JP2022013342A - Fundus imaging apparatus - Google Patents

Abstract

To provide a fundus imaging apparatus which can efficiently image a subject eye.SOLUTION: A fundus imaging apparatus which has an OCT optical system for detecting an interference signal with measurement light irradiated to the fundus oculi of a subject eye and reference light and acquires OCT data of the fundus oculi on the basis of the interference signal comprises: observation image acquisition means which acquires an observation image of a fundus oculi; and control means which executes guidance processing for guiding a yellow portion and a papillary portion included in the observation image into an imaging range of the OCT data imaged by the OCT optical system and for aligning an analysis object including at least any of the yellow portion and the papillary portion with a proper position set within the imaging range in consideration of a region size necessary for analysis of the analysis object.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a fundus photography apparatus that acquires OCT data of the fundus of an eye to be inspected.

A composite fundus photography device equipped with an optical coherence tomography (OCT) configuration and a fundus camera optical system configuration is known. For example, in Patent Document 1, it is possible to acquire wide-area OCT data in which both the macula of the fundus and the papilla are photographed.

JP-A-2015-104581

By the way, such wide-area OCT data may be obtained as an image in which at least one of the macula and the papilla is not included (or a part is missing). Since these are inappropriate for analysis and diagnosis, it was necessary to take another picture.

In view of the above-mentioned prior art, it is a technical subject of the present disclosure to provide a fundus photography apparatus capable of efficiently advancing the imaging of the eye to be inspected.

In order to solve the above problems, the present disclosure is characterized by having the following configurations.

The fundus photography apparatus of the present disclosure has an OCT optical system for detecting an interference signal due to a measurement light radiated to the fundus of an eye to be inspected and a reference light, and based on the interference signal, the OCT data of the fundus is obtained. An observation image acquisition means for acquiring an observation image of the fundus, and an imaging range of the OCT data in which the yellow spot and the papilla included in the observation image are photographed by the OCT optical system. It is a guidance process for guiding inward, and is set within the imaging range in consideration of the analysis target including at least one of the yellow spot and the papilla and the area size required for the analysis of the analysis target. It is characterized by comprising a control means for executing a guidance process for matching the appropriate position.

It is an external view of the OCT apparatus. It is a schematic diagram of the inside in a photographing part. This is an example of a frontal observation image. This is an example of an appropriate position in a frontal observation image. This is an example of a frontal observation image. This is an example of a frontal observation image. This is an example of an OCT tomographic image.

<Overview>
An embodiment of the ophthalmologic imaging apparatus according to the present disclosure will be described. Items classified by <> below may be used independently or in relation to each other.

The fundus photography device of the present embodiment is an OCT device having a configuration of an optical coherence tomography. For example, the fundus photography apparatus has an OCT optical system that detects an interference signal due to a measurement light radiated to the fundus of the eye to be inspected and a reference light, and acquires OCT data of the fundus based on the interference signal. The fundus photography device may further have a fundus camera configuration (fundus camera optical system) and acquire a fundus image. Further, the fundus photography apparatus may further have a configuration of a scanning laser ophthalmoscope (SLO optical system) and acquire an SLO front image.

<Observation image acquisition means>
The fundus photography apparatus of this embodiment may include an observation image acquisition means (for example, a control unit 300). The observation image acquisition means acquires an observation image (fundus observation image) of the fundus in the eye to be inspected. The observation image acquisition means may acquire OCT data captured by the OCT optical system as a fundus observation image. In this case, as the OCT data, a two-dimensional OCT tomographic image may be acquired, a three-dimensional OCT tomographic image may be acquired, or an OCT frontal image based on the three-dimensional OCT tomographic image may be acquired. .. Further, the observation image acquisition means may acquire a fundus observation image taken by the fundus camera optical system. In this case, an infrared fundus image by infrared light may be acquired. Further, the observation image acquisition means may acquire a fundus observation image (that is, an SLO front image) taken by the SLO optical system.

<Detection means>
The fundus photography apparatus of this embodiment may include a detection means (for example, a control unit 300). The detection means detects an analysis target including at least one of the macula and the papilla from the fundus observation image acquired by the observation image acquisition means. The detection means may detect the analysis target by using various image processing methods. As an example, a feature point extraction method, a method using a correlation function, a method using a Fourier transform, or the like may be used.

The detection means may directly detect the analysis target such as the macula, the papilla, and the like. For example, the detection means may detect the analysis target by using the organizational features (for example, shape, brightness, etc.) of the analysis target stored in advance in the storage unit. Further, for example, the detection means may detect a blood vessel or the like and indirectly detect an analysis target such as a macula, a papilla, etc. based on the detection result. As an example, the position of the macula or the papilla may be predicted and detected from the extension direction of the blood vessel. Further, for example, the detection means may predict and detect the position of the macula or the papilla by using the left and right eye information.

<Adjustment means>
The fundus photography device of the present embodiment may be provided with adjusting means. The adjusting means adjusts the imaging range of the OCT data captured by the OCT optical system. For example, the adjusting means may be a scanning means (for example, an optical scanner 234) that scans the measurement light in the OCT optical system. Further, for example, the adjusting means may be a light source (for example, a fixed vision lamp) for gazing at the line of sight of the eye to be inspected. Further, for example, the adjusting means may be a driving means for driving the photographing means (for example, the photographing unit 200) with respect to the eye to be inspected. As an example, it may be a driving means (for example, a driving unit 105) for moving the photographing means in the left-right direction, the up-down direction, and the front-back direction with respect to the eye to be inspected. Further, as an example, it may be a driving means for tilting (turning) the photographing means in the left-right direction and the up-down direction with respect to the eye to be inspected.

