JPH0739519A - Ophthalmologic measuring apparatus - Google Patents

Abstract

PURPOSE:To measure the fluorescent intensity from the cornea of eye to be examined or tear therefrom with a fluorescent agent dropped easily and quantitatively under the various measuring conditions. CONSTITUTION:A mask 65 with an opening pattern of a specified size to determine the illuminating visual field arranged at a position conjugate with a measuring point P within the light projecting section 1 and a mask 40 with an opening pattern of a specified size to limit the measuring area arranged at a position conjugate with the front measuring point P of a photoelectric conversion device 42 in the light catching section 2 are changed at the time of measuring the tear or the local position or wide area of cornea, respectively, to those suitable for the respective measurements. The masks 65 and 40 are switched by inserting the masks in the respectively corresponding shapes into the illuminating light channel or detaching therefrom in an interlocking manner through the solenoid, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ophthalmic measuring apparatus, and more particularly to an ophthalmic measuring apparatus for measuring fluorescence of cornea or lacrimal fluid of an eye to be examined.

[0002]

2. Description of the Related Art Fluorescence measurement of corneal epithelium and lacrimal fluid instilled with a fluorescent agent (vital staining test) determines ophthalmic diseases such as dry eye (lacrimation) and abnormal corneal permeability (barrier function). Extremely important above. Conventionally, visual judgment using a slit lamp microscope has been frequently used, while a photographic measurement method has been reported as a quantitative method, but a method that can be easily applied clinically has not yet been completed.

In the conventional visual judgment, there is a problem that the judgment standard differs depending on the individual difference and the reliability of the data is lacking. Therefore, in order to solve this problem, in recent years, the illumination light is applied to the inside of the eye and the fluorescence applied in advance is applied. Ophthalmic measurement is performed by receiving fluorescence from the eye of the agent and quantitatively analyzing it. Such a technical idea is disclosed in, for example, Japanese Patent Laid-Open No. 58-183.
No. 135 and Japanese Examined Patent Publication No. 61-52694.

[0004]

By the way, when measuring the fluorescence intensity from the cornea and the lacrimal fluid, the setting conditions of the suitable measurement region are different depending on the measurement object, and the apparatus for performing the fluorescence measurement is as follows. It is preferable to be able to correspond to each set condition.

For example, when measuring the fluorescence intensity from the corneal epithelium or the tear fluid, the tear fluid accumulated in the lower eyelid is the object of measurement in the tear fluid measurement. Shape) is preferred.

On the other hand, in the local corneal measurement for identifying the location of inflammation of the cornea and mapping the degree of inflammation, it is preferable that the measurement region is as small as possible in consideration of resolution.

[0007] Further, in the corneal wide area measurement in which a wide range of the cornea is measured in order to quantify inflammation and the like of the entire cornea at one time, it is preferable that the measurement region is as large as possible in consideration of the integration effect.

As described above, there are various effective measurement methods depending on the measurement site and the measurement content. Therefore, it is difficult to measure the cornea and the lacrimal fluid with a single device by the conventionally known configuration. .

The object of the present invention is to solve the above problems and to quantitatively measure the fluorescence intensity from the cornea or lacrimal fluid of an eye to be inspected with a predetermined fluorescent agent under various measurement conditions with good operability. An object of the present invention is to provide an ophthalmologic measuring device that can be configured simply and inexpensively.

[0010]

In order to solve the above-mentioned problems, in the present invention, in an ophthalmologic measuring device for measuring the fluorescence of the cornea or tears of the eye to be inspected, the illumination light is of a predetermined magnitude. Means for condensing at a measurement point, a light-projecting portion provided with an exciter filter for selectively transmitting only a predetermined wavelength, and from the measurement point of the eye to be inspected with a predetermined fluorescent agent A photoelectric conversion element for receiving fluorescence and a light receiving unit having a barrier filter selectively transmitting only a predetermined wavelength different from the light projecting unit, and a position conjugate with a measurement point in the light projecting unit. A mask having an opening pattern of a predetermined size for determining the illumination field arranged in, and for limiting the measurement region arranged at a position conjugate with the measurement point in front of the photoelectric conversion element in the light receiving section. Predetermined size A mask having an opening pattern, respectively when tear measurements, at topical corneal measurements, and employs a configuration to switch to those suitable for each measurement at the time of corneal wide measurement.

