JP2023024761A - Ophthalmologic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ophthalmologic apparatus capable of performing an examination on strabismus and heterophoria of an eye to be examined quickly and easily.

SOLUTION: An ophthalmologic apparatus 10 includes: a measurement optical system 21; an image pickup device 31g as an image acquisition unit; a target projection system 32; a rotational drive unit 24, 25; a pupil center detection unit 26c for detecting a pupil center of an eye to be examined from an image of the anterior eye part of the eye to be examined acquired by the image pickup device 31g in a state that a fixation target is presented; and a corneal reflex position detection unit 26d for detecting a position of the corneal reflex of the eye to be examined on the basis of a point image obtained when a light parallel to an optical axis incident onto the eye to be examined from the measurement optical system 21 is imaged in the eye to be examined. The rotational drive unit 24, 25 rotates the measurement optical system 21 with an eyeball rotation axis of the eye to be examined as a central axis so that the pupil center coincides with the position of the corneal reflex.

SELECTED DRAWING: Figure 5

COPYRIGHT: (C)2023,JPO&INPIT

Description

The present invention relates to an ophthalmic device.

When an optotype is presented to the eye to be inspected to acquire eye characteristics, the eye to be inspected rotates around the axis of rotation of the eyeball according to the distance between the optotype and the eye to be inspected. That is, by dilating or converging the subject's eye, it is possible to perform a distance examination or a near examination. An ophthalmic apparatus capable of rotating a measurement optical system about an eyeball rotation axis corresponding to such rotation of an eye to be examined has been disclosed (see, for example, Patent Document 1).

By the way, if the subject's eye has squint or oblique position, it may not be possible to fixate the visual target, and the eye characteristics may not be obtained accurately. Therefore, it is necessary to acquire eye characteristics after correcting strabismus and oblique posture.

Such squint and oblique correction is performed by spectacles (prism spectacles). This squint and squint inspection for correction is performed manually by ophthalmologists, orthoptists, and optician shop clerks through manual inspections that require skill and experience. , there is a problem that the subject also feels tired.

Japanese Patent No. 5635976

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ophthalmologic apparatus capable of quickly and easily examining strabismus and squint of an eye to be examined.

In order to achieve the above object, an ophthalmologic apparatus of the present invention includes a measuring optical system for acquiring information on an eye to be examined of a subject; and an eye target projection system that presents a fixation target to the eye on the optical axis of the measurement optical system for causing fixation of the line of sight of the eye to be inspected. a rotation driving unit that rotates the measurement optical system around an eyeball rotation axis of the eye to be inspected; a pupil center detection unit for detecting the center of the pupil of the eye to be examined; a corneal reflection position detection unit for detecting the position of the corneal reflection of the eye to be inspected based on the measurement optical system; is rotated around the eyeball rotation axis of the eye to be examined.

In the ophthalmologic apparatus configured as described above, the measurement optical system is rotated by the rotation driving section so that the center of the pupil and the corneal reflection based on the point image are aligned. As a result, even when the subject's eye has squint or oblique position, the visual axis can be aligned with the optical axis of the measurement optical system. Therefore, according to the ophthalmologic apparatus of the present invention, it is possible to quickly and easily examine strabismus and squint of the subject's eye.

1 is a perspective view showing the overall configuration of an ophthalmologic apparatus according to an embodiment; FIG. FIG. 3 is a diagram showing the detailed configuration of the right-eye measurement optical system of the ophthalmologic apparatus according to the present embodiment; 1 is a perspective view showing an example of a rotary prism used in an ophthalmologic apparatus according to this embodiment; FIG. 1 is a block diagram showing the overall configuration of an ophthalmologic apparatus according to an embodiment; FIG. 2 is a block diagram showing the configuration of the control system of the ophthalmologic apparatus according to this embodiment; FIG. FIG. 2 is a schematic diagram showing the relationship between the visual axis and pupillary axis of an eye to be examined; FIG. 3 is a diagram showing a point image formed inside an eye to be inspected by a point light source; FIG. 3 is a diagram showing a type of perspective; FIG. 4 is a diagram showing the positions of the pupil center and the corneal reflection in the anterior segment image acquired by the ophthalmologic apparatus according to the present embodiment; FIG. 4 is an explanatory diagram for explaining the relationship between various images displayed on the display unit; FIG. 10 is a diagram showing the displacement of the position of the corneal reflex with respect to the position of the pupil center; FIG. 4 is a diagram for explaining an angle formed between a pupil axis and an optical axis of a measurement optical system; FIG. 10 is a diagram for explaining a rotating state of the measuring head by the measuring head control section; 4 is a flow chart for explaining the operation of the ophthalmologic apparatus according to the embodiment; FIG. 4 is a diagram showing an example of a screen displayed on the display unit of the ophthalmologic apparatus according to the present embodiment;

An ophthalmologic apparatus according to this embodiment will be described below. First, the overall configuration of an ophthalmologic apparatus 10 according to the present embodiment will be described with reference to FIGS. 1 to 5. FIG. The ophthalmologic apparatus 10 of the present embodiment is a binocular open type ophthalmologic apparatus capable of simultaneously measuring characteristics of the subject's eye with both the left and right eyes of the subject open. It should be noted that the ophthalmologic apparatus of the present embodiment can also inspect one eye at a time by shielding one eye or turning off the fixation target. Further, the ophthalmic apparatus is not limited to the binocular open type, and the present invention can also be applied to an ophthalmic apparatus that measures characteristics for each eye.

The ophthalmologic apparatus 10 of the present embodiment performs at least one of arbitrary subjective examinations and arbitrary objective examinations. In the subjective test, a target is presented to the subject, and the test result is obtained based on the subject's response to the target. The subjective examination includes subjective refraction measurement such as distance examination, near examination, contrast examination, glare examination, visual field examination, and the like. In the objective test, the eye to be inspected is irradiated with light, and information (characteristics) about the eye to be inspected is measured based on the detection result of the returned light. This objective examination includes measurement for acquiring characteristics of the eye to be inspected and photographing for acquiring an image of the eye to be inspected. Furthermore, objective refraction measurement (reflection measurement), corneal shape measurement (keratometric measurement), intraocular pressure measurement, fundus photography, and optical coherence tomography (hereinafter referred to as "OCT") are used for the objective examination. There are tomographic imaging (OCT imaging), measurement using OCT, and the like.

[Overall Configuration of Ophthalmic Device]
The ophthalmologic apparatus 10 of the present embodiment includes a base 11, an optometry table 12, a post 13, an arm 14, a driving mechanism (driving section) 15, and a pair of measuring heads 16, as shown in FIG. In the ophthalmologic apparatus 10 , the subject facing the eye examination table 12 holds the forehead support 17 provided between the two measurement heads 16 , and obtains information on the eye to be examined of the subject. In addition, as shown in FIG. 1 throughout this specification, the X axis, Y axis, and Z axis are taken, and when viewed from the subject, the horizontal direction is the X direction, the vertical direction (vertical direction) is the Y direction, and the X direction is And the direction perpendicular to the Y direction (depth direction of the measuring head 16) is defined as the Z direction.

The eye examination table 12 is a desk on which a display section/examiner controller (hereinafter simply referred to as an "examiner controller") 27 and a subject controller 28, which will be described later, are placed, and other items used for eye examination are placed. It is supported by the base 11 . The optometric table 12 may be supported by the base 11 so that its position in the Y direction (height position) can be adjusted.

The post 13 is supported by the base 11 so as to extend in the Y direction at the rear end of the optometry table 12, and has an arm 14 at its tip. The arm 14 suspends both measuring heads 16 on the optometry table 12 via the drive mechanism 15, and extends from the support 13 toward the front side in the Z direction. The arm 14 is movable in the Y direction with respect to the column 13 . In addition, the arm 14 may be movable in the X direction and the Z direction with respect to the column 13 . A pair of measuring heads 16 are suspended from the tip of the arm 14 by a drive mechanism 15 and supported.

The measuring heads 16 are provided in pairs so as to individually correspond to the left and right eyes of the subject, and hereinafter, the left eye measuring head 16L and the right eye measuring head 16R will be referred to individually. . The left eye measurement head 16L acquires information on the left eye of the subject, and the right eye measurement head 16R acquires information on the right eye of the subject. The left-eye measurement head 16L and the right-eye measurement head 16R are configured to be symmetrical with respect to a vertical plane positioned between them in the X direction.

Each measuring head 16 is provided with a mirror 18 as a deflecting member, and through the mirror 18, a measuring optical system 21, which will be described later, acquires information on the corresponding subject's eye.

Each measurement head 16 is provided with a measurement optical system 21 (to be referred to as a right eye measurement optical system 21R and a left eye measurement optical system 21L when individually described) that acquires eye information of an eye to be examined. A detailed configuration of the measurement optical system 21 will be described later.

Both measuring heads 16 are movably suspended by a drive mechanism 15 provided on a base portion 19 suspended from the tip of the arm 14 . In this embodiment, as shown in FIG. 4, the drive mechanism 15 includes a left eye drive mechanism 15L corresponding to the left eye measurement head 16L and a right eye drive mechanism 15R corresponding to the right eye measurement head 16R. and have The left eye drive mechanism 15L includes a left eye vertical drive section 22L, a left eye horizontal drive section 23L, a left eye X direction rotation drive section (left eye horizontal direction rotation drive section) 24L, and a left eye Y direction rotation drive section. It has a drive section (vertical rotation drive section for left eye) 25L. The right-eye drive mechanism 15R includes a right-eye vertical drive section 22R, a right-eye horizontal drive section 23R, a right-eye X-direction rotation drive section (right-eye horizontal rotation drive section) 24R, and a right-eye Y-direction rotation drive section. It has a drive section (vertical rotation drive section for right eye) 25R.

