between a narrow angle of view and a wide angle of view. On the other hand, when tomographic images of the same site are obtained with different brightness, it may interfere with diagnosis. , should be displayed with the same brightness as possible.

Here, in order to acquire tomographic images with the same brightness when acquiring a tomographic image with a narrow angle of view and when acquiring a tomographic image with a wide angle of view, we have individual parameters for adjusting the brightness. It may be configured as follows. Specifically, the image acquisition unit 304, which is an example of image correction means for adjusting at least one of brightness and contrast, processes the output signal from the spectroscope 180 and acquires a tomographic image of the fundus of the eye 100 to be examined. do. At this time, in the processing of the output signal, the image acquisition unit 304 automatically has parameters for adjusting brightness and contrast, and automatically performs different brightness and contrast adjustments.

For brightness and contrast, when acquiring tomographic images with a narrow angle of view and when acquiring tomographic images with a wide angle of view, multiple images, multiple aircraft, and multiple eyes are acquired and compared to obtain the same brightness. You may decide beforehand the parameter which becomes. More specifically, when obtaining a tomographic image with a narrow angle of view of 6 mm and a wide angle of view of 9 mm, it is desirable to set the brightness to +5 and the contrast to +25.

In addition, an index obtained by evaluating image quality may be displayed for a tomographic image that has already been acquired or a tomographic image that is being acquired. If it is an acquired image, the examiner may determine the validity of the acquired image by comparing it with the image quality index of similar imaging in the past while using the image quality index as a guide. If it is an image that is being acquired, it may be configured such that it can be determined whether or not the adjustment state of the apparatus such as alignment is correct. This quality indicator is generally obtained based on the signal strength to noise ratio of the image.

Here, due to optical characteristics, signal intensity may be high when acquiring a tomographic image with a narrow angle of view, and may be low when acquiring a tomographic image with a wide angle of view. For this reason, if the ratio of signal strength to noise is simply used as an index of image quality, the index of image quality will differ depending on the angle of view, making it difficult to determine whether adjustments for image acquisition are appropriate. difficult.

In order to appropriately display the index of image quality even for images with different angles of view, parameters for obtaining the index of image quality may be individually set for each angle of view. Specifically, the image processing unit 305, which is an example of image quality evaluation means for evaluating image quality, processes the output signal from the spectroscope 180 and acquires a tomographic image of the fundus of the eye 100 to be examined.

At this time, in the processing of the output signal, each image quality index is calculated using different parameters for each angle of view in order to obtain the image quality index. As a process of obtaining an index of image quality, a process of multiplying the ratio of signal intensity and noise by a coefficient, which is a parameter that differs for each angle of view, may be performed. For example, the coefficient for imaging the anterior segment with a wide angle of view is set to a larger value than the coefficient for imaging the anterior segment with a narrow angle of view.

Acquire images with the same brightness by acquiring and comparing multiple images, multiple aircraft, and multiple eyes when acquiring tomographic images with a narrow angle of view and acquiring tomographic images with a wide angle of view. You may determine the parameter for doing beforehand. More specifically, when acquiring a tomographic image with a narrow angle of view of 6 mm and a wide angle of view of 9 mm, the parameter is changed from 1.4 to 1.4 as compared to the case of acquiring a tomographic image with a 6 mm angle of view. It is desirable to increase it by about 5 times.

Also, the criteria for evaluating the image quality may be changed for each angle of view. For example, the image quality index for a wide angle of view and a narrow angle of view may be obtained by the same method, and the evaluation criteria for the obtained image quality may be changed. Specifically, when displaying the index of image quality, green is displayed when the index is above a certain level, and yellow or red is displayed when the index is below a certain level. may also be configured so that the wide angle is lower.

(Display screen)
Next, the configuration of the screen when the output control unit 303, which is an example of the display control unit, causes the display unit 310 to display the test results will be described.

FIG. 9 shows an example of screen transition in this embodiment. In FIG. 9, a login screen 361 is the first screen displayed after the apparatus is started, and the operator can perform various operations by logging in from the login screen 361 . Note that the initial setting screen 365 is a screen on which initial settings for various operations can be performed by logging in from the login screen, and settings different from those on the setting screen 366 are performed. On the initial setting screen 365, it is possible to set items that are changed infrequently by setting once. For example, login user management, data storage destination management, license management, and the like.

