JP3878164B2 - Ophthalmic examination equipment - Google Patents

Description

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

  Glaucoma is a disease in which the optic nerve is affected mainly due to an increase in intraocular pressure, resulting in abnormal visual field and decreased visual acuity, and is a disease that is one of the top causes of blindness in ophthalmology. Epidemiological studies indicate that the estimated number of glaucoma patients in Japan is between 3 and 4 million. However, in most cases, glaucoma is diagnosed and treated by an ophthalmologist for the first time after it develops, and in the case of ophthalmic treatment, it is possible to find a patient who may have glaucoma. At present, there is no pre-examination of people who are at risk of developing.

FIG. 1 shows a cross-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 the iris mainly functions to adjust the amount of input light, 14 is a crystalline lens, and 16 is a jelly-like transparent film. Vitreous body consisting of various tissues. The crystalline lens 14 is supported so as to be suspended from the ciliary body 17 via a chin band.
A region surrounded by the cornea 10, the lens 14, and the iris 12 is called an anterior chamber 18, and a portion surrounded by the iris and vitreous body is called an posterior chamber. The anterior chamber 18 and the posterior chamber 20 are filled with transparent aqueous humor. Aqueous humor carries oxygen and nutrients to each tissue in the eye and carries waste from each tissue in the eye to the outside of the eye. The aqueous humor is produced by the ciliary body 17 and is transferred from the posterior chamber 20 to the anterior chamber 18. After being circulated toward the center, the blood is discharged into the vein from a corner portion (A portion in the figure: called 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 excretion of aqueous humor. That is, when the aqueous humor discharge capacity decreases or the production capacity increases, the intraocular pressure increases. Conversely, when the discharge capacity increases or the production capacity decreases, the intraocular pressure decreases. Glaucoma is most often caused by a decrease in the amount of aqueous humor that drains out of the eye, thereby increasing intraocular pressure, rather than by increasing the amount of aqueous humor. . Since the amount of aqueous humor produced is almost constant in the ciliary body regardless of the amount discharged outside the eye, the intraocular pressure increases when the amount of aqueous humor discharged from the corner is suppressed.

  The reason why the amount of aqueous humor discharged outside the eye decreases and the intraocular pressure increases can be attributed to the aqueous humor in the mesh tissue, trabecular meshwork formed at the corner where the aqueous humor is discharged. When the aqueous humor is difficult to be discharged (open-angle glaucoma), the corner itself is inherently narrow, and for some reason a pressure difference between the anterior chamber 18 and the posterior chamber 20 occurs. 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 (a closed angle glaucoma).

Open-angle glaucoma has a slow increase in intraocular pressure, and the symptoms progress slowly, whereas closed-angle glaucoma suddenly increases intraocular pressure by closing the outlet of the 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-attack angle glaucoma have no subjective symptoms, and in particular, closed-angle glaucoma has the property that the symptoms progress rapidly when onset. Pre-diagnosis is extremely important.
Of these open-angle glaucoma and closed-angle glaucoma, open-angle glaucoma is very difficult to diagnose from the corner findings because the shape of the corner part is very similar to that of healthy subjects. The angle of the anterior chamber and the depth of the anterior chamber are examined, and if the interval is narrow, glaucoma can be prevented from occurring by treating it with the possibility that angle-closure glaucoma may develop. Is possible.

  However, it is not always easy to diagnose angle-closure glaucoma in ophthalmic practice. When diagnosing whether or not it is a closed angle glaucoma, the interval between the cornea and the iris, especially the interval between the corners, will be examined, but the interval between the cornea and the iris varies from person to person and depends on the age. Since it changes, it is difficult for a specialist to determine whether there is a risk of developing simply by whether the interval is narrow or wide. In addition, in order to examine the distance between the cornea and the iris, a test lens (angle mirror) is applied to the cornea to visually confirm the shape of the anterior chamber part. It is not realistic to perform such specialized diagnostic tests.

