WO2015072419A1

WO2015072419A1 - Ophthalmic device and method for controlling same

Info

Publication number: WO2015072419A1
Application number: PCT/JP2014/079697
Authority: WO
Inventors: 内田　浩治
Original assignee: キヤノン株式会社
Priority date: 2013-11-14
Filing date: 2014-11-10
Publication date: 2015-05-21
Also published as: JP2015093160A

Abstract

Provided is a structure that can highly precisely perform the relative positioning of a subject eye and an ophthalmic device. Imaging is performed of the subject eye illuminated by a measurement light source, and the cornea reflection image reflected by the cornea of the subject eye (E) is extracted from the image obtained by the imaging. Also, it is determined (S103) whether or not an intraocular lens (IOL) is inserted in the subject eye on the basis of the cornea reflection, and the method for relative positioning of the ophthalmic device and the subject eye is altered (S104; S105 and S106) in accordance with the determination results.

Description

Ophthalmic apparatus and control method thereof

The present invention relates to an ophthalmologic apparatus for measuring an eye to be examined and a control method thereof.

Conventionally, an ophthalmologic apparatus for measuring an eye to be examined has been used.

Alignment of the ophthalmologic apparatus with respect to the eye to be examined is performed based on information on a position detection index extracted from an image obtained by an image sensor. At this time, it is necessary to separate an index image to be used for the above-described alignment from an inappropriate image such as noise or ghost in the image obtained by the image sensor.

Further, in recent years, many elderly people have performed cataract surgery, and an eye to be examined (hereinafter referred to as “IOL” if necessary) into an intraocular lens (hereinafter referred to as “IOL”) that becomes a pseudo crystalline lens. (Hereinafter referred to as “IOL insertion eyes”). In addition, the types of IOLs are increasing year by year.

As a conventional technique, for example, the following Patent Document 1 proposes a technique for easily and accurately determining the suitability of a multifocal intraocular lens. Specifically, in the ophthalmologic apparatus described in Patent Document 1 below, a technique is disclosed that makes it possible to compare the acquired size information of the multifocal intraocular lens and the size of the pupil detected by the pupil detection means. .

JP 2011-229842 A

However, conventionally, when the ophthalmologic apparatus is positioned with respect to the eye to be examined in a situation where a wide variety of IOLs are increasing, the projected light flux of the alignment index is reflected by the IOL, and a ghost is generated. May be misdetected and positioning may be difficult.

The present invention has been made in view of such problems, and an object of the present invention is to provide a mechanism that can perform relative alignment between an eye to be examined and an ophthalmic apparatus with high accuracy.

An ophthalmologic apparatus of the present invention is an ophthalmologic apparatus that measures an eye to be examined, an illuminating means that illuminates the eye to be examined, an imaging means that images the eye to be examined illuminated by the illuminating means, and the imaging means Extracting means for extracting a cornea reflection image reflected by the cornea of the eye to be examined from an image obtained by imaging by the method, and determining whether an intraocular lens is inserted in the eye based on the cornea reflection image And a positioning unit that changes a relative positioning method between the eye to be examined and the ophthalmologic apparatus according to a result of the determination unit.

The present invention also includes a control method using the above-described ophthalmologic apparatus.

According to the present invention, the relative alignment between the eye to be examined and the ophthalmic apparatus can be performed with high accuracy.

It is an external view which shows an example of schematic structure of the ophthalmologic apparatus which concerns on embodiment of this invention. It is a schematic diagram which shows an example of arrangement | positioning of the optical system containing the eye refractive power measurement optical system inside the measurement part shown in FIG. It is a figure which shows an example of the structure of the alignment prism stop shown in FIG. It is a schematic diagram which shows an example of arrangement | positioning of the optical system containing the cornea curvature radius measurement optical system inside the measurement part shown in FIG. It is a figure which shows embodiment of this invention and shows an example of the cross section of the eye to be examined. It is a figure which shows an example of the image obtained with the image pick-up element shown in FIG. It is a figure which shows embodiment of this invention and shows an example of the image formation state of the bright spot image in case the eye to be examined is an IOL insertion eye. It is a figure which shows embodiment of this invention and shows an example of the reflective ghost image by IOL of the alignment projection light beam. It is a figure which shows embodiment of this invention and shows an example of the imaging state of the bright spot image of the anterior ocular illumination light source in case the eye to be examined is an IOL insertion eye. It is a figure which shows embodiment of this invention and shows an example of the imaging state of the bright spot image of the anterior ocular illumination light source in case the eye to be examined is an IOL insertion eye. It is a block diagram which shows an example of the system configuration | structure of the ophthalmologic apparatus which concerns on embodiment of this invention. It is a flowchart which shows an example of the process sequence in the control method of the ophthalmologic apparatus which concerns on embodiment of this invention. It is a figure for demonstrating the pupil detection process of step S105 shown in FIG. It is a flowchart which shows an example of the detailed process sequence in the IOL insertion eye determination process of step S103 shown in FIG. It is a figure for demonstrating the cornea reflection image extraction process of step S201 shown in FIG. It is a figure for demonstrating the cornea reflection image extraction process of step S204 shown in FIG. 13 is a flowchart illustrating an example of a processing procedure according to a modified example after it is determined that the eye to be examined is an IOL insertion eye in Step S103 illustrated in FIG. 12 (S103 / NO). It is a figure for demonstrating the corneal ring image detection process of step S301 shown in FIG.

Hereinafter, embodiments (embodiments) for carrying out the present invention will be described with reference to the drawings. In the following embodiments of the present invention, an ophthalmologic apparatus that measures eye refractive power and corneal curvature radius will be described as an example of an ophthalmologic apparatus according to the present invention.

