JPS6266832A - Method and apparatus for measuring potential of cornea - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method and device for measuring retinal potential, and in particular to a method for effectively and safely detecting retinal action potential without bringing an electrode into direct contact with the cornea. The present invention relates to a method and device for measuring retinal potential.

(Prior Art) Human or animal eyes usually have (+) on the corneal side;
There is a resting potential indicating a (-) potential on the rear rod side, and it is known that this resting potential changes at the moment when the 'fA membrane is exposed to light and the moment when the light disappears. There is.

This phenomenon is widely used in inspections, research, etc., and for example, the recording of such potential fluctuations with time as the horizontal axis is the so-called ERG (Electroretinog).
ram: WIN electrogram) and kF! This captures the action potential of the membrane. ERG is the most widely used electrophysiological test for the retina or vision, and is characterized in that the potential fluctuations in the eyeball are objective responses, such as intermediate translucency. It is widely applied as an effective testing method for retinal function tests when the fundus cannot be seen through due to body opacity, and for diagnosing retinochoroidal diseases.

By the way, as an effective method for deriving the action potentials that are generated widely in the retina in response to light stimulation as mentioned above,
It is detected and measured as the potential difference between an electrode that is brought into direct or indirect contact with the corneal surface of the eyeball (an indifferent electrode) and an electrode that is brought into contact with the forehead, etc. and whose potential is set to zero (an indifferent electrode). method has been adopted.

Contact lens-type electrodes, loop-type electrodes, microfiber electrodes, etc. have been proposed as the electrodes for detecting the potential on the corneal surface, but conventionally, they have been proposed for ease of measurement and efficiency of potential detection. For safety and other reasons, contact lens-type electrodes are commonly used, and in particular, the inner surface of the sclerocorneal contact lens, in contact with the limbus, is made of conductive metals (gold, silver, platinum, etc.) that can withstand corrosion. etc.) embedded in a ring shape is preferably used. In addition, in recent years, various contact lens-type electrodes have been proposed, such as those with electrodes embedded in corneal contact lenses and those with soft lenses (
Utility Model Publication No. 49-7517, Utility Model Publication No. 11678-1978,
(See Japanese Unexamined Patent Publication No. 132950/1983, etc.).

(Problems) However, since all of the conventional electrodes mentioned above are of the solid cornea contact type, they have a number of unavoidable problems.

In other words, when wearing such a related electrode, it is very uncomfortable and causes discomfort for the subject, and it is not desirable for corneal surgeons to apply foreign body stimulation to the cornea. Therefore, it was not possible to perform such measurements.

Additionally, if there is a large difference in the radius of curvature between the contact lens and the cornea, air bubbles may form between the two when the electrode is worn, or the tear fluid intervening between the two may become intermittent, causing the electrode and the cornea to become disconnected. Non-contact parts are likely to occur, which may generate noise in the detection current and reduce measurement accuracy. In order to suppress such a reduction in measurement accuracy, the sensor has various radii of curvature. It was necessary to have contact electrodes on hand at all times.

In addition, since the contact lenses and the like constituting the electrodes are brought into direct contact with the cornea, such mechanical stimulation tends to cause corneal damage. Even when eye drops are repeatedly administered, corneal damage is likely to occur due to the side effects of the anesthetic.

Furthermore, it is somewhat difficult to see the optotype, and the black edge of the electrode or contact lens overlaps the pupil area, which tends to obstruct the stimulation light from entering the pupil. It was.

In other words, a related electrode for detecting retinal action potentials must be able to minimize stimulation of the cornea (it must be able to prevent drying of the cornea during measurement, it must be able to suppress blinking, and at the same time It is necessary that the field of view is not obstructed by such an electrode, and that it is also hygienic and economical, but no electrode has been found that meets these conditions.

(Solution Means) The present invention has been made against this background, and its gist is that a cylindrical container containing a predetermined electrolyte solution is used when measuring retinal potential. is used to emit light from a light source provided at the bottom of the cylindrical container to provide a predetermined optical stimulation to the retina through the cornea that has been brought into contact with the electrolyte solution, while electrodes immersed in the electrolyte solution The reason is that action potentials in the retina can be detected by Further, when carrying out the present invention, (a) a cylinder containing a predetermined electrolyte solution and whose upper opening is a bowl-shaped or flared-shaped eyelid opening part for contacting the cornea with the electrolyte solution; (b) an electrode placed in a region close to the cornea that is immersed in the electrolyte solution contained in the cylindrical container and brought into contact with the electrolyte solution; and (C) a cylindrical container. Preferably, a device is used that includes a light source that is placed below the cornea and provides a predetermined optical stimulus to the retina through the cornea that is brought into contact with an electrolyte solution.

