JP2003024367A - Cornea operation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cornea operation device capable of forming a thin, stable and good flap. SOLUTION: The cornea operation device for cut-opening a cornea in the state of layers is provided with a suction means for sucking air in a clearance formed between a patient's eye and a suction ring, a varying means for varying suction pressure in the clearance, a pressure detector for detecting the suction pressure in the clearance, an input means for measuring the intraocular pressure of the patient's eye to which the suction ring is fixed by the suction means by a measuring unit of the intraocular pressure and inputting the result of measuring and a control unit for controlling the varying means so as to make the intraocular pressure value in an expected range based on the result of measuring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corneal surgery apparatus for making a layered incision on the cornea of a patient's eye during corneal refractive surgery.

[0002]

2. Description of the Related Art In recent years, for corneal refractive surgery, flaps are formed by making a layered incision at a thickness of about 0.15 mm from the corneal epithelium to the parenchyma, leaving one end (hinge) of the cornea. LASIK surgery (Laser in Situ Keratomileusis), in which the parenchyma is ablated by a corrective refraction amount by an excimer laser beam and the flap is returned again, is attracting attention. In this LASIK operation, a microkeratome (Microk
A corneal surgery device called eratome) is used.

As a microkeratome, a suction ring is adsorbed and fixed from the corneal limbus to the surface of the conjunctiva, the cornea is pressed flatly by a corneal pressing member, and the blade is laterally vibrated to move in the hinge direction. It is known to make a layered incision with a uniform thickness.

[0004]

However, when the suction ring is adsorbed when the flap is created, the intraocular pressure of the patient's eye rises, but in the past, the suction force applied to the suction ring was constant. There was a problem when the thickness of the incised flap changed due to the difference in If the intraocular pressure is high, the flap becomes thick, and if the flap is made too thick, swelling of the excised part (Ectasia) tends to appear after refractive surgery with excimer laser light. Further, if the intraocular pressure is too low, button holes and the like are likely to occur in the flap, and it is difficult to form a good flap.

The present invention has been made in view of the above problems of the conventional device.
It is a technical object to provide a corneal surgery device capable of forming a thin and stable flap.

[0006]

In order to solve the above problems, the present invention is characterized by having the following configuration.

(1) In a corneal surgery device for cutting a cornea in layers, a suction means for sucking air in a space formed between a patient's eye and a suction ring, and a variable means for varying suction pressure in the space. A pressure detector for detecting the suction pressure in the space, and an input means for measuring the intraocular pressure of the patient eye whose suction ring is fixed by the suction means by an intraocular pressure measurement unit, and inputting the measurement result, And a control unit for controlling the variable means so as to obtain an intraocular pressure value in a desired range based on the measurement result. (2) In the corneal surgery device according to (1), the variable means is a speed control device that changes the rotation speed of the motor of the suction means.

(3) In the corneal surgery device of (1),
The intraocular pressure measurement unit includes a gas pressure generation unit that applies a gas pressure to the patient's cornea through a chamber provided in the probe and a piston held by the probe, and a gas pressure detector that detects the pressure in the chamber. The gas pressure applied to the cornea and the intraocular pressure of the patient's eye are in equilibrium, and the equilibrium pressure is measured by the gas pressure detector to measure the intraocular pressure. (4) In the corneal surgery device according to (1), the intraocular pressure measurement unit includes an applanator that applanates the cornea and a pusher that detects a pressing force of the applanator when the cornea is in a predetermined applanation state. A pressure detector is provided, and the intraocular pressure of the patient's eye is measured based on the output of the pressing force detector.

(5) In the corneal surgery device of (1),
The input unit inputs the intraocular pressure value measured at least twice when the suction pressure is changed by the variable unit, and the control unit controls the intraocular pressure value in a desired range based on the input intraocular pressure value. It is characterized in that it comprises a calculating means for obtaining the suction pressure. (6) In the corneal surgery device according to (1), the control unit has a memory that stores the correspondence between the intraocular pressure value and the suction pressure.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view and a control system schematic view of a corneal surgery device according to the present invention.

