JPH0716481B2 - Corneal endothelial cell observation and imaging device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for observing corneal endothelial cells, and more particularly, a device for observing and photographing corneal endothelial cells of an eye to be examined by illuminating the cornea of the subject's eye with illumination light. It relates to the device.

[0002]

2. Description of the Related Art Conventionally, as a corneal endothelial cell observing and photographing apparatus for observing and photographing a corneal endothelial cell image of an eye to be inspected, a cone is formed on the corneal surface of the eye to be inspected after anesthetizing the eye of the subject (patient). A contact type in which a lens is contacted to observe and photograph a corneal endothelium image is known. In this contact type,
There is a problem of damaging the corneal surface. In addition, it takes time and effort to disinfect the cone lens. Therefore, a non-contact type in which an optical attachment for observing corneal endothelium is attached to a slit lamp to observe and photograph a corneal endothelial cell image has been developed.

In this non-contact type corneal endothelial cell observing / photographing device, the relative positional relationship between the eye to be inspected and the optical system of the device is roughly adjusted by visual observation, and then the illumination light from the illumination light source for observation is directed to the cornea. It is known that oblique irradiation is performed and corneal endothelium cells are focused through an eyepiece lens based on the reflected light flux from the cornea. It is also known to focus on the corneal endothelial cells displayed on the monitor.

[0004]

By the way, since the cornea is thin, it must be observed at a high magnification in order to observe corneal endothelial cells. Further, the eye to be inspected constantly undergoes involuntary eye movements, but since the magnification is high, the corneal endothelial cell image is greatly shaken by the involuntary eye movements. Therefore, the non-contact type requires considerable skill to observe and photograph the corneal endothelial cells.

When photographing a corneal endothelial cell image, the photographing switch must be operated at the same time as focusing.
It requires considerable skill to operate the photographing switch at the same time as focusing of corneal endothelial cells.

Further, in the alignment operation of the main body of the apparatus with respect to the cornea, the proper absolute positional relationship between the eye to be inspected and the optical system of the apparatus has not been determined, and the corneal endothelial cell image itself or the reflection from the corneal surface appearing beside it. Since you will be observing a completely dark state where you cannot see anything until you search for the luminous flux, it depends greatly on the intuition and experience of the examiner.

Moreover, since alignment often takes a long time, the subject is forced to keep his eyes open for a long time until the subject is focused and the photographing is completed, which causes great pain to the subject. .

The present invention has been made in view of the above circumstances, and it becomes possible to roughly position corneal endothelial cells while observing the anterior segment of the eye to be examined, and the examiner can obtain the examination time without any skill. It is an object of the present invention to provide a corneal endothelial cell observation and imaging device that can be shortened and thus can reduce the burden on the examiner and the subject.

[0009]

In order to achieve the object, the invention according to claim 1 is to provide an illumination optical system for irradiating the cornea of an eye to be inspected with illumination light, and a luminous flux reflected from the cornea. The gist of the present invention is to include an observation and photographing optical system capable of observing and photographing as an image in a non-contact state with the cornea, and an anterior segment observation optical system for observing the anterior segment of the eye.

[0010]

In the structure according to the first aspect, the alignment of the device optical system with respect to the eye to be examined is adjusted while observing the anterior eye portion of the eye to be examined using the anterior segment observation optical system. Next, the illumination optical system irradiates the cornea of the subject's eye with illumination light. Then, the observation / photographing optical system observes / photographs the reflection image from the cornea.

[0011]

EXAMPLE An example of a corneal endothelial cell observation and photographing device of the present invention will be described below with reference to FIGS.

FIG. 1 is a plan view showing a device optical system of the corneal endothelial cell observation and photographing device. In FIG. 1, reference numeral 1 is an anterior segment observation optical system for observing an anterior segment of an eye E to be examined.

