JPH0910180A - Fundus examination device - Google Patents

Abstract

(57) [Summary] [Object] To provide a fundus examination apparatus capable of performing visible fluorescence imaging and infrared fluorescence imaging with a simple configuration that does not impose an extra burden on a subject and is easy to handle. A fundus illuminating means (3, 8a, 8b) for selectively irradiating the excitation illumination light for visible fluorescence imaging and the excitation illumination light for infrared fluorescence imaging to the fundus of the eye to be examined, and reflection of the excitation illumination light from the fundus. An image pickup unit (20) for picking up an image of the fundus of the eye to be inspected through a filter unit (18) having a transmission characteristic of blocking a light flux and transmitting both visible fluorescence and infrared fluorescence.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fundus examination apparatus such as a fundus camera used in an ophthalmology clinic.

[0002]

2. Description of the Related Art A conventional fundus examination apparatus capable of performing visible fluorescence imaging and infrared fluorescence imaging is disclosed in, for example, Japanese Patent Laid-Open No. 4-197337.
As described in, in the illumination optical system an exciter filter having a transmission characteristic of transmitting both the excitation illumination light for visible fluorescence imaging and the excitation illumination light for infrared fluorescence imaging, excited visible fluorescence and infrared light. It is known that a barrier filter having a transmission characteristic of transmitting both fluorescence is provided in an imaging system, and infrared fluorescence imaging or visible fluorescence imaging is performed by one camera, and further, those are configured to be performed at the same time. There is.

[0003]

However, in the case of Japanese Patent Laid-Open No. 4-197337, due to such a constitution, both the visible and infrared excitation illumination light are always radiated to the eye to be inspected. It puts an extra burden on the examiner. As a result, tearing and misalignment occur and the image quality deteriorates.

In order to avoid this, the exciter filter and the barrier filter are switched to those for visible fluorescence imaging and infrared fluorescence imaging respectively, and both must be exchanged each time imaging is switched, which is bothersome. It's complicated.

In view of the above-mentioned conventional example, the present invention provides a fundus examination apparatus capable of performing visible fluorescence imaging and infrared fluorescence imaging with a simple structure that does not impose an extra burden on a subject and is easy to handle. The purpose is to

[0006]

In order to achieve the above object, the fundus examination apparatus according to the first invention of the present application is
Excitation illumination light for visible fluorescence imaging and fundus illumination means for selectively irradiating excitation illumination light for infrared fluorescence imaging to the fundus of the eye to be inspected, blocking the reflected light flux from the fundus of the excitation illumination light, visible fluorescence, infrared An image pickup means for picking up an image of the fundus of the eye to be inspected through a filter means having a transmission characteristic of transmitting both fluorescence.
It is characterized by having.

In order to achieve the above object, the fundus examination apparatus according to the second aspect of the present invention selectively irradiates the fundus of the eye to be examined with the excitation illumination light for visible fluorescence imaging and the excitation illumination light for infrared fluorescence imaging. Fundus illuminating means to do, blocking the reflected light flux from the fundus of the excitation illumination light, visible fluorescence generated by the excitation illumination light, through the filter means having a transmission characteristic of transmitting both infrared fluorescence fundus eye to be examined And an observation system capable of observing the fundus of the eye to be inspected through a filter means for observation which has a transmission characteristic different from that of the filter means via an optical path branched from the image pickup system. It is characterized by

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of a fundus camera according to a first embodiment of the present invention.

In the drawing, 1 is a light source for observing a lamp or the like, alignment light source, 2 is a condenser lens, 3 is a light source for photographing a still image such as a strobe light source, 4 is a condenser lens, 5 is a mirror, and 6 is a ring-shaped opening. And 7 is a relay lens.

8a and 8b are FAG (fluoresc), respectively.
ent angiography), ICG (indocyanin green)
For exciter filters for visible fluorescence imaging and infrared fluorescence imaging, respectively.

9 is a relay lens, 10 is a perforated mirror,
11 is an objective lens, 12 is a movable lens for focusing, 1
Reference numeral 3 is a photographic lens, 14 is a flip-up mirror that retracts to the outside of the optical path at the moment of photography, 15 is a mirror, 16 is a field lens, and 17 is a lens.

Reference numeral 18 is a first barrier filter which is a bandpass filter for still image shooting, and 19 is a second barrier filter which is a bandpass filter for moving image observation.

Reference numeral 20 is a first camera such as a still video camera for photographing a still image, and 21 is a second camera such as a television camera for observing a moving image.

Reference numerals 22 and 23 are mode selection switches, 24 is an alignment monitor, 25 is a photographing switch, 26 is a control circuit, 27 is a reproduction monitor, E is an eye to be examined, and Ep.
Is the pupil of the eye to be inspected, and Er is the fundus of the eye to be inspected.

