Slit-lamp microscope, slit-lamp microscope imaging unit, and ophthalmic laser treatment device

Abstract

Provided are a slit-lamp microscope, a slit-lamp microscope imaging unit, and an ophthalmic laser treatment device, each comprising: a light-projecting optical system disposed in a first relay optical system, provided outside an optical path of the first relay optical system, and including a light source that emits imaging light, a slit section that forms the imaging light into a slit shape, and a coupling section that couples a light-projecting optical path of the imaging light to the optical path of the first relay optical system such that the imaging light having passed through the slit section irradiates an eye to be examined through an objective lens; a light-receiving optical system disposed in a second relay optical system, and including a separation section that separates a light-receiving optical path of the imaging light from an optical path of the second relay optical system, an imaging element that is disposed on the light-receiving optical path to receive the imaging light, and a restriction means that restricts a light-receiving region for the imaging light to a portion of the imaging element; and a scanning means that scans an irradiation position of the imaging light on the eye to be examined, and moves a position of the light-receiving region relative to the imaging element in synchronization with the irradiation position.

Description

Slit lamp microscope, imaging unit for slit lamp microscope, and ophthalmic laser treatment apparatus

[0001] The present disclosure relates to an ophthalmic slit lamp microscope, an observation unit for a slit lamp microscope, and an ophthalmic laser treatment apparatus.

[0002] In ophthalmic examinations, slit lamp microscopes are widely used. As a typical slit lamp microscope, there has been known an apparatus including: an illumination unit that projects illumination light (slit light) to an examinee's eye; and an observation unit which is a binocular microscope unit, and which enables direct observation of an examinee's eye by binocular stereopsis.

[0003] Patent Document 1 discloses an apparatus in which an observation unit is connected to a digital camera, and the examinee's eye can be observed by both image observation via an image captured by the digital camera and direct observation via an eyepiece. In the apparatus of Patent Document 1, an auxiliary illumination unit is arranged between the illumination unit and the examinee's eye. Since the auxiliary illumination unit illuminates an observation region including the periphery of the slit light irradiated region, an image capturing both the observation region irradiated with the slit light and the peripheral region illuminated with the auxiliary illumination light is captured by the digital camera.

[0004] As disclosed in Patent Document 2, a slit lamp microscope is also used as an observation system for an ophthalmic laser treatment apparatus. A slit lamp microscope is used for an examiner, who is an operator, to observe a treatment site and determine an irradiation position of laser light.

[0005] Japanese Patent Application Laid-Open No. 2012-249700 Japanese Patent Application Laid-Open No. 2017-124044

[0006] When observing the inside of an eyeball with a slit lamp microscope, illumination and observation may be performed via a contact lens (see, for example, Patent Document 2). However, in the configuration disclosed in Patent Document 1, illumination light (slit light) or auxiliary illumination light is reflected by the contact lens to generate unnecessary light (called ghost light or the like), and the unnecessary light tends to be reflected in an image.

[0007] This disclosure is made in view of the problems of the prior art, and aims to provide an ophthalmic slit lamp microscope, an imaging unit for a slit lamp microscope, and an ophthalmic laser treatment device that allow for good observation of the eye under examination both with the naked eye and in images.

[0008] A slit lamp microscope according to a first aspect of the present disclosure comprises an observation unit having an objective lens, binocular eyepieces, and a pair of relay optical systems provided between the objective lens and the eyepieces, respectively, and an illumination unit that irradiates illumination light onto the eye to be examined from outside the observation unit, wherein the illumination optical system is disposed in a first relay optical system which is one of the pair of relay optical systems, and is provided outside the optical path of the first relay optical system, and includes a light source that emits photographic light, a slit portion that forms the photographic light in a slit shape, and the photographic light that has passed through the slit portion is irradiated towards the eye to be examined through the objective lens The system includes a light-emitting optical system including a coupling unit which couples the light-emitting optical path of the photographic light with the optical path of the first relay optical system, and a light-receiving optical system disposed in a second relay optical system which is the other of the pair of relay optical systems, which includes a separation unit which separates the light-receiving optical path of the photographic light from the optical path of the second relay optical system, an image sensor disposed on the light-receiving optical path which receives the photographic light, and a limiting means which limits the light-receiving area of ​​the photographic light to a part of the image sensor, and a scanning means which causes the eye under examination to scan the irradiation position of the photographic light and moves the position of the light-receiving area relative to the image sensor in synchronization with the irradiation position.An imaging unit for a slit lamp microscope according to a second aspect of the present disclosure is an imaging unit for a slit lamp microscope to be attached to a slit lamp microscope comprising: an observation unit comprising an objective lens; a pair of relay optical systems provided between the objective lens and the binocular eyepieces; and an illumination unit for irradiating an eye under examination with illumination light from outside the observation unit, wherein the imaging unit comprises a light source that emits photographic light, a slit portion that forms the photographic light in a slit shape, and the photographic light that has passed through the slit portion passes through the objective lens The ophthalmic laser treatment apparatus comprises: a light-emitting optical system including a coupling unit which couples the light-emitting optical path of the photographic light to the optical path of the first relay optical system so that it is irradiated toward the eye under examination; and a light-receiving optical system disposed in a second relay optical system which is the other of the pair of relay optical systems, comprising a separation unit which separates the light-receiving optical path of the photographic light from the optical path of the second relay optical system; an image sensor disposed on the light-receiving optical path which receives the photographic light; and a limiting means which limits the light-receiving area of ​​the photographic light to a part of the image sensor; and a scanning means which scans the irradiation position of the photographic light in the eye under examination and moves the position of the light-receiving area relative to the image sensor in synchronization with the irradiation position. The ophthalmic laser treatment apparatus according to a third aspect of the present disclosure comprises at least one of the slit lamp microscope according to the first aspect and the imaging unit for the slit lamp microscope according to the second aspect.

