Ophthalmologic image processing program and ophthalmologic observation device

Abstract

To provide an ophthalmologic image processing program and ophthalmologic observation device that appropriately display examination data in each of long-term and short-term follow-up observations.SOLUTION: An ophthalmologic observation device executes an image acquisition step of acquiring examination data at different dates and times for the same part of a subject's eye which includes at least an ophthalmologic image, and a display control step of controlling the display of the ophthalmologic image. In the display control step, the display control is switched between a first follow-up observation mode in which the positions of the multiple examination data are corrected on the basis of a baseline and then the multiple examination data are displayed side by side, and a second follow-up observation mode in which one of the multiple examination data is selected as reference examination data, and the position of the comparison examination data is corrected on the basis of the reference examination data regardless of whether the reference examination data is a baseline, and then the reference examination data and the comparison examination data are displayed side by side.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present disclosure relates to an ophthalmic image processing program and an ophthalmic observation device. [Background technology]

[0002] For example, follow-up observation may be performed by taking ophthalmologic images of the same part of a subject on different examination days. For example, in the case of fundus OCT (Optical Coherence Tomography), fundus tomographic images are obtained multiple times, and the progress of the diseased part can be observed from the changes in the tomographic images (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-013341 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventionally, in the case of long-term management of glaucoma, etc., and in the case of management of short-term tissue changes before and after events such as surgery, medication, etc., test data has been displayed based on a baseline. However, as a result of the inventor's investigation, it was found that during follow-up observation, it is not appropriate to always display based on the baseline.

[0005] The present disclosure has been made based on at least some of the problems of the conventional technology, and has as its technical objective to provide an ophthalmic image processing program and an ophthalmic observation device that appropriately display examination data in both long-term and short-term follow-up observations. [Means for solving the problem]

[0006] The ophthalmic image processing program according to the first aspect of the present disclosure is executed by a processor of an ophthalmic observation device, and causes the ophthalmic observation device to execute an image acquisition step of acquiring examination data at different dates and times at the same site of the subject's eye, the examination data including at least an ophthalmic image, and a display control step of controlling the display of the ophthalmic image. In the display control step, a first follow-up observation mode in which a predetermined one of the plurality of examination data is set as a baseline, the positions of the plurality of examination data are corrected based on the baseline, and the plurality of examination data are displayed side by side, and a second follow-up observation mode in which one of the plurality of examination data is selected as reference examination data and at least one more is selected as comparison examination data to be compared with the reference examination data, and regardless of whether the reference examination data is the baseline, the position of the comparison examination data is corrected based on the reference examination data, and the reference examination data and the comparison examination data are displayed side by side.

[0007] An ophthalmic observation device according to a second aspect of the present disclosure executes the ophthalmic image processing program according to the first aspect. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram showing an outline of a device configuration in an embodiment. [Diagram 2] FIG. 2 is a block diagram showing an overview of an optical system in the embodiment. [Diagram 3] 1 is a flowchart showing an outline of an operation flow in an embodiment. [Figure 4] 11 is a flowchart showing a follow-up observation process in the embodiment. [Diagram 5] 13 shows an example of a screen configuration in a first follow-up observation mode. [Figure 6] FIG. 13 is a diagram for explaining positioning in the first follow-up observation mode. [Figure 7] 13 shows an example of a screen configuration in a second follow-up observation mode. [Figure 8] FIG. 13 is a diagram for explaining positioning in the second follow-up observation mode. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [overview] The following embodiments of the present disclosure will be described. Each embodiment may be applied to part or all of the other embodiments. For example, the items grouped in <> below may be used independently or in conjunction with each other.

[0010] The ophthalmic image processing program according to the embodiment is executed by a processor of an ophthalmic observation device to execute each step. In the embodiment, the ophthalmic observation device displays a plurality of pieces of examination data photographed at different dates and times for the same part of the subject's eye side by side for follow-up observation. The ophthalmic observation device may be integrated with the ophthalmic imaging device that performs the photographing, or may be a device separate from the ophthalmic imaging device. If separate, the ophthalmic observation device displays, for example, the examination data photographed by the ophthalmic observation device. For example, a personal computer or the like can be used as the ophthalmic observation device.

