JP2018196676A - Ophthalmologic microscope - Google Patents

Abstract

To provide an ophthalmologic microscope which is suitable for binocular vision and allows for easy installation of another optical system.SOLUTION: In an ophthalmologic microscope 1, 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 parallel to each other, and an objective lens 401 included in each of the left and right observation optical systems comprises a lens group which has at least a first lens 401a, an optical element 401b for changing orientation of the optical axis, and a second lens 401c. The ophthalmologic microscope also includes an SLO optical system 1500 which allows the orientations of the left and right observation optical systems to be changed by the objective lens 401 into directions crossing each other at a side of subject eyes so that beams are guided to the subject eyes approximately coaxially with an optical axis O-500 of an OCT optical system.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 an OCT optical system 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.

  By the way, as an apparatus for observing the eye to be examined, there is an SLO (Scanning Laser Ophthalmoscope) that irradiates the eye with a laser beam and detects the reflected light, but there is also an apparatus that combines SLO and OCT. It has been developed (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 Laying-Open No. 2015-221091

  As schematically shown in FIG. 10 (A), the Galileo stereo microscope employed in the conventional ophthalmic microscope system includes an optical axis (O400L) of the left-eye observation optical system and an observation optical system for the right eye. 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. 10B, 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 occurs 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. 11A, 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. 11B, 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 also 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. 11A, 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. 11C, there is a problem in 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 an objective lens can be made small in diameter and an OCT optical system 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 OCT optical system can be easily installed by reducing the diameter of the objective lens. 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. Furthermore, the present inventors have found that by providing an SLO optical system that guides a light beam substantially coaxial with the optical axis of the OCT optical system to the eye to be examined, the position of the eye to be scanned scanned by the OCT optical system can be observed without deviation, The present invention has been completed. 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. An ophthalmic microscope comprising: a system; and an OCT optical system that scans measurement light for inspecting the eye by optical coherence tomography.
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,
It further includes an SLO optical system that scans light rays that are visible light, near infrared light, or infrared light, and guides the light to the eye to be inspected so as to be substantially coaxial with the optical axis of the OCT optical system. The present invention relates to an ophthalmic microscope characterized in that a portion of the eye to be examined scanned by an OCT optical system can be observed.
(2) The ophthalmic microscope of the present invention preferably includes a deflection optical element that scans in common the measurement light of the OCT optical system and the light beam of the SLO optical system.
(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 an OCT optical system can be easily installed. Furthermore, according to the present invention, the SLO optical system that guides the light beam substantially coaxial with the optical axis of the OCT optical system to the eye to be inspected, thereby observing the eye to be inspected without deviation from the image obtained by the OCT optical system. A possible ophthalmic microscope is provided.

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 the arrangement | positioning of the lens in the periphery of the objective lens, and arrangement | positioning of an optical path in the ophthalmic microscope of the 1st Embodiment of this invention. 4A shows the arrangement of lenses around the objective lens, and FIG. 4B shows the arrangement of optical paths around the objective lens. 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. It is drawing which shows typically the display part which displays the OCT image and SLO image which were acquired with the ophthalmic microscope of 1st Embodiment. 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 2nd Embodiment of the ophthalmic microscope of this invention, and the ophthalmic microscope of 3rd Embodiment. FIG. 7A shows the arrangement of the optical path around the objective lens of the ophthalmic microscope according to the second embodiment, and FIG. 7B shows the optical path around the objective lens of the ophthalmic microscope according to 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. 8A shows the configuration of the objective lens used in the ophthalmic microscope of the fourth embodiment, and FIG. 8B 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 the 5th Embodiment of this invention. FIG. 9A shows the configuration of the objective lens used in the ophthalmic microscope of the fifth embodiment, and FIG. 9B shows the direction of the optical axis of each lens constituting the objective lens. It is the schematic diagram which showed the image observed by the right and left eyes by the Galileo stereomicroscope which is a prior art, and the stereomicroscope. FIG. 10A 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. 10B shows the light of each lens in the Galileo stereomicroenvironment. FIG. 10C is a schematic diagram showing an image observed by the left and right eyes. It is the schematic diagram 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. 11A 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 microscopic environment, and FIG. 11B shows the light of each lens in the Greenough-type entity microenvironment. It is a schematic diagram which shows an axis | shaft, FIG.11 (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 The present invention relates to an ophthalmic microscope including an observation optical system having an observation optical system and an OCT optical system that scans measurement light for inspecting an eye to be examined by optical coherence tomography.
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. Moreover, 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 the 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.
Here, since 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 intersect on the eye side, they are not coaxial. Accordingly, the optical axis of the OCT optical system cannot be simultaneously coaxial with both the optical axis of the left-eye observation optical system and the optical axis of the right-eye observation optical system. For this reason, a shift occurs between an elephant observed by the observation optical system and an elephant obtained by the OCT optical system, and accurate alignment becomes difficult.
However, the ophthalmic microscope of the present invention further includes an SLO optical system that scans light rays that are visible light, near infrared light, or infrared light, and guides the light to the eye to be examined so as to be substantially coaxial with the optical axis of the OCT optical system. Have. With this SLO optical system, the eye to be examined can be observed without being deviated from the image obtained by the OCT optical system. For example, the shape of the fundus surface is imaged by the SLO optical system, and this is displayed on a part of the display unit (display), and the tomographic image obtained by the OCT optical system is superimposed or displayed in correspondence with the image. By displaying the image on the other part, it is possible for the observer to accurately grasp which part of the fundus surface the tomographic image corresponds to.