FIG. 1 is an external view showing an example of a schematic configuration of an ophthalmologic apparatus according to an embodiment of the present invention.

The ophthalmologic apparatus shown in FIG. 1 is an apparatus that performs measurement of the eye E of the subject H (specifically, measurement of the eye refractive power and the corneal curvature radius of the eye E in the present embodiment). The ophthalmologic apparatus shown in FIG. 1 has a base portion 100 having a chin rest 112 that receives the jaw of a subject H, a drive unit 120 and an operation unit 130 provided on the base unit 100, and is mounted on the drive unit 120. The measuring unit 110 is configured.

(Base part 100)
The base portion 100 is provided with an eye position fixing mechanism for fixing the position of the eye E of the subject H. The eye position fixing mechanism to be examined has a chin rest 112, a chin rest motor 113, and a face rest frame (not shown). When the subject H measures the eye E, the subject H places his / her chin on the chin rest 112 and pushes the forehead to a forehead receiving portion of a face receiving frame (not shown) fixed to the base portion 100. By applying, the face of the subject H can be fixed, and the position of the eye E can be fixed. The chin rest 112 can be adjusted in the Y-axis direction by the chin rest motor 113 according to the size of the face of the subject H.

(Driver 120)
The drive unit 120 has a drive mechanism corresponding to each axis in order to move (drive) the measurement unit 110 in the XYZ directions. Hereinafter, the drive mechanism in each axial direction will be described.

<Drive mechanism in X-axis direction (X direction)>
The frame 102 is movable in the left-right direction (hereinafter referred to as “X-axis direction (X direction)”) with respect to the base unit 100 (or the subject H). The drive mechanism in the X-axis direction includes an X-axis motor 103 fixed on the base portion 100, a feed screw (not shown) connected to the output shaft of the X-axis motor 103, and the feed screw on the X-axis direction. And a nut (not shown) fixed to the frame 102. As the X-axis motor 103 rotates, the frame 102 moves in the X-axis direction via a feed screw (not shown) and a nut (not shown).

<Driving mechanism in the Y-axis direction (Y direction)>
The frame 106 is movable in the vertical direction (hereinafter referred to as “Y-axis direction (Y direction)”) with respect to the frame 102. The drive mechanism in the Y-axis direction is movable in the Y-axis direction on the Y-axis motor 104 fixed on the frame 102, the feed screw 105 connected to the output shaft of the Y-axis motor 104, and the feed screw 105. It has a nut 114 fixed to the frame 106. As the Y-axis motor 104 rotates, the frame 106 moves in the Y-axis direction via the feed screw 105 and the nut 114.

<Drive mechanism in the Z-axis direction (Z direction)>
The frame 107 is movable in the front-rear direction (hereinafter referred to as “Z-axis direction (Z direction)”) with respect to the frame 106. The drive mechanism in the Z-axis direction includes a Z-axis motor 108 fixed to the frame 107, a feed screw 109 connected to the output shaft of the Z-axis motor 108, and a movement on the feed screw 109 in the Z-axis direction. A nut 115 fixed to 106 is provided. As the Z-axis motor 108 rotates, the frame 107 moves in the Z-axis direction via the feed screw 109 and the nut 115.

(Measurement unit 110)
A measuring unit 110 is fixed on the frame 107.

The measurement unit 110 includes an optical system for performing inspection, observation, imaging, measurement, and the like of the eye E of the subject H. A light source unit 111 for performing automatic alignment and measurement of the eye E is provided on the subject H side of the measurement unit 110. Further, on the side opposite to the subject H side of the measuring unit 110, an LCD monitor 116, which is a display member for the examiner to observe the subject eye E and the like, is provided. The LCD monitor 116 can display measurement results and the like.

(Operation unit 130)
On the base unit 100, an operation unit 130 including a joystick 101 is provided. The joystick 101 is an operation member for aligning the measuring unit 110 with respect to the eye E. The examiner operates the joystick 101 to instruct the driving direction, driving amount, driving speed, etc. of the driving unit 120, etc., and aligns the position of the measuring unit 110 with the eye E to be examined and observed. , Take pictures, etc.

FIG. 2 is a schematic diagram showing an example of an arrangement of an optical system including an eye refractive power measurement optical system inside the measurement unit 110 shown in FIG.

On the optical path 01 from the measurement light source (eye refractive power measurement light source) 201 that irradiates light having a wavelength of about 880 nm to the eye E, a lens 202, a diaphragm 203 almost conjugate with the pupil Ep of the eye E, and a hole are provided. A mirror 204, a lens 205, and a dichroic mirror 206 that totally reflects visible light from the eye E side and partially reflects a light beam having a wavelength of about 880 nm are sequentially arranged.

Further, on the optical path 02 in the reflection direction of the perforated mirror 204, a stop 207 having an annular slit substantially conjugate with the pupil Ep of the eye E, a light beam spectroscopic prism 208, a lens 209, and an image sensor 210 are sequentially arranged. It is installed.

The optical system related to the optical path 01 and the optical path 02 described above is an eye refractive power measuring optical system.