[0011]

With the above configuration, in the ophthalmologic measuring device that receives the fluorescence intensity from the cornea and the lacrimal fluid of the eye to be inspected in which the predetermined fluorescent agent is instilled to perform the ophthalmic measurement, the lacrimal fluid measurement, the local corneal measurement, and Wide area measurement of each cornea is efficient and 1
Can be done with a single device.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the drawings.

<Arrangement of Apparatus> FIGS. 1 and 2 show a schematic arrangement of an ophthalmologic measuring apparatus according to the present invention. In FIG. 1, reference numeral 1 designates a projector for projecting illumination light. In the light section, the light source 2 for illuminating the slit lamp microscope is provided in the light projecting section 1.
0, an illumination light source 60 for fluorescence measurement, an optical system for projecting illumination light to the eye 26, a light receiving element 66 (for example, a photodiode) for monitoring the illumination light amount for fluorescence measurement, and the like are stored. The flip-up mirror 23 can switch between the slit lamp microscope and the fluorescence measurement. In this embodiment, the flip-up mirror 23 is deviated from the optical path when the slit lamp microscope is used. It doesn't matter if it is the other way around). First, the light source 2 when using a slit lamp microscope
The illumination light from 0 illuminates the subject's eye 26 via the lens 21, the slit 22, the lens 24, and the prism 25.

The amount of illumination light from the slit lamp microscope light source 20 can be arbitrarily adjusted by turning the dimming button 14 shown in FIG.

Next, at the time of fluorescence measurement, a flip-up mirror is mounted in the optical path, and the illumination light from the light source 60 is a lens 61, a half mirror 62, and an exciter filter 6.
3. After passing through the mask 65 via the mirror 64, the eye 26 to be inspected is further illuminated via the flip-up mirror 23, the lens 24, and the prism 25.

The mask 65 has an opening of a predetermined size that determines the illumination visual field during fluorescence measurement. Optimal opening patterns are provided for tear measurement, corneal local measurement, and wide corneal measurement. The mask you have is selected. The mask 65 is arranged at a position conjugate with a measurement point P described later. The detailed configuration of the mask 65 will be described later.

The exciter filter 63 is a visible blue transmission bandpass filter having a transmission peak near 490 nm, and can efficiently excite water-soluble sodium fluorescein used as a fluorescent agent (exciter filter). The light transmitted through 63 will be specifically referred to as excitation light). Further, a part of the illumination light for fluorescence measurement is branched by the half mirror 62 and is incident on the light receiving element 66 formed of a photodiode or the like. The signal from the light receiving element 66 is input to an automatic light amount adjusting mechanism including an automatic light adjusting circuit 48 connected to the arithmetic unit 45, and voltage control or phase control of the illumination light source 60 for fluorescence measurement is performed. The amount of illumination light is kept constant.

The light receiving section 2 is for observing the eye to be inspected 26 or for measuring fluorescence of the eye to be inspected 26. An optical system for observing the eye to be inspected 26 and an optical system for performing fluorescence measurement are housed therein. ing. The light from the subject's eye 26 illuminated by the illumination light is the objective lens 27 and the special aperture mirror 2
8, variable power unit 29, lens 30, prism 31, 3
2, observed by the examiner 35 through the field stop 33 and the eyepiece 34. The scaling unit 29 is for converting the observation magnification, if necessary, and is scaled by the scaling unit switching knob 13. This is a mechanism that a conventional slit lamp microscope has.

The special aperture mirror 28 does not interfere with the optical path of the observation system. That is, the special aperture mirror 2
In FIG. 8, an elliptical aperture corresponding to the effective apertures of the two variable power units 29 for both eyes is provided on the optical path of the variable power unit 29, and the special aperture mirror 28 is different from the objective lens 27. Since it is arranged between the magnification unit 29, it does not affect anything even if the magnification of the observation system is changed, and it has a structure that does not impair its function when used as a slit lamp microscope. ing.