[0009] This is a drawing showing the overall configuration of the apparatus according to the first embodiment. This is a side view showing the optical system of the apparatus according to the first embodiment. This is a top view of the internal structure of the observation unit according to the first embodiment, seen from above. This is a rear view of the internal structure of the imaging unit according to the first embodiment, seen from the operator's side. This is a diagram showing the optical chopper arranged in the imaging unit according to the first embodiment. This is a block diagram showing the control system of the apparatus according to the first embodiment. This is a fundus image, which is an example of an image captured by the apparatus according to the first embodiment. This is a side view showing the overall configuration and optical system of the apparatus according to the second embodiment. This is a timing chart for explaining the operation of the apparatus according to the second embodiment.

[0010] [Overview] Typical embodiments of this disclosure are described below. Unless otherwise specified, the apparatus in the embodiments will be described as a slit lamp microscope. Currently, slit lamp microscopes available on the market are mainly of one of two basic configurations: the so-called Haag type (Goldman type) or the Zeiss type. The technology of this disclosure is applicable to apparatus of either of these types. The items classified in < > below may be used independently or in relation to each other. [First Embodiment]

[0011] <Slit Lamp Microscope> The slit lamp microscope of this disclosure comprises an observation unit and an illumination unit. The observation unit comprises an objective lens, binocular eyepieces, and a pair of relay optical systems provided between the objective lens and the eyepieces, respectively. This allows the examiner to observe the eye under examination through the binocular eyepieces. The illumination unit illuminates the eye under examination with slit light from outside the objective lens. The illumination unit may include, for example, a light source (preferably a visible light source) and an aperture (e.g., a slit) for shaping the light from the light source into a predetermined shape.

[0012] <Imaging Unit> The slit lamp microscope of this disclosure further comprises a light projection optical system, a light receiving optical system, and a scanning means. These configurations allow imaging of the observation area, including the area around the slit light irradiation site. As a result, image observation (also called indirect observation) via the captured image becomes possible. The light projection optical system, the light receiving optical system, and the scanning means may be housed in a common housing as an imaging unit.

[0013] The light projection optical system is located in the first relay optical system, which is one of a pair of relay optical systems. The light projection optical system includes at least a light source, a slit section, and a coupling section. The light source is located outside the optical path of the first relay optical system and emits photographic light. In this embodiment, the photographic light is used to acquire moving images or still images, including live images. The slit section forms the photographic light in a slit shape. The coupling section couples the light projection path of the photographic light, which has passed through the slit section, to the optical path of the first relay optical system so that the photographic light passes through the objective lens and is directed toward the eye under examination.

[0014] The light-receiving optical system is located in the second relay optical system, which is the other of a pair of relay optical systems. The light-receiving optical system includes at least a separation unit, an image sensor, and a limiting means. The separation unit separates the light-receiving optical path of the photographic light from the optical path of the second relay optical system. The light-receiving optical path is the optical path of the return light of the photographic light that has been reflected and scattered by the eye under examination. The image sensor is located on the light-receiving optical path and receives the photographic light. The limiting means restricts the light-receiving area of ​​the photographic light to a part of the image sensor. The limiting means may form the light-receiving area in the shape of a slit. The limiting means may be, for example, a slit unit, a mechanical shutter, or an electronic shutter. In the case of an electronic shutter, the image sensor may also serve as the limiting means.

[0015] The scanning means scans the irradiation position of the imaging light in the eye under examination, and simultaneously moves the position of the light-receiving area on the image sensor in synchronization with the irradiation position of the imaging light. In other words, on the observation surface, the irradiation position of the imaging light and the position corresponding to the light-receiving area (a position approximately conjugate to the light-receiving area) are moved while maintaining a state of coincidence. This suppresses unwanted light (ghost light), such as reflected light from contact lenses or internal reflections from the observation unit, from being received by the image sensor. Therefore, it is possible to prevent unwanted light from appearing in the image. Accordingly, the slit lamp microscope of this disclosure can achieve good results in both direct observation and image observation.

[0016] Furthermore, the position of the light source for imaging and the position of the light-receiving area may be moved simultaneously by a common driver (drive unit). This allows the scanning means to synchronize the movement of the light source for imaging and the position of the light-receiving area.

[0017] <Specific Example Using an Optical Chopper> A common rotating disc (optical chopper) may be provided, with multiple slit openings formed along its circumference. The optical chopper serves as both the slit section and the limiting means. By using an optical chopper, the position of the light-emitting area and the position of the light-receiving area can be easily synchronized. Therefore, for example, even when a CMOS is used as the image sensor, if an optical chopper is used, it is not necessary to synchronize the exposure timing of each area by the CMOS's rolling shutter with the position of the light-emitting area, thus simplifying control. Furthermore, the coupling section and the separation section may each include multiple deflection members arranged symmetrically. When the light-emitting path and the light-receiving path pass opposite each other across the rotation axis of the rotating disc, the direction of movement of the slit openings is opposite between the light-emitting path and the light-receiving path. Multiple deflection members arranged symmetrically in the coupling section and the separation section rotate the orientation of the image of each slit opening in opposite directions. This allows the position and orientation of the images from each slit aperture to be aligned on the eye under examination.

[0018] When both the connecting and separating parts are composed of multiple deflection members, it becomes easier to secure the distance between the light-emitting path and the light-receiving path. Therefore, when using an optical chopper, it becomes easier to secure space for positioning the optical chopper.