Here, the light beam emitted from the measurement light source 201 is primarily focused in front of the lens 205 by the lens 202 while being focused by the diaphragm 203, and passes through the lens 205 and the dichroic mirror 206 to be inspected by the eye E. The center of the pupil Ep is projected. Then, the luminous flux forms an image on the fundus oculi Er, and the reflected light enters the lens 205 again through the center of the pupil Ep. The light beam incident on the lens 205 is reflected around the perforated mirror 204 after passing through the lens 205. This reflected light beam is pupil-separated by a stop 207 substantially conjugate with the pupil Ep of the eye E, and is projected as a ring image on the light receiving surface of the image sensor 210. At this time, if the eye E is a normal eye, this ring image becomes a predetermined circle, and the curvature of the circle is small for the myopic eye, and the curvature of the circle is large for the hyperopic eye. When the subject eye E has astigmatism, the ring image becomes an ellipse, and the angle formed by the horizontal axis and the major axis of the ellipse becomes the astigmatism axis angle. In the ophthalmologic apparatus according to the present embodiment, the eye refractive power is obtained based on the elliptic coefficient.

On the other hand, in the reflection direction of the dichroic mirror 206, a fixation target projecting optical system and an alignment light receiving optical system that shares anterior eye portion observation and alignment detection of the eye E are arranged.

On the optical path 03 of the fixation target projection optical system, a lens 211, a dichroic mirror 212, a lens 213, a folding mirror 214, a lens 215, a fixation target 216, and a fixation target light source 217 are sequentially arranged.

At the time of fixation fixation, the projected light flux of the fixed fixation target light source 217 illuminates the fixation target 216 from the back side, and the fundus Er of the eye E to be examined via the lens 215, the folding mirror 214, the lens 213, and the dichroic mirror 212. Projected on. Note that the lens 215 can be moved in the optical axis direction by a fixation guidance motor (not shown) in order to perform diopter guidance of the eye E and realize a cloud state.

Further, an alignment light receiving optical system is configured in the optical path 04 in the reflection direction of the dichroic mirror 212. On the optical path 04, an alignment prism diaphragm 223 driven by an alignment prism diaphragm insertion / extraction solenoid (not shown: 411 in FIG. 11), a lens 218, and a diaphragm 219 driven by a diaphragm insertion / extraction solenoid (not shown: 412 in FIG. 11). The image sensor 220 is sequentially arranged. By this alignment light receiving optical system, it is possible to observe the anterior segment of the eye E and to detect alignment.

FIG. 3 is a diagram showing an example of the structure of the alignment prism diaphragm 223 shown in FIG.

The alignment prism diaphragm 223 is provided with three

openings

223a, 223b, and 223c in a disk-shaped diaphragm plate. In addition,

alignment prisms

301a and 301b that transmit light beams only in the vicinity of a wavelength of 880 nm are attached to the lens 218 side of the

openings

223b and 223c at both ends, respectively.

Here, we return to the explanation of FIG. 2 again.

Anterior eye

illumination light sources

221a and 221b that irradiate light having a wavelength of about 780 nm are disposed obliquely in front of the anterior eye portion of the eye E to be examined. The light beam of the anterior segment image of the eye E illuminated by the anterior

illumination light sources

221a and 221b passes through the dichroic mirror 206, the lens 211, the dichroic mirror 212, and the central aperture 223a of the alignment prism diaphragm 223, and the image sensor 220. An image is formed on the light receiving sensor surface.

The light source for alignment detection is also used as the measurement light source 201 for measuring eye refractive power. At the time of alignment, a translucent diffusion plate 222 is inserted into the optical path 01 by a diffusion plate insertion / removal solenoid (not shown: 410 in FIG. 11). At this time, the position where the diffusion plate 222 is inserted is the primary image formation position by the lens (projection lens) 202 of the measurement light source 201 described above, and is inserted at the focal position of the lens 205. As a result, an image of the measurement light source 201 is once formed on the diffusion plate 222, which becomes a secondary light source and is projected from the lens 205 toward the eye E as a thick parallel light beam. This thick parallel light beam will be described in detail later as an alignment projection light beam.

FIG. 4 is a schematic diagram showing an example of the arrangement of the optical system including the corneal curvature radius measuring optical system inside the measuring unit 110 shown in FIG. In FIG. 4, the same reference numerals are given to the same components as those shown in FIG.

4, corneal curvature

radius light sources

224a and 224b for irradiating light having a wavelength of about 780 nm are disposed inside the anterior

illumination light sources

221a and 221b. The corneal curvature

radius light sources

224a and 224b irradiate the eye E with a diffused light beam through the

diffusion plates

225a and 225b, respectively. Here, in FIG. 4, only two corneal

curvature light sources

224a and 224b are shown, but actually, the corneal curvature light source is arranged in an annular shape (ring shape) around the optical path 01. The ring light source projects a ring-shaped light beam onto the eye E.

The ring-shaped light beam irradiated from this corneal curvature radius light source and reflected by the cornea Ec of the eye E is reflected by the dichroic mirror 206, passes through the lens 211, is reflected by the dichroic mirror 212, is converged by the lens 218, and is stopped. The image sensor 220 receives light as a ring image (corneal ring image) through the opening 219. At this time, the alignment prism diaphragm 223 is removed from the optical path 04. At this time, the light beams from the anterior

illumination light sources

221a and 221b and the corneal curvature

radius light sources

224a and 224b are directed to the image sensor 220, but the aperture 219 is disposed at a position where the light beams from the corneal curvature radius light sources converge. The luminous flux of the eye illumination light source is reduced and received. Then, in the ophthalmologic apparatus according to the present embodiment, the corneal curvature radius of the eye E is obtained using a known conversion formula based on the ring image received by the image sensor 220. At this time, if the eye E has corneal astigmatism, the ring image received by the image sensor 220 becomes an ellipse, and corneal astigmatism can also be measured.

Next, in the ophthalmologic apparatus for measuring the eye refractive power and the corneal curvature radius, the alignment detection using the alignment projection light will be described in detail.

