JP2016093510A - Ocular fundus laser photocoagulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To acquire information useful for laser treatment of a patient's eye.SOLUTION: An ocular fundus laser photocoagulator includes: an irradiation optical system having a treatment laser source and deflection means for deflecting a laser beam emitted from the treatment laser source to the oculus fundus Ef of a patient's eye; irradiation position acquisition means for acquiring irradiation position information on a treatment laser beam for the oculus fundus of the patient's eye based on an OCT image of the oculus fundus of the patient's eye taken by an optical coherence tomographic device before the laser beam is irradiated; and laser control means for irradiating the laser beam to the oculus fundus of the patient's eye based on the irradiation position information acquired by the irradiation position acquisition means by controlling operations of the laser source and the deflection means. The optical coherence tomographic device is arranged as a housing different from the ocular fundus laser photocoagulator 400.SELECTED DRAWING: Figure 1

Description

The present invention relates to a fundus photocoagulation laser device used when irradiating a patient's eye with laser light.

  2. Description of the Related Art A therapeutic laser device that performs treatment of an eye by irradiating a treatment laser beam onto a tissue (for example, a fundus) of a patient's eye is known (see Patent Document 1). When such an apparatus is used, the operator observes the fundus front image using a slit lamp and a fundus camera, and irradiates the treatment site of the eye with laser light.

JP 2010-148635 A

  However, in the case of the front observation optical system, it is difficult to obtain only surface information of the patient's eyes. For example, in the front observation image, it is difficult to confirm the state of the photoreceptor cell, and in the case of diabetic retinopathy, laser irradiation is performed regardless of whether the photoreceptor cell is normal or not.

In view of the above problems, an object of the present invention is to provide a fundus photocoagulation laser device that can acquire information useful for laser treatment of a patient's eye.

  In order to solve the above problems, the present invention has the following configuration.

(1)
A treatment laser light source; and deflection means for deflecting laser light emitted from the treatment laser light source with respect to the fundus of the patient's eye, and an irradiation optical system for irradiating the treatment site on the patient's eye fundus;
Irradiation position acquisition means for acquiring irradiation position information of a therapeutic laser on the patient's eye fundus based on an OCT image of the patient's eye fundus captured by an optical coherence tomography device before the laser light is irradiated;
Laser control means for irradiating the patient's eye fundus with laser light based on the irradiation position information acquired by the irradiation position acquisition means by controlling the operations of the laser light source and the deflection means;
With
The optical coherence tomography device is arranged as a housing different from the fundus photocoagulation laser apparatus.

  According to the present invention, information useful for laser treatment of a patient's eye can be acquired.

  Embodiments according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram illustrating the configuration of the ophthalmologic photographing apparatus according to the present embodiment. In the present embodiment, the axial direction of the subject's eye (eye E) will be described as the Z direction, the horizontal direction as the X direction, and the vertical direction as the Y direction. The surface direction of the fundus may be considered as the XY direction.

  An outline of the apparatus configuration will be described. This apparatus is an optical coherence tomography device (OCT device) 10 for taking a tomographic image of the fundus oculi Ef of the subject's eye E. The OCT device 10 includes an interference optical system (OCT optical system) 100, a front observation optical system 200, a fixation target projection unit 300, a photocoagulation laser device 400, and an arithmetic control unit (CPU) 70.

  The OCT optical system 100 irradiates the fundus with measurement light. The OCT optical system 100 detects the interference state between the measurement light reflected from the fundus and the reference light by the light receiving element (detector 120). The OCT optical system 100 includes an irradiation position changing unit (for example, the optical scanner 108 and the fixation target projection unit 300) that changes the irradiation position of the measurement light on the fundus oculi Ef in order to change the imaging position on the fundus oculi Ef. The control unit 70 controls the operation of the irradiation position changing unit based on the set imaging position information, and acquires a tomographic image based on the light reception signal from the detector 120. The photocoagulation laser device 400 oscillates a therapeutic laser (photocoagulation laser beam).