(Action/Effect) That is, according to the present invention, the electrode of interest for detecting retinal action potentials is placed in a predetermined container without being brought into direct contact with the eye to be examined, and is placed inside the container. It is connected to the cornea of the eye to be examined via an electrolyte solution contained in the eye. Then, the action potential of the y4 membrane in response to light emitted from a predetermined light source provided at the bottom of the container is detected as a potential difference between the concerned electrode and an indifferent electrode brought into contact with the forehead or the like and brought to zero potential. That's what happens.

Therefore, when detecting such potential, the electrolyte solution is simply brought into contact with the cornea of the eye to be examined, so that the examinee does not feel any discomfort or discomfort. Even in people who have undergone corneal surgery, it is possible to perform measurements satisfactorily without causing foreign body stimulation.

In addition, since the space between the indifferent electrode and the cornea is uniformly filled with the electrolyte solution, there are no air bubbles between the two, and the noise caused by this can be effectively suppressed. Therefore, measurement accuracy can be significantly improved. Furthermore, since the electrolytic solution makes good contact with the cornea of any curvature, it becomes possible to apply one type of device to measurements of all subjects.

Furthermore, since solid objects such as indifferent electrodes are not brought into contact with the cornea, corneal damage is not induced even if such measurements are repeated, and there is no need for eye drops. No corneal damage may occur.

In addition, since the light source is arranged at the bottom of the container in which the electrolytic electrode and electrolyte solution are housed, the distance, position, etc. of the light source can be set extremely easily and well.

That is, according to the present invention, when measuring retinal action potentials, there is almost no stimulation to the cornea, drying of the cornea can be effectively prevented during the measurement, and the eyelid opening formed at the upper part of the container can be prevented. This means that blinking can also be suppressed well depending on the area. Furthermore, by exchanging the electrolyte solution, it is possible to use the method and apparatus any number of times, making it possible to provide an extremely hygienic and economical method and apparatus for measuring retinal action potentials.

(Examples) Hereinafter, in order to clarify the present invention more specifically, some examples according to the present invention will be described in detail based on the drawings.

First, FIG. 1 shows a cross-sectional view of a retinal potential measuring device 10 as an embodiment according to the present invention. In this figure, reference numeral 12 denotes a container having a substantially cylindrical shape, and a transparent plate 14 is provided inside the container 12 as a partition wall that partitions the inside of the container 12 into two spaces in the length direction. and,
In the upper space of the container 12 partitioned by the transparent plate 14, a ring-shaped electrode 18 is immersed in the electrolyte solution 16 contained in the space, and in the lower space, a strobe discharge tube is installed. 20 and a reflecting mirror 22 are provided.

More specifically, the container 12 is made of Pyrex glass,
It is a light-shielding container made of an electrically insulating material such as acrylic resin, and has a stepped structure consisting of a small diameter part 24, a large diameter part 26, and a bowl-shaped eyelid opening part 28 located at the upper end of the small diameter part 24. It has an approximately cylindrical shape. Then, the container 12
is opened at the upper part in the eyelid opening part 28, while the other end is sealed by a bottom plate 30 at the end of the large diameter part 26.

The transparent plate 14 is made of a material with high light transmittance such as glass, and is a disc-shaped member having the same planar shape as the hollow cross section of the small diameter portion 24 of the container 12. As a result, the internal space of the container 12 is fluid-tightly partitioned at the portion of the small diameter portion 24 on the side of the large diameter portion 26, and is divided into two upper and lower spaces.

An electrolyte solution 16 such as physiological saline, potassium chloride solution or Ringer's solution is stored in the internal space of the container 12 on the side of the eyelid opening 28 up to approximately the height of the center of the eyelid opening 28. At the same time, a ring-shaped electrode 18 as a related electrode is provided on the inner wall surface of the eyelid opening part 28 in a state of being immersed in the electrolyte solution 16. Note that the electrode 18 needs to be a neutral substance without photoelectric effect and polarization in order to avoid electromechanical reactions. Therefore, it is preferable to use a conductor made of gold, platinum, or the like, or whose surface is covered with such a material by plating or the like. Further, the contact surface of the electrode 18 with respect to the container 12 is processed into a shape corresponding to the inner surface of the eyelid opening part 28 that is brought into contact, and conducts the electric signal detected by the electrode to a predetermined device. The lead wire 32 for the eyelid opening part 28
It is connected through the wall of the

On the other hand, a strobe discharge tube 20 held by a support plate 34 is disposed in the inner space of the container 12 on the side of the large diameter portion 26, located at the center of the lower part thereof. Further, between the support plate 34 and the light plate 14, a cylindrical reflecting mirror 22 having a truncated conical shape and having a mirror-finished inner surface is disposed so as to cover the strobe discharge tube 20. ing.

