JP2004329872A - Ophthalmologic examination apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To examine an ophthalmologic disease at a health check level on the basis of measurement data by detecting a cross-sectional form of an anterior ocular part of an eye to be examined as quantitative measurement data. <P>SOLUTION: This ophthalmologic examination apparatus for examining the ophthalmologic disease of the eye to be examined by detecting the cross-sectional form of the anterior ocular part of the eye to be examined includes an optical slit light projection system 34 for projecting slit light from a pupil area in the anterior ocular part of the eye to be examined to the periphery of the iris while moving the slit light for scanning, optical photographing systems 36, 40 for capturing a cross-sectional image of the anterior ocular part resulting from the light projected by the optical slit light projection system 34, and a computer part 55 for analyzing the cross-sectional image captured by the optical photographing systems to analyze the form of the anterior ocular part of the eye to be examined. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ophthalmic examination apparatus used for examination of an ophthalmologic disease such as glaucoma.

  Glaucoma is a disease in which the optic nerve is affected mainly due to an increase in intraocular pressure, resulting in visual field abnormalities and reduced visual acuity, and is a leading cause of blindness in ophthalmology. According to epidemiological studies, the estimated number of glaucoma patients in Japan is estimated to be 3 to 4 million. However, in most cases, glaucoma is diagnosed and treated by an ophthalmologist only after it has developed.Although it may happen that a patient with glaucoma may be discovered during ophthalmologic treatment, glaucoma may be detected by screening. At present, it is not performed to test persons at risk of developing in advance.

FIG. 1 shows a sectional structure of the eye. 10 is a cornea which is a transparent film in front of the eyeball, 12 is located in front of the crystalline lens, and has an iris whose main function is to adjust the amount of input light, 14 is a crystalline lens, 16 is a jelly-like transparent material. It is a vitreous body composed of various tissues. The lens 14 is supported by being suspended from the ciliary body 17 via the chin zonules.
The area surrounded by the cornea 10, the lens 14, and the iris 12 is called the anterior chamber 18, and the part surrounded by the iris and the vitreous is called the posterior chamber. The anterior chamber 18 and the posterior chamber 20 are filled with clear aqueous humor. Aqueous humor carries oxygen and nutrients to each tissue in the eye and transports waste products of each tissue in the eye to the outside of the eye. The aqueous humor is formed by the ciliary body 17, and is formed from the back chamber 20 to the anterior chamber 18. After that, the blood is discharged into the vein from the corner portion (portion A in the figure: a corner angle) sandwiched between the cornea 10 and the iris 12.

  Intraocular pressure indicates the pressure in the eyeball, and is determined by the balance between production and drainage of aqueous humor. That is, if the drainage capacity of aqueous humor decreases or the production capacity increases, the intraocular pressure increases. Conversely, if the drainage capacity increases or the production capacity decreases, the intraocular pressure decreases. Glaucoma most often occurs not because of an increase in the amount of aqueous humor that raises intraocular pressure, but because the amount of aqueous humor that is excreted outside the eye is reduced, thereby increasing intraocular pressure. . Since the production amount of aqueous humor is almost constant in the ciliary body regardless of the amount discharged to the outside of the eye, if the amount of aqueous humor discharged from the corner is suppressed, the intraocular pressure increases.

  The reason that the amount of aqueous humor discharged to the outside of the eye is reduced and the intraocular pressure is increased as described above is due to the aqueous humor in the mesh-like tissue and trabecular meshwork formed at the corner where the aqueous humor is discharged. When the permeability decreases and the aqueous humor becomes difficult to drain (open-angle glaucoma), and when the corner itself is originally narrow and there is a pressure difference between the anterior chamber 18 and the posterior chamber 20 for some reason, There is a case where the iris 12 is pushed from the back side toward the cornea 10 and the aqueous humor is not discharged because the root of the iris 12 blocks the corner (closed-angle glaucoma).

In open-angle glaucoma, the intraocular pressure rises slowly and the symptoms progress slowly, whereas in closed-angle glaucoma, the intraocular pressure rises rapidly by closing the outlet of aqueous humor, and the symptoms progress rapidly. There is a difference that blindness may occur within a few days. Both open-angle glaucoma and pre-seizure closed-angle glaucoma have no subjective symptoms, and in particular, closed-angle glaucoma has a tendency to rapidly progress when it develops. Pre-diagnosis is extremely important.
Of these open-angle glaucoma and closed-angle glaucoma, open-angle glaucoma is difficult to diagnose from corner findings because the shape of the corner is very similar to that of a healthy person. Investigate the angle and depth of the anterior chamber, and if the interval is narrow, treat it as a possibility of developing closed angle glaucoma and prevent it from occurring by treating it. It is possible.

  However, diagnosing angle-closure glaucoma in ophthalmic practice is not always easy. When diagnosing glaucoma or not, it is necessary to examine the distance between the cornea and the iris, especially the angle between the corners. Because it changes, it is difficult even for a specialist to determine whether there is a risk of developing the disease simply because the interval is short or wide. In addition, in order to find the distance between the cornea and the iris, a test lens (corner mirror) is applied to the cornea and the shape of the anterior chamber is visually checked. It is not practical to perform such specialized diagnostic tests.

In addition, since the method of testing using a test lens involves applying the test lens directly to the cornea, there is a problem that the cornea may be damaged by the lens or bacteria may be transmitted from the lens. There is a problem that this is an inspection method that imposes a burden on the user. For this reason, the method of inspecting using an inspection lens is actually performed by an ophthalmologist when there is a possibility of glaucoma during ophthalmic treatment.
In addition, there is also a method of inspecting the interval between the cornea and the iris using a slit light (slit lamp) without using an inspection lens, but this method simply visually recognizes the interval between the cornea and the iris. It only qualitatively evaluates the width of the interval, and the accuracy is much lower than the method of diagnosing using an inspection lens. The interval at the base (corner) of the iris is clearly defined. There is a problem that it is difficult to see and accurate diagnosis is difficult.

