Surgical microscope

Abstract

To provide a surgical microscope capable of improving the visibility of a posterior capsule.SOLUTION: The ophthalmologic apparatus includes an illumination optical system 32 that irradiates the patient's eye E with illumination light, and an observation optical system 40 that guides return light from the patient's eye E irradiated with the illumination light through the objective lens 20 to at least one of an imaging device 60 or eyepieces 60 L and 60 R, wherein an illumination optical axis O S of the illumination optical system 32 is inclined with respect to an optical axis O A of the objective lens 20, and the illumination optical system 32 irradiates the patient's eye E with the illumination light without passing through the objective lens 20.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a surgical microscope used in surgery on a patient's eye. [Background technology]

[0002] In cataract surgery, a cloudy lens is removed from a patient's eye (also referred to as the examinee's eye or the operated eye) and an intraocular lens is inserted to replace it. A surgical microscope is used in such cataract surgery (see Patent Document 1). The surgical microscope described in Patent Document 1 includes an illumination optical system that irradiates the patient's eye with illumination light through an objective lens, and a photographing optical system that guides return light from the patient's eye through the objective lens to at least one of an eyepiece and an imaging element. This allows the surgeon to observe the patient's eye through the eyepiece, or to observe an image of the patient's eye displayed on a monitor.

[0003] Furthermore, in the surgical microscope described in Patent Document 1, in order to enable three-dimensional recognition of the patient's eye, the optical axis of the illumination optical system is tilted relative to the optical axis of the photographing optical system (objective lens), and illumination light is irradiated from the illumination optical system through the objective lens onto the patient's eye from an oblique direction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-129623 Summary of the Invention [Problem to be solved by the invention]

[0005] During cataract surgery, after the anterior capsule of a patient's eye is incised and the crystalline lens is removed, the posterior capsule must be polished to ensure that no crystalline lens remains on the posterior side. To prevent rupture of the posterior capsule during this process, it is important to improve the visibility of the posterior capsule (the Y-shaped suture of the crystalline lens on the posterior side) using a surgical microscope. The surgical microscope described in Patent Document 1 improves the three-dimensional effect of the patient's eye by irradiating the patient's eye with illumination light from an illumination optical system through an objective lens at an oblique angle. While this makes the anterior capsule (the Y-shaped suture of the crystalline lens on the anterior side) visible, the visibility of the posterior capsule is insufficient. Therefore, there has been a demand for further improvement in the visibility of the posterior capsule.

[0006] The present invention has been made in view of the above circumstances, and has an object to provide a surgical microscope that can improve the visibility of the posterior capsule. [Means for solving the problem]

[0007] A surgical microscope for achieving the object of the present invention comprises an illumination optical system that irradiates illumination light onto a patient's eye, and an observation optical system that guides return light from the patient's eye irradiated with the illumination light through an objective lens to at least one of an imaging device or an eyepiece, wherein the illumination optical axis of the illumination optical system is inclined with respect to the optical axis of the objective lens, and the illumination optical system irradiates the illumination light onto the patient's eye without passing through the objective lens.

[0008] This surgical microscope can ensure a large illumination angle, which is the inclination angle of the illumination optical axis relative to the optical axis of the objective lens, thereby improving the visibility of the posterior capsule.

[0009] In a surgical microscope according to another aspect of the present invention, the optical axis of the objective lens is parallel to the vertical direction.

[0010] In the surgical microscope according to another aspect of the present invention, when the inclination angle of the illumination optical axis with respect to the optical axis of the objective lens is ω, the inclination angle is 20° < ω < 40°, and when the illumination distance, which is the distance from the patient's eye to the illumination optical system, is L, the illumination distance is 130 mm < L < 330 mm. The rotational angle position of the illumination optical system in the circumferential direction around the optical axis of the objective lens is θ. When viewed from the upper side in the vertical direction, the direction opposite to the direction where the surgeon is located is set as θ = 0°, the direction where the surgeon is located when viewed from the upper side is set as θ = 180°, the right side direction of the surgeon when viewed from the upper side is set as θ = 90°, and the left side direction of the surgeon when viewed from the upper side is set as θ = 270°. In this case, the rotational angle position is within the range excluding 120° ≤ θ ≤ 240°. Thereby, the visibility of the posterior capsule is improved, and it is prevented that the illumination optical system hinders the surgery on the patient's eye by the surgeon.