Reference numeral 1 is a main body of the microkeratome, and 1a
Is a gripping part that a surgeon grips during surgery. On the front side (left side in the figure) of the main body 1, a suction part 3 for fixing to the patient's eye, and a cutting part 2 having a blade 20 (described later) for cutting the cornea to move straight on the suction part 3.
And are provided.

A feed motor 11 for moving the cutting portion 2 straight in the cutting direction and a vibration motor 12 for giving a lateral vibration to the blade 20 are fixedly provided in the main body 1. A feed screw 13 having a screw portion for moving the cutting portion 2 in a straight line is connected to a rotation shaft of the feed motor 11. A mounting member 14 is screwed onto the feed screw 13, and the vibration motor 12 is mounted on the mounting member 14.
And the connecting member 17 to which the cutting portion 2 is connected are fixed. The forward / reverse rotation of the feed motor 11 causes the vibration motor 12 via the feed screw 13 and the mounting member 14.
And the connecting member 17 moves back and forth, which causes the cutting portion 2 to move back and forth. The connecting member 17 also serves as a bearing for the rotary shaft 15, and holds the rotary shaft 15 rotatably. An eccentric shaft 16 is implanted at the tip of the rotary shaft 15 at a position deviated from the center of rotation, and the eccentric shaft 16 imparts lateral vibration to the blade 20.

The structures of the cutting portion 2 and the suction portion 3 will be described with reference to FIGS. 2, 3 and 4. FIG. 2 is an enlarged view of FIG. 1 regarding the cutting portion 2 and the suction portion 3. 3 is a sectional view taken along line AA of FIG. 2, and FIG. 4 is a sectional view taken along line BB of FIG.

The cutting unit 2 has a blade 20 for cutting the cornea, a blade holder 21a and a holder block 21b for holding the blade 20 in a laterally oscillating manner.
A first vibration transmission member 22 for transmitting the lateral vibration generated by the eccentric shaft 16 to the blade 20, and a second vibration transmission member 22 for transmitting the lateral vibration by the first vibration transmission member 22 to the blade 20.
The vibration transmitting member 23 and the cornea holding portion 24 fixed to the holder block 21b by the mounting member 24a are included. A rotation hole into which the rotation shaft 15 is inserted is provided inside the holder block 21b, and the tip of the connecting member 17 is fixed.

As the blade 20, a metal blade using stainless steel, steel or the like for the cutting edge or a mineral blade using minerals such as diamond or sapphire for the cutting edge is used, and the blade holder 21 at an appropriate angle with respect to the horizontal plane.
It is held so as to be capable of lateral vibration between a and the holder block 21b. The blade 2 is on the blade holder 21a side.
A shallow recess 210a is formed in the portion where 0 is placed, and the width of the recess 210a is larger than the vibration width of the blade 20 due to the lateral vibration.

The first vibration transmission member 22 is movable laterally in a receiving groove 210c formed in the holder block 21b. The first vibration transmission member 22 is held by the holder block 21b in the upward and downward directions. The first vibration transmission member 22 is formed with a vertical groove 22a that engages with the eccentric shaft 16, and the vibration motor 1
When the rotary shaft 15 is rotated by the rotational drive of 2,
A lateral kinetic force is applied to the first vibration transmission member 22 by the circumferential movement of the eccentric shaft 16 engaged with the vertical groove 22a.
As a result, the first vibration transmission member 22 vibrates laterally.

The second vibration transmitting member 23 is movable laterally in the receiving groove 210b formed in the holder block 21b. The second vibration transmitting member 23 is held by the holder block 21b in the upper direction and the blade holder 21a in the lower direction. The first vibration transmitting member 22 is provided below with a convex portion 22b protruding toward the blade 20 side, and the second vibration transmitting member 23 is formed with a vertical groove 23a which engages with the convex portion 22b. There is.
When the first vibration transmission member 22 laterally vibrates due to the rotation of the rotary shaft 15 (the circumferential movement of the eccentric shaft 16), the second vibration transmission member 23 is further laterally vibrated by the lateral vibration of the convex portion 22b engaged with the vertical groove 23a. Exercise power is added. As a result, the second vibration transmission member 23 laterally vibrates, and the blade 20 fixed to the second vibration transmission member 23 laterally vibrates.