  Therefore, the present invention has been made to solve these problems, and an object of the present invention is to provide a closed angle glaucoma or an anterior chamber without an operation that requires a specialist to use a lens for examination. It is possible to test for ophthalmologic diseases in the part, which can be performed without imposing a burden on the subject, and can be used even by non-specialists, at the screening level for ophthalmic diseases such as glaucoma An object of the present invention is to provide an ophthalmic examination apparatus that can be used.

In order to solve the above problems, the present invention has the following configuration.
That is, an ophthalmic examination apparatus for examining an ophthalmologic disease of an eye to be inspected by detecting a cross-sectional shape of an anterior eye of the eye to be inspected. A slit light projection optical system for projecting while moving so as to scan the slit light, a photographing optical system for photographing a cross-sectional image of the anterior segment obtained by the projection light projected by the slit light projection optical system, A computer for analyzing the shape of the anterior segment of the eye by analyzing the cross-sectional image photographed by the photographing optical system.
By projecting the slit light onto the eye to be inspected by the slit light projection optical system, a cross-sectional image of the cornea, the iris and the like of the anterior segment of the eye to be inspected can be photographed by the photographing optical system by the photographing optical system. Normally, a cross-sectional image is captured by moving the slit light from the center of the pupil toward the periphery of the iris so as to scan. A method of recording multiple cross-sectional images while projecting slit light toward the subject's eye, a method of intermittently projecting slit light to record cross-sectional images, a method of recording and analyzing cross-sectional images as continuous images, etc. are possible. It is.

Since the slit light projection optical system is provided so as to project slit light obliquely with respect to the visual axis of the eye to be inspected, it is possible to suitably measure the shape of the anterior segment.
Further, it is effective that the slit light projection optical system is provided so that the projection position of the slit light can be set at a left position and a right position toward the subject according to the right eye or the left eye. It is.

The slit light projection optical system is provided to project slit light from an oblique direction having a fixed projection angle with respect to the visual axis of the eye to be inspected, and emits the slit light from the pupil of the eye to the periphery of the iris. A moving mechanism for moving the slit light projecting optical system together with the photographing optical system in the moving direction is provided.
By moving the slit light projecting optical system and the photographing optical system in synchronization by the moving mechanism, the shape of the anterior ocular segment can be obtained as a cross-sectional image by the slit light, and the projection angle of the slit light is fixed. Thus, the shape of the anterior segment such as the anterior chamber depth can be accurately grasped.
The imaging optical system includes a microscope for enlarging and visually recognizing a cross-sectional image of the anterior segment of the subject's eye, and a CCD camera for capturing the cross-sectional image.
Further, by providing a fixation lamp for aligning the eye to be inspected with the optical system of the inspection apparatus, and a fine movement alignment mechanism for finely adjusting the left and right position and the height position of the optical system by operating the joystick. , Accurate inspection becomes possible.

  Further, the computer unit captures and stores a cross-sectional image of the anterior eye at predetermined intervals when moving the slit light to scan from the pupil region to the periphery of the iris; Analyzing means for analyzing the shape of the anterior segment by image-analyzing each cross-sectional image recorded by the computer, and display means for displaying a result of analysis by the analyzing means. The shape of the anterior segment of the eye to be inspected can be quantitatively detected by analyzing the image data stored by the image storage unit by the analyzing unit, thereby accurately inspecting the shape of the anterior segment of the eye to be inspected. This makes it possible to make a highly reliable diagnosis of the possibility of the onset of an ophthalmic disease and the like.

  The ophthalmic examination apparatus according to the present invention can detect the cross-sectional shape of the anterior segment of the subject's eye as quantitative measurement data, thereby enabling the subject to develop an ophthalmologic disease, for example, closed-angle glaucoma. It is possible to carry out an accurate inspection on the properties and the like. In addition, since there is no need to use an inspection lens when measuring, it can be handled even by non-specialists, and highly reliable diagnosis can be made by examination at the examination level, and ophthalmic diseases can be diagnosed in advance. It has a remarkable effect that it can be suitably used as a detecting device.

Summary of the Invention

The inspection method using the ophthalmic inspection apparatus according to the present invention, the slit light is projected on the eye of the subject, the cross-sectional image of the cornea and the iris of the eye to be inspected by photographing the cross-sectional shape of the anterior segment, the inspection The measurement is performed remotely without using a lens or the like, and the symptoms are diagnosed based on the measurement result.
As mentioned above, the possibility of onset angle glaucoma can be determined by observing the distance between the cornea and the iris (anterior chamber depth) in the anterior chamber and measuring the interval. It is possible to diagnose whether there is.

In FIG. 1, the interval D indicates the anterior chamber depth. The anterior chamber depth D is wider at the center of the cornea 10 and becomes narrower as it approaches the periphery of the iris 12. Therefore, if the shape of the anterior chamber depth D can be measured for the subject's eye, the symptoms can be objectively grasped based on the measurement result.
FIG. 2 is a graph qualitatively representing the anterior chamber depth D with the horizontal axis representing the distance from the center of the pupil to the periphery of the iris and the vertical axis representing the anterior chamber depth D. As shown in the figure, the cornea 10 and the iris 12 are wide open on the center side of the pupil, but the depth of the anterior chamber becomes narrower as approaching the periphery of the iris 12. In other words, the graph of the anterior chamber depth is a downward-sloping graph.