The configuration of each drive unit corresponding to the left-eye measurement head 16L and the configuration of each drive unit corresponding to the right-eye measurement head 16R are symmetrical with respect to a vertical plane positioned between them in the X direction. It is Hereinafter, the vertical drive section 22, the horizontal drive section 23, the X-direction rotation drive section 24, and the Y-direction rotation drive section 25 may be simply referred to, unless otherwise specified. The same applies to other components that are provided symmetrically to the left and right.

In the drive mechanism 15, as shown in FIG. 4, a vertical drive section 22, a horizontal drive section 23, an X-direction rotation drive section 24, and a Y-direction rotation drive section 25 are arranged in this order from above.

The vertical drive section 22 is fixed to the base section 19 at the tip of the arm 14, and moves the horizontal drive section 23, the X-direction rotation drive section 24, and the Y-direction rotation drive section 25 with respect to the arm 14 in the Y direction (vertical direction). Let The horizontal drive section 23 is fixed to the vertical drive section 22 and moves the X-direction rotation drive section 24 and the Y-direction rotation drive section 25 with respect to the vertical drive section 22 in the X direction and the Z direction (horizontal direction).

The vertical driving section 22 and the horizontal driving section 23 are provided with an actuator such as a pulse motor for generating driving force, and a transmission mechanism such as a combination of gears or a rack and pinion for transmitting the driving force. consists of The horizontal driving unit 23 can be easily configured and can easily control horizontal movement by providing a combination of actuators and transmission mechanisms separately for the X direction and the Z direction, for example.

The X-direction rotation driving section 24 is connected to the horizontal driving section 23 . The X-direction rotation drive unit 24 moves the corresponding measurement head 16 and the Y-direction rotation drive unit 25 to the horizontal drive unit 23 at the corresponding eyeball rotation points O (the left eyeball rotation points OL and OL shown in FIG. 4). With the eyeball rotation axis v (vL and vR indicated by dashed lines in the left eye EL and right eye ER in FIG. 4) extending in the vertical direction (Y direction) passing through the right eyeball rotation point OR) as the center (rotation axis), Rotate in the X direction (horizontal direction).

The Y-direction rotation driving section 25 is connected to the X-direction rotation driving section 24 . A measurement head 16 is suspended from the Y-direction rotation drive unit 25 . The Y-direction rotation drive unit 25 moves the corresponding measurement head 16 to the X-direction rotation drive unit 24 at the eyeball rotation point O (the left eyeball rotation point OL and the right eyeball rotation point OR, see FIG. 4) of the corresponding eye E to be examined. ) extending in the horizontal direction (X direction) (hL and hR indicated by two-dot chain lines in the left eye EL and right eye ER in FIG. 4) as the center (rotation axis), and the Y direction (vertical up and down direction).

The X-direction rotation driving section 24 and the Y-direction rotation driving section 25 can be configured such that, for example, a transmission mechanism that receives driving force from an actuator moves along an arcuate guide groove. By aligning the center positions of the guide grooves with the eyeball rotation axes h (hL, hV) and v (vL, vR), the X-direction rotation drive unit 24 and the Y-direction rotation drive unit 25 rotate the eyeball E to be examined. The measuring head 16 can be pivoted about the axes v(vL, vR), h(hL, hV).

The X-direction rotation driving section 24 supports the Y-direction rotation driving section 25 and the measuring head 16 so as to be rotatable about its own rotation axis, and also supports the measuring head 16 in cooperation with the horizontal driving section 23 . It is good also as a structure made to rotate, changing the position to which it carries out. The Y-direction rotation drive unit 25 supports the measurement head 16 so as to be rotatable about its own rotation axis, and cooperates with the vertical drive unit 22 to rotate while changing the position at which the measurement head 16 is supported. It may be configured to allow

With the above configuration, the driving mechanism 15 can move the measuring heads 16 individually or in conjunction with each other in the X, Y and Z directions, and can move the measuring heads 16 around the eyeball rotation axes v and h of the subject's eye. It can be rotated in the X and Y directions. Note that the ophthalmologic apparatus 10 of the present embodiment receives a control signal from the control unit 26 to drive the drive units 22 to 25 of the drive mechanism 15 to move and rotate the measurement heads 16 . Further, it is also possible to manually drive each drive unit 22 to 25 in response to a manual operation by an examiner or the like to move and rotate each measurement head 16 .

Further, by rotating the left-eye measurement head 16L and the right-eye measurement head 16R in the X direction (horizontal direction) by the left-eye X-direction rotation drive unit 24L and the right-eye X-direction rotation drive unit 24R, The subject's eye E can be diverged (divergence movement) or converged (convergence movement). Further, by rotating the left-eye measurement head 16L and the right-eye measurement head 16R in the Y direction (vertical direction) by the left-eye Y-direction rotation drive unit 25L and the right-eye Y-direction rotation drive unit 25R, The line of sight of the subject's eye E can be directed downward or returned to its original position. As a result, the ophthalmologic apparatus 10 can perform divergence motion and convergence motion tests, and perform distance and near vision tests in the state of binocular vision to measure various characteristics of both eyes to be examined.

As shown in FIG. 1 or FIG. 5, the base 11 is provided with a control section 26 that controls each section of the ophthalmologic apparatus 10 in an integrated manner. The ophthalmologic apparatus 10 also includes an examiner controller 27 that is used by the examiner to operate the ophthalmologic apparatus 10, and a controller 27 that is used by the examinee to respond when acquiring various types of eye information of the eye to be examined. and a subject controller 28 configured to be a subject.

The examiner controller 27 is an information processing device capable of short-distance communication with the control unit 26, such as a tablet terminal or a smartphone. Note that the examiner controller 27 is not limited to a tablet terminal or the like, and may be a notebook personal computer, a desktop personal computer, or the like. Alternatively, a controller dedicated to the ophthalmologic apparatus 10 may be used.

In the ophthalmologic apparatus 10 of the present embodiment, the examiner controller 27 is configured to be portable, and may be operated while placed on the optometric table 12, or may be held by the examiner's hand. may be manipulated.

The subject controller 28 includes input devices such as a keyboard, mouse, and joystick. The subject controller 28 is connected to the controller 26 via a wired or wireless communication path.

[Measuring optical system]
The left-eye measurement optical system 21L and the right-eye measurement optical system 21R are a visual acuity test apparatus that performs a visual acuity test while switching the visual target to be presented, and an appropriate corrective refractive power of the eye to be inspected while switching and arranging corrective lenses. Acquisition phoropter, refractometer and wavefront sensor for measuring refractive power, fundus camera for taking images of the fundus, tomography device for taking tomographic images of the retina, specular microscope for taking images of the corneal endothelium, corneal shape measurement A keratometer for measuring intraocular pressure, a tonometer for measuring intraocular pressure, and the like are configured singly or in combination.

FIG. 2 is a diagram showing the detailed configuration of the right-eye measuring optical system 21R in the ophthalmologic apparatus according to the present embodiment. The mirror 18R is omitted in FIG. Since the configuration of the left-eye measurement optical system 21L is the same as that of the right-eye measurement optical system 21R, the description thereof will be omitted, and only the right-eye measurement optical system 21R will be described below.

The right eye measurement optical system 21R has an observation system 31, a target projection system 32, an eye refractive power measurement system 33, an alignment system 35, an alignment system 36, and a keratometric system 37, as shown in FIG.

An observation system 31 observes the anterior segment of the eye to be examined E, a target projection system 32 presents a target to the eye E to be examined, and an eye refractive power measurement system 33 measures eye refractive power. In this embodiment, the eye refractive power measurement system 33 has a function of projecting a predetermined measurement pattern onto the fundus Ef of the eye to be examined E and a function of detecting an image of the measurement pattern projected onto the fundus Ef.

The alignment system 35 and the alignment system 36 align the optical system with the eye E to be examined. Alignment system 35 performs alignment in directions along the optical axis of observation system 31 (forward and backward direction, Z direction), and alignment system 36 performs alignment in directions perpendicular to the optical axis (vertical direction and lateral direction; Y direction and X direction). Align each.

The observation system 31 has an objective lens 31a, a dichroic filter 31b, a half mirror 31c, a relay lens 31d, a dichroic filter 31e, an imaging lens 31f, and an imaging device (CCD) 31g as an image acquisition section.

In the observation system 31, the luminous flux reflected by the subject's eye E (anterior segment) passes through the objective lens 31a and forms an image on the imaging element 31g by the imaging lens 31f. As a result, an anterior ocular segment image E′ is formed on the imaging element 31g by projecting (projecting) a keratling light flux, a light flux from the alignment light source 35a, and a light flux (bright spot image Br) from the alignment light source 36a, which will be described later. be. The imaging device 31g of the observation system 31 captures this anterior segment image E'. The control unit 26 causes the display surface 30a of the display unit 30 of the examiner's controller 27 to display an anterior segment image E' and the like based on the image signal output from the imaging device 31g.

A kerat system 37 is provided in front of the objective lens 31a. Kerato system 37 comprises a kerato plate 37a and a kerato ring light source 37b. The keratoplate 37a has a plate shape provided with a slit concentric with respect to the optical axis of the observation system 31, and is provided near the objective lens 31a. The keratizing light source 37b is provided in alignment with the slit of the keratoplate 37a.

