JPH08103414A - Ophthalmological device - Google Patents

Abstract

PURPOSE: To facilitate the alignment of the arbitrary section of the patient's eye by providing the above device with a position stopping means for detecting the cornea reflected light of a projecting optical system for projecting a lumi nous flux for alignment to the cornea of the eye to be examined from two directions and determining the three-dimensional positions for the eye to be examined in accordance with the result of the detection. CONSTITUTION: Of the light reflected by the cornea surface, the alignment light reflected by the corner near the vertex of the cornea is transmitted through a half mirror 7 and an imaging lens 8 and is reflected by a dichroic mirror 9 when a spot light source 6 for alignment is lighted and the cornea is irradiated with the alignment light. The reflected light thereof images a bright spot on two-dimensional CCDs 13 through a diaphragm 12. The alignment light reflected in the peripheral part of the cornea surface passes the imaging lens 14 and the diaphragm 15 and forms the bright spot on two-dimensional CCDs 16. The positions of the respective bright points are, thereupon, detected in an image processing circuit 23. the positions in vertical and lateral directions of the device with respect to the eye to be examined and in the axial position of the eye to be examined are calculated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ophthalmologic apparatus, and more particularly to an alignment system for performing alignment with a site in the eye.

[0002]

Alignment in conventional ophthalmic devices involves aligning the device's axis with respect to the patient's eye, particularly the visual axis, and setting a given working distance between the patient's eye and the device. That is, the conventional alignment uniquely assumes the position of the device with respect to the patient's eye and places the device within a tolerance with respect to the patient's eye.

[0003]

However, with the above-mentioned device, it is impossible to set a measurement site (or a treatment site) at an arbitrary position in the eye. For example, a device for measuring the opacity of the crystalline lens. Also in, the measurement site cannot be set to multiple desired sites. Also, if the device is placed within tolerance to the patient's eye, the deviation will be ignored,
Since the reproducibility of the measurement site cannot be obtained sufficiently, the measurement error due to the difference of the measurement site cannot be eliminated. Therefore, the reliability is remarkably lacking even when measuring and observing with time. The present invention has been devised in view of the above drawbacks, and can be aligned with any part of the patient's eye,
It is a technical subject to provide an ophthalmologic apparatus having good reproducibility even in measurement over time.

[0004]

The present invention has the following features in order to achieve the above object. (1) In an ophthalmologic apparatus that aligns a desired portion in the eye and inspects the eye to be inspected by an inspection means, an observation optical system for observing the anterior segment of the eye to be inspected and a light flux for alignment are projected on the cornea of the eye to be inspected. A projection optical system that emits light, a detection optical system for detecting corneal reflected light from the projection optical system from two directions, and a position for obtaining a three-dimensional position with respect to the eye to be inspected based on the detection result of the detection optical system. A calculation means; a signal generation means for generating a signal for executing an examination of the eye to be inspected; and a holding means for storing and holding a three-dimensional position with respect to the eye to be inspected when the signal is generated by the signal generation means together with an examination record. Is characterized by.

(2) The light projecting optical system of (1) is characterized in that the light beam is projected onto the cornea of the eye to be examined via a member for reflecting the light beam for alignment arranged in the observation optical system.

(3) The observation optical system of (1) has a two-dimensional image pickup device and a display for displaying an image picked up by the image pickup device, and the two-dimensional image pickup device is one of the detection elements of the detection optical system. It is characterized in that it is also used as one.

(4) The ophthalmologic apparatus of (1) includes a laser projecting optical system for projecting laser light onto the eye lens to be inspected and a laser scattered light detecting optical system for detecting scattered light of the projected laser light. It is characterized by having.

(5) The laser projecting optical system and the laser scattered light detecting optical system of (4) are characterized by having an optical axis symmetrical with respect to the optical axis of the observation optical system.