FIG. 5 is a diagram illustrating an example of a cross section of the eye E according to the embodiment of the present invention.

In FIG. 5, the upper part of the paper is the nose side of the eye E, and the lower part of the paper is the ear side of the eye E. FIG. 5 shows a cornea Ec, a pupil Ep, and a lens El of the eye E. As shown in FIG. 4, the parallel light beam that is thick toward the eye E is refracted by the cornea Ec and forms a bright spot image P <b> 1 in the vicinity of about ½ of the radius of curvature. The imaged light flux is returned to the measurement optical system of the ophthalmologic apparatus, a part of which is reflected again by the dichroic mirror 206, is reflected by the dichroic mirror 212 through the lens 211, and the opening 223a of the alignment prism diaphragm 223. Then, the light passes through the

alignment prisms

301a and 301b, is converged by the lens 218, and forms an image on the image sensor 220.

In the center opening 223a of the alignment prism diaphragm 223 shown in FIG. 3, a light beam having a wavelength of 780 nm or more of the anterior eye

illumination light sources

221a and 221b passes. For this reason, the reflected light beam of the anterior segment image illuminated by the anterior

illumination light sources

221a and 221b follows the observation optical system in the same manner as the path of the reflected light beam of the cornea Ec, and passes through the opening 223a of the alignment prism diaphragm 223. The image is formed on the image sensor 220 by the lens 218. Further, the light beam transmitted through the alignment prism 301a is refracted downward, and the light beam transmitted through the alignment prism 301b is refracted upward.

FIG. 6 is a diagram showing an example of an image obtained by the image sensor 220 shown in FIG.

FIG. 6A shows an image in a case where the eye refractive power measurement optical system is properly aligned in the three-dimensional directions of up and down, left and right, and front and rear. As described above, the light beam is separated into three by the alignment prism diaphragm 223. In the case shown in FIG. 6A, the bright spot images P1 refracted in the vertical direction by the

alignment prisms

301a and 301b are vertically aligned. Are lined up.

Here, if there is a displacement in the working distance direction (Z direction), the upper and lower bright spot images are shifted in the left-right direction as shown in FIG.

When the measurement unit 110 is displaced in the left-right direction with respect to the eye E, the three bright spot images are shifted in the left-right direction together.

FIG. 6C shows an image when the measuring unit 110 is appropriate for the working distance direction with respect to the eye E, but is slightly shifted to the nose side. FIG. 6D shows an image when the measuring unit 110 is slightly shifted in the working distance direction with respect to the eye E and the left and right direction is also slightly shifted to the nose side.

If the subject eye E is a healthy eye, the position of the bright spot image P1 can be detected and the measuring unit 110 can be aligned with the subject eye E. For example, a cataract operation is performed, and the subject eye E inserts an IOL. In the case of an insertion eye, it is known that a ghost of a bright spot image for alignment occurs. The mechanism is as follows.

FIG. 7 shows an embodiment of the present invention, and is a diagram showing an example of an image formation state of a bright spot image when the eye E to be examined is an IOL insertion eye.

FIGS. 7A and 7B show reflection images of the eye E on the cornea Ec. Specifically, in FIG. 7A, only the lens El shown in FIG. 5 is replaced with the IOL, and the light beam refracted by the cornea Ec forms a bright spot image P1 in the vicinity of about ½ of the radius of curvature. FIG. 7B shows a case where the alignment is slightly shifted to the nose side, and the light beam refracted by the cornea Ec is slightly shifted to the nose side to form an image (P1 ′). However, in the case of the IOL, since the material is different from the original crystalline lens El, it is known from experience that more reflection components are generated on the front side and the rear side of the IOL than the crystalline lens El.

7 (c) and 7 (d) show only the light beam that has been totally reflected and transmitted and refracted on the front side of the IOL in FIG. 7 (a). Since the reflected light beam on the front side of the IOL becomes divergent light, the light beam returning to the dichroic mirror 206 of the measurement unit 110 is small and does not appear as a ghost. In FIG. 7C, the transmitted refraction component is imaged at the position P2, but since the position is far away from the cornea Ec and the pupil Ep of the eye E, the light flux returned to the measurement unit 110 is normally It is not reflected on the image sensor 220 at the working distance for alignment. FIG. 7 (d) shows a position shifted to the nose side, but the thick alignment projection light beam is partially kicked by the pupil Ep and an afterglow image is formed (P2 ′). Since the emitted light flux is further reduced, it is not reflected on the image sensor 220.

FIGS. 7 (e) and 7 (f) show only the light beam that has been totally reflected and transmitted and refracted on the rear surface side of the IOL. In FIG. 7E, a reflected image is formed near the apex of the cornea Ec (P3), and this is reflected on the image sensor 220. When the alignment is shifted to the nose side as shown in FIG. 7F, the reflected image is formed by shifting to the ear side (P3 '). When the image is further shifted to the nose side, the image is further shifted to the ear side, and the projected light beam is kicked to the pupil Ep, so that the bright spot image becomes distorted and becomes thin and appears on the image sensor 220.

FIG. 8 shows an embodiment of the present invention and is a diagram showing an example of a reflected ghost image by the IOL of the alignment projection light beam.

FIG. 8A shows an image shown on the image sensor 220 when aligned at an approximately appropriate position. FIG. 8 (a) shows a corneal reflection image P1 and a reflection ghost image P3 'based on the IOL. In this case, the reflected ghost image P3 'by the IOL often appears obliquely on the ear side or the lower part of the eye E to be examined because the IOL is slightly decentered or tilted.

