JP6214962B2 - Anterior segment cross-sectional image analyzer - Google Patents

Description

The present invention relates to an anterior ocular segment image analysis apparatus and an anterior ocular segment image analysis method that can analyze an image obtained by photographing a cross section near the corner of an anterior segment, and in particular, can acquire information related to the position or shape of an iris. .

In recent years, an optical coherence tomography apparatus for photographing a tomographic image of a subject's eye (eyeball) by optical coherence tomography (OCT) has been provided as an inspection apparatus used for ophthalmic examination. Yes.

The optical coherence tomography apparatus uses a time domain method called a time domain method, which uses a time domain OCT that acquires a tomographic image while moving a mirror and mechanically changes the optical path length of reference light, and a spectroscope called a Fourier domain method. There is a spectral domain OCT that detects spectral information and acquires a tomographic image, or an optical frequency sweep OCT that detects a spectral interference signal using a wavelength scanning light source and acquires a tomographic image.

In general, in OCT, a two-dimensional tomographic image is acquired by performing one-dimensional scanning of measurement light on a subject's eye (B-scan), and further, two-dimensional tomographic images are repeatedly acquired while shifting the position with respect to the subject's eye. By doing so, a three-dimensional image is obtained (C-scan).

As a scanning method, there is a method called a raster scan as shown in FIG. In this raster scan, a one-dimensional scan (B-scan) along a scanning line extending in the horizontal direction is repeated while shifting in the vertical direction (C-scan), and a three-dimensional image of the eyeball is photographed. As a result, as shown in FIG. 4B, a tomographic image along each scanning line can be obtained.

Furthermore, as another method, there is a method called radial scan as shown in FIG. This radial scan repeats a one-dimensional scan (B-scan) along a scan line extending in the radial direction while shifting it in the circumferential direction (C-scan). Thereby, as shown in FIG. 5B, a tomographic image along each scanning line can be obtained.

In the ophthalmology field, a tomographic image of the anterior segment of the eye to be examined is taken by a method according to the above, and glaucoma is examined using the taken tomographic image. FIG. 13 shows the positional relationship among the cornea 80, the sclera 81, the iris 82, the ciliary body 83, and the crystalline lens 84, which are representative tissues existing in the anterior eye segment. In the diagnosis of glaucoma, the evaluation is performed by paying attention to the positional relationship of the tissue existing in the region A surrounded by the rectangle in the figure, and used for the examination of the treatment policy.

FIG. 14 is a diagram in which the region A in FIG. 13 is extracted, and a region indicated by B between the cornea 80 and the iris 82 is a region called a corner angle. In the eyeball, metabolism called the aqueous humor circulation indicated by the dotted line f is performed, and the aqueous humor produced from the ciliary body 83 reaches the corner B via the rear surface of the iris 82, and the scleral cape (in the figure) SS is discharged from an area called trabecular meshwork (TM in the figure) sandwiched between characteristic areas called SS and Schwalbe line (SL in the figure) (both are dotted in the cross-sectional image). Therefore, the gap at the corner B is narrow, and furthermore, the iris 82 may be in contact with the trabecular meshwork (TM) or the rear surface of the cornea 80, and the amount of water discharged from the trabecular meshwork is reduced. The aqueous humor produced from the ciliary body 83 is gradually accumulated in the eyeball and increases the pressure in the eyeball. There is a causal relationship between the intraocular pressure (hereinafter referred to as intraocular pressure) and the onset of glaucoma. In particular, glaucoma caused by contact between the iris 82 and the trabecular meshwork (TM) or the back of the cornea 80 It is classified as closed angle glaucoma, and it is important to observe the degree of obstruction at the corner angle.

Therefore, an anterior segmental cross-sectional imaging with a function (also referred to as “ITC analysis”) that analyzes the degree of contact between the iris 82 and the trabecular meshwork (TM) or the rear surface of the cornea 80 in a corner examination. Equipment is provided.