In addition, the method of inspecting using the lens for inspection has a problem that the cornea is damaged by the lens or bacteria are infected from the lens because the lens for inspection is directly applied to the cornea. There is a problem that this is an inspection method that imposes a burden on Therefore, the method of inspecting using an inspection lens is actually performed by an ophthalmologist when there is a risk of glaucoma during ophthalmic treatment.
There is also a method of inspecting the interval between the cornea and the iris using slit light (slit lamp) without using an inspection lens, but this method is simply visualizing the interval between the cornea and the iris. It is only a qualitative evaluation of the width of the gap, and there is a problem that the accuracy is much lower than the method of diagnosis using a test lens, and the gap of the iris base (corner angle) is clearly defined The problem is that it is difficult to see and accurate diagnosis is difficult.

  Therefore, the present invention has been made to solve these problems, and the object of the present invention is to achieve closed angle glaucoma or anterior chamber without operation that must be performed by a specialist such as using a lens for examination. It is possible to test for ophthalmic diseases in the area, so that it can be tested without imposing a burden on the subject, it can be used even if it is not a specialist, and it is used for testing ophthalmic diseases such as glaucoma at the screening level 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 detecting an anterior chamber depth of an anterior eye portion of an eye to be examined to inspect an ophthalmic disease of the eye to be examined, directed toward the anterior eye portion of the eye to be examined, with respect to the visual axis of the eye to be examined Slit light projection optical system provided to project slit light from an oblique direction with a fixed projection angle, and photographing optics for photographing an anterior segment image obtained by the projection light projected by the slit light projection optical system And the slit light projection optical system is moved so that the slit light projected from the slit light projection optical system is scanned from the pupil region to the periphery of the iris while maintaining the projection angle, in synchronization with the slit light projection optical system, said imaging optical system, a moving mechanism for moving in parallel to the position directly facing the eye to the periphery of the iris together with the slit light projection optical system, for scanning, The An image that captures and stores an image of the anterior segment at every predetermined movement interval when the moving mechanism scans slit light from the pupil area to the periphery of the iris and captures an image of the anterior segment by the imaging optical system. A computer unit having storage means, analysis means for analyzing the image recorded by the image storage means to obtain the anterior chamber depth as quantitative measurement data, and display means for displaying the result of analysis by the analysis means It is characterized by having.

The front Symbol slit light projection optical system, that the subject's eye in response to the right eye or left eye, the projection position of the slit light is provided so as to be set on the left side position and the right position to the subject It is valid.

The front Symbol photographing optical system is characterized by comprising: a microscope for viewing an enlarged cross-sectional image of the anterior segment of the eye, and a CCD camera for photographing the cross-sectional image.

In addition, it has 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 height position of the optical system by operating the joystick. Accurate inspection is possible.

  The ophthalmic examination apparatus according to the present invention can detect the cross-sectional shape of the anterior ocular segment of the subject's eye as quantitative measurement data, thereby enabling the development of ophthalmic diseases of the subject, such as closed-angle glaucoma. It becomes possible to perform an accurate inspection for sex and the like. In addition, since it is not necessary to use an inspection lens for measurement, it can be handled without a specialist, and can be diagnosed with a high degree of reliability by performing an examination at the examination level. There are significant effects such as being able to be suitably used as a detecting device.

Summary of the Invention

The inspection method using the ophthalmic inspection apparatus according to the present invention is to inspect the cross-sectional shape of the anterior ocular segment by projecting slit light onto the eye of the subject and taking cross-sectional images of the cornea and iris of the eye. The measurement is performed remotely without using a special lens, and the symptoms are diagnosed based on the measurement result.
As described above, closed-angle glaucoma may be affected by observing the distance between the cornea and iris (anterior chamber depth) in the anterior chamber and measuring how the interval is. It is possible to diagnose whether or not there is.