The subject's eye 26 on which a predetermined fluorescent agent is applied
The fluorescent light emitted from is reflected by the special aperture mirror 28 via the objective lens 27, and via the relay mirrors 37 and 38, the shutter 39, the mask 40, and the barrier filter 41, a photomultiplier tube (hereinafter referred to as a photomultiplier tube) that functions as a photoelectric conversion element. The light is received by 42.

The barrier filter 41 has a transmission peak of 5
It is a visible green transmissive bandpass filter with a wavelength of 20 nm to 550 nm, and is for efficiently transmitting fluorescence from water-soluble sodium fluorescein used as a fluorescent agent and efficiently cutting off excitation light which is harmful light. .

The mask 40 limits the field of view in order to cut off the light from an unnecessary area incident on the photomultiplier 42, and the mask 40 and a predetermined point P (measurement point P: described later) in the eye to be inspected. It is arranged so as to be conjugate with respect to the optical system of the section 2. As the mask 40, a mask having an optimum opening pattern is selected for the tear measurement, the local cornea measurement, and the wide corneal measurement. Details of the configuration of the mask 40 will be described later.

The output from the Photomul 42 is input to the counter 43 connected to the arithmetic unit 45 via the amplifier 50, and the fluorescence intensity detected by the Photomul 42 is counted as the number of pulses per unit time.

The count value of the counter 43, that is, the number of times of sampling and the total number of pulses are stored in a predetermined memory cell set in the memory 44 for each unit time. The arithmetic unit 45 performs arithmetic processing based on the measurement data stored in the memory 44, and the fluorescence intensity is measured. At that time, the measurement point P is set to the corneal epithelium when measuring the cornea, and the measurement point P is set to the tear fluid accumulated in the lower eyelid when measuring the tear fluid (FIG. 9).

The shutter 39 is opened to protect the photomultiplier 42 only at the time of fluorescence measurement.
It is inserted into or removed from the optical system via an input device such as a joystick 8 having a push button switch 9 provided above.

Further, in this embodiment, as in the known slit lamp microscope, the fixation lamp 5 made of a light emitting diode is arranged at a position where the examinee can fix it. The fixation lamp 5 can be freely moved by the link mechanism 6 and can be adjusted to an optimum position for the subject.
The color of the fixation lamp is selected to be a color (for example, red) different from the excitation light (blue).

Further, the light projecting portion 1 and the light receiving portion 2 can be independently rotated and moved in the horizontal plane about the rotation axis 3, and further, the angle is 30 ° when measuring the cornea and 90 ° when measuring the lacrimal fluid. It is fixed at an angle, and when used as a slit lamp microscope, it is configured to release the lock mechanism such as the click mechanism and rotate freely to observe the cross section of the eyeball. Has been done.

The power supply box 12 is provided with an automatic light control circuit 48 for the illumination light source 60, an electric circuit such as a computing unit 45, a memory 44, a counter 43, and a power supply (not shown).

Next, the overall procedure of the alignment procedure between the apparatus and the eye to be inspected and the measurement procedure will be described. However, since it is well known when used as a slit lamp microscope, only the case of fluorescence measurement will be described here. To do.

First, the light projecting section 1 and the light receiving section 2 are set at a predetermined angle. Here, in the case of cornea measurement, the angle between the light projecting section 1 and the light receiving section 2 is set to 30 ° as shown in FIGS. In the case of tear measurement, the angle between the light projecting unit 1 and the light receiving unit 2 is set to 90 ° as shown in FIGS.

In any case, it is preferable that a lock mechanism such as a click mechanism is provided in the rotating mechanism of the light projecting portion 1 and the light receiving portion 2 so that the rotating mechanism can be fixed at the above angle. Thereby, the fluorescence measurement can be started quickly.