In the kerato system 37, a light flux from a lighted keratizing light source 37b passes through the slit of the kerato plate 37a, so that a keratling light flux (corneal curvature measuring ring shape) for measuring the shape of the cornea is directed to the subject's eye E (cornea Ec). Target) is projected (projected). The keratling luminous flux is reflected by the cornea Ec of the eye E to be examined, and is imaged on the imaging device 31g by the observation system 31 . As a result, the imaging device 31g detects (receives) an image (image) of the ring-shaped keratling light flux, and the control unit 26 causes the display surface 30a of the display unit 30 to display the image of the measurement pattern, and the image The corneal shape (curvature radius) is measured by a well-known technique based on the image signal from the (imaging device 31g).

In this embodiment, an example (kerat system 37) using a keratoplate 37a for measuring the curvature near the center of the cornea with one to three ring slits is shown as the corneal topography measurement system. As long as the corneal shape is measured, a placide plate having multiple rings and capable of measuring the shape of the entire cornea may be used, or other configurations may be used, and the configuration is not limited to the configuration of this embodiment.

An alignment system 35 is provided behind the kerat system 37 (kerat plate 37a). The alignment system 35 has a pair of an alignment light source 35a and a projection lens 35b. A light beam from each alignment light source 35a is made into a parallel light beam by each projection lens 35b, and the cornea of the eye E to be examined passes through an alignment hole provided in a kerato plate 37a. The parallel luminous flux is projected (projected) onto Ec.

The control unit 26 or the examiner moves the measuring head 16 in the front-rear direction based on the bright spots (bright spot images) projected (projected) on the cornea Ec, thereby moving the measuring head 16 in the direction along the optical axis of the observation system 31 ( fore-and-aft direction) alignment. This alignment in the longitudinal direction is performed by adjusting the position of the measuring head 16 so that the ratio of the distance between the two point images by the alignment light source 35a on the imaging device 31g and the diameter of the keratling image is within a predetermined range.

In this embodiment, the optical axis of the measurement optical system 21 is bent by the mirror 18, and the optical axis of the measurement optical system 21 substantially coincides with the Z-axis at the position of the mirror image of the measurement optical system 21 with respect to the mirror 18. is configured to Therefore, alignment in the optical axis direction of the measurement optical system 21 corresponds to alignment in the Z direction.

Here, the control unit 26 may obtain the amount of misalignment from the ratio and display the amount of misalignment on the display surface 30a. Note that the alignment in the front-rear direction may be performed by adjusting the position of the measuring head 16R so that the bright spot image Br is focused by the alignment light source 36a, which will be described later.

Further, the observation system 31 is provided with an alignment system (parallel optical system) 36 . The alignment system 36 has an alignment light source 36a and a projection lens 36b, and shares a half mirror 31c, a dichroic filter 31b and an objective lens 31a with the observation system 31.

The alignment system 36 emits (projects) a light flux from an alignment light source (point light source) 36a onto the cornea Ec of the subject's eye E as a parallel light flux through the objective lens 31a. A parallel light beam projected from the alignment system 36 onto the cornea Ec of the eye to be examined E forms a bright spot Q of the alignment light at a substantially intermediate position between the corneal apex Ept and the center of curvature _R0 of the cornea (see FIG. 7). The control unit 26 or the examiner moves the measurement head 16 in the front-rear direction based on the image (bright point image) Br of the bright point Q projected onto the cornea Ec, thereby adjusting the optical axis of the observation system 31. Alignment is performed in the direction (vertical direction, horizontal direction) perpendicular to the

At this time, the control unit 26 causes the display surface 30a to display an alignment mark AL serving as a reference for the alignment mark in addition to the anterior segment image E' formed with the bright spot image Br. The control unit 26 may be configured to perform control so as to start measurement when alignment is completed.

The alignment light source 36a is a light-emitting diode that emits infrared light (for example, 940 nm) in order to prevent the subject from viewing the alignment light source 36a while the alignment system 36 is performing alignment operations.

The visual target projection system 32 is an optical system that projects a visual target in order to fixate and cloud the eye E to be examined, and presents it on the fundus oculi Ef. The visual target projection system 32 has a display 32a, rotary prisms 32A and 32B, an imaging lens 32b, a moving lens 32c, a relay lens 32d, a field lens 32f, a mirror 32h and a dichroic filter 32i. is shared with the observation system 31.

The display 32a displays a landscape chart for visual fixation and cloudiness, Landolt's ring, an E-character optotype, and an optometry optotype, etc., when performing an objective test and a subjective test.

An electronic display device such as EL (electroluminescence) or liquid crystal display (LCD) can be used as the display 32a, and an arbitrary image is displayed under the control of the control section 26. FIG. The display 32a is movably provided along the optical axis at a position conjugate with the fundus Ef of the subject's eye E on the optical path of the target projection system 32 .

The rotary prisms 32A, 32B are used to adjust the prism power and prism base direction in the oblique examination. The rotary prisms 32A and 32B are independently rotated by driving a pulse motor or the like. As shown in FIG. 3, when the rotary prisms 32A and 32B are rotated in opposite directions, the prism power is continuously changed, and when they are rotated together in the same direction, the prism base direction is continuously changed. be.

The moving lens 32c is driven forward and backward along the optical axis by a drive motor. By moving the moving lens 32c toward the subject's eye E, the refractive power can be displaced to the negative side, and by moving the moving lens 32c in the direction away from the subject's eye E, the refractive power can be increased to the positive side. can be displaced. Therefore, by moving the moving lens 32c back and forth, it is possible to change the presentation distance of the optotype displayed on the display 32a, that is, to change the presentation position of the optotype image, and to make the subject's eye E fixed and cloudy. can.

The eye refractive power measurement system 33 includes a ring-shaped light flux projection system 33A that projects a ring-shaped measurement pattern onto the fundus Ef of the eye to be examined E, and a ring that detects (receives) the reflected light of the ring-shaped measurement pattern from the fundus Ef. It has a shaped beam receiving system 33B.

The ring-shaped beam projection system 33A has a reflector light source unit 33a, a relay lens 33b, a pupil ring diaphragm 33c, a field lens 33d, a perforated prism 33e, and a rotary prism 33f. However, the dichroic filter 31b and the objective lens 31a are shared with the observation system 31. FIG. The reflector light source unit 33a has, for example, a reflector measurement light source 33g for reflector measurement using an LED, a collimator lens 33h, a conical prism 33i, and a ring pattern forming plate 33j. It is integrally movable along the optical axis of the measurement system 33 .

The ring-shaped light receiving system 33B has a hole portion 33p of a holed prism 33e, a field lens 33q, a reflecting mirror 33r, a relay lens 33s, a focusing lens 33t, and a reflecting mirror 33u. The filter 31e, the imaging lens 31f, and the imaging device 31g are shared with the observation system 31, the dichroic filter 32i is shared with the target projection system 32, and the rotary prism 33f and perforated prism 33e are shared with the ring-shaped beam projection system 33A. .

Next, the operation in the eye refractive power measurement mode will be described. The controller 26 turns on the reflector measurement light source 33g, and moves the reflector light source unit 33a of the ring-shaped beam projection system 33A and the focusing lens 33t of the ring-shaped beam receiving system 33B in the optical axis direction. In the ring-shaped luminous flux projection system 33A, the reflector light source unit 33a emits a ring-shaped measurement pattern, and the measurement pattern advances to the perforated prism 33e through the relay lens 33b, the pupil ring diaphragm 33c, and the field lens 33d. The light is reflected by the reflecting surface 33v and led to the dichroic filter 32i through the rotary prism 33f. The ring-shaped light beam projection system 33A projects the ring-shaped measurement pattern onto the fundus Ef of the subject's eye E by guiding the measurement pattern to the objective lens 31a through the dichroic filters 32i and 31b.

In the ring-shaped light receiving system 33B, the ring-shaped measurement pattern formed on the fundus oculi Ef is condensed by the objective lens 31a, passed through the dichroic filter 31b, the dichroic filter 32i, and the rotary prism 33f to the hole 33p of the perforated prism 33e. proceed. In the ring-shaped light receiving system 33B, the measurement pattern passes through a field lens 33q, a reflecting mirror 33r, a relay lens 33s, a focusing lens 33t, a reflecting mirror 33u, a dichroic filter 31e, and an imaging lens 31f, and is transferred to an image sensor 31g. form an image. As a result, the image pickup device 31g detects the image of the ring-shaped measurement pattern, and the control unit 26 displays the image of the measurement pattern on the display surface 25a. Based on the image signal from the image (the image pickup device 31g), Spherical power, cylindrical power, and axial angle as eye refractive power are measured by well-known methods.

In the eye refractive power measurement mode, the control unit 26 causes the display 32a of the target projection system 32 to display a fixed fixation target. A luminous flux from the display 32a passes through rotary prisms 32A and 32B, an imaging lens 32b, a moving lens 32c, a relay lens 32d, a field lens 32f, a mirror 32h, a dichroic filter 32i, a dichroic filter 31b, and an objective lens 31a. is projected onto the fundus Ef. The examiner or the control unit 26 performs alignment with the examinee fixating the presented fixed fixation target, and aligns it with the far point of the eye to be examined E based on the results of the temporary measurement of the eye refractive power (ref). After the movable lens 32c is moved, the eye refractive power is measured while the accommodation is in a cloudy state.