The measured value of the anterior chamber depth D varies depending on the subject from the pupil to the periphery of the iris, and the depth of the anterior chamber depends on the subject when the depth is relatively deep (wide) and shallow (narrow). There are individual differences like there is. The test method according to the present invention, by accumulating the data of healthy subjects and affected individuals about the anterior chamber depth, by statistically comparing these data and measured values, for example, there is a possibility of obstruction angle glaucoma It is to determine whether or not there is. It is relatively easy to compare these data to determine a healthy person and a person who is likely to develop the disease, and it is possible to easily make a diagnosis at a screening level.
The inspection method according to the present invention can measure the anterior chamber depth as quantitative data, so that a much more objective diagnosis can be performed by computer processing or the like than the inspection method based on visual observation or the like. As a result, it is possible to make a diagnosis even without being a specialist, and the diagnosis can be effectively used as a diagnosis method at the examination level.

  When it is diagnosed that there is a possibility of obstruction angle glaucoma by this examination method, a more accurate judgment can be obtained by receiving a diagnosis by a specialist, and an appropriate treatment can be taken. If there is a possibility of developing closed-angle glaucoma, the onset of glaucoma can be avoided in advance by performing a treatment for opening a through hole using a laser in the periphery of the iris (laser iridotomy). This laser iridotomy is a treatment for equalizing the pressure of the aqueous humor in the anterior chamber 18 and the posterior chamber 20 by opening a communication hole communicating the anterior chamber 18 and the posterior chamber 20 with the iris 12. The onset of closed-angle glaucoma can be completely prevented. By performing such a treatment, it is possible to prevent the onset of closed-angle glaucoma thereafter.

Thus, if the method of the present invention can detect, for example, the symptoms of closed-angle glaucoma, the onset of closed-angle glaucoma can be prevented beforehand, which is extremely effective as prevention of ophthalmologic diseases.
As mentioned above, it is estimated that there are about 3 to 4 million potential glaucoma patients in Japan alone. If glaucoma can be detected beforehand at the screening level for these potential patients, it is extremely effective as prevention of ophthalmologic diseases.

Hereinafter, specific examples of an ophthalmic examination apparatus according to the present invention and an examination method using the examination apparatus will be described in detail with reference to the drawings.
FIG. 3 is an explanatory diagram showing the configuration of an embodiment of the ophthalmic examination apparatus according to the present invention. The ophthalmic examination apparatus according to the present embodiment projects slit light onto the eye of the subject, and moves the slit light from the center side of the pupil toward the peripheral portion of the iris while cross-sectioning the cornea and iris at predetermined intervals. The distance between the cornea and the iris can be measured by capturing an image and analyzing the captured image.

In FIG. 3, reference numeral 30 denotes a support table, and reference numeral 32 denotes a chin rest attached to a side edge of the support table 30 facing the subject. The subject puts his chin on the chin receiving portion 32a of the chin rest 32 and undergoes an examination.
Reference numeral 34 denotes a slit lamp as a slit light projection optical system for projecting slit light to the eye of the subject. The slit lamp 34 has a built-in light source at the top, and is configured such that slit light is projected toward the subject's eye by the mirror 34a. The slit light is adjustable in slit width and slit length.

  In the ophthalmologic examination apparatus of the present embodiment, the slit light projection optical system is set so that slit light is projected from an oblique direction to the eye to be examined. FIG. 1 shows a state in which slit light is projected obliquely to the eye to be examined. Projecting the slit light from the oblique direction to the subject's eye means that the subject projects the slit light from a direction inclined at a predetermined angle with respect to the normal viewing direction (the visual axis) in which the subject faces his / her front. . The slit lamp is operated so as to move toward the periphery of the iris from the center of the pupil while projecting slit light to the eye to be examined.At this time, the slit light is inclined at a predetermined angle with respect to the visual axis. Move while standing.

In the ophthalmic examination apparatus according to the present embodiment, the slit light is set to project toward the subject's eye from a position inclined 60 ° rightward or leftward from the normal viewing direction of the subject's eye. The reason why the slit light is projected from the oblique direction to the subject's eye is to enable the subject to measure the anterior chamber depth without dazzling.
In addition, the slit light can be projected to the subject from the right or left direction because the projection direction of the slit light must be changed between left and right depending on whether the subject's eye is the right eye or the left eye. Because there is. This is because the slit light is projected from the oblique direction to the subject's eye, so that the slit light is moved from the center side of the pupil to the outer corner of the eye so that the slit light is not blocked by the nose. . Note that, depending on the incident angle of the slit light, the moving direction of the slit light can be from the center of the pupil to the inner corner of the eye.
In the present embodiment, the angle at which the slit light is projected to the eye to be inspected is set to 60 °, but the angle at which the slit light is projected to the visual axis of the eye to be inspected can be appropriately set. However, when the projection angle of the slit light is changed, it is necessary to analyze the data when analyzing the anterior chamber depth in consideration of the fact that the projection angle has changed.

In FIG. 3, a microscope 36 and a CCD camera 40 constitute a photographing optical system that photographs a cross-sectional image of an anterior segment of an eye to be examined.
The microscope 36 is for visually recognizing a cross-sectional image of the eye to be inspected as an enlarged image, and is fixed to an upper portion of a support arm 38 so as to face the eye to be inspected. The CCD camera 40 is arranged behind the microscope 36. The CCD camera 40 is for taking a cross-sectional image of the cornea and the iris of the anterior segment by the microscope 36. Since the distance between the cornea and the iris is as wide as about 5 mm, the CCD camera 40 must have a sufficient depth of focus so that a cross-sectional image of the cornea and the iris can be focused and photographed. In the present embodiment, based on the principle of Scheimpflug, the imaging optical axis of the CCD camera 40 is inclined (floated) by a predetermined angle with respect to the optical axis of the microscope 36, and the cross-sectional images of the cornea and the iris are simultaneously focused and photographed. It is arranged to be able to.