[0011] <Image acquisition steps> The ophthalmic observation device acquires examination data, which is examination data on the same part of the subject's eye at different dates and times, including at least an ophthalmic image. The examination data may include an analysis result of the ophthalmic image in addition to the ophthalmic image. In this embodiment, the ophthalmic image included in each examination data is used for alignment between the examination data. The analysis result of the ophthalmic image may be acquired each time based on the ophthalmic image after alignment.

[0012] <Display control steps> The ophthalmologic observation device performs display control of an ophthalmologic image. The ophthalmologic observation device of this embodiment switches the display control between a first follow-up observation mode and a second follow-up observation mode.

[0013] <First follow-up observation mode> In the first follow-up observation mode, a predetermined one of the multiple test data is set as a baseline, and the positions of the multiple test data are corrected based on the baseline, and then the multiple test data are displayed side by side.

[0014] <Second follow-up observation mode> In the second follow-up mode, one of the multiple test data is selected as reference test data, and at least one more is selected as comparison test data to be compared with the reference test data. For example, the reference test data and the comparison test data may be selected at the user's discretion from the multiple test data. In the second follow-up mode, regardless of whether the selected reference test data is a baseline or not, the position of the comparison test data is corrected based on the reference test data, and the reference test data and the comparison test data are displayed side by side.

[0015] In the first follow-up mode, the positions of the multiple test data are corrected based on a predetermined baseline, and the multiple test data are displayed side by side. Unless otherwise specified, the baseline may be the test data captured at the earliest date and time among the multiple test data. In long-term follow-up, changes from the baseline are observed, so the first follow-up mode is suitable for long-term follow-up.

[0016] On the other hand, in short-term follow-up observation, the examination data taken before and after an event such as surgery and medication is compared to observe how much (how) the tissue has changed before and after the event. In the second follow-up observation mode, when the reference examination data and the comparison examination data are selected, the positions of the reference examination data and the comparison examination data are not corrected based on the baseline, but the positions of the comparison examination data are corrected based on the reference examination data, and then the reference examination data and the comparison examination data are displayed side by side. When the baseline is used as the reference, the reference image may also be displaced and displayed according to the baseline, but in this embodiment, the reference image itself is used as the reference, so it is easy to observe how much (how) the tissue has changed before and after the event.

[0017] In this embodiment, the alignment parameters used to correct the position of multiple test data based on a baseline in the first follow-up observation mode may be used to correct the position of comparison test data based on reference test data in the second follow-up observation mode.

[0018] For example, the ophthalmologic observation device may acquire alignment parameters, which are displacements of the plurality of test data from the baseline, using one of the plurality of test data as a baseline. In the second follow-up observation mode, the position of the comparison test data may be corrected based on a first alignment parameter, which is an alignment parameter for the baseline of the reference test data, and a second alignment parameter, which is an alignment parameter for the baseline of the comparison test data.

[0019] In this embodiment, when the position of the comparison inspection data is corrected and displayed based on the reference inspection data, the position of the comparison inspection data can be corrected by reusing the position alignment parameters for the baseline of each inspection data.

[0020] Therefore, when reference test data and comparison test data are selected and displayed, the reference test data and comparison test data can be selected and displayed efficiently from among multiple ophthalmic images without having to determine the alignment parameters for both data by image processing each time, or calculate all patterns of alignment parameters for any two of the multiple ophthalmic images in advance.

[0021] The first follow-up observation mode may be a mode for long-term follow-up observation, and the second follow-up observation mode may be a mode for short-term follow-up observation. For example, the first follow-up observation mode may have a larger number of test data items that can be displayed side by side on the screen than the second follow-up observation mode. Also, each test data item may be displayed larger on the screen than the first follow-up observation mode. This makes it easier to grasp changes over time that occur in a short period of time based on the test data in the second follow-up observation mode.

[0022] The ophthalmologic observation device may further acquire a trend graph showing the change over time of the tissue and the amount of change in the analysis result relative to the baseline as auxiliary information. Since the auxiliary information is useful in long-term follow-up observation, the auxiliary information may be displayed in the first follow-up observation mode out of the first follow-up observation mode and the second follow-up observation mode.

