JP2003265514A - Cornea surgical equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide cornea surgical equipment by which cornea surgery is more accurately carried out. <P>SOLUTION: This cornea surgical equipment applies laser beam to the cornea and changes the surface shape of the cornea based on refractivity data of the cornea. The cornea surgical equipment is provided with an image pickup optical system for pickuping an anterior section image of an eye to be placed in a state for carrying out operation, a mark inspection means which inspects from the image pickupped by the image pickup optical system, marks having a predetermined relation with a predetermined reference direction and formed preliminarily in the eye to be operated in a position where measurement data to be a factor for deciding refractivity data of the cornea is obtained, and an inspection means for obtaining information on rotational deviation to the reference direction based on inspection result. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corneal surgery device that changes the surface shape of the cornea by excising the cornea.

[0002]

2. Description of the Related Art There is known a corneal surgery device for correcting a refractive error of the eye by ablating the cornea by irradiating a laser beam and changing the shape of the corneal surface. In this type of surgery, the characteristics such as the corneal shape and refractive power distribution (or wavefront aberration distribution) of the preoperative eye are measured,
Corneal ablation data is calculated based on the measured data.

[0003]

However, the posture during the measurement of eye characteristics as described above is usually in the standing position (the state where the patient's face is upright), whereas the posture during corneal surgery is Is performed in a lying position on the bed. It is known that eyeball rotation occurs in the recumbent position with respect to the standing position, and depending on the patient, there are cases where the eyeball rotates by 5 degrees or more. In the conventional corneal surgery, there is a problem that the rotation of the eyeball due to the difference in the body position cannot be fully considered.

In view of the above-mentioned prior art, it is an object of the present invention to provide a corneal surgery apparatus which can perform corneal surgery with higher accuracy.

[0005]

In order to solve the above problems, the present invention is characterized by having the following configuration. (1) An imaging optical system that captures an anterior ocular segment image of a surgical eye placed in a surgical operation in a corneal surgery device that irradiates the cornea with a corneal ablation data based on corneal ablation data to change the corneal surface shape. , A mark that is pre-applied to the surgical eye placed in the posture of the body when obtaining measurement data that is a factor in determining corneal ablation data, and that has a predetermined relationship with a predetermined reference direction. It is characterized by comprising mark detecting means for detecting from an image picked up by the image pickup optical system, and rotational deviation detecting means for obtaining information on rotational deviation of the eye with respect to the reference direction based on the detection result. (2) The corneal surgery device according to (1) is characterized by including a correction unit that corrects corneal ablation data based on the rotational displacement information. (3) The corneal surgery device according to (1) is characterized by having display means for displaying the rotational deviation information. (4) The corneal surgery apparatus according to (1) includes a bed for placing the patient in a supine state during surgery, and a rotating means for relatively rotating the bed or the laser beam based on the rotation deviation information. Characterize. (5) The corneal surgery device according to (1), the head fixing means for placing the operating eye in the body position when obtaining the measurement data, and the marking unit for attaching the mark to the operating eye fixed by the head fixing means. And are provided.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the configuration of a corneal surgery device system according to the present invention. Reference numeral 1 is an ophthalmologic measuring device for measuring the corneal shape and refractive power distribution, and 200 is a corneal surgery device for irradiating a laser beam to a patient's eye (operative eye). The ophthalmologic measuring apparatus 1 obtains measurement data of the corneal shape and refractive power distribution that are factors that determine the corneal ablation amount, and then calculates the ablation amount data based on the measurement data. The ablation amount data is transferred to the computer 209 of the corneal surgery apparatus 200 via wired communication or an electronic recording medium.

FIG. 1 shows a side external view of the ophthalmologic measuring apparatus 1. A head support portion 2 for fixing the head of the subject is fixed to the fixed base 1a. The measurement is performed with the face of the patient standing vertically on the head support 2. Reference numeral 5 denotes a measurement unit that houses a measurement optical system, an alignment optical system, and the like. The main body 3 on which the measurement unit 5 is mounted moves forward and backward and left and right on the fixed base 1a by tilting the joystick 4 forward and backward and left and right. Further, by rotating the rotary knob 4a provided on the joystick 4, a vertical drive mechanism including a motor or the like operates, and the measuring unit 5 is connected to the main body 3
Move up and down against. 6 is a color monitor,
Information about the eye to be inspected for observation, alignment information, and notification information to the examiner such as measurement results is displayed.

