JP2004201982A - Ophthalmological instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ophthalmological instrument with which an eye to be examined can be observed and photographed under a miosis condition. <P>SOLUTION: The ophthalmological instrument for examining patient's eyes is provided with those right eye illumination means and left eye illumination means each disposed at a position so as to be able to illuminate the eye which is not the object eye to be examined, a right/left detection means for detecting whether the object eye to be examined is right or left, and an illumination switching means for switching the right eye illumination means and the left eye illumination means on the basis of right and left detection signals, in addition, is provided with an observation means for observing the patient's eyes, and an amount of light adjusting means for adjusting amount of illumination light from the illumination means. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ophthalmologic apparatus for examining (observing and photographing) a patient's eye.
[0002]
[Prior art]
2. Description of the Related Art An ophthalmologic apparatus is known in which an anterior segment of a subject's eye is optically cut by slit light and an anterior segment cross-sectional image is obtained by an imaging optical system arranged based on the Scheimpflug principle. According to this device, the angle formed by the posterior surface of the cornea and the anterior surface of the iris of the photographed cross-sectional image can be measured as a corner angle, and glaucoma can be inspected (for example, see Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 1-285241 (pages 2, 3; FIG. 1-3)
[0004]
[Problems to be solved by the invention]
However, there are individual differences in the adjustment of the size of the pupil, and when photographing the corner angle as in the above-described apparatus, there is a case where the iris wrinkles do not extend due to sufficient pupil simply in an environment of indoor lighting. . For this reason, the conventional apparatus has a problem that the inclination angle of the iris surface cannot be determined correctly, and the corner angle cannot be obtained accurately.
[0005]
An object of the present invention is to provide an ophthalmologic apparatus capable of observing and photographing a subject's eye in a state where the subject's eye is constricted.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is characterized by having the following configuration.
[0007]
(1) In an ophthalmologic apparatus for examining a patient's eye, a left eye illumination unit and a right eye illumination unit arranged at positions where the non-examination eye can be illuminated, and whether the examination target eye is left or right is detected. And a lighting switching means for switching between the left eye lighting means and the right eye lighting means based on left and right detection signals.
[0008]
(2) The ophthalmologic apparatus of (1) is characterized by comprising an observation unit for observing a patient's eye, and a light amount adjusting unit for adjusting an illumination light amount of the illumination unit.
[0009]
(3) The ophthalmologic apparatus according to (1), which includes a slit projection optical system that projects slit light onto a patient's eye, and a slit cross-section imaging optical system that has an optical axis inclined with respect to the slit projection optical axis. And a lighting mode selecting means for selecting a corner shooting mode, and a lighting means for lighting the illumination of the lighting means switched by the lighting switching means based on the selection signal of the corner shooting mode. Features.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an external view of an anterior ocular segment photographing apparatus 100 according to the present invention. FIG. 1 (a) is a front view as viewed from the subject, and FIG. 1 (b) is a side view.
[0011]
101 is a measurement unit containing an inspection optical system, 102 is a body unit having a display 55 and operation switches, etc., 103 is a base unit containing a power supply and a horizontal movement mechanism, and 104 is a chin stand for fixing a patient's face. is there. By operating the joystick 40, the body 102 moves in the horizontal direction with respect to the base 103. Reference numeral 32 denotes a micro switch fixed to the body 102, and reference numeral 33 denotes a plate fixed to the base 103. The plate member 33 is mounted on the upper surface of the base portion 103 for the purpose of providing a step, and when the body portion 102 is moved right and left, the micro switch is turned on / off. The ON / OFF of the micro switch 32 detects whether the eye to be inspected is left or right.
[0012]
The measurement unit 101 is provided with illumination LEDs 30a and 30b for illuminating with the amount of light that causes the non-tested eye to pupil. As shown in FIG. 2, the illumination LEDs 30a and 30b are arranged on the left and right with respect to the reference axis L1 of the inspection optical system housed in the measurement unit 101. When inspecting the right eye ER, the front part of the left eye EL is used. When the left eye EL is inspected, the illumination LED 30b is located in front of the right eye ER.