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 or iris, a corner, a vitreous body, a crystalline lens, or a ciliary body, and a retina in the posterior segment. Or choroid or vitreous. 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 can have a function as another ophthalmic apparatus in addition to a function as a microscope for magnifying and observing an eye to be examined. Examples of functions as other ophthalmic apparatuses include laser treatment, axial length measurement, refractive power measurement, and higher-order aberration measurement in addition to OCT. Other ophthalmologic apparatuses have an arbitrary configuration capable of performing examination, measurement, and imaging of an 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.
The “observation optical system” of the present invention may be one in which an observer can directly observe the subject's eye through an eyepiece lens or the like, and can be observed by receiving light with an imaging device or the like and imaging it. It may be provided or may have both functions.

  In the present invention, optical elements used in the “illumination optical system” or “observation optical system” are not limited to these, but examples include lenses, prisms, mirrors, optical filters, diaphragms, and diffraction gratings. 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, “objective lens” and “OCT objective lens” refer 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.

As the “light ray that is visible light, near infrared ray, or infrared ray” used in the SLO optical system of the ophthalmic microscope of the present invention, any light ray that includes wavelengths in the visible region, near infrared region, or infrared region can be used. Although it may be a light beam, it is preferably a highly directional light beam. More preferably, a laser beam is used.
In addition, the SLO optical system is “substantially coaxial with the optical axis of the OCT optical system” when the direction of each optical axis is substantially the same in the main region between the objective lens of the ophthalmic microscope and the eye to be examined. Well, there may be some deviation. Here, since both the optical path of the OCT optical system and the optical path of the SLO optical system are scanned, the direction of the light vibrates, but it is sufficient that the optical axis of the optical system at the center is substantially coaxial. Even when there is a slight deviation in the direction of the optical axis, it may be less than 6 °, more preferably less than 4 °, and even more preferably less than 1 °.

Although the ophthalmic microscope of the present invention has an OCT optical system and an SLO optical system, it is preferable that a part of the OCT optical system and the SLO optical system be a shared optical system from the viewpoint of downsizing the apparatus. . In particular, it is preferable to share the deflection optical element that scans the measurement light of the OCT optical system and the light beam of the SLO optical system.
When a part of the optical system is shared, the optical axis of the OCT optical system and the optical axis of the SLO optical system are substantially coaxial on the eye side, and the measurement light of the OCT optical system and the SLO optical system are on the detection system side. It is preferable to separate the light beam. In this case, the measurement light and the light beam can be separated by, for example, a dichroic mirror, an optical filter, or the like using characteristics such as the wavelength of light and deflection.

