JP2018166927A - Ophthalmic microscope - Google Patents

Abstract

To provide an ophthalmic microscope that is preferable for binocular vision and enables easy installation of another optical system.SOLUTION: In an ophthalmic microscope 6, an optical axis O-400L of a left eye observation optical system and an optical axis O-400R of a right eye observation optical system are approximately in parallel, each of the left eye observation optical system 400L and the right eye observation optical system 400R including an objective lens 401. The objective lens 401 is composed of a lens group including at least a first lens 401a, an optical element 401b for changing the optical axis's direction, and a second lens 401c. Directions of the optical axis O-400L of the left eye observation optical system and the optical axis O-400R of the right eye observation optical system are changed by the objective lens 401 into directions crossing each other at a side of an eye to be inspected.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an ophthalmic microscope. More specifically, the present invention relates to an ophthalmic microscope that is capable of correcting residual aberrations, and that the afterimage aberration of an image observed with the left and right eyes is close to the left and right, and is suitable for binocular vision. More specifically, the present invention relates to an ophthalmic microscope in which an objective lens can have a small diameter and another optical system such as an OCT apparatus can be easily installed.

  In the field of ophthalmology, various types of ophthalmic microscopes are used for magnifying and observing the eye. Examples of such an ophthalmic microscope include a fundus camera, a slit lamp, and a surgical microscope. These ophthalmic microscopes have a binocular optical system that provides binocular parallax generated between the left eye and the right eye in order to stereoscopically observe the eye.

A typical conventional ophthalmic microscope is a Galileo stereo microscope. The technical feature of the Galileo stereo microscope is that it has an objective lens that transmits the optical axes of the left and right observation optical systems in common, and that the optical axes of the left and right observation optical systems are basically parallel. It is said. The Galileo stereo microscope has an advantage that it can be easily combined with other optical systems and optical elements.
On the other hand, in the Galileo-type actual microscopic environment, since the objective lens and the imaging optical system are decentered, the residual aberration is reversed in the left and right directions, and it is difficult to reduce the residual aberration.

The present inventors have previously developed an ophthalmic microscope that employs a Greenough-type stereomicroscope, which is a system different from the Galileo stereomicroscope (Patent Documents 1 and 2). The Greenough-type stereomicroscope is a microscope that has two independent observation optical systems on the left and right sides and is arranged so that the optical axes of the left and right observation optical systems intersect. The Greenough-type stereomicroscope does not use a common objective lens, and each of the left and right observation optical systems includes an objective lens.
According to the Greenough microscopic environment, 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 two independent observation optical systems are obliquely crossed. .

  By the way, as an inspection apparatus that can be combined with an ophthalmic microscope, there is an OCT (Optical Coherence Tomography) apparatus. The OCT apparatus can be used for acquiring cross-sectional images and three-dimensional images of the eye, measuring the size of the eye tissue (such as retinal thickness), and acquiring functional information of the eye (such as blood flow information).

Many devices that incorporate an OCT device into an ophthalmic microscope have been developed, but most of them are devices in which the optical path of the OCT optical system passes through an objective lens in a Galileo stereomicroscope (Patent Documents 3 to 7). .
In addition, a method has been developed in which the optical path of the OCT optical system does not pass through the objective lens in the Galileo-type actual microscopic environment (Patent Document 8), but the OCT optical system is provided between the objective lens and the eye to be examined.

  Note that when performing observation using an ophthalmic microscope, there is a method of using a front lens in order to switch between observation of the anterior segment such as the cornea and iris and observation of the posterior segment such as the retina. In this method, it is possible to observe the posterior eye portion of the retina and the like by inserting a front lens on the optical path between the eye to be examined and the objective lens, and by removing the front lens from the optical path, Observation of the anterior eye part such as an iris becomes possible (Patent Document 9).

JP, 2006-185177, A JP, 2006-185178, A JP-A-8-66421 JP 2008-264488 A JP 2008-268852 A Special table 2010-522020 gazette JP 2008-264490 A US Pat. No. 8,366,271 Japanese Patent Laid-Open No. 2003-062003

  As schematically shown in FIG. 13A, the Galileo stereo microscope employed in the conventional ophthalmic microscope system includes the optical axis (O400L) of the left-eye observation optical system and the right-eye observation optical system. An objective lens (401) that transmits the optical axis (O400R) in common is provided. The observation optical system for the left and right eyes includes, for example, a variable power lens (402), an eyepiece lens (408), and the like. However, as schematically shown in FIG. 13B, the optical axis (A402) of the variable power lens and the optical axis (A401) of the objective lens are decentered by about 10 to 15 mm. For this reason, it is difficult to correct the residual aberration generated in the left and right eyes. Further, since the residual aberration is generated on the outer peripheral side of the objective lens (401), when the subject (2) is observed with both eyes, as shown in FIG. The left-eye image (V400L) and the right-eye image (V400R) occur on opposite sides, and there is a problem that different images must be observed with the left and right eyes. There are two types of Galilean stereomicroscopes, which have a convergence angle of 0 ° and a non-convergence angle of 0 °, but it is difficult to reduce the residual aberration by correction in either type. It was.

Further, the Galileo stereomicroscope has a demerit that the degree of freedom in optical design and mechanism 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 ophthalmic microscope in which an OCT optical system is incorporated in a Galileo stereomicroscope is a system in which the optical path of the OCT optical system is transmitted through an objective lens in the Galileo stereomicroenvironment. The OCT optical system and the observation optical system could not be made independent.
As a system in which the optical path of the OCT optical system does not pass through the objective lens at the Galileo stereomicroscope, as shown in Patent Document 8, there is a system in which an OCT optical system is provided below the objective lens. There was a problem that sufficient work space could not be secured.

On the other hand, in the Greenough-type stereomicroscope, as shown in FIG. 14A, the optical axis (O400L) of the left-eye observation optical system and the optical axis (O400R) of the right-eye observation optical system are obliquely intersected. The objective lens through which these optical axes are transmitted in common is not provided, and each optical system has an objective lens (401). As shown in FIG. 14B, the optical axis (A402) of the variable power lens and the optical axis (A401) of the objective lens are not decentered, and the residual aberration can be corrected, and occurs in the left and right eyes. There is no technical problem that lateral chromatic aberration and coma occur on the opposite sides of the left and right eyes. Furthermore, since the Greenough-type microscopic environment does not use a large-diameter objective lens, an OCT optical system can be provided independently between the left and right observation optical systems.
However, as shown in FIG. 14A, the Greenough-type entity microscopic boundary does not overlap the focus position (Q400L) of the left-eye observation optical system with the focus position (Q400R) of the right-eye observation optical system. As shown in FIG. 14C, there is a problem that the peripheral focus difference is reversed between the left and right eye images.
In addition, since the Greenough-type stereomicroscope obliquely crosses two independent observation optical systems, it has to be complicated in terms of mechanism, and it is difficult to assemble a variable magnification optical system. It was.