In this case, the examiner manually performs sclera on a tomographic image (also referred to as a B-scan image) of a corner area at a plurality of angle meridians obtained by the above-described radial scan displayed on the monitor, for example. Point the position of the cape (SS) and the front of the iris with the trabecular meshwork or the back of the cornea (EP) with the mouse or touch pen, and display the positional relationship between SS and EP in the range of 0 to 360 degrees. The state of the area (closed state) was displayed on a monitor and visually confirmed, and used to diagnose the closed angle. (For example, Non-Patent Document 1)

”Anterior Chamber Angle Imaging with Swept-Source Optical Coherence Tomography: Measured Peripheral Anthropogenic in Pel.”

However, in this conventional analysis method, in order to confirm the positional relationship between SS and EP in the range of 0 to 360 degrees in detail, for example, at 100 or more different angle meridians acquired by the radial scan described above. This operation was very time consuming because the examiner had to manually point the SS and EP positions to the B-scan image.

Further, since the examiner manually points, a correct result cannot be obtained due to a point mistake, and there is a possibility that the diagnosis is wrong. In order to prevent misdiagnosis due to this point mistake, it is necessary to check the correlation between two or more data by conducting an inspection with two or more persons or performing an inspection twice or more as in Non-Patent Document 1. It was.

The present invention solves the above-described problems, and the obtained B-scan image is processed by image analysis or the like, and the corner bottom (AR) located near the SS instead of the above-described SS is used. It replaces the conventional ITC analysis using SS by automatically detecting the position and the position of the EP, obtaining the positional relationship between the AR and the EP over the entire corner (0 to 360 degrees) and displaying it on the monitor. It is an object of the present invention to provide an anterior ocular segment cross-sectional image analysis system and an anterior ocular segment cross-sectional image photographing apparatus capable of realizing corner examination with high accuracy and in a short time.

In order to solve the above-mentioned object, the present invention traces the corneal posterior surface and the front of the iris with respect to the B-scan image of the corner region at a plurality of angle meridians passing through the acquired corneal apex, and the front of the iris is the trabecular meshwork or From the positional relationship between the iris front end point detecting means for determining the position in contact with the corneal posterior surface, the iris rear surface tracing the iris rear surface end point detecting means, and the iris front end point and the iris rear surface end point. analysis and determination means that the corner angle, it is determined whether "open angle" or "closed angle", said Ri by the discrimination means "closed angle" and determine the case, the B- scan image of the corner area a corner bottom detecting means for determining the position of the corner bottom and, if it is determined that the "open angle" by the discriminating means, prior to the Kiniji saturation front endpoints and AR, AR and the iris front trabecular meshwork or contact position between the posterior surface of the cornea the position 置関 clerk (EP) 0 Characterized by comprising a display means for displaying in a range of 360 degrees.

As described above, according to the present invention, since the positions of AR and EP can be automatically detected for each B-scan image, the positions of AR and EP in the range of 0 to 360 degrees. The relationship can be displayed on the monitor in a short time.

Moreover, since the examiner does not manually point as in the past, it is possible to prevent a diagnosis error due to a point mistake, and the examination is performed by two or more examiners as described in Non-Patent Document 1. It does not need to be performed or tested multiple times.

Therefore, it is possible to implement a corner inspection instead of the ITC analysis using the conventional SS with high accuracy and in a short time.

1 illustrates an embodiment of the present invention, and is a diagram illustrating a configuration of an optical system of an anterior ocular segment optical coherence tomography apparatus, which is one of the anterior ocular segment image capturing apparatuses Block diagram schematically showing the electrical configuration of the anterior ocular optical coherence tomography apparatus The flowchart which shows the process sequence of imaging | photography of the tomographic image which a control apparatus performs Diagram for explaining raster scan method in OCT Diagram for explaining the radial scan method in OCT The flowchart which shows the whole process procedure of the corner analysis which concerns on this invention It is an example of a monitor screen before (a) corner angle analysis and (b) after corner angle analysis concerning the present invention. The flowchart which shows the analysis processing procedure of the corner analysis which concerns on this invention The figure explaining the tracing method of the corneal posterior surface and the front of the iris The figure explaining the position detection method of EP_If and EP_Ib, and the method of calculating | requiring the distance D of EP_If and EP_Ib The figure explaining the position detection method of AR at the time of a closed angle The figure explaining the method of calculating the value of D0 It is a figure which shows the schematic structure of an anterior eye part. It is a figure which shows the structure of the corner area | region of the anterior eye part which exists in the rectangular area A of FIG.