In FIG. 1, the interval D indicates the anterior chamber depth. The anterior chamber depth D is wide 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 eye to be examined, the symptom can be objectively grasped based on the measurement result.
FIG. 2 is a graph showing the anterior chamber depth D qualitatively with the distance from the center of the pupil to the periphery of the iris as the horizontal axis and the anterior chamber depth D as the vertical axis. As shown in the figure, the cornea 10 and the iris 12 are wide open on the center side of the pupil, whereas the anterior chamber depth becomes narrower as the periphery of the iris 12 is approached. That is, the anterior chamber depth graph is a right-downward 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 depth is relatively deep (wide) and shallow (narrow) depending on the subject. There are individual differences such as. The inspection method according to the present invention accumulates data on healthy persons and onset persons about the anterior chamber depth, and statistically compares these data with measured values, for example, there is a risk of angle-closure glaucoma. It diagnoses whether or not there is. It is relatively easy to compare these data to determine a healthy person and a person who has a risk of developing the disease, and it is possible to easily diagnose at a screening level.
Since the inspection method according to the present invention can measure the anterior chamber depth as quantitative data, it is possible to make a much more objective diagnosis by computer processing of the data as compared with the inspection method by visual observation or the like. As a result, even a non-specialist can make a diagnosis and can be effectively used as a diagnosis method for a screening level.

  When it is diagnosed that there is a risk of angle-closure glaucoma by this examination method, a more accurate judgment can be obtained by receiving a diagnosis from a specialist, and an appropriate treatment can be taken. When there is a risk of developing closed-angle glaucoma, for example, the treatment of glaucoma can be avoided in advance by performing a treatment (laser iridotomy) that opens a through-hole using a laser in the periphery of the iris. 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 in the iris 12 for communicating the anterior chamber 18 and the posterior chamber 20. The onset of angle-closure glaucoma can be completely prevented. If such a treatment is performed, then it is possible to prevent the occurrence of closed angle glaucoma thereafter.

Thus, if the method of the present invention can detect, for example, the symptoms of angle-closure glaucoma, the onset of angle-closure glaucoma can be prevented in advance, which is extremely effective for prevention of ophthalmic diseases.
As mentioned above, it is estimated that there are about 3 to 4 million potential patients in Japan alone. If glaucoma can be detected in advance at the screening level for these potential patients, it will be extremely effective in preventing ophthalmic 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 an ophthalmic examination apparatus according to the present invention. The ophthalmic examination apparatus according to the present embodiment projects slit light onto the eye of a subject, and moves the slit light from the center side of the pupil toward the periphery of the iris while crossing the cornea and iris at predetermined intervals. An image is taken and the taken image is analyzed to measure the distance between the cornea and the iris.

In FIG. 3, 30 is a support table, and 32 is a chin rest attached to a side edge portion of the support table 30 that faces the subject. The subject puts his / her 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 that projects slit light onto the eyes of the subject. The slit lamp 34 has a light source built in at the top, and is configured such that slit light is projected toward the eye to be examined by a mirror 34a. The slit light is adjustable in slit width and slit length.

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

In the ophthalmic examination apparatus of the present embodiment, the slit light is set to be projected toward the eye to be examined from a position inclined 60 ° to the right or left from the normal viewing direction of the eye to be examined. The reason why the slit light is projected from the oblique direction to the eye to be examined is to allow the subject to measure the anterior chamber depth without feeling dazzling.
In addition, the slit light can be projected to the subject from the right direction or the left direction because the slit light projection direction needs to be changed between the left direction and the right direction depending on whether the subject 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 eye to be examined, 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. . Depending on the incident angle of the slit light, the moving direction of the slit light can be changed from the center side of the pupil to the eye side.
In the present embodiment, the angle at which the slit light is projected onto the eye to be examined is set to 60 °, but the angle at which the slit light is projected onto the visual axis of the eye to be examined can be appropriately set. However, when the projection angle of the slit light is changed, it is necessary to analyze the anterior chamber depth in consideration of the change in the projection angle when data is analyzed.

In FIG. 3, a microscope 36 and a CCD camera 40 constitute an imaging optical system that captures a cross-sectional image of the anterior segment of the eye to be examined.
The microscope 36 is for visually recognizing a cross-sectional image of the eye to be examined as an enlarged image, and is fixed to the upper part of the support arm 38 so as to face the eye to be examined. The CCD camera 40 is disposed behind the microscope 36. The CCD camera 40 is for taking a cross-sectional image of the cornea and iris of the anterior segment by the microscope 36. Since the distance between the cornea and the iris is as large 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. In the present embodiment, based on the principle of Shine-Pluke, the imaging optical axis of the CCD camera 40 is inclined at a predetermined angle with respect to the optical axis of the microscope 36, and the cross-sectional images of the cornea and iris are simultaneously focused. Arranged as possible.