The configurations of the eye refractive power measurement system 33, the alignment system 35, the alignment system 36, the keratometry system 37, and the like, and the principles of eye refractive power (refraction), subjective examination, and corneal shape (keratometry) measurement are known. , detailed description is omitted.

[Control system of ophthalmic apparatus]
A functional configuration of the control unit 26 of the ophthalmologic apparatus 10 of the present embodiment will be described with reference to FIG. As shown in FIG. 5, the control unit 26 includes the left-eye measuring optical system 21L, the right-eye measuring optical system 21R, the left-eye vertical driving unit 22L of the left-eye driving mechanism 15L, and the left-eye measuring optical system 22L. horizontal drive unit 23L for left eye, X-direction rotation drive unit 24L for left eye and Y-direction rotation drive unit 25L for left eye, vertical drive unit 22R for right eye, horizontal drive unit 23R for right eye of drive mechanism 15R for right eye, In addition to the right-eye X-direction rotation drive unit 24R and the right-eye Y-direction rotation drive unit 25R, the examiner controller 27, the examinee controller 28, and the storage unit 29 are connected. .

The control unit 26 has an internal memory 26a and a communication unit 26b capable of short-distance wireless communication with the examiner controller 27 and the examinee controller 28 .

The examiner controller 27 includes a display section 30 that is a touch panel display. The display unit 30 includes a display surface 30a on which an image or the like is displayed, and a touch panel type input unit 27a superimposed on the display surface 30a. The controller for examiner 27 displays a predetermined screen on the display surface 30 a based on the display control signal sent from the control section 26 . Further, the examiner controller 27 has a communication section 27b capable of short-distance communication with the control section 26 . The operation input signal received by the input section 27a is sent to the control section 26 via the communication section 27b.

The display unit 30 displays the anterior segment image E′ acquired by the imaging element 31g on the display surface 30a. In addition, the display unit 30 displays fixation targets to be fixated on the left eye EL and the right eye ER. Furthermore, the display section 30 displays the visual axes of the left eye EL and the right eye ER and the optical axis of the measurement optical system 21 on the horizontal or vertical cross section of the left eye EL and the right eye ER. Show diagram. The display unit 30 also displays a schematic diagram showing the positions of the pupil center PC and the corneal reflection Br in the anterior segment image E' on the display surface 30a. The details of the screen displayed on the display surface 30a by the display unit 30 will be described later.

The control unit 26 develops a program stored in the connected storage unit 29 or the built-in internal memory 26a, for example, on a RAM, so as to appropriately respond to the operation of the examinee controller 27 or the examinee controller 28. The operation of the ophthalmologic apparatus 10 is centrally controlled. Further, the control unit 26 functions as a pupil center detection unit 26c, a corneal reflection position detection unit 26d, a rotation angle calculation unit 26e, and a measurement head control unit (drive control unit) 26f. In this embodiment, the internal memory 26a is composed of a RAM or the like, and the storage section 29 is composed of a ROM, an EEPROM, or the like.

The pupil center detection unit 26c detects the left eye EL and the right eye EL from the anterior segment images E' (EL', ER') of the left eye EL and the right eye ER acquired by the imaging element 31g of the observation system 31. The pupil center PC of optometry ER is detected. The corneal reflection position detection unit 26d detects, based on the bright spots Q obtained by imaging the parallel light flux K (see FIG. 7) from the alignment light source 36a of the alignment system 36 in the left eye EL and the right eye ER, The corneal reflections of the left eye EL and the right eye ER, that is, the positions of the bright point images Br, which are the images of the bright points Q, are detected. As shown in FIG. 7, when a parallel light beam K from the alignment light source 36a is incident on the eyeball, a spot-like image (Purkinje image) is formed at a position Q (r/2 of the radius of curvature r of the cornea) inside the cornea Ec. That is, a corneal reflection Br is formed.

The rotation angle calculator 26e calculates the distance _d0 between the pupil center PC and the corneal reflection Br based on the positions of the pupil center PC and the corneal reflection Br of the left eye EL and the right eye ER. Based on the distance _d0 and the radius of curvature r of the cornea, the angle θ between the pupillary axis PX and the optical axis of the measurement optical system 21 is calculated. Calculate _θ1 . This angle _.theta.1 is defined as the angle of rotation of the left and right measuring heads 16L and 16R in the X and Y directions (see FIG. 12). Further, the rotation angle calculation unit 26e calculates the prism base directions and the prism powers of the left eye EL and the right eye ER based on the calculated rotation angles of the left eye EL and the right eye ER, and displays them. You may display on the part 30.

Based on the calculated rotation angle, the measuring head control unit 26f drives the X-direction rotation driving unit 24 or the Y-direction rotation driving unit 25 so that the center of the pupil coincides with the position of the corneal reflection. 16 is rotated in the X direction or the Y direction around the eyeball rotation axes v and h.

Further, in the ophthalmologic apparatus 10 according to the present embodiment, the display unit 30 displays the anterior segment images EL' and ER' of the left eye EL and the right eye ER (see FIG. 15). Therefore, by visually recognizing these, the examiner can grasp the cause of failure in alignment or inspection, for example. In other words, the reasons why alignment etc. cannot be done well include, for example, inability to fixate, inability to see binocularly, strabismus or obliqueness, ptosis, suppression, miosis of the pupil, head part is tilted, etc. By visually recognizing the anterior segment images EL' and ER' of the left eye EL and the right eye ER displayed on the display unit 30 during the execution of the alignment, etc., the examiner can clarify the cause of the inability to perform the alignment, etc. It is possible to comprehend. Then, the position of the head can be corrected, the subject's attention can be urged, countermeasures can be quickly taken, and the success rate of re-alignment and the like can be improved.

(principle)
Next, the measurement principle of the ophthalmologic apparatus 10 according to the present embodiment will be described with reference to FIGS. 6 to 13. FIG.

The ophthalmologic apparatus 10 according to the present embodiment analyzes the anterior segment image E′ of the eye E to be examined, and rotates the measurement head 16 so that the pupil center PC of the pupil image Ep and the bright spot image Br match. It is a device. Furthermore, the ophthalmologic apparatus 10 according to the present embodiment may quantitatively calculate strabismus based on the rotation angle.

Causes of discrepancy between the pupil center PC in the anterior segment image E′ and the bright spot image Br include, for example, strabismus and oblique orientation. Here, strabismus means that the lines of sight of the left eye EL and the right eye ER are directed to different places. If the eye to be examined E does not have strabismus, when the left eye EL and the right eye ER fixate on a common fixation target, the lines of sight of the left eye EL and the right eye ER are at a common location (fixed position) substantially forward. target). However, if the subject eye E has strabismus or the like, the line of sight of one of the left eye EL and the right eye ER does not face the fixation target, and therefore the lines of sight of the left eye EL and the right eye ER are different. head to On the other hand, oblique position means that the lines of sight of the left eye EL and the right eye ER are normally aligned, but when one of the eyes E to be examined is blocked, the line of sight of the blocked eye E is different. facing, also called latent strabismus.

In the ophthalmologic apparatus 10 according to the present embodiment, when the line of sight of either the left eye EL or the right eye ER is not directed to the fixation target due to strabismus or oblique position, the line of sight is directed to the fixation target. After rotating the measuring head 16, inspection such as squint is performed.

FIG. 6 is a horizontal sectional view of the right eye ER viewed from above. In FIG. 6, the left side corresponds to the front and the right side corresponds to the rear. The axis connecting the fixation target (fixation point) at which the right eye ER is fixed and the pupil center PC is the visual axis VX indicating where the right eye ER is looking. On the other hand, the axis extending from the pupil center PC in the direction perpendicular to the cornea Ec is the pupil axis PX indicating the direction in which the right eye ER is facing. Even in the eye E without strabismus, the visual axis VX is slightly deviated to the nasal side (lower in FIG. 6) than the pupillary axis PX. The angle between the visual axis VX and the pupillary axis PX is called the lambda angle (indicated by λ in the figure). Although the lambda angle varies among individuals even in a normal eye E without strabismus, the average value is +5°. When rotating the measuring head 16, it is necessary to rotate at a rotation angle that takes into account the lambda angle λ.

The visual axis VX of the subject's eye E can be known from the position of the bright spot image Br (hereinafter referred to as "corneal reflection Br") based on the alignment light source 36a. Also, the pupillary axis PX of the eye to be examined E can be known from the position of the pupillary center PC. A detailed calculation method of the visual axis VX and the pupillary axis PX will be described later.

FIG. 8 is a diagram showing the positional relationship between the pupil center PC of the pupil and the corneal reflection Br in various perspectives. As shown in FIG. 8, it can be seen that the position of the corneal reflection Br is deviated from the pupil center PC in the eye to be examined E with strabismus (the right eye to be examined ER in the example shown in FIG. 8). Therefore, in the ophthalmologic apparatus 10 according to the present embodiment, the distance d ₀ (deviation amount) between the pupil center PC and the corneal reflection Br is calculated, and based on this distance d ₀ and the radius of curvature r of the cornea, the pupil axis PX and the optical axis of the measurement optical system 21 is calculated (see FIG. 12). Based on this angle θ and the lambda angle λ between the pupillary axis PX and the visual axis VX, the angle _θ1 between the visual axis VX and the optical axis is obtained, and this angle _θ1 is taken as the rotation angle. The measurement head 16 is rotated according to this rotation angle _θ1 to match the pupil center PC and the corneal reflection Br. That is, the visual axis VX of the subject's eye E and the optical axis of the measurement optical system 21 are made to coincide. It is desirable that this match be exact, but rough matching is sufficient, and then fine adjustment can be made by subjective inspection.