<OCT optical system>
The OCT optical system 100 has a so-called ophthalmic optical tomography (OCT: Optical coherence tomography) apparatus configuration. In this embodiment, the OCT optical system 100 captures a tomographic image of a patient's eye before irradiation with a therapeutic laser. The OCT optical system 100 splits the light emitted from the measurement light source 102 into measurement light (sample light) and reference light by a coupler (light splitter) 104. The OCT optical system 100 guides the measurement light to the fundus oculi Ef of the eye E by the measurement optical system 106 and guides the reference light to the reference optical system 110. Thereafter, the detector (light receiving element) 120 receives the interference light obtained by combining the measurement light reflected by the fundus oculi Ef and the reference light.

  The detector 120 detects an interference state between the measurement light and the reference light. In the case of Fourier domain OCT, the spectral intensity of the interference light is detected by the detector 120, and a depth profile (A scan signal) in a predetermined range is obtained by Fourier transform on the spectral intensity data. Examples include Spectral-domain OCT (SD-OCT) and Swept-source OCT (SS-OCT). Moreover, Time-domain OCT (TD-OCT) may be used.

  In the case of SD-OCT, a low-coherent light source (broadband light source) is used as the light source 102, and the detector 120 is provided with a spectroscopic optical system (spectrum meter) that separates interference light into each frequency component (each wavelength component). . The spectrum meter includes, for example, a diffraction grating and a line sensor.

  In the case of SS-OCT, a wavelength scanning light source (wavelength variable light source) that changes the emission wavelength at a high speed in time is used as the light source 102, and a single light receiving element is provided as the detector 120, for example. The light source 102 includes, for example, a light source, a fiber ring resonator, and a wavelength selection filter. Examples of the wavelength selection filter include a combination of a diffraction grating and a polygon mirror, and a filter using a Fabry-Perot etalon.

  The light emitted from the light source 102 is split into a measurement light beam and a reference light beam by the coupler 104. Then, the measurement light flux passes through the optical fiber and is then emitted into the air. The luminous flux is condensed on the fundus oculi Ef via the optical scanner 108 and other optical members of the measurement optical system 106. Then, the light reflected by the fundus oculi Ef is returned to the optical fiber through a similar optical path.

  The optical scanner 108 scans the measurement light in the XY direction (transverse direction) on the fundus. The optical scanner 108 is arranged at a position substantially conjugate with the pupil. The optical scanner 108 is, for example, two galvanometer mirrors, and the reflection angle thereof is arbitrarily adjusted by the drive mechanism 50.

  Thereby, the reflection (advance) direction of the light beam emitted from the light source 102 is changed, and is scanned in an arbitrary direction on the fundus. Thereby, the imaging position on the fundus oculi Ef is changed. The optical scanner 108 may be configured to deflect light. For example, in addition to a reflective mirror (galvano mirror, polygon mirror, resonant scanner), an acousto-optic device (AOM) that changes the traveling (deflection) direction of light is used.

  The reference optical system 110 generates reference light that is combined with reflected light acquired by reflection of measurement light at the fundus oculi Ef. The reference optical system 110 may be a Michelson type or a Mach-Zehnder type. The reference optical system 110 is formed by, for example, a reflection optical system (for example, a reference mirror), and reflects light from the coupler 104 back to the coupler 104 by being reflected by the reflection optical system and guides it to the detector 120. As another example, the reference optical system 110 is formed by a transmission optical system (for example, an optical fiber), and guides the light from the coupler 104 to the detector 120 by transmitting the light without returning.

  The reference optical system 110 has a configuration in which the optical path length difference between the measurement light and the reference light is changed by moving an optical member in the reference optical path. For example, the reference mirror is moved in the optical axis direction. The configuration for changing the optical path length difference may be arranged in the measurement optical path of the measurement optical system 106.

<Front observation optical system>
The front observation optical system 200 is provided to obtain a front image of the fundus oculi Ef. The observation optical system 200 includes, for example, an optical scanner that two-dimensionally scans the fundus of measurement light (for example, infrared light) emitted from a light source, and a confocal aperture that is disposed at a position substantially conjugate with the fundus. And a second light receiving element for receiving the fundus reflection light, and has a so-called ophthalmic scanning laser ophthalmoscope (SLO) device configuration.

  Note that the configuration of the observation optical system 200 may be a so-called fundus camera type configuration. The OCT optical system 100 may also serve as the observation optical system 200. That is, the front image may be acquired using data forming a tomographic image obtained two-dimensionally (for example, an integrated image in the depth direction of the three-dimensional tomographic image, at each XY position). The integrated value of the spectrum data.