[0023] <Ophthalmological observation device> The fundus photographing device may be an OCT (Optical Coherence Tomography) device. In this case, an OCT image of the fundus is acquired as the fundus image. The OCT image may be a tomographic image (B-scan image), a three-dimensional image, or an enface image. It may also be an intensity OCT image or a motion contrast image. The fundus photographing device may be a front fundus image photographing device. Front fundus image photographing devices are broadly divided into those having a scanning optical system and those having a non-scanning optical system, and either may be used in this embodiment. The fundus photographing device may also be a combined device of an OCT device and a front fundus image photographing device.

[0024] [Example] An embodiment of an ophthalmic image processing device and an ophthalmic image processing program will be described below with reference to the drawings. Note that, in the following, an OCT analysis device 1 will be described as an example of the ophthalmic image processing device. The OCT analysis device 1 shown in FIG. 1 analyzes and processes OCT data acquired by an OCT device 10.

[0025] 1, the OCT analysis device 1 includes, for example, a control unit 70. The control unit 70 is realized by, for example, a general CPU (Central Processing Unit) 71, a ROM 72, a RAM 73, and the like.

[0026] The ROM 72 stores, for example, an ophthalmologic image processing program for processing OCT data, a program for controlling the operation of the OCT device 10 to obtain OCT data, initial values, etc. The RAM 73 temporarily stores, for example, various types of information.

[0027] 1, the control unit 70 is electrically connected to, for example, a storage unit (e.g., non-volatile memory) 74, an operation unit 76, and a display unit 75. The storage unit 74 is, for example, a non-transient storage medium that can retain stored contents even if the power supply is cut off. For example, a hard disk drive, a flash ROM, a removable USB memory, etc. may be used as the storage unit 74.

[0028] In this embodiment, the OCT data acquired by imaging is stored (saved) in the storage unit 74. Therefore, as a result of repeatedly imaging the same subject's eye at different dates and times, a plurality of OCT data pieces repeatedly photographed at different dates and times for the same subject's eye are stored.

[0029] Various operation instructions from the examiner are input to the operation unit 76. The operation unit 76 outputs a signal according to the input operation instruction to the CPU 71. The operation unit 76 may use at least one user interface such as a mouse, a joystick, a keyboard, a touch panel, or the like.

[0030] The display unit 75 may be a display mounted on the main body of the apparatus 1 or a display connected to the main body. For example, a display of a personal computer (hereinafter, referred to as "PC") may be used. The display unit 75 displays, for example, OCT data acquired by the OCT device 10 and results of analysis processing on the OCT data.

[0031] Note that, for example, an OCT device 10 is connected to the OCT analysis apparatus 1 of the present embodiment. Note that the OCT analysis apparatus 1 may have an integrated configuration housed in the same housing as the OCT device 10, for example, or may have a separate configuration. The control unit 70 may acquire OCT data from the connected OCT device 10. The control unit 70 may acquire the OCT data acquired by the OCT device 10 via a storage medium.

[0032] <OCT device> Hereinafter, the outline of the OCT device 10 will be described with reference to FIG. 2. For example, the OCT device 10 irradiates the eye to be examined E with measurement light and acquires a spectral interference signal between the reflected light and the reference light. By performing predetermined processing on the spectral interference signal, OCT data is generated and acquired. The OCT device 10 mainly includes, for example, an OCT optical system 100.

[0033] <OCT optical system> The OCT optical system 100 irradiates the eye to be examined E with measurement light and detects a spectral interference signal between the reflected light and the reference light. The OCT optical system 100 mainly includes, for example, a measurement light source 102, a coupler (optical splitter) 104, a measurement optical system 106, a reference optical system 110, a detector 120, and the like. For details of the configuration of the OCT optical system, refer to, for example, Japanese Patent Application Laid-Open No. 2015-131107.

[0034] The OCT optical system 100 is an optical system of a so-called optical coherence tomography (OCT). The OCT optical system 100 divides the light emitted from the measurement light source 102 into measurement light (sample light) and reference light by the coupler 104. The divided measurement light is guided to the measurement optical system 106, and the reference light is guided to the reference optical system 110, respectively. The measurement light is guided to the fundus Ef of the eye to be examined E through the measurement optical system 106. Thereafter, the detector 120 receives the interference light formed by the combination of the measurement light reflected by the eye to be examined E and the reference light.