In the ophthalmologic apparatus 10 of the present embodiment, for example, the deviation (distance d ₀ ) between the pupil center PC and the corneal reflection Br is obtained based on the Hirschberg method, but the method is not limited to this method. . In the Hirschberg method, a light source is placed at a distance of 33 cm from the subject's eye E, and the subject is instructed to fixate on this light source. and the position of the corneal reflex are measured, and an objective quantitative test is performed.

In the ophthalmologic apparatus 10 according to the present embodiment, the alignment light source 36a that produces the corneal reflection Br and the imaging element 31g of the observation system 31 are on the same optical axis. Therefore, the pupil center PC is determined from the anterior segment image E′ captured by the imaging device 31g, and the position of the corneal reflection Br in the anterior segment image E′ is determined to calculate the rotation angle of the measurement head 16. By rotating the measuring head 16 in accordance with this rotation angle, an objective quantitative inspection of oblique view can be performed according to the Hirschberg method.

FIG. 9 is a diagram showing an example of an anterior eye segment image E′ captured by the imaging device 31g of the observation system 31 in a state in which fixation of a specific viewpoint (fixation point) is instructed. In FIG. 9, Br indicates the corneal reflection, Ep indicates the pupil image, PC indicates the pupil center of the pupil image Ep, and Ir indicates the iris image. FIG. 9(a) is an anterior segment image E' of the subject's eye E without strabismus when an instruction is given to fixate a specific viewpoint (fixation point). As already explained, if the subject's eye E does not have strabismus, the center of the pupil image Ep in the anterior segment image E', that is, the pupil center PC and the corneal reflection Br are at the same position.

On the other hand, FIG. 9(b) is an anterior segment image E' of the subject's eye E with strabismus in a state in which fixation of a specific viewpoint (fixation point) is instructed. The line of sight of the eye to be inspected E with squint does not face the fixation point, and therefore, as already explained, the position of the corneal reflection Br in the anterior segment image E' is deviated from the pupil center PC.

Hereinafter, the non-squint eye E in the state of instructing to fixate the fixation point is the fixation eye or dominant eye, and similarly the eye E with strabismus in the state of instructing to fixate the fixation point is the non-squint eye. It is sometimes called the fixation eye or the non-dominant eye.

In the ophthalmologic apparatus 10 of the present embodiment, the control unit 26 causes the display 32a of the visual target projection system 32 of the ophthalmologic apparatus 10 to display the fixation target. Next, the measurement head control unit 26f of the control unit 26 drives the X-direction rotation drive units 24L and 24R of the drive mechanisms 15L and 15R to move the measurement heads 16L and 16R in the vertical direction of the left eye EL and the right eye ER. The subject is instructed to fixate on a fixation target presented in front of the subject's eye E by rotating it around the extending eyeball rotation axes vL and vR. As a result, the right eye ER and the left eye EL are converged to gaze at the fixation target.

In this state, the pupil center detection unit 26c and the corneal reflection position detection unit 27d of the control unit 26 obtain the pupil center PC and the position of the corneal reflection Br of the pupil image Ep in the anterior segment image E', respectively. Then, the rotation angle calculator 26e calculates the distance between the pupil center PC and the position of the corneal reflection Br based on the positions of the pupil center PC and the corneal reflection Br calculated by the pupil center detector 27c and the corneal reflection position detector 27d. d ₀ (amount of deviation) is calculated, and the angle θ between the pupillary axis PX and the optical axis of the measurement optical system 21 is calculated based on this distance d ₀ and the radius of curvature r of the cornea. Based on this angle θ and the lambda angle λ between the pupillary axis PX and the visual axis VX, the angle _θ1 between the visual axis VX and the optical axis is obtained, and this angle _θ1 is taken as the rotation angle.

Further, the rotation angle calculator 26e calculates a schematic diagram showing the visual axis VX with respect to the anterior segment image E′ and the optical axis (measurement axis) of the measurement optical system 21, and the pupil center PC and the cornea in the anterior segment image E′. A schematic diagram showing the position of the reflection Br is created and displayed on the display surface 30a of the display unit 30 of the controller 27 for examiner.

The relationship of various images displayed on the display unit 30 will be described with reference to FIG. 10 . FIG. 10 shows various images of the subject's eye E in which the left subject's eye EL is squint (see FIG. 8). Images A in FIG. 10 are left and right anterior segment images EL' and ER', and an iris image Ir, a pupil image Ep, the pupil center PC and the corneal reflection Br are observed. This image A shows the positional relationship between the pupil center PC of the pupil image Ep and the corneal reflection Br.

An image B in FIG. 10 is a schematic diagram showing the visual axis VX with respect to the eyes EL and ER to be examined and the optical axis (measurement axis) of the measurement optical system 21 . In the image B, d1 is a horizontal sectional view of the subject's eyes EL and ER, and d2 and d3 schematically show the visual axis VX and the optical axis of the measuring optical system 21, respectively. The visual axis d2 (VX) of the right eye to be examined ER substantially coincides with the optical axis d3. On the other hand, the visual axis d2 (VX) of the left eye EL is tilted with respect to the optical axis d3 and does not match. Note that this image B is an image diagram, and the actual visual axis d2 is shifted by the lambda angle λ.

An image C in FIG. 10 is a schematic diagram showing the positions of the pupil center PC and the corneal reflection Br in the anterior segment images EL' and ER'. The inner circle C1 indicates the edge of the pupil image Ep, and the outer circle C2 indicates the edge of the iris image Ir (cornea Ec). In this image C, the position of the corneal reflection Br is indicated by x. The position of the corneal reflection Br of the anterior segment image ER' of the right eye ER substantially coincides with the center of the pupil center PC. On the other hand, the position of the corneal reflection Br of the anterior segment image EL' of the left eye EL to be examined does not match the pupil center PC. Actually, it reaches the edge of the iris image Ir (cornea Ec).

Furthermore, as shown in the image D of FIG. A schematic diagram may be displayed. As a result, for example, when the subject's eye E is squint upward or squint downward, it becomes easier to grasp the displacement of the visual axis VX in the vertical direction. In the example of FIG. 10, the eyes EL and ER to be examined do not have a vertical squint, so e2 and e3 match.

The method of obtaining the position of the pupil center PC in the anterior segment image E' by the pupil center detection unit 26c may be appropriately selected from well-known methods. As an example, the pupil center detection unit 26c detects the edge of the pupil image Ep from the anterior segment image E' and calculates the boundary coordinates of this pupil image Ep. The edge of the pupil image Ep can be detected, for example, based on the difference in brightness between the pupil Ep and the iris in the anterior segment image E'.

Next, the pupil center detection unit 26c approximates the boundary coordinates of the pupil Ep to an ellipse to calculate the center of the approximate pupil ellipse. First, the pupil center detection unit 27c obtains the coefficients a, b, c, d, and h in the general formula of the ellipse shown in the following formula (1) by the method of least squares from the boundary coordinates of the pupil.

Then, the pupil center detection unit 26c obtains the center coordinates of the approximate pupil ellipse from the coefficients of the ellipse general formula (1) by the following formula (2). The coordinates of the pupil center PC are the coordinates of the center of the approximate pupil ellipse obtained by the following equation (2).

Also, the corneal reflection position detection unit 26d obtains the position coordinates of the corneal reflection Br in the anterior segment image E'. In the ophthalmologic apparatus 10 according to the present embodiment, the alignment light source 36a emits infrared light. Therefore, by extracting only the signal in the infrared region from the output signal of the imaging element 31g, The position of the corneal reflection Br can be obtained easily and accurately.

The rotation angle calculator 26e obtains the displacement amount of the position of the corneal reflection Br with respect to the position of the pupil center PC based on the obtained coordinates of the pupil center PC and the position coordinates of the corneal reflection Br.

For example, it is assumed that the positional coordinates of the pupil center PC and the positional coordinates of the corneal reflection Br shown in the schematic diagram as shown in FIG. 11(a) are obtained. In the example shown in FIG. 11(a), the left eye EL to be examined has an exotropia and a lower oblique. Therefore, as shown in FIG. 11B, the rotation angle calculator 26e calculates a distance dx in the horizontal direction (that is, the X direction) and a distance dx in the vertical direction as the distance between the position of the pupil center PC and the position of the corneal reflection Br. (that is, the Y direction) distance dy is calculated.

Next, the rotation angle calculator 26e calculates the pupil axis PX and the measurement optical system 21 from the distance d ₀ (dx and dy will be described as the distance d ₀ when described without distinguishing between them) and the radius of curvature r of the cornea. Find the angle θ with the optical axis. Based on the angle θ and the lambda angle λ, the angle _θ1 formed between the visual axis VX and the optical axis is obtained, and this angle _θ1 is taken as the rotation angle. FIG. 12(a) shows the position of the bright point Q of the alignment light source 36a in the eye E without strabismus, and FIG. 12(b) shows the position of the bright point Q in the eye E with strabismus. As already explained, the position of the bright point Q is obtained as the position of the corneal reflection Br in the anterior segment image E'.