<Setting means>
The fundus photography device of the present embodiment may include a setting means (for example, a control unit 300). The setting means include a first imaging mode for acquiring the first OCT data in which either the macula or the papilla is photographed, a second imaging mode in which the second OCT data in which both the macula and the papilla are imaged are acquired, and the second imaging mode. Can be set. For example, the setting means may set either the first shooting mode or the second shooting mode based on the signal input by the operator operating the operating means (for example, the monitor 104). Further, for example, the setting means may set either the first photographing mode or the second photographing mode based on the photographing program for photographing the eye to be inspected.

<Control means>
The fundus photography device of the present embodiment may include a control unit (for example, a control unit 300). The control unit is a guidance process for guiding the macula and the papilla included in the fundus observation image into the imaging range of the OCT data captured by the OCT optical system, and aligns the analysis target with the appropriate position. Perform guidance processing for. The analysis target may be at least one of the macula and the papilla. Further, the appropriate position may be a position set within the photographing range in consideration of the area size required for the analysis of the analysis target. As a result, the imaging of the eye to be inspected is efficiently advanced, and the possibility of re-imaging due to the fact that the macula and the nipple are not included in the imaging range is reduced.

The area size required for the analysis of the analysis target may be changed according to the analysis content of the OCT data. That is, the appropriate position may be changed according to the analysis content of the OCT data. For example, the proper position may be set to a position where the macula or the papilla is predicted to be located. In this case, the appropriate position may be set to a position predicted (stored) based on the results of an experiment, simulation, or the like. Further, in this case, the appropriate position may be set to a position predicted based on the axial length different for each eye to be inspected acquired in advance. Further, for example, the appropriate position may be set based on the detection result of the detection means. In this case, the appropriate position may be set to the position of the macula or the papilla detected from the fundus observation image. Further, in this case, the appropriate position may be set to a position separated by a predetermined distance from the macula or the papilla detected from the fundus observation image.

The control unit may output guide information for guiding the analysis target to an appropriate position as a guidance process. For example, by using the guide information, the deviation between the analysis target and the target position can be eliminated, and the analysis target can be easily adjusted to the appropriate position.

For example, the control unit may control the display means and cause the display means to display the guide information. Further, for example, the control unit may control the voice generating means (for example, a speaker) and generate the guide information as voice in the voice generating means. Further, for example, the control unit may control the notification means (for example, a lamp) and display the guide information by lighting or blinking the notification means. The control unit may execute a control in which these are combined, or may execute a control different from these.

The guide information may be information for guiding the movement of the examiner. For example, the examiner is urged to change the position of the fixation lamp that gazes at the line of sight of the subject, move the photographing means (for example, the photographing unit 200) with respect to the subject, adjust the inclination and position of the subject's face, and the like. Information for. Further, the guide information may be information for guiding the movement of the subject. For example, information for encouraging the subject to move the line of sight (for example, generation of a voice indicating that the line of sight is moved) may be mentioned. Further, the guide information may be information indicating at least one of the movement amount and the movement direction of the fixation lamp. Further, the guide information may be information indicating at least one of the moving amount and the moving direction of the photographing means. Of course, the guide information may be a combination of these information, or may be information different from these information.

Based on the detection result of the detection means, the control unit may output guide information for guiding the analysis target including at least one of the macula and the papilla to an appropriate position as the guidance process. That is, the control unit may control at least one of the display means, the voice generation means, the notification means, and the like based on the detection result of the detection means to output the guide information. As a result, the deviation between the macula and the nipple and the proper position is easily eliminated, and the macula and the nipple can be easily adjusted to the proper position.

As a guidance process, the control unit may superimpose and display an index representing the target position for matching the analysis target with the appropriate position on the fundus observation image. In this case, the control unit may control the display of the display means (for example, the monitor 104) and display an index indicating the target position of the macula at a predetermined position corresponding to the appropriate position of the macula. Further, in this case, the control unit may control the display of the display means and display an index indicating the target position of the papilla at a predetermined position corresponding to the appropriate position of the papilla. That is, such an index may be used as the above-mentioned guide information. Of course, the control unit may display such an index and output the above-mentioned guide information. As a result, the deviation between the macula or the nipple and the target position can be grasped, and the macula or the nipple can be easily adjusted to the appropriate position.

The size of the index displayed on the display means may be changed according to the analysis content for analyzing the OCT data. For example, the larger the display size of the index, the wider the permissible range for matching the analysis target with the appropriate position. Further, for example, the smaller the display size of the index, the narrower the permissible range for matching the analysis target with the appropriate position. That is, an index corresponding to a different permissible range may be displayed for each analysis content of the OCT data.

The control unit may control the adjusting means and adjust the imaging range as the guidance process in order to guide the analysis target into the imaging range of the OCT data captured by the OCT optical system. For example, the control unit may adjust the imaging range of the OCT data by controlling the scanning means for scanning the measurement light in the OCT optical system and automatically adjusting the scanning conditions of the measurement light. Further, for example, the control unit controls the light source (fixed-view lamp) to automatically change the lighting and extinguishing of the light source and the lighting position of the light source to change the line-of-sight direction of the eye to be inspected and perform OCT. The shooting range of the data may be adjusted. Further, for example, the control unit controls the driving means for moving or tilting the photographing means with respect to the eye to be inspected, and automatically adjusts the relative positional relationship between the eye to be inspected and the photographing means to perform OCT. The shooting range of the data may be adjusted. By controlling at least one of these, the analysis target is automatically placed within the imaging range of the OCT data, and as a result, the deviation between the analysis target and the target position is eliminated, and each part is appropriately placed within the imaging range. Be placed.