An embodiment of the present invention will be described below with reference to FIGS. In this embodiment, an anterior ocular optical coherence tomography apparatus, which is one of the anterior ocular segment image imaging apparatuses, is used. However, the present invention is not limited to the anterior ocular optical coherence tomography apparatus. In addition, any other apparatus capable of taking a cross-sectional image of the anterior segment, such as an ultrasonic diagnostic imaging apparatus using ultrasonic waves, can be used.

FIG. 2 schematically shows an electrical configuration of the anterior ocular optical coherence tomography apparatus 1 according to the present embodiment. The anterior ocular optical coherence tomography apparatus 1 uses the anterior segment Ec of the eyeball (examined eye E) of the subject such as corner angle measurement, corneal curvature, corneal thickness distribution, and measurement of the anterior chamber depth. 1) and is used to take a tomographic image of the anterior segment Ec of the eye E by optical coherence tomography (OCT).

Here, although not shown, the apparatus main body of the anterior ocular optical coherence tomography apparatus 1 moves in the X direction (left and right direction), Y direction (up and down direction), and Z direction (front and back direction) with respect to the holding table. Supported as possible. On the front side (subject side) of the apparatus main body, a chin rest and a forehead support are fixedly provided with respect to the holding table. When the subject places his / her chin on the chin receiving portion and places a forehead on the forehead support portion, the subject's eye (examined eye E) is used for photographing (light of light) provided on the front surface of the apparatus main body. It is arranged in front of the inspection window.

At this time, as shown in FIG. 2, the anterior ocular optical coherence tomography apparatus 1 is configured to freely move the apparatus main body in the X direction, the Y direction, and the Z direction with respect to the holding base. A main body drive unit 2 is provided. Although detailed description is omitted, the main body drive unit 2 has a known configuration including an X-direction movement motor, a Y-direction movement motor, a Z-direction movement motor, and the like, and is controlled by the control device 3. Yes. As will be described later, the main body drive unit 2 and the control device 3 constitute an alignment unit and an auto eye tracking unit together with the alignment optical system 4 and the like.

As shown in FIG. 2, the apparatus main body includes a microcomputer including a CPU, a memory, and the like, and includes a control device 3 that performs overall control, and a tomographic image acquisition unit that acquires a tomographic image of the anterior segment Ec. , An anterior ocular segment imaging system 6 and an alignment optical system 4 constituting imaging means for imaging a front image of the eye E to be examined. The alignment optical system 4 constitutes the alignment means and the auto eye tracking means as described above, and also constitutes the corneal apex position detecting means. Details of the OCT system 5, the anterior ocular segment imaging system 6, and the alignment optical system 4 will be described later.

Further, the apparatus main body is positioned on the rear surface (examiner) side, a monitor 7 as a display device for displaying the front image of the eye to be examined and a key operation unit 8 for the examiner (operator) to perform various operations. Is provided. Although not shown, the key operation unit 8 includes a measurement start switch and the like. In this embodiment, a touch panel 9 that functions as various operation means is provided on the screen of the monitor 7. The control device 3 is connected to a storage unit 10 that stores image data of a captured three-dimensional image.

FIG. 1 shows the configuration of the above-described optical system, that is, the OCT system 5, the anterior ocular segment imaging system 6, and the alignment optical system 4. Hereinafter, these will be described in order. The OCT system 5 obtains a tomographic image (cross-sectional image) of the anterior segment Ec by optical coherence tomography. In this embodiment, a Fourier domain (optical frequency sweep) method using a wavelength scanning light source 11 that scans while changing the wavelength with time is employed.