The cornea holding portion 24 is provided on the front side (left side in FIG. 2) of the blade 20 and flattens the cornea of the patient's eye as the cutting portion 2 advances, prior to the incision by the blade 20. The blade 20 incises the cornea that is flatly pressed by the corneal pressing portion 24, so that a layered flap is formed.

The distance between the cutting edge of the blade 20 attached to the blade holder 21a and the lower surface of the corneal pressing portion 24 is set to about 0.15 mm so that the upper portion of the cornea can be incised in layers with this thickness.

The suction portion 3 is composed of a fixing member 30, a suction ring 31, a suction pipe 32, etc. The suction ring 31 is fixed to the main body 1 by the fixing member 30. The suction ring 31 has a generally U-shaped cross section, and has a circular recess 31a for contacting the patient's eye and an opening 31b concentric with the recess 31a. There is. During the operation, when the suction ring 31 is installed in the patient's eye, the patient's cornea projects upward from the opening 31b, and the lower end of the suction ring 31 and the open end of the opening 31b are brought into contact with the patient's eye. A space S for suction is secured by the contact.

The suction pipe 32 is planted in the suction ring 31 and is connected to a vacuum tube 34a, and the vacuum tube 34a is connected to the pump 4.
It has been extended to 1 (see Fig. 1). Suction pipe 3
The suction passage 32a provided inside 2 communicates with the recess 31a, and the suction ring 31 is suction-fixed to the patient's eye by sucking and discharging the air in the space S via the suction passage 32a by the pump 41. At the time of this fixing, the operator holds the gripping portion 1a so that the opening 3
The position of 1b can be easily determined and the device can be held stably. Further, by adsorbing the suction ring 31 to the patient's eye, the intraocular pressure of the patient's eye rises, and even when the cornea is held by the cornea retainer 24, the cornea is cut without escaping from the blade 20.

The pump 41 has a motor 41a whose rotation speed is variable, and the suction pressure can be arbitrarily changed by controlling the rotation speed of the motor 41a. Further, the suction pressure may be arbitrarily changed by rotating the pump speed at a constant speed and providing an electromagnetic valve between the suction ring 31 and the pump 41 to adjust the leak amount of the electromagnetic valve.

A tube 34b is connected in the middle of the vacuum tube 34a, and the tube 34b is connected to the pressure sensor 33. The pressure sensor 33 detects the suction pressure sucked by the pump 41.

In FIG. 1, 5 is an intraocular pressure measuring unit for measuring the intraocular pressure of the patient's eye. The tonometry unit 5 of the embodiment shown in FIG. 1 is a pneumatic tonometer (Pneumatic Ap).
Planation Tonometer) is used, and its schematic configuration is shown in FIG. In addition, this type of tonometer
See 3714819 for more details.

The probe 50 held by the operator has a hollow piston 52 and a tip 53 attached to the tip of the piston 52, and the piston 52 is held so as to be movable in its axial direction. Freon gas is made to flow from the gas cylinder 61 into the flow path 55 formed in the probe 50 at a constant rate. Part of the gas reduces friction of movement of the piston 52 through the air bearing 51, and part of the gas passes from the chamber 56 formed in the probe 50 through the hollow portion 52a of the piston 52 to the tip 53. The structure is such that it goes and escapes from the hole 53a to the atmosphere. The chamber 56 communicates with the pressure sensor 62. A silicon rubber film 54 is stretched at the tip of the tip 53, and when this is brought into contact with the cornea, the silicon rubber film 54 becomes convex inside the tip 53 according to the shape of the cornea, and suppresses gas outflow into the atmosphere. When the internal pressure of the chamber 56 rises, it gradually flattens the cornea, and at the point when equilibrium is reached, the gas flows out into the atmosphere. The pressure in the chamber 56 at this point is the pressure sensor 62.
Detected by.