[0013]
FIG. 3 is a diagram illustrating an optical system of the measurement unit 101 of the anterior ocular segment photographing apparatus 100.
[0014]
<Slit projection optical system> 1 is a reflection mirror, 2 is a flash lamp for photography, 3 is a condenser lens, 4 is a slit aperture stop, 5 is a projection lens, and 6 is a reference axis L1 which is an optical axis of the slit projection optical system. It is a dichroic mirror obliquely mounted on the top. The dichroic mirror 6 has a property of transmitting most of visible light and reflecting infrared light.
[0015]
The light emitted from the flash lamp 2 is condensed by the condenser lens 3 and illuminates the slit aperture stop 4. The light flux restricted to a narrow slit shape by the slit aperture stop 4 passes through the light projecting lens 5 and the dichroic mirror 6 and is projected on the eye to be examined. As a result, the light transmitting body (cornea, anterior chamber, crystalline lens, etc.) of the anterior segment of the eye to be examined is illuminated in a light-cut state by a white light source in the visible region.
[0016]
<Slit cross section photographing optical system> L2 indicates a photographing optical axis of the slit cross section photographing optical system. Reference numeral 7 denotes a photographing lens, 8 denotes an anamorphic lens for correcting image distortion, and 9 denotes a CCD camera. The optical axis L2 of the slit cross section photographing optical system is arranged at an inclination angle of 45 degrees with respect to the optical axis L1 of the slit projection optical system. The taking lens 7 is arranged obliquely with respect to the optical axis L2 so as to satisfy the Scheimpflug principle. That is, the line of intersection of the extension of the light cutting of the anterior segment of the eye to be examined by the slit projection light and the extension of the imaging surface 9 a of the CCD camera 9 intersects with the extension of the main plane of the photographing lens 7. With this optical arrangement, the cross-sectional image formed on the imaging surface 9a of the CCD camera 9 can have a depth of focus at which substantially the entire cross-sectional image is focused.
[0017]
<Alignment Target Projection Optical System> 13 is a near-infrared light source for alignment, 14 is a dichroic mirror, and 15 is a projection lens. The light emitted from the light source 13 passes through the dichroic mirror 14, is converted into a parallel light beam by the projection lens 15, and is reflected by the beam splitter 20. Thereafter, the alignment light is reflected by the dichroic mirror 6 toward the eye E along the optical axis L1, and forms a light source image at a position inside the eye by a distance of a half of the corneal curvature radius from the apex of the cornea.
[0018]
<Fixation target presenting optical system> Reference numeral 11 denotes a fixation light source that emits visible light. The light emitted from the light source 11 is projected onto the eye E through a dichroic mirror 14, a projection lens 15, a beam splitter 20, and a dichroic mirror 6.
[0019]
<Anterior Eye Front Imaging Optical System> Reference numeral 21 denotes an imaging lens, and reference numeral 23 denotes a front observation CCD camera having sensitivity in an infrared region. A part of the alignment light beam reflected by the cornea among the alignment light beams projected by the alignment target projection optical system is reflected by the dichroic mirror 6, passes through the beam splitter 20, and is imaged by the imaging lens 21 with the CCD camera 23. The anterior segment image of the eye E illuminated by the anterior segment illumination light source 10 is also captured by the CCD camera 23 through the same optical path.
[0020]
FIG. 4 is a diagram illustrating a configuration of an electric system of the anterior ocular segment photographing apparatus 100 and the image analysis unit 200.
[0021]
<Anterior Eye Section Photographing Unit> The output signal from the CCD camera 9 is digitized by the A / D conversion circuit 50 and is taken into the frame memory 52 in synchronization with the signal of the timing generator 51. The image signal captured by the frame memory 52 is converted to a video signal via a D / A conversion circuit 53 and then sent to an image switching circuit 54. The image switching circuit 54 receives a command signal from the control unit 60, and switches the display image on the display 55 between the captured image from the CCD camera 23 and the captured image from the CCD camera 9. Reference numeral 56 denotes an image synthesizing circuit, which synthesizes various information displays generated by the display circuit 57 with images from the CCD cameras 9 and 23 and displays them on the display 55.