[0019] Furthermore, the position of the light source for imaging and the position of the region on the image sensor that receives reflected light may be moved independently. In this case, a processor that controls the movement of both to be synchronized may be included in the scanning means.

[0020] <Wavelength band of imaging light> The light source of the projection optical system may emit infrared light as imaging light. This reduces the likelihood of the subject experiencing glare when observing the eye using images. Furthermore, when used as an observation system for ophthalmic laser treatment devices, infrared observation images can be used for treatment. Infrared observation images may contain information that cannot be obtained through direct observation, potentially leading to more effective treatment.

[0021] The light-emitting optical system may further include a second light source that emits visible light. The visible light emitted from the second light source may be white light. However, it is not necessarily limited to this, and the second light source may emit monochromatic light or light obtained by mixing multiple monochromatic lights. Also, the image sensor of the light-receiving optical system may be sensitive to both infrared light and visible light. For example, in laser treatment, an aiming light is sometimes used to indicate the position where the treatment light will be irradiated, and the observation site is observed. In this case, since the image sensor is sensitive to both visible light and infrared light, the aiming light spot can be confirmed on the image regardless of whether the image is taken with infrared light or white light. The image sensor may be, for example, a color CMOS or a color CCD. The image sensor can be used for both infrared light and visible light imaging, which can reduce the cost of the equipment. However, the light-receiving optical system may have separate image sensors corresponding to infrared light and visible light, respectively.

[0022] <Method for attaching and detaching the imaging unit> Next, if the light-emitting optical system, light-receiving optical system, and scanning means are housed in a common housing as an imaging unit, the imaging unit may be detachable from the slit lamp microscope. The imaging unit may be detachable via the mounting portion of the slit lamp microscope.

[0023] The mount section of the slit lamp microscope detachably connects the eyepiece unit, which includes binocular eyepieces, to the microscope tube, which includes the objective lens. In contrast, the imaging unit may have a connection section for attaching the imaging unit to the mount section.

[0024] Furthermore, the imaging unit may have a second mounting section on the opposite side of the connection section for detachably connecting an eyepiece unit. The second mounting section may have the same configuration as the mounting section of a slit lamp microscope. This allows an eyepiece unit suitable for a slit lamp microscope to be reused and attached to the second mounting section.

[0025] [Second Embodiment] The slit lamp microscope according to the second embodiment comprises at least an observation unit, an imaging unit, a detection means, and a control means.

[0026] The observation unit has an objective lens and an eyepiece. The observation unit is used for the examiner to directly observe the eye under examination through the objective lens and eyepiece. The imaging unit includes a light projection optical system and a light receiving optical system. The light projection optical system projects imaging light onto the eye under examination. The light receiving optical system has an optical path coupled between the objective lens and the eyepiece, and an image sensor is arranged to receive the imaging light. A detection means detects whether the eyepiece is being looked through. A control means controls the imaging unit based on the output from the detection means.

[0027] According to the slit lamp microscope of the second embodiment, the imaging unit is automatically controlled depending on whether or not the eyepiece is being looked through, making it easier for the operator to smoothly transition between direct observation through the microscope's eyepiece and image observation.

[0028] Various methods can be used to detect whether or not the eyepiece is being looked through. For example, a proximity sensor may be installed at the tip of the eyepiece, or a pressure sensor or force sensor may be installed to detect the load on the eyepiece caused by looking through it. A distance sensor may be installed at a position away from the tip of the eyepiece to detect objects in the vicinity of the tip of the eyepiece. When using a distance sensor, it is possible to attach the sensor to the imaging unit, making it easy to retrofit (add) the imaging unit together with the distance sensor to existing ophthalmic laser treatment devices or slit lamp microscopes. The imaging unit may also have a detection means. For example, the detection means may be capable of detecting whether or not the eyepiece is being looked through without contact. In this case, it is desirable that the detection means be positioned in the imaging unit opposite the operator looking through the eyepiece.

[0029] The light projection optical system may have a switching means for changing the amount of light emitted for imaging. The switching means may switch between turning the light on and off. The switching means may be, for example, a switch for turning on / off the light source that emits the imaging light, or a shutter placed in the optical path of the light projection optical system. In this embodiment, "turning off" means that the amount of light emitted to the eye under examination is zero or sufficiently reduced.

[0030] The control means may control the switching means to turn off (dim) the imaging light when it is detected that the eyepiece is being looked through, and turn on (increase) the imaging light when it is detected that the eyepiece is not being looked through. Since the imaging light is automatically turned off (dimmed) when the examiner looks through the eyepiece, the examiner does not need to manually switch the lighting each time they transition from image observation to direct observation through the eyepiece, making it easier to transition to direct observation seamlessly. Also, since the imaging light is automatically turned on (increased) when the examiner no longer looks through the eyepiece, it is also easy to transition seamlessly from direct observation through the eyepiece to image observation.

[0031] In this case, the light projection optical system has a scanning means for scanning the imaging light across the eye under examination, and the control means may keep the scanning means running regardless of whether the imaging light is on or off. This eliminates the need to start the scanning means when transitioning from direct observation to image observation, allowing for a quick start to imaging.

[0032] The slit lamp microscope according to the second embodiment may include an illumination unit that irradiates illumination light onto the eye under examination from outside the observation unit, and a second switching means for switching the illumination light on and off. The control means may control the second switching means to turn on the illumination light when it is detected that the eyepiece is being looked through, and control the switching means to turn off the illumination light when it is detected that the eyepiece is not being looked through. Since the illumination light is automatically turned on when the examiner looks through the eyepiece, the examiner does not need to manually switch the illumination each time they transition from image observation to direct observation through the eyepiece, making it easier to transition to direct observation seamlessly.