On the setting screen 366, it is possible to set items to be changed for each operator or according to the timing of shooting, such as settings during shooting and display settings. For example, it is the display setting of the internal fixation light and the setting of the shortcut key. A patient screen 362 is a screen that displays a list of patient data. A report screen 363 is a screen that displays the examination results (imaging results) for each patient. A photographing screen 364 is a screen for photographing by operating the optical head 900 or the like.

FIG. 10 shows an example of the patient screen 362 in this embodiment. In the patient screen 362, 401 represents a patient tab, 402 an imaging tab, 403 a report tab, and 404 a setting tab. It also has a patient information input section 410 , a patient list display section 420 and an examination list 430 .

In patient screen 362, the operator selects patient data from patient list 420 and selects exam data for the selected patient data. FIG. 10 shows an example of selecting patient ID 00005 from the patient list 420 and selecting the top test data (for example, the latest test result) from the test list 430 . To display the report screen 363 of the examination data selected from the patient screen 362, for example, by double-tapping the examination data, the report screen 363 shown in FIG. 12A, which will be described later, is displayed.

FIG. 11 shows an example of the shooting screen 364 in this embodiment. This is an image displayed on the monitor during imaging of the anterior segment when the adapter lens 105 is inserted. The monitor indicates a monitor mounted on the main body of the apparatus or a PC monitor.

The cursor 1002 is moved on the patient screen 364 by operating means such as a mouse, the left and right eyes are selected by the left/right eye switching button 1001 , and the scan mode is selected by the Scan Mode button 1501 . As the scan mode, Macula3D, Glaucoma3D, Disc3D, and OCTA, which are modes for acquiring a tomographic image of the fundus, can be selected. In addition, as a scan mode, there is a mode in which a tomographic image of the anterior segment is acquired with a narrow angle of view, which is a first mode, and a mode in which a tomographic image of the anterior segment is acquired with a wide angle of view, which is a second mode. You can choose either In addition, there is a fundus photography mode, a mode for obtaining fundus fluorescence photography, and the like.

In this embodiment, as a mode for acquiring a tomographic image of the anterior segment, a 6 mm angle of view is used as a mode for acquiring a tomographic image with a narrow angle of view, and a 9 mm angle of view is used as a mode for acquiring a tomographic image with a wide angle of view. An example of selection is shown. When each mode is selected by the user, the focus position adjustment by the lens 112 described above is automatically set. Brightness and contrast settings and image quality index settings are also automatically set. Regardless of which mode is selected by these main body settings and display settings, it is possible to obtain and display an appropriate tomographic image. In addition to the mode selected by the user, the default imaging mode may be set in advance.

When the scan mode is switched, the optimum scan pattern and fixation position are set for each scan mode. Scanning patterns for tomographic images include 3D scanning, radial scanning, cross scanning, circle scanning, raster scanning, and the like. In this embodiment, a case where radial scanning is selected as the scanning pattern will be described.

When photographing the anterior segment when the adapter lens 105 is inserted, a two-dimensional image of the anterior segment is displayed on the screen 1101, a two-dimensional image of the anterior segment is displayed on the screen 1201, and a tomographic image of the anterior segment is displayed on the screen 1301. A B-scan image is displayed. The two-dimensional images of the anterior segment at this time, both the screen 1101 and the screen 1202, are images processed by the image acquisition unit 304 from the output of the single detector 116 and displayed.

In either case, the displayed B-scan image is an image constructed from the output of the line sensor 184 through the above-described processing. An alignment reference line 212-1 is displayed in the screen 1301 in advance. By adjusting the corneal vertex position of the subject's eye 100 to the alignment reference line 212-1 in the screen 1301, the working distance can be adjusted to a predetermined value.

By pressing the Start button 1004, alignment adjustment is automatically performed and preparations for photographing are performed. When finely adjusting the alignment, the slider 1103 is used to move the Z-direction position and the XY position of the optical head with respect to the eye to be inspected while viewing the anterior eye observation image 1101 .

An index of image quality is displayed as a bar indicated at 1005 . When the image quality is high, the bar display has more black areas to the right, and the opposite is true when the image quality is low. As described above, the index of image quality is calculated in order to obtain the same index of image quality when obtaining a tomographic image with a narrow angle of view and when obtaining a tomographic image with a wide angle of view. Each has its own coefficient for each, and the image quality is evaluated according to different criteria.