In addition, the control unit may execute each guidance process so as to match the papilla as the analysis target and the appropriate position considering the region size required for the analysis of the papilla. That is, the control unit may output guide information for guiding the nipple to an appropriate position. In addition, the control unit may superimpose and display an index representing a target position for matching the papilla to an appropriate position on the fundus observation image. Further, the control unit may control the adjusting means in order to guide the papilla into the imaging range of the OCT data imaged by the OCT optical system.

When the second shooting mode is set by the setting means, the control unit may execute a guidance process for aligning the analysis target with the appropriate position. For example, in the second imaging mode in which the macula and the nipple are imaged at the same time, both the macula and the nipple must be kept within a predetermined imaging range, and these areas are not included (or part of them). It tends to be in a chipped state. Therefore, especially in the second imaging mode, the guidance process for aligning the analysis target with the appropriate position is effective in improving the efficiency of imaging of the eye to be inspected.

Of course, the control unit may execute the guidance process for aligning the analysis target with the appropriate position even when the first shooting mode is set by the setting means. More specifically, when the macula is photographed in the first imaging mode, an induction process for aligning the macula with an appropriate position may be executed. Further, when photographing the papilla in the first imaging mode, a guidance process for aligning the papilla with an appropriate position may be executed.

The fundus imaging device of the present embodiment may be a composite device including an OCT optical system and a fundus camera optical system. In the composite device, the scanning range (that is, the photographing range) of the measured light in the OCT optical system is limited to the photographing range in the fundus camera optical system. Generally, the angle of view is limited to 40 ° to 45 °. Therefore, when the line of sight of the eye to be inspected is directed toward the front, the macula is located in the center of the fundus observation image, and the papilla is located around the fundus observation image. Since the positional relationship between the macula and the nipple is different for each eye to be inspected, a part of the nipple may be missing from the image.

For example, by guiding the line of sight of the eye to be inspected by moving the position of the fixation lamp and arranging the space between the macula and the nipple in the center of the fundus observation image, the macula and the nipple can be included in the fundus observation image. Will be done. However, if the line of sight of the eye to be inspected is not guided well, or if the movement of the fixation lamp position is not sufficient due to the positional relationship between the macula and the papilla, appropriate OCT data cannot be obtained.

Therefore, the control means executes the guidance process as described above, guides the macula and the papilla included in the fundus observation image into the imaging range of the OCT data captured by the OCT optical system, and sets the analysis target. Align with the proper position. For example, in this state, appropriate OCT data can be obtained by scanning the measurement light in the OCT optical system with a predetermined scanning pattern (for example, raster scan or the like). As a result, the image of the eye to be inspected is efficiently photographed, and the possibility of re-imaging is reduced.

<Example>
An embodiment of the fundus photography apparatus in this embodiment will be described. The fundus photography device may be an OCT device having a configuration of a so-called optical coherence tomography. The OCT apparatus may have a time domain OCT as a basic configuration. Further, the OCT apparatus may have a Fourier domain OCT as a basic configuration. The Fourier domain OCT may be a spectral domain OCT, a wavelength sweep type OCT, or the like.

FIG. 1 is an external view of the OCT device 1. The OCT device 1 includes a base 101, a moving table 102, an operation unit 103, a monitor 104, a drive unit 105, a detection unit 106, a face support unit 110, an imaging unit 200, a control unit 300, and the like.

The operation unit 103 inputs a signal for operating the photographing unit 200. For example, when the operation unit 103 is tilted, a movement signal for moving the moving table 102 in at least one of the left-right direction (X direction) and the front-back direction (Z direction) is input to the base 101. .. Further, for example, when the knob (not shown) of the operation unit 103 is rotated, a movement signal for moving the photographing unit 200 in the vertical direction (Y direction) is input to the base 101.

The monitor 104 displays the OCT data of the eye E to be inspected, the analysis result of the OCT data, and the like on the screen. For example, the OCT data may be an OCT tomographic image, an OCT frontal image, or the like. For example, the analysis result of the OCT data may be a network thickness information, a network film thickness map image generated based on the network film thickness information, an analysis chart calculated based on the network film thickness information, or the like. Further, the monitor 104 functions as a touch panel that also serves as an operation unit 103. That is, a movement signal for moving the photographing unit 200 is also input by operating the monitor 104.

The drive unit 105 moves the photographing unit 200 in the left-right direction, the up-down direction, and the front-back direction. For example, the drive unit 105 is a slide mechanism. As an example, the slide mechanism may include a motor, gears, guide rails, and the like.

The detection unit 106 detects the position of the photographing unit 200. For example, the detection unit 106 is a variable resistor. Of course, the detection unit 106 is not limited to the variable resistor, and may be at least one of an optical sensor, a position sensor, a distance sensor, and the like. The detection result of the detection unit 106 is output to the control unit 300.

The face support portion 110 supports the face of the subject. The face support portion 110 has a forehead pad 111 and a chin rest 112. The forehead of the subject is brought into contact with the forehead pad 111. The chin of the subject is placed on the chin rest 112. The chin stand 112 is provided with a detector 113.

The detector 113 detects whether or not the subject's jaw is placed on the jaw stand 112. For example, the detector 113 is a load sensor. Of course, the detector 113 is not limited to the load sensor, and may be at least one of an optical sensor, a pressure sensor, an ultrasonic sensor, and the like. The detection result of the detector 113 is output to the control unit 300.

<Shooting department>
FIG. 2 is a schematic view of the inside of the photographing unit 200. The alignment index projection optical system 210, the anterior segment imaging optical system 220, the OCT optical system 230, the observation optical system 240, the fixation induction optical system 250, the face imaging optical system 260, and the like are housed inside the photographing unit 200. The optical system.