  In order to arrange the CCD camera 40 so that its optical axis position is inclined at a predetermined angle with respect to the optical axis of the microscope 36, in this embodiment, the slit lamp 34 and the photographing optical system are connected by the link arm 42. When the slit lamp 34 is set to the right position or the left position, the optical axis of the CCD camera 40 is linked to the position of the slit lamp 34 at a predetermined angle with respect to the optical axis of the microscope 36 so as to be set. I have to. In practice, the optical axis of the CCD camera 40 is tilted counterclockwise when the slit lamp 34 is on the right side of the subject, and when the slit lamp 34 is on the left side of the subject. The optical axis of the camera 40 is linked so as to be inclined clockwise.

Reference numeral 44 denotes a gantry that constitutes a fine movement positioning mechanism for positioning the subject's eye and the optical system, 46 denotes a joystick for performing a positioning operation, and 48 denotes a support base. 50 is a slide guide attached to the upper part of the support base 48.
The base end of the support arm 38 is supported by a support base 48 via a slide guide 50, and the slit lamp 34 is also supported by the support base 48 via a slide guide 50 on the base end side. The slit lamp 34 is pivotally supported so as to be able to move its position to the left and right positions, and the left and right rotation positions of the slit lamp 34 are regulated by the stopper, so that the projection angle of the slit light to the eye to be examined is set. It has become so.

  The slide guide 50 moves the slit lamp 34 and the photographing optical system in the left-right direction toward the subject, in other words, in a direction perpendicular to the visual axis of the subject's eye (the moving direction of the photographing system and the slit light in FIG. 1). In such a way as to perform the guiding operation. In the present embodiment, the entirety of the slit lamp 34 and the photographing optical system supported by the slide guide 50 is moved along the slide guide 50 by rotating the ball screw by a driving motor (not shown) for movement. I try to make it. Note that the distance for moving the slit lamp 34 and the photographing optical system in one measurement is about 8 mm. The slide guide, the slit lamp 34, the drive motor for moving the photographing optical system, and the like constitute a moving mechanism of the optical system.

  The fine movement positioning mechanism is for positioning the slit light projection optical system and the photographing optical system with the subject's eye at the start of measurement. By tilting the joystick 46, the front, rear, left and right positions with respect to the subject's eye can be adjusted, and by rotating the joystick 46, the height position can be adjusted. After the optical system is positioned with respect to the eye of the subject by the fine movement positioning mechanism, the measurement is performed by moving the slit light projecting optical system and the photographing optical system in parallel.

Reference numeral 52 denotes a fixation lamp used to fix the subject at the time of measurement and to align the subject's eye with the optical system. By gazeing at the fixation lamp 52, the subject can prevent the subject's eye from moving during the measurement. The fixation lamp 52 is also used to align the optical system with the position of the subject's eye by aligning the spot light of the fixation lamp 52 with the center of the subject's pupil at the start of measurement. You.
Reference numeral 54 denotes a monitor provided for the examiner to see the state of the anterior segment of the subject's eye. An image of the anterior segment of the subject's eye is displayed on the monitor 54, and the examiner operates the fine movement positioning mechanism while looking at the monitor 54 to perform an operation of aligning the optical system with the subject's eye. It can be carried out. The spot light of the fixation lamp 52 is positioned at the center of the pupil of the subject's eye, and the state where the spot diameter is smallest is the aligned state.

At the top of the joystick 46, a switch button for ON-OFF control of a drive motor for guiding the slit light projection optical system and the photographing optical system to move the slide guide 50 by being guided by the slide guide 50 is provided. By pressing this switch button, the optical system moves so as to scan, and measurement of the anterior segment is performed.
Reference numeral 55 denotes a computer main body used for analyzing an image photographed by the CCD camera 40, 56 denotes a display for displaying a photographed image and an analysis result, 58 denotes a keyboard as input means, and 60 denotes a mouse.
The ophthalmic examination apparatus according to the present embodiment captures a cross-sectional image of the anterior eye of the subject into an image storage unit of a computer unit using an imaging optical system, and analyzes the cross-sectional image using an analysis unit such as image analysis software. Then, the analysis result is displayed on a display 56 as display means.

Hereinafter, an example in which the anterior chamber depth of a subject is actually measured using the above-described ophthalmic examination apparatus will be described.
When using the above-described ophthalmic examination apparatus, the examinee puts his / her face on the chin rest 32, urges the examinee to gaze at the fixation lamp 52, and then operates the joystick 46 while looking at the monitor 54. Then, the spot light of the fixation lamp 52 is aligned with the center of the pupil of the subject's eye. In this state, the slit light of the slit lamp 34 is projected toward the center of the pupil of the subject's eye from the direction of 60 ° with respect to the visual axis of the subject's eye, and the microscope 36 faces the center of the pupil of the subject's eye. I have.

  When the eye and the optical system are aligned, a switch button provided on the top of the joystick 46 is pressed. As a result, the slit lamp 34, the microscope 36, and the CCD camera 40 are guided by the slide guide 50 and move in parallel from the center of the pupil toward the periphery of the iris. As a result, the slit light moves from the center of the pupil toward the periphery of the iris so as to scan the anterior segment while maintaining a projection angle of 60 °. The time required for the slit lamp 34 and the imaging optical system to move so as to scan is about 0.5 seconds. By completing the examination in a short time, it is possible to prevent the swaying and blinking of the fixation and improve the measurement accuracy.