The anterior segment observation optical system 1 includes a half mirror 2,
The objective lens 3, the half mirror 4, the optical path switching mirror 5, and the CCD 6 are generally included, and O1 is an optical axis thereof. The anterior segment of the eye E is illuminated by the anterior segment illumination light source 7. The half mirror 2 constitutes a part of the alignment optical system 8 as an alignment index light projection means.

As shown in FIG. 2, the alignment optical system 8 has an alignment light source 9, a pinhole plate 10, a projection lens 11, a diaphragm 12, and a half mirror 13. The pinhole plate 10 is disposed at the focal point of the projection lens 11, and the alignment index light that has passed through the pinhole plate 10 is collimated by the projection lens 11 and guided to the half mirror 2 via the half mirror 13. The parallel light flux is reflected by the half mirror 2 and guided to the cornea C. The half mirror 13 constitutes a part of the fixation target projection optical system 14.

The fixation target projection optical system 14 comprises a left-eye projection system 15 and a right-eye projection system 16, as shown in FIG.

The left-eye projection system 15 and the right-eye projection system 16
In the right eye, the eyeball optical axis O2 and the visual axis S1 of the eye E are inclined 5 ° to the right while the right eye is provided to the left. This is because in the eye, as shown in FIG. 3C, the eyeball optical axis O2 and the visual axis S1 are inclined to the left by 5 °. The left-eye projection system 15 and the right-eye projection system 16 respectively include a fixation target light source 17 and a pinhole plate 1.
8. Optical member 1 for presenting a plurality of fixation target light sources 17
9 has a projection lens 20.

The fixation target light source 17 is linked to the movement of the apparatus main body H, which will be described later, so that the right eye one is automatically turned on during the right eye examination and the left eye one is automatically turned on during the left eye examination. Lights up. The fixation target light from the fixation target projection optical system 14 is transmitted through the half mirror 13 and the half mirror 2 to the eye E to be examined.
Be led to. At that time, the fixation target light is reflected by the reflecting surfaces 19a and 19b of the optical member 19 a plurality of times,
A plurality of fixation target light source images are presented to the eye E to be examined. The subject fixes the fixation target light source image according to the diopter, and the alignment adjustment is performed while fixing the fixation target light source image.

The alignment light beam K is reflected by the surface T of the cornea C as shown in FIG. The alignment light flux K is reflected by the surface T so as to form a bright spot image R at an intermediate position between the corneal vertex P and the corneal curvature center O3. The reflected light flux is guided to the objective lens 3 via the half mirror 2.

A part of the reflected light flux guided to the objective lens 3 is reflected by the half mirror 4, and the rest of the light flux passes through the half mirror 4. The reflected light flux reflected by the half mirror 4 is guided to an alignment detection sensor 4'as a light receiving means. Alignment detection sensor 4 '
For example, a position sensor (PSD) is used for this, and the details of the function will be described later.

The optical path switching mirror 5 is normally retracted from the optical path of the anterior segment observation optical system 1. The optical path switching mirror 5 has a light shielding surface 5a on one surface and a total reflection surface 5b on the other surface. The light flux that has passed through the half mirror 4 is guided to the CCD 6 to form an image, and a bright spot image is formed on the CCD 6. The half mirror 4 reflects the light flux from the alignment pattern projection optical system 21.

The alignment pattern projection optical system 21 includes
The outline includes a light source 22 for alignment pattern, an alignment pattern plate 23, and a projection lens 24.

An annular pattern is formed on the alignment pattern plate 23. The pattern forming light flux forming the annular pattern is reflected by the half mirror 4 and C
It is guided to the CD 6 and an annular pattern image is formed on the CCD 6.

The CCD 6 is connected to a monitor device (not shown), and an anterior ocular segment image 26 of the eye E is displayed on the screen 25 of the monitor device as shown in FIG. Further, an annular pattern image 27 is displayed. Alignment adjustment is performed by swinging the apparatus main body H up and down (Y direction) and left and right (X direction) so that the light flux that is reflected by the cornea C and forms the bright spot image R ′ is located at the center of the annular pattern image 27. Then, the eyeball optical axis O2 of the eye E and the apparatus optical axis O1 are matched. In addition, the working distance is set by shifting the device body H forward and backward with respect to the eye E (in the Z direction).