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

Reference numeral 44 denotes a frame that constitutes a fine movement alignment mechanism that aligns the eye to be examined and the optical system, 46 a joystick that performs an alignment operation, and 48 a support base. Reference numeral 50 denotes a slide guide attached to the upper part of the support base 48.
The support arm 38 is supported at the base end by the support base 48 via the slide guide 50, and the slit lamp 34 is also supported at the base end by the support base 48 via the slide guide 50. The slit lamp 34 is pivotally supported so that the position of the slit lamp 34 can be moved to the left and right, and the projection position of the slit light with respect to the eye to be examined is set by restricting the left and right rotational positions of the slit lamp 34 by the stopper. It has become so.

  The slide guide 50 moves the slit lamp 34 and the imaging 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 imaging system and the movement direction of the slit light in FIG. 1). It is for making the effect | action which guides. In the present embodiment, the slit lamp 34 supported by the slide guide 50 and the entire photographing optical system are moved along the slide guide 50 by rotating the ball screw by a drive motor (not shown) for movement. I try to let them. Note that the distance that the slit lamp 34 and the photographing optical system are moved in one measurement is about 8 mm. A slide motor, a slit lamp 34, a drive motor for moving the photographing optical system, and the like constitute a moving mechanism of the optical system.

  The fine movement alignment mechanism is for aligning the slit light projection optical system and the imaging optical system with the eye of the subject at the start of measurement. By tilting the joystick 46, the front / rear and left / right positions with respect to the eye to be examined can be adjusted, and by rotating the joystick 46, the height position can be adjusted. After the optical system is aligned with the eye of the subject by the fine movement alignment mechanism, the slit light projection optical system and the photographing optical system are moved in parallel to perform measurement.

A fixation lamp 52 is used for fixing the subject at the time of measurement and aligning the eye and the optical system. The subject can keep the eye of the subject from moving during the measurement by gazing at the fixation lamp 52. 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 pupil of the subject at the start of measurement. The
A monitor 54 is 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 alignment mechanism while looking at the monitor 54 to perform an operation for 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 eye to be examined, and the state where the spot diameter is the smallest is the aligned state.

On the top of the joystick 46, there is provided a switch button for ON / OFF control of a drive motor guided by a slide guide 50 to move the slide light projection optical system and photographing optical system. By pressing this switch button, the optical system moves so as to scan and the anterior segment is measured.
Reference numeral 55 denotes a computer main body used for analyzing an image photographed by the CCD camera 40, 56 a display for displaying a photographed image and analysis results, 58 a keyboard as an input means, and 60 a mouse.
The ophthalmic examination apparatus according to the present embodiment captures a cross-sectional image of the anterior eye part of a 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. The analysis result is displayed on the display 56 as display means.

Below, the example which actually measured the subject's anterior chamber depth using the ophthalmic examination apparatus mentioned above is demonstrated.
When using the above-described ophthalmic examination apparatus, the subject puts his face on the chin rest 32 and prompts the subject 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 eye to be examined. In this state, the slit light of the slit lamp 34 is projected from the direction of 60 ° with respect to the visual axis of the eye to be examined toward the center of the pupil of the eye to be examined, and the microscope 36 is directed toward the center of the pupil of the eye to be examined. Yes.

  When the eye to be examined 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 photographing optical system to move so as to scan is about 0.5 seconds. By completing the inspection in a short time, it is possible to prevent shaking and blinking of the fixation, and increase the measurement accuracy.

In the computer main body 55, when the slit light projection optical system and the photographing optical system move, a cross-sectional image of the cornea and iris is captured as image data by the image storage means, and the anterior chamber depth is measured by image analysis by the analysis means.
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 at intervals of 0.4 mm. 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 the memory, and image analysis processing is performed by image analysis software, and the result is displayed on the display 56.

