JP6856429B2 - Ophthalmic microscope - Google Patents

Description

The present invention relates to an ophthalmic microscope. More specifically, the present invention relates to an ophthalmic microscope suitable for binocular vision, in which residual aberration can be corrected and the afterimage aberration of an image observed by the left and right eyes is close to equal on the left and right. More specifically, the present invention relates to an ophthalmic microscope in which the objective lens can be made small in diameter and another optical system such as an OCT device can be easily installed.

In the field of ophthalmology, various ophthalmic microscopes are used for magnifying and observing the eye. Examples of such an ophthalmic microscope include a fundus camera, a slit lamp, a surgical microscope, and the like. These ophthalmic microscopes have a binocular optical system that provides binocular parallax that occurs between the left and right eyes for stereoscopic observation of the eye.

A typical conventional ophthalmic microscope is a Galilean stereomicroscope. The technical features of the Galilean stereomicroscope are that it is equipped with an objective lens that allows the optical axes of the left and right observation optical systems to pass through in common, and that the optical axes of the left and right observation optical systems are basically parallel. It is supposed to be. The Galilean stereomicroscope has the advantage that it can be easily combined with other optical systems and optical elements.
On the other hand, in the Galilean telescope, since the objective lens and the imaging optical system are eccentric, the residual aberrations are opposite to each other on the left and right, and it is difficult to reduce the residual aberrations.

The present inventors have previously developed an ophthalmic microscope that employs a Greenough stereomicroscope, which is a method different from the Galilean stereomicroscope (Patent Documents 1 and 2). The Greenough stereomicroscope is a microscope that has two independent observation optical systems on the left and right, and is arranged so that the optical axes of the left and right observation optical systems intersect. The Greenough stereomicroscope does not use a common objective lens, and each of the left and right observation optical systems is equipped with an objective lens.
According to the Greenough type physical microscopic boundary, it is possible to reduce the eccentricity of the objective lens and the coupling optical system, but there is a problem that the mechanism becomes complicated because the two independent observation optical systems are obliquely crossed. ..

By the way, as an inspection device that can be combined with an ophthalmic microscope, there is an OCT (Optical Coherence Tomography) device. The OCT device can be used for acquiring a cross-sectional image or a three-dimensional image of the eye, measuring the size of the eye tissue (net thickness, etc.), acquiring functional information of the eye (blood flow information, etc.), and the like.

Many devices have been developed in which an OCT device is incorporated into an ophthalmic microscope, and most of them are those in which the optical path of the OCT optical system is transmitted through an objective lens of the Galilean type body microscope (Patent Documents 3 to 7). ..
Further, a method has been developed in which the optical path of the OCT optical system does not pass through the Galilean-type objective lens of the real microscopic boundary (Patent Document 8), but the OCT optical system is provided between the objective lens and the eye to be inspected.

When observing with an ophthalmic microscope, there is a method of using a front lens to switch between observing the anterior segment of the cornea and iris and observing the posterior segment of the retina. In this method, the posterior eye portion such as the retina can be observed by inserting the anterior lens in the optical path between the eye to be inspected and the objective lens, and the cornea and the cornea can be removed by detaching the anterior lens from the optical path. It is possible to observe the anterior segment of the eye such as the iris (Patent Document 9).

Japanese Unexamined Patent Publication No. 2016-185177 Japanese Unexamined Patent Publication No. 2016-185178 Japanese Unexamined Patent Publication No. 8-66421 Japanese Unexamined Patent Publication No. 2008-264488 Japanese Unexamined Patent Publication No. 2008-268852 Special Table 2010-522055 Japanese Unexamined Patent Publication No. 2008-264490 U.S. Pat. No. 8,366,271 Japanese Unexamined Patent Publication No. 2003-062003

The Galileo stereomicroscope used in the conventional ophthalmic microscope system has the optical axis (O400L) of the observation optical system for the left eye and the observation optical system for the right eye, as schematically shown in FIG. 13 (A). An objective lens (401) through which the optical axis (O400R) is commonly transmitted is provided. The observation optical system for the left and right eyes includes, for example, a variable magnification lens (402), an eyepiece lens (408), and the like. However, as schematically shown in FIG. 13B, the optical axis (A402) of the variable magnification lens and the optical axis (A401) of the objective lens are eccentric by about 10 to 15 mm. Therefore, it is difficult to correct the residual aberration that occurs in the left and right eyes. Further, since the residual aberration occurs on the outer peripheral side of the objective lens (401), as shown schematically in FIG. 13C, when the subject (2) is observed with both eyes, chromatic aberration of magnification and coma are generated. There is a problem that the image for the left eye (V400L) and the image for the right eye (V400R) are generated on opposite sides, and different images must be observed by the left and right eyes. There are two types of Galilean stereomicroscopes, one with a convergence angle of 0 ° and the other with a convergence angle of not 0 °. In either type, it is difficult to reduce the residual aberration by correction. It was.

Further, the Galilean stereomicroscope has a demerit that the degree of freedom in optical design and mechanical design is limited because it is necessary to use a large-diameter objective lens.
For example, as shown in Patent Documents 3 to 7, an ophthalmologic microscope in which an OCT optical system is incorporated in a Galilean telescope has a method in which the optical path of the OCT optical system passes through an objective lens of the Galilean telescope. Therefore, the OCT optical system and the observation optical system could not be made independent.
As shown in Patent Document 8, as a method in which the optical path of the OCT optical system does not pass through the Galilean-type objective lens of the physical microscope, there is a method in which the OCT optical system is provided under the objective lens. There was a problem that it was not possible to secure a sufficient working space between them.

On the other hand, in the Greenough stereomicroscope, as shown in FIG. 14 (A), the optical axis (O400L) of the observation optical system for the left eye and the optical axis (O400R) of the observation optical system for the right eye are obliquely crossed. , An objective lens through which these optical axes are commonly transmitted is not provided, and each optical system has an objective lens (401). As shown in FIG. 14B, the optical axis (A402) of the variable magnification lens and the optical axis (A401) of the objective lens are not eccentric, residual aberration can be corrected, and they occur in the left and right eyes. There is no technical problem that chromatic aberration of magnification and coma are generated on the opposite sides of the left and right eyes. Further, since the Greenough type physical microscope does not use a large-diameter objective lens, an OCT optical system can be independently provided between the left and right observation optical systems.
However, in the Greenough type physical microscopic boundary, as shown in FIG. 14 (A), the focus position (Q400L) of the observation optical system for the left eye does not overlap with the focus position (Q400R) of the observation optical system for the right eye. As shown in FIG. 14C, there is a problem that the focus difference in the periphery is reversed in the image of the left and right eyes.
In addition, since the Greenough stereomicroscope diagonally intersects two independent observation optical systems, it has to be mechanically complicated, and there is an inconvenience that it is difficult to assemble the variable magnification optical system. It was.

Therefore, an object of the present invention is to solve the technical problems of the conventional ophthalmic microscope, to correct the residual aberration, and to make the residual aberration almost even on the left and right sides for binocular vision. To provide a suitable ophthalmic microscope. Another object of the present invention is to provide an ophthalmic microscope in which an objective lens can have a small aperture and another optical system such as an OCT device can be easily installed.

As a result of diligent studies, the present inventors have eliminated the large-diameter objective lens through which the left and right observation optical systems commonly transmit, and provided objective lenses in each of the left and right observation optical systems, thereby eccentricity of the lens. It has been found that the problem can be solved, the residual aberration can be corrected, and the objective lens can be made smaller in diameter so that another optical system can be easily installed. Further, the present inventors make the left and right observation optical systems by forming the objective lens as a lens group having at least a first lens, an optical element for changing the direction of the optical axis, and a second lens. It has been found that the optical axes can be crossed by the objective lens without oblique crossing. Here, when the anterior lens is used to switch between the observation of the anterior segment and the observation of the posterior segment, the OCT scanning surface position and the observation focal plane position are determined according to the focal length (power) of the anterior lens. Also, the optical path length of the measurement light of the OCT optical system changes due to the insertion and removal of the front lens, and the difference between the optical path length of the measurement light and the optical path length of the reference light changes. By changing 1) the distance between the objective lens and the front lens, 2) the distance between the objective lens for OCT and the front lens, and 3) the length of the optical path of the reference light of the OCT optical system. We have found that it can be adjusted, and have completed the present invention. Specifically, the present invention comprises the following technical matters.