FIG. 2 is a block diagram showing the configuration of the measurement system and control system of the ophthalmologic measuring apparatus 1. Reference numeral 10 denotes a corneal shape measuring system, which has an optical system for projecting a Placido ring, which is a large number of ring indices, onto the cornea of a patient's eye, and an optical system for capturing a Placido ring image projected on the cornea, and processes the image. The edge of the ring image is detected to obtain the corneal curvature distribution. Reference numeral 11 denotes an eye-refractive-power distribution measuring system, which is symmetrical with an optical system that scans a slit light beam on the fundus of the patient's eye and a meridian corresponding to the slit direction of the slit light with the optical axis sandwiched at a position substantially conjugate with the patient's cornea. And a function of calculating the refractive power of the patient's eye that changes in the meridian direction based on the phase difference signal of each of the light receiving elements.

Reference numeral 15 is an ablation amount analysis unit. The analyzing unit 15 may be a personal computer independent of the ophthalmologic measuring apparatus 1. The analysis unit 15 obtains ablation amount data for refractive surgery from the eye refractive power distribution data and the corneal curvature distribution data input from the measurement systems 10 and 11. In that method, the data of the eye refractive power distribution is converted into the refractive power at the corneal position, and the refractive power required to bring the eye to be examined into emmetropia is obtained in the form of corneal refractive power. Then, the refractive power distribution data is converted into corneal curvature distribution data using Snell's law, and the three-dimensional shape data thereof is obtained. And give the data of the surgery area,
The ablation amount is calculated by subtracting the 3D shape data obtained from the refractive power distribution measurement from the 3D shape of the preoperative cornea obtained from the corneal shape measurement. This ablation amount data is obtained by dividing it into a spherical component (rotationally symmetric component), a cylindrical surface component (axisymmetric component), and an asymmetric component.
Each ablation amount is graphically displayed in a three-dimensional shape such as a bird's-eye view.

The details of the configuration of the cornea shape measuring system 10 and the eye refractive power distribution measuring system 11 and the analyzing method of the analyzing unit 15 are described in Japanese Patent Application Laid-Open No. 11-342152 by the present applicant. Please refer to. The ablation amount data obtained by the analysis unit 15 is transferred to the corneal surgery apparatus 200 side by the communication unit 16 that communicates by wire or wirelessly (flexible disk or the like). The ophthalmologic measuring apparatus 1 calculates the refractive power distribution, but it may measure the wavefront aberration distribution (measurement shown in USP. 6,086,204). The ablation amount data is obtained from the wavefront aberration data, but it is more accurate to obtain it by combining the measurement data of the cornea shape.

FIG. 3 is a view for explaining an apparatus for applying a mark for detecting the rotational deviation of the eyeball to the patient's eye. In FIG. 3, the slit lamp 100 is attached to the marking unit 110.
Is attached. The slit lamp 100 includes a head support portion 102 fixedly mounted on a fixed base 101, and, like the ophthalmologic measuring apparatus 1, observes the patient's eyes with the patient's face standing vertically. The marking unit 110 includes a holding case 111 attached to the upper part of the microscope section 103, a slide shaft 113 held by the holding case 111 so as to be movable back and forth, and an arm 115 rotating about the slide shaft 113. And a marking part 120 attached to the arm 115 and a lever 117 for moving the marking part 120 back and forth.