That is, the light output from the wavelength scanning light source 11 is input to the first fiber coupler 13 through the optical fiber 12a. In the first fiber coupler 13, for example, the reference light and the measurement light are in a ratio of 1:99. Is output after being demultiplexed. Among them, the reference light is input to the input part of the first circulator 14 through the optical fiber 12b, and further output from the input / output part of the first circulator 14 through the optical fiber 12c from the end thereof. And enters the reference mirror 16 through the collimator lens 15.

Then, the reference light reflected by the reference mirror 16 is input again from the end of the optical fiber 12c through the plurality of collimator lenses 15 and input / output unit of the first circulator 14 through the optical fiber 12c. It is input from. The reference light output from the output unit of the first circulator 14 is input to the first input unit of the second fiber coupler 17 through the optical fiber 12d.

On the other hand, the measurement light output from the first fiber coupler 13 is input to the input portion of the second circulator 18 through the optical fiber 12e, and is further input to the optical fiber 12f from the input / output portion of the second circulator 18. And output from that end. The measurement light output from the end of the optical fiber 12 f is input to the galvano scanner 20 through the collimator lens 19. The galvano scanner 20 is for scanning the measurement light, and is driven by a galvano driver 21.

The measurement light output from the galvano scanner 20 is reflected at an angle of 90 degrees by a hot mirror 22 that reflects light having a longer wavelength and transmits light having a shorter wavelength, and is emitted from the inspection window through the objective lens 23. , And enters the eye E to be examined. The measurement light incident on the eye E is reflected by each tissue part (cornea, anterior chamber, iris, lens, etc.) of the anterior segment Ec, and the reflected light is incident from the examination window. Then, the light passes through the objective lens 23, the hot mirror 22, the galvano scanner 20, and the collimator lens 19 in this order, and is input from the end of the optical fiber 12f.
Then, the reflected light is input from the input / output unit of the second circulator 18 through the optical fiber 12f, is output from the output unit of the second circulator 18, and passes through the optical fiber 12g to the second fiber. The signal is input to the second input unit of the coupler 17.

In the second fiber coupler 17, the reflected light from the anterior segment Ec and the reference light input through the optical fiber 12d are combined at a ratio of, for example, 50:50, and the signal is optical fiber. 12h and 12i are input to the detector 24. In the detector 24, the interference for each wavelength is measured, and the measured interference signal is input to the AD board 25 provided in the control device 3. Further, the arithmetic unit 26 provided in the control device 3 performs a process such as Fourier transform on the interference signal, thereby acquiring a tomographic image of the anterior segment Ec along the scanning line.

At this time, as will be described in detail later, the scanning pattern of the measurement light by the galvano scanner 20, in other words, the direction of the scanning line (B-scan) is set in the control device 3. The galvano driver 21 controls the galvano scanner 20 based on a command signal from the control device 3 (calculation unit 26). The obtained tomographic image data of the anterior segment Ec is stored in the storage unit 10 after necessary refraction correction is performed. Further, as schematically shown in FIG. 1, the tomographic image T can be displayed on the monitor 7.

Next, the anterior ocular segment imaging system 6 includes illumination light sources 27 and 27, the objective lens 23, the hot mirror 22, a cold mirror 28, an imaging lens 29, a CCD camera 30, and an optical control unit 31. The The illumination light sources 27, 27 are adapted to irradiate the front of the eye E with illumination light in the visible light region, and reflected light from the eye E is transmitted from the examination window to the objective lens 23, hot mirror 22, The light enters the CCD camera 30 through the cold mirror 28 and the imaging lens 29. Thus, the front image F of the eye E is photographed, and the photographed image data is subjected to image processing by the optical control unit 31 and displayed on the monitor 7.