(1) The present invention includes an illumination optical system for illuminating the eye to be inspected, an observation optical system for the left eye for observing the eye to be inspected illuminated by the illumination optical system, and an observation optical system for the right eye. A system, an OCT optical system having an optical path of measurement light and an optical path of reference light for inspecting the eye to be inspected by optical coherence stromography, and an OCT optical system which can be inserted into and removed from the optical path between the eye to be examined and the objective lens. In an ophthalmic microscope equipped with a stationary lens
In the ophthalmic microscope, the optical axis of the observation optical system for the left eye and the optical axis of the observation optical system for the right eye are substantially parallel.
The left-eye observation optical system and the right-eye observation optical system each have an objective lens, and the objective lens includes a first lens, an optical element that changes the direction of the optical axis, and a second. Consists of a lens group having at least a lens
The objective lens changes the direction of the optical axis of the left eye observation optical system and the direction of the optical axis of the right eye observation optical system so as to intersect each other on the side of the eye to be inspected.
The OCT optical system is arranged in the region between the left eye observation optical system and the right eye observation optical system, and the OCT objective lens through which the optical axis of the OCT optical system is transmitted is separate from the objective lens. Have and
When the front lens is inserted into the optical path between the eye to be inspected and the objective lens, the optical axis of the observation optical system and the optical axis of the OCT optical system pass through the front lens.
The distance of the following 1) or 2) automatically changes according to the focal length of the front lens inserted in the optical path between the eye to be inspected and the objective lens.
1) Distance between the objective lens and the front lens 2) Distance between the OCT objective lens and the front lens The front lens is inserted and removed on the optical path between the eye to be inspected and the objective lens. The present invention relates to an ophthalmic microscope, characterized in that the length of the optical path of the reference light of the OCT optical system is automatically changed according to the focal length of the front lens.
(2) In the ophthalmic microscope of the present invention, a lens discrimination mechanism for acquiring information on the focal length of the front lens inserted in the optical path between the eye to be inspected and the objective lens, and a lens discrimination mechanism.
A position adjusting mechanism for adjusting the distance between the objective lens and the front lens and / or the distance between the OCT objective lens and the front lens.
It is preferable to further have a control mechanism for controlling the position adjustment mechanism based on the information regarding the focal length of the front lens acquired by the lens discrimination mechanism.
(3) In any of the ophthalmic microscopes, it is preferable that the optical element for changing the direction of the optical axis is a wedge prism.
(4) In any of the ophthalmic microscopes, it is preferable that the first lens is a concave lens having a negative power and the second lens is a convex lens having a positive power.
(5) In any of the ophthalmic mirror microscopes, the first lens, the optical element for changing the direction of the optical axis, and the second lens are arranged in this order from the side of the eye to be inspected. If so,
The optical axis of the first lens of the left eye observation optical system and the optical axis of the first lens of the right eye observation optical system are inclined in a direction in which they intersect each other on the side of the eye to be inspected. It is preferable to have.
(6) In any of the ophthalmic microscopes, the first lens, the optical element for changing the direction of the optical axis, and the second lens are arranged in this order from the side of the eye to be inspected. If so,
The optical axis of the second lens of the left eye observation optical system and the optical axis of the second lens of the right eye observation optical system are inclined in a direction away from each other on the side of the eye to be inspected. Is preferable.

According to the present invention, there is provided an ophthalmic microscope suitable for binocular vision, which enables correction of residual aberration and has residual aberration that is almost even on the left and right. Further, according to the present invention, there is provided an ophthalmic microscope in which an objective lens, which is an optical component constituting an ophthalmic microscope, can have a small diameter, and another optical system such as an OCT device can be easily installed. Will be done. Further, according to the present invention, it is possible to reduce the troublesome time and effort of optical adjustment when inserting and removing the front lens.

It is a front view which shows typically the structure of the optical system of the ophthalmic microscope of 1st Embodiment of this invention. It is a side view which shows typically the structure of the optical system of the ophthalmic microscope of 1st Embodiment of this invention. It is a drawing which shows typically the optical composition of the OCT unit used in the ophthalmic microscope of the 1st Embodiment of this invention. It is sectional drawing which shows typically the arrangement of the optical path around the objective lens in the ophthalmic microscope of 1st Embodiment of this invention. It is a front view which shows typically the optical composition of the objective lens in the ophthalmic microscope of 1st Embodiment of this invention. FIG. 5 (A) shows the configuration of the objective lens used in the ophthalmic microscope of the first embodiment, and FIG. 5 (B) shows the direction of the optical axis of each lens constituting the objective lens. It is a drawing which shows typically the case where the front lens is inserted in the optical path between the eye under test and the objective lens in the ophthalmic microscope of the 1st Embodiment of this invention. FIG. 6 (A) shows a case where a lens having a power (refractive power) of D is inserted into the optical path as a front lens, and FIG. 6 (B) shows a power (refractive power) of D'greater than D. The case where the front lens having is inserted in the optical path is shown. It is a drawing which shows typically the ophthalmic microscope of 1st Embodiment of this invention, and the positioning apparatus which holds it. It is a drawing which shows typically the peripheral part of the front lens position adjustment mechanism of the ophthalmic microscope of 1st Embodiment of this invention. In the ophthalmic microscope of the first embodiment of the present invention, the difference in optical path length between the case where the pre-lens is inserted in the optical path between the objective lens and the eye to be inspected and the case where the pre-lens is detached is exemplified. It is a drawing which shows. FIG. 9A shows a case where the anterior segment such as the cornea and the iris is observed without inserting the anterior lens between the objective lens and the eye to be inspected, and FIG. 9B shows the objective lens and the subject. The case where the anterior lens is inserted during the optometry to observe the posterior segment of the eye such as the retina of the fundus is shown. It is sectional drawing which shows typically the arrangement of the optical path around the objective lens in the ophthalmic microscope of the 2nd Embodiment of this invention, and the ophthalmic microscope of 3rd Embodiment. FIG. 10 (A) shows the arrangement of the optical path around the objective lens of the ophthalmic microscope of the second embodiment, and FIG. 10 (B) shows the optical path around the objective lens of the ophthalmic microscope of the third embodiment. Indicates the arrangement of. It is a front view which shows typically the optical composition of the objective lens in the ophthalmic microscope of the 4th Embodiment of this invention. FIG. 11A shows the configuration of the objective lens used in the ophthalmic microscope of the fourth embodiment, and FIG. 11B shows the direction of the optical axis of each lens constituting the objective lens. It is a front view which shows typically the optical composition of the objective lens in the ophthalmic microscope of the 5th Embodiment of the ophthalmic microscope of this invention. FIG. 12 (A) shows the configuration of the objective lens used in the ophthalmic microscope of the fifth embodiment, and FIG. 12 (B) shows the direction of the optical axis of each lens constituting the objective lens. It is a schematic diagram which showed the image observed with the left and right eyes by the Galilean type stereomicroscope which is a prior art, and the stereomicroscope. FIG. 13 (A) is a schematic view showing the configuration of the optical system of the observation optical system for the left and right eyes of the Galilean telescope, and FIG. 13 (B) is the light of each lens of the Galilean telescope. It is a schematic diagram which shows the axis, and FIG. 13C is a schematic diagram which shows the image observed by the left and right eyes. It is a schematic diagram which showed the image observed with the left and right eyes by the Grinault type stereomicroscope which is a prior art, and the stereomicroscope. FIG. 14 (A) is a schematic view showing the configuration of the optical system of the observation optical system for the left and right eyes of the Greenough type physical microscopic boundary, and FIG. 14B is the light of each lens of the Greenough type physical microscopic boundary. It is a schematic diagram which shows the axis, and FIG. 14C is a schematic diagram which shows the elephant observed by the left and right eyes.

1. 1. Outline of the Ophthalmic Microscope of the Present Invention The ophthalmic microscope of the present invention includes an illumination optical system for illuminating the eye to be inspected, an observation optical system for the left eye and an observation optical system for the right eye for observing the eye to be inspected illuminated by the illumination optical system. An observation optical system having an observation optical system, an OCT optical system having an optical path of measurement light and an optical path of reference light for inspecting the eye to be inspected by optical coherence stromography, and light between the eye to be inspected and the objective lens. It relates to an ophthalmic microscope equipped with a removable front lens on the road.
Since the ophthalmic microscope of the present invention has objective lenses with smaller diameters in the left eye observation optical system and the right eye observation optical system, respectively, the left eye observation optical system and the right eye observation optical system It is not necessary to use a large-diameter objective lens that transmits light in common. Therefore, the eccentricity between the optical axis of the objective lens and the optical axis of the lens in front of the objective lens becomes small, and the residual aberration can be corrected. Further, in the ophthalmic microscope of the present invention, it is not necessary to use an objective lens having a large diameter, and the objective lens can be made smaller in diameter, so that another optical system such as an OCT optical system can be easily installed.
The ophthalmic microscope of the present invention uses a lens group having at least a first lens, an optical element for changing the direction of the optical axis, and a second lens as an objective lens. With such an objective lens, the directions of the optical axis of the observation optical system for the left eye and the optical axis of the observation optical system for the right eye are changed so as to intersect each other on the side of the eye to be inspected. Therefore, in the ophthalmic microscope of the present invention, the optical axis of the observation optical system for the left eye and the optical axis of the observation optical system for the right eye are substantially parallel to each other in the ophthalmic microscope, and the optical axis is closer to the eye to be inspected than the objective lens. The two optical axes can be crossed, and there is no need for a complicated mechanism in which the left and right observation optical systems are arranged obliquely as in the case of a Greenough stereomicroscope.