In this structure, the objective lens 11 to the first camera 20 constitutes a first photographing optical system, and the flip-up mirror 14 to the second camera 21 constitute a second photographing for observation. Configure an optical system.

A case of performing FAG photography (visible fluorescence photography) with this fundus camera will be described. First, the FAG mode is selected by the mode selection switch 22. Then, the FAG exciter filter 8a is inserted into the optical path.

Of the exciter filter 8a for FAG,
Spectral transmission characteristics are shown in FIGS. 2 and 3. 2 and 3, the vertical axis represents the transmittance T and the horizontal axis represents the light wavelength. The solid line indicated by 8a in FIGS. 2 and 3 is the spectral transmission characteristic of the exciter filter 8a. The solid line indicated by 8b is the spectral transmission characteristic of the ICG exciter filter 8b.

A light beam emitted from the light source 1 passes through a condenser lens 2, a strobe 3, and a condenser lens 4, and is reflected upward by a mirror 5, and a ring-shaped aperture of a diaphragm 6 conjugate to the anterior segment of the eye to be examined, a relay lens 7, After passing through the FAG exciter filter 8a and the relay lens 9, it is reflected to the left by the mirror part of the perforated mirror 10 that is conjugate to the anterior ocular segment of the subject's eye, passes through the objective lens 11, and illuminates the fundus Er from the subject's eye pupil Ep. To do.

The reflected light from the fundus thus illuminated is from the pupil Ep to the objective lens 11 and the perforated mirror 10.
Through the hole, the movable lens 12, and the taking lens 13, and is reflected upward by the flip-up mirror 14, and the mirror 1
The light is reflected to the right by 5 and passes through the field lens 16, the second barrier filter 19 for moving image observation, and the lens 17 to form an image on the imaging surface of the second camera 21 for moving image observation. This image is converted into a video signal and displayed on the monitor 24.

Second barrier filter 19 for moving image observation
The spectral transmission characteristics of are shown by broken lines 191 and 192 in FIG. As shown in this figure, this barrier filter 19 is
First transmission band 1 for transmitting visible fluorescence generated from the fundus after intravenous injection of a fluorescent agent when the exciter filter 8a for G is inserted
91, and a second transmission band 192 for transmitting infrared fluorescence generated from the fundus after the intravenous injection of the fluorescent agent when the exciter filter 8b for ICG is inserted. Further, as shown by A and B in FIG. 2, these transmission bands 191 and 192 are FA
It is set so as to have a characteristic of slightly transmitting even the excitation light itself transmitted through the exciter filters 8a and 8b for G and ICG.

Since a fluorescent image does not appear before the fluorescent agent is injected intravenously, in this state, of the reflection of the excitation light transmitted through the exciter filter 8a having the transmission band 8a in FIG. An image formed by only the light flux in the transmission band indicated by A (although most of the light is cut at 19) is displayed on the monitor 24.

The examiner checks the imaged region, alignment, and focus state by looking at this image. After confirming that these are good, the subject is intravenously injected with a fluorescent agent. When the fluorescent agent circulates to the fundus, a fluorescent image appears. This fluorescent image shows the first transmission band 1 of the second barrier filter 19.
Since the light passes through 91, a fluorescence image is displayed on the monitor 24 by being superimposed on the infrared fundus image.

After confirming the appearance of the fluorescent image in this manner, the examiner operates the photographing switch 28. As a result, the flip-up mirror 14 is retracted out of the optical path and the strobe light source 3 emits light. The light flux emitted from the strobe light source 3 passes through the same optical path as the light emitted from the light source 1, and illuminates the fundus with light having a wavelength in the transmission band of the exciter filter 8a.
Fluorescence emitted from the fundus illuminated in this way is reflected by the pupil Ep.
Then, an image is formed on the imaging surface of the first camera 20 for still image shooting through the objective lens 8, the hole of the perforated mirror 10, the movable lens 12, the taking lens 13, and the first barrier filter 18.

Spectral transmission characteristics of the first barrier filter 18a are shown by broken lines 181 and 182 in FIG. in this way,
This barrier filter 18a is an F shown by 8a in FIG.
Since the excitation light transmitted through the AG exciter filter 8a is blocked and only the fluorescence generated from the fundus by the excitation light transmitted through the FAG exciter filter 8a is transmitted, a fluorescence image is formed on the imaging surface of the first camera 20. Only the image is formed.

This image is converted into an electric signal and then converted into a digital signal, which is stored in the memory in the control circuit 26 and simultaneously displayed on the immediate reproduction monitor 27. The examiner repeats the above-described operation to end the FAG imaging.

Next, infrared fluorescence imaging (ICG imaging) will be described. First, by using the mode selection switch 23, the IC
Select G mode. Then, the ICG exciter filter 8b is inserted in the optical path.