An illumination optical system 28 and an observation / photographing optical system 29 are provided on both sides of the anterior segment observation optical system 1. The illumination optical system 28 irradiates the cornea C of the eye E with an illumination light beam from an oblique direction.

The illumination optical system 28 is an illumination light source 3 for observation.
0, a condenser lens 31, an infrared filter 31 ′, an illumination light source 32 for photographing, a condenser lens 33, a slit plate 34, and a light projecting lens 35. The illumination light source 30 and the illumination light source 32 are conjugate with respect to the condenser lens 31.

A halogen lamp is used as the illumination light source 30, and a xenon lamp is used as the illumination light source 32. The light flux emitted from the illumination light source 30 passes through the condenser lens 31 and the infrared filter 31 ′ and is once converged at the position where the illumination light source 32 is arranged. The infrared light flux is guided to the condenser lens 33 as if emitted from the illumination light source 32. The infrared light flux condensed by the condenser lens 33 is formed by the slit plate 3
Guided to 4. An elongated rectangular slit 36 is formed in the slit plate 34. The infrared light flux passes through the slit 36 and is guided to the light projecting lens 35.

Reference numeral 35 'is an optical member for correcting the optical path length.
FIG. 1 shows a state of being inserted into the optical path when observing endothelial cells.
It is made up of a convex lens because it retracts and corrects the optical path length when photographing with visible light. On the contrary, when the optical member 35 'is not inserted into the optical path during observation but is to be inserted during photographing, a plane parallel plate or a concave lens may be used. The insertion position of the optical member 35 'is outside the position shown in the figure, and the projection lens 3
It is also conceivable to provide it between 5 and the cornea C. When the alignment is completed, the slit plate 34 and the cornea C are substantially conjugate with respect to the light projecting lens 35, and the cornea C is irradiated with the slit light flux. This slit light flux traverses the cornea C from its surface T toward the inside.

The light source section comprising the illumination light source 30, the condenser lens 31, the infrared filter 31 ', the illumination light source 32, and the condenser lens 33 may be arranged as shown in FIG. In FIG. 6, 37 is a dichroic mirror, and 38 and 39.
Is a concave reflector. The dichroic mirror 37 is arranged between the condenser lens 31 and the slit plate 34, transmits infrared light, and reflects visible light.

The observation / photographing optical system 29 is roughly composed of an objective lens 40, a half mirror 41, a mask 42, a relay lens 43, a mirror 44, a variable power lens 45, a focusing lens 46, and an optical path switching mirror 5.

The optical path switching mirror 5 is an anterior ocular segment observation optical system 1 based on the detection output of the alignment detection sensor 4 '.
Automatically inserted in the optical path of. When the alignment is completed, the mask 42 and the cornea C are substantially conjugate with respect to the objective lens 40.

The slit light beam is scattered and reflected by the cornea C. The state of the scattering reflection is shown in FIG. Part of the slit light beam is first reflected on the corneal surface T which is the boundary surface between the air and the cornea C. The light quantity of the scattered reflected light flux L from the corneal surface T is the largest. The light quantity of the scattered reflected light flux M from the corneal endothelial cell N is relatively small. The light amount of the reflected light flux L ′ from the corneal substance M ′ is the smallest. The scattered reflected light flux M is condensed by the objective lens 40, is guided to the half mirror 41 through the optical path length correction member 40 ′.