As shown in FIG. 4, the marking portion 120 has three marking members 123a, 12a on the support base 121.
3b and 123c are attached. FIG. 4A is a front view of the marking unit 120 as viewed from the patient's eye side, and FIG. 4B is a view of the marking unit 120 as viewed from above. In FIG. 4A viewed from the front, the marking members 123a, 123
b has a horizontally long rectangular shape in the horizontal direction, and the marking member 123c has a horizontally long rectangular shape in the vertical direction. The axis H passing through the centers of the marking members 123a and 123b is the horizontal reference. The marking member 123c is arranged above the centers of the marking members 123a and 123b. The three marking members are arranged in the vicinity of the corneal limbus of the eyeball of the patient's eye at intervals to mark. The position is preferably a position avoiding the corneal resection region and a position on the sclera, for example, 11 to 13 mm. Further, it is preferable that the positions of the three marking members can be adjusted. Further, the tip of each marking member is inclined so as to follow the curve of the eyeball (see FIG. 4B). With this marking member, as shown in FIG.
The patient eye has three marks 123Ma, 123Mb, 12
3Mc is attached. The shape of the mark is not limited to the above, and may be a dot shape. In the case of a dot shape, in order to facilitate the identification of the mark, it is advisable to have a configuration in which several points are continuously arranged instead of the rectangular mark.

The mark on the eyeball is preferably a dye that is easily visible, and typically methylene blue can be used. In patients with a blue iris, the red dye is preferred. As the red dye, for example, food red, a red solution for toothpaste inspection used in dentistry, and the like can be used. The marking member consists of a slightly soft felt and is impregnated with ink of such pigment. Ink may be impregnated immediately before the mark is attached, or a structure in which an ink bottle is provided inside the support base 121 may be used.

Next, the structure of the corneal surgery device 200 will be described. FIG. 6 is a schematic external view of the corneal surgery device 200, and FIG. 7 is a diagram showing the configuration of an optical system and a control system. Surgical device body 20
Laser light from an excimer laser light source 210 arranged inside 1 is guided to an arm portion 202 through an optical system such as a mirror. The arm portion 202 has the X direction and the Y direction in FIG.
It can move in any direction. The arm tip portion 205 is movable in the Z direction. Movement in each direction is performed by drive units 251, 252, 253 including a motor and a slide mechanism. A controller 206 is provided with a joystick and various switches. Reference numeral 209 is a computer for inputting various data of necessary surgical conditions, calculating, displaying and storing laser irradiation control data. A color monitor 275 displays an observation image of the patient's eye. 290 is a bed for the patient, who undergoes surgery in a recumbent position. The patient's eye is placed under the microscope of the microscope unit 203 attached to the arm tip 205. Also, bet 29
0 can be rotated in the horizontal direction by the bed rotating mechanism 291.

In FIG. 7, the laser beam emitted from the laser light source 210 in the horizontal direction is a mirror 211, 21.
2 and is further reflected by the plane mirror 213 in the direction of 90 degrees. The plane mirror 213 is a mirror drive unit 21.
4, the laser beam can be moved in the direction of the arrow in the figure, and the laser beam can be moved in parallel in the Gaussian distribution direction to uniformly ablate the object. This point is described in detail in JP-A-4-242644, so please refer to it in detail.

An image rotator 215 is rotationally driven by an image rotator drive unit 216 about a central optical axis to rotate a laser beam around the optical axis. 217 is a mirror. Reference numeral 218 denotes a variable circular aperture that limits the ablation region to a circular shape, and the aperture diameter is changed by the aperture driving unit 219. 22
Reference numeral 0 denotes a variable slit aperture that limits the ablation region to a slit shape, and the aperture driving unit 221 can change the opening width and the slit opening direction. 22
Reference numerals 2, 223 are mirrors that change the direction of the beam. 22
4 is a circular aperture 218 and a slit aperture 2
20 is a projection lens for projecting 20 onto the cornea Ec of the patient's eye.

A split aperture plate 260 having a plurality of circular small apertures is removably disposed in the optical path between the slit aperture 220 and the mirror 222. The split aperture plate 260 is combined with the split shutter 265 to selectively split the laser beam in the longitudinal direction. By selectively opening and closing the circular small aperture of the split aperture plate 260 by the shutter plate of the split shutter 265, the rectangular laser beam can be selectively split in the longitudinal direction for irradiation. The split aperture plate 260 and the split shutter 265 are movable by a drive unit 268 within a plane perpendicular to the laser optical axis.