<Fixation target projection unit>
The fixation target projecting unit 300 includes an optical system for guiding the line-of-sight direction of the eye E. The projection unit 300 has a fixation target presented to the eye E, and can guide the eye E in a plurality of directions.

  For example, the fixation target projection unit 300 has a visible light source that emits visible light, and changes the presentation position of the target two-dimensionally. Thereby, the line-of-sight direction is changed, and as a result, the imaging region is changed. For example, when the fixation target is presented from the same direction as the imaging optical axis, the center of the fundus is set as the imaging site. When the fixation target is presented upward with respect to the imaging optical axis, the upper part of the fundus is set as the imaging region. That is, the imaging region is changed according to the position of the target with respect to the imaging optical axis.

  As the fixation target projection unit 300, for example, a configuration in which the fixation position is adjusted by the lighting positions of LEDs arranged in a matrix, light from a light source is scanned using an optical scanner, and fixation is performed by lighting control of the light source. Various configurations such as a configuration for adjusting the position are conceivable. The projection unit 300 may be an internal fixation lamp type or an external fixation lamp type.

<Photocoagulation laser device>
The photocoagulation laser device 400 has a laser light source and oscillates a therapeutic laser beam (for example, a wavelength of 532 nm). The light emitted from the light source of the photocoagulation laser apparatus 400 is introduced into the optical fiber 401 and emitted from the emission end 401a. The laser light emitted from the emission end 401 a is reflected by the dichroic mirror 30 and is condensed on the fundus oculi Ef via the optical scanner 108 and other optical members of the measurement optical system 106. The optical scanner 108 deflects the laser light emitted from the laser light source to the eye E as an optical deflecting unit. In this case, the measurement optical system 106 is used as an irradiation optical system that irradiates the treatment site of the eye with laser light.

  As a result, the reflection (advance) direction of the laser light emitted from the photocoagulation laser apparatus 400 is changed by the optical scanner 108 and scanned two-dimensionally on the fundus. Thereby, the irradiation position of the laser beam on the fundus oculi Ef is changed.

  The photocoagulation laser device 400 may be configured to include an aiming light source that emits aiming light in addition to the therapeutic laser light source.

<Control unit>
The control unit 70 controls the entire apparatus such as each member of each configuration 100 to 400. The control unit 70 also serves as an image processing unit that processes the acquired image, an image analysis unit that analyzes the acquired image, and the like. The control unit 70 is realized by a general CPU (Central Processing Unit) or the like.

  2A is an example of a front image obtained by the front observation optical system 200, and FIG. 2B is an example of a tomographic image obtained by the OCT optical system 100. FIG. For example, the control unit 70 acquires a tomographic image (OCT image) by image processing based on the light reception signal output from the detector 120 of the OCT optical system 100 and outputs it from the light receiving element of the front observation optical system 200. A front image is acquired based on the received light signal. Further, the control unit 70 controls the fixation target projection unit 300 to change the fixation position.

  The memory (storage unit) 72, the monitor (display unit) 75, and the operation unit 76 are electrically connected to the control unit 70, respectively. The control unit 70 controls the display screen of the monitor 75. The acquired fundus image is output to the monitor 75 as a still image or a moving image and stored in the memory 72. The memory 72 records, for example, various types of information related to imaging such as the captured tomographic image, the front image, and the imaging position information of each tomographic image. The control unit 70 controls each member of the OCT optical system 100, the front observation optical system 200, and the fixation target projection unit 300 based on the operation signal output from the operation unit 76. Further, a touch panel is used as the monitor 75. For the detailed configuration of the OCT device 10, refer to, for example, Japanese Patent Application Laid-Open No. 2008-29467.

  In this example, an eye to be examined with diabetic retinopathy is taken as an example. Hereinafter, a procedure for treating diabetic retinopathy with a laser beam will be described.

  <Acquisition of Tomographic Image> The control unit 70 controls the OCT optical system 100 to acquire a three-dimensional tomographic image corresponding to each set region, and also controls the observation optical system 200 to acquire a front image. The three-dimensional tomographic image includes image data in which A scan signals are arranged two-dimensionally in the XY directions, a three-dimensional graphic image, and the like.

  When obtaining a three-dimensional tomographic image, the control unit 70 controls the operation of the optical scanner 108 and acquires the three-dimensional tomographic image by scanning the measurement light in the XY directions two-dimensionally in the scanning range corresponding to the imaging region. To do. As the scanning pattern, for example, a raster scan and a plurality of line scans can be considered.