[0033] The imaging unit according to the second embodiment may be detachable from the slit lamp microscope, similar to the first embodiment.

[0034] [Example] An embodiment of the ophthalmic laser treatment device 1 (hereinafter referred to as "this device") according to this embodiment will be described based on the drawings.

[0035] <Overall Configuration> As shown in Figure 1, the apparatus 1 includes a slit lamp microscope 10 as an observation system. An imaging unit 40 is attached to the slit lamp microscope 10. As will be described in detail later, in this embodiment, the imaging unit 40 is detachable from the slit lamp microscope 10. However, it is not necessarily limited to this, and the imaging unit 40 may be integrated with the slit lamp microscope 10. In addition to the slit lamp microscope 10 and the imaging unit 40, the apparatus 1 also includes a therapeutic light irradiation unit 60.

[0036] The slit lamp microscope 10 is broadly divided into an observation unit 20 and an illumination unit 30. The slit lamp microscope 10 has a vertical axis V near the patient's eye E and may further have two arms 15 and 16 that are rotatably connected to the vertical axis. Each of the arms 15 and 16 is connected to the observation unit 20 and the illumination unit 30, respectively. As a result, the observation unit 20 and the illumination unit 30 may be able to rotate independently in the horizontal direction with respect to the vertical axis V to which their respective arms are fixed. Consequently, the direction of illumination of the slit light to the patient's eye E and the observation direction can be changed at will.

[0037] <Optical System of Slit Lamp Microscope> Next, the optical system of this device 1 will be explained with reference to Figures 2 to 5 as appropriate. First, the optical system of the slit lamp microscope 10 will be explained.

[0038] <Illumination Unit> As shown in Figure 2, the illumination unit 30 irradiates the patient's eye E with illumination light from outside the observation unit 20. In this embodiment, visible light is irradiated as illumination light. As shown in Figure 2, the illumination unit 30 has an illumination optical system 30a. The illumination optical system 30a includes a light source 31, a condenser lens 32, a slit 33, a lens group 34, and a mirror 35, etc. In this embodiment, the illumination shape is formed into a slit shape by the slit 33. However, the illumination shape is not necessarily limited to a slit shape. Also, the illumination shape may be changeable by providing, for example, a variable-shape slit plate or a variable-shape aperture. After passing through the slit 33, the illumination light is irradiated onto the patient's eye E via the lens group 34 and the mirror 35. In the example of Figure 2, the illumination light is irradiated along the optical axis L1. In this embodiment, the illumination light is irradiated from below the patient's eye E, but this is not necessarily limited. For example, instead of the mirror 35, a segmented mirror may be provided, positioned at approximately the same height as the patient's eye E, to illuminate the patient's eye E from the same height.

[0039] <Observation Unit> The observation unit 20 is a binocular microscope unit. The observation unit 20 has an observation optical system 20a.

[0040] Figure 3 is a plan view of the internal structure of the observation unit 20, viewed from above. As shown in Figure 3, the observation optical system 20a includes an optical axis L2R for presenting the observation image to the operator's right eye EoR and an optical axis L2L for presenting the observation image to the operator's left eye EoL. The observation optical system 20a includes an objective lens 21, a variable magnification optical system 22 (22R, 22L), an erecting prism group 23 (23R, 23L), an eyepiece lens 24 (24R, 24L), etc. The operator can look through the eyepiece lens 24 to confirm the observation area of ​​the patient's eye E located on a predetermined observation surface I. The spot of aiming light emitted from the treatment light irradiation unit 60 can also be confirmed along with the observation area.

[0041] The observation unit 20 is broadly divided into an objective lens unit 20b and an eyepiece unit 20c. The observation optical system 20a is arranged across the objective lens unit 20b and the eyepiece unit 20c. In detail, the objective lens 21 and the variable magnification optical system 22 are located in the objective lens unit 20b. The erecting prism group 23 and the eyepiece 24 are located in the eyepiece unit 20c.

[0042] In this embodiment, the left and right pair of optical systems between the objective lens 21 and the eyepiece lens 24 are referred to as relay optical systems for convenience. Of the pair of relay optical systems, the optical system including the variable magnification optical system 22L and the erecting prism group 23L is referred to as the first relay optical system. Also, of the pair of relay optical systems, the optical system including the variable magnification optical system 22R and the erecting prism group 23R is referred to as the second relay optical system.

[0043] <Imaging Unit> The imaging unit 40 includes a light-emitting optical system 40a and a light-receiving optical system 40b. In this embodiment, the imaging unit 40 images the observation area of ​​the patient's eye E using a slit-scan method. This allows the observation area to be observed through the image.

[0044] FIG. 4 is a diagram showing the internal structure of the imaging unit 40 as viewed from the operator side. The projection optical system 40a is arranged in the first relay optical system. The projection optical system 40a includes light sources 41 and 42, a collimating lens 43, a chopper 44, a lens group 45L, and a coupling portion 46L. The light source 41 emits infrared light as imaging light. The light source 42 emits white light as imaging light. In this embodiment, either the light source 41 or the light source 42 is selectively turned on. However, the imaging unit 40 does not necessarily need to include both the light source 41 and the light source 42 as imaging light sources, and may include only one of them.

[0045] The light receiving optical system 40b includes a separation portion 46R, a lens group 45R, a chopper 44, and an image sensor 49. In this embodiment, the image sensor 49 is a color CMOS that has sensitivity to both visible light and infrared light.