Here, an example of bar display is shown, but the present invention is not limited to this, and examples of displaying values, displaying with scales, displaying colors, or a combination thereof may be used.

Focus adjustment is performed using a slider 1203 while viewing an image processed and displayed by the image acquisition unit 304 from the output of the single detector 116 . The focus adjustment is an adjustment of moving the lens 112 in the illustrated direction in order to adjust the focus on the anterior segment. Here, when the focus is adjusted, only the lens 112 is driven, and the lens 123 is photographed by fixing the image plane position 230 as described above, so drive control is not performed.

Since the coherence gate position is fixed at a preset position, the slider 1302 is only displayed and cannot be adjusted. Adjust the size and position of 1203 to select the scan area. When the Capture button 1003 is pressed, the image is captured. Radial scanning is performed by scanning the XY scanners 153-1 and 153-2.

The alignment reference line 212-1 in the screen 1301 and the coherence gate position are the same regardless of which of the 6 mm angle of view and the 9 mm angle of view mode is selected as the mode for acquiring a tomographic image of the anterior segment. Acquire a tomographic image. This is because, as described above, a change in the distance in the Z direction between the eye 100 to be examined and the optical head 900 causes a difference in the obtained angle of view. By keeping the distance in the Z direction constant, a desired acquisition range (angle of view of 6 mm and 9 mm in this example) can be acquired.

Further, the configuration may be such that the allowable image plane range 231 is displayed on the photographing screen. By displaying the allowable image plane range 231 on the photographing screen, the user can perform fine adjustment while confirming the focus position suitable for photographing, so that photographing can be performed in accordance with the user's intention.

FIG. 12 shows an example of the report screen 363 in this embodiment. The report screen 363 is configured so that it can be switched by operating tabs, as shown in FIGS. 12A to 12E. The report screen 363 includes a patient information display section 510, an examination result display section 520, and an examination list display section 530 as common displays. A black frame 531 in the inspection list display portion 530 represents inspection data displayed in the inspection result display portion 520 .

FIG. 12A is a screen when the Single tab is selected. The Single screen displays results for a single examination. A display unit 520-1 included in the examination result display unit 520 displays a corneal thickness map as an example of a thickness map of the acquired tomographic image. Along with a map that is color-coded according to corneal thickness, the corneal thickness value for each region dividing the map is displayed.

A thickness map of the corneal epithelium is similarly displayed on the display unit 520-2. Color coding and display of corneal epithelial thickness values for each region are the same as 520-1.

These thickness map regions are delimited, for example, concentrically from the center of the cornea. Also, for example, the regions are divided in the rotational direction according to the number of radial scans. As an example, a thickness map divided into eight in the direction of rotation will be described, but the number of divisions may be different, and the number of divisions may be changed.

The size of the concentric circles is set in advance to, for example, diameters of 2, 5, 7, and 9 mm, but may be changed by initial setting or the like. In addition, in a configuration in which a tomographic image can be acquired with a narrow angle of view of 6 mm and a wide angle of view of 9 mm, the sizes of concentric circles may be set in advance to diameters of 2, 6, and 9 mm.

Also, an example of displaying one of the acquired tomographic images in 520-3 is shown, but a plurality of tomographic images may be displayed, or only the tomographic image corresponding to the selected region may be displayed. Further, the tomographic image to be displayed may be switched by an operation such as a slide bar operation or a drag operation.

In 520-4, an index of image quality of the acquired tomographic image is displayed as a bar. 520-5 shows an example of a table showing the statistical distribution of the acquired corneal thickness and the difference for each area.

FIG. 12B is a screen when the Both Eyes tab is selected. The left and right eye results are displayed simultaneously in order to compare the results of the tests acquired with both eyes. Since 520-1 to 520-5 are the same displays as in FIG. 12A, their description is omitted. The imaging displayed with a black frame 531 in the examination list display portion 530 indicates the selected imaging. The test result display section 520 displays left and right eyes at the same time, and is a display for confirming the comparison of each test.