Reference numeral 225 is a dichroic mirror having a characteristic of reflecting an 193 nm excimer laser beam and passing visible light and infrared light. The laser beam passing through the projection lens 224 is 90 ° by the dichroic mirror 225.
It is deflected and guided to the cornea Ec. A fixation lamp 226 and an objective lens 22 are provided above the dichroic mirror 225.
7. A dichroic mirror 230 that reflects infrared light and transmits visible light and a microscope unit 203 are arranged. The operated eye is illuminated by the visible light source 247, and the operator observes the operated eye with the microscope unit 203. In the optical path on the reflection side of the dichroic mirror 230, an imaging lens 231 and an infrared transmission filter 2 are provided.
35 and a CCD camera 233 are sequentially arranged. CC
The D camera 233 images the anterior segment illuminated by the infrared light source 246 and constitutes a pupil position detection system. CCD camera 23
The output of 3 is connected to the pupil position detection unit 243.
L indicates the reference axis of laser irradiation.

A mirror 270 is disposed at a position above the dichroic mirror 230 and between the binocular optical paths of the microscope section 203 (on the optical axis of the objective lens 227), and the reflection side of the mirror 270. Imaging lens 2 in the optical path
71, a CCD camera 273 for visible image capturing is arranged. The camera 273 captures the anterior segment image illuminated by the visible light source 247. The output of the camera 273 is output by the image control unit 274.
It is connected to the. The image control unit 274 detects the mark attached to the patient's eye by image processing, obtains the position of the mark, and projects the anterior segment image on the color monitor 275.
A graphic is composite-displayed on the anterior segment image.

Next, the operation of the system having the above configuration will be described. First, the ophthalmologic measuring apparatus 1 measures the corneal shape and the refractive power distribution, which are factors that determine the amount of corneal ablation. At the time of measurement, the head of the patient is fixed by the head support 2 so that both eyes of the patient are in a horizontal state. The patient's face is in a standing position. After the alignment between the patient's eye and the measurement optical system is completed and each measurement is performed, the analysis unit 15 is instructed to obtain the excision amount data. The obtained ablation amount data is transferred to the corneal surgery device 200 side.

Before the operation, the slit lamp 100 is used.
After observing the patient's eye with, the marking unit 110 is used to mark the eyeball of the patient's eye for rotation correction. At this time, as in the case of the ophthalmologic measuring apparatus 1,
The head of the patient is fixed by the head support 102 so that both eyes of the patient are in a horizontal state. The marking part 120 at the retracted position (the position indicated by the dotted line in FIG. 3) is rotated and placed in front of the patient's eye. The lever 117 is operated to operate the marking portion 12
0 is moved forward to move the three marking members 123a, 123
The eyeball of the patient's eye is marked with b and 123c. In addition, by providing the marking unit 110 in the ophthalmologic measuring apparatus 1, it is possible to add a mark in the state at the time of measurement. As shown in FIG. 5, the patient's eye has three marks 123M.
a, 123Mb, 123Mc are attached.

After the marking is made, the patient is placed on the bed 290 on the side of the corneal surgery apparatus 200, and the arm tip portion 205 is moved to position the surgical eye under the microscope portion 203. The operator observes the surgical eye with the microscopic unit 203, and aligns the reticle center observed in the microscope unit 203 with the pupil center of the surgical eye. This alignment can be automatically performed by operating the pupil position detection unit 234. The control unit 250, based on the detection signal from the pupil position detection unit 234, drives the units 251, 252, 253.
To move the arm unit 202 (for details of eyeball position detection and alignment control, see Japanese Patent Laid-Open No. 9-149914). In addition, when the operation eye can be observed by the microscope unit 203, the anterior segment image of the operation eye is captured by the CCD camera 273.
And the image signal is input to the image control unit 274.