[0046] The imaging light travels along the optical axis L4L. The optical path (projection optical path) of the projection optical system 40a is coupled to the optical path of the first relay optical system by the coupling portion 46L. In this embodiment, the projection optical path is coupled between the variable magnification optical system 22R and the erecting prism group 23R. As a result, the imaging light is irradiated toward the patient's eye E through the objective lens 21. Further, the optical path (light receiving optical path) of the light receiving optical system 40b is coupled to the optical path of the second relay optical system by the separation portion 46R. In this embodiment, the light receiving optical path is coupled between the variable magnification optical system 22L and the erecting prism group 23L. As a result, the return light of the imaging light from the patient's eye E is separated from the optical path of the second relay optical system and guided to the light receiving optical path. The imaging light travels along the optical axis L4R.

[0047] As shown in Figure 5, the chopper 44 is a rotating disc 44a with multiple slit-shaped openings 44b formed along its circumference. In this embodiment, the chopper 44 has an even number of openings 44b formed at equal intervals. Therefore, each opening 44b has a corresponding opening 44b at a position 180° opposite. The chopper 44 is positioned so that its rotation axis Q is located midway between the light-emitting path and the light-receiving path (midway between the optical axis L4R and the optical axis L4L). In this embodiment, the chopper 44 is positioned near the conjugate position of the observation surface I. However, it is not necessarily limited to this, and by providing a relay system between the chopper 44 and the image sensor 49, both the chopper 44 and the image sensor 49 may be positioned at the conjugate position of the observation surface I. The chopper 44 is rotated by a motor 44c around the rotation axis Q. As the chopper 44 rotates, the irradiation position of the imaging light is scanned on the observation surface I. Furthermore, when one of the multiple apertures 44b crosses the light-emitting path, the aperture located 180° opposite to that aperture crosses the light-receiving path. The apertures 44b positioned on the light-receiving path restrict the area on the image sensor 49 that receives reflected light. This area is also moved as the chopper 44 rotates. In this embodiment, as the chopper 44 rotates, the area on the image sensor 49 that receives reflected light moves in synchronization with the scanning of the irradiation position.

[0048] Here, in the present embodiment, the moving directions of the aperture 44b on the light projection optical path and the aperture 44b on the light receiving optical path are opposite to each other. In contrast, the combining section 46L and the separating section 46R align the positions and moving directions of the images of the two apertures 44b on the observation plane I. That is, the combining section 46L and the separating section 46R each have two mirrors (deflecting members 47L, 48L, 47R, 48R) and are arranged symmetrically left and right. In the present embodiment, the deflecting members 48L and 48R respectively arranged on the optical axes L2L and L3R are half mirrors. The deflecting members 48L and 48R can reflect visible light and infrared light, and transmit at least visible light. In the present embodiment, passing through the mirror 48L or the mirror 48R reverses the relationship of the moving direction between the images of the two apertures 44b, so that the images of the two apertures 44b are aligned on the observation plane I. Accordingly, the observation site of the patient's eye E is imaged by the slit scanning method. Unwanted light generated outside the observation plane I (for example, ghost light caused by reflection on a contact lens, internal reflection within an objective lens unit, etc.) is blocked by the chopper 44 and is less likely to be received by the image sensor 49, so that unwanted light can be prevented from being reflected in the captured image.

[0049] Furthermore, in the present embodiment, since the combining section 46L and the separating section 46R are provided, the distance between the light projection optical path and the light receiving optical path is increased relative to the distance between the optical paths of the two relay optical systems, so that sufficient space for arranging the chopper 44 is secured.

[0050] <Internal Display Section> The imaging unit 40 of the present embodiment further includes an internal display section 50. The internal display section 50 displays an image for an operator via an eyepiece 24. As shown in FIG. 2, the internal display section 50 includes a display 53, a lens 52, and a half mirror 51. As the display 53, for example, an LCD with a backlight may be used. In the present embodiment, an image is projected onto the operator's right eye EoR looking through the right eyepiece 46R. The internal display section 50 functions as a so-called head-up display (HUD). The internal display section 50 may display information such as various images and texts for assisting irradiation of therapeutic light, for example.

[0051] <Therapeutic Light Irradiation Unit> The therapeutic light irradiation unit 60 irradiates laser light that produces therapeutic effects as therapeutic light. The therapeutic light irradiation unit 60 also emits a targeting laser beam (hereinafter simply referred to as "targeting light") that indicates the position where the therapeutic light is irradiated (i.e., the position of the irradiation spot). Details are omitted, but the therapeutic light irradiation unit 60 in this embodiment has laser light sources corresponding to the therapeutic light and the targeting light. The therapeutic light irradiation unit 60 also includes an optical system for adjusting the energy amount of the therapeutic light, the spot size, etc., a safety shutter, etc.

[0052] The therapeutic light or aiming light emitted from the therapeutic light irradiation unit 60 is reflected by a dichroic mirror 61 positioned between the objective lens unit 20b and the patient's eye E, and travels along the optical axis L3. The therapeutic light or aiming light is then irradiated onto the tissue of the patient's eye E via the contact lens CL. In this case, the contact lens CL is held by the operator and is positioned either in contact with the cornea or slightly separated from it.

[0053] <Attachment / Detachment Mechanism> Next, the mechanism for attaching and detaching the imaging unit 40 to the slit lamp microscope 10 will be described. Many slit lamp microscopes currently available on the market have a mount formed on the housing that houses the objective lens and variable magnification optical system for attaching the eyepiece unit detachably, and these devices may be interchangeable between devices from different manufacturers. Therefore, in this embodiment, a connection part is formed on the surface of the housing of the imaging unit 40 that contacts the objective lens unit 20a, to fit such a mount. This connection part is formed in the same shape as the connection part formed on the eyepiece unit 20c to fit the mount of the objective lens unit 20b. Furthermore, a mount (second mount) with the same shape as the mount of the objective lens unit 20b is formed on the surface of the imaging unit 40 that contacts the objective lens unit 20a, and the eyepiece unit 20c is attached to it. With the above structure, the imaging unit 40 can be easily attached to existing slit lamp microscopes.