FIG. 12C is a screen when the Comparison tab is selected. To compare arbitrary test results, two test results are displayed side by side. Selection of an inspection target to be compared can be made in the inspection list display section 530 . Since 520-1 to 520-5 are the same display as the display in FIG. 12A, description thereof is omitted. At 520-6, it is possible to display a map screen displaying differences in thickness measurement values between arbitrarily selected inspections, and visually display thickness comparison results between arbitrarily selected inspections. be.

FIG. 12D shows the screen when the Progression tab is selected. In order to confirm changes in time series, the images and measured values are displayed from left to right in order of acquisition date and time, and the display is configured so that these can be compared.

Since 520-1 to 520-5 are the same display as the display in FIG. 12A, description thereof is omitted. In this embodiment, the corneal thickness, the thickness of the corneal epithelium, and the tomographic image are displayed side by side for five measurement days. In 520-7, the values of the corneal thickness are displayed on a graph for each of these five measurement days, and the degree of change over the course of one year is simultaneously displayed using fitting such as the least squares method. . In 520-5, the numerical value of the degree of change is displayed in %.

FIG. 12E is a display when the range acquired with a 9 mm angle of view in FIG. 12A is acquired with a 6 mm angle of view. When the black frame 531 in the examination list display portion 530 is selected to be 6 mm, it is set in advance so that the map display is switched accordingly.

The corneal thickness map of 520-1 and the corneal epithelial thickness map of 520-2 are displayed with diameters of 2, 4, and 6 mm, for example. may be displayed. 520-3 is designed to display 6 mm on the screen, but the horizontal direction may be shortened to match the scale with 9 mm. 520-5 shows an example of a table showing the statistical distribution of the corneal thickness obtained at the angle of view of 6 mm and the difference for each region.

When selecting each of the Both Eyes, Comparison, and Progression tabs, the configuration is such that comparison can be made according to the angle of view of 6 mm. In both eyes, comparison, and progression, comparison may be made by mixing both the 6 mm angle of view and the 9 mm angle of view. Here, Both Eyes refers to a report screen on which tomographic images of left and right eyes are displayed side by side. Also, Progression refers to a report screen that displays side by side tomographic images or thickness maps acquired on a plurality of different inspection days.

FIG. 12F is a screen when the Comparison tab is selected. The black frame 531 selects an inspection with an angle of view of 6 mm and an inspection with an angle of 9 mm, and the display unit 520 displays a thickness map, a tomographic image, and a corneal thickness when acquired with, for example, a 6 mm angle of view on the left side and a 9 mm angle of view on the right side. An example of a table showing the statistical distribution of and differences for each region is shown. In order to be able to compare the two within a field angle of 6 mm from the center, the size of the divided regions in the analysis of the thickness map was matched, and the tomographic image was enlarged, reduced, or trimmed. may A configuration is also possible in which a plurality of inspection results acquired at different angles of view are displayed side by side without being processed.

Similarly, the Both Eyes may be configured to display side by side the results acquired with a field angle of 6 mm for one eye and a field angle of 9 mm for the other eye. Also, in Progression, even when a plurality of inspection results including inspection results with different angles of view are selected, the change in the inspection results over time may be confirmed.

As the report screen, the screen for displaying the test result of the anterior segment has been described, but the configuration may be such that the test result of the segment other than the anterior segment is also displayed. For example, the test results of the fundus and the anterior segment of the same patient may be displayed side by side on one screen.

<Example 2>
In Embodiment 1, the adapter lens 105 is used to acquire a tomographic image of the anterior segment of the eye 100 to be examined, but it is also possible to acquire a tomographic image of the anterior segment of the eye without using the adapter lens 105. be.

A configuration example in which the adapter lens 105 is not used will be described with reference to FIGS. 13(a) and 13(b). FIG. 13A is the same configuration as that of FIG. 4, and is a configuration for obtaining a tomographic image of the fundus. FIG. 5B shows a configuration for obtaining a tomographic image of the anterior segment without using the adapter lens 105 .

203 is the conjugate point of the image plane (the fundus in FIG. 4 and the anterior eye in FIG. 5). Become. Specifically, the conjugate point 203 can be moved by driving the lens 123 . On the other hand, if the conjugate point 203 is configured to be largely movable, the size of the apparatus may be increased and high-precision adjustment may be required due to restrictions on the focal length and driving range of the lens 123 .