[0011] In the surgical microscope according to another aspect of the present invention, the rotational angle position is within at least one of the ranges of -30° < θ < 30°, 60° < θ < 120°, and 240° < θ < 300°. Thereby, the visibility of the posterior capsule is improved, and it is prevented that the illumination optical system hinders the surgery on the patient's eye by the surgeon.

[0012] In the surgical microscope according to another aspect of the present invention, the side opposite to the patient's eye side of the illumination optical axis is bent. Thereby, the surgical microscope can be miniaturized.

[0013] In the surgical microscope according to another aspect of the present invention, the side opposite to the illumination optical axis is bent in a direction perpendicular to the vertical direction. Thereby, the surgical microscope can be miniaturized.

[0014] In the surgical microscope according to another aspect of the present invention, it is used for observing the posterior capsule of the patient's eye in cataract surgery.

Advantages of the Invention

[0015] The present invention improves the visibility of the posterior capsule.

Brief Description of the Drawings

[0016] [Figure 1] FIG. 1 is a top view of a surgical microscope. [Figure 2] FIG. 1 is a side view of a surgical microscope. [Figure 3] 10 is an explanatory diagram for explaining the illumination angle and illumination distance of the second illumination optical system. FIG. [Figure 4] FIG. 10 is an explanatory diagram for explaining the rotation angle position of the second illumination optical system. [Figure 5] This is a diagram showing the Y-shaped suture on the lens, which serves as an indicator of the visibility of the posterior capsule. [Figure 6] FIG. 10 is an explanatory diagram for explaining the relationship between the illumination angle and the visibility of the Y-stitch. [Figure 7] FIG. 10 is an explanatory diagram for explaining the relationship between the illumination distance and the visibility of the Y-stitch. [Figure 8] FIG. 10 is an explanatory diagram for explaining the relationship between the rotation angle position and the visibility of the Y-stitch. [Figure 9] 10 is an explanatory diagram for explaining the range of rotation angle positions of the second illumination optical system as viewed from above. FIG. [Figure 10] 10 is an explanatory diagram for explaining a more preferable range of the rotation angle position of the second illumination optical system as viewed from above. FIG. [Figure 11] FIG. 10 is a diagram showing a modified example of the surgical microscope. DETAILED DESCRIPTION OF THE INVENTION

[0017] [Overall configuration of a surgical microscope] Fig. 1 is a top view of a surgical microscope 10. Fig. 2 is a side view of the surgical microscope 10. The Z direction in the figure is parallel to the up-down direction and corresponds to the working distance direction of the surgical microscope 10 (the direction of the optical axis OA of the objective lens 20, which will be described later). The X direction in the figure corresponds to the left-right direction (interpupillary direction) relative to the surgeon or patient (also referred to as the subject), and the Y direction is perpendicular to the XZ direction.

[0018] 1 and 2, a surgical microscope 10 is used for magnifying and observing a patient's eye E (also referred to as a subject) during cataract surgery, for example, of the patient's eye E in a supine position. This cataract surgery involves the steps of incising the anterior capsule CLa of the patient's eye E to remove the crystalline lens CL, polishing the posterior capsule CLb, and inserting an intraocular lens. As will be described in more detail below, this surgical microscope 10 improves the visibility of the posterior capsule CLb before and during cataract surgery.

[0019] The surgical microscope 10 includes an objective lens 20, a dichroic mirror DM, first illumination optical systems 31L and 31R, a second illumination optical system 32, an observation optical system 40, and an imaging device 60. The observation optical system 40 also includes a zoom expander 50. The objective lens 20 and the dichroic mirror DM may be included as part of the observation optical system 40. Although not shown, a front lens for fundus observation may be removably provided between the objective lens 20 and the patient's eye E.

[0020] The objective lens 20 has an optical axis OA parallel to the Z direction (working distance direction) and is disposed at a position facing the patient's eye E. A dichroic mirror DM and first illumination optical systems 31L and 31R are disposed above the objective lens 20 in the Z direction.