As shown in FIG. 1, the optical path length correcting member 40 'is inserted into the optical path during observation with infrared illumination light and retracted from the optical path during photographing with visible light. At this time, a convex lens is used as the optical path length correction member 40 '. On the contrary, a plane-parallel plate or a concave lens is inserted into the optical path as an optical path length correcting member 40 'during photographing to form a corneal endothelial cell image at the reference position, and the optical path correcting member 40' is used during observation. It is also possible to evacuate from. An optical path length correcting member 43 ', which will be described later, also has the same movement and shape as the optical path length correcting member 40', and its insertion position is at the position shown in FIG. 1 and in front of the objective lens 40 (on the side of the cornea C). ), Between the half mirror 41 and the mask 42, and between the focusing lens 46 and the optical path switching mirror 5, the same effect can be obtained.

A part of the scattered and reflected light flux is reflected by the half mirror 41 and guided to the line sensor 47 as a focus state detection sensor. Further, the scattered reflected light flux that has passed through the half mirror 41 is guided to the mask 42, and a corneal cross-sectional image including the corneal endothelial cells N is formed at the arrangement position of the mask 42.

The mask 42 plays a role of blocking an extra reflected light beam except for forming a corneal endothelial cell image. The scattered and reflected light flux forming the corneal endothelial cell image is transmitted by the optical path length correction member 4
3 ', relay lens 43, mirror 44, variable magnification lens 4
5. After being guided to the optical path switching mirror 5 through the focusing lens 46 and reflected by the optical path switching mirror 5, CC
An image is formed on D6. A corneal endothelial cell image 48 is displayed on the screen 25 as shown in FIG. In FIG. 8, 4
Reference numeral 9 is an optical image formed by the reflected light flux from the corneal surface T if it is not shielded by the mask 42, and 50 is an optical image by the scattered reflected light flux from the corneal substance M ′.

The line sensor 47 is arranged in the direction of the cross section of the cornea C as shown in FIG. 9B, and the intensity distribution of the scattered reflected light flux is as shown in FIG. 9A. In FIG. 9A, the symbol U is a peak due to the scattered reflected light flux scattered and reflected on the surface T of the cornea C.
The symbol V is the peak of the endothelial cell portion of the cornea C. The peak U corresponds to the optical image 49, and the peak V corresponds to the optical image 48.

The output of the element at each address of the line sensor 47 is input to the focus determination circuit 47 ', as shown in FIG. As shown in FIG. 9A, the focus determination circuit 47 'determines the address of the peak V by storing all signals including the peak U and the peak V and performing arithmetic processing. Then, the focus determination circuit 47 'determines whether or not the address L of the peak V coincides with the central address Q of the line sensor 47.

When the apparatus main body H is moved toward and away from the anterior ocular segment of the eye E (the optical system of the apparatus is moved in the Z direction), the address L of the peak V is moved. The device body H is designed so that the corneal endothelial cells are focused when the address L of the peak V coincides with the central address Q. When the address L of the peak V matches the center address Q, the focus determination circuit 47 'outputs a shooting signal to the shooting light source light emission control circuit 32',
As a result, the illumination light source 32 emits light, the eye E to be inspected is illuminated, and photographing is automatically performed.

As shown in FIG. 10, the line sensor 47 is arranged in the direction orthogonal to the thickness of the cornea C, and the pixel size of the line sensor 47 is made smaller than that shown in FIG. When the detection output W based on the contrast of the image 48 is equal to or higher than a predetermined level V1 as shown in FIG.
8 may be photographed.

The anterior ocular segment observation optical system 1, the illumination optical system 28, and the observation / photographing optical system 29 are housed in an apparatus body case 52 as shown in FIG.

In FIG. 12, reference numeral 53 is a base having a built-in power source. A pedestal 54 is provided above the base 53 so as to be movable back and forth and left and right by operating a control lever 54a. The control lever 54a is provided with a photographing switch 54b, which is used in the manual photographing mode. A motor 55 and a pillar 56 are provided on the top of the gantry 54.

The motor 55 and the support 56 are connected to a pinion rack (not shown), and the support 56 is moved up and down by the motor 55. A table 57 is provided at the upper end of the pillar 56.