[0022]
The anterior segment cross-sectional image freeze-stored in the frame memory 52 is input to the image transfer switch 63 and transferred to the image analyzer 200 via the interface circuit 64.
[0023]
<Image Analysis Unit> Reference numeral 201 denotes a computer unit that performs image processing on cross-sectional image data input from the anterior ocular segment cross-sectional imaging apparatus 100 and analyzes the image data. The computer unit 201 includes a memory that stores and holds image data and an analysis program for image analysis. Have. A keyboard 202 and a mouse 203 for inputting operation instructions are connected to the computer unit 201. Reference numeral 204 denotes a color display that displays a cross-sectional image and an analysis result input from the anterior ocular segment photographing apparatus 100, and 205 denotes a video printer. The display 204 and the video printer 205 are controlled by the computer unit 201.
[0024]
The operation of the device having the above configuration will be described. First, the examiner presses the mode selection switch 61 provided on the body section 102 to set the corner angle photographing mode. Incidentally, in addition to the corner photographing mode, the present apparatus has a crystalline lens photographing mode for photographing the anterior segment of the eye and photographing the degree of opacity of the crystalline lens. Next, after fixing the patient's head to the chin table 104, the examiner operates the joystick 40 and moves the body part 102 in the left-right direction with respect to the base part 103 so that the optical axis L1 of the measuring unit 101 is aligned with the patient's eye. Move to The microswitch 32 is turned on when measuring the right eye of the patient due to the step between the microswitch 32 and the plate member 33, and is turned off when measuring the left eye. That is, it is detected that the right eye measurement is performed when the micro switch 32 is ON, and the left eye measurement is performed when the micro switch 32 is OFF.
[0025]
The fixation light source 11 is fixed to the patient's eye, and the front image of the subject's eye captured by the CCD camera 23 is sent to the display 55 via the image switching circuit 54. The examiner operates the joystick 40 to measure the eye to be inspected so that the alignment index image projected on the display 55 and the electrically formed reticle image (which may be optically formed) have a predetermined relationship. The alignment is performed by moving the unit 101 up, down, left, and right. Thereby, the optical axis of the optical system of the measurement unit 101 and the eye E can be aligned. Further, the working distance is aligned by moving the measurement unit 101 back and forth so that the alignment index image becomes the smallest and clear image.
[0026]
When the corner shooting mode is set, the control unit 60 illuminates the non-test target eye with the illumination LEDs 30a and 30b based on the mode selection signal and the signal from the microswitch 32. That is, when the micro switch 32 is ON, the control unit 60 turns on the illumination LED 30b because the right eye measurement is performed, and when the micro switch 32 is OFF, the control unit 60 turns on the illumination LED 30a because the left eye measurement is performed. In addition, the examiner observes the degree of opening of the pupil of the anterior ocular segment image displayed on the display 55, and operates the light amount adjustment knob 65 so that the pupil is miotic within a range where the patient does not complain of pain of glare. The light amount of the illumination LED 30a or the illumination LED 30b is adjusted. When the non-test target eye is illuminated by the illumination LEDs 30a and 30b, the non-test target eye becomes miotic. In conjunction with this, the test target eye also becomes miotic.
[0027]
When the preparation for the above-mentioned imaging is completed, the examiner presses the imaging switch 62 to turn on the flash lamp 2, and the CCD camera 9 photographs the anterior ocular segment cross-section image light-cut by the slit light. Since the corner photographing mode is set, the control unit 60 turns on the flash lamp 2 with a lower light quantity than in the crystal photographing mode. In lens photography, it is necessary to increase the amount of illumination because scattered light from a transparent body is taken, but in corner photography, if the amount of reflected light from the iris is too large because the iris is not a transparent body, the inclination angle of the iris surface can be determined. It is difficult to analyze, so the amount of light is reduced to prevent this.