In the present invention, the "ophthalmic microscope" refers to a medical or examination device capable of magnifying and observing an eye to be inspected, including not only for humans but also for animals. The “ophthalmic microscope” includes, but is not limited to, a fundus camera, a slit lamp, a microscope for ophthalmic surgery, and the like.
The ophthalmic microscope of the present invention is used for observing (imaging) a magnified image of an eye to be inspected in medical treatment or surgery in the field of ophthalmology. The observation target site may be any site of the patient's eye, for example, the anterior segment may be the cornea, the corner, the vitreous body, the crystalline lens, the ciliary body, or the like, and the posterior segment may be the retina or choroid. Or a vitreous body. Further, the observation target portion may be a peripheral portion of the eye such as an eyelid or an orbit.

The ophthalmic microscope of the present invention has a function as a microscope for magnifying and observing the eye to be inspected, an OCT optical system for inspecting the eye to be inspected by optical coherence tomography, and a function as another ophthalmic apparatus. Can have. Examples of functions as other ophthalmic devices include laser treatment, axial length measurement, refractive power measurement, and higher-order aberration measurement. The function as another ophthalmic apparatus includes an arbitrary configuration capable of performing an examination, measurement, and imaging of the eye to be inspected by an optical method.
The ophthalmic microscope of the present invention can include a control unit for controlling the position and inclination of each lens, a light source, and a display unit for displaying an captured image. Further, these control units and display units may be separate from the ophthalmic microscope.

In the present invention, the "illumination optical system" includes an optical element for illuminating the eye to be inspected. The illumination optical system may further include a light source, but may be one that guides natural light to the eye to be inspected.

In the present invention, the "observation optical system" includes an optical element that enables the eye to be inspected to be observed by the return light reflected and scattered by the eye to be inspected illuminated by the illumination optical system. Is. In the present invention, the observation optical system includes an observation optical system for the left eye and an observation optical system for the right eye, and when parallax is generated in the images obtained by the left and right observation optical systems, binocular vision is used. It is also possible to observe three-dimensionally.
Further, the "observation optical system" of the present invention may be one in which the eye to be inspected can be observed by the naked eye of the observer through an eyepiece, an eyepiece, or the like, and can be observed by receiving light from an image pickup element or the like and imaging it. It may be capable, or it may have both functions.

In the present invention, the "OCT optical system" includes an optical element that allows OCT measurement light and reference light to pass through. The OCT optical system can further include an OCT light source.
In the present invention, the optical elements used in the "illumination optical system", the "observation optical system", and the "OCT optical system" are not limited to these, but are, for example, a lens, a prism, a mirror, and an optical filter. , Aperture, diffraction grating, polarizing element and the like can be used.

In the present invention, the optical axis of the observation optical system for the left eye and the optical axis of the observation optical system for the right eye are "substantially parallel" in the ophthalmic microscope. It means that the main paths in the microscope are almost parallel, and a part of the optical axis may be non-parallel, and the main paths should be parallel in the range of 5 ° or less. Just do it. However, in order to facilitate the arrangement of the lenses of the optical system, it is preferable to make them parallel as close to 0 ° as possible, and it is preferable to make them parallel in a range of 3 ° or less.

In the present invention, the "objective lens" refers to a lens or a lens group provided on the side of the eye to be inspected in an ophthalmic microscope. For example, when the objective lens is composed of three lens groups, the third lens from the side of the eye to be inspected is the objective lens. When the objective lens is composed of four lens groups, the fourth lens from the side of the eye to be inspected is the objective lens. However, the front lens (loupe) that is temporarily inserted between the objective lens and the eye to be inspected is not included in the "objective lens" in the present invention.

In the present invention, the "optical element that changes the direction of the optical axis" may be any optical element that can change the direction of the optical path, and is not limited to these, but the optical path is changed by refraction / reflection. A wedge prism, a longoid type prism capable of changing the position and orientation of the optical axis, and the like can be used.

In the ophthalmic microscope of the present invention, the OCT optical system is arranged in the region between the observation optical system for the left eye and the observation optical system for the right eye, and the optical axis of the OCT optical system is separated from the objective lens of the observation optical system. It has an OCT objective lens through which the light is transmitted.
Then, when the front lens is inserted in the optical path between the eye to be inspected and the objective lens, the optical axis of the observation optical system and the optical axis of the OCT optical system pass through the front lens. The OCT scanning surface position and the observation focal surface position change according to the focal length (power).
However, in the ophthalmic microscope of the present invention, the following distances 1) or 2) are automatically changed according to the focal length of the front lens inserted in the optical path between the eye to be inspected and the objective lens. ..
1) Distance between the objective lens and the front lens 2) Distance between the OCT objective lens and the front lens Therefore, in the ophthalmic microscope of the present invention, the OCT scanning surface position and the observation focal surface position are used as observation targets. It is possible to reduce the troublesome manual adjustment for matching.

Here, in order to change the distance between the objective lens and the front lens, it is sufficient to move both or either of the objective lens and the front lens with respect to the main body of the ophthalmic microscope, and for OCT. In order to move the distance between the objective lens and the front lens, the OCT objective lens and / or the front lens may be moved with respect to the main body of the ophthalmologic microscope. Preferably, by moving the front lens with respect to the microscope body, both the distance to the objective lens and the distance to the OCT objective lens can be changed.

Further, in the ophthalmic microscope of the present invention, when the front lens is inserted and removed on the optical path between the eye to be inspected and the objective lens, the optical path length of the measurement light of the OCT optical system changes, and the optical path of the measurement light is changed. The difference between the length and the optical path length of the reference light changes, and it is not possible to interfere correctly.
However, in the ophthalmic microscope of the present invention, when the front lens is inserted and removed on the optical path between the eye to be inspected and the objective lens, the optical path of the reference light of the OCT optical system depends on the focal length of the front lens. The length of the lens changes automatically.
Therefore, the ophthalmic microscope of the present invention can correctly obtain a tomographic image by OCT.

Here, "the front lens is inserted / removed" means that one type of front lens is inserted into the optical path between the eye to be inspected and the objective lens, and the front lens is not only detached but also placed on the optical path. Includes the replacement of the lens with another type of pre-lens.
Optical elements can be used to change the length of the optical path of the reference light of the OCT optical system, for example, but not limited to, moving the mirror at the turning point of the optical path of the reference light. The optical path length can be changed by allowing the light path length to be changed, and the optical path length can be changed by inserting and removing the optical path length correction member on the optical path of the reference light and changing the optical path length depending on the difference in the refractive index between the member and the atmosphere.

In the present invention, "the OCT optical system is arranged in the region between the observation optical system for the left eye and the observation optical system for the right eye" means that the observation optical system for the left eye is viewed from one direction. It means that the OCT optical system exists between the observation optical systems for the right eye.
In the present invention, "automatically changing" means the distance of 1) or 2) described above or the length of the optical path of the reference light of the OCT optical system by a mechanical and / or electrical mechanism, not manually. Means that changes.

2. First Embodiment Hereinafter, an example of the embodiment of the present invention will be described in detail with reference to the drawings.
1 to 9 are drawings schematically showing a first embodiment which is an example of an ophthalmic microscope of the present invention. Of these drawings, FIG. 1 is a front view schematically showing the configuration of the optical system of the ophthalmic microscope of the first embodiment, and FIG. 2 is a side view of the configuration of the optical system. Further, FIG. 3 is a drawing schematically showing the optical configuration of the OCT unit, and FIG. 4 is a cross-sectional view schematically showing the arrangement of the optical path around the objective lens.

As shown in the front view of FIG. 1, the optical system of the ophthalmic microscope (1) is an observation optical system consisting of an observation optical system (400L) for the left eye and an observation optical system (400R) for the right eye of the observer. It has a system and an OCT optical system (500).
Further, as shown in the side view of FIG. 2, the optical system of the ophthalmic microscope (1) further includes an illumination optical system (300). The observation optical system (400) is used for magnifying and observing the eye to be inspected (8) illuminated by the illumination optical system (300).
As shown in FIGS. 1 and 2, the observation optical system (400), the OCT optical system (500), and the illumination optical system (300) are housed in the ophthalmic microscope main body (6) shown by the alternate long and short dash line. ing.

In FIG. 1, the optical axis of the observation optical system (400L) for the left eye is shown by a dotted line (O-400L), and the optical axis of the observation optical system (400R) for the right eye is shown by a dotted line (O-400R). The optical axis of the OCT optical system is indicated by a dotted line (O-500).

As shown in FIG. 1, the optical axis (O-400L) of the observation optical system for the left eye and the optical axis (O-400R) of the observation optical system for the right eye are arranged in the ophthalmic microscope main body (6). It is parallel.
Therefore, the ophthalmic microscope (1) of the first embodiment does not need to have a complicated mechanism in which the left and right observation optical systems are arranged so as to intersect each other as in the Greenough stereomicroscope.