In more detail, the alignment optical system 4 is a fixation lamp optical system for preventing the eyeball (test eye E) from moving as much as possible when the subject looks at the fixation lamp. XY direction position detection system for detecting the position of the corneal apex) in the XY direction (up / down / left / right position shift with respect to the main body), Z for detecting the front / rear direction (Z direction) position of the eye E (corneal apex) A direction position detection system is included.

The fixation lamp optical system includes a fixation lamp 32, a cold mirror 33, a relay lens 34, a half mirror 35, the cold mirror 28, the hot mirror 22, the objective lens 23, and the like. Thus, the light (for example, green light) output from the fixation lamp 32 passes through the cold mirror 33, the relay lens 34, the half mirror 35, the cold mirror 28, the hot mirror 22, and the lens 23 in this order. Is output toward the eye E to be examined.

The XY direction position detection system includes an XY position detection light source 36, the cold mirror 33, the relay lens 34, the half mirror 35, the cold mirror 28, the hot mirror 22, the objective lens 23, an imaging lens 37, a position. A sensor 38 and the like are provided. The XY position detection light source 36 outputs alignment light for position detection. The alignment light is detected from the inspection window via the cold mirror 33, the relay lens 34, the half mirror 35, the cold mirror 28, the hot mirror 22, and the objective lens 23. The light is emitted toward the anterior eye portion Ec (cornea) of the optometry E.

At this time, the corneal surface of the eye E to be examined has a spherical shape, so that the alignment light is reflected on the corneal surface so as to form a bright spot image inside the corneal apex of the eye E to be examined, and the reflected light is It enters from the inspection window. Reflected light (bright spot) from the corneal apex is input to the position sensor 38 via the objective lens 23, hot mirror 22, cold mirror 28, half mirror 35, and imaging lens 37. When the position of the bright spot is detected by the position sensor 38, the position of the apex of the cornea (the position in the X direction and the Y direction) is detected. The bright spot is also reflected in the image taken by the CCD camera 30 (display image on the monitor 7).

The detection signal of the position sensor 38 is input to the optical control unit 31 and thus to the control device 3. In this case, alignment between the position sensor 38 and the anterior ocular segment imaging system 6 (CCD camera 30 or monitor 7) is taken, and a predetermined (normal) image acquisition position (tomographic image acquisition) of the corneal apex is obtained. The position to be followed at times is set. The normal image acquisition position of the corneal apex is, for example, a point that coincides with the center position of the image captured by the CCD camera 30 (the screen center position of the monitor 7). Based on the detection of the position sensor 38, the control device 3 detects the amount of displacement of the detected corneal vertex (bright spot) in the X and Y directions relative to the normal position (in this case, the position from the screen center of the monitor 7). (Shift amount).

The Z-direction position detection system includes a Z-direction position detection light source 39, an imaging lens 40, and a line sensor 41. The Z-direction position detection light source 39 irradiates the eye E with detection light (slit light or spot light) from an oblique direction, and oblique reflected light from the cornea passes through the imaging lens 40 to form a line. The light is incident on the sensor 41. At this time, since the incident position of the reflected light incident on the line sensor 41 differs depending on the position of the eye E in the front-rear direction (Z direction) with respect to the apparatus body, the position of the eye E in the Z direction with respect to the apparatus body (Distance) is detected.

The detection signal of the line sensor 41 is input to the control device 3. At this time, an appropriate Z-direction position (distance) of the eye E (cornea) with respect to the apparatus main body is set in advance in the control device 3, and an appropriate position of the eye E based on the detection of the line sensor 41. The amount of deviation in the Z direction with respect to can be obtained.