[0028]
The captured image is stored in the frame memory 52, and the display image on the display 55 is switched from the observation image to display the captured image. The anterior ocular segment image stored in the frame memory 52 is transferred to the image analyzer 200 by pressing the image transfer switch 63.
[0029]
Next, the examiner measures a corner angle from the anterior segment cross-sectional image obtained using the image analysis unit 200. The image transferred from the anterior ocular segment photographing apparatus 100 is taken into a frame memory of the computer unit 201. The image captured in the frame memory is displayed on the color display 204. The examiner operates the mouse 203 as shown in FIG. 5 to measure the corner angle. First, as shown in FIG. 5A, a straight line La is drawn by the mouse 203 so as to match the surface of the iris of the anterior ocular segment image. Next, as shown in FIG. 5B, 3 to 10 points P are designated over the entire posterior surface of the cornea. Thereafter, the computer unit 201 draws a quadratic curve C by least squares approximation based on the designated point P as shown in FIG. 5C, and a tangent Lc and a straight line at the intersection of the quadratic curve C and the straight line La. The angle A at which La intersects is determined as a corner angle. The corner angle A is displayed as APPARENT ANGLE at the lower right of the screen as shown in FIG. Since the eye to be inspected is also miotic in conjunction with the miosis of the eye not to be inspected, the inclination angle of the iris surface shown in FIG. 5A can be determined correctly, and the corner angle can be determined accurately. be able to.
[0030]
In the above embodiment, the illumination LEDs 30a and 30b are used as the illumination light sources for miosis of the non-test target eye. However, the illumination light sources are not limited to LEDs, and may be other types such as lamps and EL (Electro Luminescence) that emits planar light. It may be an illumination light source.
[0031]
Further, in the above embodiment, an anterior ocular segment photographing apparatus is described as an example of the ophthalmologic apparatus, but the present invention is not limited to this, and the other eye different from the target observation or examination eye is used. To adjust the size of the pupil by illuminating the pupil.
[0032]
【The invention's effect】
As described above, according to the present invention, it is possible to adjust the size of the pupil of the subject's eye to observe and photograph the subject's eye. In addition, the burden on the examiner can be reduced.
[Brief description of the drawings]
FIG. 1 is an external view of an anterior ocular segment photographing apparatus.
FIG. 2 is a diagram showing an arrangement of illumination LEDs.
FIG. 3 is a diagram showing an optical system of the anterior ocular segment photographing apparatus;
FIG. 4 is a control system configuration diagram of an anterior ocular segment photographing apparatus and an image analysis unit;
FIG. 5 is a view showing a photographed anterior ocular segment image.
[Explanation of symbols]
2 Flash lamp 3 Condenser lens 4 Slit aperture stop 7 Shooting lens 8 Anamorphic lens 9 CCD camera 23 CCD camera 30a Illumination LED
30b Lighting LED
Reference Signs List 32 Micro switch 33 Board material 55 Display 60 Control unit 65 Light amount adjustment knob 100 Anterior ocular segment photographing device

Claims (3)

In an ophthalmologic apparatus for examining a patient's eye, left-eye illumination means and right-eye illumination means arranged at positions where the non-examination eye can be illuminated, and left / right detection for detecting whether the examination target eye is left or right And an illumination switching means for switching between the left eye illumination means and the right eye illumination means based on left and right detection signals. The ophthalmologic apparatus according to claim 1, further comprising: an observation unit that observes a patient's eye; and a light amount adjustment unit that adjusts an illumination light amount of the illumination unit. The ophthalmologic apparatus according to claim 1 is an anterior ocular segment imaging apparatus including a slit projection optical system that projects slit light onto a patient's eye, and a slit cross-section imaging optical system that has an optical axis inclined with respect to the slit projection optical axis, A photographing mode selecting unit for selecting a corner photographing mode; and a lighting unit for lighting the illumination of the lighting unit switched by the lighting switching unit based on the selection signal of the corner photographing mode. Ophthalmic equipment.

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