When the slit light projection optical system and the photographing optical system move, the computer main body 55 captures a cross-sectional image of the cornea and the iris as image data by the image storage unit, analyzes the image by the analysis unit, and measures the anterior chamber depth.
In the ophthalmic examination apparatus of the present embodiment, the distance that the slit light projection optical system and the imaging optical system move from the center of the pupil toward the periphery of the iris is 8 mm, and the cross section of the cornea and the iris is 0.4 mm apart. Set to capture images. As a result, 21 image data of 0 to 20 are captured in one scan. The image data captured from the CCD camera 40 is transferred to and stored in a memory, and image analysis processing is performed by image analysis software, and the result is displayed on a display 56.

4 to 7 show display screen examples on the display 56 for an actual measurement example. FIG. 4 is a diagram in which 21 pieces of image data 0 to 20 taken from the center of the pupil toward the periphery of the iris are arranged in order from the center of the pupil (upper side of the figure) to the periphery of the iris (lower side of the figure). It is displayed. In the figure, the part C that glows white shows the cross section of the cornea, and the right side gradually shifts from the center of the pupil toward the periphery of the iris because the cornea is curved. . From this, the degree of curvature of the cornea can be known, and the thickness of the cornea can be analyzed from the cross-sectional width (white portion) of the cornea.
The part I that glows white behind the cornea is an image of the iris. From the cross-sectional image of the iris, it is understood that the iris is located at a predetermined interval behind the cornea, and that the distance from the cornea becomes narrower as approaching the periphery of the iris.

  FIG. 5 is an example of a display screen showing, as a graph, numerical data on the anterior chamber depth, the corneal thickness, the ratio of the anterior chamber depth to the corneal thickness after image analysis, and the anterior chamber depth. As can be seen from the anterior chamber depth graph, the anterior chamber depth gradually narrows from the center of the pupil toward the periphery of the iris, and is similar to the qualitative graph shown in FIG. The display screen shown in FIG. 4 is provided with a column for entering necessary accompanying data such as a measurement date, a subject name, and a comment, so that the related data is recorded together with the measurement data of the subject. It is configured.

The display screen shown in FIG. 6 is an example in which the relative positional relationship between the cornea and the iris is graphically displayed on the screen. The arc-shaped curves indicate the outer and inner surfaces of the cornea, and the position of the iris is drawn inside the cornea.
In this way, by graphically displaying the position of the iris based on the positional relationship with the cornea, the positional relationship between the cornea and the iris, that is, an example in which the interval between the cornea and the iris is relatively large (wide angle angle) It is easy to see whether the distance between the eye and the cornea and the iris is narrow (narrow-angle eye). The measurement examples shown in FIGS. 4 to 6 are examples of a subject with a wide-angle eye.

7 to 9 show measurement examples of a subject having a narrow interval between the cornea and the iris (a narrow-angle eye). Comparing the image data shown in FIG. 7 with the image data shown in FIG. 4, it can be seen that in the case of this subject, the distance between the cornea and the iris is narrow.
The numerical data obtained by analyzing the image data shown in FIG. 8 and the graph of the anterior chamber depth indicate that the anterior chamber depth is considerably narrow. The difference is clear when compared with the data of the wide-angle eye shown in FIG. Also, the results of drawing the cornea and the iris shown in FIG. 9 in a drawing show that the anterior chamber depth is smaller than that in the example shown in FIG.

  As described above, according to the ophthalmic examination apparatus of the present embodiment, the shape of the anterior segment of the subject, particularly the distance between the cornea and the iris (the depth of the anterior chamber) is obtained using the slit light projection optical system and the imaging optical system. ) Can be measured easily and with high accuracy, and based on the measurement results, can be suitably used for examination of ophthalmic diseases. In particular, the ophthalmic examination apparatus and the ophthalmic examination method of the present embodiment have the advantage of enabling quantitative comparison of measurement data and the ability to see corners that are difficult to see by ordinary ophthalmic examination. There is an advantage that can be. Since this ophthalmic examination apparatus can examine the shape of the anterior segment of the eye to be examined, it can be effectively used for examining ophthalmic diseases in addition to diseases such as closed-angle glaucoma.

  FIG. 10 shows a wide-angle eye, a narrow-angle eye, an example with a high possibility of onset (before LI), and each example of a plateau iris from measurement data obtained by measuring the anterior chamber depth using the ophthalmic examination apparatus. It is shown. The wide-angle eye in the illustrated example is an example in which the anterior chamber depth is very wide, and the narrow-angle eye is an example in which the anterior chamber depth is narrow. As shown in the graphs of the wide-angle eye and the narrow-angle eye, the healthy eye gradually decreases the anterior chamber depth as it approaches the periphery of the iris from the center of the pupil. Although there is an individual difference in the value of the anterior chamber depth, in the case of a healthy eye, it is considered that a graph in which the anterior chamber depth gradually decreases as approaching the periphery of the iris is obtained.

On the other hand, the graph illustrated as a high possibility of onset is a measurement example for the opposite eye of a subject who has already had a glaucoma attack, in this case, the anterior chamber depth is reduced as a whole and the iris The depth of the anterior chamber is sharply reduced at the position before approaching the periphery. Thus, if the depth of the anterior chamber is sharply reduced before reaching the periphery of the iris, it is considered that there is a risk of onset.
The plateau iris is a subtype of closed-angle glaucoma in which the depth of the anterior chamber at the center is relatively deep but the depth at the corner is very narrow. The measurement result of the plateau iris also shows that the depth of the anterior chamber is clearly narrower as approaching the peripheral portion of the iris as compared with the narrow-angle eye. The plateau iris is a symptom that is often overlooked even in ophthalmic medical treatment by a specialist, but according to this ophthalmic examination apparatus, it is possible to clearly know the symptom from the measurement result of the anterior chamber depth.