When the measurement light of the OCT optical system and the light beam of the SLO optical system are merged and scanned by the same deflecting optical element, the scanning range of the OCT optical system and the scanning range of the SLO optical system are the same. This makes it easier to align the images of both.
The deflection optical element shared by the OCT optical system and the SLO optical system may be any optical element that can scan the light by changing the direction of the light. For example, but not limited to these, an optical element having a reflective portion whose direction changes, such as a galvano mirror, a polygon mirror, a rotating mirror, a MEMS (Micro Electro Mechanical Systems) mirror, a deflection prism scanner, An optical element that can change the direction of light by an electric field, acoustooptic effect, or the like, such as an AO element, can be used.

2. First Embodiment Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.
FIGS. 1-6 is drawing which shows typically 1st Embodiment which is an example of the ophthalmic microscope of this invention. 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. 3 is a drawing schematically showing the optical configuration of the OCT unit, FIG. 4 is a cross-sectional view schematically showing the arrangement of lenses and optical paths around the objective lens, and FIG. It is a front view which shows typically the optical structure of an objective lens. FIG. 6 is a schematic diagram illustrating a display unit that displays an OCT image and an SLO image.

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. A system, an OCT optical system (500), and an SLO optical system (1500).
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), the SLO optical system (1500), and the illumination optical system (300) are for ophthalmic use indicated by a one-dot chain line. Housed in the microscope body (6).

  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 illumination light 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 collimating lens (305) toward the eye to be examined (8). The reflected light passes through the illumination objective lens (7) and is irradiated to the eye to be examined (8).
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.
The light receiving surface of the image sensor (1102a) is disposed at a position optically conjugate with the front focal position (U0) of the objective lens (401).
The beam splitter and the imaging optical system may be in both the left and right observation optical systems. A three-dimensional image can be obtained by acquiring images with parallax using the left and right imaging elements.
The TV camera image can be used for tracking the OCT observation site based on the acquired signal and image as well as the image of the observation site. If the subject's eye moves during the OCT scan due to fixation eye movement or surgical operation of the subject's eye, the tomographic image obtained by OCT will shift, but the movement of the fundus will be based on the image obtained by the TV camera. By detecting and scanning the OCT optical system in accordance with the movement of the fundus, it is possible to obtain an OCT tomographic image without deviation.

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 retina of the fundus, the front lens (14) is placed on the optical axes O-400L, O-400R, and O-500 in front of the eye of the eye to be inspected by moving means (not shown). Inserted. In this case, the front focal position (U0) of the objective lens (401) is conjugate with the retina (8a) of the fundus.
When observing the anterior segment of the cornea, iris, etc., the front lens is detached from the front of the subject's eye and the front focal position (U0) is aligned with the anterior segment.

  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. A system (505), a first lens group (506), a reflecting mirror (508), a second lens group (507), and an OCT objective lens (509) are included.

  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 includes collimating lens (502), illumination field stop (503), dichroic mirror (1501), scanner (504a, 504b), relay optical system (505), first lens group (506), reflection mirror ( 508), the second lens group (507), and the OCT objective lens (509), the test eye (8) is irradiated, and the return light of the measurement light reflected and scattered by the tissue of the test eye (8) is The light travels in the opposite direction 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).
The dichroic mirror (1501) is composed of a reflecting member that transmits the measurement light of the OCT optical system (500) without reflecting it.

  The scanners (504a, 504b) in the OCT optical system are deflection optical elements that deflect the direction of the measurement light that has been converted into a parallel light beam by the collimator lens (502) in a two-dimensional manner. The scanner includes a first scanner (504a) having a reflective surface that can be rotated about a first axis, and a second scanner (504b) having a reflective surface that can be rotated about a second axis perpendicular to the first axis. ) Including galvano mirror. A relay optical system (505) is provided between the first scanner (504a) and the second scanner (504b). When the distance between the first scanner (504a) and the second scanner (504b) is shortened, the relay optical system (505) may not be provided.

The first lens group (506) includes one or more lenses, and the second lens group (507) also includes one or more lenses. A reflection mirror (508) between the first lens group (506) and the second lens group (507) changes the direction of light toward the eye to be examined.
Further, an OCT objective lens (509) is provided on the side close to the eye to be examined (8). The OCT objective lens (509) is configured to be movable along the optical axis, and the focus of the OCT optical system can be adjusted by controlling the position of the OT objective lens. Thereby, the focus of the OCT optical system can be adjusted to a position different from the focus of the observation optical system.
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 objective lens of the OCT optical system can be reduced.