FIG. 8B shows an image reflected on the image sensor 220 when the measuring unit 110 is shifted to the nose side of the eye E with respect to the eye E. In this case, the reflected ghost image P3 'by the IOL is separated from the cornea reflected image P1.

FIG. 8C shows an image reflected on the image sensor 220 when a part of the projected light beam is kicked by the pupil Ep. In this case, the reflected ghost image P3 'by the IOL appears in a distorted and bright spot image.

The generation of the reflected ghost image by the IOL when performing alignment with the alignment projection light beam has been described above. However, when performing wider alignment detection, alignment detection is performed using the cornea reflection images of the anterior

illumination light sources

221a and 221b. It is also known to do. In this case as well, a reflected ghost image is generated by the IOL.

FIG. 9 shows an embodiment of the present invention and is a diagram showing an example of an image formation state of bright spot images of the anterior

illumination light sources

221a and 221b when the eye E is an IOL insertion eye.

FIG. 9A shows a position state in which the eye E and the measuring unit 110 are substantially in the vertical and horizontal directions. In FIG. 9A, the light beam emitted from the anterior illumination light source 221a is transmitted and refracted by the cornea Ec of the eye E to form a bright spot image R1. At this time, a part of the transmitted and refracted light beam is reflected on the rear surface side of the IOL, but since the light source is located away from the measurement optical axis, most of the light beam is kicked by the pupil Ep. Then, a slight light beam is reflected on the rear side and imaged at the bright spot P4. Similarly, the light beam emitted from the anterior illumination light source 221b is also refracted and imaged by the cornea Ec of the eye E to be a bright spot image R2. At this time, the light beam emitted from the anterior illumination light source 221b and not kicked to the pupil Ep is reflected and imaged on the rear surface side of the IOL in the same manner as the anterior illumination light source 221a. The imaging position is symmetrical with respect to the bright spot P4 and the optical axis, but is omitted in FIG.

In this way, the image shown on the image sensor 220 in the state where the position of the measuring unit 110 in the vertical and horizontal directions is almost appropriate is as shown in FIG. Then, as shown in FIG. 9A, the IOL reflected ghost image by the anterior eye illumination light source is picked up only by the bright spot image R2 from the measurement unit 110 side by overlapping the bright spot P4 and the bright spot image R2. Reflected on element 220.

FIG. 10 shows an embodiment of the present invention, and is a diagram showing an example of an image formation state of bright spot images of the anterior

illumination light sources

221a and 221b when the eye E to be examined is an IOL insertion eye.

FIG. 10A shows a state in which the measurement unit 110 is shifted to the nose side with respect to the eye E to be examined. In FIG. 10A, when all the light beams emitted from the anterior illumination light source 221a are transmitted and refracted into the pupil Ep, they are reflected by the rear surface of the IOL and imaged at the position P4 '. Since this shifts to the optical axis as compared with FIG. 9A, as shown in FIG. 10B, a bright spot image P4 'is reflected in the imaging element 220 in the pupil Ep. Further, the light beam irradiated from the anterior illumination light source 221b is transmitted and refracted by the cornea Ec of the eye E, and almost all of the light beam is kicked by the pupil Ep and does not reach the rear surface of the IOL. As illustrated in FIG. 10B, the anterior eye illumination light source image R <b> 2 ′ is reflected on the image sensor 220 so as to overlap the iris of the eye E to be examined.

FIG. 11 is a block diagram showing an example of a system configuration of the ophthalmologic apparatus according to the embodiment of the present invention. In FIG. 11, the same reference numerals are given to the same configurations as those shown in FIGS. 1, 2, and 4.

The system control unit 401 controls the entire system of the ophthalmologic apparatus according to the present embodiment.

Input from the joystick 101 for positioning the measuring unit 110 with respect to the eye E is input to the system control unit 401 via the X, Z axis tilt angle input unit 402 and the Y axis encoder input unit. Is done. The measurement start switch 404 is arranged on the joystick 101 so as to input a measurement start signal to the system control unit 401. In addition, information from the operation panel 405, various position sensors 406, and left / right encoder input unit 407 is input to the system control unit 401.

An image signal is input to the system control unit 401 from the image pickup device 210 that is an image pickup unit, and the system control unit 401 extracts the above-described ring image and calculates a spherical power, an astigmatism power, an astigmatic axis angle, and the like. Similarly, an image signal from the image sensor 220 that is an imaging unit is also input to the system control unit 401, and the system control unit 401 similarly extracts a ring image and calculates a corneal curvature radius and the like.

Further, at the time of alignment, the system control unit 401 is configured to accept input of an anterior ocular segment image, an alignment bright spot, and the like from the anterior ocular

illumination light sources

221a and 221b. A real-time image at the time of alignment is displayed on the LCD monitor 116 via an image processing circuit (not shown) of the system control unit 401.

Further, the solenoid drive circuit 409 drives the diffusion plate insertion / extraction solenoid 410, the alignment prism diaphragm insertion / extraction solenoid 411, and the diaphragm insertion / extraction solenoid 412 based on a command from the system control unit 401. By these driving operations, the diffusion plate 222, the alignment prism diaphragm 223, and the diaphragm 219 are driven.

The light source driving circuit 413 is an illuminating unit that illuminates the eye E based on a command from the system control unit 401, and includes a measurement light source 201, anterior eye

illumination light sources

221a and 221b, a fixation target light source 217, and a corneal curvature. The

radial light sources

224a and 224b are respectively driven.

Further, the motor drive circuit 414 drives the chin rest motor 113, the X-axis motor 103, the Y-axis motor 104, and the Z-axis motor 108 based on a command from the system control unit 401.