[0021] The dichroic mirror DM is provided between the objective lens 20 and the first illumination optical systems 31L and 31R at a position where the optical path of the first illumination optical systems 31L and 31R can be coupled to the optical path of the observation optical system 40. The dichroic mirror DM transmits illumination light incident from the first illumination optical systems 31L and 31R and guides it to the objective lens 20. Furthermore, the dichroic mirror DM is also supplied with return light from the patient's eye E irradiated with illumination light from the first illumination optical systems 31L and 31R, or return light from the patient's eye E irradiated with illumination light from the second illumination optical system 32, via the objective lens 20. The dichroic mirror DM reflects the return light from the patient's eye E, which has entered through the objective lens 20, toward the observation optical system 40.

[0022] The first illumination optical systems 31L and 31R each emit illumination light of a wavelength in the visible region having a color temperature of, for example, 3000 K (Kelvin). As a result, the illumination light from the first illumination optical systems 31L and 31R is irradiated onto the patient's eye E via the dichroic mirror DM and the objective lens 20 (front lens).

[0023] Furthermore, the optical axis OL of the first illumination optical system 31L and the optical axis OR of the first illumination optical system 31R are arranged to be approximately coaxial with the optical axis OA of the objective lens 20. As a result, the first illumination optical systems 31L and 31R illuminate the fundus of the patient's eye E with so-called "0-degree illumination" via the dichroic mirror DM and the objective lens 20 (front lens). As a result, the illumination light is diffusely reflected on the fundus, allowing a retro-illumination image (red reflex) of the fundus to be stereoscopically photographed (observed).

[0024] The first illumination optical systems 31L and 31R can be omitted, in which case a reflecting mirror is disposed in place of the dichroic mirror DM.

[0025] The second illumination optical system 32 corresponds to the illumination optical system of the present invention. The second illumination optical system 32 has an illumination optical axis OS tilted with respect to the optical axis OA, and performs oblique illumination (angled illumination) in which illumination light is irradiated onto the patient's eye E from an oblique direction without passing through the objective lens 20. By performing oblique illumination, stereoscopic imaging of a predetermined portion of the patient's eye E (such as the crystalline lens CL and the posterior capsule CLb) can be performed while avoiding the influence of ghosts due to reflections from the cornea of ​​the patient's eye E. Furthermore, because the second illumination optical system 32 performs oblique illumination onto the patient's eye E without passing through the objective lens 20, the illumination angle ω, which is the tilt angle of the illumination optical axis OS with respect to the optical axis OA, can be made larger than in the prior art (see Patent Document 1) in which oblique illumination is performed via the objective lens 20.

[0026] The second illumination optical system 32 includes a light source 32a and an illumination lens 32b. The light source 32a uses, for example, a bullet-shaped LED (Light Emitting Diode) and emits illumination light (white light) with a wavelength in the visible region and a color temperature of, for example, 4000 K to 6000 K. The illumination lens 32b transmits the illumination light from the light source 32a and irradiates the illumination light onto the patient's eye E without passing through the objective lens 20.

[0027] The position and orientation (illumination angle ω, illumination distance L and rotation angle position θ shown in Figs. 3 and 4 described later) of the second illumination optical system 32 are adjusted within a range that can improve the visibility of the posterior capsule CLb, as will be described in detail later. The second illumination optical system 32 is held by a holding unit (not shown) so that the above-mentioned position and orientation can be changed.

[0028] The observation optical system 40 has an observation optical axis OB parallel to the Y direction, and guides the return light from the patient's eye E, which has entered through the objective lens 20 and the dichroic mirror DM, to the imaging device 60. The observation optical system 40 includes an observation optical system 40L for the left eye and an observation optical system 40R for the right eye.

[0029] The left-eye observation optical system 40L includes a left-eye zoom expander 50L. The right-eye observation optical system 40R includes a right-eye zoom expander 50R. The left-eye zoom expander 50L includes multiple zoom lenses 51L, 52L, and 53L, and the right-eye zoom expander 50R includes multiple zoom lenses 51R, 52R, and 53R. Each of the zoom lenses 51L to 53L and each of the zoom lenses 51R to 53R can be moved in the direction of the observation optical axis OB by a magnification change mechanism (not shown).