<Determination of photoreceptor cells>
The control unit 70 has an image analysis unit. When the tomographic image is acquired, the control unit 70 detects fundus layer information in the acquired tomographic image by image processing. Then, the OCT device 100 analyzes the layer detection result based on a predetermined image determination condition (determination criterion). As an example of analysis, the control unit 70 detects layer information at each position in the XY directions, and analyzes the state of the photoreceptor cell at each position based on the detected layer information. The analysis result is stored together with the three-dimensional tomogram in the memory of the OCT device 100 or in an external memory (for example, a memory of a personal computer or a memory of a server).

  When detecting a layer, for example, the luminance level of a tomographic image is detected, and a layer corresponding to a predetermined retinal layer (for example, a photoreceptor inner / outer segment (hereinafter referred to as IS / OS)) is extracted by image processing. Is done.

  When determining a tomographic image, the determination of the presence or absence of each layer, the determination of the layer thickness of each layer, the shape determination, the size determination of a predetermined part (for example, a nipple, a macula), etc. can be considered. For example, the control unit 70 detects the luminance distribution of each A scan signal, and determines the presence / absence of IS / OS according to whether or not an increase in luminance corresponding to IS / OS is detected.

  FIG. 3A shows an example of a luminance distribution in a state where IS / OS remains, and FIG. 3B shows an example of a luminance distribution in a state where IS / OS disappears. That is, when IS / OS remains, a peak corresponding to IS / OS is seen, but when IS / OS disappears, there is no peak corresponding to IS / OS and a peak corresponding to RPE. appear. When specifying the presence / absence of IS / OS, the anatomically known order of each layer, the distance from the retina surface, the rise of strong luminance corresponding to IS / OS, and the like are used.

  The control unit 70 analyzes a tomographic image of the fundus and performs a determination process regarding the normal / abnormal part of the visual function, and acquires position information on the normal / abnormal part of the visual function on the patient's eye fundus as analysis result data.

  The control unit 70 regards the position where it is determined that the IS / OS remains as a part where the photoreceptor cell is highly likely to function normally. Next, the control unit 70 regards the position where it is determined that the IS / OS has disappeared as a site where the function of the photoreceptor cell is highly likely to be degraded.

  As described above, the control unit 70 obtains two-dimensional information on the fundus regarding the presence / absence of IS / OS by making a determination regarding the presence / absence of IS / OS for each A scan signal. Thereby, the site | part with a reduced function of the photoreceptor cell on a fundus is specified.

  FIG. 4 is a diagram showing the analysis result of the tomographic image, and is an example of a map (hereinafter referred to as an analysis map) that two-dimensionally shows the state of the visual function at each position on the fundus. In the present embodiment, the control unit 70 acquires an analysis map indicating two-dimensional distribution data regarding normal / abnormal parts of the visual function as analysis result data. That is, based on the analysis result acquired as described above, an analysis map indicating the analysis result of the three-dimensional tomographic image is created. As shown in FIG. 4, the control unit 70 displays a graphic (see hatching R) that indicates a part where the visual function is deteriorated. For example, the hatching R is displayed in a specific color (for example, red). In addition, the control unit 70 may surround a region where the visual function is deteriorated with a marker. Of course, the control unit 70 may display an identifiable graphic regarding a site where the photoreceptor cell functions normally.

  In addition, when obtaining an analysis result, in addition to the analysis by image processing, a configuration in which the examiner himself specifies a site where the visual function is deteriorated may be used. In this case, for example, in a state where the tomographic image is displayed on the monitor 75, a region where the visual function is deteriorated is designated by a mouse operation. Then, an analysis map is created based on the designated result. The obtained analysis map is stored in the memory 72.

<Setting of laser irradiation position>
Next, the control unit 70 acquires analysis result data based on a tomographic image of the patient's eye imaged by the OCT device 10 before the treatment laser is irradiated. And the control part 70 acquires the irradiation position information of the treatment laser with respect to the eye E set using the acquired analysis result data. Typically, the control unit 70 causes the monitor 75 to display the front image acquired by the observation optical system 200 and the analysis result data in a superimposed manner.