As shown in FIG. 1, the left and right observation optical systems (400L, 400R) each have an objective lens (401). The objective lens (401) is an objective lens composed of a lens group, and includes a first lens (401a), an optical element (401b) that changes the direction of the optical axis, and a second lens (401c). ing.
In the first embodiment, a wedge prism is used as the optical element (401b) for changing the direction of the optical axis, and the base direction is inside (base-in). The wedge prisms change the directions of the optical axes (O-400L, O-400R) of the left and right observation optical systems so that they intersect each other on the side of the eye to be inspected.

In the first embodiment, the first lens (401a) is a concave lens having a negative power. The optical axes of the left and right first lenses are inclined inward (directions in which they intersect each other on the side of the eye to be inspected).
The second lens (401c) is a convex lens having a positive power.

The objective lens (401) used in the ophthalmic microscope of the first embodiment has a single large-diameter lens through which the optical axes of the left and right observation optical systems are commonly transmitted, as in the conventional Galilean telescope. It is not a lens, but an objective lens that the left and right observation optical systems have independently. Therefore, as shown in FIG. 1, the objective lens (401) can have a small aperture, and the OCT optical system (500) can be easily installed between the left and right observation optical systems (400L, 400R). Can be done.
Further, as shown in FIG. 1, the left and right objective lenses (401) are oriented so as to intersect the optical axes (O-400L, O-400R) of the left and right observation optical systems on the side of the eye to be inspected. Therefore, it is possible to observe the same part of the eye to be inspected with both eyes with the left and right eyes.

Hereinafter, the ophthalmic microscope of the first embodiment will be described in more detail.
As shown in FIG. 2, the illumination optical system (300) illuminates the eye to be inspected (8), and includes an illumination light source (9), an optical fiber (301), an outlet diaphragm (302), and a condenser lens ( 303), an illumination field diaphragm (304), a collimating lens (305), and a reflection mirror (306). The optical axis of these illumination optical systems (300) is shown by a dotted line (O-300) in FIG.

The illumination light source (9) is provided outside the main body of the ophthalmic microscope (6). One end of the optical fiber (301) is connected to the illumination light source (9). The other end of the optical fiber is arranged at a position facing the condenser lens (303) inside the main body of the ophthalmic microscope (6). The illumination light output from the illumination light source (9) is guided by the optical fiber (301) and incident on the condenser lens (303).
An exit aperture diaphragm (302) is provided at a position facing the exit port (fiber end on the condenser lens (303) side) of the optical fiber (301). The exit aperture diaphragm (302) acts to block a part of the exit port of the optical fiber (301). When the blocking area by the emission port diaphragm (302) is changed, the emission area of the illumination light is changed. Thereby, the irradiation angle by the illumination light, that is, the angle formed by the incident direction of the illumination light with respect to the eye to be inspected (8) and the optical axis of the objective lens (401) can be changed.

The illumination field diaphragm (304) is provided at a position (x position) optically conjugate with the front focal position (U0) of the objective lens (401). The collimating lens (305) converts the illumination light that has passed through the illumination field diaphragm (304) into a parallel luminous flux. The reflection mirror (306) reflects the illumination light converted into a parallel luminous flux by the collimating lens (305) toward the objective lens (401). The reflected light is applied to the eye to be inspected (8).
The illumination light (a part of) irradiated to the eye to be inspected (8) is reflected and scattered by the tissue of the eye to be inspected such as the cornea and the retina. The reflected / scattered return light (also referred to as “observation light”) is incident on the observation optical system (400).

As shown in FIG. 1, the left and right observation optical systems (400L, 400R) are an objective lens (401), a variable magnification lens (402), a beam splitter (403), an imaging lens (404), and an image correction lens, respectively. It includes a vertical prism (405), an eye width adjusting prism (406), a field diaphragm (407), and an eyepiece lens (408). The beam splitter (403) has only an observation optical system (400R) for the right eye.
The variable magnification lens (402) is a lens group including a plurality of zoom lenses (402a, 402b, 402c). Each zoom lens (402a, 402b, 402c) can be moved along the optical axes (O-400L, O-400R) of the left and right observation optical systems by a scaling mechanism (not shown). As a result, the magnifying magnification when observing or photographing the eye to be inspected (8) is changed.

As shown in FIG. 1, the beam splitter (403) of the observation optical system (400R) for the right eye transfers a part of the observation light guided from the eye to be inspected (8) along the observation optical path for the right eye. Separate and lead to the imaging optical system. The photographing optical system includes an imaging lens (1101) and a television camera (1102).
The television camera (1102) includes an image sensor (1102a). The image sensor (1102a) is composed of, for example, a CCD (Charge Coupled Devices) image sensor, a CMOS (Complementary Metal Oxide Semiconductor) image sensor, or the like. As the image pickup device (1102a), one having a two-dimensional light receiving surface (area sensor) is used.
When using the ophthalmic microscope (1), the light receiving surface of the image sensor (1102a) is arranged at a position optically conjugate with, for example, the surface of the cornea or retina of the eye to be inspected (8).

The image erecting prism (405) converts the inverted image into an erect image. The eye width adjusting prism (406) is an optical element for adjusting the distance between the left and right observation optical paths according to the eye width (distance between the left eye and the right eye) of the observer. The visual field diaphragm (407) limits the observer's visual field by blocking the peripheral region in the cross section of the observation light. The field diaphragm (407) is provided at a position (X position) conjugate with the front focal position (U0) of the objective lens (401).
The observation optical system (400L, 400R) may be configured to include a stereo variator configured to be removable from the optical path of the observation optical system. The stereo variator is an optical axis position changing element for changing the relative positions of the optical axes (O-400L, O-400R) of the left and right observation optical systems guided by the left and right variable magnification lens systems (402), respectively. is there. The stereo variator is retracted to, for example, a retracted position provided on the observer side with respect to the optical path of the observation optical system.

As shown in FIG. 1, when observing the posterior segment of the fundus such as the retina, the anterior lens (14) uses a moving means (not shown) to move the optical axes O-400L and O-400R in front of the eye to be inspected. It is inserted on the O-500. In this case, the anterior focal position (U0) of the objective lens (401) is conjugate with the retina of the fundus.
When observing the anterior segment of the cornea, iris, etc., the anterior lens is detached from the front of the eye to be inspected for observation.

As shown in FIG. 1, the OCT optical system (500) includes an OCT unit (10), an optical fiber (501), a collimating lens (502), an illumination field diaphragm (503), scanners (504a, 504b), and relay optics. The system (505), the first lens group (506), the second lens group (507), the reflection mirror (508), and the objective lens for OCT (509) are included.

The OCT unit (10) divides the light from the OCT light source having low coherence (short coherence distance) into the measurement light and the reference light. The measurement light is guided by the OCT optical system (500) and irradiated to the eye to be inspected (8), is reflected and scattered in the tissue of the eye to be inspected, and is guided to the OCT unit (10) as return light. The OCT unit (10) detects the interference between the return light of the measurement light and the reference light. This makes it possible to obtain a tomographic image of the tissue of the eye to be inspected.

As shown in FIG. 1, the OCT unit (10) is provided outside the ophthalmic microscope main body (6), but one end of the optical fiber (501) is connected to the ophthalmic microscope main body. It is connected to (6). The measurement light generated by the OCT unit (10) is emitted from the other end of the optical fiber (501). The emitted measurement light is a collimating lens (502), an illumination field aperture (503), a scanner (504a, 504b), a relay optical system (505), a first lens group (506), a second lens group (507), and reflection. The return light of the measurement light that is irradiated to the test eye (8) via the mirror (508) and the OCT objective lens (509) and is reflected and scattered by the tissue of the test eye (8) reverses the same path. It travels and enters the other end of the optical fiber (501).

As shown in FIG. 1, the collimating lens (502) converts the measurement light emitted from the other end of the optical fiber (501) into a parallel luminous flux. The collimating lens (502) and the other end of the optical fiber (501) are configured to be relatively movable along the optical axis of the measurement light. In the first embodiment, the collimating lens (502) is configured to be movable, but the other end of the optical fiber (501) may be configured to be movable along the optical axis of the measurement light.
The illumination field diaphragm (503) is conjugate with the front focal position (U0) of the objective lens (401).

The scanners (504a, 504b) in the OCT optical system two-dimensionally change the direction of the measurement light as a parallel luminous flux by the collimating lens (502). For the scanner (504a, 504b), a reflective member configured to be rotatable around each of the two axes intersecting each other is used. Examples of the reflective member include a galvano mirror, a polygon mirror, a rotating mirror, a MEMS (Micro Electro Mechanical Systems) mirror, and the like. In the first embodiment, the scanners (504a, 504b) are configured to include a galvano mirror. That is, the scanners are a first scanner (504a) having a reflective surface that can rotate around the first axis, and a second scanner that has a reflective surface that can rotate around the second axis that is orthogonal to the first axis. (504b) is included. A relay optical system (505) is provided between the first scanner (504a) and the second scanner (504b).
The first lens group (506) is configured to include one or more lenses, and the second lens group (507) is also configured to include one or more lenses.
The OCT objective lens (509) may have an optically conjugate relationship with a member such as a galvanometer mirror, in which case the aperture of the OCT objective lens (509) can be reduced.
Visible light for observation can also be added to the scanner in the OCT optical system.