[0030] The imaging device 60 captures an image of the return light from the patient's eye E, which is guided by the observation optical system 40. The imaging device 60 includes an imaging device 60L for the left eye and an imaging device 60R for the right eye.

[0031] The left-eye imaging device 60L includes an imaging lens 61L and an imaging element 62L. The imaging lens 61L forms an image of the returning light that has passed through the left-eye zoom expander 50L on the imaging surface of the imaging element 62L. The imaging element 62L is a two-dimensional area sensor. The imaging element 62L captures the returning light that has been imaged on its imaging surface and outputs an imaging signal.

[0032] The right-eye imaging device 60R includes an imaging lens 61R and an imaging element 62R. The imaging lens 61R forms an image of the returning light that has passed through the right-eye zoom expander 50R on the imaging surface of the imaging element 62R. The imaging element 62R is a two-dimensional area sensor. The imaging element 62R captures the returning light that has been imaged on its imaging surface and outputs an imaging signal.

[0033] Based on the imaging signals output from the left eye imaging device 60L and the right eye imaging device 60R, respectively, a control device (not shown) displays an observation image of the observed area of ​​the patient's eye E (e.g., the crystalline lens CL, the posterior capsule CLb) on a monitor (not shown).

[0034] It is also possible to provide a left eye eyepiece 64L instead of the left eye imaging device 60L, and a right eye eyepiece 64R instead of the right eye imaging device 60R. In this case, the surgeon observes the observation site of the patient's eye E through the left eye eyepiece 64L and the right eye eyepiece 64R. It is also possible to provide both the left eye imaging device 60L and the right eye imaging device 60R and the left eye eyepiece 64L and the right eye eyepiece 64R in the surgical microscope 10.

[0035] [Second illumination optical system 32] Fig. 3 is an explanatory diagram for explaining the illumination angle ω and illumination distance L of the second illumination optical system 32. Fig. 4 is an explanatory diagram for explaining the rotation angle position θ of the second illumination optical system 32. Fig. 5 is a diagram showing the Y-shaped suture Sb of the crystalline lens CL, which serves as an indicator of the visibility of the posterior capsule CLb.

[0036] 3 and 4 , the position and orientation of the second illumination optical system 32 is adjusted within a range that can improve the visibility of the posterior capsule CLb before and during cataract surgery on the patient's eye E. The position and orientation of the second illumination optical system 32 includes the illumination angle ω, illumination distance L, and rotation angle position θ of the second illumination optical system 32.

[0037] As described above, the illumination angle ω is the angle of the illumination optical axis OS with respect to the optical axis OA (see FIG. 3). The illumination distance L is the distance from the patient's eye E to the second illumination optical system 32 (e.g., the illumination lens 32b) in the direction along the illumination optical axis OS (see FIG. 3).

[0038] The rotational angle position θ is the angular position of the second illumination optical system 32 (illumination lens 32b, etc.) in the XY plane in the direction around the optical axis OA (see FIG. 4). Here, when the optical axis OA is viewed from above in the Z direction, the side opposite to the direction in which the surgeon is located is set to θ=0°, the side in which the surgeon is located is set to θ=180°, the right side of the surgeon (right hand direction) is set to θ=90°, and the left side of the surgeon (left hand direction) is set to θ=270°.

[0039] The ranges of the illumination angle ω, illumination distance L, and rotation angle position θ of the second illumination optical system 32 that can improve the visibility of the posterior capsule CLb will be specifically described below. In this embodiment, the Y-shaped suture of the crystalline lens is used as an indicator of the visibility of the posterior capsule CLb. As shown in Fig. 5, a Y-shaped suture Sa is formed on the anterior capsule CLa side of the crystalline lens CL, and a Y-shaped suture Sb is formed on the posterior capsule CLb side of the crystalline lens CL. The Y-shaped suture Sb serves as an indicator for the visibility of the posterior capsule CLb.

[0040] Fig. 6 is an explanatory diagram illustrating the relationship between the illumination angle ω and the visibility of the Y-shaped suture Sb. As shown in Fig. 6 and the previously described Fig. 3, the range of the illumination angle ω is set to 20°<ω<40°. Here, in the conventional technology (see Patent Document 1 above) in which oblique illumination is performed on the patient's eye E through an objective lens 20, the illumination angle ω only increases to approximately 5° to 6°, making the illumination angle ω small (deep). For this reason, in the conventional technology, the illumination light does not reach the scattering body of the posterior capsule CLb, making it difficult to see the Y-shaped suture Sb (posterior capsule CLb).