  When acquiring the analysis result data based on the tomographic image, the control unit 70 may acquire the analysis result data by performing the analysis processing as described above by the control unit 70 itself, or in advance to another analysis device. You may acquire the data analyzed by.

  The touch panel of the monitor 75 is used as an operation member for an operator to set a treatment laser irradiation area while viewing the screen of the monitor 75. And the control part 70 acquires the irradiation position information of the treatment laser with respect to the eye E based on the operation signal from a touch panel. The operation member is not limited to the touch panel, and for example, a pointing device such as a mouse or a joystick is used.

  For example, the control unit 70 acquires an analysis map stored in the memory 72. Then, the control unit 70 superimposes the fundus front image on the analysis map acquired as described above, and associates the analysis map with the fundus front image. The control unit 70 displays a superimposed image of the analysis map and the fundus front image on the monitor 75.

  The control unit 70 generates an OCT front image from the three-dimensional tomographic image used for the analysis, and associates both data in a pixel-to-pixel relationship by superimposing the generated OCT front image and the analysis map. it can. Further, the control unit 70 may superimpose a fundus front image (for example, an SLO image) acquired by the observation optical system 200 and an analysis map. Note that the acquisition timing of the superimposed SLO image may be at the time of acquisition of a three-dimensional tomographic image, or may be before actual laser irradiation through various inspections. The acquired front image is stored in the memory 72 as a still image.

  For example, the control unit 70 matches the generated OCT front image and the fundus front image acquired by the observation optical system 200, and adjusts the relative position between the analysis map M and the fundus front image. That is, the analysis map is superimposed on the still image of the front image by image processing, and the superimposed image is displayed on the monitor 75. At this time, for example, the control unit 70 displays the position where the visual function is determined to be abnormal as a laser irradiation region based on the position information regarding the normal / abnormal part of the visual function, and the visual function is determined to be normal. The position is displayed as a laser irradiation prohibited area. FIG. 5A is a diagram showing an example in which the analysis map M and the irradiation prohibited area D are displayed on the fundus front image on the monitor 75.

  The examiner sets the laser irradiation region while viewing the superimposed image displayed on the monitor 75. First, the examiner searches for a treatment site while observing the fundus front image displayed on the monitor 75 and sets a laser irradiation region. At this time, the examiner sets the laser irradiation region by using a touch panel (operation unit) on the monitor. When receiving a signal from the touch panel, the control unit 70 further displays a graphic G indicating the laser irradiation area on the superimposed image and sets the designated position as the irradiation area (see FIG. 5B). As a setting method on the screen, for example, a method in which the vicinity of the touched region is set as the irradiation region, or a method in which the region surrounded by the tracing operation is set as the irradiation region can be considered. Of course, the examiner may set a region not to be irradiated (irradiation prohibited region) and irradiate the region excluding the irradiation prohibited region with a laser.

  At this time, the control unit 70 sets a portion where the photoreceptor cells function normally on the analysis map as the irradiation prohibited region D, and displays a graphic indicating the irradiation prohibited region D in a superimposed manner (see FIG. 5B). ). In this case, even if the laser irradiation region G is set so as to include the irradiation prohibited region D, the control unit 70 excludes the irradiation prohibited region D from the laser irradiation region G. In addition, when there are many regions where the photoreceptor cells are normal, laser irradiation is limited, and there is a possibility that the treatment is insufficient, so the control unit 70 may arbitrarily release the irradiation prohibited region D. In addition, since the examiner can grasp the state of the visual function of the eye E using an analysis map or the like, it is possible to arbitrarily exclude a portion where the photoreceptor cells are normal from the irradiation prohibited region.

  The control unit 70 may specify a predetermined part (for example, macular, nipple) of the fundus in the three-dimensional tomographic image by image processing, and set the specified part as the irradiation prohibited area D. For example, the macula and nipple can be extracted from the position, luminance value, shape, etc. in the tomographic image. Since the macular part has a darker brightness than the peripheral part and has a circular shape, image processing is performed so that an image region that matches these characteristics is extracted. Since the nipple is brighter than the periphery and has a circular shape, image processing is performed so that an image region that matches these characteristics is extracted. Note that the control unit 70 may specify the macular portion and the nipple by image processing using a fundus front image (for example, an SLO image), and set the specified portion as the irradiation prohibited region D.