In order to obtain ERG, for example, using the electroretinogram measuring device 10 having the structure described above, first, as shown in FIG. A ground electrode 58 is connected to the earlobe or the like in order to bring the probe into contact with the subject's forehead or the like, and to set the potential of the indifferent electrode 36 to zero. Next, the cornea of the subject is immersed in the electrolyte solution 1 contained in the electroretinogram measuring device 10.
The electroretinogram measuring device 10 is set so that it can be brought into contact with the retinogram 6. At this time, as shown in FIG. 1, the subject's upper eyelid 38 and lower eyelid 40 are
Since the eyelids are opened by the eyelid opening part 28 of No. 2, they are not brought into contact with the electrolyte solution 16, and therefore only the eyeball 42 (cornea) of the subject is brought into good contact.

After dark adaptation or light adaptation for a predetermined period of time in order to stabilize the resting potential of the eyeball 42, the retina measuring device 1
A strobe discharge tube 20 placed at the bottom of the camera emits light to provide light stimulation to the retina.

The action potential generated in the retina by such an operation is detected as a potential difference between the potential on the corneal surface of the eyeball 42 and the indifferent electrode 36. In this embodiment, the potential on the corneal surface is Electrode 1 via electrolyte solution 16
8 is made conductive. The electrical signal from the cornea is then supplied to a known ERG main body 44 to remove noise and the like, and the potential fluctuations are electrically amplified, passed through a predetermined arithmetic circuit, etc. The electroretinogram is obtained by being recorded or displayed as a function of time. Note that FIG. 2 is a diagram illustrating an example of connections when this embodiment is applied as a device for measuring retinal action potentials for obtaining ERG, and in the figure, 46 is a preamplifier unit; 48 is a main amplifier section, 50 is a filter, 52 is an arithmetic circuit and control section,
54 is a recording section, and 56 is a strobe power source.

In the retinal potential measuring device 10 having the structure described in detail above, only the electrolyte solution 16 is brought into contact with the cornea during such measurements, so it is difficult for the subject to Such measurements can be performed satisfactorily without causing any discomfort or discomfort, and even in those who have undergone corneal surgery, foreign body irritation to the cornea can be avoided. Furthermore, such measurements do not induce corneal damage, and there is no need for eye drop anesthesia, so corneal damage cannot occur due to such anesthetics.

Further, an electrolyte solution 16 is provided between the electrode 18 and the eyeball 42.
Because of the interposition of the eyelid opening 28, corneal dryness can be effectively prevented, and air bubbles are not generated in the gap, and since blinking can be well prevented by the eyelid opening part 28, noise etc. Therefore, it is possible to obtain a good corneal surface potential without any damage.

Furthermore, in this embodiment, since the strobe discharge tube 20 as a light source is fixedly built into the lower space of the container I2, it is necessary to set the distance and position of the light source during such measurements. There is no need to do this. Furthermore, since the container 12 is a light-shielding container and its opening is sealed by the subject's eyelids 38, 40, etc., it is possible to completely block external light from entering the inside of the container 12. Become. Therefore, it is possible to perform measurements well even in a relatively bright place, and the operability can be greatly improved.

In addition, the retinal potential measuring device 10 of this embodiment has a simple structure, and the measurement accuracy is not influenced by the radius of curvature of the cornea, unlike conventional contact lens type electrodes, and can be used with one type of device. It can be applied to all subjects, and electrolysis! By replacing the solution 16, repeated use is possible in an extremely hygienic manner.

In other words, according to this embodiment, it was possible to economically provide an extremely hygienic retinal potential measuring device that has good measurement accuracy, operability, and safety.

Next, another embodiment according to the present invention will be described below.

FIG. 3 shows a cross-sectional view of another embodiment of an electroretinogram measuring device IO constructed according to the present invention.

In this figure, a container 60 is composed of an eyelid opening part 62, a small diameter part 64, and a large diameter part 66, and has the same outer shape as the container 12 in the above embodiment, which has a substantially cylindrical shape. A second convex lens 6 is located inside the small diameter portion 64 and serves as a partition wall that fluid-tightly partitions the inside of the container 60 into two spaces in the length direction.
8 are arranged in the direction perpendicular to the axis of the container 60.

In this upper space, an electrolyte solution 70 is stored up to approximately the height of the middle eyelid part 62, and on the inner wall surface of the eyelid part 62, a ring-shaped electrode is arranged as a related electrode. 72 are provided.