[0041] In contrast, the second illumination optical system 32 of the present embodiment performs oblique illumination on the patient's eye E without passing through the objective lens 20, so that the illumination angle ω can be made larger (shallower) than in the prior art. As a result, the illumination light reaches the scatterer of the posterior capsule CLb, improving the visibility of the Y-shaped suture Sb, that is, the visibility of the posterior capsule CLb. Here, if the illumination angle ω is made too large (too shallow), the entire posterior capsule CLb is illuminated by the illumination light, making it difficult to see a part of the posterior capsule CLb. When the illumination angle ω is about 30°, the visibility of the posterior capsule CLb is improved, but it is also necessary to consider the variation in the patient's eye E. Therefore, in the present embodiment, the range of the illumination angle ω is determined to be 20° < ω < 40° based on the results of experiments or simulations.

[0042] FIG. 7 is an explanatory diagram for explaining the relationship between the illumination distance L and the visibility of the Y-shaped suture Sb. As shown in FIG. 7 and the aforementioned FIG. 3, the range of the illumination distance L is determined to be 130 mm < L < 33 / mm. If the illumination distance L becomes too long, that is, if the second illumination optical system 32 moves too far away from the patient's eye E, the illumination light does not reach the posterior capsule CLb, making it difficult to visually recognize the Y-shaped suture Sb (posterior capsule CLb). Conversely, if the illumination distance L becomes too short, that is, if the second illumination optical system 32 approaches the patient's eye E too closely, flare appears in the observed image, making it difficult to visually recognize the Y-shaped suture Sb (posterior capsule CLb). Therefore, in the present embodiment, the range of the illumination distance L is determined to be 130 mm < L < 330 mm based on the results of experiments or simulations.

[0043] Note that based on the height-direction distance h (also referred to as the height position, see FIG. 3) from the patient's eye E to the second illumination optical system 32 (such as the illumination lens 32b) along the optical axis direction of the optical axis OA and the illumination angle ω, the illumination distance L can be calculated from the mathematical formula L = h / (cos ω). Therefore, instead of determining the range of the illumination distance L, the range of the height-direction distance h may be determined. In this case, for example, the height-direction distance h can be determined to be in the range of 150 mm to 250 mm.

[0044] Furthermore, when the distance from the optical axis OA along a direction perpendicular to the optical axis OA to the second illumination optical system 32 (illumination lens 32b, etc.) is defined as the vertical distance d (see FIG. 3), the illumination angle ω and the illumination distance L can be calculated based on the height distance h and the vertical distance d. Therefore, instead of determining the ranges of the illumination angle ω and the illumination distance L, the ranges of the height distance h and the vertical distance d may be determined.

[0045] 8 is an explanatory diagram illustrating the relationship between the rotation angle position θ and the visibility of the Y-stitch Sb. As shown in FIG. 8, by changing the rotation angle position θ of the second illumination optical system 32, the location where the illumination light is reflected in the scatterer of the posterior capsule CLb, i.e., the location that is easily visible in the scatterer, changes. Therefore, the optimal rotation angle position θ changes depending on which of the three suture lines that make up the Y-stitch Sb is being focused on. In this case, the rotation angle position θ is determined so that the illumination light is irradiated from a direction perpendicular to the extension direction of the suture line of interest.

[0046] Furthermore, if the rotation angle position θ of the second illumination optical system 32 is set in a certain angle range centered on the direction in which the surgeon is positioned, for example, 180°, it will interfere with the surgeon's cataract surgery. For this reason, the range of the rotation angle position θ of the second illumination optical system 32 is determined taking into consideration the visibility of the posterior capsule CLb and the position of the surgeon (including an assistant, the same applies hereinafter).