11 and 12 are explanatory views showing the configuration of another embodiment of the ophthalmologic examination apparatus according to the present invention. The above-described ophthalmic examination apparatus is used by manually operating the joystick 46 in order to align the slit light of the examination apparatus with the eye to be inspected. The ophthalmologic examination apparatus of the present embodiment makes it possible to automatically align the eye to be examined and the optical system of the examination apparatus, and also facilitates switching between the examination of the right eye and the left eye, and easily and reliably at the examination level. Inspection is possible.
FIG. 11 is an explanatory view showing the arrangement of the slit light projection optical system and the photographing optical system in the present embodiment, and FIG. 12 shows the planar arrangement of the slit light projection optical system and the photographing optical system. As shown in FIG. 11, in the present embodiment, the slit light projection optical system is provided independently for the right eye and the left eye, and the slits for the right eye are respectively provided according to the right eye inspection and the left eye inspection. The light projection optical system 60a and the slit light projection optical system 60b for the left eye are configured to be used.

  As shown in FIG. 12, the slit light projection optical systems 60a and 60b include a halogen lamp 62 as a light source for projecting slit light, an optical system 64 having a plurality of optical lenses, a slit 66, and a mirror 68. These slit light projection optical systems 60a and 60b are set so that the slit light is projected from a direction inclined at a predetermined angle with respect to the visual axis of the eye to be inspected. The projection direction of the slit light to the eye to be examined is fixed.

The photographing optical system is disposed at a center position between a pair of slit light projection optical systems 60a and 60b disposed on the left and right. The photographing optical system includes a microscope 36 and a CCD camera 40 as in the above-described embodiment. FIG. 12 shows that the CCD camera 40 is disposed at an appropriate angle to the optical axis. The position of 1 is the direction of the camera at the time of the auto alignment operation for aligning the slit light with the eye to be examined, 2 is the direction of the camera when using the slit light projection optical system 60b for the left eye, and 3 is the direction of the camera for the right eye. This shows the direction of the camera when the slit light projection optical system 60a is used.
Reference numeral 52 denotes a fixation lamp. In the present embodiment, as shown in FIG. 12, an LED 70 that emits visible light is used as a light source of a fixation lamp, and the visible light is emitted toward a subject's eye via a mirror 72. 52 is configured to be visible.

  As shown in FIG. 11, in the ophthalmologic examination apparatus of the present embodiment, these slit light projection optical systems 60a and 60b and the entire photographing optical system are supported on a control stage 80, and the control stage 80 is moved in the X-Y direction and By controlling the movement in the Z direction, alignment and required inspection are performed. The XY direction refers to a moving direction in a horizontal plane, and the Z direction refers to a moving direction in a vertical direction. The X direction is a direction in which the eye moves in the left-right direction (the direction in which the slit light is scanned) with respect to the eye to be examined. The Y direction is a direction in which the eye moves vertically with respect to the subject's eye, and is set to move ± 15 mm in the present embodiment. Further, it is set so as to move ± 15 mm in the Z direction.

In the present embodiment, the slit light projecting optical systems 60a and 60b, the photographing optical system, and the fixation lamp 52 are housed in a black box, and the box itself is movable in the XY directions and the Z directions. It has a dual purpose. Of course, the control stage 80 supporting the slit light projection optical systems 60a and 60b, the photographing optical system, and the fixation lamp 52 is housed in a box (housing) of the ophthalmic examination apparatus, and the movement of the control stage 80 is controlled. Is also good.
The control stage 80 regulates the movement direction of the control stage 80 in the XY direction and the Z direction by a slide guide, and can control the movement by a ball screw and a drive motor that rotationally drives the ball screw.

(Alignment operation)
In the ophthalmologic examination apparatus of the present embodiment, the operation of automatically matching the center position of the optical system with the vertex position of the cornea of the eye to be examined can be performed based on the principle shown in FIG. That is, in the ophthalmologic examination apparatus of the present embodiment, the slit light projection optical system 60a for the right eye and the slit light projection optical system 60b for the left eye are arranged at symmetrical positions. The alignment can be performed by projecting the alignment light from the projection optical system 60a and the slit light projection optical system 60b for the left eye toward the subject's eye, and detecting the alignment light reflected from the cornea.

FIG. 13 shows the state in which the alignment light from the left and right slit light projection optical systems 60a and 60b is focused behind the cornea of the subject's eye. In this case, the alignment light incident from the right is on the right. Returning, the alignment light incident from the left returns to the left. On the other hand, FIG. II shows a state in which the alignment light from the left and right slit light projection optical systems 60a and 60b is focused in front of the cornea of the subject's eye. In this case, the alignment light incident from the right is reflected to the left. Then, the alignment light incident from the left is reflected to the right. Thus, by detecting the reflected light from the cornea, it is possible to determine whether the optical system is focused in front of or behind the cornea. Therefore, the control stage 80 can be moved back and forth based on the detection result. Thereby, the focus positions of the left and right slit light projection optical systems 60a and 60b can be made coincident with the top of the cornea.

  FIG. 13 shows an operation in which the center position of the optical system of the inspection apparatus coincides with the center of the eye to be inspected, and the focus positions of the left and right slit light projection optical systems 60a and 60b coincide with the vertices of the cornea. . When the center position of the optical system of the inspection apparatus is shifted left and right with respect to the vertex of the cornea, the reflection intensity of the alignment light incident on the subject's eye from the right and the reflection intensity of the alignment light incident from the left on the left and right are uneven. Can be detected. When the left and right positions of the optical system of the inspection apparatus are symmetrical, the reflected light intensities on the left and right become uniform as shown in FIG. Also, if the vertical position of the alignment light is misaligned with respect to the optical axis of the eye to be inspected, the reflected light from the cornea of the eye to be inspected is displaced above or below the incident height position of the alignment light. It is possible to detect that the optical axis of the subject's eye and the height position of the alignment light are misaligned.