<Alignment index projection optical system>
The alignment index projection optical system 210 projects an alignment index toward the cornea of the eye E to be inspected. The alignment index projection optical system 210 includes a first projection optical system 210a and a second projection optical system 210b. The first projection optical system 210a projects an alignment index at infinity toward the cornea of the eye E to be infinity. The first projection optical system 210a includes a light source 211, a collimator lens 212, and the like. For example, the light source 211 emits near-infrared light. For example, the light source 211 is arranged in a ring shape about the shooting optical axis. For example, the collimator lens 212 makes the light from the light source 211 a parallel luminous flux. The second projection optical system 210b projects an alignment index at a finite distance toward the cornea of the eye E to be inspected. The second projection optical system 210b includes a light source 213 and the like. For example, the light source 213 emits near-infrared light. For example, the light source 213 is arranged in a ring shape around the shooting optical axis at a position different from that of the light source 211. The light from the second projection optical system 210b is used as alignment light for aligning the imaging unit with respect to the eye to be inspected E, and is also used as illumination light for the anterior eye portion to illuminate the anterior eye portion of the eye to be inspected E. Is also used.

<Optical photography system for the anterior segment of the eye>
The anterior segment photographing optical system 220 images the anterior segment of the eye to be inspected E. The front eye photographing optical system 220 includes an image pickup element 221 and the like. For example, the image sensor 221 images the front eye portion illuminated by the light source 213. The image pickup device 221 also serves as an image pickup element for detecting the alignment index projected on the cornea, and images the alignment index together with the anterior eye portion.

<OCT optical system>
The OCT optical system 230 detects an interference signal due to the measurement light and the reference light applied to the eye E to be inspected. The OCT optical system 230 includes a coupler 231, a light source 232, a measurement optical system 233, an optical scanner 234, an objective optical system 235, a detector 236, a reference optical system 237, and the like. A light source 232, a measuring optical system 233, a detector 236, and a reference optical system 237 are connected to the coupler 231 by an optical fiber.

The OCT optical system 230 divides the light emitted from the light source 232 into the measurement light and the reference light by the coupler 231. For example, the measurement light is emitted into the air after passing through the optical fiber and is guided to the fundus of the eye via the measurement optical system 233, the optical scanner 234, and the objective optical system 235. Further, for example, when the measurement light is reflected by the fundus, it is returned to the optical fiber via the same path. For example, the reference light passes through the optical fiber and is guided to the reference optical system 237. Further, for example, when the reference light is reflected by the reference mirror (not shown) included in the reference optical system 237, it is returned to the optical fiber via the same path. The OCT optical system 230 causes the detector 236 to receive an interference signal (interference light) due to the synthesis of the measurement light and the reference light. The interference signal detected by the detector 236 is transmitted to the control unit 300.

<Observation optical system>
The observation optical system 240 is used as a fundus camera optical system, and acquires a fundus image by photographing the fundus. For example, the observation optical system 240 acquires an infrared fundus image by infrared light and a color fundus image by visible light. Further, for example, the observation optical system 240 captures a fluorescent fundus image with a predetermined excitation light. The observation optical system 240 has a structure of a scanning laser ophthalmoscope (SLO), and may acquire an SLO front image of the fundus.

<Fixed vision induction optical system>
The fixation-guided optical system 250 guides the line-of-sight direction of the eye E to be inspected. The fixation-guided optical system 250 has a fixation lamp presented to the eye E to be inspected. For example, the fixation lamp is arranged on the measurement optical axis L and on the same circumference around the measurement optical axis L. By changing the presentation position of the fixation lamp two-dimensionally, the line of sight of the eye E to be inspected is guided in a plurality of directions, and as a result, the imaging portion of the eye E to be inspected is changed.

<Control unit>
The control unit 300 is a processing device (processor) having an electronic circuit that performs control processing and arithmetic processing of each unit. The control unit 300 includes a general CPU (Central Processing Unit), RAM, ROM, and the like. For example, the CPU controls each member in the OCT device 1. For example, RAM temporarily stores various types of information. For example, various programs for controlling the operation of the fundus photography device 1 are stored in the ROM. For convenience, the control unit 300 shall perform image processing of various images obtained by the fundus photography device 1. In other words, the control unit 300 also serves as an image processing unit.

An operation unit 103, a monitor 104, a drive unit 105, a detection unit 106, a light source and an image pickup element included in each optical system, a storage unit 301, and the like are electrically connected to the control unit 300. The storage unit 301 may be a non-transient storage medium capable of retaining the storage contents even when the power supply is cut off. For example, the storage unit 301 may be a hard disk drive, a flash ROM, a USB memory, or the like. For example, the storage unit 301 may store information related to the setting for obtaining OCT data, OCT data obtained by processing the interference signal detected by the detector 236, and the like.

<Control operation>
The control operation of the fundus photography device 1 will be described.

<Alignment adjustment between the eye to be inspected and the imaging part>
The examiner instructs the subject to put his / her face on the face support portion 110. The control unit 300 may detect that the subject's face is placed on the chin rest 112 and automatically start the alignment adjustment between the eye E to be examined and the imaging unit 200.

The control unit 300 controls the fixation-guided optical system 250 and turns on the fixation lamp for gazing at the line of sight of the eye E to be inspected. Further, the control unit 300 controls the alignment index projection optical system 210, turns on the light source 211 and the light source 213, and projects the alignment index onto the cornea of the eye E to be inspected. Further, the control unit 300 controls the anterior eye portion photographing optical system 220 and photographs the eye to be inspected E by the image pickup element 221. As a result, an anterior ocular segment observation image including an alignment index image of the eye E to be inspected is obtained and displayed on the monitor 104.