  In the present embodiment, the control unit 70 detects the position of the macular portion and the nipple and sets it as the irradiation prohibited region. However, when the examiner observes the fundus image displayed on the monitor 75, the macular portion Alternatively, the position of the nipple may be selected and set as the irradiation prohibited area.

  At this time, the control unit 70 displays an analysis map on the front image of the fundus and sets an irradiation prohibited region from the position of the macula and the nipple. Then, an irradiation prohibited area image for indicating the irradiation prohibited area is created and displayed on the fundus front image. In addition, detection of a macular part and a nipple is detected based on the data acquired when the OCT front image and the SLO image were analyzed, for example.

  When the analysis map M and the fundus front image are associated with each other, analysis information is given to each pixel of the fundus front image. Here, the correspondence between the position coordinates on the fundus front image and the scanning position of the optical scanner 108 is determined in advance. Therefore, it is possible to associate the scanning position of the optical scanner 108 with the position coordinates of the analysis map. Thereby, the scanning position (scanning angle) of the laser beam scanned by the optical scanner 108 is associated with the analysis information on the analysis map. For example, the portion where the visual function is lowered is associated with the irradiation position of the laser beam.

<Laser irradiation>
Next, the control unit 70 controls the operation of the laser light source and the optical scanner 108 to irradiate the eye with laser light based on the irradiation position information acquired as described above.

  For example, when the laser irradiation region and the prohibited region are set as described above, the examiner operates the operation unit 76 to shift to a laser irradiation mode for performing laser irradiation. Here, the control unit 70 performs laser irradiation based on the set irradiation region.

  The control unit 70 controls the observation optical system 200 and acquires a fundus front image. Then, the control unit 70 displays the fundus front image acquired as needed on the monitor 75 in real time. The fundus front image associated with the analysis map is used as a reference image for tracking the laser beam.

  When the examiner operates the irradiation start key of the operation unit 76, the control unit 70 can perform laser irradiation on the set laser irradiation region G. The photocoagulation laser device 400 oscillates a therapeutic laser beam (for example, a wavelength of 532 nm). This laser beam is introduced into the optical fiber 401 and emitted from the emission end 401a. The laser beam emitted from the emission end 401 a is reflected by the dichroic mirror 30 and is applied to the fundus oculi Ef via the optical scanner 108 and other optical members of the measurement optical system 106.

  The control unit 70 controls the optical scanner 108 and aligns the scanning position of the optical scanner 108 with the irradiation area E. Then, the control unit 70 controls the laser device 400 to irradiate the irradiation region G with laser light. When there are a plurality of irradiation regions, the control unit 70 sequentially irradiates each irradiation region with laser light.

  At this time, the control unit 70 does not necessarily irradiate the entire irradiation region E with the laser, and may irradiate the laser light having a dot pattern set at a predetermined interval. Further, as a laser irradiation method, the control unit 70 may cause the optical scanner 108 to perform a raster scan and irradiate the laser beam when the scanning position reaches the irradiation region G.

  At the time of laser irradiation, the control unit 70 sets a fundus image associated with the analysis map as a reference image, and detects a relative position with the fundus image acquired at any time. And the control part 70 irradiates a laser beam to eyes based on the set irradiation position information by controlling operation | movement of a laser light source and the optical scanner 108. FIG. That is, the scanning position by the optical scanner 108 is corrected based on the detection result (laser light tracking) so that the set region on the fundus oculi Ef can be irradiated even if the eye moves. Thereby, the laser irradiation position is corrected. For example, the control unit 70 detects a shift related to the surface direction (XY direction) of the fundus between the associated fundus front image and the fundus image acquired at any time, and the light is corrected so that the detected shift is corrected. The scanning position of the scanner 108 is corrected.

  The scanning speed by the optical scanner 108 at the time of laser irradiation and the scanning speed at the time of image acquisition by the OCT optical system 100 may be changed. For example, the scanning speed at the time of laser irradiation is made slower than the scanning speed at the time of image acquisition by the OCT optical system 100.

  With the configuration as described above, it is possible to irradiate a therapeutic laser using a layer analysis result of a tomographic image acquired by OCT. As a result, laser treatment based on information that is difficult to visually recognize in the observation of the fundus front image is possible, and a good surgical result is obtained.

  For example, as described above, the death of photoreceptor cells due to laser irradiation can be reduced by using the analysis result relating to the state of photoreceptor cells. This contributes to postoperative visual function recovery.