Thus, by projecting the alignment light from the left and right to the eye to be inspected, detecting the reflected light reflected from the cornea of the eye to be inspected, and controlling the movement of the control stage 80 based on the detection result, the left and right slit light projection is performed. The focus positions of the optical systems 60a and 60b can be automatically made to coincide with the center position of the cornea of the eye to be examined.
In the ophthalmologic examination apparatus of the present embodiment, first, the XY direction of the optical system of the examination apparatus is aligned with the visual axis of the eye to be inspected, and then the Z direction of the optical system of the examination apparatus is aligned. I have.

  In FIG. 12, reference numeral 90 denotes an LED that emits red light or infrared light used as a light source for alignment light, 92 denotes a slit, and 94 denotes a half mirror. In this embodiment, the left and right slit light projection optical systems 60a and 60b are used to make the alignment light incident on the eye to be inspected, and the CCD camera 40 detects the reflected light from the eye to be inspected. In the case of this embodiment, there is an advantage that the configuration of the alignment optical system can be simplified by using the slit light projection optical systems 60a and 60b as the alignment optical system. The LED light source used as the alignment light source can be easily turned on and off at a predetermined frequency, thereby improving the S / N ratio of the detection signal and enabling accurate alignment.

  FIG. 14 shows an example in which the optical system for the alignment light is provided separately from the left and right slit light projection optical systems 60a and 60b. 90 is an LED, 92 is a slit, and 93 is a mirror. Alignment optical systems 95a and 95b are provided at symmetric positions of the center line of the inspection apparatus with respect to the eye to be inspected, and alignment light is projected from each of the alignment optical systems 95a and 95b toward the eye to be inspected from an oblique direction. Is configured to detect reflected light from the subject's eye. In the case of the apparatus shown in FIG. 12, since the half mirror 94 is used, the intensity of the alignment light is weakened, whereas in the case of the present embodiment, the alignment optical system is provided separately from the slit light projection optical systems 60a and 60b. Since it is provided, there is an advantage that alignment can be performed using alignment light of a required intensity.

  FIG. 15 shows still another configuration example of the alignment optical system. An LED 90 and a mirror 93 are provided on one side of the slit light projection optical systems 60a and 60b so that the alignment light is made incident on the eye to be examined. A lens 96 and a mirror 97 are provided on the other side of the projection optical systems 60a and 60b, and the CCD camera 40 detects reflected light from the eye to be inspected. In the case of the present embodiment, alignment can be performed by matching the reflected light from the eye to be inspected with the alignment light from the alignment optical system, so that only one alignment light source can be used. Reference numeral 98 denotes a beam splitter provided to detect an image obtained by the imaging optical system (CCD camera) and an image obtained by the alignment optical system.

(Scan measurement)
The scan measurement is performed by moving the focus position of the optical system of the inspection apparatus to the vertex position of the cornea of the eye to be inspected, and moving the optical system of the inspection apparatus to a predetermined distance (3.9 mm in the present embodiment) at the back side of the eye. By scanning (moving in the X direction) the optical system from the moved position, slit light is scanned from the center of the pupil to the periphery of the iris for inspection. FIG. 16A shows a state in which the focus position of the optical system of the inspection apparatus is moved by 3.9 mm from the cornea vertex of the eye to be inspected. As described above, the control stage 80 is movable in the X direction, and scan measurement can be performed by moving the control stage 80 in the X direction.
The measurement is performed using the slit light projection optical system 60a for the right eye or the slit light projection optical system 60b for the left eye according to the measurement of the right eye or the left eye. In the ophthalmologic examination apparatus of the present embodiment, the examination of the right eye or the left eye can be performed only by selecting the left and right slit light projection optical systems 60a and 60b, so that the switching operation of the left and right eyes can be easily performed.
In addition, the ophthalmologic examination apparatus according to the present embodiment can automatically and accurately align the optical system of the examination apparatus with the center of the cornea (center of the pupil) of the eye to be examined. It becomes possible to inspect in time.

(Measurement of central corneal thickness)
The thickness of the cornea at the central position of the eye to be examined is, as shown in FIG. 16 (b), when the optical system of the inspection apparatus is aligned with the central position of the cornea of the eye to be inspected by using the alignment light. The measurement can be performed by projecting slit light from the optical systems 60a and 60b and capturing an image at that time. In practice, it is obtained by converting the thickness of the cornea from the data obtained from the image.
In the measurement of the central thickness of the cornea, it is necessary to accurately detect the vertex position of the cornea of the eye to be examined. However, in the ophthalmic examination apparatus of the present embodiment, as described above, the vertex position of the cornea using the alignment light is used. Can be accurately detected, thereby obtaining an accurate inspection result without variation.

(Measurement of corneal curvature radius)
The radius of curvature of the cornea is measured from a state shown in FIG. 16B, that is, a state in which the vertex position of the cornea of the eye to be examined coincides with the focus position of the optical system of the examination apparatus (in this embodiment, 3. 9 mm) Measurement is performed by capturing an image at a position where the optical system of the inspection apparatus is moved to the far side of the eye to be inspected. FIG. 16A shows a state where the optical system of the inspection apparatus is moved by 3.9 mm from the vertex of the eye to be inspected.
FIG. 17 is an enlarged view showing a state in which the slit light has moved to the back side by D from the vertex position of the cornea with respect to the subject's eye. In the figure, the slit light 2 is a slit light in a state where the optical system of the inspection apparatus is moved, and the slit light 2 is virtually extended, and an extension line until it intersects the z axis is a, and the z axis direction. Is the length of b, the length of a in the y-axis direction is h, and the angle between a and the z-axis is θ. Let z be the length in the z-axis direction from the apex of the cornea until the slit light 2 enters the eye.

z can be obtained from b and the movement amount D of the optical system of the inspection apparatus, and the radius of curvature R of the cornea can be obtained from D, h, and θ by the following equation.
That is, b = h / tan θ, c = R−z, R ² −h ² = c ² → R ² −h ² = (R−z) ² → R = (z ² + h ² ) / 2z = ((D −h / tan θ) ² + h ² ) / 2 (D−h / tan θ)
The values of D, h, and θ are obtained by converting image data. Thus, the radius of curvature of the cornea can be determined.