The pressure sensor 62 is connected to the control unit 60 of the intraocular pressure measurement unit 5, and the control unit 60 converts the output signal of the pressure sensor 62 into intraocular pressure. Incidentally, 63 is a measurement switch of the intraocular pressure measurement unit 5, preferably a foot switch.

The intraocular pressure data obtained by the control unit 60 of the intraocular pressure measurement unit 5 is input to the main control unit 40 which controls the microkeratome main body 1 side according to an instruction from the control unit 60.
In addition, the main controller 40 includes an operation panel 8 for setting an intraocular pressure value during surgery, a memory 9 for storing data, an alarm 46 for making an alarm sound, and a foot switch 42 (suction pump 41).
An operation switch 42a, a switch 42b for starting the feeding operation and the vibration operation of the blade 20, and a switch 42c for returning the cutting portion 2) are provided, a pump 41, and a pressure sensor 33 are connected.

In the device having the above-mentioned structure,
The operation will be described below. Before surgery,
The operator sets the desired intraocular pressure value during the incision operation to the U of the operation panel 8.
The P button 8a and the DOWN button 8b are set.
The set value at this time is displayed on the preset display portion 8c.

The operator uses the suction ring 31 based on the mark previously made on the cornea of the patient's eye with an instrument such as a marker.
While confirming the tilted state of (main body 1) and the position of the center of the pupil, the center of the opening 31b is positioned with respect to the center of the pupil and the suction ring 31 is placed on the patient's eye. Also,
The tip 53 of the probe 50 of the intraocular pressure measurement unit 5 is placed on the upper cornea of the patient's eye, and the measurement switch 63 is pressed to prepare for intraocular pressure measurement.

After the suction ring 31 is installed, the operator operates the pump 41 by stepping on the switch 42a of the foot switch 42 while keeping the position and posture of the main body 1 to operate the suction ring 31 and the patient's eye. The air in the space S between them is sucked, and the air pressure is reduced (toward negative pressure). Further, the operator gently presses the tip 53 so that it comes into contact with the corneal surface, and measures the intraocular pressure. The intraocular pressure data sequentially and continuously obtained by the control unit 60 of the intraocular pressure measurement unit 50 is input to the main control unit 40, and the intraocular pressure value is displayed on the measured intraocular pressure display unit 8d on the operation panel 8.

When the air pressure in the space S between the suction ring 31 and the patient's eye is lowered, the eye pressure of the patient's eye rises accordingly. The intraocular pressure data sequentially and continuously (or intermittently at predetermined sampling times) input from the tonometry unit 5 side by the control unit 60 is monitored by the main control unit 40, and the intraocular pressure data is displayed on the operation panel 8. The motor 41a of the pump 41 is controlled by the main control unit 40 so that the intraocular pressure value set in advance is set (including the case where an allowable range is provided).
Drive is controlled. The main controller 40 may directly obtain the output signal of the pressure sensor 62 on the tonometry unit 5 to control the drive of the pump 41 based on the relationship between the output signal and the set intraocular pressure value. In addition, the suction ring 31 and the pump 4
In the case of the training in which the solenoid valve is provided between 1, the main controller 40 controls the leak amount of the solenoid valve.

When the set intraocular pressure value is reached, the suction pressure in the suction ring 31 detected by the pressure sensor 33 is stored in the memory 9. Then, during the operation of corneal incision, the main control unit 40 holds the suction pressure,
The rotation speed of the motor 41a that drives the pump 41 is controlled.

When the set intraocular pressure value is reached, the main control section 40 informs the operator of the fact that the set intraocular pressure value has been reached by the alarm 46. When the operator knows that the set intraocular pressure value has been reached, the operator removes the intraocular pressure measurement probe 50 from the patient's eye and moves to the corneal incision. The operator presses the switch 42b of the foot switch 42 to rotationally drive the feed motor 11 and the vibration motor 12 respectively. The main controller 40 receives the drive instruction signal from the switch 42b to control the rotation of the vibration motor 12 so that the blade 20 laterally vibrates, and also controls the rotation of the feed motor 11 to hinge the cutting unit 2. Move straight in the direction. At this time,
The rotating shaft 15 slides in the traveling direction together with the cutting portion 2 while performing a rotating operation for imparting a lateral vibration to the blade 20.