  Therefore, an object of the present invention is to eliminate the technical problems of conventional ophthalmic microscopes, to correct the residual aberration, and to make the residual aberration close to the left and right, so that it can be viewed in both eyes. It is to provide a suitable ophthalmic microscope. Another object of the present invention is to provide an ophthalmic microscope in which the objective lens can be made to have a small diameter and another optical system such as an OCT apparatus can be easily installed.

  As a result of intensive studies, the present inventors have abolished the large-diameter objective lens through which the left and right observation optical systems transmit in common, and provided the objective lens in each of the left and right observation optical systems, thereby decentering the lens. It has been found that the residual aberration can be corrected, and the objective lens can be reduced in diameter, so that another optical system can be easily installed. Furthermore, the present inventors set the objective lens as a lens group having at least a first lens, an optical element that changes the direction of the optical axis, and a second lens, thereby changing the left and right observation optical systems. It has been found that the optical axes can be crossed by the objective lens without obliquely crossing. Here, when the head lens is used to switch between the observation of the anterior eye portion and the observation of the posterior eye portion, the OCT scanning plane position and the observation focal plane position are determined according to the focal length (power) of the head lens. In addition, the optical path length of the measurement light of the OCT optical system changes due to the insertion / 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. 1) The distance between the objective lens and the front lens, 2) the distance between the OCT objective lens and the front lens, and 3) the length of the optical path of the reference light of the OCT optical system are respectively changed. The inventors have found that adjustment is possible, and have completed the present invention. Specifically, the present invention includes the following technical matters.

(1) The present invention provides an observation optical system that includes an illumination optical system that illuminates the eye to be examined, a left-eye observation optical system and a right-eye observation optical system for observing the subject eye illuminated by the illumination optical system. A system, an OCT optical system having an optical path of measurement light and an optical path of reference light for inspecting the eye by optical coherence tomography, and before being detachable on the optical path between the eye and the objective lens In an ophthalmic microscope equipped with a stationary lens,
In the ophthalmic microscope, the optical axis of the left-eye observation optical system and the optical axis of the right-eye observation optical system 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 A lens group having at least a lens,
By the objective lens, 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 are changed to intersect with each other on the eye side to be examined,
The OCT optical system in which the OCT optical system is disposed in a region between the left-eye observation optical system and the right-eye observation optical system and transmits the optical axis of the OCT optical system separately from the objective lens Have
When the front lens is inserted on the optical path between the eye to be examined and the objective lens, the optical axis of the observation optical system and the optical axis of the OCT optical system are transmitted through the front lens,
Depending on the focal length of the front lens inserted on the optical path between the eye to be examined and the objective lens, the following 1) or 2) distance automatically changes,
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 examined and the objective lens The ophthalmic microscope is characterized in that the length of the optical path of the reference light of the OCT optical system changes automatically according to the focal length of the front lens.
(2) In the ophthalmic microscope of the present invention, a lens discrimination mechanism that acquires information on the focal length of the front lens inserted on the optical path between the eye to be examined 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;
It is preferable to further include a control mechanism for controlling the position adjustment mechanism based on information on the focal length of the front lens acquired by the lens discrimination mechanism.
(3) In any one of the ophthalmic microscopes, it is preferable that the optical element that changes the direction of the optical axis is a wedge prism.
(4) In any one 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 one of the ophthalmic mirror microscopes, 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 eye side. If you are
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 a direction intersecting each other on the eye side to be examined. Preferably it is.
(6) In any one of the ophthalmic microscopes, 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 eye side. If you have
The optical axis of the second lens of the observation optical system for the left eye and the optical axis of the second lens of the observation optical system for the right eye are inclined in directions away from each other on the eye side to be examined. It is preferable.

  According to the present invention, it is possible to provide an ophthalmic microscope suitable for binocular vision that can correct residual aberration and has residual aberrations that are nearly equal to 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 the ophthalmic microscope, can have a small diameter, and another optical system such as an OCT apparatus can be easily installed. Is done. Furthermore, according to the present invention, it is possible to reduce the troublesome troublesome optical adjustment when the front lens is inserted and removed.

It is a front view which shows typically the structure of the optical system of the ophthalmic microscope of the 1st Embodiment of this invention. It is a side view which shows typically the structure of the optical system of the ophthalmic microscope of the 1st Embodiment of this invention. It is drawing which shows typically the optical structure of the OCT unit used with the ophthalmic microscope of the 1st Embodiment of this invention. It is sectional drawing which shows typically arrangement | positioning of the optical path in the periphery of the objective lens in the ophthalmic microscope of the 1st Embodiment of this invention. It is a front view which shows typically the optical structure of the objective lens in the ophthalmic microscope of the 1st Embodiment of this invention. FIG. 5A shows the configuration of the objective lens used in the ophthalmic microscope of the first embodiment, and FIG. 5B shows the direction of the optical axis of each lens constituting the objective lens. In the ophthalmic microscope of the first embodiment of the present invention, it is a drawing schematically showing a case where a front lens is inserted on an optical path between an eye to be examined and an objective lens. 6A shows a case where a lens having a power (refractive power) of D as a front lens is inserted on the optical path, and FIG. 6B shows a power (refractive power) of D ′ larger than D. The case where the front lens which has is inserted on the optical path is shown. It is drawing which shows typically the ophthalmic microscope of the 1st Embodiment of this invention, and the positioning device holding it. It is drawing which shows typically the peripheral part of the front lens position adjustment mechanism of the ophthalmic microscope of the 1st Embodiment of this invention. In the ophthalmic microscope according to the first embodiment of the present invention, the difference in optical path length between when the front lens is inserted on the optical path between the objective lens and the eye to be examined and when the front lens is detached is schematically shown. FIG. FIG. 9A shows a case where the anterior eye portion such as the cornea and the iris is observed without inserting the front lens between the objective lens and the eye to be examined, and FIG. The case where a front lens is inserted between the optometry and the posterior eye part such as the retina of the fundus is observed is shown. It is sectional drawing which shows typically arrangement | positioning of the optical path in the periphery of an objective lens in the ophthalmic microscope of the 2nd Embodiment of this invention, and the ophthalmic microscope of 3rd Embodiment. FIG. 10A shows the arrangement of the optical path around the objective lens of the ophthalmic microscope of the second embodiment, and FIG. 10B shows the optical path around the objective lens of the ophthalmic microscope of the third embodiment. The arrangement of It is a front view which shows typically the optical structure 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 structure of the objective lens in the ophthalmic microscope of 5th Embodiment of the ophthalmic microscope of this invention. FIG. 12A shows the configuration of the objective lens used in the ophthalmic microscope of the fifth embodiment, and FIG. 12B shows the direction of the optical axis of each lens constituting the objective lens. It is the schematic diagram which showed the image observed with a right-and-left eye by the Galileo type stereomicroscope which is a prior art, and the said stereomicroscope. FIG. 13A is a schematic diagram showing the configuration of the optical system of the observation optical system for the left and right eyes in the Galileo stereomicroscopic environment, and FIG. 13B shows the light of each lens in the Galileo stereomicroenvironment. FIG. 13C is a schematic diagram showing an image observed by the left and right eyes. It is the schematic which showed the image observed with a right-and-left eye with the Greeneau type | mold stereomicroscope which is a prior art, and the said stereomicroscope. FIG. 14A is a schematic diagram showing the configuration of the optical system of the observation optical system for the left and right eyes in the Greenough-type entity microenvironment, and FIG. 14B shows the light of each lens in the Greenough-type entity microenvironment. It is a schematic diagram which shows an axis | shaft, FIG.14 (C) is a schematic diagram which shows the elephant observed by the left and right eyes.