On the other hand, in the lower space, an annular flange 74 that protrudes into the inside of the small diameter portion 64 is provided at the boundary surface of the small diameter portion 64 with respect to the large diameter portion 66. A convex lens 76 is supported. Further, the inner space of the large diameter portion 66 has an end portion that is connected to the bottom plate 7.
A strobe discharge tube 82, which is sealed by a support plate 80 and held by a support plate 80, is placed at the center of the lower part of the space. Further, a cylindrical reflecting mirror 84 having a truncated conical shape and having a mirror-finished inner surface is disposed between the support plate 80 and the flange 74.

With such a structure, the strobe discharge tube 8
Since the stimulation light emitted from the eye 2 is focused by the first convex lens 76 and the second convex lens 68, the eye 42 to be examined can be more effectively irradiated with the stimulation light. That is, in the retinal potential measurement device of this embodiment, it is possible to focus such stimulating light on the M4 membrane of the eye to be examined 42, and furthermore, it is possible to focus the stimulating light on the M4 membrane of the eye to be examined 4
By focusing on the crystalline lens 2, the stimulating light is diverged by the crystalline lens and is evenly distributed and irradiated over a wide area of the retina.
Not only can the cone system and rod system of RG be recorded separately, but also the amplitude and peak tide time can be accurately analyzed.

In addition, in order to irradiate the stimulating light over a wide 9 area of the retina of the subject's eye as described above, the electrolyte solution 16 (70) in the above embodiment may be made cloudy, or the strobe discharge tube 20 (82) may be made cloudy. ) and the subject's eye 42, such as providing a diffusion filter.

The retinal potential measurement method and device according to the present invention have been described in detail above based on a few examples, but these are literal examples, and the present invention is not limited to these specific examples. It is not to be interpreted.

For example, in the embodiment described above, the container 12 (60) is a light-shielding container made of an insulating material, but it may have a structure in which the end of the eyelid opening part 28 (62) is covered with an insulating material such as rubber. By doing so, it is possible to insulate the related electrode 18 (72) from the subject, and furthermore, the container does not necessarily have to have a light shielding property.

Furthermore, although the electrode 18 (72) was ring-shaped, the electrolyte solution 18 (72) can be
6 (70) and can be arranged in a dot shape on the inner circumferential surface of the eyelid opening part 28 (62). It is also possible to provide it in the electrolyte solution 16 (70) without having to do so.

Furthermore, the eyelid opening part 28 (62) in the above embodiment is not limited to the bowl-shaped shape as illustrated, but the eyelid opening part 28 (62)
．． Various shapes that can maintain 40 in an open position may be employed as appropriate. Further, by forming the large diameter portion 26 (66) at the lower part of the container 12 (60), the stability of the device 10 is improved, and the electrolyte solution 16 (70) accommodated in the container 12 (60) is However, such a large diameter portion 26 (6
6) is not necessarily required, and such a container 12 (60)
The shape of is not limited.

Further, the light source is not limited to the strobe discharge tube 20 (82) as in the above embodiment, but it is also possible to use a set of electromagnetic shutters for stimulating light, and a polarizing plate is used to adjust the luminous intensity. etc. may be adopted as appropriate. Also,
The reflector m22 (84) is for effectively irradiating the retina of the subject with the stimulating light from the light emitting source, but the reflector 22 (84) is not necessarily necessary.

Furthermore, in the above embodiments, the present invention is
Although an example of use as a device for measuring the action potential of the M4 membrane to obtain RG has been shown, the present invention can also be applied to other pattern ER.
It can also be used satisfactorily in measurements of G and the like.

Although others are not listed, it goes without saying that the present invention can be implemented with various modifications and improvements without departing from the spirit thereof.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a retinal potential measuring device as an embodiment of the present invention, and FIG.
It is an explanatory diagram showing an example of the connection for obtaining RG. Third
The figure is a sectional view of a retinal potential measuring device as another embodiment of the present invention. 10: Retinal potential measurement device 12 (60): Container 16 (70): Electrolyte solution 18 (72): Electrode 20 (82): Strobe discharge tube 28 (62); Open eyelid area 36: Non-sensor electric scraper applicant
Rodo Kuchii Toyo Contact Lenses Co., Ltd. Figure 1 Figure 3

Claims (2)

[Claims] (1) Using a cylindrical container containing a predetermined electrolyte solution,
A light source provided at the bottom of the cylindrical container is made to emit light to provide a predetermined optical stimulus to the retina through the cornea brought into contact with the electrolyte solution, while an electrode immersed in the electrolyte solution stimulates the retina. A method for measuring retinal potential, characterized by detecting action potentials. (2) A cylindrical container that contains a predetermined electrolyte solution and whose upper opening is a bowl-shaped or flared eyelid part for contacting the cornea with the electrolyte solution; An electrode is placed near the cornea that is immersed in the electrolyte solution and brought into contact with the electrolyte solution; A retinal potential measuring device comprising: a light source for applying a predetermined optical stimulus.