By sliding the blade 20, the upper part of the cornea is incised to form a flap. The thickness of the flap is determined by the distance between the cutting edge of the blade 20 and the lower surface of the corneal pressing portion 24, but the thickness also depends on the fluctuation of the intraocular pressure. Usually, when the intraocular pressure is high, the flap thickness is thick, and when the intraocular pressure is low, the flap thickness is thin. In this device, the air pressure in the space S during the operation is controlled by the main control unit 40 so that the intraocular pressure value is set in advance, so that a good flap thickness intended by the operator can be stably obtained. .

When the tip of the blade 20 is incised leaving the hinge portion and the formation of the flap is completed, the switch 42c is pressed to reversely rotate the feed motor 11 to return the cutting portion 2 to the initial position. At this time, the blades 20 are pulled out from the flaps while avoiding unnecessary vibration of the blades 20 by controlling each motor separately, such as stopping the rotation of the vibration motors 12.

After the cutting portion 2 is returned to the initial position, the driving of the pump 41 is stopped to allow the air to flow into the space S, the suction ring 31 is released from the suction, and the microkeratome body 1 is removed. Then, the laser beam is used to perform substantial ablation with the corrective refractive power, and the flap is returned to complete the operation.

In the above embodiment, an example using the pneumatic tonometry unit capable of continuously or intermittently obtaining the eye pressure was described, but the present invention is not limited to this, and various types can be used. For example, it is possible to configure the present invention by using a type in which the cornea is pressed by an applanator and the intraocular pressure is measured each time from the pressing force of the applanator when the cornea is in a predetermined applanation state. is there.

FIG. 6 is a schematic structural view for explaining an example of the intraocular pressure measuring unit 5 '. A contact guide 102 is formed at the tip of the probe 100, and an applanator for applanating the cornea at the center thereof. 101 is provided. At the time of measuring the intraocular pressure, the tip end surface of the contact guide 102 is brought into contact with the tip end surface of the applanator 101. A strain plate 103 is fixed to the rear part of the applanator 101, and a strain gauge 10 attached to the strain plate 103 is provided.
The output of 5 is input to the control unit 110. The control unit 110 obtains the intraocular pressure by obtaining the pressing force applied to the applanator 101 from the output of the strain gauge 105. Reference numeral 106 is a measurement switch.

This tonometry unit 5'is a Mackay-Mar
The one using the measurement principle of the tonometer of g
No. 2-122632), and its measurement principle will be briefly described based on FIG. 7. As the cornea on the spherical surface is applanated by the applanator 101, the force applied to the applanator 101 increases to P1 at which the applanation area of the cornea is equal to the area of the contact surface of the applanator 101, and the applanation is further performed. Applanation area is applanator 10
When the area of the contact surface of No. 1 is exceeded, the peripheral contact guide 102
The cornea comes into contact with the skin, and the force due to the rigidity of the cornea is applied to the contact guide 10.
The force applied to the applanator 101 by being dispersed into two is reduced. At this time, a downward peak P2 is formed in the waveform of FIG. 7 showing the relationship between the applanation amount and the force. At the descent point P2 at the top of the peak, it is considered that the force due to the rigidity of the cornea is completely dispersed in the base, and the value at this descent point P2 is converted into intraocular pressure.

Since such an intraocular pressure measuring unit 5'does not continuously measure with the passage of time, the main control section 40 controls the pump 41 as follows so that the intraocular pressure value is set in advance.