In addition, the conjugate point 203 can be moved by increasing the distance in the Z direction between the subject's eye 100 and the optical head 900 compared to the case of acquiring a tomographic image of the fundus with the configuration of FIG. 13(a). . In this case, the necessary apparatus becomes large, so in this embodiment, an example in which both the position of the lens 123 and the distance in the Z direction between the eye 100 to be inspected and the optical head 900 are changed will be described.

With this configuration, it is possible to acquire a tomographic image of the anterior segment even when the adapter lens 105 is not used.

Dispersion compensation will be explained. For example, glass having the same dispersion (not shown) may be inserted into the optical path L1 in the optical head 900. Also, the dispersion compensating glass 152 is adjusted to the dispersion of the eye 100 to be examined, and a tomographic image of the anterior segment is obtained. When acquiring, the configuration is possible even if the dispersion compensating glass 152 is removed from the optical path. In addition, dispersion correction may be performed by performing rearrangement calculation, which is numerical processing, on the acquired interference signals.

Further, in the technology disclosed in this specification, the swing angle of the measurement light is set in advance according to the angle of view. That is, the swing angle of the measurement light is set for each of the first mode and the second mode, and the swing angle of the second mode is larger than the swing angle of the first mode. When changing the angle of view for acquiring a tomographic image, the swing angle of the OCTX scanner 122-1 and the OCTX scanner 122-2 is changed to acquire the tomographic image, which is the same as in the first embodiment, so the description is omitted. do.

The tomographic image is obtained by changing the image plane position 230 and shifting the allowable image plane range 231, different calculations are performed for brightness and image indices, the alignment method, each display method, etc. are the same as those in the first embodiment. Therefore, the description is omitted.

<Other Examples>
Note that the technology disclosed in this specification may be realized by an ophthalmologic examination system in which an ophthalmologic examination apparatus and an image processing apparatus are configured to be connectable. Also, the technology disclosed herein may be implemented by a control device capable of controlling an ophthalmologic examination apparatus. Any one of a personal computer, a tablet terminal, a smartphone, or the like may be used as the image processing device or the control device.

In addition, the technology disclosed in this specification supplies software (programs) that realize one or more functions of the various embodiments described above to a system or device via a network or a storage medium, and the system or device can also be implemented by a process in which the computer reads and executes the program. A computer has one or more processors or circuits and may include separate computers or a network of separate processors or circuits for reading and executing computer-executable instructions.

As such, the processor or circuitry may include a central processing unit (CPU), a microprocessing unit (MPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), or a field programmable gateway (FPGA). Also, the processor or circuitry may include a digital signal processor (DSP), data flow processor (DFP), or neural processing unit (NPU).

Claims (29)