FIG. 3 is a drawing schematically showing an optical configuration of an OCT unit (10) used in the ophthalmic microscope of the first embodiment.
As shown in FIG. 3, the OCT unit (10) divides the light emitted from the OCT light source unit (1001) into a measurement light (LS) and a reference light (LR), and the measurement light (LR) passing through another optical path. It constitutes an interferometer that detects the interference between the LS) and the reference light (LR).
The OCT light source unit (1001) is configured to include a wavelength scanning type (wavelength sweep type) light source capable of scanning (sweeping) the wavelength of emitted light, similar to a general swept source type OCT device. The OCT light source unit (1001) changes the output wavelength with time at a near-infrared wavelength that is invisible to the human eye. The light output from the OCT light source unit (1001) is indicated by reference numeral L0.

The light L0 output from the OCT light source unit (1001) is guided by the optical fiber (1002) to the polarization controller (1003), and its polarization state is adjusted. The polarization controller (1003) adjusts the polarization state of the light L0 guided in the optical fiber (1002) by, for example, applying stress from the outside to the looped optical fiber (1002).
The light L0 whose polarization state is adjusted by the polarization controller (1003) is guided by the optical fiber (1004) to the fiber coupler (1005) and divided into the measurement light (LS) and the reference light (LR).

As shown in FIG. 3, the reference light (LR) is guided by the optical fiber (1006) to the collimator (1007) to become a parallel luminous flux. The reference light LR that has become a parallel luminous flux is guided to the corner cube (1010) via the optical path length correction member (1008) and the dispersion compensation member (1009). The optical path length correction member (1008) acts as a delay means for matching the optical path lengths (optical distances) of the reference light (LR) and the measurement light (LS). The dispersion compensating member (1009) acts as a dispersion compensating means for matching the dispersion characteristics of the reference light (LR) and the measurement light (LS).
The corner cube (1010) turns back the traveling direction of the reference light (LR) which has become a parallel luminous flux by the collimator (1007) in the opposite direction. The optical path of the reference light (LR) incident on the corner cube (1010) is parallel to the optical path of the reference light (LR) emitted from the corner cube (1010). Further, the corner cube (1010) is movable in the direction along the incident optical path and the outgoing optical path of the reference light (LR). This movement changes the length of the optical path (reference optical path) of the reference light (LR).

As shown in FIG. 3, the reference light (LR) via the corner cube (1010) passes through the dispersion compensating member (1009) and the optical path length correction member (1008), and is focused from the parallel light beam by the collimator (1011). It is converted into a light beam, incident on the optical fiber (1012), and guided by the polarization controller (1013) to adjust the polarization state of the reference light (LR).
The polarization controller (1013) has, for example, the same configuration as the polarization controller (1003). The reference light LR whose polarization state is adjusted by the polarization controller (1013) is guided to the attenuator (1015) by the optical fiber (1014), and the amount of light is adjusted under the control of the control unit (12). The reference light (LR) whose light amount is adjusted by the attenuator (1015) is guided to the fiber coupler (1017) by the optical fiber (1016).

As shown in FIG. 3, the measurement light (LS) generated by the fiber coupler (1005) is guided to the optical fiber (501), while the measurement light emitted from the optical fiber (501) is shown in FIG. It is guided to the collimating lens (502) so as to be. Then, as shown in FIG. 1, the measurement light incident on the collimating lens (502) is the illumination field diaphragm (503), the scanners (504a, 504b), the relay optical system (505), and the first lens group (506). The eye to be inspected (8) is irradiated via the second lens group (507), the reflection mirror (508), and the OCT objective lens (509). The measurement light is reflected and scattered at various depth positions of the eye to be inspected (8). The backscattered light of the light measured by the eye to be inspected (8) travels in the same direction as the outward path in the opposite direction, is guided to the fiber coupler (1005), and passes through the optical fiber (1018) as shown in FIG. Then, it reaches the fiber coupler (1017).

The fiber coupler (1017) synthesizes (interferes) the measurement light (LS) incidented via the optical fiber (1018) and the reference light (LR) incident via the optical fiber (1016). ) Generates interference light. The fiber coupler (1017) generates a pair of interference lights (LC) by branching the interference light between the measurement light (LS) and the reference light (LR) at a predetermined branching ratio (for example, 50:50). .. The pair of interference lights (LC) emitted from the fiber coupler (1017) are guided to the detector (1021) by two optical fibers (1019, 1020), respectively.

The detector (1021) has, for example, a pair of photodetectors that detect each pair of interference lights (LC), and a balanced photodiode (hereinafter referred to as "BPD") that outputs the difference between the detection results. ). The detector (1021) sends the detection result (detection signal) to the control unit (12). The control unit (12) forms a cross-sectional image by, for example, performing a Fourier transform or the like on the spectral distribution based on the detection result obtained by the detector (1021) for each series of wavelength scans (for each A line). .. The control unit (12) causes the display unit (13) to display the formed image.

In this embodiment, a Michaelson type interferometer is adopted, but for example, any type of interferometer such as a Mach-Zehnder type can be appropriately adopted.

FIG. 4 is a cross-sectional view schematically showing the arrangement of optical paths around the objective lens in the ophthalmic microscope of the first embodiment.
As shown in FIG. 4, the optical path (P-400L) of the observation optical system for the left eye, the optical path (P-400R) of the observation optical system for the right eye, and illumination are contained in the lens barrel of the microscope main body (6) for ophthalmology. The optical path of the optical system (P-300) and the optical path of the OCT optical system (P-500) are arranged.
Since the ophthalmic microscope of the present invention does not use a large-diameter objective lens, the optical paths of the respective optical systems can be independently controlled.

FIG. 5 is a front view schematically showing the optical configuration of the objective lens in the ophthalmic microscope of the first embodiment.
FIG. 5 (A) shows the configuration of the objective lens used in the ophthalmic microscope of the first embodiment, and FIG. 5 (B) shows the direction of the optical axis of each lens constituting the objective lens.

As shown in FIG. 5A, the objective lens (401) used in the ophthalmic microscope of the first embodiment is the first lens (401a) and an optical element (401b) that changes the direction of the optical axis. ), And a second lens (401c). The first lens (401a) is a concave lens having a negative power, the optical element (401b) that changes the direction of the optical axis is a wedge prism, and the second lens (401c) is a positive lens. It is a convex lens with power.
As shown in FIG. 5 (B), the optical axis (A-401a) of the first lens is inclined inward (the direction in which they intersect each other on the side of the eye to be inspected).

As described with reference to FIG. 1, when observing the posterior segment of the fundus such as the retina, the anterior lens is inserted in the optical path between the eye to be inspected and the objective lens, and the anterior segment such as the cornea and iris is removed. When observing, the front lens is detached from the optical path.
FIG. 6 is a schematic view showing a case where the front lens is inserted on the optical path between the eye to be inspected and the objective lens in the ophthalmic microscope of the first embodiment of the present invention. In the ophthalmic microscope of the present invention, a lens group composed of at least three optical elements is used as an objective lens, but in FIG. 6, this is schematically shown as one lens. As shown in FIG. 6, the focal length of the objective lens (401) is F1, and the position at the distance of F1 from the objective lens is the front focal length position (u0) of the objective lens. The luminous flux from the illumination optical system passes through the objective lens (401) and the front lens (14) and illuminates the inside of the eye to be inspected (8). The reflected light reflected by the retina (8a) in the eye to be inspected forms an image at the posterior focal position of the anterior lens (14). By matching the posterior focal position of the anterior lens (14) with u0, which is the anterior focal position of the objective lens (401), the focal point (observation focal plane) of the observation optical system is aligned with the retina (8a). The retina can be observed in focus.

Here, a case where a lens having a power (refractive power) of D as the front lens (14) is inserted into the optical path is shown in FIG. 6 (A), and has a power (refractive power) of D'greater than D. FIG. 6B shows a case where the front lens (14') is inserted on the optical path. Since the focal length of the front lens (14, 14') can be obtained from the reciprocal of the power (refractive power) of the lens, FIG. 6 is more than the focal length (F2) of the front lens in FIG. 6 (A). The focal length (F2') of the front lens in (B) is shorter. As is clear from comparing FIGS. 6 (A) and 6 (B), the distances (H1, H1') between the objective lens (401) and the front lens (14, 14') are the focal lengths. The case of FIG. 6 (A) using the long (low power) front lens (14) needs to be longer than the case of FIG. 6 (B). Further, the distance (H2, H2') between the objective lens (401) and the eye to be inspected (8) is also the case of FIG. 6 (A) using the front lens (14) having a long focal length (low power). Needs to be longer than in the case of FIG. 6 (B).