[0054] <Control System> Next, the control system will be described with reference to Figure 6. In this embodiment, the imaging unit 40, the slit lamp microscope 10, and the therapeutic light irradiation unit 60 each have their own independent control system and power supply system and operate independently of each other. At least the control system and power supply system of the imaging unit 40 are independent of the slit lamp microscope 10 and the therapeutic light irradiation unit 60, so the imaging unit 40 can be easily retrofitted (added) to existing ophthalmic laser treatment devices or slit lamp microscopes and used.

[0055] The device 1 has a first control unit 70, a second control unit 80, and a third control unit 80. The first control unit 70 is connected to each part of the slit lamp microscope 10. The second control unit 80 is connected to each part of the therapeutic light irradiation unit 60.

[0056] The first control unit 70 is responsible for controlling the slit lamp microscope 10 and the therapeutic light irradiation unit 60. For example, the irradiation control of the slit light from the illumination unit 30 is performed by the first control unit 70. A first operation unit 71 is connected to the first control unit 70. The first operation unit 71 may be one or more input devices such as various buttons, a touch panel, a mouse, and a keyboard. In this embodiment, the first operation unit 71 is used at least for inputting operations to turn the irradiation of illumination light (slit light) by the illumination unit 30 on / off.

[0057] The second control unit 80 is responsible for controlling the therapeutic light irradiation unit 60. For example, the second control unit 80 controls the irradiation of therapeutic light and aiming light from the therapeutic light irradiation unit 60. A second operation unit 81 is connected to the second control unit 80. The second operation unit 81 may be an input device as described above. In this embodiment, the second operation unit 81 is used at least for operation input to turn the irradiation of illumination light (slit light) by the illumination unit 30 on / off.

[0058] The third control unit 90 is connected to various parts of the imaging unit 40 and is responsible for the overall control of the imaging unit 40. For example, the third control unit 90 includes a CPU, RAM, ROM, etc. The electrical components of the imaging unit 40 (light sources 41, 42, motor 44c, image sensor 49, and display 51, etc.) are connected to the third control unit 90 and control their operation. In addition, the storage unit 91, the third operation unit 92, and the monitor 95 are connected to the third control unit 90. The third control unit 90 can save images captured by the imaging unit 40 to the storage unit 91 or display them on the monitor 95.

[0059] The images captured by the imaging unit 40 are displayed on the monitor 95, allowing the operator to observe the patient's eye E through the images.

[0060] The third operation unit 92 may be one or more input devices such as various buttons, a touch panel, a mouse, and a keyboard. In this embodiment, the third operation unit 92 is used for at least an operation input that triggers the start of shooting by the imaging unit 40, and an operation input for selecting the wavelength of the shooting light. Furthermore, on / off operation of the display by the internal display unit 50 and responses to information displayed by the internal display unit 50 may also be input via the third operation unit 92. Note that a common device may be used for both the first operation unit 77 and the third operation unit 92.

[0061] <Operation Description> When directly observing the patient's eye E through the eyepiece 24, the operator operates the first control unit 77 to illuminate the eye with illumination light (slit light) from the illumination unit 30. By adjusting the position of the observation unit 20 to the desired observation area in the patient's eye E (alignment), the observation area can be directly observed. At this time, the device 1 can be used for binocular observation. Stereoscopic observation is also possible. When directly observing the patient's eye E through the eyepiece 24, it is desirable that the light sources 41 and 42 of the imaging unit 40 are turned off.

[0062] When observing the patient's eye E via an image captured by the imaging unit 40, the operator operates the third control unit 92 to select the wavelength band and image type to be used for imaging. Next, an operation input that triggers the start of imaging is performed, and imaging is executed. When observing the patient's eye E via an image, it is desirable that the illumination unit 30 be turned off.

[0063] The imaging unit 40 can capture real-time video (live images) using infrared or white light. The captured video is displayed on the monitor 95 as it is being recorded. At this time, the operator can observe the desired area via the image while adjusting the position of the observation unit 20.

[0064] This device 1 can photograph the patient's eye E while irradiating it with aiming light. Since the image sensor 49 is sensitive to both visible light and infrared light, the aiming light spot can be confirmed on the image regardless of whether the image is taken with infrared light or white light. Figure 7 shows an image taken with infrared light while irradiating with aiming light. The aiming light spot Sp is clearly superimposed on the image. The operator can observe a wide area, including the area to be observed, through the good image taken with the slit scan.

[0065] The image captured using infrared light (referred to as an infrared image), as shown in Figure 7, may contain information that cannot be grasped through direct observation. Furthermore, because it uses infrared light for imaging, it is less likely to cause glare to the patient. In addition, since this device 1 can quickly transition to direct observation through the eyepiece 24, the area of ​​interest in the image can be observed using binocular stereoscopic vision. This, for example, may contribute to more effective diagnosis and treatment.

[0066] In this embodiment, the imaging unit 40 can capture images for recording. The images for recording may be captured using either infrared light or white light. The images for recording may be still images or moving images. When an operation that triggers capture is input to the third operation unit 92, the third control unit 90 executes the capture. The captured images are displayed on the monitor 95, for example, and stored in the storage unit 91.

[0067] <Second Embodiment> Next, an ophthalmic laser treatment device 101 according to the second embodiment (hereinafter referred to as "this device 101") will be described. Components identical to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted.