[0047] Fig. 9 is an explanatory diagram illustrating the range of rotational angle positions θ of the second illumination optical system 32 as viewed from above. Fig. 10 is an explanatory diagram illustrating a more preferable range of rotational angle positions θ of the second illumination optical system 32 as viewed from above. Note that the symbol T in Figs. 9 and 10 represents the trajectory traced by the second illumination optical system 32 when the rotational angle position θ of the second illumination optical system 32 is changed from 0° to 360°. Furthermore, the symbol PA in Figs. 9 and 10 represents the allowable range of the rotational angle position θ, and the symbol FA represents the forbidden range of the rotational angle position θ.

[0048] 9, as a result of experiments or simulations conducted in consideration of the visibility of the posterior capsule CLb and the position of the surgeon, the range of the rotational angle position θ of the second illumination optical system 32 is set to a range excluding the range of 120°≦θ≦240° (see prohibited range FA), i.e., within the range of −120° (240°)<θ<120° (see permitted range PA). Furthermore, as shown in FIG. 10, it is more preferable to set the range of the rotational angle position θ of the second illumination optical system 32 within at least one of the ranges of −30° (330°)<θ<30°, 60°<θ<120°, and 240°<θ<300°.

[0049] As described above, the surgical microscope 10 of this embodiment can significantly improve the visibility of the posterior capsule CLb compared to conventional methods by adjusting the illumination angle ω, illumination distance L, and rotation angle position θ of the second illumination optical system 32 to the optimum ranges described above. In particular, in this embodiment, the second illumination optical system 32 provides oblique illumination to the patient's eye E without passing through the objective lens 20, so that a larger illumination angle ω can be ensured compared to conventional methods, thereby improving the visibility of the posterior capsule CLb.

[0050] [Variations] Figure 11 is a diagram showing a modified example of the surgical microscope 10. Although the second illumination optical system 32 of the surgical microscope 10 in the above embodiment has a linear illumination optical axis OS, this illumination optical axis OS may be bent. As shown in Figure 11, the modified example of the surgical microscope 10 has basically the same configuration as the surgical microscope 10 in the above embodiment, except that it includes a second illumination optical system 36 instead of the second illumination optical system 32. Therefore, components that are identical in function or configuration to those in the above embodiment are designated by the same reference numerals, and their description will be omitted.

[0051] The illumination optical axis OS of the second illumination optical system 36 is bent in a direction perpendicular to the Z direction (up-down direction) and toward the optical axis OA (hereinafter referred to as the optical axis direction side) on the side opposite to the patient's eye E. The second illumination optical system 36 includes a light source 36a, a lens 36b, a filter 36c, and a reflecting mirror 36d, which are arranged along the side opposite to the optical axis direction side.

[0052] The light source 36a is, for example, a bullet-shaped LED similar to the light source 32a in the above embodiment, and emits the same illumination light as the light source 32a. The lens 36b is basically the same as the illumination lens 32b in the above embodiment, and transmits the illumination light incident from the light source 36a and emits it toward the filter 36c. The filter 36c adjusts the color of the illumination light.

[0053] The reflecting mirror 36d reflects the illumination light that has passed through the filter 36c and is incident thereon toward the patient's eye E without passing through the objective lens 20. This allows the second illumination optical system 36 to provide oblique illumination to the patient's eye E without passing through the objective lens 20.

[0054] The illumination angle ω of the second illumination optical system 36 is the angle of the illumination optical axis OS of the illumination light directed from the reflecting mirror 36d to the patient's eye E relative to the optical axis OA. The illumination distance L of the second illumination optical system 36 is the distance from the patient's eye E to the reflecting mirror 36d in the direction along the illumination optical axis OS. The rotational angle position θ of the second illumination optical system 36 is the angular position of the reflecting mirror 36d in the XY plane in the direction around the optical axis OA. The ranges of the illumination angle ω, illumination distance L, and rotational angle position θ are adjusted to the same ranges as in the above embodiment. This achieves the same effects as in the above embodiment. Furthermore, by bending the illumination optical axis OS in the second illumination optical system 36, the surgical microscope 10 can be made smaller.

[0055] In the modified example of the surgical microscope 10 shown in Figure 11, the illumination optical axis OS of the second illumination optical system 36 is bent in one direction in the Y direction, but as long as the surgical microscope 10 can be made smaller, the bending direction of the illumination optical axis OS is not particularly limited, and the illumination optical axis OS may be bent in any direction, such as the X direction or the Z direction.