A column 58 and a motor 59 are provided on the table 57. A table 60 is slidably provided on the upper ends of the columns 58. A rack 61 is provided at the rear end of the table 60, as shown in FIG. A pinion 62 is provided on the output shaft of the motor 59, and the pinion 62 is meshed with the rack 61. Further, a motor 63 and a support column 64 are provided above the table 60. A pinion 65 is provided on the output shaft of the motor 63. The device main body case 52 is slidably provided on the upper part of the support column 64. A rack 66 is provided on the side of the apparatus body case 52. Rack 66 is pinion 65
Is meshed with. In FIG. 13, 6'denotes a signal processing unit.

The motor 55 is a device body H for the eye E to be inspected.
Motor 59 is used to automatically perform alignment in the Y direction of the device, the motor 59 is used to automatically perform alignment of the device body H with respect to the eye E in the X direction, and the motor 63 is used with the motor 63. Are used to automatically perform the alignment in the Z direction, and these can be operated in the automatic photographing mode. That is, the motors 55, 5
Reference numerals 9 and 63 constitute drive means for driving the apparatus main body H based on the light receiving output of the light receiving means.

In this automatic photographing mode, the control lever 54a is operated while observing the anterior segment image 26 displayed on the screen 25 by the anterior segment observation optical system 1 to operate the bright spot image R '.
Can be clearly seen, and the gantry 54 is roughly operated so that the bright spot image R ′ approaches the predetermined annular circle 27. As a result, the scattered and reflected light flux forming the bright spot image R ′ is guided to the alignment detection sensor 4 ′.

The alignment detection sensor 4'detects the X-direction position information and the Y-direction position information of the bright spot image R '. The X-direction position information and the Y-direction position information are input to the XY alignment detection circuit 67 as shown in FIG.

When the X-direction alignment and the Y-direction alignment are completed, the XY alignment detection circuit 67 outputs an alignment completion signal to the mirror drive circuit 68. The optical path switching mirror 5 is inserted into the optical path of the anterior segment observation optical system 1 by the mirror drive circuit 68.

Further, the X of the alignment detection sensor 4 '
The direction position information and the Y direction position information are input to an alignment determination circuit (not shown). This alignment determination circuit uses a motor 59 so that the optical axis O1 of the device optical system approaches the optical axis O2 of the eye E from the X direction based on the X direction position information.
And the motor 55 is driven so that the optical axis O1 of the apparatus optical system approaches the optical axis O2 of the eye E from the Y direction based on the Y direction position information.

The table 60 is slid in the X direction by the motor 59, the table 57 is moved in the Y direction by the motor 55, and the optical axis O1 of the optical system of the apparatus and the eye E to be inspected automatically based on the alignment detection sensor 4 '. Is aligned with the optical axis O2.

On the other hand, the motor 63 moves the apparatus main body case 52 in the Z direction so that the address L of the peak V detected by the one-dimensional line sensor 47 and the central address Q coincide with each other. As a result, the alignment of the optical system of the device with respect to the eye E is automatically completed, and the corneal endothelial cells N are photographed.

FIG. 15 shows another embodiment of the apparatus for observing and observing corneal endothelial cells according to the present invention, in which a dichroic mirror 69 is used instead of the optical path switching mirror 5. At this time, infrared light sources are used as the illumination light sources 7, 7 for observing the anterior segment shown in FIG. 1, the alignment index light and the pattern forming light flux are infrared light, and the alignment index reflected by the cornea C is used. The light flux and the reflected light flux reflected by the anterior segment are transmitted, and the slit light flux reflected by the cornea C is reflected. On the screen 25, the screen is switched from the anterior segment image 26 to the corneal endothelial cell image 48 by turning off the illumination light source 7, the alignment light source 9, and the alignment pattern light source 22. Further, while one optical path is being used, the other optical path, for example, the dichroic mirror 69
It is also effective to insert a shutter (not shown) immediately before.