4 to 7 show examples of display screens on the display 56 for actual measurement examples. In FIG. 4, 21 image data of 0 to 20 captured 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. The portion C that shines in white in the figure shows the cross section of the cornea, and the reason that the portion gradually shifts to the right side from the center of the pupil to the periphery of the iris is because the cornea is curved. . From this, the degree of curvature of the cornea can be understood, and the thickness of the cornea can be analyzed from the cross-sectional width (white part) of the cornea.
The portion of I shining white behind the cornea is an iris image. From the cross-sectional image of the iris, it can be seen that the iris is positioned behind the cornea at a predetermined interval, and that the distance from the cornea becomes narrower as the periphery of the iris is approached.

  FIG. 5 is an example of a display screen showing numerical data on the anterior chamber depth after image analysis, the cornea thickness, and the ratio of the anterior chamber depth to the cornea thickness, and the anterior chamber depth as a graph. As can be seen from the anterior chamber depth graph, the anterior chamber depth gradually decreases 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 has columns for entering required accompanying data such as measurement date, subject name, comments, etc., so that related data is recorded along with the subject measurement data. 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. Curves drawn in an arc shape show the outer and inner surfaces of the cornea, and the iris position is drawn inside the cornea.
In this way, by graphically displaying the position of the iris based on the positional relationship with the cornea, is the positional relationship between the cornea and the iris, that is, whether the interval between the cornea and the iris is a relatively wide example (wide angle? Eye), or whether the distance between the cornea and the iris is narrow (a narrow-angle eye). The measurement examples shown in FIGS. 4 to 6 are examples of subjects with wide-angle eyes.

7 to 9 show measurement examples of a subject having a narrow gap between the cornea and the iris (narrow-angled eyes). When the image data shown in FIG. 7 is compared with the image data shown in FIG. 4, it can be seen that in this subject, the distance between the cornea and the iris is narrow.
From the numerical data obtained by analyzing the image data shown in FIG. 8 and the graph of the anterior chamber depth, it can be seen that the anterior chamber depth is quite narrow. The difference is clear when compared with the wide-angle eye data shown in FIG. In addition, it can be seen from the result of drawing the cornea and iris shown in FIG. 9 that the anterior chamber depth is narrower than the example shown in FIG.

  As described above, according to the ophthalmic examination apparatus of the present embodiment, the slit light projection optical system and the imaging optical system are used to form the shape of the anterior segment of the subject, particularly the distance between the cornea and the iris (anterior chamber depth). ) Can be measured easily and with high accuracy, and can be suitably used for screening ophthalmic diseases based on the measurement results. In particular, the ophthalmic examination apparatus and the ophthalmic examination method of the present embodiment allow the measurement data to be compared quantitatively, and also sees corner portions that are difficult to see in normal ophthalmic examinations. There is an advantage that can be. Since this ophthalmic examination apparatus can inspect the shape of the anterior segment of the eye to be examined, it can be effectively used to examine ophthalmic diseases in addition to diseases such as closed angle glaucoma.

  FIG. 10 shows examples of wide-angle eyes, narrow-angle eyes, cases with a high possibility of onset (before LI), and plateau irises from measurement data obtained by measuring the depth of the anterior chamber 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 wide-angle eye graph and the narrow-angle eye graph, the normal eye depth gradually decreases from the center of the pupil toward the periphery of the iris. Although there are individual differences in the value of the anterior chamber depth, it is considered that a normal eye can be obtained as a graph in which the anterior chamber depth gradually narrows as it approaches the periphery of the iris.