  Also, when performing a laser test shot to confirm the photocoagulation state, if the region where the photoreceptor cells are not functioning can be determined in advance as described above, the region where the visual function is not functioning is irradiated. , Test shooting can be performed effectively.

  In the above description, the IS / OS is detected to analyze the visual function, but the present invention is not limited to this. For example, the control unit 70 detects a ganglion cell layer and an optic nerve fiber layer by image processing, and determines whether or not the layer thickness is normal. And the control part 70 acquires the analysis map regarding a visual function based on the determination result in each position.

  Further, the control unit 70 may analyze the visual function by measuring change information of tomographic images before and after stimulating the fundus. In this case, the apparatus is provided with a stimulation light source (for example, a visible light source) that emits light that stimulates the fundus.

  For example, the control unit 70 controls the light source for stimulation, and acquires a tomographic image before stimulation and a tomographic image after stimulation. Then, the luminance change between the tomographic image before stimulation and the tomographic image after stimulation is obtained. The control unit 70 determines whether or not the visual function is normal using the luminance change amount. Note that the control unit 70 may acquire tomographic images from before the stimulation until a predetermined time after the end of the stimulation as needed, and make a determination regarding the visual function based on the acquired tomographic image.

  In the above description, the control unit 70 may superimpose the fundus front image of the moving image acquired by the observation optical system 200 as needed and the analysis map. Such a moving image is effective when the surgeon determines a laser irradiation area while observing the moving image and irradiates the fundus with the laser.

  Here, the control unit 70 sets a fundus image associated with the analysis map as a reference image, and detects a relative position with the fundus image acquired at any time. Based on the detection result, the control unit 70 corrects the display position of the analysis map so that the correspondence between the fundus region and the analysis map matches even if the eye moves.

  For example, the control unit 70 moves the analysis map based on the detected amount of eye position deviation by image processing, and corrects the display position by the amount of position deviation, thereby moving the eye while observing the front image. In addition, a certain analysis map can be observed on the fundus front image.

  In addition, when the graphic indicating the irradiation prohibited area and / or the laser irradiation area is superimposed on the front image (moving image), the control unit 70 determines the fundus even if the eye moves, based on the detection result of the relative position. You may make it correct | amend the display position of a graphic so that the correspondence of a site | part and a graphic may correspond. Of course, even when both the above-described analysis map and graphic are superimposed on the front image, the display position can be corrected.

  In the tracking, various image processing methods (a method using various correlation functions, a method using Fourier transform, and a method based on feature point matching) are used as a method for detecting a positional deviation between two images. It is possible.

  For example, the reference image or the observation image (current fundus image) is displaced pixel by pixel, the reference image and the target image are compared, and when both data are the best match (when the correlation is the highest), A method for detecting the direction of displacement and the amount of displacement is conceivable. Further, a method is conceivable in which common feature points are extracted from a predetermined reference image and target image, and the positional deviation direction and the positional deviation amount of the extracted feature points are detected.

  As an evaluation function in template matching, SSD (Sum of Squared Difference) indicating similarity or SAD (Sum of Absolute Difference) indicating difference may be used as the evaluation function.

  In the above configuration, the OCT optical system and the laser irradiation optical system share a part of the optical system (for example, an optical scanner), but the present invention is not limited to this. For example, a first optical scanner for an OCT optical system is provided, and measurement light is scanned by the first optical scanner. A second optical scanner for the laser irradiation optical system is provided, and the therapeutic laser light is scanned by a second optical scanner different from the first optical scanner.

  Further, the OCT apparatus and the laser photocoagulation apparatus may be arranged in different cases. For example, a laser irradiation area is set in advance using a tomographic image acquired by an OCT apparatus, and the set laser irradiation information is input to the laser photocoagulation apparatus. The laser photocoagulation apparatus executes laser irradiation based on the input irradiation information. The laser irradiation information is input to the photocoagulation apparatus through a communication line such as a LAN, for example. In this way, the analysis result of a single OCT apparatus can be used. Of course, the laser photocoagulator may receive the tomographic image, and the laser irradiation position may be set by analyzing the received tomographic image. Alternatively, the laser photocoagulator may receive the analysis result, and the irradiation position may be set by superimposing the received analysis result and the fundus front image.