As is clear from the comparison between FIGS. 6 (A) and 6 (B) as described above, in order to align the focal point (observation focal plane) of the observation optical system with the retina, the focal length (power) of the front lens is used. ), It is necessary to change the distance between the objective lens and the eye to be inspected, and also to change the distance between the objective lens and the front lens.

The same can be said not only for the focal point of the observation optical system but also for the focal point of the OCT optical system. That is, when the objective lens (401) in FIG. 6 is replaced with the OCT objective lens (509), the rear focal position of the front lens (14) is changed to u0, which is the front focal position of the OCT objective lens (509). By matching, the focus (OCT scanning surface) of the OCT optical system is focused on the retina (8a), and the retina can be scanned in the focused state to obtain a tomographic image.
Here, as is clear from the comparison between FIGS. 6 (A) and 6 (B), the distance (H1, H1') between the OCT objective lens (509) and the front lens (14) is the focal length. The case of FIG. 6 (A) using the long (low power) front lens (14) needs to be longer than the case of FIG. 6 (B). Further, the distance (H2, H2') between the OCT objective lens (509) and the eye to be inspected (8) is also shown in FIG. 6 (A) using a front lens (14) having a long focal length (low power). It is necessary to make the case of (B) longer than the case of FIG. 6 (B).
Therefore, in order to align the focus (OCT scanning surface) of the OCT optical system with the retina, the distance between the OCT objective lens and the eye to be inspected is changed according to the focal length (power) of the front lens. It is necessary to change the distance between the OCT objective lens and the front lens.

The distance between the objective lens and the eye to be inspected can be changed by holding the ophthalmologic microscope with a positioning device and moving it up and down. FIG. 7 is a schematic view showing an ophthalmic microscope according to the first embodiment of the present invention and a positioning device for holding the microscope. As shown in FIG. 7, the positioning device includes a support (15), an arm (16), an XY fine movement device (17), and the like, which hold the ophthalmic microscope. The three-dimensional position of the ophthalmic microscope held in the positioning device can be moved manually or by an actuator built in the positioning device, and can be fixed by an electromagnetic lock or the like built in the positioning device so as not to move. it can. These actuators and electromagnetic locks are controlled by the control unit of the ophthalmic microscope.
The ophthalmic microscope has a surgeon's microscope (18) used by an ophthalmic surgeon who operates the eye to be inspected (8) and an assistant's microscope (19) used by the surgical assistant, both of which are covered. It is possible to perform surgery while observing the optometry. The three-dimensional position of the ophthalmic microscope can also be operated with the foot switch (21), and the surgeon can adjust the position of the ophthalmic microscope by operating the foot while holding the surgical instrument in both hands. Is. An objective lens (not shown) is provided at the lower end inside the lens barrel (22) of the ophthalmic microscope. Further, the front lens (14) can be inserted between the objective lens and the eye to be inspected (8) by the holding arm (23).

The distance between the objective lens and the eye to be inspected (8) can be changed by moving the ophthalmologic microscope up and down with a positioning device.
Further, the OCT objective lens (not shown) in the lens barrel (22) of the ophthalmic microscope in FIG. 7 is also moved up and down by the positioning device to move the distance between the objective lens and the eye (8) to be inspected. Can be changed.

For example, from the state where the front lens (14') whose power shown in FIG. 6 (B) is D'is inserted on the optical path, the front lens is inserted and removed, and the power shown in FIG. 6 (A) is obtained. When replaced with the front lens (14) which is D, the ophthalmologic microscope is moved upward to change the distance between the objective lens (401) and the eye to be inspected (8) from H2'to H2. You can change it.
In this case, the distance between the objective lens (401) and the front lens (14) is because the front lens (14) also moves upward by the same distance as the ophthalmic microscope moves upward. Remains H1'. Therefore, it is necessary to move the front lens (14) downward with respect to the objective lens (401) so that the distance between the objective lens (401) and the front lens (14) is set to H1.

As shown in FIG. 7, the distance between the objective lens and the front lens (14) can be changed by the front lens position adjusting mechanism (20).
The front lens position adjusting mechanism will be described below with reference to FIG.

FIG. 8 is a schematic view showing a peripheral portion of the front lens position adjusting mechanism in the ophthalmologic microscope according to the first embodiment of the present invention. An objective lens (not shown) is provided at the lower end inside the lens barrel (22) of the ophthalmic microscope. Then, the front lens (14) can be inserted into the optical path between the objective lens and the eye to be inspected by the holding arm (23). The front lens (14) can be attached to and detached from the holding plate (24) provided at the tip of the holding arm (23), and various types of front lenses (14) having different powers can be replaced and used. it can. A tag is attached to the front lens (14), and when the information is read by the tag detector (25) and transmitted to the control unit, the control unit determines the type of the front lens (14). be able to.
The control unit determines the type of the front lens (14) and refers to the information of the storage medium that stores the information on the focal length according to the type of the front lens, and the front lens (14) inserted into the optical path. 14) Acquire information on the focal length. The control unit calculates the distance between the objective lens and the front lens (14) for focusing on the observation target based on the acquired information, and controls the front lens position adjustment mechanism (20) to control the front lens position adjustment mechanism (20). Adjust the position of the front lens (14).

As shown in FIG. 8, the front lens position adjusting mechanism (20) has a support bracket (2001), penetrates a screw hole provided in the support bracket (2001), and extends in the vertical direction. A rotating screw (2002) is fitted. A movable plate (2003) is connected to the rotating screw (2002), and the movable plate (2003) and the holding arm (23) are connected by a connecting arm (2004).
The rotary screw (2002) can be manually rotated by pinching the fine movement adjustment knob (2005), whereby the movable plate (2003) can be moved up and down. Then, in conjunction with the vertical movement of the movable plate (2003), the front lens (14) connected to the movable plate (2003) via the connecting arm (2004) and the holding arm (23) is moved up and down. Is possible.

The rotating screw (2002) can also be rotated by a motor (2006) whose rotation is controlled by a control unit, whereby the front lens (14) can be automatically controlled to move up and down. ..
The control unit determines the type of the front lens (14), and based on the focal length (power) of the front lens (14), the objective lens and the front lens (14) for focusing on the observation target. Calculate the distance between. Then, the control unit controls the front lens position adjusting mechanism (20) so that the distance between the objective lens and the front lens (14) becomes the calculated distance, and adjusts the position of the front lens (14). It can be adjusted automatically.

For example, when the front lens (14') having the power shown in FIG. 6 (B) is replaced with the front lens (14) having the power shown in FIG. 6 (A), the front lens (14') is replaced with the front lens (14) having the power shown in FIG. The control unit determines the type of the front lens (14) and controls the front lens position adjustment mechanism so that the distance between the objective lens (401) and the front lens (14) is H1. Change automatically.
Then, using the positioning device shown in FIG. 7, the surgeon or the surgical assistant moves the position of the ophthalmologic microscope upward by manual operation or by operating the foot switch (21) or the like. At this time, the surgeon or the surgical assistant moves the position of the ophthalmologic microscope upward while observing the microscope until the fundus is in focus. Then, at the in-focus position, the distance between the objective lens and the eye to be inspected (8) is H2 shown in FIG. 6 (A).
In this way, after automatically changing the distance between the objective lens and the anterior lens, the ophthalmic microscope can be moved upward until it is in focus by microscopic observation, but it should be focused by automatic control. You can also. For example, the control unit of the ophthalmic microscope uses the objective lens (401) and the eye to be inspected (401) shown in FIG. 6 (A) to focus on the observation target according to the focal length (power) of the front lens (14). It is also possible to calculate the distance (H2) between 8) and control the actuator of the positioning device shown in FIG. 7 to automatically move the ophthalmologic microscope upward.

In FIG. 8, the distance between the OCT objective lens (not shown) inside the lens barrel (22) of the ophthalmic microscope and the front lens (14) is also automatically determined by the front lens position adjustment mechanism (20). Can be adjusted.
That is, the control unit determines the type of the front lens (14) and adjusts the focus (OCT scanning surface) of the OCT optical system to the observation target based on the focal length (power) of the front lens (14). The distance between the OCT objective lens and the front lens (14) is calculated. Then, the control unit controls the front lens position adjusting mechanism (20) so that the distance between the OCT objective lens and the front lens (14) becomes the calculated distance of the front lens (14). The position can be adjusted automatically.