An ophthalmologic examination apparatus for acquiring a tomographic image of the anterior segment of the eye using interference light obtained by combining reference light and return light from the anterior segment of an eye to be examined irradiated with measurement light,
scanning means for scanning the measurement light in the anterior segment;
driving means for driving focusing means for adjusting the focus position of the measurement light;
A plurality of modes including a first mode in which a first swing angle is set as a swing angle for scanning the measurement light and a second mode in which a second swing angle larger than the first swing angle is set When the second mode is selected from among the modes, the driving means is controlled so that the focus position of the measurement light becomes farther from the ophthalmologic examination apparatus than the focus position set in the first mode. a control means;
An ophthalmic examination device comprising: The driving means drives a focusing lens as the focusing means,
2. The ophthalmologic examination apparatus according to claim 1, further comprising storage means for storing in advance the position of said focusing lens according to at least one of said first mode and said second mode. An ophthalmologic examination apparatus for acquiring a tomographic image of the anterior segment of the eye using interference light obtained by combining reference light and return light from the anterior segment of an eye to be examined irradiated with measurement light,
scanning means for scanning the measurement light in the anterior segment;
changing means for changing the depth of focus of the measurement light;
A plurality of modes including a first mode in which a first swing angle is set as a swing angle for scanning the measurement light and a second mode in which a second swing angle larger than the first swing angle is set Control means for controlling the changing means such that when the second mode is selected from among the modes, the depth of focus of the measurement light becomes deeper than the depth of focus set in the first mode;
An ophthalmic examination device comprising: 4. The ophthalmologic examination apparatus according to claim 3, wherein said changing means changes said depth of focus by inserting or removing at least one lens in the optical path of said measurement light. 5. The controller according to any one of claims 1 to 4, wherein the control means selects a mode according to a user's instruction to select one of a plurality of modes including the first mode and the second mode. 10. An ophthalmologic examination apparatus according to claim 1. further comprising image quality evaluation means for evaluating the image quality of the obtained tomographic image,
6. The image quality evaluation means according to any one of claims 1 to 5, wherein the image quality evaluation means evaluates the image quality of the tomographic image captured in the first mode and the image quality of the tomographic image captured in the second mode based on different criteria. 1. The ophthalmologic examination apparatus according to claim 1. further comprising image quality evaluation means for evaluating the image quality by obtaining an image quality index of the acquired tomographic image;
The image quality evaluation means, when the signal strength of the interference signal acquired in the first mode and the second mode is equal, than the index of the image quality of the tomographic image captured in the first mode, 7. The ophthalmologic examination apparatus according to any one of claims 1 to 6, wherein said tomographic image captured in said second mode acquires said index so as to increase said index of image quality. In the optical system of the ophthalmologic examination apparatus, the exit pupil position of the measurement light is placed at a finite distance, and the optical path along which the measurement light scans the anterior segment of the eye to be examined is non-telecentric with respect to the optical axis. 8. The ophthalmologic examination apparatus according to any one of claims 1 to 7, which is an optical system. 9. The ophthalmologic examination according to any one of claims 1 to 8, wherein a target part for acquiring a tomographic image is switched between the fundus and the anterior segment of the eye by inserting and removing at least one lens in the optical system of the ophthalmologic examination apparatus. inspection equipment. 10. The ophthalmologic examination apparatus according to claim 9, wherein a convex lens as said at least one lens is inserted into and removed from the optical system of said ophthalmologic examination apparatus, thereby switching a target region for obtaining a tomographic image between the fundus and the anterior segment of the eye. 3. The drive means switches the target part for acquiring the tomographic image between the fundus and the anterior eye by changing the position of the focusing means and the distance between the eye to be examined and the ophthalmologic examination apparatus. 11. The ophthalmologic examination apparatus according to any one of 1 to 10. further comprising display control means for causing a display unit to display a setting screen for accepting an instruction to select one of a plurality of modes including the first mode and the second mode,
The ophthalmologic examination apparatus according to any one of claims 1 to 11, wherein the display control means displays the acquired tomographic image on a display unit. 13. The ophthalmic examination apparatus according to claim 12, wherein said display control means causes said display unit to display a thickness map obtained by analyzing said acquired tomographic image. The display control means uses, as a thickness map obtained by analyzing the acquired tomographic image, at least one of the corneal thickness and the thickness of the corneal epithelium concentrically separated from the central portion of the cornea of the eye to be examined. 14. The ophthalmologic examination apparatus according to claim 13, wherein a thickness map is displayed on said display unit. 15. The ophthalmologic examination apparatus according to claim 13, wherein said display control means changes a diameter of concentrically dividing said thickness map in accordance with a user's instruction. 16. The ophthalmologic examination apparatus according to any one of claims 13 to 15, wherein said display control means changes the range of said anterior segment displayed as said thickness map according to a user's instruction. When causing the display unit to display a thickness map obtained by analyzing a plurality of tomographic images including tomographic images captured in different modes as the thickness map, the display control means displays the thickness map as the plurality of thickness maps. 17. The ophthalmologic examination apparatus according to any one of claims 13 to 16, wherein the range of analysis of the plurality of tomographic images is changed or the thickness map is processed so that the range of the anterior segment of the eye becomes equal. 18. The ophthalmologic examination apparatus according to any one of claims 12 to 17, wherein said display control means causes said display unit to display said tomographic image and information indicating image quality of said tomographic image. 19. The ophthalmologic examination apparatus according to any one of claims 12 to 18, wherein the display control means causes the display unit to display tomographic images of left and right eyes as the tomographic images. The ophthalmic examination apparatus according to any one of claims 12 to 19, wherein the display control means causes the display unit to display tomographic images obtained on a plurality of different examination days as the tomographic images. An ophthalmologic examination apparatus for acquiring a tomographic image of the anterior segment of the eye using interference light obtained by combining reference light and return light from the anterior segment of an eye to be examined irradiated with measurement light,