As shown in FIG. 1, the ophthalmic microscope (1) of the present invention further includes an SLO optical system (1500). The SLO optical system (1500) includes an SLO light source (16), an optical fiber (1502), a collimating lens (1503), an illumination field stop (1504), a dichroic mirror (1501), a half mirror (1505), and an optical stop (1506). , A condenser lens (1507), a reflected light detector (1508), and an image creation unit (1509).
The SLO light source (16) is provided outside the ophthalmic microscope main body (6), but one end of the optical fiber (1502) is connected thereto, thereby being connected to the ophthalmic microscope main body (6). . The light beam generated by the SLO light source (16) is emitted from the other end of the optical fiber (1502). The emitted light passes through the collimating lens (1503) and the illumination field stop (1504), is reflected by the half mirror (1505), is further reflected by the dichroic mirror (1501), and is measured by the OCT optical system (500). Merges coaxially with light.

As shown in FIG. 1, the combined light beam of the SLO optical system (1500) is two-dimensionally scanned by the optical scanners (504a, 504b) in the same manner as the measurement light of the OCT optical system (500). By using the optical scanner (504a, 504b) that requires a complicated mechanism in common for the OCT optical system (500) and the SLO optical system (1500), the apparatus can be reduced in size and cost.
In the ophthalmic microscope of the present invention, separate optical scanners may be provided for each of the OCT optical system and the SLO optical system, and the OCT optical system and the SLO optical system may be scanned independently. In this case, it is possible to simultaneously scan different parts of the surface to be observed.
The light beams of the SLO optical system (1500) scanned by the optical scanner (504a, 504b) are relay optical system (505), first lens group (506), reflection mirror (508), second lens group (507), The eye (8) is irradiated via the OCT objective lens (509) or the like. Here, the optical axis (O-500) of the SLO optical system guided to the eye to be examined (8) is coaxial with the optical axis (O-500) of the OCT optical system. Then, the return light of the light reflected / scattered by the tissue of the eye to be examined (8) travels in the opposite direction in the same path, is reflected by the dichroic mirror (1501), passes through the half mirror (1505), and is optically stopped. (1506), the light is detected by the reflected light detector (1508) via the condenser lens (1507). The detected signal is converted into an image by the image creation unit (1509).

As shown in FIG. 1, the dichroic mirror (1501) transmits the measurement light of the OCT optical system (500) and reflects the light beam of the SLO optical system (1500). Thereby, the measurement light of the OCT optical system (500) and the light beam of the SLO optical system (1500) can be merged and separated.
The half mirror (1505) reflects a part of the light beam of the SLO optical system (1500) and transmits a part thereof. The light source side and the light receiving side of the SLO optical system (1500) can be separated by the half mirror (1505).
The optical aperture (1506) is conjugate with the front focal position (U0) of the objective lens (2), and the condenser lens (1507) collects the light beam reflected and scattered by the eye to be examined (8).

The reflected light detector (1508) has a light detecting element for detecting a weak light beam reflected and scattered by the eye to be examined (8), and is composed of, for example, an APD (avalanche photodiode) or a photomultiplier tube. ing. The detection signal from the reflected light detector (1508) is sent to the image creation unit (1509). The light from the SLO light source (16) is irradiated to the eye (8) while scanning with the optical scanner (504a, 504b), and the light reflected and scattered by the eye (8) is detected by the reflected light detector (1508). By doing so, scan data of the eye to be examined (8) is obtained. The image creation unit (1509) creates an image of the eye to be examined (8) based on the scan data. This image is sent to the display for display, whereby the morphology of the tissue of the eye to be examined can be observed.
It is also possible to track the movement of the test site during OCT scanning based on signals and images obtained by SLO. By tracking, it is possible to correct a fixation fine movement of the eye to be inspected during scanning by OCT and a shift of an observation site due to a surgical operation.