1. Overview of the Ophthalmic Microscope of the Present Invention An ophthalmic microscope of the present invention includes an illumination optical system that illuminates a subject eye, a left-eye observation optical system for observing the subject eye illuminated by the illumination optical system, and a right eye 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 by optical coherence tomography, and light between the eye to be examined and the objective lens The present invention relates to an ophthalmic microscope including a front lens that can be inserted and removed on a road.
Since the ophthalmic microscope of the present invention has the objective lens with a small aperture in each of the left-eye observation optical system and the right-eye observation optical system, the left-eye observation optical system and the right-eye observation optical system However, it is not necessary to use a large-diameter objective lens that transmits in common. For this reason, the decentration between the optical axis of the objective lens and the optical axis of the lens in front of it becomes small, and the residual aberration can be corrected. Further, the ophthalmic microscope of the present invention does not require the use of a large-diameter objective lens, and the objective lens can be reduced 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, as an objective lens, a lens group having at least a first lens, an optical element that changes the direction of the optical axis, and a second lens. With such an objective lens, the orientations of the optical axis of the left-eye observation optical system and the optical axis of the right-eye observation optical system are changed to intersect each other on the eye side. Therefore, the ophthalmic microscope according to the present invention has a 2 in the eye side of the eye more than the objective lens while the optical axis of the left-eye observation optical system and the optical axis of the right-eye observation optical system are substantially parallel in the ophthalmic microscope. Two optical axes can be crossed, and it is not necessary to use a complicated mechanism in which the left and right observation optical systems are arranged obliquely as in the case of a Greenough-type stereomicroscope.

In the present invention, the term “ophthalmic microscope” refers to a medical or examination device that can enlarge and observe an eye to be examined, and includes not only humans but also animals. “Ophthalmic microscope” includes, but is not limited to, a fundus camera, a slit lamp, an ophthalmic surgical microscope, and the like.
The ophthalmic microscope of the present invention is used for observing (taking) an enlarged image of an eye to be examined in medical treatment or surgery in the ophthalmic field. The observation target part may be an arbitrary part of the patient's eye. For example, the anterior segment may be a cornea, a corner, a vitreous body, a crystalline lens, a ciliary body, or the like, and the retinal segment may be a retina or choroid. Or a vitreous body. Further, the observation target part may be a peripheral part of the eye such as a eyelid or an eye socket.

The ophthalmic microscope of the present invention has an OCT optical system for examining the eye to be examined by optical coherence tomography in addition to a function as a microscope for observing the eye to be magnified, and functions as another ophthalmic apparatus. Can have. Examples of other functions as an ophthalmologic apparatus include laser treatment, axial length measurement, refractive power measurement, and higher-order aberration measurement. The function as another ophthalmologic apparatus includes an arbitrary configuration capable of performing examination, measurement, and imaging of the eye to be examined 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 and a light source, a display unit for displaying a captured image, and the like. These control units and display units may be different from the ophthalmic microscope.

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

In the present invention, the “observation optical system” is configured to include an optical element that makes it possible to observe the subject's eye with the return light reflected / scattered by the subject's eye illuminated by the illumination optical system. It is. In the present invention, the observation optical system has a left-eye observation optical system and a right-eye observation optical system. When parallax is generated in an image obtained by the left and right observation optical systems, binocular vision is used. It is also possible to observe three-dimensionally.
In addition, the “observation optical system” of the present invention may be one capable of observing the subject's eye with the naked eye of an observer through an eyepiece, an eyepiece, or the like. It may be possible, or it may have both functions.

In the present invention, the “OCT optical system” is configured to include an optical element that passes OCT measurement light and reference light. The OCT optical system can further include an OCT light source.
In the present invention, optical elements used in the “illumination optical system”, “observation optical system”, and “OCT optical system” are not limited to these. For example, lenses, prisms, mirrors, and optical filters are used. A diaphragm, a diffraction grating, a polarizing element, or 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. This means that the main path in the microscope is almost parallel, part of the optical axis may be non-parallel, and the main path may be parallel within a range of 5 ° or less. That's fine. However, in order to make it easier to arrange the lenses of the optical system, it is preferable to make them as close to 0 ° as possible and to make them parallel, and it is preferable to make them parallel within a range of 3 ° or less.

  In the present invention, the “objective lens” refers to a lens or a lens group provided on the eye side in an ophthalmic microscope. For example, when the objective lens is composed of three lens groups, the third lens from the eye side is the objective lens. When the objective lens is composed of four lens groups, the fourth lens from the eye side is the objective lens. However, the front lens (loupe) that is temporarily inserted between the objective lens and the eye to be examined 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 an 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 and reflection. And a wedge prism, a rhomboid prism capable of changing the position and orientation of the optical axis, and the like.

In the ophthalmic microscope of the present invention, the OCT optical system is disposed in a region between the left-eye observation optical system and the right-eye observation optical system, and the optical axis of the OCT optical system is separate from the objective lens of the observation optical system. Has an OCT objective lens through which light is transmitted.
When the front lens is inserted on the optical path between the eye to be examined and the objective lens, the optical axis of the observation optical system and the optical axis of the OCT optical system are transmitted through the front lens. Depending on the focal length (power), the OCT scanning plane position and the observation focal plane position change.
However, in the ophthalmic microscope of the present invention, the following distance 1) or 2) is automatically changed according to the focal length of the front lens inserted on the optical path between the eye to be examined 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 For this reason, in the ophthalmic microscope of the present invention, the OCT scanning plane position and the observation focal plane position are set as observation targets. Manual troublesome adjustment for matching can be reduced.

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

Further, in the ophthalmic microscope of the present invention, when the front lens is inserted / removed on the optical path between the eye to be examined 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 The difference between the length and the optical path length of the reference light changes and cannot be interfered 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 examined 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 automatically changes.
For this reason, in the ophthalmic microscope of the present invention, a tomographic image by OCT can be obtained correctly.

Here, “the front lens is inserted / removed” means not only that one type of front lens is inserted into and removed from the optical path between the eye to be examined and the objective lens, but also the front lens on the optical path. Including replacing the lens with another type of front lens.
In order to change the length of the optical path of the reference light of the OCT optical system, an optical element can be used. For example, but not limited to, the mirror at the turning point of the optical path of the reference light is moved. Thus, the optical path length can be changed, and the optical path length can be changed by inserting and removing the optical path length correcting member on the optical path of the reference light and by the difference in refractive index between the member and the atmosphere.