[0035] The measurement optical system 106 includes, for example, a scanning unit (for example, an optical scanner) 108. The scanning unit 108 may be provided to scan the measurement light in the XY directions (transverse directions) on the fundus. The scanning unit 108 may be used to change the imaging range of the OCT data. For example, the CPU 71 controls the operation of the scanning unit 108 based on the set scanning position information, and acquires OCT data of the fundus based on the spectral interference signal detected by the detector 120. The reference optical system 110 generates a reference light to be combined with the reflected light acquired by reflection of the measurement light on the fundus Ef. The reference optical system 110 may be a Michelson type or a Mach-Zehnder type.

[0036] The detector 120 detects the interference state between the measurement light and the reference light. In the case of Fourier domain OCT, the detector 120 detects the spectral intensity of the interference light, and a depth profile (A-scan signal) in a predetermined range is acquired by Fourier transforming the spectral intensity data. Scanning the measurement light along one scan line on the fundus Ef is called a "B-scan." Two-dimensional OCT data of the fundus is obtained by one B-scan. Three-dimensional OCT data of the fundus is obtained based on scanning the measurement light along multiple scan lines. The three-dimensional OCT data may be acquired based on, for example, a raster scan.

[0037] As the OCT device 10, for example, a Spectral-domain OCT (SD-OCT), a Swept-source OCT (SS-OCT), a Time-domain OCT (TD-OCT), or the like may be used.

[0038] <Frontal shooting optical system> The front photographing optical system 200 photographs the fundus Ef of the subject's eye E from the front direction (for example, the optical axis direction of the measurement light) to obtain a front image of the fundus Ef. The front photographing optical system 200 may be, for example, a scanning laser ophthalmoscope (SLO) device configuration (for example, see JP 2015-66242 A), or may be a so-called fundus camera type configuration (see JP 2011-10944 A). The front photographing optical system 200 may also be used by the OCT optical system 100, and the front image may be obtained based on a detection signal from the detector 120.

[0039] <Fixation target projection unit> The fixation target projection unit 300 has an optical system for guiding the gaze direction of the eye E. The projection unit 300 has a fixation target to be presented to the eye E, and can guide the eye E. For example, the fixation target projection unit 300 has a visible light source that emits visible light, and changes the presentation position of the fixation target two-dimensionally. This changes the gaze direction, and as a result, the location where OCT data is acquired is changed on the fundus.

[0040] <Operation description> In order to perform follow-up observation in the OCT analysis device 1 of this embodiment, processing is performed in the order of the flowchart shown in FIG. 3. First, a plurality of OCT data photographed at different dates and times for the same part of the subject's eye and analysis results for each of the plurality of OCT data are acquired by the OCT analysis device 1 (S1). In this embodiment, the examination data includes the OCT data and the analysis results thereof. As an example, the OCT data in this embodiment is three-dimensional OCT data (volume data) obtained by map scanning a predetermined two-dimensional range on the fundus. Any of the acquired plurality of OCT data is registered as a baseline for follow-up observation (S2). Usually, the OCT data on the earliest photographing date is registered as the baseline. Next, between the OCT data of the same part, alignment parameters that are the amount of displacement relative to the baseline are acquired (S3). In this embodiment, at least the amount of displacement in the transverse direction (XY direction) is acquired as the alignment parameter. The amount of displacement may include, for example, at least translation and rotation, and may additionally include enlargement / reduction and skew. For example, a transformation matrix (hereinafter, may be referred to as a transformation matrix M) from a fundus front image corresponding to the baseline and a fundus front image corresponding to each 3D OCT data to the baseline may be acquired as a positioning parameter. In this embodiment, as an example, an en-face image based on the 3D OCT data is used to acquire the positioning parameter. However, a fundus image captured by a front photographing optical system at substantially the same time as the 3D OCT data may be used for positioning. The acquired OCT data and the positioning parameters are stored in the storage unit 74. A follow-up observation process (S4) is performed in a state where a plurality of OCT data captured at different dates and times for the same part of the subject's eye and positioning parameters based on the baseline are acquired. The follow-up observation process will be described in detail below.