By the way, the radius of curvature r of the cornea (that is, the distance from the corneal curvature center R0 to the corneal vertex Ept), the distance d between the position of the corneal vertex Ept and the position of the corneal reflection Br, and the pupillary axis PX shown in FIG. and the angle θ formed by the measurement optical system 21 are represented by the following relational expression (3).

sin θ = d/r (3)

The angle θ can be calculated by substituting the distance d and the curvature radius r into the above equation (3). A value obtained by keratometry can be used as the radius of curvature r of the cornea. Alternatively, the average value (7.7 mm) may be used as the initial value for the radius of curvature r of the cornea.

However, in the present embodiment, the displacement amount of the corneal reflection Br with respect to the position of the pupil center PC (distance d ₀ and the distance r ₀ from the corneal curvature center R ₀ to the pupil center PC is used to calculate the following equation (3- 1) is used to obtain the angle θ, which makes it possible to more efficiently calculate the angle θ and the like based on the anterior segment image E′.

sin θ = d ₀ /r ₀ (3-1)

The angle θ can be calculated by substituting the previously obtained distance d ₀ into the above equation (3-1). For the distance _r0 , for example, an average value can be used. Specifically, the distance _r0 is obtained by subtracting the distance r' between the corneal vertex Ept and the pupil center PC from the radius of curvature r of the cornea. If the average value of r = 7.7 mm and the average value of r' = 3.6 mm (however, the average value when the pupil center PC is the front surface of the lens), the distance r ₀ = (7.7-3. 6) mm=4.1 mm.

The positions of the pupil center PC and the corneal reflection Br are easily affected by the refraction action of the cornea, and the distance _r0 varies from person to person. Therefore, the distance d ₀ and the distance r ₀ with respect to the pupillary axis PX of the eye E to be examined without strabismus as shown in FIG. Based on these simultaneous equations, the distance r ₀ may be optimized. Alternatively, the distance r ₀ may be optimized from actual measurements of the radius of curvature r of the cornea obtained by keratometry.

The angle θ can also be calculated by the following equation (4) instead of the calculation procedure using the above (3) or (3-1). In the following equation (4), _L0 indicates the distance from the corneal vertex Ept to the eyeball rotation point O, and D indicates the distance between the position of the corneal vertex Ept and the eyeball rotation point O. Note that the distance _L0 from the corneal vertex Ept to the eyeball rotation point O may be a predetermined value (for example, an average value of 13 mm). Alternatively, if the actual distance is known for measurement by another device, this value may be input. Also in this case, instead of the distance _L0 , the distance from the pupil center PC to the eyeball rotation point O is used, and instead of the distance D, the positions of the pupil center PC and the eyeball rotation point O in the anterior segment image E′ You may calculate using the distance from.

sin θ = D/L ₀ (4)

Furthermore, as a method of calculating the different angle θ, for example, the displacement Δ of the corneal reflection Br (see FIG. 12B) can also be used. The displacement Δ is obtained by fixing the fixation target only on the subject eye E in which displacement has been detected, obtaining each numerical value in the state of FIG. can be represented.

Assuming that the distance from the corneal vertex Ept to the eyeball rotation point O is _L0 and the radius of curvature of the cornea is r, the displacement Δ of the corneal reflection Br shown in FIG. be. Also in this case, the distance _L0 from the corneal vertex Ept to the eyeball rotation point O may be a predetermined value (for example, the average value of 13 mm). Alternatively, if the actual distance is known for measurement by another device, this value may be input. A value obtained by keratometry or an average value (7.7 mm) can be used as the radius of curvature r of the cornea.

Δ=(L ₀ −r)·sin θ (5)

(Operation example of ophthalmologic apparatus)
An example of the operation of the ophthalmologic apparatus 10 of the present embodiment configured as described above will be described with reference to the flowchart of FIG. In the flowchart of FIG. 14, when strabismus is found in any eye E to be examined during binocular eye examination, the position of the measuring head 16 corresponding to this eye E to be examined is rotated to an appropriate position. A case in which objective and subjective examinations of the subject's eye E are performed by the ophthalmologic apparatus 10 will be described later.

First, in step S1, the measurement head control section 26f drives the X-direction rotation driving section 24 to rotate the measurement head 16 in the X direction so that the presentation position of the fixation target is set at a predetermined position. Next, in step S2, the visual target projection system 32 displays a fixation target (for example, a point light source visual target) at the central position of the display 32a. In this state, the examiner instructs the subject to fixate on the fixation target.

In step S3, the imaging elements 31g of the left and right measurement optical systems 21 start photographing the anterior ocular segments of the left and right eyes EL and ER to be examined. As shown in FIG. 15, the control unit 26 displays on the display surface 30a the anterior segment images (frontal images) EL' and ER' of the left and right eyes EL and ER to be examined based on the image signals output from the imaging device 31g. do. The control unit 26 also displays the fixation targets 40R and 40L currently presented by the display 32a on the display surface 30a.

By visually recognizing the anterior segment images EL′ and ER′ displayed on the display unit 30, the examiner can determine whether fixation is appropriate, binocular vision is appropriate, strabismus, oblique position, eyelid ptosis, suppression, miosis of the pupil. , tilt of the head, etc. can be confirmed. As a result, for example, the examiner can take countermeasures such as opening the eyelids by hand for drooping eyelids and alerting the examinee to the inclination of the head.

In step S4, the alignment system 35 performs alignment in the Z direction and the alignment system 36 performs alignment in the X and Y directions by the above-described operations while the subject is fixed on the fixation target.

In step S5, the anterior segment images EL' and ER' are analyzed. That is, the pupil center detector 26c detects the position of the pupil center PC in the anterior segment images EL' and ER', and the corneal reflection position detector 26d detects the position of the corneal reflection Br in the anterior segment image E'. do. Based on the positions of the pupil center PC and the corneal reflection Br, the rotation angle calculator 26e calculates the distance _d0 between the pupil center PC and the corneal reflection Br _. The angle θ formed between the pupil axis PX and the optical axis of the measuring optical system 21 is calculated based on this, and the angle _θ1 formed between the visual axis VX and the optical axis is calculated based on this angle θ and the lambda angle λ. Alternatively, several fixation points may be presented to the subject, subjective judgment may be made as to whether or not the subject is fixating without problems, and the angle _θ1 may be corrected based on this subjective judgment. Also, these average correction values may be implemented.

In step S6, based on the detection results of the pupil center detection unit 26c and the corneal reflection position detection unit 26d, as shown in FIG. Schematic diagrams 41L and 41R showing the optical axis (measurement axis) and schematic diagrams 42L and 42R showing the positions of the pupil center PC and the corneal reflection Br in the anterior segment images EL' and ER' are shown in the anterior segment image EL'. , ER' are displayed on the display surface 30a. Considering the case where the eye E to be examined is oblique upward or oblique downward, a vertical cross-sectional view of the eye E to be examined and the visual axis VX are shown side by side with the schematic diagrams 41L and 41R or instead of the schematic diagrams 41L and 41R. and the optical axis (measurement axis) of the measurement optical system 21 may be displayed (see image D in FIG. 10).

In step S7, based on the distance _d0 or the angle _θ1 calculated in step S5, it is determined whether or not the left and right eyes EL, ER to be examined have strabismus. Specifically, it is determined whether or not the distance _d0 or the angle _θ1 is less than a threshold. Although this threshold can be set arbitrarily, it is preferable to set the threshold of the angle θ ₁ in consideration of the lambda angle (+5°) of the eye E without strabismus.

When the distance _d0 or the angle _θ1 of both the left and right eyes EL and ER to be examined is less than the threshold value, it is determined that the eyes EL and ER to be examined do not have strabismus (NO in step S7), and the objective in step S10 is determined. Proceed to inspection. On the other hand, if the distance _d0 or the angle _θ1 of either the left or right subject eye EL, ER is equal to or greater than the threshold, it is determined that there is strabismus (YES in step S7), and the process proceeds to step S8. In the examples of FIGS. 10 and 15, strabismus is detected in the left eye EL.

In step S8, a predetermined fixation target is presented to the fixation eye without strabismus. At this time, the display 32a is extinguished and the fixation target is not presented to the non-fixation eye determined to have strabismus. However, it is not limited to this, and the same fixation target as the fixation eye may be presented to the non-fixation eye, or the same fixation target may be presented partially.

In step S9, based on the angle θ ₁ (rotational angle) calculated in step S5, the measurement head controller 26f adjusts the measurement head corresponding to the non-fixation eye so that the pupil center PC and the corneal reflection Br match. Rotate 16. When there is a squint in the left-right direction (X direction), the X-direction rotation drive unit 24 is driven to rotate the measurement head 16 in the X direction about the eyeball rotation axis v extending in the vertical direction (FIG. 13A). reference). If there is a squint in the vertical direction (Y direction), the Y direction rotation drive unit 25 is driven to rotate the measurement head 16 in the Y direction around the eyeball rotation axis h extending in the horizontal direction (see FIG. 13 ( b) see).

By the operation of step S9, the pupil center PC and the corneal reflection Br can be matched, and the visual axis VX can be matched with the optical axis of the measurement optical system 21. FIG. After that, the process proceeds to step S10, in response to the selection of the objective examination mode by the examiner (or automatically), eye refractive power (ref) measurement by the eye refractive power measurement system 33, and corneal shape (kerat) measurement by the kerato system 37. Perform objective tests such as

Next, in step S11, a subjective examination of the subject's eye E is performed in response to (or automatically) selection of a subjective examination mode by the examiner. At this time, if strabismus is present, the examiner asks the examinee whether or not the fixation target presented by the target projection system 32 is deviated (blurred) between the right eye ER and the left eye EL. ask whether According to the examinee's response to this question, the examiner operates the input unit 27a of the examiner controller 27 and the like to instruct the rotation of the rotary prisms 32A and 32B. Make fine adjustments to direction and prism power. Then, the degree of strabismus of the left eye EL or the right eye ER when the fixation target is finally shifted and not detected can be obtained as the prism base direction and the prism power.