The subject's chin is placed on the chin base 4, the flip-up mirror 23 is mounted in the illumination optical path, the fluorescent light source 60 is then turned on, and the joystick 8 is operated to open the opening of the mask 65. The image is projected onto the measurement point P of the eye to be inspected 26 and the measurement point P is illuminated. The measurement point P is set to the corneal epithelium in the case of measuring the cornea and to the tear fluid accumulated in the lower eyelid in the case of measuring the tear fluid (FIG. 9).

In fluorescence measurement, tear measurement, corneal local measurement,
It is conceivable to perform wide area measurement of the cornea and the cornea, but at the time of each of these measurements, as described later, the masks 40 and 65
Are interlocked with each other to switch to the optimum opening pattern. This mask selection is possible by putting each mask into and out of the illumination optical path using a solenoid or the like.

Here, the setting in each case of the cornea measurement and the tear measurement will be described.

When measuring the cornea, the angle (measurement angle) between the light projecting portion 1 and the light receiving portion 2 is set to 30 ° in order to limit the measurement site to the corneal epithelium B and to avoid the influence of the iris and the crystalline lens. This is for easy observation. In FIG. 7, the measurement area is a portion shown as a focal diamond (effective measurement area), and only the fluorescence emitted from this area is received without being affected by the mask. If the measurement angle of 30 ° becomes large or small, it becomes difficult to observe, and the iris or the crystalline lens may easily affect the observation.

In the case of measuring tear fluid, the measurement angle is set to 90 ° in order to avoid the influence of the conjunctiva (the so-called white eye) and to facilitate focusing on the tear fluid. In this state (see FIG. 10), the effective measurement area is a portion where the excitation light, the focal diamond, and the tear fluid C (the portion where the fluorescent agent exists) accumulated in the lower eyelid overlap. If the measurement angle deviates from 90 °, the conjunctiva is more likely to affect the measurement and it becomes difficult to focus on the tear film surface.

After the alignment is achieved as described above, the push button switch 9 of the joystick 8 shown in FIG. 1 is pressed, whereby the shutter 39 is opened, and the fluorescence intensity from the subject's eye 26 in which the fluorescent agent is applied. Is measured, and after the shutter is opened for a certain period of time, the shutter 39 is automatically closed to complete the measurement.

The above operation is repeated several times as necessary,
The output device 46 outputs the respective measurement results and the totalization result such as the average value. In this case, the output device 46 is selected from a display and / or a printer.

11 and 12 show the output results of the cornea measurement and the tear measurement to the display or printer, respectively.

In FIG. 11, the output format in which the measured values are arranged along with the average value for each number of times is adopted. Further, in the case of the tear measurement shown in FIG. 12, the graph of the regression line of the logarithmic value of the measurement value and the measurement time and the correlation coefficient thereof are also output. This allows the tear volume to be calculated.

After the fluorescence measurement is completed, the light projecting section 1 and the light receiving section 2
The lock mechanism is released and the flip-up mirror 23 is removed from the illumination optical path so that it can be used as a slit lamp microscope.

<Structure and Switching of Masks 40 and 65> As described in the section of the problem, different measurement conditions need to be set in order to perform favorable fluorescence measurement of tear fluid or cornea.

Therefore, the mask 65 for the light projecting portion and the mask 40 for the light receiving portion (which are respectively arranged at the positions conjugate with the measuring point P) are used at the time of the lacrimal fluid measurement, the local corneal measurement, and the wide corneal measurement. It is possible to prepare an optimal shape and switch this for each measurement target.

FIGS. 13, 15 and 17 show examples of the shape of the mask 65 at the time of measuring tear fluid, at the time of local measurement of the cornea and at the time of measuring wide area of the cornea respectively, and FIGS. 14, 16 and 18 respectively show tears. The example of the shape of the mask 40 at the time of a liquid measurement, a local cornea measurement, and a wide corneal measurement is shown. Hereinafter, the shape of each mask during the measurement of tears, the local measurement of the cornea, and the wide area measurement of the cornea will be described.