On the other hand, the graph shown as an example with a high possibility of onset is a measurement example of the opposite eye of a subject who has already had a glaucoma attack. In this case, the depth of the anterior chamber is reduced as a whole, and the iris The anterior chamber depth suddenly narrows at a position before approaching the periphery. Thus, it is considered that there is a risk of onset when the anterior chamber depth suddenly narrows before reaching the periphery of the iris.
The plateau iris is a subtype of closed angle glaucoma in which the depth of the corner portion is very narrow although the anterior chamber depth in the center is relatively deep. Also in the measurement results for this plateau iris, it can be seen that the anterior chamber depth is clearly narrower than the narrow-angle eye as it approaches the periphery of the iris. The plateau iris is a symptom that is often overlooked in ophthalmic practice 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 is an explanatory diagram showing a configuration of another embodiment of the ophthalmologic examination apparatus according to the present invention. The above-described ophthalmic examination apparatus uses the joystick 46 by manually operating it in order to align the slit light of the examination apparatus with the eye to be examined. The ophthalmic examination apparatus according to the present embodiment can automatically align the eye to be examined and the optical system of the examination apparatus, and can easily switch between examination of the right eye and the left eye, easily and reliably at the examination level. It can be inspected.
FIG. 11 is an explanatory diagram showing the arrangement of the slit light projection optical system and the photographing optical system in this 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 this embodiment, the slit light projection optical system is provided separately for the right eye and for the left eye, and each of the slits for the right eye is used according to the right eye inspection and the left eye inspection. The light projection optical system 60a and the left eye slit light projection optical system 60b are 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 including 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 by a predetermined angle with respect to the visual axis of the eye to be examined. The projection direction of the slit light with respect to the eye to be examined is fixed.

The photographing optical system is disposed at a central position between a pair of slit light projection optical systems 60a and 60b disposed on the left and right. The imaging 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 with respect to the optical axis. The position of 1 is the orientation of the camera at the time of auto alignment operation for aligning the slit light to the eye to be examined, 2 is the orientation of the camera when using the slit light projection optical system 60b for the left eye, and 3 is for the right eye The direction of the camera when using the slit light projection optical system 60a is shown.
Reference numeral 52 denotes a fixation lamp. In the present embodiment, as shown in FIG. 12, the LED 70 that emits visible light is used as a light source of the fixation lamp, and the subject is irradiated with the visible light through the mirror 72. 52 is configured to be visible.

As shown in FIG. 11, in the ophthalmic examination apparatus according to the present embodiment, the slit light projection optical systems 60a and 60b and the entire photographing optical system are supported on the control stage 80, and the control stage 80 is moved in the X and Y directions. By performing movement control in the Z direction, alignment and required inspection are performed. The XY direction refers to the moving direction in the horizontal plane, and the Z direction refers to the moving direction in the vertical direction. The X direction is a direction that moves in the left-right direction (direction in which slit light is scanned) with respect to the eye to be examined. In the present embodiment, the X direction is set to move about 100 mm to the left and right. The Y direction is a direction that moves in the front-rear direction with respect to the eye to be examined, and is set to move ± 15 mm in this embodiment. Further, it is set to move ± 15 mm in the Z direction.

In the present embodiment, the slit light projection optical systems 60a and 60b, the photographing optical system, and the fixation lamp 52 are housed in a black box, the box itself is movable in the XY direction and the Z direction, and the box is controlled by the control stage 80. It is also used as a combination. 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. Also good.
The control stage 80 can be controlled to move by a drive motor that restricts the movement direction of the control stage 80 in the XY direction and the Z direction by a slide guide, and rotationally drives the ball screw and the ball screw.

(Alignment operation)
In the ophthalmic examination apparatus of the present embodiment, the operation of automatically matching the center position of the optical system with the apex position of the cornea of the eye to be examined can be performed based on the principle shown in FIG. In other words, in the ophthalmic examination apparatus according to 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 left and right symmetrical positions. Alignment can be performed by a method of projecting alignment light from the projection optical system 60a and the slit light projection optical system 60b for the left eye toward the eye to be examined and detecting the alignment light reflected from the cornea.

FIG. 13 shows a 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 eye to be examined. In this case, the alignment light incident from the right is on the right side. 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 eye to be examined. In this case, the alignment light incident from the right is reflected to the left side. The alignment light incident from the left side is reflected to the right side. In this way, by detecting the reflected light from the cornea, it can be determined whether the optical system is focused in front of the cornea or in the rear, so that the control stage 80 is moved back and forth based on the detection result. Thus, 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 examined, and the focus positions of the left and right slit light projection optical systems 60a and 60b coincide with the vertexes of the cornea. . When the center position of the optical system of the inspection device is shifted left and right with respect to the apex of the cornea, the reflection intensity of the alignment light incident from the right and the alignment light incident from the left on the eye to be examined is uneven. Can be detected. When the left and right positions of the optical system of the inspection apparatus are left and right symmetrical positions, the right and left reflected light intensities become uniform as shown in FIG. In addition, if the vertical position of the alignment light is displaced with respect to the optical axis of the eye to be examined, the reflected light from the cornea of the eye to be examined is displaced above or below the incident height position of the alignment light. It is possible to detect that the optical axis of the eye to be examined and the height position of the alignment light are displaced.