In the present invention, “the OCT optical system is arranged in a region between the left-eye observation optical system and the right-eye observation optical system” refers to the left-eye observation optical system when viewed from a certain direction. It means that an OCT optical system exists between the observation optical systems for the right eye.
In the present invention, “automatically changes” means the distance of 1) or 2) or the length of the optical path of the reference light of the OCT optical system, not by manual operation but by mechanical and / or electrical mechanisms. That changes.

2. First Embodiment Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.
FIGS. 1-9 is drawing which shows typically 1st Embodiment which is an example of the ophthalmic microscope of this invention. Among these drawings, FIG. 1 is a front view schematically showing the configuration of the optical system of the ophthalmic microscope according to the first embodiment, and FIG. 2 is a side view of the configuration of the optical system. FIG. 3 is a diagram schematically showing the optical configuration of the OCT unit, and FIG. 4 is a cross-sectional view schematically showing the arrangement of optical paths 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 including an observation optical system (400L) for the left eye of the observer and an observation optical system (400R) for the right eye. 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 examined (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 an ophthalmic microscope main body (6) indicated by a one-dot chain line. ing.

  In FIG. 1, the optical axis of the observation optical system for the left eye (400L) is indicated by a dotted line (O-400L), and the optical axis of the observation optical system for the right eye (400R) is indicated 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 within the ophthalmic microscope main body (6). It is parallel.
Therefore, the ophthalmic microscope (1) of the first embodiment does not need to be a complicated mechanism in which the left and right observation optical systems are arranged so as to cross like the Greenough-type 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 including 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) that changes the direction of the optical axis, and the base direction is the inside (base-in). The wedge prism changes the directions of the optical axes (O-400L, O-400R) of the left and right observation optical systems in a direction that intersects each other on the eye side.

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

The objective lens (401) used in the ophthalmic microscope according to the first embodiment has a large aperture that allows the optical axes of the left and right observation optical systems to pass through in common, as in the conventional Galileo stereomicroscope. 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 diameter, and the OCT optical system (500) can be easily installed between the left and right observation optical systems (400L, 400R). Can do.
Further, as shown in FIG. 1, the left and right objective lenses (401) change their orientation so that the optical axes (O-400L, O-400R) of the left and right observation optical systems intersect on the eye side to be examined. Therefore, the same part of the eye to be examined can be observed with both eyes with the left and right eyes.

Hereinafter, the ophthalmic microscope according to the first embodiment will be described in more detail.
As shown in FIG. 2, the illumination optical system (300) illuminates the eye to be examined (8), and includes an illumination light source (9), an optical fiber (301), an exit aperture stop (302), a condenser lens ( 303), an illumination field stop (304), a collimating lens (305), and a reflection mirror (306). The optical axes of these illumination optical systems (300) are indicated by dotted lines (O-300) in FIG.

The illumination light source (9) is provided outside the ophthalmic microscope body (6). One end of an optical fiber (301) is connected to the illumination light source (9). The other end of the optical fiber is disposed at a position facing the condenser lens (303) inside the ophthalmic microscope main body (6). The illumination light output from the illumination light source (9) is guided by the optical fiber (301) and enters the condenser lens (303).
An exit aperture stop (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 stop (302) acts to block a partial region of the exit aperture of the optical fiber (301). When the blocking area by the exit aperture stop (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 examined (8) and the optical axis of the objective lens (401) can be changed.

The illumination field stop (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 stop (304) into a parallel light flux. The reflection mirror (306) reflects the illumination light converted into a parallel light beam by the collimator lens (305) toward the objective lens (401). The reflected light is applied to the eye (8) to be examined.
Illumination light (a part) irradiated to the eye to be examined (8) is reflected and scattered by the tissue of the eye to be examined such as cornea and retina. The reflected / scattered return light (also referred to as “observation light”) enters the observation optical system (400).

As shown in FIG. 1, the left and right observation optical systems (400L, 400R) include an objective lens (401), a variable power lens (402), a beam splitter (403), an imaging lens (404), an image corrector, respectively. It includes an upright prism (405), an eye width adjustment prism (406), a field stop (407), and an eyepiece lens (408). The beam splitter (403) has only the 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 zoom mechanism (not shown). Thereby, the magnification at the time of observing or photographing the eye to be examined (8) is changed.

As shown in FIG. 1, the beam splitter (403) of the right-eye observation optical system (400R) transmits a part of the observation light guided along the right-eye observation optical path from the eye to be examined (8). Separate and guide to the photographic 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 imaging element (1102a) is configured by, for example, a charge coupled device (CCD) image sensor, a complementary metal oxide semiconductor (CMOS) image sensor, or the like. An image sensor (1102a) having a two-dimensional light receiving surface (area sensor) is used.
When the ophthalmic microscope (1) is used, the light receiving surface of the imaging element (1102a) is disposed at a position optically conjugate with the cornea or retina surface of the eye to be examined (8), for example.

The image erecting prism (405) converts the inverted image into an erect image. The eye width adjustment prism (406) is an optical element for adjusting the distance between the left and right observation optical paths in accordance with the eye width of the observer (the distance between the left eye and the right eye). The field stop (407) is for limiting the observer's field of view by blocking the peripheral region in the cross section of the observation light. The field stop (407) is provided at a position conjugate to the front focal position (U0) (X position) of the objective lens (401).
The observation optical system (400L, 400R) may include a stereo variator configured to be detachable from the optical path of the observation optical system. The stereo variator is an optical axis position changing element for changing the relative position of the optical axes (O-400L, O-400R) of the left and right observation optical systems respectively guided by the left and right variable magnification lens systems (402). is there. For example, the stereo variator is retracted to 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 eye part such as the retina of the fundus, the front lens (14) is moved to the optical axis O-400L, O-400R, Inserted on O-500. In this case, the front 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., observation is performed with the front lens detached from the front of the subject's eye.

  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 stop (503), a scanner (504a, 504b), and relay optics. The system includes a system (505), a first lens group (506), a second lens group (507), a reflection mirror (508), and an OCT objective lens (509).

  The OCT unit (10) divides light from an OCT light source having low coherence (short coherence distance) into measurement light and reference light. The measurement light is guided by the OCT optical system (500) and applied to the eye to be examined (8), and is reflected / scattered in the tissue of the eye to be examined, which is returned to the OCT unit (10). The OCT unit (10) detects interference between the return light of the measurement light and the reference light. Thereby, a tomographic image of the tissue of the eye to be examined can be obtained.

  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, whereby the ophthalmic microscope main body is connected. Linked with (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 collimated lens (502), illumination field stop (503), scanner (504a, 504b), relay optical system (505), first lens group (506), second lens group (507), reflection. The return light of the measurement light irradiated to the eye to be examined (8) via the mirror (508) and the OCT objective lens (509) and reflected / scattered by the tissue of the eye to be examined (8) travels in the reverse direction on 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 light 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 collimator 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 stop (503) is conjugate with the front focal position (U0) of the objective lens (401).