The control unit 300 detects the direction and amount of deviation between the apex of the cornea of the eye E to be inspected and the measurement optical axis L of the OCT optical system 230 by using the alignment index image. Further, the control unit 300 eliminates the deviation by moving the imaging unit 200 with respect to the eye E to be inspected, and makes the apex of the cornea and the measurement optical axis L coincide with each other.

<Setting shooting mode and scanning conditions>
The examiner sets the imaging mode of the eye E to be inspected and the scanning conditions of the measurement light. The examiner operates the monitor 104 and operates the selection switch for selecting the shooting mode. For example, one of a macular imaging mode for photographing the macula of the fundus, a papillary imaging mode for photographing the papilla of the fundus, and a retinal imaging mode for photographing both the macula and the papilla is selected. The control unit 300 sets the scanning conditions of the measurement light according to the selected shooting mode. For example, at least one of a scanning position (shooting position), a scanning portion (shooting portion), a scanning pattern, and the like is set as scanning conditions. In this embodiment, by selecting the retinal imaging mode, a raster scan in a region of 9 mm in length × 12 mm in width in which the macula and the papilla are photographed is set.

<Acquisition of observation image>
The examiner takes an image of the eye E to be inspected and acquires an observation image of the fundus. For example, as the observation image of the eye E to be inspected, either a three-dimensional OCT tomographic image or an OCT frontal image based on the three-dimensional OCT tomographic image may be selectable. In this embodiment, the OCT front image is selected as the observation image.

The examiner operates the monitor 104 and operates the start switch for starting the observation of the eye E to be inspected. The control unit 300 turns on the fixation lamp on the measurement optical axis L in order to direct the line of sight of the eye E to be inspected toward the front. Further, the control unit 300 controls the OCT optical system 230, and each optical member (for example, a reference mirror (not shown) included in the OCT optical system 230 is set in advance so that the fundus of the eye to be inspected E is photographed. Place it in the correct position. Further, for example, the control unit 300 integrates the spectral intensities of the interference signals detected by scanning the measurement light. As a result, an OCT front image (hereinafter referred to as a front observation image 400) as an observation image is obtained and displayed on the monitor 104.

<Display of nipple target index>
FIG. 3 is an example of the front observation image 400. In this embodiment, since the line of sight of the eye E to be inspected is in the front direction, the macula portion m is located in the center of the front observation image 400. The control unit 300 electrically superimposes and displays the photographing range 401, the fixation lamp position 402, the papilla target index 403, and the like on the front observation image 400. The photographing range 401 represents the scanning range of the measured light by the OCT optical system 230. The size and shape of the shooting range 401 are changed based on the set scanning pattern. The fixation lamp position 402 represents the position of the fixation lamp presented to the eye E to be inspected. For example, if it is a fixation lamp arranged on the measurement optical axis L, it is displayed at the center position C of the front observation image 400 (FIG. 3). For example, if the fixation lamps are arranged on the same circumference about the measurement optical axis L, they are displayed around the center position C. The papilla target index 403 represents a target position for moving the papilla t included in the frontal observation image 400.

Here, the fundus photography apparatus 1 obtains an OCT front image (hereinafter referred to as a front image) as a photographed image based on a three-dimensional OCT tomographic image obtained (captured) of the eye E to be inspected. Further, an analysis result obtained by analyzing the retinal thickness of the fundus based on the three-dimensional OCT tomographic image is obtained, and a retinal thickness map image in which the retinal thickness is two-dimensionally color-coded is generated. In this embodiment, by keeping the macula m and the nipple t within the imaging range 401 of the frontal image, the analysis results for the macula m and the nipple t can be obtained, and the macula m and the nipple t can be obtained. A retinal map image containing and is generated.

FIG. 4 is an example of an appropriate position (appropriate range) of a feature portion in the front observation image 400. The control unit 300 sets an appropriate position within the imaging range 401 in consideration of the size of the analysis area required for analysis of the characteristic portion. The analysis area set by the control unit 300 is stored in the storage unit 301 in advance. For example, in the front observation image 400, the region where the macula portion m is predicted to be located is stored as the analysis region of the macula portion m. As an example, one region obtained by dividing the front observation image 400 into two in the left-right direction is stored as an analysis region of the macula portion m. The control unit 300 sets the analysis region of the macula portion m as an appropriate position R1 in which the macula portion is arranged. The proper position R1 is analyzed by a predetermined method suitable for the analysis of the macula m. Further, for example, in the front observation image 400, the region where the papilla t is predicted to be located is stored as the analysis region of the papilla t. As an example, the other region obtained by dividing the front observation image 400 into two in the left-right direction is set as the analysis region of the papilla t. The control unit 300 sets such an analysis region of the papilla t as an appropriate position R2 in which the papilla is arranged. The proper position R2 is analyzed by a predetermined method suitable for the analysis of the papilla t.

The number of divisions of such analysis regions may be different, or the number of regions to be analyzed may be different. Further, such analysis regions may have different domain sizes from each other. Further, such an analysis area may be partially overlapped. That is, a part of the analysis region (appropriate position R1) of the macula portion m and the analysis region (appropriate position R2) of the papilla t may overlap.

However, in the front observation image 400, if at least a part of the macula m and the papilla t is out of the imaging range 401, the macula m and the papilla t are not located at appropriate positions, and an appropriate analysis result is obtained. Can no longer be obtained. For example, when the measurement light is scanned by the OCT optical system in a region of 9 mm in length × 12 mm in width and the yellow spot m is located in the center of the frontal observation image 400, a part of the papilla t around the frontal observation image 400 is photographed. It may be out of range 401.