(6) In an ophthalmologic apparatus for inspecting the eye to be inspected by the inspection means by aligning a desired portion in the eye, an observation optical system for observing the anterior segment of the eye to be inspected, and a light beam for alignment to the eye to be inspected. A projection optical system for projecting light onto the cornea, a detection optical system for detecting corneal reflected light by the projection optical system from two directions, and a three-dimensional position with respect to the eye to be inspected based on the detection result of the detection optical system. A position calculating means for determining the position of the eye to be inspected; It is characterized by having.

[0010]

Embodiment 1 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an outline of an apparatus for measuring the opacity of a crystalline lens as an example. Reference numeral 1 is a laser light source for projecting laser light onto a crystalline lens, 2 is an expander lens, 3 is a condenser lens, and 1 to 3 constitute a laser projection optical system for measuring turbidity. Reference numeral 4 is an eye to be inspected, and 5 is a lens. 6 is a point light source for fixation and alignment, 7 is a half mirror, and 6 and 7 are an alignment projection optical system for projecting an alignment light beam onto an eye to be examined. Reference numerals 8 to 11 constitute a laser scattered light detection optical system that detects scattered light of the laser light by the crystalline lens. 8 is an imaging lens, 9 is a dichroic mirror that transmits laser light, 10 is an aperture,
Reference numeral 11 is a photodetector.

Reference numeral 12 is a diaphragm, 13 is a two-dimensional CCD,
The dichroic mirror 9 is arranged at a position branched from the laser scattered light detection optical system. 8, 9, 12 and 13 form a first alignment detection optical system. 14 is an imaging lens, 15 is a diaphragm, 16 is a two-dimensional CCD,
14-16 comprises a 2nd alignment detection optical system.
The optical axis of the second alignment detection optical system intersects the optical axis of the laser scattered light detection optical system at a predetermined angle. The signals from the light receiver 11 and the two-dimensional CCDs 13 and 16 are subjected to predetermined processing and input to the arithmetic / control circuit 17. Reference numeral 18 is a storage means for storing the coordinates and the like of the measurement site. Reference numeral 19 is an input means such as a patient's ID number and measurement date, and 20 is an XYZ drive means for moving the optical system in a three-dimensional direction with respect to the eye to be examined. Reference numeral 21 is an image composition circuit, and 22 is a television monitor.
Reference numeral 23 is an image processing circuit.

Next, the operation of the above apparatus will be described.
First, the alignment point light source 6 is turned on, and the cornea is irradiated with alignment light via the half mirror 7. The light reflected on the surface of the cornea enters the first and second alignment detection optical systems, respectively. The image information from the two-dimensional CCDs 13 and 16 is displayed on the television monitor 22 via the image synthesizing circuit 21. FIG. 2 shows an example of the display. The left half screen 30 shows the image of the first alignment detection optical system, and the right half screen 31 shows the image of the second alignment detection optical system. The bright spots 32 and 33 on both screens represent the corneal reflection bright spots of the alignment light, and are aligned in advance so that bright spots 32 and 33 having a brightness higher than a predetermined reference are obtained on the screen.

In the first alignment detection optical system, the alignment light reflected by the cornea near the apex of the cornea passes through the half mirror 7, passes through the imaging lens 8, and then is reflected by the dichroic mirror 9. The alignment light that has passed through the diaphragm 12 forms a bright spot, which is a cornea reflection image of the alignment light, on the two-dimensional CCD 13. The position of the bright spot 32 is detected by the image processing circuit 23, and the position of the device in the vertical and horizontal directions with respect to the subject's eye is obtained. Further, the alignment light reflected by the peripheral portion of the corneal surface enters the second alignment detection optical system. The alignment light passes through the imaging lens 14 and the diaphragm 15, and then forms a bright spot on the two-dimensional CCD 16. The image signal of the two-dimensional CCD 16 is processed by the image processing circuit 23 to detect the position of the bright spot 33. The calculation / control circuit 17 calculates the axial position of the eye to be inspected from the detected position of the bright spot and the detected position of the left screen 30.