Scanners (504a, 504b) in the OCT optical system two-dimensionally change the direction of the measurement light that has been converted into a parallel light beam by the collimator lens (502). The scanner (504a, 504b) uses a reflecting member configured to be rotatable about two axes that intersect each other. Examples of the reflecting member include a galvanometer mirror, a polygon mirror, a rotating mirror, and a MEMS (Micro Electro Mechanical Systems) mirror. In the first embodiment, the scanner (504a, 504b) includes a galvanometer mirror. In other words, the scanner includes a first scanner (504a) having a reflective surface that can be rotated about a first axis, and a second scanner having a reflective surface that can be rotated about a second axis orthogonal to the first axis. (504b). A relay optical system (505) is provided between the first scanner (504a) and the second scanner (504b).
The first lens group (506) includes one or more lenses, and the second lens group (507) also includes one or more lenses.
The OCT objective lens (509) may be in an optically conjugate relationship with a member such as a galvanometer mirror. In that case, the diameter 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 the OCT unit (10) used in the ophthalmic microscope according to the first embodiment.
As shown in FIG. 3, the OCT unit (10) divides the light emitted from the OCT light source unit (1001) into measurement light (LS) and reference light (LR), and passes through another optical path (measurement light ( LS) and reference light (LR) constitute an interferometer that detects interference.
The OCT light source unit (1001) includes a wavelength scanning type (wavelength sweep type) light source capable of scanning (sweeping) the wavelength of emitted light, as in a general swept source type OCT apparatus. The OCT light source unit (1001) temporally changes the output wavelength at a near infrared wavelength that cannot be visually recognized by human eyes. The light output from the OCT light source unit (1001) is indicated by a symbol L0.

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

As shown in FIG. 3, the reference light (LR) is guided to the collimator (1007) by the optical fiber (1006) to become a parallel light beam. The reference light LR that has become a parallel light beam 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 unit for matching the optical path lengths (optical distances) of the reference light (LR) and the measurement light (LS). The dispersion compensation member (1009) acts as a dispersion compensation means for matching the dispersion characteristics of the reference light (LR) and the measurement light (LS).
The corner cube (1010) folds the traveling direction of the reference light (LR) that has become a parallel light beam by the collimator (1007) in the reverse direction. The optical path of the reference light (LR) incident on the corner cube (1010) and the optical path of the reference light (LR) emitted from the corner cube (1010) are parallel. The corner cube (1010) is movable in a direction along the incident optical path and the outgoing optical path of the reference light (LR). By this movement, the length of the optical path (reference optical path) of the reference light (LR) is changed.

As shown in FIG. 3, the reference light (LR) passing through the corner cube (1010) is converged from the parallel light flux by the collimator (1011) via the dispersion compensation member (1009) and the optical path length correction member (1008). It is converted into a light beam, enters the optical fiber (1012), is guided to the polarization controller (1013), and the polarization state of the reference light (LR) is adjusted.
The polarization controller (1013) has the same configuration as the polarization controller (1003), for example. 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 light quantity is adjusted under the control of the control unit (12). The reference light (LR) whose light quantity 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). The measurement light emitted from the optical fiber (501) is shown in FIG. To the collimating lens (502). As shown in FIG. 1, the measurement light incident on the collimating lens (502) includes an illumination field stop (503), a scanner (504a, 504b), a relay optical system (505), and a first lens group (506). The eye (8) is irradiated through 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 examined (8). The backscattered light of the measurement light from the eye to be inspected (8) travels in the same direction as the forward path in the reverse direction, and is guided to the fiber coupler (1005) and passes through the optical fiber (1018) as shown in FIG. Then, the fiber coupler (1017) is reached.

  The fiber coupler (1017) combines (interferes) the measurement light (LS) incident through the optical fiber (1018) and the reference light (LR) incident through the optical fiber (1016). ) Generate interference light. The fiber coupler (1017) generates a pair of interference light (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). . A pair of interference light (LC) emitted from the fiber coupler (1017) is guided to the detector (1021) by two optical fibers (1019, 1020), respectively.

  The detector (1021) has, for example, a pair of photodetectors that respectively detect a pair of interference lights (LC), and outputs a difference between detection results, thereby providing a balanced photodiode (hereinafter referred to as “BPD”). ). The detector (1021) sends the detection result (detection signal) to the control unit (12). For example, the control unit (12) forms a cross-sectional image by performing Fourier transform or the like on the spectrum 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) displays the formed image on the display unit (13).

  In this embodiment, a Michelson interferometer is used. However, for example, any type of interferometer such as a Mach-Zehnder type can be appropriately used.

FIG. 4 is a cross-sectional view schematically showing the arrangement of optical paths around the objective lens in the ophthalmic microscope according to 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 in the barrel of the ophthalmic microscope body (6) An optical path (P-300) of the optical system and an optical path (P-500) of the OCT optical system 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 made independent and controlled independently.

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

As shown in FIG. 5 (A), 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 the second lens (401c). The first lens (401a) is a concave lens having negative power, the optical element (401b) for changing the direction of the optical axis is a wedge prism, and the second lens (401c) is a positive lens. It is a convex lens having power.
As shown in FIG. 5B, the optical axis (A-401a) of the first lens is inclined inward (a direction intersecting with each other on the eye side to be examined).

As described with reference to FIG. 1, when observing the posterior segment of the retina of the fundus, an anterior lens is inserted on the optical path between the eye to be examined and the objective lens, and the anterior segment of the cornea, iris, etc. When observing, the front lens is detached from the optical path.
FIG. 6 is a schematic diagram showing a case where the front lens is inserted on the optical path between the eye to be examined and the objective lens in the ophthalmic microscope according to 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. 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 F1 from the objective lens is the front focal position (u0) of the objective lens. The light beam from the illumination optical system passes through the objective lens (401) and the front lens (14) to illuminate the inside of the eye to be examined (8). The reflected light reflected by the retina (8a) in the eye to be examined forms an image at the rear focal position of the front lens (14). By matching the rear focal position of the front lens (14) with u0 which is the front focal position of the objective lens (401), the focus (observation focal plane) of the observation optical system is adjusted to the retina (8a), The retina can be observed in focus.

  Here, FIG. 6A shows a case where a lens having a power (refractive power) of D as the front lens (14) is inserted in the optical path, and has a power (refractive power) of D ′ larger than D. FIG. 6B shows the 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, the focal length (F2) of the front lens in FIG. The focal length (F2 ′) of the front lens in (B) is shorter. As is clear by comparing FIG. 6A and FIG. 6B, the distances (H1, H1 ′) between the objective lens (401) and the front lenses (14, 14 ′) are the focal lengths. The case of FIG. 6A using a long (small power) front lens (14) needs to be longer than the case of FIG. 6B. In addition, the distance (H2, H2 ′) between the objective lens (401) and the eye to be examined (8) is also the case of FIG. 6A using the front lens (14) having a long focal length (small power). It is necessary to make this longer than in the case of FIG.