[0056] [others] The configuration of the second illumination optical system 32, 36 constituting the surgical microscope 10 is not limited to the configurations shown in Figures 1 to 4 and 11 and can be modified as appropriate, as long as it is possible to provide oblique illumination of the patient's eye E without using the objective lens 20. Similarly, the configuration of the observation optical system 40 is not limited to the configuration shown in Figures 1 and 2 and can be modified as appropriate.

[0057] In the above embodiment, three parameters of the second illumination optical system 32 (similarly the second illumination optical system 36), namely, the illumination angle ω, the illumination distance L, and the rotation angle position θ, are adjusted, but it is also possible to adjust only one of the three parameters (for example, only the illumination angle ω, or only the illumination angle ω and the illumination distance L).

[0058] In the above embodiment, the optical axis OA of the objective lens 20 is parallel to the vertical direction, but the direction of this optical axis OA is not particularly limited, and it may be non-parallel to the vertical direction.

[0059] In the above embodiment, a surgical microscope 10 used to observe the posterior capsule CLb before and during cataract surgery was used as an example, but the present invention is applicable to various surgical microscopes 10 (excluding slit lamp microscopes) used to observe the posterior capsule CLb before and during various surgeries on a patient's eye E. [Explanation of symbols]

[0060] 10…Surgical microscope 20...Objective lens 31L, 31R…1st illumination optical system 32…Second illumination optical system 32a...Light source 32b...Lighting lens 36…Second illumination optical system 36a...Light source 36b...Lens 36c...filter 36d...Reflective mirror 40...Observation optical system 40L...Observation optical system for left eye 40R…Right eye observation optical system 50...Zoom Expander 50L...Zoom expander for left eye 50R...Zoom expander for right eye 51L~53L...Zoom lens 51R~53R...Zoom lens 60...imaging device 60L...Left-eye imaging device 60R…Right eye imaging device 61L, 61R...imaging lenses 62L, 62R...imaging element 64L, 64R...Right eyepiece CL…Crystalline lens CLa...anterior capsule CLb…Posterior capsule DM...Dichroic mirror E…Patient eye FA...Prohibited area L…Lighting distance OA…Optical axis OB: Observation optical axis OL, OR…optical axis OS: Lighting optical axis PA: Permitted range Sa, Sb…Y-shaped suture Y...Crystalline lens d…Vertical distance h: Height distance θ...Rotation angle position ω…Illumination angle

Claims

1. an illumination optical system that irradiates illumination light onto the patient's eye; an observation optical system that guides return light from the patient's eye illuminated with the illumination light through an objective lens to at least one of an imaging device and an eyepiece; Equipped with an illumination optical axis of the illumination optical system is inclined with respect to an optical axis of the objective lens, The illumination optical system irradiates the patient's eye with the illumination light without passing through the objective lens.

2. 2. The surgical microscope according to claim 1, wherein the optical axis of the objective lens is parallel to the vertical direction.

3. When a tilt angle of the illumination optical axis with respect to the optical axis of the objective lens is ω, the tilt angle is 20°<ω<40°, When an illumination distance, which is a distance from the patient's eye to the illumination optical system, is L, the illumination distance is 130 mm<L<330 mm, 3. The surgical microscope according to claim 2, wherein the rotation angle position of the illumination optical system in a direction around the optical axis of the objective lens is defined as θ, the direction opposite to the direction in which the surgeon is located when viewed from above in the up-down direction is defined as θ=0°, the direction in which the surgeon is located when viewed from above is defined as θ=180°, the right side of the surgeon when viewed from above is defined as θ=90°, and the left side of the surgeon when viewed from above is defined as θ=270°, and the rotation angle position is within a range excluding 120°≦θ≦240°.

4. 4. The surgical microscope according to claim 3, wherein the rotation angle position is within at least one of the ranges of −30°<θ<30°, 60°<θ<120°, and 240°<θ<300°.

5. 5. The surgical microscope according to claim 2, wherein the illumination optical axis is bent on a side opposite to the patient's eye.

6. 6. The surgical microscope according to claim 5, wherein the opposite side of the illumination optical axis is bent in a direction perpendicular to the up-down direction.

7. 5. The surgical microscope according to claim 1, which is used for observing the posterior capsule of the patient's eye during cataract surgery.

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