Here, the intersection point (measurement site) of the optical axes of the first alignment detection optical system, the second alignment detection optical system and the laser projection system is a reference point O, and the optical axis of the first alignment detection optical system. and second alignment detection optical system and the optical axis of the deflection of each x corneal reflection bright spot P, x', second alignment detection optical system of the first alignment detection optical system and contact angle of theta _2, the reference point O And z is the axial deviation of the corneal reflection bright spot P in the first alignment detection optical system, z
Is

[Equation 1] (See FIG. 3).

From the deviation of the apparatus with respect to the eye to be inspected thus obtained, the three-dimensional position coordinates of the current measurement site are specified and displayed on the screen 31. When the measurement site is determined, the laser light source 1 irradiates the eye with laser light. The laser light scattered at the measurement site is condensed by the imaging lens 8, passes through the dichroic mirror 9, and then forms an image on the aperture 10. The aperture 10 is for limiting the measurement area, and the scattered light is detected by the light receiver 11 behind it. Then, the degree of turbidity at the measurement site is measured by analyzing the detected scattered light intensity. The measured results are stored in the storage unit 18 together with input values such as the patient's ID number and measurement date, and the position coordinates of the measurement site when the trigger signal is generated. As the storage means, a storage medium such as a floppy may be used in addition to storing in a storage circuit in the device.

At the time of remeasurement, the coordinate value is called by inputting the patient's ID number or the like with the input means 19 (the coordinate value may be directly input), and the XYZ drive means 20 is operated based on the called coordinate value. And move to the alignment position automatically. Various well-known XYZ driving means can be used, but a three-dimensional moving mechanism known as a joystick mechanism of an ophthalmologic apparatus may be moved by a motor or the like (for detecting the position in each direction). (It becomes more accurate when set to) Also, after alignment, the servo mechanism of the device works to automatically fix the set position.
Although the first embodiment has been described with respect to the case where the first detection optical system coincides with the optical axis of the alignment light source, it does not necessarily have to coincide. As described above, the embodiment can be variously modified.

[0017]

Second Embodiment In the second embodiment, two alignment detection optical systems are arranged symmetrically with respect to the visual axis. The alignment projection optical system is on the visual axis as in the first embodiment. The laser scattered light detection optical system and the alignment detection optical system are separated. With respect to the laser projection optical system or the laser scattered light detection optical system, the angle between the laser projection optical system and the laser scattered light detection optical system is not changed, and the laser projection optical system and the laser scattered light detection optical system are arranged symmetrically with respect to the visual axis of the eye to be examined. Thus, when the pupil of the eye to be inspected is small, the problem that the measurement light beam is easily eclipsed is improved.

FIG. 4 shows an outline of the apparatus of the second embodiment. First
The alignment detection optical system includes an imaging lens 14b and a diaphragm 1.
5b and a two-dimensional CCD 16b. The second alignment detection optical system includes an imaging lens 14a, a diaphragm 15a, and a two-dimensional C
It consists of a CD 16a. The alignment observation system includes a half mirror 7, an image forming lens 8 and a light receiver 25. The laser scattered light detection optical system includes an imaging lens 26, a diaphragm 10, and a light receiver 11.
Consists of. The alignment projection optical system includes a collimating lens 24 and a point light source 6 that convert the alignment light into a parallel light flux. The laser projection optical system is the same as that in the first embodiment. The alignment observation optical system observes the anterior segment of the eye to be examined,
Coarse alignment is also performed, and the state of the laser light flux in the eye is also observed.