  As is clear from the comparison between FIG. 6A and FIG. 6B as described above, in order to focus the observation optical system (observation focal plane) on the retina, the focal length (power of the front lens) ), It is necessary to change the distance between the objective lens and the eye to be examined and to change the distance between the objective lens and the front lens.

The same applies to the focus of the OCT optical system as well as the focus of the observation 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 plane) of the OCT optical system is adjusted to the retina (8a), and the retina can be scanned in a focused state to obtain a tomographic image.
Here, as is clear from the comparison between FIGS. 6A and 6B, the distances (H1, H1 ′) between the OCT objective lens (509) and the front lens (14) are focal lengths. In the case of FIG. 6 (A) using the long front lens (14) having a long length (small power), it is necessary to make it longer than the case of FIG. 6 (B). Further, the distance (H2, H2 ′) between the OCT objective lens (509) and the eye to be examined (8) is also shown in FIG. 6A using the front lens (14) having a long focal length (small power). In this case, it is necessary to make the length longer than that in the case of FIG.
Therefore, in order to focus the OCT optical system (OCT scanning plane) on the retina, the distance between the OCT objective lens and the eye to be examined 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.

In order to change the distance between the objective lens and the eye to be examined, it is possible to change the distance by holding the ophthalmic microscope with a positioning device and moving it up and down. FIG. 7 is a schematic diagram showing an ophthalmic microscope according to the first embodiment of the present invention and a positioning device that holds the microscope. As shown in FIG. 7, the positioning device includes a column (15), an arm (16), an XY fine movement device (17), and the like, and holds an ophthalmic microscope. The three-dimensional position of the ophthalmic microscope held in the positioning device can be moved manually or by an actuator inherent in the positioning device, and can be fixed by an electromagnetic lock or the like inherent in the positioning device so as not to move. it can. These actuators and electromagnetic locks are controlled by a control unit of an ophthalmic microscope.
The ophthalmic microscope has an operator microscope (18) used by an ophthalmic surgeon operating the eye to be examined (8) and an assistant microscope (19) used by the surgical assistant. Surgery can be performed while observing the optometry. The three-dimensional position of the ophthalmic microscope can be operated with the foot switch (21), and the surgeon can adjust the position of the ophthalmic microscope with his / her foot while holding the surgical instrument in both hands. It is. An objective lens (not shown) is provided at the lower end inside the barrel (22) of the ophthalmic microscope. Further, the front lens (14) can be inserted between the objective lens and the eye to be examined (8) by the holding arm (23).

The distance between the objective lens and the eye to be examined (8) can be changed by moving the ophthalmic microscope up and down by the positioning device.
In addition, with respect to the OCT objective lens (not shown) in the lens barrel (22) of the ophthalmic microscope in FIG. 7, the distance to the eye to be examined (8) is moved by moving the ophthalmic microscope up and down by the positioning device. Can be changed.

For example, when the front lens (14 ′) whose power is D ′ shown in FIG. 6 (B) is inserted in the optical path, the front lens is inserted and removed, and the power shown in FIG. 6 (A) is obtained. When the front lens (14), which is D, is replaced, the ophthalmic microscope is moved upward to change the distance between the objective lens (401) and the eye to be examined (8) from H2 ′ to H2. Change it.
In this case, since the head lens (14) is also moved upward by the same distance in accordance with the upward movement of the ophthalmic microscope, the distance between the objective lens (401) and the head lens (14). Remains H1 ′. Therefore, it is necessary to move the front lens (14) downward with respect to the objective lens (401), and to set the distance between the objective lens (401) and the front lens (14) 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).
Hereinafter, the front lens position adjusting mechanism will be described with reference to FIG.

FIG. 8 is a schematic diagram showing a peripheral portion of the front lens position adjusting mechanism in the ophthalmic microscope according to the first embodiment of the present invention. An objective lens (not shown) is provided at the lower end inside the barrel (22) of the ophthalmic microscope. The front lens (14) can be inserted into the optical path between the objective lens and the eye to be examined by the holding arm (23). The front lens (14) can be attached to and detached from a holding plate (24) provided at the tip of the holding arm (23), and various types of the front lens (14) having different powers can be used by being replaced. it can. A tag is attached to the front lens (14). 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 discriminates the type of the front lens (14) and refers to the information of the storage medium storing the information on the focal length according to the type of the front lens (the front lens inserted into the optical path ( 14) information on the focal length is acquired. The control unit calculates a 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), 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), and extends vertically through a screw hole provided in the support bracket (2001). A rotating screw (2002) is fitted. A movable plate (2003) is coupled to the rotating screw (2002), and the movable plate (2003) and the holding arm (23) are coupled by a coupling arm (2004).
The rotating screw (2002) can be manually rotated by pinching the fine adjustment knob (2005), and thereby 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) is moved up and down via the connecting arm (2004) and the holding arm (23). Is possible.

The rotating screw (2002) can also be rotated by a motor (2006) whose rotation is controlled by the control unit, and thus the front lens (14) can be moved up and down by automatic control. .
The control unit discriminates 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 object. The distance between is calculated. Then, the control unit controls the front lens position adjustment mechanism (20) so that the distance between the objective lens and the front lens (14) is the calculated distance, thereby adjusting the position of the front lens (14). It can be adjusted automatically.

For example, when the front lens (14 ′) having the power D ′ shown in FIG. 6 (B) is replaced with the front lens (14) having the power D shown in FIG. 6 (A), 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.
After that, using the positioning device shown in FIG. 7, the surgeon or the surgical assistant moves the position of the ophthalmic microscope upward manually or by operating the foot switch (21) or the like. At this time, the surgeon or the surgical assistant moves the position of the ophthalmic microscope upward while focusing on the fundus while observing the microscope. Then, the distance between the objective lens and the eye to be examined (8) at the in-focus position is H2 shown in FIG.
In this way, after automatically changing the distance between the objective lens and the front lens, it is possible to move the ophthalmic microscope upward until the subject is in focus with microscope observation. You can also. For example, the control unit of the ophthalmic microscope controls the objective lens (401) shown in FIG. 6 (A) and the eye to be inspected (for focusing on the observation target according to the focal length (power) of the front lens (14). The distance (H2) between 8) can be calculated, and the actuator of the positioning device shown in FIG. 7 can be controlled to automatically move the ophthalmic 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 automatically set by the front lens position adjusting mechanism (20). Can be adjusted.
That is, the control unit discriminates the type of the front lens (14), and focuses the OCT optical system (OCT scanning plane) on the observation target based on the focal length (power) of the front lens (14). Therefore, the distance between the objective lens for OCT and the front lens (14) is calculated. Then, the control unit controls the front lens position adjustment mechanism (20) so that the distance between the OCT objective lens and the front lens (14) is the calculated distance, and controls 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 be rotated with respect to the axial center of the fixed bracket (26). The front lens (14) can be inserted into and removed from the optical path.
When the front lens (14) is inserted in the optical path, the image of the eye to be examined is inverted and becomes a reverse image. Therefore, a lens unit for returning this to the normal image is provided in the inverter (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 into and removed from the optical path in the lens barrel with the switching lever (28) in conjunction with the insertion / removal of the front lens, and the actuator can be operated in conjunction with the insertion / removal of the front lens. By operating, it can be automatically inserted into and removed from the optical path in the lens barrel.