In this manner, the measuring head 16 is rotated in the X direction or the Y direction to match the visual axis with the optical axis of the measuring optical system 21, corresponding to the oblique eye E, so that the prism base direction And the fine adjustment of the prism power can be performed more quickly and efficiently, and the inspection time of the prism inspection can be shortened. Based on this prism base direction and prism power, distance tests, near vision tests, and other subjective tests can then be quickly performed.

(Modification)
Next, as a modified example, an ophthalmologic apparatus for monocular eye examination will be described. In the above embodiment, the measurement optical system 21 is provided with the target projection system 32 . In this configuration, in the case of monocular eye examination, when the measurement head 16 is rotated while the fixation target on the display 32a is fixated on the eye E with strabismus, the fixation target also moves in the direction of rotation. Therefore, the subject's eye E, which visually recognizes the fixation target, may also rotate accordingly. Therefore, it becomes difficult to match the pupil center PC and the corneal reflection Br.

Therefore, it is desirable that the fixation target does not move when the measurement head 16 is rotated. Therefore, as a modified ophthalmologic apparatus, a target projection system 32 or another target projection system (or a fixation target only) is provided outside the measurement optical system 21, and the measurement head 16 is rotated. The position of the fixation target is fixed without moving the target projection system 32. As a result, only the measuring head 16 can be rotated in accordance with the distance _d0 between the pupil center PC of the eye E to be examined and the corneal reflection Br while the eye E having strabismus is fixed to the fixation target. .

As another modification, the measurement head 16 having the target projection system 32 in the measurement optical system 21 as in the above embodiment may be used, and the display of the fixation target on the display 32a may be appropriately controlled. . When rotating the measuring head 16, the fixation target on the display 32a is moved in the direction opposite to the direction of rotation at a distance and a moving speed corresponding to the amount of rotation and the speed of rotation. With this control, the position of the fixation target is relatively fixed with respect to the subject's eye E, and rotation of the subject's eye E following the rotation of the measurement head 16 can be prevented.

Further, as a different modification, a second target projection system (or a fixation target) that presents a fixation target to an eye E to be examined that is different from the eye E to be examined that faces the measuring head 16 (or a fixation target) is provided in the monocular type eye examination device. mark). In the ophthalmologic apparatus of this configuration, the eye to be examined E to be examined faces the measuring head 16, a fixation target is presented to the eye to be examined E by the target projection system 32, and the second eye E to be examined is not to be examined. The fixation target is presented by the eye target projection system. When strabismus is confirmed in the subject eye E to be examined, the display 32a is turned off to stop presenting the fixation target to this subject eye E (non-fixation eye), and another subject eye E not to be examined. Make only the (fixation eye) fixate the fixation target. By rotating the measuring head 16 in this state, the pupil center PC of the non-fixation eye and the corneal reflection Br can be matched without the non-fixation eye following the rotation.

(Action and effect of optometric device)
The effects of the ophthalmologic apparatus 10 of this embodiment will be described below. The ophthalmologic apparatus 10 of the present embodiment includes a measurement optical system 21 for acquiring information on the subject's eye E to be examined, and a measuring optical system 21 provided in the measurement optical system 21 for measuring the subject's eye E in a state in which a fixation target is presented. An image acquisition unit (image sensor 31g) for acquiring an anterior eye segment image E′ on the optical axis of the optical system 21, and a fixation target for causing the eye E to be examined to fixate the line of sight E. Rotation drive units 24 and 25 (X-direction rotation drive unit 24, A Y-direction rotation drive unit 25) and a pupil center detection unit 26c for detecting the pupil center PC of the eye to be examined E from the anterior ocular segment image E′ of the eye to be examined E acquired by the image acquiring unit while the fixation target is presented. , the corneal reflection Br and a corneal reflection position detection unit 26d that detects the position of the . The rotation driving unit rotates the measurement optical system 21 around the eyeball rotation axis v of the eye E to be examined so that the position of the pupil center PC and the position of the corneal reflection Br are aligned.

With the above configuration, in a state in which a fixation target is presented to the subject's eye E, the corneal reflection is calculated based on the position of the pupil center PC and the position of the corneal reflection Br respectively detected by the pupil center detection unit 26c and the corneal reflection position detection unit 26d. The rotation driving unit rotates the measurement optical system 21 about the eyeball rotation axis v so that the position of Br coincides with the pupil center PC. As a result, even if the eye to be inspected has a squint or an oblique position, the visual axis can be made substantially coincident with the optical axis of the measurement optical system 21 . Therefore, it is possible to provide the ophthalmologic apparatus 10 that can quickly and easily examine strabismus and squint of the subject's eye. As a result, the burden on the subject can be reduced.

Further, in the above embodiment, the rotation angle calculator 26e calculates the distance _d0 between the position of the pupil center PC and the position of the corneal reflection Br, and calculates the rotation angle of the rotation driving unit based on this distance _d0 . and a drive control section (measuring head control section 26f) that drives the rotation drive section to rotate the measurement optical system 21 based on the calculated rotation angle. With this configuration, the line of sight of the subject's eye E and the optical axis can be automatically aligned, and strabismus and oblique orientation of the subject's eye can be inspected more quickly and automatically.

Further, in the above-described embodiment, if the rotation angle calculation unit 26e is configured to calculate the prism base direction and the prism power of the eye to be examined E based on the rotation angle, data for correcting strabismus and obliqueness can be obtained. It can be easily obtained, and the time required for prism inspection can be shortened.

In the above-described embodiment, the rotation drive unit (X-direction rotation drive unit 24) rotates the measurement optical system 21 about the eyeball rotation axis v extending vertically (in the Y direction) through the eyeball rotation point O of the eye E to be examined. It is configured to rotate as an axis. With this configuration, it is possible to rotate the measurement optical system 21 and arrange it at an appropriate position corresponding to the subject's eye E having an esotropia and an exotropia.

In the above embodiment, the rotation drive section (Y-direction rotation drive section 25) moves the measurement optical system 21 along the eyeball rotation axis v passing through the eyeball rotation point O of the eye E to be examined and extending in the horizontal direction (Y direction). It is configured to rotate as a central axis. With this configuration, it is possible to rotate the measurement optical system 21 and arrange it at an appropriate position corresponding to the subject's eye E, which has an upward squint or a downward squint.

In the above-described embodiment, a pair of target projection systems 32 are provided corresponding to the left eye EL and the right eye ER of the subject. A pair of eye target projection systems 32 presents a fixation target to the left eye EL and the right eye ER, and the position of the pupil center PC and the corneal reflex Br are projected to either the left eye EL or the right eye ER. When a positional deviation is detected, the presentation of the fixation target to the eye E (non-fixation eye) in which the deviation is detected is stopped, and the fixation target is presented to the other eye E (fixation eye). is presented, the measurement optical system 21 corresponding to the eye E in which deviation is detected is rotated so that the pupil center PC and the position of the corneal reflection Br are aligned. With this configuration, it is possible to prevent the non-fixation eye from rotating following the rotation of the measurement optical system 21, and to match the positions of the pupil center PC and the corneal reflection Br. A pair of target projection systems 32 are provided corresponding to the left eye EL and the right eye ER of the subject. A visual target is presented, and the subject's eye E in which no deviation is detected between the position of the pupil center PC and the position of the corneal reflection Br is taken as the fixed eye, and the subject's eye E in which the deviation is detected is taken as the non-fixed eye. 216 is rotated so that the pupil center PC and the position of the corneal reflection Br are aligned. With this configuration, it is possible to accurately detect the deviation of the non-fixed eye, and it is possible to accurately perform measurement by matching the position of the pupil center PC and the corneal reflection Br, and calculation of the prism power and the like. .

Further, in the above-described embodiment, the display unit 30 is provided for displaying a schematic diagram showing the positions of the pupil center PC and the point image (corneal reflection Br) in the anterior segment image E'. With this configuration, the examiner can visually and clearly grasp the deviation between the pupil center PC and the corneal reflection Br. Furthermore, a schematic diagram showing the visual axis VX and the optical axis obtained based on the position of the pupil center PC and the point image (corneal reflection Br) on the horizontal or vertical cross section of the eye to be examined E on the display unit 30. is displayed, the examiner can visually grasp the displacement of the visual axis VX with respect to the optical axis.

Further, in the above-described embodiment, by displaying the anterior segment image E' on the display unit 30, the examiner can clearly grasp that the eye E to be examined has strabismus or oblique position. Furthermore, it is possible to grasp whether fixation or binocular vision is appropriate, eyelid ptosis, suppression, miosis of the pupil, inclination of the head, and the like. Therefore, appropriate measures can be taken for alignment and various inspections, and the success rate of alignment and various inspections can be improved.

The ophthalmologic apparatus of the present invention has been described above based on the embodiments, but the specific configuration is not limited to the embodiments, and the invention according to each claim of the scope of claims is not limited to the specific configuration. Design changes and additions are permitted as long as they do not deviate from the gist.