The above-described measurement of the thickness of the central cornea and the measurement of the radius of curvature of the cornea can be performed in parallel with the scan measurement, and by performing these measurements together with the scan measurement, the situation of the eye to be examined is further increased. Can be detected with high accuracy,
As described above, according to the ophthalmic examination apparatus and the examination method using the same according to the present invention, the shape of the anterior segment of the subject's eye can be inspected as a quantitative data with a very clear shape. This makes it possible to easily detect an ophthalmic disease. In particular, at the time of examination, there is no need to perform operations that can only be performed by a specialist, such as using a lens for examination, so that it can be sufficiently handled by ordinary medical technicians and is suitable as an examination device for ophthalmologic diseases at the examination level It can be used for In addition, since no burden is imposed on the subject for the examination and the examination time is short, the apparatus can be provided as an easy-to-check device.

It is explanatory drawing which shows the cross-section of an eye. It is a graph which shows the anterior chamber depth with respect to the distance from a pupil. It is an explanatory view showing the whole composition of one embodiment of an ophthalmic examination device. FIG. 9 is an explanatory diagram illustrating an example of a screen display of image data with a wide-angle eye. It is explanatory drawing which shows the example of a screen display of the display which shows the numerical data of the anterior chamber depth and the graph of the anterior chamber depth in a wide-angle eye. It is explanatory drawing which shows the example of a screen display which displayed the cornea and the iris in a wide-angle eye in a figure. FIG. 9 is an explanatory diagram illustrating an example of a screen display of image data with a narrow-angle eye. It is explanatory drawing which shows the example of a screen display of the display which shows the numerical data of the anterior chamber depth and the graph of the anterior chamber depth in a narrow-angle eye. It is explanatory drawing which shows the example of a screen display which displayed the cornea and the iris in a narrow-angle eye in a figure. It is a graph which shows the example of measurement of an anterior chamber depth. It is an explanatory view showing arrangement of an optical system in other embodiments of an ophthalmic examination device. It is explanatory drawing which shows planar arrangement | positioning of the optical system in other embodiment of an ophthalmic examination apparatus. FIG. 4 is an explanatory diagram illustrating a method of aligning with a vertex of a cornea of an eye to be examined. It is an explanatory view showing another example of an alignment optical system of an ophthalmic examination device. It is explanatory drawing which shows another example of the alignment optical system of an ophthalmic examination apparatus. FIG. 3 is an explanatory diagram showing a state in which the optical system is moved from a vertex position of a cornea. It is explanatory drawing which shows the method of measuring the curvature radius of a cornea.

Explanation of reference numerals

Reference Signs List 10 cornea 12 iris 14 crystalline lens 17 ciliary body 18 anterior chamber 20 posterior chamber 30 support table 34 slit lamp 34a mirror 36 microscope 38 support arm 40 CCD camera 42 link arm 46 joystick 50 slide guide 52 fixation lamp 54 monitor 55 computer body 56 display 60a, 60b slit light projection optical system 62 halogen lamp 80 control stage 95a, 95b alignment optical system

Claims (7)

An ophthalmic examination apparatus for examining an ophthalmologic disease of an eye to be inspected by detecting a cross-sectional shape of an anterior segment of an eye to be inspected,
A slit light projection optical system that projects while moving to scan the slit light from the pupil region to the peripheral portion of the iris toward the anterior segment of the eye to be examined,
A photographing optical system for photographing a cross-sectional image of the anterior segment obtained by the projection light projected by the slit light projection optical system,
An ophthalmic examination apparatus, comprising: a computer for analyzing a cross-sectional image captured by the imaging optical system and analyzing a shape of an anterior segment of an eye to be inspected. The ophthalmologic examination apparatus according to claim 1, wherein the slit light projection optical system is provided to project the slit light from an oblique direction with respect to the visual axis of the eye to be inspected. The slit light projection optical system is provided such that the projection position of the slit light can be set to a left position and a right position toward the subject depending on whether the subject's eye is the right eye or the left eye. Item 3. An ophthalmic examination apparatus according to Item 2. The slit light projection optical system is provided to project slit light from an oblique direction in which the projection angle is fixed with respect to the visual axis of the subject's eye,
2. The moving mechanism for moving the slit light projecting optical system together with the photographing optical system in a direction for moving the slit light from the pupil of the eye to be examined toward the peripheral part of the iris, according to claim 1, wherein Ophthalmic examination device. The ophthalmologic examination apparatus according to claim 1, wherein the imaging optical system includes a microscope that magnifies and visually recognizes a cross-sectional image of the anterior segment of the eye to be inspected, and a CCD camera that captures the cross-sectional image. A fixation lamp for aligning the eye to be inspected with the optical system of the inspection apparatus, and a fine movement alignment mechanism for finely adjusting the left and right position and the height position of the optical system by operating the joystick. The ophthalmic examination apparatus according to claim 1, 2, 3, 4 or 5. When the computer unit is moved to scan the slit light from the pupil region to the periphery of the iris, image storage means for capturing and storing a cross-sectional image of the anterior segment at predetermined intervals,
Analysis means for analyzing the shape of the anterior segment by image analysis of each cross-sectional image recorded by the image storage means,
The ophthalmic examination apparatus according to claim 1, further comprising a display unit that displays a result analyzed by the analysis unit.

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