FIG. 9 is a schematic diagram for comparing the difference in optical path length between when the front lens is inserted on the optical path between the objective lens and the eye to be examined and when the front lens is detached. FIG. 9A shows a case where the anterior eye portion such as the cornea and the iris is observed without inserting the front lens between the objective lens and the eye to be examined, and FIG. The case where a front lens is inserted between the optometry and the posterior eye part such as the retina of the fundus is observed is shown.
As is clear from the comparison between FIG. 9A and FIG. 9B, the front lens is inserted on the optical path between the objective lens and the eye to be examined, and the posterior eye portion is observed in FIG. 9B. 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 eye portion is observed without inserting the front lens. The difference is the optical path length in one direction, which is F2 (focal length of the front lens) × 2 + eye axis length (distance from the corneal apex to the fundus).

As described above, in the OCT, in order to cause the measurement light and the reference light to interfere with each other, it is necessary to pass the measurement light and the reference light through the same distance. Therefore, the optical path length of the measurement light and the optical path length of the reference light must be matched. is there. Therefore, if the optical path length of the measurement light is increased by inserting the front lens on the optical path, it is necessary to increase 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 front lens on the optical path, thereby 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 into the optical path as compared with the case of FIG. 9A in which the front lens is not inserted into the optical path, the optical path length of the measurement light is unidirectional. Is increased by “F2 × 2 + eye axis length”. Therefore, in conjunction with the insertion of the front lens, the reference position of the corner cube (1010) shown in FIG. 3 is automatically moved by “F2 × 2 + eye axis length”, thereby the length of the optical path of the reference light. Can be increased by “F2 × 2 + eye axis length” in the optical path length in one side direction. Here, the “ocular axial length” uses an average human axial axial length, and there are individual differences in the axial axial length. Therefore, in the ophthalmic microscope of the first embodiment, the optical path length of the reference light is very small. Adjustment is possible.

3. Control Mechanism In the ophthalmic microscope of the present invention, a) a lens discriminating mechanism that acquires information on the focal length of the front lens inserted on the optical path between the eye to be examined and the objective lens, and b) the objective lens and the front lens 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 on the focal length of the front lens acquired by the lens discrimination mechanism. It is preferable to have a control mechanism for controlling

Here, the “information on focal length” is not limited to the focal length value itself of the front lens, but may be any information as long as it is information corresponding to the focal length of the front lens. 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.
The lens discrimination mechanism 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, but not limited to this, a tag including the focal length value is attached to the front lens, and the focal length value of the front lens is acquired by a tag reader and transmitted to the control mechanism. It may be. Moreover, the aspect which can attach ID tag to a front lens and can acquire ID information of a front lens with a tag reader may be sufficient. In this case, the control mechanism acquires the ID information of the front lens and accesses the information in the storage medium to acquire the value of the focal length corresponding to the ID of the front lens, and thereby inserts it into the optical path. The value of the focal length of the front lens can be obtained.
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 using magnetism, tags that record information using barcodes, and the like. Can be used.

  The position adjustment mechanism of b) is any mechanism that can adjust the distance between the objective lens and the front lens and / or the distance between the OCT objective lens and the front lens. It may be. For example, although not limited thereto, a mechanical mechanism that can move all of the objective lens, the OCT objective lens, and the front lens with respect to the ophthalmic microscope main body by the power of the actuator is used. Can do. 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 ophthalmic microscope main body by the power of the actuator.

  The control mechanism of c) may be any mechanism as long as it controls the position adjustment mechanism based on information about the focal length of the front lens acquired by the lens discrimination mechanism. For example, the focal length value (F1) of the objective lens (401) and the focal length value (F2) of the front lens (14) shown in FIG. The motor (2006) of the front lens position control mechanism (20) shown in FIG. 8 is calculated by adding H1 so that the distance between the objective lens (401) and the front lens (14) is H1. The electronic circuit can be controlled.

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 according to the second embodiment and the ophthalmic microscope according to the third embodiment, which are other examples of the ophthalmic microscope of the present invention. It is sectional drawing.
FIG. 10A shows the arrangement of the optical path around the objective lens of the ophthalmic microscope of the second embodiment, and FIG. 10B shows the optical path around the objective lens of the ophthalmic microscope of the third embodiment. The arrangement of

As shown in FIG. 10 (A), in the ophthalmic microscope of the second embodiment, the optical path (P-400L) of the left-eye observation optical system is placed in the lens barrel of the ophthalmic microscope main body (6). In addition to the optical path (P-400R) of the observation optical system for the right eye, the optical path (P-300) of the illumination optical system, and the optical path (P-500) of the OCT optical system, the optical path for the left eye of the sub-observation optical system (P-400SL) and the optical path for the right eye (P-400SR) are arranged.
The sub-observation optical system is used by an observer who is an assistant other than the main observer (operator) to observe the eye to be examined.
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 as described above.

  As shown in FIG. 10B, in the ophthalmic microscope of the third embodiment, the optical path (P-400L) of the left-eye observation optical system is located near the center of the barrel of the ophthalmic microscope body (6). And the optical path (P-400R) of the observation optical system for the right eye, the optical path (P-300) of the illumination optical system, and the optical path (P-500) of the OCT optical system. This makes it possible to reduce the angle formed by the optical paths without overlapping the optical paths of the observation optical system and the OCT optical system, thereby expanding the range in which the shape observation by the microscope and the tomographic observation by the OCT can be performed simultaneously. be able to.

5. Configuration of Objective Lens The objective lens used in the ophthalmic microscope of the present invention is an objective consisting of a lens group including 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, other lenses and optical elements can be added to these lenses to form a lens group used as an objective lens.

  Moreover, any lens can be used for the first lens and the second lens, and the first lens and the second lens can be appropriately designed so that the eye to be examined can be enlarged while being focused. Preferably, 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.

  Any optical element that can change the direction of the optical path can be used as the optical element that changes the direction of the optical axis, and is not limited to these. A prism that changes the optical path can be used. As such a prism, for example, a wedge prism or a rhomboid prism capable of changing the position of the optical axis to the orientation 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 eye side, the optical element that changes the direction of the optical axis The direction of the optical axis of the observation optical system is changed so as to intersect on the eye side. For this reason, 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 so as to intersect with each other on the eye side to be examined. Is preferred. Here, the “lens optical axis” is different from the “optical axis of the optical system” and means the optical axis of a single lens.