When measuring tears, a mask 65 having an opening shape as shown in FIG. 13 and a mask 40 having an opening shape as shown in FIG. 14 are used. The mask 65 of the light projecting portion has a vertically long slit-shaped opening 6 corresponding to the vertical direction of the subject's eye.
It consists of 51. It is preferable that the width a be small to some extent. When the width a of the opening 651 becomes wider, the width of the excitation light in FIG. 10 becomes wider, and harmful light can be easily received, and focusing becomes difficult.

On the other hand, the mask 40 of the light receiving portion is formed as a horizontally long slit as shown in FIG. The lateral width corresponds to the size of the image of the eye to be examined. The opening shape is 40
It may be rectangular as shown by 1, or may be formed into a meniscus like as 402. The meniscus shape like the opening 402 corresponds to the shape of tears accumulated in the lower eyelid of the eye to be inspected, and the light receiving efficiency can be improved by adopting such a shape corresponding to the shape of tear fluid. .

At the time of local measurement of the cornea, a mask 65 having an opening shape as shown in FIG. 15 and a mask 40 having an opening shape as shown in FIG. 16 are used. In the local corneal measurement, both the masks 65 and 40 have pinhole-like shapes (652, 4
03) is adopted.

In the illustrated example, a circular pinhole is illustrated, but a rectangular shape may be used as long as it is a minute opening. This aperture size should be small, but if it is too small, a sufficient amount of light cannot be obtained, so it is set to a small value within the range in which the amount of light required for measurement can be secured. Size of mask 65 b
Is a local corneal measurement, so it is preferable to set the depth of the focal diamond from the corneal surface shown in FIG. 7 to match the corneal thickness, that is, about 0.5 mm.
For example, if the diameter of the eye to be inspected is about 0.1 mm according to the magnification, the depth from the corneal surface of the focal diamond shown in FIG. 7 can be adjusted to the thickness of the cornea, that is, about 0.5 mm.

The opening 403 of the mask 40 is formed on the cornea of the eye to be examined so as to have the same size and shape as the opening 652 of the mask 65 according to the magnification of the optical system.

When measuring the wide area of the cornea, a mask 65 having an opening shape as shown in FIG. 17 and a mask 40 having an opening shape as shown in FIG. 18 are used. As shown in FIG. 17, the opening 653 of the mask 65 is circular and as large as possible so that the iris does not cover the eye to be examined (for example, the diameter c = 2 to 3 m).
If m) is taken, the integration effect can be obtained over a wide area of the cornea.

On the other hand, the opening 404 of the mask 40 is shown in FIG.
As shown in FIG.
It is preferable that the small apertures (pinholes) are aligned with the apertures 653 of No. 5 in FIG. It is preferable that all the light in the illumination range by the opening 653 of the mask 65 can be received.
If the same diameter as 53 is adopted, the focal diamond of FIG. 7 in the light receiving system also becomes large, and deep measurement is performed in the depth direction, which makes it easier to receive harmful light. For example, the measurement range is
Since there are many focal diamonds corresponding to the size of each small opening, there is an advantage that the influence of harmful light can be reduced.

The masks 40 and 65 can be switched by using a solenoid or the like to move the respective masks into and out of the optical path, and a complicated mechanism is not required.

As described above, the masks 65 and 40 for the light projecting portion and the light receiving portion are switched to the optimum shape for each of the lacrimal fluid measurement, the corneal local measurement, and the wide corneal measurement, so that the masks 65 and 40 can be adjusted according to the object to be measured. Since suitable measurement conditions can be set, various fluorescence measurements can be performed with one device.

In the above, an example in which the device is configured as a slit lamp microscope capable of measuring fluorescence has been shown, but it goes without saying that the present invention can be applied to various ophthalmologic measuring devices for performing fluorescence measurement.