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.
The OCT may be other types of OCT such as a spectral domain type OCT in addition to the Fourier domain type OCT exemplified below.
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 arithmetic 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 dichroic mirror (1501), a scanner (504a, 504b), a relay optical system (505), The eye (8) is irradiated via the one lens group (506), the reflection mirror (508), the second lens group (507), 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 arithmetic control unit (12). The arithmetic control unit (12), for example, 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). To do. The arithmetic 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 lens arrangement and optical path arrangement around the objective lens in the ophthalmic microscope according to the first embodiment. 4A shows the arrangement of lenses around the objective lens, and FIG. 4B shows the arrangement of optical paths around the objective lens.
As shown in FIG. 4A, an illumination objective lens (7) is provided in the lens barrel of the ophthalmic microscope main body (6). The illumination objective lens (7) is provided with three through holes (7a, 7b, 7c), of which two through holes (7a, 7c) are provided with a first lens (401a). Yes.

As shown in FIG. 4B, the optical path of the left-eye observation optical system (P-400L) and the optical path of the right-eye observation optical system (P-400R) in the barrel of the ophthalmic microscope main body (6). ), The optical path (P-300) of the illumination optical system, and the optical path (P-500) of the OCT optical system. Among these, the optical path (P-400L) of the observation optical system for the left eye is transmitted through the first lens (401a) in the through hole (7c) of the illumination objective lens (7) shown in FIG. The optical path (P-400R) of the right-eye observation optical system passes through the first lens (401a) in the through hole (7a) of the illumination objective lens (7) shown in FIG. It is transparent. The optical path (P-500) of the OCT optical system passes through the through hole (7b) of the illumination objective lens (7) shown in FIG.
In the ophthalmic microscope according to the first embodiment of the present invention, since each optical system has its own objective lens, the optical path of each optical system 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).

FIG. 6 is a schematic diagram of a display unit that displays an OCT image and an SLO image acquired by the ophthalmic microscope according to the first embodiment.
As shown in FIG. 6, the display unit (13) has a display screen (1301). The display screen (1301) is provided with six image display units (1302-1307). These image display units are a first longitudinal section image display section (1302), a transverse section image display section (1303), a processed image display section (1304), a front image display section (1305), and a second longitudinal section, respectively. A plane image display unit (1306) and a surgical guide image display unit (1307).
The front image display unit (1305) displays the fundus surface image acquired by the SLO optical system. The first vertical cross-sectional image display unit (1302), the cross-sectional image display unit (1303), and the second The tomographic image of the fundus acquired by the OCT optical system is displayed on the longitudinal section image display unit (1306). In the processed image display unit (1304), an image (processed image) obtained by performing a predetermined processing on the image displayed in the other image display unit, for example, angiography (Angiography), projection (Projection, fundus tomographic image), an image for detecting a lesion such as diabetic retinopathy is displayed. In FIG. 6, an image of the fundus surface obtained by the SLO optical system is displayed on the processed image display unit (1304), and the lesion site is colored and displayed. Here, the location of the lesion is identified by image analysis of a tomographic image obtained by OCT.

As shown in FIG. 6, in the front image display unit (1305), an observation image of the fundus oculi surface is shown. The horizontal direction is the x axis and the vertical direction is the y axis. Then, the cross-sectional image display unit (1303) displays a tomographic image of the fundus xy cross section.
The first longitudinal section image display unit (1302) and the second longitudinal section image display unit (1306) include a fundus along two z-direction sections indicated by dotted lines in the front image display unit (1305). The tomographic image of is displayed. The tomographic image of the yz section is displayed on the first longitudinal section image display unit (1302), and the tomographic image of the xz section is displayed on the second longitudinal section image display unit (1306).
The surgery guide image display unit (1307) can display, for example, an image obtained by superimposing a portion that must be operated on an image obtained before surgery, and combining it.

  Here, in the ophthalmic microscope according to the first embodiment, since the optical axis of the OCT optical system and the optical axis of the SLO optical system are coaxial, an observation image of the fundus surface acquired by the SLO optical system and There is no positional deviation from the tomographic image of the fundus acquired by the OCT optical system. For this reason, there is no positional deviation between the observation image of the fundus surface displayed on the front image display unit (1305) and the tomographic image on the xy cross section displayed on the cross sectional image display unit (1303), and accurate alignment is achieved. It becomes possible. Also, two cross sections indicated by dotted lines in the front image display unit (1305), a tomogram of the yz cross section displayed on the first vertical cross section image display unit (1302), and a second vertical cross section image display unit (1306) There is no misalignment with the tomographic image of the xz cross section displayed in FIG.