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 eye side, the second lens of the left-eye observation optical system is arranged. It is preferable that the optical axis of the lens 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 eye to be examined.
By adopting such a configuration, it is possible to greatly improve the problem that the peripheral focus difference is reversed between the left and right eye images as shown in FIG.

6). Fourth Embodiment FIG. 11 is a front view schematically showing an optical configuration of an objective lens in an ophthalmic microscope according to a 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 the second lens (401c). The first lens (401a) is a concave lens having negative power, the optical element (401b) for changing the direction of the optical axis is a wedge prism, and the second lens (401c) is a positive lens. It is a convex lens having power.

As shown in FIG. 11B, the optical axes (A-401c) of the second lenses are inclined in directions away from each other on the eye side.
By adopting such a configuration, it is possible to greatly improve the problem that the peripheral focus difference is reversed between the left and right eye images as shown in FIG.

7). Fifth Embodiment FIG. 12 is a front view schematically showing an optical configuration of an objective lens in an ophthalmic microscope according to a fifth embodiment which is another example of the ophthalmic microscope of the present invention.
FIG. 12A shows the configuration of the objective lens used in the ophthalmic microscope of the fifth embodiment, and FIG. 12B 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 ophthalmic microscope according to the fifth embodiment has a wedge prism (401b) and negative power from the eye side. A concave lens (401a) having a positive power and a convex lens (401c) having a positive power are arranged in this order.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to above-described embodiment, The change of the conditions etc. which do not deviate from a summary are all the application scopes of this invention.

  The ophthalmic microscope of the present invention is an ophthalmic microscope that enables correction of residual aberrations, has aberrations that are close to left and right, and a focus difference, and is suitable for binocular vision, and has a small aperture objective lens Since an OCT apparatus and another optical system can be easily installed, it can be used in the optical equipment industry and the medical equipment related industry.

DESCRIPTION OF SYMBOLS 1 Ophthalmic microscope 2 Subject 300 Illumination optical system 301 Optical fiber 302 Emission light stop 303 Condenser lens 304 Illumination field stop 305 Collimate lens 306 Reflection mirror 400 Observation optical system 400L Left-eye observation optical system 400R Right-eye observation optical System 401 Objective lens 401a First lens 401b Optical element 401c for changing the direction of the optical axis Second lens 402 Zoom lens 402a, 402b, 402c Zoom lens 403 Beam splitter 404 Imaging lens 405 Image erecting prism 406 Eye width Adjustment prism 407 Field stop 408 Eyepiece 500 OCT optical system 501 Optical fiber 502 Collimate lens 503 Illumination field stop 504a, 504b Scanner 505 Relay optical system 506 First lens group 507 Second lens group 508 Reflecting mirror 50 OCT objective lens 6 Ophthalmic microscope body 8 Eye 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 Collimator 1008 Optical path length correction member 1009 Dispersion compensation Member 1010 Corner cube 1011 Collimator 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 Television camera 1102a Imaging element 12 Control unit 13 Display units 14, 14 'Pre-lens 15 Support column 16 Arm 17 XY fine movement device 18 User's microscope 19 Assistant's microscope 20 Pre-lens position adjustment mechanism 2001 Support bracket 2002 Rotating screw 2003 Movable plate 2004 Connection arm 2005 Fine adjustment knob 2006 Motor 21 Foot switch 22 Lens barrel 23 Holding arm 24 Holding plate 25 Tag detector 26 Fixed bracket 27 Inverter section 28 Switching lever A-401 Optical axis A-402 of objective lens Optical axis A-401a of variable magnification lens Optical axis A-401c of first lens Optical axis F1 of second lens Focus of objective lens Distances F2, F2 ′ Focal lengths H1, H1 ′ of the front lens Distances H2, H2 ′, H2 ″ between the objective lens and the front lens O-300 between the objective lens and the eye to be inspected Light of the illumination optical system Axis O-400 Optical axis of observation optical system O-400L Optical axis of observation optical system for left eye O-400R Observation optical system for right eye Axis O-500 Optical axis P-300 of OCT optical system Optical path P-400L of illumination optical system Optical path P-400R of observation optical system for left eye Optical path P-400SL of observation optical system for right eye Left eye of sub-observation optical system Optical path for the right eye P-400SR Optical path for the right eye of the sub-observation optical system P-500 Optical path of the OCT optical system Q400L Focus position of the left eye observation optical system Q400R Focus position of the right eye observation optical system V400L Image for the left eye V400R Right-eye image L0 Light output from the OCT light source unit Interference light LS Measurement light LR Reference light U0 Front focal position

Claims (6)

An illumination optical system for illuminating the eye to be examined, 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 illuminated by the illumination optical system, and optical coherence tomography An OCT optical system having an optical path of measurement light and an optical path of reference light for inspecting the eye to be examined, and a front lens detachable on the optical path between the eye to be examined and the objective lens In the microscope,
In the ophthalmic microscope, the optical axis of the left-eye observation optical system and the optical axis of the right-eye observation optical system are substantially parallel,
The left-eye observation optical system and the right-eye observation optical system each have an objective lens,
The objective lens comprises a lens group having at least a first lens, an optical element that changes the direction of the optical axis, and a second lens;
By the objective lens, 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 are changed to intersect with each other on the eye side to be examined,
The OCT optical system in which the OCT optical system is disposed in a region between the left-eye observation optical system and the right-eye observation optical system and transmits the optical axis of the OCT optical system separately from the objective lens Have
When the front lens is inserted on the optical path between the eye to be examined and the objective lens, the optical axis of the observation optical system and the optical axis of the OCT optical system are transmitted through the front lens,
Depending on the focal length of the front lens inserted on the optical path between the eye to be examined and the objective lens, the following 1) or 2) distance automatically changes,
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 examined and the objective lens When this is done, the length of the optical path of the reference light of the OCT optical system automatically changes according to the focal length of the front lens. A lens discriminating mechanism for obtaining information on the focal length of the front lens inserted on the optical path between the eye to be examined 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 ophthalmic microscope according to claim 1, further comprising a control mechanism that controls a position adjustment mechanism based on information on a focal length of the front lens acquired by the lens determination mechanism.   The ophthalmic microscope according to claim 1, wherein the optical element that changes 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 negative power, and the second lens is a convex lens having positive power. microscope. In the objective lens, the first lens, the optical element that changes the orientation of the optical axis, and the second lens are arranged in this order from the eye side to be examined.
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 a direction intersecting each other on the eye side to be examined. The ophthalmic microscope according to claim 1, wherein the ophthalmic microscope is characterized in that: In the objective lens, the first lens, the optical element that changes the orientation of the optical axis, and the second lens are arranged in this order from the eye side to be examined.
The optical axis of the second lens of the observation optical system for the left eye and the optical axis of the second lens of the observation optical system for the right eye are inclined in directions away from each other on the eye side to be examined. The ophthalmic microscope according to claim 1, wherein the ophthalmic microscope is characterized.