FIG. 8 shows an example of an image taken by the CCD camera 273 and displayed on the monitor 275. On the screen,
A horizontal reference line 300 indicating the horizontal reference direction of laser irradiation is graphically displayed. Since the image is captured in color, the three colored marks 123Ma, 123Mb, 1
23 Mc can be observed. Mark 123 positioned linearly
Since Ma and 123Mb are attached in the horizontal direction in the standing position, by comparing with the horizontal reference line 300, it can be seen that the eyeball is rotating (rotational deviation), and the surgery is performed depending on the position of the mark 123Mc. You can see the upper and lower parts of the eye (upper and lower eyelid direction). Three marks 123Ma, 123M
Since the positional relationship between b and 123 Mc and the shape of each mark are known in advance, the image control unit 274 distinguishes the images of these marks from the eye pattern such as the iris and performs image processing to detect them. When the images of these marks can be detected, a line segment 302 passing through the centers of the marks 123Ma and 123Mb arranged in a straight line is calculated, and the line segment 302 and the horizontal reference line 30 are calculated.
An angle θ1 formed by 0 and 0 is obtained. This causes a rotational shift due to the difference in body position.

Using the detection information of the rotational deviation θ1, the correction of the eyeball rotation during laser irradiation is performed as follows. Marks 123Ma, 1 are displayed on the screen of the monitor 275.
A line segment 302 connecting 23 Mb is displayed graphically. The surgeon moves the face position of the patient and rotates the surgical eye to superimpose the graphic line of the line segment 302 on the graphic line of the horizontal reference line 300. The image control unit 274 uses the marks 123Ma and 123M.
b, 123Mc is detected continuously or intermittently,
If the rotational deviation θ1 falls within the allowable range, the operator is informed of the completion of the correction by changing the display form such as thickening the graphic line of the line segment 302 as the completion of the correction.

It should be noted that the graphic display of the horizontal reference line 300 and the line segment 302 is preferably composed so that the luminous flux of the display and the observation light are combined so that the microscope section 203 can observe it. This allows the surgeon to observe the line segment 30 while observing under the microscope.
The graphic display of 2 makes it possible to know the alignment state. In addition, such eye rotation alignment information may be obtained by simply displaying the angle of the rotation deviation θ1 as a numerical value. At the time of alignment, the angle value is adjusted to 0.

Corrective surgery by laser irradiation will be briefly described. Here, it is assumed that myopia is corrected. When ablating the spherical component, the control unit 250 limits the laser beam by the circular aperture 218 and sequentially moves the plane mirror 213 to move the laser beam in the Gaussian distribution direction. Then, each time the laser beam finishes moving on one surface, the moving direction of the laser beam is changed by the rotation of the image rotator 215 (for example, three directions at 120 degree intervals), and the area limited by the circular aperture 218 is substantially removed. Ablate evenly. By performing this each time the size of the opening area of the circular aperture 218 is sequentially changed, it is possible to perform ablation of the spherical component in which the central portion of the cornea is deep and the peripheral portion is shallow.

When ablating the pillar surface, the control unit 2
Reference numeral 50 designates the size of the opening area of the circular aperture 218 so as to match the optical zone, and fixes it.
The opening width of 20 is changed. Further, the slit aperture 220 is adjusted in advance by the drive unit 221 so that the slit opening width changes in the strong main meridian direction. As in the case of the spherical component described above, the irradiation of the laser beam is performed by sequentially moving the plane mirror 213 to move the laser beam in the Gaussian distribution direction, and by rotating the image rotator 215 every time the laser beam is scanned. By changing the moving direction of the beam, the area limited by the slit aperture 220 is ablated substantially uniformly. Then, by repeating this while sequentially changing the opening width of the slit aperture 220, the ablation of the cylindrical surface component can be performed.

In the case of ablating a partial asymmetric component, the split aperture plate 260 is arranged in the optical path, the position of the circular small aperture of the split aperture plate 260 is adjusted based on the ablation data of the asymmetric component, and the split shutter 265 is used. The circular small aperture is selectively opened / closed by driving the. By scanning the laser beam due to the movement of the plane mirror 213, only the laser beam in a small area passing through the opened circular small aperture is irradiated onto the cornea. The amount of ablation at each position is controlled by controlling the irradiation time. This allows ablation of asymmetric components.