Therefore, the control unit 300 superimposes and displays an index representing a target position for moving the feature portion to an appropriate position on the front observation image 400. In this embodiment, the nipple target index 403 for moving the nipple t is superimposed and displayed at the position corresponding to the appropriate position R2. By matching (substantially matching) the nipple t and the nipple target index 403, the macula m and the nipple t can be placed in the imaging range 401, and the macula m and the nipple t can be placed at their respective appropriate positions. can.

<Alignment of nipple and nipple target index>
FIG. 5 is an example of the front observation image 400. The examiner matches the teat t in the frontal observation image 400 with the teat target index 403. For example, the subject may be instructed to change the angle of the subject's face or the direction of the line of sight of the subject E. Further, for example, the lighting of the fixation lamp arranged on the measurement optical axis L is switched to the lighting of the fixation lamp arranged on the same circumference centering on the measurement optical axis L, and the line-of-sight direction of the eye E to be inspected. May be changed. Further, for example, the operation unit 103 may be operated to move the photographing unit 200. As a result, the papilla t is guided within the photographing range 401 of the front observation image 400, and the papilla t is arranged within the appropriate position R2. At the same time, the macula m is also guided in the photographing range 401, and the macula m is arranged in the appropriate position R1.

At this time, the control unit 300 detects the papilla t of the frontal observation image 400 by image processing (for example, a feature point extraction method), and determines whether or not the papilla t and the papilla target index 403 match. The determination result may be notified. For example, the control unit 300 may calculate the brightness in the front observation image 400 and detect a portion substantially matching the brightness of the papilla stored in the storage unit 301 in advance as the papilla t. Further, for example, the control unit 300 may determine whether or not they match based on the amount of deviation between the detected papilla t and the papilla target position 403. For example, the control unit 300 may change the display color of the nipple target index 403 when the nipple t and the nipple target index 403 match. Of course, a message indicating that the nipple t and the nipple target index 403 match may be generated as voice or displayed on the monitor 104.

<Acquisition of captured images>
The examiner operates the monitor 104 and operates the start switch for starting the imaging of the eye E to be inspected. The control unit 300 controls the OCT optical system 230 to optimize the imaging conditions of the fundus in the eye E to be inspected. For example, the optical path length adjustment, the focus adjustment, the polarizer adjustment, and the like are performed so that the desired characteristic portion (here, the macula m and the papilla t) can be photographed with high sensitivity and high resolution. Further, the control unit 300 controls the OCT optical system 230 and scans the measurement light based on the scanning pattern to acquire a three-dimensional OCT tomographic image of the fundus.

<Analysis of captured images>
The three-dimensional OCT tomographic image is obtained as an image including both the macula and the papilla t by taking the papilla t in accordance with the papilla target index 403 as described above. The control unit 300 may detect the macula m from the appropriate position R1 in the three-dimensional OCT tomographic image and calculate the analysis value of the net film thickness with respect to the macula m. Similarly, in the three-dimensional OCT tomographic image, the papilla t may be detected from the appropriate position R2 and the analysis value of the net film thickness with respect to the papilla t may be calculated. For example, the analysis value may be a value obtained by obtaining a basic statistic for each section. For example, the basic statistic may be a representative value (mean value, median value, mode value, maximum value, minimum value, etc.), dispersal degree (variance, standard deviation, coefficient of variation, etc.) and the like. Further, the control unit 300 may generate a retinal map image showing the distribution of the network thickness of the macula m and the papilla t based on the three-dimensional OCT tomographic image. Further, the control unit 300 may generate a frontal image obtained by integrating the spectral intensities of the interference signals at each point in the XY directions based on the three-dimensional OCT tomographic image. The control unit 300 may store a three-dimensional OCT tomographic image, an analysis value, a retinal map image, a frontal image, and the like in the storage unit 301.

Of course, the control unit 300 may perform an analysis to obtain information different from the network thickness of the macula portion m and the papilla portion t. For example, analysis may be performed to obtain information on the shapes of the macula m and the papilla t. In this case, the analysis value of the shape for at least one of the macula m and the papilla t may be calculated based on the three-dimensional OCT tomographic image. As an example, at least one of area, volume, size, analysis parameters (C / D ratio of papilla t, etc.), etc. may be calculated.

As described above, for example, the fundus photography apparatus in this embodiment acquires an observation image of the fundus and analyzes an analysis target including at least one of the macula and the papilla included in the observation image by using an OCT optical system. It is a guidance process for guiding the OCT data to be photographed into the imaging range, and the guidance process for aligning the analysis target with the appropriate position is executed. As a result, it is possible to efficiently advance the imaging of the eye to be inspected and reduce the possibility of re-imaging.

Further, for example, the fundus photography apparatus in this embodiment outputs guide information for guiding the analysis target including at least one of the macula and the papilla to an appropriate position as the guidance process. By using the guide information, the examiner can easily adjust the macula and the nipple to the proper position.

Further, for example, the fundus photography apparatus in the present embodiment superimposes and displays an index indicating a target position for matching the analysis target including at least one of the macula and the papilla to an appropriate position as a guidance process. Let me. The examiner can grasp the deviation between the macula and the nipple and the proper position from such an index, and easily adjust the macula and the nipple to the proper position.

Further, for example, the fundus imaging device in the present embodiment can set a first imaging mode for photographing either the macula or the papilla and a second imaging mode for photographing both the macula and the papilla. Is. For example, in particular, in the second imaging mode, it is necessary to keep both the macula and the papilla within a predetermined imaging range, and these regions are likely to be excluded (or partially missing). Therefore, when the second imaging mode is set, the imaging of the eye to be inspected can be efficiently advanced by aligning the analysis target including at least one of the macula and the nipple with the appropriate position. can.