[0068] In the second embodiment, in order to smoothly switch between direct observation and image observation, at least the imaging unit 40 is automatically controlled according to the usage status of the device 101. Specifically, the imaging unit 40 is controlled according to whether or not the operator is looking through the eyepiece 24. As shown in Figure 8, the device 101 according to the second embodiment has a sensor 300 for detecting whether or not the eyepiece 24 is being looked through. In the second embodiment, the sensor 300 is installed in the imaging unit 40.

[0069] In the second embodiment, the sensor 300 may be a distance sensor. In this embodiment, an ultrasonic sensor is used as the distance sensor, which emits ultrasonic waves along arrow So and detects the reflected waves along arrow Sr. However, it is not necessarily limited to this, and for example, an optical distance sensor may be used, or a camera-type device such as a stereo camera or a TOF camera may be used. In this embodiment, when an object is detected by the sensor 300 at a distance approximately the tip of the eyepiece 24, the third control unit 90 determines that the eyepiece 24 is being looked into. By using a distance sensor as the sensor 300, it becomes easy to retrofit (add) the following functions to existing ophthalmic laser treatment devices or slit lamp microscopes. In the second embodiment, the sensor 300 is connected to the third control unit 90.

[0070] <Operation Description> The operation of this device 101 will be described with reference to the timing chart in Figure 9. Unless otherwise specified, for convenience, the irradiation of the aiming light and the driving of the chopper 44 in the shooting unit 40 will be described as always being continuous.

[0071] As shown in Figure 9, the device 101 is equipped with at least four modes: [SL observation] mode, [IR-Live] mode, [COL-STILL] mode, and [COL-Live] mode. Each mode will be explained in the order of the timing chart.

[0072] The [SL observation] mode is a mode in which the operator looks directly into the eyepiece 24 and observes. The [SL observation] mode is automatically set when it is detected that the eyepiece 24 is being looked into based on a signal from the sensor 300. In this case, the light sources 41 and 42 for imaging in the imaging unit 40 are turned off by the third control unit 90 when switching to the [SL observation] mode. Here, if the imaging unit 40 continues scanning the imaging light while the operator is looking into the eyepiece 24 and observing, there is a risk that flickering due to scanning of the imaging light on the observation surface I, or unwanted light due to reflections from the contact lens CL or internal reflections, may be superimposed on the observation image (also called the optical through image) that is observed directly through the eyepiece 24, which may interfere with direct observation. In contrast, when switching to the [SL observation] mode, the light sources 41 and 42 for imaging in the imaging unit 40 are automatically turned off by the third control unit 90. In the apparatus of the second embodiment, the operator manually turns on the light source 31 of the illumination unit 30. This allows the operator to observe the patient's eye clearly through direct observation. In addition, in any of the [IR-Live] mode, [COL-STILL] mode, and [COL-Live] mode, the system transitions to [SL observation] mode when it is detected, based on a signal from the sensor 300, that the eyepiece 24 is being looked into.

[0073] In this embodiment, the third control unit 90 terminates the [SL observation] mode and switches to the [IR-Live] mode when it is detected, based on a signal from the sensor 300, that the eyepiece 24 is not being looked through.

[0074] The [IR-Live] mode is a mode for observation via live images (moving images) using infrared light. The third control unit 90, triggered by the detection from the sensor 300 that the eyepiece 24 is not being looked through, turns on the light source 41 for imaging in the imaging unit 40. This causes infrared light to be emitted as imaging light. Images captured sequentially via the image sensor 49 are displayed on the monitor 95 as needed. At this time, the operator may manually turn off the light source 31 of the illumination unit 30.

[0075] In [IR-Live] mode, infrared light is emitted, which prevents the patient from being unexpectedly dazzled by the automatic illumination of the light source 41.

[0076] In the second embodiment, switching from [IR-Live] mode to [COL-STILL] mode or [COL-Live] mode is performed based on the operation of the third operation unit 92.

[0077] The [COL-STILL] mode is a mode in which a still image in color is captured as an image for recording. Live images (moving images) using infrared light are acquired until an operation that triggers capture is input. When such an operation is input, the third control unit 90 turns off the light source 41 and turns on the light source 42 for a certain period of time (for example, about 100 ms). As a result, white light is irradiated as the imaging light on the observation area of ​​the patient's eye E for a certain period of time. The image captured by the image sensor 49 during that time is acquired as an image for recording. The third control unit 90 saves the image for recording in the storage unit 91. Alternatively, it may be displayed on the monitor 95. After a certain period of time has elapsed since the start of illumination, the third control unit 90 turns on the light source 41 and resumes the acquisition and display of live images (moving images) using infrared light.

[0078] The [COL-Live] mode is a mode in which the image is observed via a live image (moving image) using white light on the monitor 95. The third control unit 90 turns on the light source 42 for shooting in the shooting unit 40. As a result, white light is irradiated as the shooting light. In addition, the images that are successively captured via the image sensor 49 are displayed on the monitor 95 in real time.

[0079] <Modification> In the second embodiment, a case was described in which a distance sensor is used as a sensor to detect whether or not the eyepiece 24 is being looked through, but it is not necessarily limited to this. For example, a capacitive proximity sensor may be provided at the tip of the eyepiece 24, or a pressure sensor may be provided to detect the load generated on the eyepiece 24 when looking through it, or other methods may be used to detect whether or not the eyepiece 24 is being looked through. Furthermore, for example, with a capacitive proximity sensor, the sensor body such as a capacitor is installed in the imaging unit 40, and electrodes are provided at the tip of the eyepiece 24 and the sensor body and electrodes are electrically connected, so that the imaging unit 40 can be retrofitted without significantly changing the configuration of the existing slit lamp microscope.