For example, in the above-described embodiment, the rotation angle calculator 26e is provided, and the amount of deviation calculated by the rotation angle calculator 26e is used as the rotation angle. It is automatically rotated in the direction and the Y direction. However, the configuration is not limited to this, and a configuration in which the measurement head 16 is rotated without providing the pupil center detection unit 26c, the corneal reflection position detection unit 26d, and the rotation angle calculation unit 26e may be employed.

That is, as another different embodiment, the measurement optical system 21, the image acquisition section (imaging device 31g), the target projection system 32, and the rotation driving section (X-direction rotation driving section 24, Y-direction rotation driving section 25, ), and the rotation drive unit controls the pupil center PC in the anterior eye segment image E′ acquired by the image acquisition unit while the fixation target is presented, and the pupil center PC in the anterior segment image E′ acquired by the image acquisition unit while the fixation target is presented, The measurement optical system 21 is rotated by rotating the eyeball E to be examined so that the point image (bright point image Br) obtained by forming an image of light rays (parallel beam K) parallel to the optical axis of the eye to be examined coincides with the point image (bright point image Br). It may be configured to rotate with the axis (v, h) as the central axis. With this configuration, the measurement optical system 21 can be easily rotated without detecting the positions of the pupil center PC and the corneal reflection Br of the eye E to be examined.

In this case, for example, an icon for rotating the measuring head 16 vertically and horizontally is displayed on the display surface 30a of the display unit 30 of the examiner controller 27, and by performing a touch operation on each icon, the length of the touch operation (time ), the measuring head controller 26f may drive the driving mechanism 15 to automatically rotate the measuring head 16 in the X direction or the Y direction. Then, while the examiner visually recognizes the anterior segment image E′ and the like displayed on the display unit 30, the measurement head 16 may be rotated by touching the icon so that the point image matches the center of the pupil. . Alternatively, the examiner may grip and rotate the measuring head 16 without depending on the control of the measuring head control section 26f or the touch operation of the icon. As a result, it is possible to omit the step of detecting the positions of the pupil center and the point image and the step of calculating the rotation angle, thereby providing a simpler ophthalmologic apparatus 10 .

Further, as another embodiment, the distance d ₀ (dx and dy) between the pupil center PC of the eye to be examined E and the corneal reflection Br is calculated as a deviation by the arithmetic processing described above, and the measurement head control unit 26f controls the drive mechanism. 15 may be driven to rotate the measuring head 16 to a position that cancels out this deviation. More specifically, while analyzing the anterior segment image E′, the X-direction rotation driving unit 24 is driven to cancel the dx (until dx becomes 0 or equal to or less than the threshold value). The measuring head 16 is rotated in the X direction about the axis V (see FIG. 13(a)). In addition, the Y-direction rotation drive unit 25 is driven to rotate the measurement head 16 in the Y-direction around the horizontally extending eyeball rotation axis h so as to cancel dy (until dy becomes 0 or less than the threshold value). (See FIG. 13(b)). Also with this configuration, the visual axis of the subject's eye E and the optical axis of the measurement optical system 21 can be easily and quickly matched.

Furthermore, as a different embodiment, the control unit 26 detects the rotation angles of the measurement head 16 in the X and Y directions by touch operation or manual operation of the icon, and based on the rotation angles, the prism base direction of the squint eye is detected. and the prism power rhythm may be calculated. With this configuration as well, it is possible to efficiently finely adjust the prism base direction and the prism power rhythm of a strabismus eye, thereby shortening the examination time of the prism examination.

Further, in the above-described embodiment, the imaging device 31g of the observation system 31 is also used as the image acquiring unit for acquiring the anterior segment image E' of the eye E to be examined, but the present invention is not limited to this. As another different embodiment, the image acquisition unit is a photographing unit (camera) in which the anterior segment of the eye E to be inspected is provided separately from the imaging element 31g of the measurement optical system 21, and the direction is different from that of the measurement optical system 21. The anterior segment of the eye may be imaged from the

Specifically, one camera (imaging unit) is arranged in a direction intersecting the measurement optical system 21 (either up, down, left, or right of the optical axis). Image processing such as keystone correction is performed on an anterior segment image E' obtained by photographing the anterior segment from an oblique direction with this camera, and the center of the pupil and corneal reflection are detected.

In addition, such a camera is not limited to one unit, and two or three or more cameras (imaging unit, stereo camera) are provided in front, back, or up and down with the optical axis of the measurement optical system 21 interposed therebetween. may be configured. A stereo camera may be newly provided in the ophthalmologic apparatus 10, or if the ophthalmologic apparatus 10 is equipped with a stereo camera, the stereo camera may also be used as an imaging unit.

Partial images are extracted from a plurality of anterior segment images E′ acquired by such a stereo camera, these are synthesized, image processing such as trapezoidal correction is performed as necessary, and one anterior segment image E is obtained. '. By using the anterior segment image E′ generated by combining in this way, the positions of the center of the pupil and the corneal reflection can be detected with higher accuracy.

As described above, in the configuration in which the anterior segment image E′ is captured by one or more cameras, even when the imaging device 31g of the measurement optical system 21 is positioned conjugate with the fundus, the camera The anterior segment image E' can be obtained by In addition, by displaying the anterior segment image E′ captured by the camera on the display unit 30, the examiner can perform alignment, measurement, etc. while constantly checking the state of the eye E to be examined, thereby avoiding errors and Processing time can be shortened.

10 ophthalmic device 21 measurement optical system 24 X-direction rotating drive unit (rotating drive unit)
25 Y-direction rotation drive unit (rotation drive unit) 26c Pupil center detection unit 26d Corneal reflection position detection unit 26e Rotation angle calculation unit 26f Measurement head control unit (drive control unit) 30 Display unit 31g Image sensor (image acquisition unit) 32 Vision Target projection system Br Corneal reflection E Eye to be examined EL Left eye to be examined ER Right eye to be examined PC Pupil center E′ Anterior segment image O Eyeball rotation point VX Visual axis v Eyeball rotation axis h Eyeball rotation axis

Claims (11)

a measurement optical system for acquiring information about the subject's eye to be examined;
an image acquisition unit provided in the measurement optical system for acquiring an anterior segment image of the eye to be inspected on the optical axis of the measurement optical system;
a target projection system for presenting a fixation target to the eye to be inspected on the optical axis of the measurement optical system for causing the eye to be inspected to fix the line of sight;
a rotation driving unit that rotates the measurement optical system around the eyeball rotation axis of the eye to be inspected;
a pupil center detection unit configured to detect the pupil center of the subject eye from the anterior segment image of the subject eye acquired by the image acquisition unit while the fixation target is presented;
corneal reflection for detecting the position of the corneal reflection of the eye to be examined based on a point image obtained by forming an image in the eye to be examined by light rays parallel to the optical axis incident on the eye to be examined from the measurement optical system; a position detection unit,
The ophthalmologic apparatus, wherein the rotation driving unit rotates the measurement optical system around the eyeball rotation axis of the eye to be inspected so that the pupil center and the corneal reflection position match. a rotation angle calculation unit for calculating the distance between the position of the pupil center and the position of the corneal reflection, and calculating the rotation angle of the rotation driving unit based on this distance; 2. The ophthalmologic apparatus according to claim 1, further comprising a drive control section that drives a rotation drive section to rotate the measurement optical system. 3. The ophthalmologic apparatus according to claim 2, wherein the rotation angle calculator calculates a prism base direction and a prism power of the subject's eye based on the rotation angle. 4. The rotation drive unit rotates the measurement optical system around an eyeball rotation axis extending in the vertical direction passing through the eyeball rotation point of the eye to be inspected. An ophthalmic device as described. 5. The rotation drive unit rotates the measurement optical system about an eyeball rotation axis that extends horizontally and passes through the eyeball rotation point of the eye to be inspected. An ophthalmic device as described. A pair of the eye target projection systems are provided corresponding to the left eye and the right eye of the subject. is presented, and when a deviation is detected between the position of the pupil center and the position of the corneal reflex in either the left eye or the right eye, to the eye where the deviation is detected With the presentation of the fixation target stopped and the fixation target presented to the other eye to be inspected, the measurement optical system corresponding to the eye to be inspected in which the deviation has been detected is positioned between the center of the pupil and the cornea. The ophthalmologic apparatus according to any one of claims 1 to 5, characterized in that it is rotated so that the position of reflection matches. A pair of the eye target projection systems are provided corresponding to the left eye and the right eye of the subject. is presented, and the eye to be examined in which no deviation is detected between the position of the pupil center and the position of the corneal reflex is assumed to be a fixed eye, and the eye to be examined in which the deviation is detected is assumed to be a non-fixed eye. is rotated so that the center of the pupil coincides with the position of the corneal reflex. The ophthalmologic apparatus according to any one of claims 1 to 7, further comprising a display unit for displaying a schematic diagram showing positions of the pupil center and the point image in the anterior segment image. characterized by comprising a display unit for displaying a schematic diagram showing the visual axis and the optical axis obtained based on the positions of the pupil center and the point image on the horizontal or vertical cross section of the eye to be examined. The ophthalmic device according to any one of claims 1 to 8, wherein the The ophthalmologic apparatus according to any one of claims 1 to 9, further comprising a display section for displaying the anterior segment image. 11. The apparatus according to any one of claims 1 to 10, further comprising one or more photographing units for photographing the anterior segment image of the subject's eye from a direction different from the optical axis of the measurement optical system. 10. An ophthalmic device according to claim 1.

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