In this way, the left and right slit light projections are performed by projecting the alignment light from the left and right to the eye to be examined, detecting the reflected light reflected from the cornea of the eye to be examined, and controlling the movement of the control stage 80 based on the detection result. The focus positions of the optical systems 60a and 60b can be automatically matched with the center position of the cornea of the eye to be examined.
In the ophthalmic examination apparatus according to 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 examined, and then the Z direction of the optical system of the examination apparatus is aligned. Yes.

  In FIG. 12, 90 is an LED that emits red light or infrared light used as a light source of alignment light, 92 is a slit, and 94 is a half mirror. In this embodiment, the left and right slit light projection optical systems 60a and 60b are used to cause alignment light to enter the eye and the CCD camera 40 detects reflected light from the eye. 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. Note that the LED light source used as the alignment light source can be easily blinked at a predetermined frequency, which can improve the SN ratio of the detection signal and enable accurate alignment.

  FIG. 14 shows an example in which the alignment light optical system 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 positions symmetrical to the center line of the inspection apparatus with respect to the eye to be examined, and alignment light is projected from the respective alignment optical systems 95a and 95b to the eye to be examined from an oblique direction. Is configured to detect reflected light from the eye to be examined. 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. In the case of this 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 having 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 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 is configured to detect reflected light from the eye to be examined. In the case of this embodiment, alignment can be performed by matching the reflected light from the eye to be examined and the alignment light from the alignment optical system, and one alignment light source can be used. Reference numeral 98 denotes a beam splitter provided for detecting an image obtained by the imaging optical system (CCD camera) and an image obtained by the alignment optical system.

(Scan measurement)
In the scan measurement, from the state in which the focus position of the optical system of the inspection apparatus coincides with the apex position of the cornea of the eye to be examined, the optical system of the inspection apparatus is placed a predetermined distance (3.9 mm in this embodiment) on the back side of the eye to be examined. By scanning the optical system from the moved position (moving in the X direction), the 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 3.9 mm from the corneal apex of the eye to be examined. 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.
Depending on the measurement of the right eye or the left eye, 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. In the ophthalmic examination apparatus according to the present embodiment, the right eye or the left eye can be examined simply by selecting the left and right slit light projection optical systems 60a and 60b, so that the switching operation between the left and right eyes can be easily performed.
In addition, the ophthalmic 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 (pupil center) of the eye to be examined. It becomes possible to inspect in time.

(Measurement of central corneal thickness)
As shown in FIG. 16B, the thickness of the cornea at the center position of the eye to be inspected is slit light projection when the optical system of the inspection apparatus is matched with the center position of the cornea of the eye to be inspected using alignment light. Measurement can be performed by projecting slit light from the optical systems 60a and 60b and capturing an image at that time. Actually, the thickness of the cornea is converted from the data obtained from the image.
In the measurement of the central film thickness of the cornea, it is necessary to accurately detect the apex position of the cornea of the eye to be examined. However, in the ophthalmic examination apparatus according to the present embodiment, as described above, the apex position of the cornea is obtained using alignment light. Therefore, it is possible to obtain accurate inspection results without variations.

(Measurement of corneal curvature radius)
The radius of curvature of the cornea is measured from the state shown in FIG. 16B, that is, from the state where the apex position of the cornea of the eye to be inspected and the focus position of the optical system of the inspection apparatus coincide with each other (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 back side of the eye to be examined. FIG. 16A shows a state in which the optical system of the inspection apparatus is moved 3.9 mm from the vertex of the eye to be examined.
FIG. 17 shows an enlarged view of the state in which the slit light has moved to the back side by D from the apex position of the cornea with respect to the eye to be examined. In the figure, slit light 2 is slit light in a state in which the optical system of the inspection apparatus is moved. The slit light 2 is virtually extended, and an extension line up to intersect with the z-axis is a, in the z-axis direction. Is 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 curvature radius 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 (Dh / tan θ)
Note that the values of D, h, and θ are obtained by converting image data. In this way, the radius of curvature of the cornea can be obtained.