[0080] In the second embodiment, the on / off switching of the illumination light from the illumination unit 30 (on / off switching of the light source 31) was described as being done manually by the operator, but this is not necessarily limited to this. The on / off switching of the illumination light from the illumination unit 30 may be controlled based on a signal from the sensor 300. In this case, for example, the first control unit 70 and the third control unit 90 may be connected to communicate with each other. The illumination light of the illumination unit 30 may be turned on as a trigger when it is detected that the eyepiece 24 is being looked through based on a signal from the sensor 300 ([SL observation] mode). Alternatively, the illumination light of the illumination unit 30 may be turned off as a trigger when it is detected that the eyepiece 24 is not being looked through based on a signal from the sensor 300 ([IR-Live] mode, [COL-STILL] mode, [COL-Live] mode). When the imaging unit 40 takes an image, the illumination light of the illumination unit 30 is automatically turned off, which allows for good image observation. Furthermore, if the second control unit 80 and the third control unit 90 are connected in a manner that allows for mutual communication, the amount of aiming light may be changed based on the signal from the sensor 300. In other words, the operating state of the therapeutic light irradiation unit 60 may be changed.

[0081] In the second embodiment, the observation mode that switches from the [SL observation] mode to the [IR-Live] mode was fixed when the sensor 300 detected that the eyepiece 24 was not being looked through. However, it may switch to either the [COL-STILL] mode or the [COL-Live] mode, for example. The operator may also be able to pre-select the observation mode that switches from the [SL observation] mode by default. In the second embodiment, the chopper 44 was described as always rotating by the motor 44c. However, it is not necessarily limited to this, and the third control unit 90 may stop driving the chopper 44 when it is detected that the eyepiece 24 is being looked through. Simultaneously, or alternatively, the imaging control (image acquisition control by the image sensor 49) may be stopped. Driving noise and heat generation caused by the imaging unit 40 are reduced during direct observation.

[0082] 1,101 Ophthalmic Laser Treatment Device 10 Slit Lamp Microscope 20 Observation Unit 21 Objective Lens 24 Eyepiece 22,23 Relay Optical System 20 Observation Unit 30 Illumination Unit 40 Imaging Unit 40a Light Projection Optical System 40b Light Receiving Optical System 41 Light Source 44 Optical Chopper 46L Coupling Unit 46R Separation Unit 49 Image Sensor

Claims

1. A slit lamp microscope comprising: an observation unit comprising an objective lens, binocular eyepieces, and a pair of relay optical systems provided between the objective lens and the eyepieces; and an illumination unit that irradiates illumination light onto an eye under examination from outside the observation unit, wherein a light projection optical system disposed in a first relay optical system, which is one of the pair of relay optical systems, comprises: a light source provided outside the optical path of the first relay optical system and emitting photographic light; a slit portion that forms the photographic light in a slit shape; and a coupling portion that connects the light projection optical path of the photographic light to the optical path of the first relay optical system so that the photographic light that has passed through the slit portion is irradiated towards the eye under examination through the objective lens; and a light receiving optical system disposed in a second relay optical system, which is the other of the pair of relay optical systems, comprises: a separation portion that separates the light receiving optical path of the photographic light from the optical path of the second relay optical system; an image sensor disposed on the light receiving optical path and receiving the photographic light; and a limiting means that limits the light receiving area of ​​the photographic light to a part of the image sensor, A slit lamp microscope comprising: a scanning means that scans the irradiation position of the imaging light in the eye under examination and moves the position of the light-receiving area relative to the image sensor in synchronization with the irradiation position.

2. The slit portion and limiting means are a common rotating disc with a plurality of slit openings formed along its circumference, and the connecting portion and the separating portion include a plurality of deflection members arranged symmetrically, as described in claim 1.

3. The slit lamp microscope according to claim 1 or 2, wherein the light source emits infrared light as the imaging light.

4. The slit lamp microscope according to claim 3, wherein the light projection optical system further comprises a second light source that emits visible light, and the image sensor of the light receiving optical system is a color CMOS or color CCD that is sensitive to both infrared light and visible light.

5. An imaging unit for a slit lamp microscope, which is attached to a slit lamp microscope, comprising: an observation unit comprising an objective lens and a pair of relay optical systems provided between the objective lens and the binocular eyepieces, and an illumination unit that irradiates illumination light onto the eye under examination from outside the observation unit, wherein the imaging unit comprises: a light projection optical system disposed in a first relay optical system, which is one of the pair of relay optical systems, and includes: a light source provided outside the optical path of the first relay optical system and emitting photographic light; a slit portion that forms the photographic light in a slit shape; and a coupling portion that connects the light projection optical path of the photographic light to the optical path of the first relay optical system so that the photographic light that has passed through the slit portion is irradiated towards the eye under examination through the objective lens; and a light receiving optical system disposed in a second relay optical system, which is the other of the pair of relay optical systems, and includes: a separation portion that separates the light receiving optical path of the photographic light from the optical path of the second relay optical system; an image sensor disposed on the light receiving optical path and receiving the photographic light; and a limiting means that limits the light receiving area of ​​the photographic light to a part of the image sensor. An imaging unit for a slit lamp microscope comprising: a light-receiving optical system including; and a scanning means that scans the irradiation position of the imaging light in the eye under examination and moves the position of the light-receiving region relative to the image sensor in synchronization with the irradiation position.

6. An ophthalmic laser treatment apparatus comprising at least one of the slit lamp microscope described in claims 1 to 4 and the imaging unit for the slit lamp microscope described in claim 5.

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