<Example of transformation>
In this embodiment, the configuration in which the papillary target index 403 for moving the papillary head t is superimposed and displayed on the frontal observation image 400 has been described as an example, but the present invention is not limited to this. In this embodiment, a guide mark for guiding the papilla t to the papilla target index 403 may be superimposed and displayed on the frontal observation image 400 together with the papilla target index 403. In this case, the control unit 300 may display a guide mark for moving the imaging unit 200 based on the deviation between the papilla t and the papilla target index 403. Further, in this case, the control unit 300 moves the fixation lamp position 402 based on the deviation between the papilla t and the papilla target index 403 (in other words, the guide for changing the lighting position of the fixation lamp). The mark M may be superimposed and displayed. Hereinafter, this will be described by taking the movement of the fixation lamp position 402 as an example.

FIG. 6 is an example of the front observation image 400. FIG. 6A shows a state before moving the fixation lamp position 402. FIG. 6A shows a state after moving the fixation lamp position 402. For example, the line of sight of the eye E to be inspected is gazing at the fixation lamp arranged on the measurement optical axis L, and the fixation lamp position 402 is displayed at the center position C of the front observation image 400. The control unit 300 detects the papilla t from the front observation image 400, and calculates the amount and direction of the deviation between the papilla t and the papilla target index 403. Further, the control unit 300 calculates the amount and direction of moving the fixation lamp position 402 based on the deviation between the papilla t and the papilla target index 403. Further, the control unit 300 has a guide mark at the closest position among the fixation lamp positions arranged on the same circumference about the measurement optical axis L based on the amount and direction of moving the fixation lamp position 402. Display M.

The examiner operates the monitor 104 to select the guide mark M superimposed on the front observation image 400 (as an example, a click operation of the guide mark M). The control unit 300 moves the fixation lamp position 402 to the position of the guide mark M. Further, the control unit 300 turns off the fixation lamp on the measurement optical axis L and turns on the corresponding fixation lamp in the vicinity of the measurement optical axis L. For example, when the line-of-sight direction of the eye E to be inspected is changed by this, the papilla t is guided to match the papilla target index 403, and the macula m and the papilla t are kept within the imaging range 401.

The fundus photography apparatus in this embodiment thus detects an analysis target including at least one of the macula and the papilla from the observation image, and based on the detection result, at least the macula and the papilla are used as an induction process. Guide information for guiding the analysis target including any of them to an appropriate position may be output. By using the guide information, the examiner can easily eliminate the deviation between the macula and the nipple and the proper position, and can easily adjust the macula and the nipple to the proper position.

In this embodiment, the configuration in which the examiner manually guides the teat t to the teat target index 403 has been described as an example, but the present invention is not limited to this. In this embodiment, the control unit 300 may automatically guide the teat t to the teat target index 403. In this case, the control unit 300 automatically adjusts the scanning range (shooting range) of the measurement light by the OCT optical system 230 based on the deviation between the papilla t and the papilla target index 403.

For example, the control unit 300 may control the scanning of the optical scanner 234 in order to change the scanning position and scanning direction of the measurement light in the OCT optical system 230. Further, for example, the control unit 300 may control the lighting and extinguishing of the light source in order to change the presentation position of the fixation lamp in the fixation guidance optical system 250. Further, for example, the control unit 300 may control the drive of the drive unit 105 in order to move the imaging unit 200 with respect to the eye E to be examined in at least one of the vertical direction and the horizontal direction. Further, for example, the control unit 300 may control the drive of a drive unit (not shown) in order to tilt (turn) the imaging unit 200 in at least one of the vertical direction and the horizontal direction with respect to the eye E to be inspected. .. The control unit 300 may adjust the imaging range of the measurement light by the OCT optical system 230 by any one of these or a combination thereof, and guide the papilla t to the papilla target index 403.

The fundus photography apparatus in this embodiment guides the macula and the papilla in the observation image into the imaging range of the OCT data by adjusting the imaging range of the OCT data captured by the OCT optical system in this way. You may. For this reason, the deviation between the macula and the nipple and the proper position is automatically eliminated, and the macula and the nipple are appropriately arranged within the imaging range.

In this embodiment, a configuration in which appropriate positions (appropriate positions R1 and R2) are set in advance with respect to the front observation image 400 has been described as an example, but the present invention is not limited thereto. In this embodiment, the macula portion m may be detected from the front observation image 400, and a region separated by a predetermined pixel from the macula portion m may be set as the appropriate position R2 of the papilla t. Further, in this embodiment, the appropriate position R2 of the papilla t may be set by detecting the papillae t from the frontal observation image 400. In this case, the papilla t may be detected based on the brightness of the front observation image 400. Further, in this case, the papilla t may be detected based on the analysis result obtained by analyzing the retinal layer. More specifically, the region where the retinal layer is not detected may be detected as the papilla t. Further, in this embodiment, the axial length of the eye E to be inspected may be acquired, and the position of the papilla t predicted based on the axial length may be set as an appropriate position of the papilla t. In this case, the axial length of the eye to be inspected E may be measured and input using an axial length measuring device or the like.

In this embodiment, the fundus image taken by the observation optical system 240 may be used as the front observation image 400. That is, any of an infrared fundus image by the fundus camera optical system, an SLO front image by the SLO optical system, and the like may be used.

Further, in the present embodiment, the front observation image 400 may be configured to superimpose and display an index indicating the target position for moving the macula portion m. Of course, the index of the target position with respect to the macula m and the papilla target index 403 with respect to the papilla t may be superimposed and displayed.