Then, the control device 3 detects the amount of positional deviation in the X and Y directions of the corneal apex (bright spot) detected by the XY position detection system, and the eye E detected by the Z direction position detection system. Based on the amount of misalignment in the Z direction, the main body drive unit 2 is controlled so that all the misalignment amounts are zero, and the apparatus main body is moved relative to the holding base. At this time, when starting the tomographic image acquisition, the control device 3 moves the apparatus main body with respect to the holding table so that the position of the corneal apex coincides with the predetermined image acquisition position. Even during tomographic image acquisition processing, the apparatus main body is moved to follow so that the positional relationship between the corneal apex and the apparatus main body is kept constant. Thus, the alignment means and the auto eye tracking means are configured.

Next, the operation of the anterior ocular optical coherence tomography apparatus 1 configured as described above will be described with reference to FIG. The flowchart in FIG. 3 shows a processing procedure executed by the control device 3 when taking a tomographic image of the anterior segment Ec of the eye E to be examined.

Here, the tomographic image of the anterior eye portion Ec is acquired in a state where the subject places his / her chin on the chin receiving portion, places the forehead on the forehead support portion, and places the subject's eye E in front of the examination window of the apparatus main body. Is started (the anterior ocular segment tomography program is activated), first, in step S1, the current front image of the eye E to be inspected, which is imaged by the anterior ocular segment imaging system 6 (CCD camera 30), The current tomographic image of the anterior segment Ec scanned along the scanning line extending in the horizontal direction at the center of the screen is also displayed on the monitor 7 (see FIG. 2). However, at this time, the data of the front image and the tomographic image are not taken into the memory.

Thereafter, when the examiner turns on the measurement start switch (step S2), alignment in the X, Y, and Z directions by the alignment optical system 4 or the like is started in step S3, and the bright spot for corneal vertex recognition is normal. When the position coincides with (YES in step S4), the alignment is completed. Subsequently, the process proceeds to step S5, and the OCT system 5 executes tomographic image acquisition processing of the anterior segment Ec. During this tomographic image acquisition process, auto eye tracking functions and the alignment optical system 4 or the like is used so that the bright spot for corneal apex recognition always comes to the normal position (the center position of the image taken by the CCD camera 30). The device body is moved following.

In this embodiment, the tomographic image acquisition process in step S5 is performed over the entire region by the radial scan method shown in FIG. That is, the tomographic image is captured with the B-scan direction as the radial direction and the C-scan direction as the circumferential direction. At this time, even if the eye E shifts, the scanning line is shifted from the straight line passing through the corneal apex by maintaining the positional relationship between the apparatus main body and the eye to be kept constant by auto eye tracking. Of course, it can be prevented. In step S6, the acquired (photographed) tomographic image data is taken into the memory.

In the next step S7, refraction correction processing of the data of each tomographic image is performed. In this process, the measurement light is refracted in the substantially spherical cornea (the corneal surface and the interface with the anterior chamber), so that the obtained tomographic image is distorted. Data correction is performed. The image data subjected to the correction process is stored in the storage unit 10.

Next, the procedure of corner angle analysis according to the present invention will be described with reference to the flowchart of FIG. 6 and FIG. Note that the tomographic image described in the following description is a tomographic image (B-scan image) of the anterior segment Ec acquired by the radial scan method as described above.

First, the ITC button displayed on the monitor 7 is pushed by step S10. Then, in step 11, a screen before analysis as shown in FIG. Here, step 12 following step 11 is not an essential step, and the ITC analysis in step 13 may be performed beyond step 11 and step 12 by pressing the ITC button in step S10.

In step 12, the start button 70 in FIG. Then, the ITC analysis in step 13 is performed. The contents of the ITC analysis will be described later.

When step 13 is completed, a screen after analysis as shown in FIG. The acquired B-scan thumbnail image list 71 is displayed on the left side of the screen. When the examiner selects one B-scan image from the thumbnail image list 71, the selected B-scan image is displayed at the upper center of the screen. Displayed, the examiner can confirm the AR position (◯) and the EP position (ten) automatically detected by ITC analysis. In addition, the lower left corner of the screen displays the position of the EP in the entire circumferential direction with the corner base (AR) as the reference circle (72 in the figure), and visually shows the degree of contact between the iris and the trabecular meshwork or the corneal posterior surface. Can be confirmed. Also, on the lower right of the center of the screen, the degree of contact between the iris and the trabecular meshwork or the posterior surface of the cornea in the entire circumferential direction is displayed on the graph (73 in the figure).