Next, a method for controlling an ophthalmologic apparatus having such a configuration will be described.

FIG. 12 is a flowchart showing an example of a processing procedure in the method for controlling the ophthalmologic apparatus according to the embodiment of the present invention.

When the subject H places his / her chin on the chin rest 112 (S101), the examiner operates the joystick 101 so that the subject's eye E is reflected on the observation screen of the LCD monitor 116.

Then, when the examiner confirms the observation screen of the LCD monitor 116 and presses the measurement start switch 404, the system control unit 401 detects this and performs a process of starting measurement.

Subsequently, in step S103, the system control unit 401 determines whether the eye E is not an IOL insertion eye.

If it is determined in step S103 that the eye E is not an IOL insertion eye (a healthy eye) (S103 / YES), the process proceeds to step S104.

In step S104, the system control unit 401 performs alignment using the alignment bright spot image. Specifically, in step S104, the system control unit 401 determines that the three alignment bright spot images are vertically aligned as described above with reference to FIG. 6 and the predetermined position at the center of the image sensor 220 is appropriate. Judged as a position. In step S104, when the alignment bright spot image is not at an appropriate position, the system control unit 401 calculates the amount of positional deviation, and for example, sets the measurement section 110 so that the alignment bright spot image is at an appropriate position. Positioning is performed by controlling driving in the XYZ directions.

When the alignment bright spot image is at an appropriate position, subsequently, in step S107, the system control unit 401 performs kerato measurement.

Subsequently, in step S108, the system control unit 401 performs reflex measurement.

Then, when the process of step S108 is completed, the process of the flowchart shown in FIG.

If the result of determination in step S103 is that the eye E is an IOL insertion eye (S103 / NO), the process proceeds to step S105.

In step S105, the system control unit 401 performs processing for detecting the pupil Ep of the eye E to be examined.

FIG. 13 is a diagram for explaining the pupil detection processing in step S105 shown in FIG. In step S105, the anterior segment image as shown in FIG. 13A is binarized with a predetermined value (predetermined level). Then, as shown in FIG. 13B, the edge portion of the pupil Ep becomes clear by using the contrast difference, and the pupil Ep can be detected.

Subsequently, in step S106, the system control unit 401 performs positioning by driving the measurement unit 110 in the XY directions, for example, so that the center position of the pupil Ep detected in step S105 is an appropriate position.

Thus, when alignment is performed at the center position of the pupil Ep, the measurement light of the eye E is not kicked by the iris, and there is an effect of reducing measurement errors.

When the process of step S106 is completed, the process proceeds to step S107, and the system control unit 401 drives the corneal curvature

radius light sources

224a and 224b and performs kerato measurement (measurement of corneal curvature radius).

Subsequently, in step S108, the system control unit 401 drives the measurement light source (eye refractive power measurement light source) 201 and performs reflex measurement (eye refractive power measurement).
Then, when the process of step S108 ends, the process of the flowchart shown in FIG. 12 ends.

Next, a detailed processing procedure of the IOL insertion eye determination process in step S103 of FIG. 12 will be described.

FIG. 14 is a flowchart illustrating an example of a detailed processing procedure in the IOL insertion eye determination process in step S103 illustrated in FIG.

First, in step S201, the system control unit 401 turns on the anterior eye

illumination light sources

221a and 221b and turns off the measurement light source 201 that is an alignment light source, and displays an image of the eye E on the image sensor 220. Let's take an image. Next, the system control unit 401 extracts a cornea reflection image reflected by the cornea Ec of the eye E from the image captured by the image sensor 220. That is, since the image captured by the image sensor 220 is an image based on the luminous flux of only the anterior

illumination light sources

221a and 221b, the extracted cornea reflection image is also based on the luminous flux of only the anterior

illumination light sources

221a and 221b. It becomes.

FIG. 15 is a diagram for explaining the cornea reflection image extraction processing in step S201 shown in FIG.

FIG. 15A is an example of an image captured by the image sensor 220. FIGS. 15B and 15C are examples of images obtained by binarizing the image shown in FIG. 15A with a predetermined value (predetermined level). In FIG. 15B and FIG. 15C, bright spots that are equal to or higher than a predetermined value (a predetermined level or higher) are shown. By detecting this bright spot, a cornea reflection image can be extracted.

Subsequently, in step S202, the system control unit 401 determines whether the number n of bright spots of the cornea reflection image extracted in step S201 is n = 2.

If the number n of bright spots in the cornea reflection image extracted in step S201 is n = 2 as a result of the determination in step S202 (S202 / YES), the process proceeds to step S203.

In step S203, the system control unit 401 calculates the amount of deviation from the appropriate position of the images by the anterior ocular

illumination light sources

221a and 221b based on the cornea reflection image extracted in step S201. Then, the system control unit 401 performs positioning by driving and controlling the measurement unit 110 in the XYZ directions, for example, according to the calculated deviation amount.

The subsequent step S204 is a step for performing further detailed alignment.

In step S204, the system control unit 401 turns off the anterior

illumination light sources

221a and 221b and turns on the measurement light source 201, which is an alignment light source, and displays the image of the eye E on the image sensor 220. Let's take an image. Next, the system control unit 401 extracts a cornea reflection image reflected by the cornea Ec of the eye E from the image captured by the image sensor 220. That is, since the image captured by the image sensor 220 is an image based on the light flux of only the measurement light source 201 as the alignment light source, the extracted corneal reflection image is also based on the alignment bright spot image.