As described above, in the corneal endothelial cell observing / photographing apparatus of the present invention, the adjustment of the first step by the conventional visual measurement is more accurate while observing the anterior segment of the eye to be inspected with the monitor (not shown). Therefore, the corneal endothelial cells in the second stage can be easily and quickly found.

Since the illumination optical system and the observation / photographing optical system are arranged with the optical axis of the eyeball of the subject's eye as a boundary, the operation for aligning the eyeball of the subject's eye can be facilitated. It can be carried out.

Further, since the image receiving element for the anterior segment image guided to the anterior segment observation optical system and the image receiving element for the corneal endothelial cell image guided to the observation and photographing optical system are shared, it is expensive. Only one image receiving element is required.

Moreover, since the observation illumination light provided in the illumination optical system is infrared light, it is possible to reduce the pain to the subject.

[0055]

Since the apparatus for observing and observing corneal endothelial cells according to the present invention is configured as described above, the corneal endothelial cells can be roughly positioned while observing the anterior segment of the eye to be inspected. The inspection time can be shortened without requiring skill, and thus the burden on the examiner and the examinee can be reduced.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an optical system showing an embodiment of a corneal endothelial cell observation and imaging device according to the present invention.

FIG. 2 is a diagram showing an alignment optical system according to the present invention.

FIG. 3 is a diagram showing a fixation target projection optical system according to the present invention.

FIG. 4 is a diagram showing a reflection state of an alignment index light beam according to the present invention.

FIG. 5 is a diagram showing a display state of an anterior segment image.

FIG. 6 is a diagram showing another example of the light source section of the illumination optical system according to the present invention.

FIG. 7 is a diagram showing a reflection state of a slit light beam on the cornea.

FIG. 8 is a diagram showing a reflective state of a corneal endothelial cell image.

FIG. 9 is a diagram showing a relationship between a corneal endothelial cell image and the amount of light received by a line sensor.

FIG. 10 is a diagram showing an arrangement state of line sensors for a corneal endothelial cell image.

11 is a diagram showing an output state from the line sensor shown in FIG.

FIG. 12 is a side view showing the overall configuration of a corneal endothelial cell observation and imaging device according to the present invention.

FIG. 13 is a plan view partially showing the corneal endothelial cell observation and photographing device according to the present invention.

FIG. 14 is a diagram showing a drive circuit of an optical path switching mirror according to the present invention.

15 is a diagram showing an example in which a dichroic mirror is used instead of the optical path switching mirror shown in FIG.

[Explanation of symbols]

 E ... Eye to be inspected C ... Corneal 1 ... Anterior ocular segment observation optical system 28 ... Illumination optical system 29 ... Observation and photographing optical system 30 ... Observation illumination light source (halogen lamp) 32 ... Imaging illumination light source (xenon lamp)

Claims (4)

[Claims] 1. An illumination optical system that obliquely illuminates the cornea of an eye to be inspected, and an observation and photographing optical system that receives and observes and photographs a reflection image from the cornea including corneal endothelial cells, An anterior ocular segment observation optical system for observing the anterior ocular segment of the subject's eye. 2. The corneal endothelium cell according to claim 1, wherein the illumination optical system and the observation and photography optical system are arranged substantially symmetrically with respect to an optical axis of the eyeball of the eye to be examined. Observation and photography device. 3. The anterior ocular segment observation optical system has an image receiving element for receiving an anterior ocular segment image of the subject's eye, and the image receiving element is also used as an image receiving element for receiving a reflected image from the cornea. The device for observing and observing corneal endothelial cells according to claim 1, wherein 4. The illuminating light for observation of the illuminating optical system is infrared light, and when the wavelength of the illuminating light for observation is different from that of the illuminating optical system, an optical path length correction is performed in the middle of the illuminating optical system and the observing / photographing optical system. The corneal endothelial cell observation and photographing device according to claim 1, wherein an optical member for taking in and out is taken in and out according to observation and photographing.