[0041] Next, the follow-up observation process performed by the OCT analysis device 1 will be described with reference to FIGS.

[0042] FIG. 4 is a flowchart illustrating the flow of the follow-up observation process.

[0043] In the follow-up process, first, one of two follow-up modes, a first follow-up mode and a second follow-up mode, is selected based on a selection operation (S11). Here, the first follow-up mode is a mode intended for long-term follow-up, and the second follow-up mode is a mode intended for short-term follow-up.

[0044] <First follow-up observation mode> An example of a screen configuration in the first follow-up observation mode of this embodiment is shown in Fig. 5. As shown in Fig. 5, in the first follow-up observation mode, examination data 540a to 540d are arranged in chronological order from left to right.

[0045] Examination data 540a is baseline data, and examination data 540b to 540d were taken on a date after the baseline. A date selection list 520 is arranged on the screen, and up to three dates, excluding the baseline, can be selected from the multiple OCT data on list 520. The OCT data taken on the selected dates are displayed as examination data 540b to 540d. In list 520, check marks are displayed next to the baseline date and the selected date to indicate that they have been selected.

[0046] In FIG. 5, as the examination data 540a to 540d, OCT en-face images based on fundus volume data, and analysis maps and analysis charts acquired by analyzing the fundus volume data are displayed.

[0047] The analysis map is a color map showing a two-dimensional distribution of retinal thickness, and is color-coded according to layer thickness. In this embodiment, the analysis map is superimposed on the en-face image. The analysis map may show a two-dimensional distribution of measurement values ​​(actual measurements) based on three-dimensional OCT data, or may show a comparison result between the measurement values ​​and normal eye data. The normal eye data may be statistical data of a normal eye regarding the measurement values ​​based on the three-dimensional OCT data. The comparison result may be information showing the degree of deviation between the measurement values ​​(actual measurements) and the normal eye data, and may be expressed, for example, by any of a difference, a ratio (e.g., percentile), and a standard deviation. The analysis map may also show a two-dimensional distribution of the change over time in the measurement values ​​or the above comparison result.

[0048] As an analytical chart showing the thickness of a tissue, a GCHART, an S / I chart, an ETDS chart, etc. may be used.

[0049] In the first follow-up mode, the position of each piece of OCT data (here, the en-face image, the analysis map, and the analysis chart) is corrected with reference to the baseline test data 540a. That is, with reference to the baseline test data 540a, the display positions of the other test data 540b to 540d or the positions of the analysis ranges are corrected. As shown in FIG. 6, the position correction is performed by applying the corresponding alignment parameters (the transformation matrix M to the baseline) to each piece of OCT data.

[0050] As shown in Fig. 5, in the first follow-up observation mode, a trend graph 550 is displayed on the screen. In the trend graph 550, analysis results (information on layer thickness) corresponding to the OCT data on each imaging date are plotted along the time axis. In this embodiment, multiple trend graphs are created for each analysis position and layer region and displayed side by side.

[0051] <Second follow-up observation mode> An example of a screen configuration in the second follow-up observation mode of this embodiment is shown in Fig. 7. As shown in Fig. 7, in the second follow-up observation mode, two OCT data, that is, reference test data 530a and comparison test data 530b, are displayed side by side.

[0052] FIG. 7 shows reference test data 530a and comparative test data 530b, which include a cross-sectional image (B-scan image) of the fundus, a frontal image of the fundus taken simultaneously with the volume data of the fundus, an analysis map obtained by analyzing the volume data of the fundus, and a structural abnormality map. The analysis map and the structural abnormality map are superimposed on the frontal image of the fundus. The structural abnormality map is a type of map of the analysis result. A probability distribution for identifying two or more tissues is obtained by a segmentation process using a machine learning model, and a two-dimensional distribution of the probability distribution is obtained, thereby generating a structural abnormality map. For details, please refer to, for example, "JP Patent Publication No. 2022-82077" by the present applicant.

[0053] The reference examination data 530a is OCT data captured on a desired date among the dates selectable in the date selection list 520. The reference examination data 530a can be selected regardless of whether it is registered in the baseline. The comparison examination data 530b is OCT data to be compared with the reference examination data 530a. OCT data captured on dates before or after an event such as surgery or medication may be selected as the reference examination data 530a and the comparison examination data 530b.