The thickness measurement of the central cornea and the measurement of the radius of curvature of the cornea described above can be performed in parallel with the scan measurement. By performing these measurements together with the scan measurement, the condition of the eye to be examined can be further improved. Can be detected accurately,
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 eye to be examined can be examined as quantitative data in a very clear shape, This makes it possible to easily detect ophthalmic diseases. In particular, it is not necessary to perform operations that can only be performed by specialists, such as using a lens for inspection, at the time of inspection. Therefore, it can be handled sufficiently by ordinary medical technicians and is suitable as an inspection device for ophthalmic diseases at the screening level. Can be used. In addition, since it does not place a burden on the subject for the examination and the examination time is short, the apparatus can be provided as an apparatus that can be easily examined.

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 explanatory drawing which shows the whole structure of one Embodiment of the ophthalmic test | inspection apparatus. It is explanatory drawing which shows the example of a screen display of the 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 with a wide-angle eye. It is explanatory drawing which shows the example of a screen display of the 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 in a narrow-angle eye, and the graph of the anterior chamber depth. It is explanatory drawing which shows the example of a screen display which displayed the cornea and the iris by a narrow-angle eye. It is a graph which shows the example of a measurement of anterior chamber depth. It is explanatory drawing which shows arrangement | positioning of the optical system in other embodiment of an ophthalmic examination apparatus. It is explanatory drawing which shows the planar arrangement | positioning of the optical system in other embodiment of an ophthalmic examination apparatus. It is explanatory drawing which shows the method to align with the vertex of the cornea of a to-be-tested eye. It is explanatory drawing which shows the other example of the alignment optical system of an ophthalmic examination apparatus. It is explanatory drawing which shows the further another example of the alignment optical system of an ophthalmic examination apparatus. It is explanatory drawing which shows the state which moves an optical system from the vertex position of a cornea. It is explanatory drawing which shows the method of measuring the curvature radius of a cornea.

Explanation of symbols

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 main body 56 Display 60a, 60b Slit light projection optical system 62 Halogen lamp 80 Control stage 95a, 95b Alignment optical system

Claims (4)

An ophthalmic examination apparatus for detecting an anterior chamber depth of an anterior segment of an eye to be examined and examining an ophthalmic disease of the eye to be examined,
A slit light projection optical system provided to project slit light from an oblique direction in which the projection angle is fixed with respect to the visual axis of the eye to be examined, toward the anterior eye portion of the eye to be examined;
A photographing optical system for photographing an anterior segment image obtained by the projection light projected by the slit light projection optical system;
The slit light projection optical system is moved so that the slit light projected from the slit light projection optical system is scanned from the pupil region to the periphery of the iris while maintaining the projection angle, and the slit light projection synchronously with the optical system, the imaging optical system, a moving mechanism for moving in parallel to the position directly facing the eye to the periphery of the iris together with the slit light projection optical system, for scanning,
When the moving mechanism scans slit light from the pupil area to the periphery of the iris and images the anterior segment by the imaging optical system, the image of the anterior segment is captured and stored every predetermined movement interval. Computer having image storage means, analysis means for analyzing the image recorded by the image storage means to obtain anterior chamber depth as quantitative measurement data, and display means for displaying the result of analysis by the analysis means And an ophthalmic examination apparatus. The slit light projection optical system is provided such that the projection position of the slit light can be set to the left side position and the right side position toward the subject according to whether the eye to be examined is the right eye or the left eye. The ophthalmic examination apparatus according to claim 1. The imaging optical system includes a microscope for viewing an enlarged cross-sectional image of the anterior segment of the eye, ophthalmic examination apparatus as claimed in claim 1, characterized in that it comprises a CCD camera for photographing 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 adjustment mechanism for finely adjusting the left and right position and height position of the optical system by operating the joystick, The ophthalmic examination apparatus according to any one of claims 1 to 3 .

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