As shown in FIG. 8, the holding arm (23) and the front lens position adjusting mechanism (20) are held by a fixed bracket (26) connected to the lens barrel (22). The holding arm (23) and the front lens position adjusting mechanism (20) can rotate with respect to the axial center of the fixed bracket (26), whereby between the objective lens and the eye to be inspected. The front lens (14) can be inserted and removed on the optical path of.
When the front lens (14) is inserted into the optical path, the image of the eye to be inspected is inverted and becomes an inverted image. Therefore, a lens unit for returning this to a normal image is provided in the inverter unit (27). As the optical system of the lens unit provided in the inverter unit (27), for example, the one disclosed in Japanese Patent Publication No. 7-48091 can be used. The lens unit can be manually inserted and removed on the optical path in the lens barrel with the switching lever (28) in conjunction with the insertion and removal of the front lens, and the actuator is operated in conjunction with the insertion and removal of the front lens. By operating it, it can be automatically inserted and removed on the optical path inside the lens barrel.

FIG. 9 is a schematic diagram comparing the difference in optical path length between the case where the front lens is inserted in the optical path between the objective lens and the eye to be inspected and the case where the front lens is removed. FIG. 9A shows a case where the anterior segment such as the cornea and the iris is observed without inserting the anterior lens between the objective lens and the eye to be inspected, and FIG. 9B shows the objective lens and the subject. The case where the anterior lens is inserted during the optometry to observe the posterior segment of the eye such as the retina of the fundus is shown.
As is clear from the comparison between FIGS. 9 (A) and 9 (B), FIG. 9 (B) observes the posterior eye portion by inserting the anterior lens into the optical path between the objective lens and the eye to be inspected. In this case, the optical path length of the measurement light of the OCT optical system becomes longer than in the case of FIG. 9A in which the anterior segment of the eye is observed without inserting the front lens. The difference is the optical path length in one side, which is F2 (focal length of the front lens) x 2 + axial length (distance from the apex of the cornea to the fundus).

As described above, in OCT, when the measurement light and the reference light interfere with each other, it is necessary to pass the measurement light and the reference light by the same distance, so that the optical path length of the measurement light and the optical path length of the reference light must be the same. is there. Therefore, when the optical path length of the measurement light is increased by inserting the front lens into the optical path, it is necessary to lengthen the optical path length of the reference light accordingly.
In the ophthalmic microscope of the first embodiment, the corner cube (1010) in the OCT unit shown in FIG. 3 is moved in conjunction with the insertion / removal of the anterior lens on the optical path to obtain the reference light. The length of the optical path can be automatically increased by a certain value.
As described above, in the case of FIG. 9B in which the front lens is inserted in the optical path, the optical path length of the measurement light is unilateral as compared with the case of FIG. 9 (A) in which the front lens is not inserted in the optical path. The optical path length of is increased by "F2 x 2 + axial length". Therefore, the length of the optical path of the reference light is obtained by automatically moving the reference position of the corner cube (1010) shown in FIG. 3 by "F2 x 2 + axial length" in conjunction with the insertion of the front lens. Can be lengthened by "F2 x 2 + axial length" in the optical path length in one side. Here, the average axial length of a human is used as the "axial length", but since the axial length varies from person to person, in the ophthalmic microscope of the first embodiment, the optical path length of the reference light is minute. It is possible to adjust.

3. 3. Control mechanism In the ophthalmic microscope of the present invention, a) a lens discrimination mechanism that acquires information on the focal length of the front lens inserted in the optical path between the eye to be inspected and the objective lens, and b) the objective lens and the front. A position adjustment mechanism that adjusts the distance between the lenses and / or the distance between the OCT objective lens and the front lens, and c) a position adjustment mechanism based on information about the focal length of the front lens acquired by the lens discrimination mechanism. It is preferable to have a control mechanism for controlling the lens.

Here, the "focal length information" may be not only the value of the focal length of the front lens itself, but also any information corresponding to the focal length of the front lens, for example. Although not limited, it may be a value related to the power (refractive power) of the front lens, which is the reciprocal of the focal length, or ID information of the front lens.
Further, the lens discrimination mechanism of a) may be any mechanism as long as it can acquire information on the focal length of the front lens inserted in the optical path and transmit it to the control mechanism. .. For example, although not limited to these, a tag including a focal length value is attached to the front lens, the focal length value of the front lens is acquired by a tag reader, and the value is transmitted to the control mechanism. It may be. Further, an ID tag may be attached to the front lens so that the ID information of the front lens can be acquired by a tag reader. In this case, the control mechanism acquires the ID information of the front lens and accesses the information of the storage medium to acquire the value of the focal length corresponding to the ID of the front lens, thereby inserting the lens into the optical path. It is possible to obtain the value of the focal length of the front lens to be used.
The tags used here are not limited to these, but include, for example, wireless tags such as RFID tags and IC tags, tags that record information by magnetism, tags that record information by barcodes, and the like. Can be used.

The position adjustment mechanism of b) is any as long as it can adjust the distance between the objective lens and the front lens and / or the distance between the objective lens for OCT and the front lens. It may be. For example, although not limited to these, a mechanical mechanism capable of moving all of the objective lens, the OCT objective lens, and the front lens with respect to the main body of the ophthalmic microscope by the power of the actuator. Can be done. Further, it may be a mechanical mechanism that simultaneously changes both the distance to the objective lens and the distance to the OCT objective lens by moving only the front lens with respect to the main body of the ophthalmic microscope by the power of the actuator.

The control mechanism of c) may be any one as long as it controls the position adjustment mechanism based on the information regarding the focal length of the front lens acquired by the lens discrimination mechanism. For example, although not limited to these, the focal length value (F1) of the objective lens (401) and the focal length value (F2) of the front lens (14) shown in FIG. 6 (A) are set. The motor (2006) of the front lens position control mechanism (20) shown in FIG. 8 is calculated by adding the H1 so that the distance between the objective lens (401) and the front lens (14) is H1. Can be an electronic circuit that controls.

4. Second and Third Embodiments Next, examples of other embodiments of the present invention will be described with reference to the drawings.
FIG. 10 schematically shows the arrangement of optical paths around the objective lens in the ophthalmic microscope of the second embodiment and the ophthalmic microscope of the third embodiment, which are other examples of the ophthalmic microscope of the present invention. It is a cross-sectional view.
FIG. 10 (A) shows the arrangement of the optical path around the objective lens of the ophthalmic microscope of the second embodiment, and FIG. 10 (B) shows the optical path around the objective lens of the ophthalmic microscope of the third embodiment. Indicates the arrangement of.

As shown in FIG. 10A, in the ophthalmic microscope of the second embodiment, the optical path (P-400L) of the observation optical system for the left eye is contained in the lens barrel of the ophthalmic microscope main body (6). In addition to the optical path of the observation optical system for the right eye (P-400R), the optical path of the illumination optical system (P-300), and the optical path of the OCT optical system (P-500), the optical path for the left eye of the sub-observation optical system. (P-400SL) and an optical path for the right eye (P-400SR) are arranged.
The sub-observation optical system is used by an assistant observer other than the main observer (operator) to observe the eye to be inspected.
Since the ophthalmic microscope of the present invention does not use a large-diameter objective lens, it is possible to arrange the optical paths of many optical systems independently in this way.

As shown in FIG. 10B, in the ophthalmic microscope of the third embodiment, the optical path (P-400L) of the observation optical system for the left eye is located near the center of the lens barrel of the ophthalmic microscope main body (6). The optical path of the observation optical system for the right eye (P-400R), the optical path of the illumination optical system (P-300), and the optical path of the OCT optical system (P-500) are arranged so as to be concentrated. As a result, the angle formed by each optical path can be reduced without overlapping the optical path of the observation optical system and the optical path of the OCT optical system, thus expanding the range in which shape observation with a microscope and tomographic observation with OCT can be performed at the same time. be able to.

5. Configuration of Objective Lens The objective lens used in the ophthalmic microscope of the present invention is an objective composed of at least a first lens, an optical element that changes the direction of the optical axis, and a second lens. It is a lens.
Here, the first lens, the optical element that changes the direction of the optical axis, and the second lens may be arranged in any order.
Further, another lens or an optical element can be added to these lenses to form a lens group used as an objective lens.

In addition, any lens can be used as the first lens and the second lens, and they can be appropriately designed so that the eye to be inspected can be focused and magnified. Preferably, either one of the first lens and the second lens is a convex lens having a positive power, and the other is a concave lens having a negative power.

As the optical element for changing the direction of the optical axis, any optical element capable of changing the direction of the optical path can be used, and the optical element is not limited to these, but for example, refraction / reflection. A prism that changes the optical path can be used. As such a prism, for example, a wedge prism, a longoid type prism whose direction and orientation of the optical axis can be changed, and the like can be used.

When the first lens, the optical element that changes the direction of the optical axis, and the second lens are arranged in this order from the side of the eye to be inspected, the optical element that changes the direction of the optical axis left and right. The direction of the optical axis of the observation optical system is changed so that it intersects on the side of the eye to be inspected. Therefore, the optical axis of the first lens of the observation optical system for the left eye and the optical axis of the first lens of the observation optical system for the right eye are inclined in the direction of intersecting each other on the side of the eye to be inspected. Is preferable. Here, the "optical axis of the lens" is different from the "optical axis of the optical system" and means the optical axis of the lens alone.