Next, the detection of the alignment deviation amount will be described with reference to FIG. The angle formed by the first alignment detection optical system and the second alignment detection optical system with the alignment projection optical system is α, and the intersection O of the respective detection optical systems
Therefore, when the corneal reflection bright point P is deviated by (Δ, θ),
Deflection amount of each detection optical system (Δ1x, Δ1y), (Δ2
(Δ, θ) is calculated from (x, Δ2y). (However, (Δ,
θ) is the projection of the three-dimensional deviation on the xz plane)

From FIG. 5, Δ1x = Δsin (π / 2−θ−α) = Δcos (θ + α) Δ2x = Δsin (π / 2 + θ−α) = Δcos (θ−α) From these, Δ and θ can be calculated. , Tan θ = ((Δ2x−Δ1x) / (Δ2x + Δ1x)) · cot α Δ = (Δ1x + Δ2x) / (2cos θcos α) If this is converted into the x and z direction components, Δx = Δcos θ = (Δ1x + Δ2x) / (2cos α) Δz = Δsin θ = (Δ2x−Δ1x) / (2sin α) In the y-axis direction, since the y deviation detected by each alignment detection optical system is Δy, Δy = Δ1y = Δ2y (Δx, Δy, Δz) can be obtained from the detection amounts of the first and second alignment detection optical systems. From the thus obtained three-dimensional displacement of the apparatus with respect to the eye to be inspected, the three-dimensional position coordinates of the current measurement site are detected and displayed on the monitor 22.

[0021]

According to the present invention, the alignment can be performed at any position of the patient's eye, and the reproducibility is improved over time.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an outline of an apparatus according to a first embodiment.

FIG. 2 is a diagram showing an example of a display screen of a monitor of the device.

FIG. 3 is an explanatory diagram for calculating a position of a measurement site.

FIG. 4 is an overall configuration diagram showing an outline of an apparatus according to a second embodiment.

FIG. 5 is an explanatory diagram for obtaining an alignment deviation amount.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 laser light source 4 eye to be inspected 5 crystalline lens 6 point light source 11 light receiver 12, 15, 15a, 15b diaphragm 13, 16, 16a, 16b two-dimensional CCD 14, 14a, 14b imaging lens

Claims (6)

[Claims] 1. An ophthalmologic apparatus for inspecting an eye to be inspected by an inspecting means by aligning a desired site in the eye, and an observation optical system for observing an anterior segment of the eye to be inspected, and a light beam for alignment to a cornea of the eye to be inspected. A projection optical system for projecting light onto the eye, a detection optical system for detecting corneal reflected light by the projection optical system from two directions, and a three-dimensional position for the eye to be inspected based on the detection result of the detection optical system. A position calculating means for obtaining, a signal generating means for generating a signal for performing an inspection of the eye to be inspected, and a holding means for storing and holding a three-dimensional position with respect to the eye to be inspected when the signal is generated by the signal generating means together with an inspection record. An ophthalmologic apparatus characterized by: 2. The ophthalmologic apparatus according to claim 1, wherein the projection optical system projects the light beam to the cornea of the eye to be examined via a member for reflecting the alignment light beam arranged in the observation optical system. 3. The observation optical system according to claim 1, comprising a two-dimensional image pickup device and a display for displaying an image picked up by the image pickup device, wherein the two-dimensional image pickup device is one of the detection elements of the detection optical system. An ophthalmic device that is also used as one. 4. The ophthalmologic apparatus according to claim 1, having a laser projecting optical system for projecting a laser beam onto an eye crystalline lens to be inspected, and a laser scattered light detecting optical system for detecting scattered light of the projected laser beam. An ophthalmologic apparatus characterized by the above. 5. The ophthalmologic apparatus according to claim 4, wherein the laser projection optical system and the laser scattered light detection optical system have optical axes that are symmetrical with respect to the optical axis of the observation optical system. 6. An ophthalmologic apparatus for aligning a desired site in an eye and inspecting an eye to be inspected by an inspecting means, an observation optical system for observing an anterior segment of an eye to be inspected, and a light beam for alignment to a cornea of an eye to be inspected. A projection optical system for projecting light onto the eye, a detection optical system for detecting corneal reflected light by the projection optical system from two directions, and a three-dimensional position for the eye to be inspected based on the detection result of the detection optical system. A position calculating means to be obtained, an inspection site designating means for designating coordinates of a site to be inspected, and a drive means for driving the inspection system of the eye to be examined with respect to the eye based on the inspection site designating means and the position computing means. An ophthalmologic apparatus characterized by having.