Here, the examiner confirms the AR position (◯) and EP position (ten) automatically detected by the ITC analysis displayed on the selected B-scan image at the top center of the screen. If the examiner determines that there is an error in the AR position (○) or the EP position (10), the displayed AR position (○) or EP position ( 10), the change contents are stored in the storage unit 10, and the analysis results of the screens 72 and 73 can be displayed again at the changed AR position (◯) and EP position (10). It is.

Next, the ITC analysis procedure of step 13 as the corner analysis according to the present invention will be described with reference to the flowchart of FIG. 8 and FIGS.

In accordance with the above, the control device 3 selects any one of the B-scan images acquired by the radial scan method, subjected to refraction correction processing, and stored in the storage unit 10. Since only the first B-scan image to start analysis is selected, a B-scan image acquired at a preset angle meridian angle, for example, a B-scan image at an angle meridian of 0 degrees (horizontal line) May be selected.

FIG. 9A is a schematic diagram of a B-scan image of the anterior segment before tracing (before analysis). As shown in FIG. 9B, the control device 3 traces the rear surface of the cornea and the front surface of the iris for the selected B-scan image (step S20). The tracing method is to perform tracing along the corneal posterior surface and the front of the iris simultaneously in both directions from the center of the cornea to the corner bottom (AR) at both ends, and the end where each trace line intersects is defined as the front end point of the iris (EP_If). B—Stores as coordinate point of scanned image. (Step S21, FIG. 10 (a))

Next, as shown in FIG. 9C, the rear surface of the iris is traced simultaneously in both directions from the cornea center to both corner bottoms (AR) as shown in FIG. 9C (step S22), and the end point of the trace line is detected. Then, the position is stored as the iris rear surface end point (EP_Ib) as the coordinate point of the B-scan image. (Step S23, FIG. 10 (a))

A distance D between the position of EP_If and the position of EP_Ib detected in steps S21 and S23 is calculated. (Step S24, FIG. 10B)

When the calculated distance D is within a predetermined value compared with the predetermined value D0, it is determined that the eye to be inspected of the acquired B-scan image is an open angle, and FIG. As shown, the detected EP_If is stored as a corner point (AR) position and an EP position as a coordinate point of a B-scan image. (Step S25, Step 26, Step 29)

If the calculated distance D is larger than the predetermined value D0, it is determined that the eye to be inspected of the acquired B-scan image is a closed angle, and is detected in step 22 as shown in FIG. A perpendicular line is drawn from the iris rear surface end point (EP_Ib) in the direction of the front of the iris, and the intersection of the perpendicular line and the line extended along the trace line of the rear cornea traced in step 21 is detected as the position of the corner base (AR). Together with (Step S27), the position of EP_Ib detected in Step 21 is set as the EP position. (Step S28)

The AR position and EP position obtained in the above steps are stored as coordinate points of the B-scan image. (Step S29)

Here, the predetermined value D0 is obtained and determined by, for example, two methods shown in FIGS. 12 (a) and 12 (b). In the method of FIG. 12A, a perpendicular line is drawn from the EP_If detected in step S21 to the rear surface of the iris, and the length of the perpendicular line to the rear surface of the iris is calculated. In the method of FIG. 12B, the average thickness of the iris part is calculated from the results of tracing the front and rear surfaces of the iris in step 21 and step 22. When the values obtained by the two methods shown in FIGS. 12A and 12B are compared, and the difference between the two values obtained is large, the smaller value is set to D0. If the difference between the two values is small The average value of the two values may be set as D0. Further, the average value of the values of D0 calculated in the method of FIG. 12A or the values of D0 in all B-scan images may be set as D0.