scanning means for scanning the measurement light in the anterior segment;
A plurality of modes including a first mode in which a first swing angle is set as a swing angle for scanning the measurement light and a second mode in which a second swing angle larger than the first swing angle is set Adjusting means for adjusting the optical system such that when the second mode is selected from among the modes, the range in which the measurement light is focused becomes a focus range different from the focus range set in the first mode. and,
An ophthalmic examination device comprising: An ophthalmologic examination system configured such that the ophthalmologic examination apparatus according to any one of claims 1 to 21 and an image processing apparatus are connectable. The anterior eye to which the measurement light is irradiated, comprising scanning means for scanning the anterior segment of the eye to be inspected with the measurement light, and driving means for driving the focusing means for adjusting the focus position of the measurement light. A control device for an ophthalmologic examination apparatus that acquires a tomographic image of the anterior eye segment using interference light obtained by combining return light from the eye and reference light,
A plurality of modes including a first mode in which a first swing angle is set as a swing angle for scanning the measurement light and a second mode in which a second swing angle larger than the first swing angle is set When the second mode is selected from among the modes, the driving means is controlled so that the focus position of the measurement light becomes farther from the ophthalmologic examination apparatus than the focus position set in the first mode. A control device comprising control means. scanning means for scanning the anterior segment of the eye to be inspected with the measuring light; and changing means for changing the depth of focus of the measuring light, wherein return light and reference light from the anterior segment irradiated with the measuring light are provided. An ophthalmologic examination apparatus for obtaining a tomographic image of the anterior segment of the eye using the interference light obtained by combining the
A plurality of modes including a first mode in which a first swing angle is set as a swing angle for scanning the measurement light and a second mode in which a second swing angle larger than the first swing angle is set Control comprising control means for controlling the change means such that, when the second mode is selected from modes, the depth of focus of the measurement light becomes deeper than the depth of focus set in the first mode. Device. scanning means for scanning the anterior segment of the eye to be inspected with the measurement light; A control device for an ophthalmologic examination apparatus that acquires a tomographic image of an eye,
A plurality of modes including a first mode in which a first swing angle is set as a swing angle for scanning the measurement light and a second mode in which a second swing angle larger than the first swing angle is set Adjustment for adjusting the optical system such that, when the second mode is selected from among the modes, the focus range in which the measurement light is focused is different from the focus range set in the first mode. A control device comprising means. The anterior eye to which the measurement light is irradiated, comprising scanning means for scanning the anterior segment of the eye to be inspected with the measurement light, and driving means for driving the focusing means for adjusting the focus position of the measurement light. A control method for an ophthalmologic examination apparatus for acquiring a tomographic image of the anterior eye segment using interference light obtained by combining return light from the eye and reference light,
A plurality of modes including a first mode in which a first swing angle is set as a swing angle for scanning the measurement light and a second mode in which a second swing angle larger than the first swing angle is set When the second mode is selected from among the modes, the driving means is controlled so that the focus position of the measurement light becomes farther from the ophthalmologic examination apparatus than the focus position set in the first mode. A control method for an ophthalmic examination apparatus including steps. scanning means for scanning the anterior segment of the eye to be inspected with the measuring light; and changing means for changing the depth of focus of the measuring light, wherein return light and reference light from the anterior segment irradiated with the measuring light are provided. A control method for an ophthalmologic examination apparatus for obtaining a tomographic image of the anterior segment of the eye using the interference light obtained by combining the
A plurality of modes including a first mode in which a first swing angle is set as a swing angle for scanning the measurement light and a second mode in which a second swing angle larger than the first swing angle is set An ophthalmologic examination including the step of controlling the changing means such that, when the second mode is selected from among modes, the depth of focus of the measurement light becomes deeper than the depth of focus set in the first mode. How to control the device. scanning means for scanning the anterior segment of the eye to be inspected with the measurement light; A control method for an ophthalmologic examination apparatus that acquires a tomographic image of an eye, comprising:
A plurality of modes including a first mode in which a first swing angle is set as a swing angle for scanning the measurement light and a second mode in which a second swing angle larger than the first swing angle is set A step of adjusting an optical system such that, when the second mode is selected from the modes, the focus range in which the measurement light is focused is different from the focus range set in the first mode. A control method for an ophthalmic examination apparatus comprising: A program that causes a computer to execute the control method according to any one of claims 26 to 28.

Images