[0054] In the date selection list 520, a blue check mark 521a is added to the photographing date of the reference examination data 530a, and a green check mark 521b is added to the photographing date of the comparison examination data 530b. When changing the comparison examination data 530b to one of a different date, a green check mark 521b is added to the selected date by simply selecting the new date, and the display is switched to the comparison examination data 530b corresponding to the newly selected date. On the other hand, when changing the reference examination data 530a, a more complicated operation procedure is required. For example, a predetermined release operation may be performed, and then a selection operation may be performed for a new date. This makes it possible to efficiently compare with the OCT data of the desired photographing date while suppressing operational errors regarding image selection in short-term follow-up observation.

[0055] In the second follow-up observation mode, the comparative test data 530b is displayed with its position corrected based on the reference test data 530a. That is, as shown in FIG. 8, a transformation based on the alignment parameters of the comparative test data 530b (a transformation matrix M from the comparative test data 530b to the baseline) and an inverse transformation based on the alignment parameters of the reference test data 530a (an inverse transformation matrix M from the reference test data 530a to the baseline) are performed. -1 ) is applied to the comparison inspection data 530b. Therefore, the position of the comparison inspection data 530b is corrected with respect to the reference inspection data 530a by using the prepared alignment parameters.

[0056] Therefore, in this embodiment, the positions of the B-scan image, frontal fundus image, analysis map, and structural abnormality map in the reference test data 530a and the comparison test data 530b shown in Figure 7 are determined and displayed based on the position of an en-face image (not shown) based on the volume data contained in the reference test data 530a.

[0057] In this manner, in this embodiment, even if the reference inspection data 530a and the comparison inspection data 530b are selected in any combination, the position of the comparison inspection data 530b is appropriately corrected based on the position of the reference inspection data 530a without the need to obtain the alignment parameters for both of them by image processing each time, or to calculate in advance the alignment parameters for any two data out of the multiple OCT data corresponding to each shooting date for all patterns. [Explanation of symbols]

[0058] 1 OCT analysis device 10. OCT Device 71 CPU

Claims

1. When executed by a processor of the ophthalmic observation device, an image acquiring step of acquiring examination data at different dates and times for the same part of the subject's eye, the examination data including at least an ophthalmologic image; a display control step of controlling the display of the ophthalmologic image by the ophthalmologic observation device; In the display control step, a first follow-up observation mode in which a predetermined one of the plurality of test data is set as a baseline, positions of the plurality of test data are corrected based on the baseline, and the plurality of test data are displayed side by side; a second follow-up observation mode in which one of the plurality of test data is selected as reference test data and at least one more is selected as comparison test data to be compared with the reference test data, and the reference test data and the comparison test data are displayed side by side after correcting the position of the comparison test data based on the reference test data, regardless of whether the reference test data is the baseline or not; An ophthalmology image processing program that switches display control between.

2. 2. The ophthalmologic image processing program according to claim 1, a registration parameter acquisition step of acquiring registration parameters, which are amounts of displacement of each of the plurality of pieces of inspection data from a baseline, using any of the plurality of pieces of inspection data as a baseline; In the display control step, The position of the comparison inspection data is corrected based on a first alignment parameter which is the alignment parameter relative to the baseline in the reference inspection data, and a second alignment parameter which is the alignment parameter relative to the baseline in the comparison inspection data.

3. 3. The ophthalmologic image processing program according to claim 1, an auxiliary information acquiring step of acquiring, as auxiliary information, a trend graph showing a change in tissue over time and an amount of change in the analysis result relative to the baseline as an analysis result of the plurality of test data; In the first follow-up observation mode, at least one of a trend graph relating to an analysis result corresponding to the plurality of test data and difference information of the analysis result from a baseline is displayed as auxiliary information together with the plurality of test data, and In the second follow-up mode, the auxiliary information is not displayed.

4. 4. The ophthalmologic image processing program according to claim 1, The examination data includes OCT data.

5. An ophthalmologic observation device that executes the ophthalmologic image processing program according to any one of claims 1 to 4.

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