The correction of the eyeball rotation can also be performed by a method of correcting the input ablation amount data without moving the operated eye. The data of the rotational deviation θ1 is sent to the computer 209, and the computer 209 converts the ablation amount data into the ablation amount data rotated by the rotational deviation θ1. Based on this, each drive unit is controlled as described above to perform laser irradiation.

Further, instead of rotating the ablation amount data, a method of rotating the laser beam irradiating the cornea by the laser irradiation optical system by the rotational deviation θ1 may be used. For example, in the optical system shown in FIG. 7, an image rotator for beam rotation is arranged in the optical path from the split aperture plate 260 to the dichroic mirror 225. Then, if the beam is rotated by this image rotator by the amount of rotational deviation θ1, ablation in which the eyeball rotation is corrected can be performed.

When the refraction correction is performed only by the ablation of the spherical surface component and the cylindrical surface component, it is the cylindrical surface component that needs to be rotated. Therefore, the slit opening direction of the slit aperture 220 is corrected by the rotational deviation θ1. It may be controlled to. Furthermore, as another method, the rotational deviation θ
The controller 250 may control the bet rotating mechanism 291 to rotate the bet 290 based on the data No. 1. In this case, if the bed 290 is rotated around the center of both eyes of the patient, the movement of the arm 202 can be reduced.

[0032]

As described above, according to the present invention,
It is possible to correct the rotational deviation of the eyeball due to the difference in body position, and to perform corneal surgery with higher accuracy.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a corneal surgery device system according to the present invention.

FIG. 2 is a configuration block diagram of a measurement system and a control system of the ophthalmologic measuring apparatus.

FIG. 3 is a diagram illustrating an apparatus that applies a mark for detecting a rotational deviation of an eyeball to a patient's eye.

FIG. 4 is a diagram illustrating a configuration of a marking unit included in a marking unit.

FIG. 5 is a diagram showing a state of marks attached to a patient's eye.

FIG. 6 is a schematic external view of a corneal surgery device.

FIG. 7 is a diagram showing a configuration of an optical system and a control system of the corneal surgery device.

FIG. 8 is a diagram showing an example of an anterior segment image captured during surgery.

[Explanation of symbols]

1 Ophthalmic measuring device 2 head support 15 Ablation amount analysis unit 110 marking unit 123Ma, 123Mb, 123Mc mark 200 corneal surgery device 209 computer 250 control unit 273 CCD camera 274 Image control unit 275 color monitor 290 bets

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2F065 AA03 AA20 AA39 AA46 AA53                       BB07 BB27 CC16 EE00 FF41                       GG04 GG21 HH07 HH12 HH13                       JJ03 JJ09 JJ26 LL12 LL13                       LL20 LL26 LL28 LL30 LL50                       PP13 SS02 SS13 TT02

Claims (5)

[Claims] 1. An imaging optics for capturing an anterior ocular segment image of a surgical eye placed in a surgical operation in a corneal surgery device that changes a corneal surface shape by irradiating a cornea with a laser beam based on corneal ablation data. A mark that is attached in advance to the system and the surgical eye that is placed in the body position when obtaining measurement data that is a factor that determines corneal ablation data, and has a predetermined relationship with a predetermined reference direction. A cornea comprising: a mark detecting unit that detects a mark from an image captured by the imaging optical system; and a rotational displacement detecting unit that obtains rotational displacement information of the eye with respect to the reference direction based on the detection result. Surgical equipment. 2. The corneal surgery apparatus according to claim 1, further comprising a correction unit that corrects corneal ablation data based on the rotational displacement information. 3. The corneal surgery device according to claim 1, further comprising display means for displaying the rotational displacement information. 4. The corneal surgery apparatus according to claim 1, further comprising a bed for placing the patient in a supine state during surgery, and a rotating means for relatively rotating the bed or the laser beam based on the rotational deviation information. A corneal surgery device characterized by the above. 5. The corneal surgery apparatus according to claim 1, further comprising a head fixing means for placing an operating eye in a body position when obtaining measurement data.
A corneal surgery device comprising: a marking unit that attaches the mark to the surgical eye fixed by the head fixing means.