The intraocular pressure increased by driving the pump 41 is repeatedly measured by the intraocular pressure measuring unit 5 '. The main control unit 40 stores the intraocular pressure value obtained by repeated measurement and the suction pressure data output from the pressure sensor 33 at the time when the measurement value is obtained in the memory 9 in association with each other. Then, as shown in FIG. 8, the set intraocular pressure values EP of at least two locations or more
Eye pressure value EP1 lower than 0 and suction pressure BP1 at that time, eye pressure value EP2 higher than set eye pressure value EP0 and suction pressure B at that time
If P2 is obtained, both measured values EP1 and E for EP0
The suction pressure BP that should be the set intraocular pressure value EP0 from the ratio of P2
0 is obtained. The main controller 40 drives and controls the pump 41 so that the suction pressure BP0 obtained by the calculation is obtained. Further, when the suction pressure BP0 is detected by the pressure sensor 33, the operator is notified by the alarm 46. As a result, similarly to the previous example, the corneal incision can be performed while maintaining the suction force so as to obtain the desired intraocular pressure value.

In the case of this type of intraocular pressure measurement,
The main controller 40 measures the intraocular pressure at the suction pressure BP0 again, and if the intraocular pressure value and the set intraocular pressure value are out of the allowable range, the result of the remeasurement is further taken into consideration for suctioning. The pressure may be corrected.

[0043]

As described above, according to the present invention,
A thin and stable flap can be formed.
As a result, Ectasia can be suppressed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a device body of the present embodiment and a schematic view of a control system.

FIG. 2 is an enlarged explanatory view of a cutting unit and a suction unit.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a sectional view taken along line BB of FIG.

FIG. 5 is a diagram illustrating a schematic configuration of an intraocular pressure measurement unit.

FIG. 6 is a schematic configuration diagram illustrating another example of the intraocular pressure measurement unit.

FIG. 7 is a diagram illustrating a measurement principle of the intraocular pressure measurement unit of FIG.

FIG. 8 is a diagram illustrating a contrast relationship between intraocular pressure fluctuation and suction pressure fluctuation.

[Explanation of symbols]

1 Microkeratome body 2 cutting section 3 Suction section 5 Intraocular pressure measurement unit 5'Intraocular pressure measurement unit 9 memory 31 Suction ring 33 Pressure sensor 40 Main control unit 41 pumps 41a motor 60 control 61 gas cylinder 62 Pressure sensor

Claims (6)

[Claims] 1. A corneal surgery device for cutting a cornea in layers, comprising: suction means for sucking air in a space formed between a patient's eye and a suction ring; and variable means for varying suction pressure in the space. A pressure detector for detecting a suction pressure in the space, an intraocular pressure measuring unit for measuring an intraocular pressure of a patient eye having a suction ring fixed by the suction means, and an input means for inputting the measurement result, A corneal surgery device comprising: a control unit that controls the variable means so that the intraocular pressure value falls within a desired range based on the measurement result. 2. The corneal surgery device according to claim 1, wherein the variable means is a speed control device that changes a rotation speed of a motor of the suction means. 3. The corneal surgery apparatus according to claim 1, wherein the intraocular pressure measurement unit includes gas pressure generating means for applying a gas pressure to the cornea of the patient's eye through a chamber provided in the probe and a piston held by the probe, A gas pressure detector for detecting the pressure in the chamber is provided, and the gas pressure applied to the cornea and the ocular pressure of the patient's eye are brought into equilibrium, and the equilibrium pressure is detected by the gas pressure detector. A corneal surgery device characterized by measuring the. 4. The corneal surgery apparatus according to claim 1, wherein the intraocular pressure measurement unit detects an applanator that applanates the cornea and a pressing force of the applanator when the cornea is in a predetermined applanation state. And a pressing force detector for measuring the intraocular pressure of the patient's eye based on the output of the pressing force detector. 5. The corneal surgery device according to claim 1, wherein the input unit inputs an intraocular pressure value measured at least twice when the suction pressure is changed by the variable unit, and the control unit is input. A corneal surgery apparatus comprising: a calculation unit that calculates a suction pressure that is an intraocular pressure value in a desired range based on the intraocular pressure value. 6. The corneal surgery device according to claim 1, wherein the control unit has a memory that stores a correspondence between an intraocular pressure value and a suction pressure.