  Note that the fundus front image acquired by the fundus observation system provided in the photocoagulation apparatus and the analysis map (or the fundus front image associated with the analysis map) may differ in imaging magnification, aspect ratio, and the like. In this case, the control unit 70 corrects the imaging magnification and aspect ratio of the analysis map (or the fundus front image associated with the analysis map) by image processing in accordance with the fundus front image acquired by the fundus observation system. preferable.

  In addition, as the observation optical system 200 arranged in the laser photocoagulator, a slit lamp that can be directly viewed by an operator may be arranged. Further, an in-field display unit may be provided for an operator looking into the eyepiece. In this case, a beam combiner is provided between the eyepiece of the slit lamp and the patient's eye. The display image displayed on the in-field display unit is reflected by the beam combiner and travels toward the eyepiece. Thereby, the surgeon can visually recognize the observation image and the display image of the slit lamp.

  In this case, the control unit 70 may display the analysis result acquired as described above on the in-field display unit, and superimpose and display the fundus observation image and the analysis result. In this way, the examiner can determine the laser irradiation region with reference to the analysis result of the OCT while viewing the fundus image with the slit lamp.

  In the above description, a configuration in which a tomographic image of the fundus is acquired by the OCT device and the laser is emitted to the fundus based on the analysis result of the acquired tomographic image is illustrated, but the present invention is not limited to this. Any configuration may be used as long as it obtains a tomographic image of the eye with an OCT device and irradiates the eye tissue with a laser based on the analysis result of the obtained tomographic image. For example, a configuration may be adopted in which a tomographic image of the anterior segment is acquired by an OCT device and a laser is irradiated on the anterior segment based on the analysis result of the acquired tomographic image.

  In the above description, the analysis result is a combination using an OCT device. However, the present invention is not limited to this, and an analysis result of another model may be used. For example, it is conceivable to use the result of a perimeter.

It is a schematic block diagram explaining the structure of the ophthalmologic imaging device which concerns on this embodiment. It is an example of the tomographic image obtained by the front image obtained by a front observation optical system, and an OCT optical system. It is an example which shows the luminance distribution in the state where IS / OS remains, and the luminance distribution in the state where IS / OS has disappeared. It is a figure which shows the analysis result of a tomographic image. It is a figure which shows the display screen at the time of displaying an analysis map and an irradiation prohibition area | region on a fundus front image, and a laser irradiation area | region being set.

70 Control Unit 72 Memory 75 Monitor 76 Operation Unit 100 Optical Coherence Tomography (OCT Optical System)
108 optical scanner 200 front observation optical system 300 fixation target projection unit 400 photocoagulation laser apparatus

Claims (6)

A treatment laser light source; and deflection means for deflecting laser light emitted from the treatment laser light source with respect to the fundus of the patient's eye, and an irradiation optical system for irradiating the treatment site on the patient's eye fundus;
Irradiation position acquisition means for acquiring irradiation position information of a therapeutic laser on the patient's eye fundus based on an OCT image of the patient's eye fundus captured by an optical coherence tomography device before the laser light is irradiated;
Laser control means for irradiating the patient's eye fundus with laser light based on the irradiation position information acquired by the irradiation position acquisition means by controlling the operations of the laser light source and the deflection means;
With
The optical coherence tomography device is arranged as a housing different from the fundus photocoagulation laser device. The fundus photocoagulation laser device acquires an analysis result based on the OCT image from the optical coherence tomography device,
The fundus photocoagulation laser device according to claim 1, wherein the irradiation position acquisition unit acquires irradiation position information of a treatment laser on the patient's fundus using the acquired analysis result. The fundus photocoagulation laser device according to claim 2, wherein the analysis result is an analysis result obtained based on a layer detection result for the OCT image. The fundus photocoagulation laser device acquires the OCT image from the optical coherence tomography device,
The fundus photocoagulation laser device according to claim 1, wherein the irradiation position acquisition unit acquires irradiation position information of a treatment laser for the patient's fundus by analyzing the OCT image. An observation optical system for observing the fundus front image of the patient's eye;
Image processing means for matching an OCT front image based on the OCT image and a fundus front image acquired by the observation optical system;
The fundus photocoagulation laser device according to claim 1, comprising: The fundus photocoagulation laser apparatus according to claim 1, wherein the irradiation position acquisition unit sets an irradiation prohibited region from an OCT front image based on the OCT image.