FIG. 16 is a diagram for explaining the cornea reflection image extraction processing in step S204 shown in FIG.

FIG. 16A is an example of an image captured by the image sensor 220. FIGS. 16B and 16C are examples of images obtained by binarizing the image shown in FIG. 16A with a predetermined value (predetermined level). In FIG. 16B and FIG. 16C, bright spots that are equal to or higher than a predetermined value (a predetermined level or higher) are shown. By detecting this bright spot, a cornea reflection image can be extracted.

Subsequent step S205 is a step of determining whether the eye E is an IOL insertion eye from the alignment bright spot image.

In step S205, the system control unit 401 determines whether the number n of bright spots in the cornea reflection image (alignment bright spot image) extracted in step S204 is n = 3.

If the number n of bright spots in the cornea reflection image (alignment bright spot image) extracted in step S204 is n = 3 as a result of the determination in step S205 (S205 / YES), the process proceeds to step S104 in FIG. . That is, as shown in FIG. 16C, when the number n of bright spots is n = 3, the process proceeds to step S104 in FIG. 12 to perform alignment using the alignment bright spot image.

On the other hand, if the number n of bright spots in the cornea reflection image (alignment bright spot image) extracted in step S204 is not n = 3 as a result of the determination in step S205 (S205 / NO), the process proceeds to step S105 in FIG. To do. That is, as shown in FIG. 16C, when the number n of bright spots is n ≠ 3, the process proceeds to step S105 in FIG. 12, pupil detection is performed, and then in step S106, the pupil center is appropriate. Alignment is performed in the XY direction so as to obtain a correct position.

If the number n of bright spots in the cornea reflection image extracted in step S201 is not n = 2 as a result of the determination in step S202 (S202 / NO), the process proceeds to step S206.

In step S206, the system control unit 401 drives the measurement unit 110 by a predetermined amount in the X direction, for example. Here, the driving direction may be moved to the ear side of the eye E (right side with respect to the eye E) in the case of FIG. 15B from the generation mechanism of the reflected ghost image by the IOL. In the case of FIG. 15B, since the measurement unit 110 is displaced to the nasal side (left side) with respect to the eye E, a reflected ghost image (P4 ') due to the IOL is generated.

After driving in the X direction in step S206, subsequently, in step S207, the system control unit 401, like step S201, an anterior ocular illumination image (corneal reflection image) based on the luminous fluxes of only the anterior ocular

illumination light sources

221a and 221b. ).

Subsequently, in step S208, the system control unit 401 determines whether or not the number n of bright spots in the anterior ocular illumination image (corneal reflection image) extracted in step S207 is n = 2.

If the number n of bright spots in the anterior ocular illumination image (corneal reflection image) extracted in step S207 is not n = 2 as a result of the determination in step S208 (S208 / NO), the process returns to step S206, and again in step S206. Perform the following processing.

On the other hand, if the number n of bright spots of the anterior ocular illumination image (corneal reflection image) extracted in step S207 is n = 2 (S208 / YES), the process proceeds to step S209. For example, as shown in FIG. 15C, if the number n of bright spots in the anterior ocular illumination image (corneal reflection image) is n = 2, the process proceeds to step S209.

In step S209, the system control unit 401 calculates the distance between two anterior eye illumination images (corneal reflection images) and performs measurement. At this time, since the interval between the two anterior eye illumination images changes depending on the working distance between the eye E and the measuring unit 110, it can be confirmed if the working distance is determined in advance.

Subsequently, in step S210, the system control unit 401 calculates a deviation amount between the distance between the two anterior ocular illumination images (corneal reflection images) measured in step S209 and the appropriate working distance. Then, the system control unit 401 performs alignment by driving and controlling the measurement unit 110 in the Z direction, for example, according to the calculated deviation amount.

When the processing in step S210 is completed, the process proceeds to step S105 in FIG. 12, pupil detection is performed, and then in step S106, alignment is performed in the XY directions so that the pupil center is in an appropriate position.

In the description of the flowchart of FIG. 12 described above, when the eye E is an IOL insertion eye (S103 / NO), pupil detection is performed in step S105, and then alignment in the XY directions, kerato measurement, and reflex measurement (S106). To S108).

In rare cases, when a portion of the iris of the eye E is cut off and the pupil Ep is distorted, it is possible to align with a ring image of kerato measurement.

FIG. 17 is a flowchart illustrating an example of a processing procedure according to the modification example after it is determined that the eye E to be examined is an IOL insertion eye in Step S103 illustrated in FIG. 12 (S103 / NO).

In this modification, when it is determined in step S103 in FIG. 12 that the eye E is an IOL insertion eye (S103 / NO), the process proceeds to step S301 in FIG.

In step S301, the system control unit 401 performs processing for detecting a corneal ring image. At this time, the corneal ring image is a ring image based on the luminous flux from the ring light sources including the corneal curvature

radius light sources

224a and 224b. In step S301, the corneal ring image has a predetermined value higher than the light amount at the time of kerato measurement in step S107 in FIG. It is obtained by turning on the corneal curvature radius light source with the amount of light.

FIG. 18 is a diagram for explaining the corneal ring image detection process in step S301 shown in FIG.

FIG. 18A is an example of an image captured by the image sensor 220 by turning on the corneal

curvature light sources

224a and 224b under the above-described conditions. In FIG. 18A, a corneal ring image Q1 is shown.

In the process of step S301, only the corneal ring image Q1 ′ shown in FIG. 18B is obtained by binarizing the image shown in FIG. 18A with a predetermined value (predetermined level) and using the contrast difference. Can be detected.