3. Second and Third Embodiments Next, examples of other embodiments of the present invention will be described with reference to the drawings.
FIG. 7 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 sectional drawing.
FIG. 7A shows the arrangement of the optical path around the objective lens of the ophthalmic microscope according to the second embodiment, and FIG. 7B shows the optical path around the objective lens of the ophthalmic microscope according to the third embodiment. The arrangement of

As shown in FIG. 7A, in the ophthalmic microscope according to the second embodiment, the optical path (P-400L) of the left-eye observation optical system is provided 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.
In the ophthalmic microscope of the present invention, since the observation optical system and the OCT optical system have their own objective lenses, it is possible to arrange the optical paths of such many optical systems independently.

  As shown in FIG. 7B, 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.

4). 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 and orientation of the optical axis 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 tilted in a direction that intersects with the eye to be examined. It is preferable. 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, the problem that the peripheral focus difference is reversed between the left and right eye images as shown in FIG. 11 can be greatly improved.

5. Fourth Embodiment FIG. 8 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. 8A shows the configuration of the objective lens used in the ophthalmic microscope of the fourth embodiment, and FIG. 8B shows the direction of the optical axis of each lens constituting the objective lens.

  As shown in FIG. 8A, 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. 8B, the optical axes (A-401c) of the second lens are inclined in directions away from each other on the eye side.
By adopting such a configuration, the problem that the peripheral focus difference is reversed between the left and right eye images as shown in FIG. 11 can be greatly improved.

6). Fifth Embodiment FIG. 9 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. 9A shows the configuration of the objective lens used in the ophthalmic microscope of the fifth embodiment, and FIG. 9B shows the direction of the optical axis of each lens constituting the objective lens.

  As shown in FIGS. 9A and 9B, the objective lens (401) used in the ophthalmic microscope of the fifth embodiment has a wedge prism (401b), negative power from the eye side to be examined. 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 the OCT 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 main body 7 Illumination objective lenses 7a, 7b, 7c Through hole 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 Connection Image lens 1102 Television camera 1102a Image sensor 12 Arithmetic control unit 13 Display unit 1301 Display screen 13 02 First longitudinal section image display section 1303 Cross section image display section 1304 Processed image display section 1305 Front image display section 1306 Second longitudinal section image display section 1307 Surgery guide image display section 14 Pre-lens 1500 SLO optical system 1501 Dichroic Mirror 1502 Optical fiber 1503 Collimator lens 1504 Illumination field stop 1505 Half mirror 1506 Optical stop 1507 Condensing lens 1508 Reflected light detector 1509 Image creation unit A-401 Optical axis A-402 of objective lens Optical axis A-401a of variable magnification lens Optical axis A-401c of the first lens Optical axis O-300 of the second lens Optical axis O-400 of the illumination optical system Optical axis O-400L of the observation optical system Optical axis O-400R of the observation optical system for the left eye Optical axis of observation optical system for right eye O-500 Optical axis of OCT optical system, optical axis P of SLO optical system 300 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 Optical path P-400SR for left eye of sub observation optical system Right of sub observation optical system Optical path for the eye P-500 Optical path for the OCT optical system, optical path for the SLO optical system Q400L Focus position Q400R for the left-eye observation optical system Focus position V400L for the right-eye observation optical system Image for the left eye V400R Image for the right eye Light LC output from L0 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 In an ophthalmic microscope provided with an OCT optical system that scans measurement light for inspecting the eye to be examined by
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,
It further includes an SLO optical system that scans light rays that are visible light, near infrared light, or infrared light, and guides the light to the eye to be inspected so as to be substantially coaxial with the optical axis of the OCT optical system. An ophthalmic microscope characterized in that an area including a portion of the eye to be examined scanned by an OCT optical system can be observed.   The ophthalmic microscope according to claim 1, further comprising a deflection optical element that scans the measurement light of the OCT optical system and the light of the SLO optical system in common.   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.