Further, when the first lens, the optical element for changing the direction of the optical axis, and the second lens are arranged in this order from the side of the eye to be inspected, the second lens of the observation optical system for the left eye is used. It is preferable that the optical axis of the lens and the optical axis of the second lens of the observation optical system for the right eye are inclined in a direction away from each other on the side of the eye to be inspected.
With such a configuration, it is possible to greatly improve the problem that the focus difference in the periphery is reversed in the images of the left and right eyes as shown in FIG.

6. Fourth Embodiment FIG. 11 is a front view schematically showing an optical configuration of an objective lens in the ophthalmic microscope of the fourth embodiment, which is another example of the ophthalmic microscope of the present invention.
FIG. 11A shows the configuration of the objective lens used in the ophthalmic microscope of the fourth embodiment, and FIG. 11B shows the direction of the optical axis of each lens constituting the objective lens.

As shown in FIG. 11A, the objective lens (401) used in the ophthalmic microscope of the fourth embodiment is the first lens (401a) and an optical element (401b) that changes the direction of the optical axis. ), And a second lens (401c). The first lens (401a) is a concave lens having a negative power, the optical element (401b) that changes the direction of the optical axis is a wedge prism, and the second lens (401c) is a positive lens. It is a convex lens with power.

As shown in FIG. 11B, the optical axes (A-401c) of the second lens are inclined in a direction away from each other on the side of the eye to be inspected.
With such a configuration, it is possible to greatly improve the problem that the focus difference in the periphery is reversed in the images of the left and right eyes as shown in FIG.

7. Fifth Embodiment FIG. 12 is a front view schematically showing an optical configuration of an objective lens in the ophthalmic microscope of the fifth embodiment, which is another example of the ophthalmic microscope of the present invention.
FIG. 12 (A) shows the configuration of the objective lens used in the ophthalmic microscope of the fifth embodiment, and FIG. 12 (B) shows the direction of the optical axis of each lens constituting the objective lens.

As shown in FIGS. 12A and 12B, the objective lens (401) used in the ophthalmologic microscope of the fifth embodiment has a wedge prism (401b) and negative power from the side of the eye to be inspected. A concave lens (401a) having a positive power and a convex lens (401c) having a positive power are arranged in this order.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and changes in conditions that do not deviate from the gist are all within the scope of the present invention.

The ophthalmic microscope of the present invention is an ophthalmic microscope that can correct residual aberrations, has aberrations and focus differences that are nearly even on the left and right, and is suitable for binocular vision, and has a small objective lens. It can be used in the optical equipment industry and the medical equipment-related industry because the OCT device and another optical system can be easily installed.

1 Ophthalmic microscope 2 Subject 300 Illumination optics 301 Optical fiber 302 Emission light aperture 303 Condenser lens 304 Illumination field aperture 305 Collimated lens 306 Reflection mirror 400 Observation optics 400L Observation optics for left eye 400R Observation optics for right eye System 401 Objective lens 401a First lens 401b Optical element that changes the direction of the optical axis 401c Second lens 402 Variable magnification lens 402a, 402b, 402c Zoom lens 403 Beam splitter 404 Imaging lens 405 Image erecting prism 406 Eye width Adjusting prism 407 Field aperture 408 Eyepiece lens 500 OCT Optical system 501 Optical fiber 502 Collimating lens 503 Illumination field aperture 504a, 504b Scanner 505 Relay optical system 506 First lens group 507 Second lens group 508 Reflective mirror 509 Objective lens for OCT 6 Ophthalmology Microscope body 8 Subject 8a Retina 9 Illumination light source 10 OCT unit 1001 OCT light source unit 1002 Optical fiber 1003 Polarization controller 1004 Optical fiber 1005 Fiber coupler 1006 Optical fiber 1007 Collimeter 1008 Optical path length correction member 1009 Dispersion compensation member 1010 Corner cube 1011 Collimeter 1012 Optical Fiber 1013 Polarization Controller 1014 Optical Fiber 1015 Attenuator 1016 Optical Fiber 1017 Fiber Coupler 1018 Optical Fiber 1019 Optical Fiber 1020 Optical Fiber 1021 Detector 1101 Imaging Lens 1102 TV Camera 1102a Imaging Element 12 Control Unit 13 Display 14, 14' Front lens 15 Strut 16 Arm 17 XY fine movement device 18 Operator microscope 19 Assistant microscope 20 Front lens position adjustment mechanism 2001 Support bracket 2002 Rotating screw 2003 Movable plate 2004 Connecting arm 2005 Fine movement adjustment knob 2006 Motor 21 Foot Switch 22 Lens barrel 23 Holding arm 24 Holding plate 25 Tag detector 26 Fixed bracket 27 Inverter part 28 Switching lever A-401 Optical axis of objective lens A-402 Optical axis of variable magnification lens A-401a Optical axis of first lens A-401c Optical axis of the second lens F1 Focus distance of the objective lens F2, F2'Focus distance of the front lens H1, H1' Distance between the objective lens and the front lens H2, H2', H2'" Objective lens And the eye to be examined Distance between O-300 Optical axis of illumination optical system O-400 Optical axis of observation optical system O-400L Optical axis of observation optical system for left eye O-400R Optical axis of observation optical system for right eye O-500 OCT Optical path P-300 Optical path of illumination optical system P-400L Optical path of observation optical system for left eye P-400R Optical path of observation optical system for right eye P-400SL Optical path for left eye of sub-observation optical system P- 400SR Optical path for the right eye of the secondary observation optical system P-500 Optical path of the OCT optical system Q400L Focus position of the observation optical system for the left eye Q400R Focus position of the observation optical system for the right eye V400L Image for the left eye V400R For the right eye Image L0 Light output from the OCT light source unit LC Interference light LS Measurement light LR Reference light U0 Front focal position

Claims (6)

An illumination optical system that illuminates the eye to be inspected, an observation optical system having an observation optical system for the left eye and an observation optical system for the right eye for observing the eye to be inspected illuminated by the illumination optical system, and optical coherence stromography. For ophthalmologists, the OCT optical system having an optical path of measurement light and an optical path of reference light for inspecting the eye to be inspected, and a front lens that can be inserted and removed on the optical path between the eye to be inspected and the objective lens. In the microscope
In the ophthalmic microscope, the optical axis of the observation optical system for the left eye and the optical axis of the observation optical system for the right eye are substantially parallel.
The observation optical system for the left eye and the observation optical system for the right eye each have an objective lens.
The objective lens includes a first lens, an optical element that changes the direction of the optical axis, and a lens group having at least a second lens.
The objective lens changes the direction of the optical axis of the left eye observation optical system and the direction of the optical axis of the right eye observation optical system so as to intersect each other on the side of the eye to be inspected.
The OCT optical system is arranged in the region between the left eye observation optical system and the right eye observation optical system, and the OCT objective lens through which the optical axis of the OCT optical system is transmitted is separate from the objective lens. Have and
When the front lens is inserted into the optical path between the eye to be inspected and the objective lens, the optical axis of the observation optical system and the optical axis of the OCT optical system pass through the front lens.
The distance of the following 1) or 2) automatically changes according to the focal length of the front lens inserted in the optical path between the eye to be inspected and the objective lens.
1) Distance between the objective lens and the front lens 2) Distance between the OCT objective lens and the front lens The front lens is inserted and removed on the optical path between the eye to be inspected and the objective lens. An ophthalmic microscope characterized in that the length of the optical path of the reference light of the OCT optical system is automatically changed according to the focal distance of the front lens. A lens discrimination mechanism that acquires information on the focal length of the front lens inserted in the optical path between the eye to be inspected and the objective lens.
A position adjusting mechanism for adjusting the distance between the objective lens and the front lens and / or the distance between the OCT objective lens and the front lens.
The ophthalmologic microscope according to claim 1, further comprising a control mechanism for controlling a position adjustment mechanism based on information regarding a focal length of the front lens acquired by the lens discrimination mechanism. The ophthalmic microscope according to claim 1 or 2, wherein the optical element for changing the direction of the optical axis is a wedge prism. The ophthalmic use according to any one of claims 1 to 3, wherein the first lens is a concave lens having a negative power, and the second lens is a convex lens having a positive power. microscope. In the objective lens, the first lens, the optical element that changes the direction of the optical axis, and the second lens are arranged in this order from the side of the eye to be inspected.
The optical axis of the first lens of the left eye observation optical system and the optical axis of the first lens of the right eye observation optical system are inclined in a direction in which they intersect each other on the side of the eye to be inspected. The ophthalmic microscope according to any one of claims 1 to 4, wherein the microscope is provided. In the objective lens, the first lens, the optical element that changes the direction of the optical axis, and the second lens are arranged in this order from the side of the eye to be inspected.
The optical axis of the second lens of the left eye observation optical system and the optical axis of the second lens of the right eye observation optical system are inclined in a direction away from each other on the side of the eye to be inspected. The ophthalmic microscope according to any one of claims 1 to 5, wherein the microscope is characterized by the above.

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