Subsequently, in step S302, the system control unit 401 obtains the ring center position of the corneal ring image detected in step S301, and calculates the amount of deviation from the appropriate position in the XY direction. Then, the system control unit 401 performs drive control of the measurement unit 110 in the XY directions, for example, according to the calculated deviation amount, and performs alignment at an appropriate position.

When the processing in step S302 is completed, the process proceeds to step S107 in FIG.

In the ophthalmologic apparatus according to the present embodiment described above, the eye E illuminated by the measurement light source 201, which is one of the illumination means, is imaged, and the cornea Ec of the eye E is obtained from the image obtained by the imaging. The reflected cornea reflection image is extracted (S204 in FIG. 14). In the ophthalmologic apparatus according to the present embodiment, it is determined whether an IOL (intraocular lens) is inserted in the eye E based on the cornea reflection image (S205 in FIG. 14, S103 in FIG. 12), The relative positioning method between the eye E and the ophthalmologic apparatus is changed according to the result of the determination (S104 in FIG. 12 and S105 and S106 in FIG. 12, or S104 in FIG. 12). S301 and S302 in FIG.

According to such a configuration, even when the IOL is inserted into the eye E, it is possible to perform relative alignment between the eye to be examined and the ophthalmologic apparatus after removing the reflected ghost image by the IOL. Accordingly, it is possible to suppress erroneous detection of the alignment index, and thus it is possible to perform relative alignment between the eye to be examined and the ophthalmologic apparatus with high accuracy.

(Other embodiments)
The present invention can also be realized by executing the following processing.

That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, etc.) of the system or apparatus reads the program. It is a process to be executed.

This program and a computer-readable recording medium storing the program are included in the present invention.

Note that the above-described embodiments of the present invention are merely examples of implementation in practicing the present invention, and the technical scope of the present invention should not be construed as being limited thereto. It is. That is, the present invention can be implemented in various forms without departing from the technical idea or the main features thereof.

This application claims priority on the basis of Japanese Patent Application No. 2013-236136 filed on November 14, 2013, the entire contents of which are incorporated herein by reference.

DESCRIPTION OF SYMBOLS 100 Base part 101 Joystick 102 Frame 103 X-axis motor 104 Y-axis motor 105 Feed screw 106 Frame 107 Frame 108 Z-axis motor 109 Feed screw 110 Measuring part 111 Light source unit 112 Jaw holder 113 Jaw holder motor 114 Nut 115 Nut 116 LCD monitor 120 Drive unit 130 Operation unit H Subject E Subject eye

Claims

An ophthalmic apparatus for measuring an eye to be examined,
Illuminating means for illuminating the eye to be examined;
Imaging means for imaging the eye to be examined illuminated by the illumination means;
Extraction means for extracting a cornea reflection image reflected by the cornea of the eye to be examined from an image obtained by imaging by the imaging means;
Determination means for determining whether an intraocular lens is inserted in the eye to be examined based on the cornea reflection image;
An ophthalmic apparatus comprising: an alignment unit that changes a relative alignment method between the eye to be examined and the ophthalmic apparatus according to a result of the determination unit.
The illumination means includes an anterior eye illumination light source that illuminates the anterior eye portion of the eye to be examined,
When the determination unit determines that an intraocular lens is inserted in the eye to be examined, the imaging unit is configured to illuminate an anterior segment of the eye with the anterior illumination light source. Detecting the pupil of the eye to be inspected from the anterior eye image obtained by imaging, and performing a relative alignment between the eye to be examined and the ophthalmologic apparatus based on the position of the detected pupil The ophthalmic apparatus according to claim 1.
3. The ophthalmologic apparatus according to claim 2, wherein the alignment unit binarizes the anterior eye image with a predetermined value and detects a pupil of the eye to be examined using a contrast difference.
The illumination means includes a ring light source that illuminates the cornea of the eye to be examined in a ring shape,
The positioning means is obtained by imaging by the imaging means in a state where the cornea of the eye to be examined is illuminated by the ring light source when the judging means judges that an intraocular lens is inserted in the eye to be examined. The ophthalmic apparatus according to claim 1, wherein a ring image is detected from the obtained image, and relative alignment between the eye to be examined and the ophthalmic apparatus is performed based on a center position of the detected ring image. .
The positioning means binarizes an image obtained by imaging by the imaging means in a state where the cornea of the eye to be examined is illuminated by the ring light source, and uses the contrast difference to binarize the ring. The ophthalmologic apparatus according to claim 4, wherein an image is detected.
A diaphragm further between the eye to be examined and the imaging means;
When the determining unit determines that an intraocular lens is not inserted into the eye to be examined, the alignment unit determines a bright spot based on the aperture from an image obtained by imaging by the imaging unit via the aperture The ophthalmologic apparatus according to claim 1, wherein an image is detected and relative alignment between the eye to be examined and the ophthalmologic apparatus is performed based on a position of the bright spot image. .
The ophthalmic apparatus according to any one of claims 1 to 6, wherein the alignment unit performs the alignment by driving the ophthalmologic apparatus in an X direction related to a left-right direction.
A method for controlling an ophthalmologic apparatus for measuring an eye to be examined,
An imaging step of imaging the eye to be examined illuminated by the illumination means;
An extraction step of extracting a cornea reflection image reflected by the cornea of the eye to be examined from an image obtained by imaging in the imaging step;
A determination step of determining whether an intraocular lens is inserted into the eye to be examined based on the cornea reflection image;
An ophthalmologic apparatus control method comprising: an alignment step of changing a relative alignment technique between the eye to be examined and the ophthalmologic apparatus according to a result of the determination step.