[0055]

As is apparent from the above, according to the present invention, a mask having an opening pattern of a predetermined size for determining an illumination visual field, which is arranged at a position conjugate with a measurement point in a light projecting portion, A mask having an opening pattern of a predetermined size for limiting the measurement region arranged at a position conjugate with the measurement point in front of the photoelectric conversion element in the light receiving part, respectively, when measuring lacrimal fluid, during corneal local measurement, Since it adopts a configuration that switches to an appropriate one for each measurement depending on the time and wide area measurement of the cornea, the fluorescence intensity from the cornea or lacrimal fluid of the eye to be inspected with a predetermined fluorescent agent can be easily operated under various measurement conditions. It is possible to provide an ophthalmologic measuring device that can be quantitatively measured and can be configured at a low cost.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of an ophthalmologic measuring apparatus adopting the present invention.

FIG. 2 is an explanatory view showing the internal structure of the apparatus of FIG. 1 from the side.

FIG. 3 is a side view of the special aperture mirror of FIG.

FIG. 4 is a top view of the special aperture mirror 28 of FIG.

5 is a perspective view of the special aperture mirror 28 of FIG. 2. FIG.

FIG. 6 is a top view of an optical system when measuring a cornea according to the present invention.

FIG. 7 is a more detailed top view of the optical system when measuring the cornea according to the present invention.

FIG. 8 is a top view of the optical system when measuring tears according to the present invention.

FIG. 9 is an explanatory diagram of a measurement region when measuring tear fluid according to the present invention.

FIG. 10 is a top view of a measurement region when measuring tears according to the present invention.

FIG. 11 is an explanatory diagram showing an output example when measuring a cornea according to the present invention.

FIG. 12 is an explanatory diagram showing an output example at the time of tear measurement according to the present invention.

FIG. 13 is an explanatory diagram showing a configuration of a mask 65 in an ophthalmologic measuring apparatus adopting the present invention.

FIG. 14 is an explanatory diagram showing a configuration of a mask 40 in an ophthalmologic measuring apparatus adopting the present invention.

FIG. 15 is an explanatory diagram showing a configuration of a mask 65 in an ophthalmologic measuring apparatus adopting the present invention.

FIG. 16 is an explanatory diagram showing a configuration of a mask 40 in the ophthalmologic measuring apparatus adopting the present invention.

FIG. 17 is an explanatory diagram showing a configuration of a mask 65 in an ophthalmologic measuring apparatus adopting the present invention.

FIG. 18 is an explanatory diagram showing a configuration of a mask 40 in an ophthalmologic measuring apparatus adopting the present invention.

[Explanation of symbols]

 1 Light Emitting Unit 2 Light Receiving Unit 8 Joystick 12 Power Box 14 Light Control Button 20 Light Source 21 Exciter Filter 22 Slit 23 Flying Mirror 26 Eye to be Inspected 27 Objective Lens 28 Special Aperture Mirror 29 Zoom Unit 33 Field Aperture 40 Mask 42 Photomar (Photoelectron Multiplier tube 45 Calculation device 46 Output device 48 Automatic light control circuit P Measuring point 61 Lens 62 Half mirror 63 Exciter filter 64 Mirror 65 Mask

Claims (2)

[Claims] 1. An ophthalmologic measuring device for measuring fluorescence of a cornea or a tear fluid of an eye to be inspected, a means for converging illumination light to a measurement point of the eye to be inspected with a predetermined magnitude, and selecting only a predetermined wavelength. A projection unit having an exciter filter for selectively transmitting light, a photoelectric conversion element for receiving fluorescence from the measurement point of the eye to be inspected with a predetermined fluorescent agent, and the projection unit different from each other A light-receiving unit having a barrier filter that selectively transmits only the wavelength of, and having an aperture pattern of a predetermined size that determines an illumination field arranged at a position conjugate with the measurement point in the light-projecting unit. And a mask having an opening pattern of a predetermined size for limiting a measurement region arranged at a position conjugate with the measurement point in front of the photoelectric conversion element in the light receiving unit, respectively when measuring tear fluid. , Corneal office During measurement, and ophthalmic measuring apparatus characterized by switching to those suitable for each measurement at the time of corneal wide measurement. 2. The ophthalmologic measuring apparatus according to claim 1, wherein the opening pattern of the mask used in the light receiving portion at the time of the wide area measurement of the cornea is configured as an aggregate of small openings.