Further, in the present embodiment, in the macula photographing mode in which the macula portion m of the fundus is photographed, in order to guide the macula portion m within the scanning range (that is, within the imaging range) of the measurement light by the OCT optical system 230, An index indicating the target position of the macula may be superimposed and displayed. Similarly, in the nipple imaging mode in which the nipple t of the fundus is photographed, the nipple target index 403 of the nipple t may be superimposed and displayed in order to guide the nipple t within the scanning range of the measurement light. For example, even in these imaging modes, imaging and analysis can be performed efficiently by guiding the macula m or the papilla t to a target position and matching them with a preset appropriate position.

In this embodiment, the case where the OCT front image (front observation image 400) is selected as the observation image is illustrated, but even when the OCT tomographic image is selected, the papillary target index is similarly superimposed and displayed. It may be a configuration.

FIG. 7 is an example of the OCT tomographic image 500. The imaging range 501, the papilla target index 503, and the like are electrically superimposed and displayed on the OCT tomographic image 500. The position of the fixation lamp presented to the eye E to be inspected (fixation light position) may be displayed separately from the OCT tomographic image 500. Note that FIG. 7A shows a state in which the OCT tomographic image 500 is not tilted, and FIG. 7B shows a state in which the OCT tomographic image 500 is tilted.

The examiner may move or tilt the imaging unit 200 or change the presentation position of the fixation lamp so that the papilla t in the OCT tomographic image 500 matches the papilla target index 503. Alternatively, the control unit 300 may move or tilt the imaging unit 200 or change the presentation position of the fixation lamp so that the papilla t is aligned with the papilla target index 503. Of course, the moving or tilting of the photographing unit 200 and the change of the presentation position of the fixation lamp may be performed together. As a result, the macula m and the nipple t can be placed in the imaging range 501, and the macula m and the nipple t can be arranged at appropriate positions.

For example, in the OCT tomographic image 500, if the retinal layer is tilted and photographed, appropriate analysis results for the macula m and the papilla may not be obtained. Therefore, the OCT tomographic image 500 may display an index 504 indicating the degree of inclination of the retinal layer. For example, the control unit 300 may display the index 504 based on the detection of the retinal layer from the OCT tomographic image 500 and further calculating the inclination of the linear approximation formula (linear approximation formula) of the retinal layer. .. Of course, the calculation of the inclination of the retinal layer is not limited to the method using the linear approximation formula. For example, the inclination of the retinal layer may be calculated based on the brightness distribution of the retinal layer.
The examiner or the control unit 300 adjusts the papilla t to the papilla target index 503, moves or tilts the imaging unit 200 so that the retinal layer is not tilted, or changes the presentation position of the fixation lamp. You may.

The fundus photography apparatus in this embodiment thus acquires an OCT tomographic image as an observation image, and combines at least one of the analysis targets of the macula and the papilla included in the OCT tomographic image with an appropriate position. May be good. For example, by using an OCT tomographic image, it is possible to grasp the inclination of the retinal layer caused by the subject's face being inclined with respect to the imaged part, and to appropriately fit the macula and the nipple within the imaged area. can.

1 Fundus photography device 104 Monitor 200 Imaging unit 230 OCT optical system 300 Control unit 400 Front observation image 403 Papillary target index 500 OCT tomographic image 503 Papillary target index

Claims (8)

It is a fundus photography apparatus that has an OCT optical system that detects an interference signal due to the measurement light and reference light emitted to the fundus of the eye to be inspected, and acquires OCT data of the fundus based on the interference signal. ,
An observation image acquisition means for acquiring an observation image of the fundus,
This is a guidance process for guiding the yellow spot and the papilla included in the observation image into the imaging range of the OCT data imaged by the OCT optical system, and is at least one of the yellow spot and the papilla. A control means for executing guidance processing to match the analysis target including the optical coherence to the appropriate position set within the imaging range in consideration of the area size required for the analysis of the analysis target.
A fundus photography device characterized by being equipped with. In the fundus photography apparatus of claim 1,
The control means is a fundus photography apparatus characterized in that, as the guidance process, guide information for guiding the analysis target to the proper position is output. In the fundus photography apparatus of claim 2,
A detection means for detecting the analysis target from the observation image is provided.
The control means is a fundus photography apparatus characterized in that, based on the detection result of the detection means, the guide information for guiding the analysis target to the proper position is output as the guidance process. In the fundus photography apparatus of claim 2 or 3,
The control means is a fundus photography apparatus, characterized in that, as the guidance process, an index representing a target position for matching the analysis target with the appropriate position is superimposed and displayed on the observation image. In the fundus photography apparatus according to any one of claims 1 to 4,
An adjustment means for adjusting the imaging range of the OCT data imaged by the OCT optical system is provided.
The control means is a fundus photography apparatus characterized by controlling the adjusting means and adjusting the photographing range as the guidance process in order to guide the analysis target into the photographing range. In the fundus photography apparatus according to any one of claims 1 to 5.
The observation image is an OCT tomographic image of the fundus that can be photographed by the OCT optical system. In the fundus photography apparatus according to any one of claims 1 to 6.
A first imaging mode for acquiring the first OCT data in which either the macula or the papilla is photographed, and a second imaging mode in which the second OCT data in which both the macula and the papilla are imaged are acquired. Equipped with a setting means that can be set
The control means is a fundus photography apparatus, characterized in that, when the second photographing mode is set by the setting means, the guidance process for aligning the analysis target with the appropriate position is executed. In the fundus photography apparatus according to any one of claims 1 to 7.
The control means is a fundus photography apparatus characterized by executing the guidance process for aligning the teat with the proper position.

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