Further, in step 27, since the adhesion portion between the front of the iris and the trabecular meshwork or the posterior cornea is displayed in a white line, if it is determined that the angle is a closed angle, the iris rear surface endpoint (EP_Ib) detected in step 22 is determined. ) Along the white line, and the end point may be stored as the position of the corner bottom (AR) and stored as the coordinate point of the B-scan image.

Further, since the position of the scleral cape (SS) is a predetermined distance (usually 200 μm) from the corner bottom (AR) along the posterior surface of the cornea to the central direction of the cornea, the corneal posterior surface is detected from the AR detected by the above method. A position at a predetermined distance (usually 200 μm) along the trace line may be stored as the SS position as a coordinate point of the B-scan image.

Thus, when the position of SS is specified based on AR detected by the said method, you may employ | adopt SS calculated | required by the above-mentioned method instead of detected AR.

The processing from step 20 to step 29 is performed on all the B-scan images obtained, and the EP coordinate point and the AR coordinate point in each B-scan image are the values of the meridian angles of the B-scan image. In addition, it is stored in the storage unit 10.

When the above processing is completed, the corner angle displayed at the lower center of the screen of FIG. 7B from the positions of the AR and EP coordinate points in the B-scan image for all meridian angles stored in the storage 10. A graph (73 in the figure) of the position of the EP in the circumferential direction with reference to the base (AR) (72 in the figure) and the degree of contact between the iris and the trabecular meshwork or the posterior cornea in the circumferential direction in the circumferential direction. Thus, the degree of contact between the iris and the trabecular meshwork or the posterior surface of the cornea can be visually confirmed.

The embodiments of the present invention have been described in detail above. However, these are merely examples, and the present invention is not construed as being limited by specific descriptions in the embodiments. The present invention can be carried out in a mode in which various changes, modifications, improvements, etc. are added based on the knowledge, and such a mode is within the scope of the present invention as long as it does not depart from the gist of the present invention. It should be understood that it is included in.

As described above, according to the present embodiment, as described above, AR and EP are automatically detected to perform corner inspection instead of ITC analysis using the conventional SS with high accuracy and in a short time. This is possible.

1..Anterior optical coherence tomography apparatus 2..Wavelength scanning light source 3..Control device (scan line setting means) 4..Alignment optical system (corneal apex position detecting means, alignment means, auto eye tracking means) 5 .. OCT system (tomographic image acquisition means) 6 .. Anterior eye imaging system (imaging means) 7 .. Monitor (display device) 9 .. Touch panel (designating means) E .. Eye Ec to be examined.

Claims (3)

For the B-scan image of the corner area at a plurality of angle meridians passing through the acquired corneal apex, the posterior cornea and the front of the iris are traced to determine the position where the front of the iris contacts the trabecular meshwork or the posterior cornea Detection means;
An iris rear surface end point detecting means for tracing the iris rear surface and obtaining an end point of the iris rear surface;
A discriminating means for discriminating whether the corner angle is “open corner angle” or “closed corner angle” from the positional relationship between the iris front end point and the iris rear end point;
A corner bottom detection means for analyzing the B-scan image of the corner area to determine the position of the corner bottom when the discrimination means determines that the angle is a closed angle;
If it is determined that the "open angle" by the discriminating means, the iris front end point and AR, AR and scope positional relationship of 0 to 360 ° of the iris front contact position between the trabecular meshwork or posterior surface of the cornea (EP) Display means for displaying with,
An anterior ocular segment cross-sectional image analysis apparatus comprising:   The corner bottom detecting means detects, as a corner bottom, an intersection of a perpendicular line from the iris rear surface end point detected by the iris rear surface end point detecting means to the front surface of the iris and an extension line of the trace line on the rear cornea. The anterior segment cross-sectional image analysis apparatus according to claim 1.   2. The corner-bottom detection means traces along a white line appearing at a portion where the trabecular meshwork or the posterior cornea and the front of the iris are adhered, and detects the end point as a corner-bottom. Anterior segment cross-sectional image analysis device.