In such an arrangement, as in the case of FAG photography, the luminous flux emitted from the light source 1 passes through the condenser lens 2, strobe 3, condenser lens 4, is reflected upward by the mirror 5, and has a ring shape of the diaphragm 6. Via the relay lens 7. Then, this time, it passes through the exciter filter 8b for ICG, passes through the relay lens 9, is reflected to the left by the mirror portion of the perforated mirror 10, passes through the objective lens, and illuminates the fundus Er from the eye Ep to be examined.

The fundus image illuminated in this way is the pupil Ep.
Through the objective lens 11, the hole portion of the perforated mirror 10, the movable lens 12, and the taking lens 13, the light is reflected upward by the first flip-up mirror 14, further reflected by the mirror 15 to the right, and the field lens 16 An image is formed on the imaging surface of the second camera 21 for moving image observation, passing through the barrier filter 19 for moving image observation and the lens 17. This image is
It is converted into a video signal and displayed on the monitor 24.

In FIG. 2, the transmission band of the ICG exciter filter 8b is indicated by the solid line 8b as described above. Also, the spectral transmission characteristics of the barrier filter 19 for moving image observation are shown by the transmission bands by broken lines 191 and 192. As indicated by B in this figure, these filters have a common transmission band. Therefore, as in the case of FAG imaging, a fundus image is formed on the imaging surface of the camera 21 by the light in the common transmission band before the intravenous injection of the fluorescent agent in which the fluorescent image does not appear.

The examiner looks at this image displayed on the monitor 24 and confirms the photographing region, alignment, and focus state.
After confirming that these are good, a fluorescent agent (indocyanine green) is intravenously injected into the subject.

When the fluorescent agent circulates to the fundus, a fluorescent image appears. Since this fluorescent image passes through the second transmission band 192 of the barrier filter 19, the fluorescent image is displayed on the monitor 24 so as to be superimposed on the infrared fundus image.

After confirming the appearance of the fluorescent image in this manner, the examiner operates the photographing switch 28. As a result, the flip-up mirror 14 retracts to the outside of the optical path and the strobe light source 3 emits light. The light flux emitted from the strobe light source 3 illuminates the fundus through the same optical path as the light emitted from the light source 1. The fundus image illuminated in this way is viewed from the pupil Ep through the objective lens 8, the hole portion of the perforated mirror 10, the movable lens 1.
2. The light passes through the photographing lens 13 and the barrier filter 18 having the transmission band 182 that transmits the fluorescence wavelength, and forms an image on the image pickup surface of the first camera 20 for still image photographing.

As shown in FIG. 3, since the barrier filter 18 does not transmit the reflected light of the excitation light but only the fluorescence, only the fluorescent image is formed on the image pickup surface.

This image is converted into an electric signal and then converted into a digital signal, which is stored in the memory in the control circuit 26 and simultaneously displayed on the immediate reproduction monitor 27. The examiner repeats the above-described operation to end the ICG imaging.

The reflection image and the fluorescence image have completely different intensities with respect to the same illumination light. Therefore, in order to observe the reflection image and the fluorescence image at the same time, the reflection image is reflected as shown in FIGS. The wavelength transmission regions of the exciter filter and the barrier filter are set so that only a part of the image is taken out, and the reflection image and the fluorescence image are of the same degree or the fluorescence image is a little stronger. With this setting, it is easy to observe both.

In the above-described embodiment, a moving image is observed by using a part of the reflected light of the excitation light for visible fluorescence during the FAG photographing, and a part of the reflected light of the excitation light for the infrared fluorescence is observed during the ICG photographing. Although the moving image observation was performed using the above, the exciter filter may be provided with a transmission wavelength band for moving image observation, and the observation light may be used to perform the observation alignment.

[0037]

As described above, the first embodiment according to the present application is described.
According to the invention: Since a dual-band barrier filter that is common to both infrared fluorescence imaging and visible fluorescence imaging can be used, it is not necessary to provide a barrier filter switching mechanism, and the structure is simplified. While the switching operation can be simplified, 1. By switching the exciter filter between FAG imaging and ICG imaging, it is possible to reduce the light illuminating the subject compared to the case where a dual band exciter filter is used. Since it is possible to prevent the user from feeling glare, it is possible to reduce the feeling of tearing and to maintain good alignment, thereby further improving the image quality.

Further, according to the second invention of the present application, the fundus of the eye to be inspected can be observed through the observing filter means having a transmission characteristic different from that of the photographic filter means. In addition to the exciter filter and barrier filter suitable for such shooting, the optimum filter settings can be set on the video viewing side.

[Brief description of the drawings]

FIG. 1 is a diagram showing an arrangement according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a spectral characteristic of a filter.

FIG. 3 is a diagram showing a spectral characteristic of a filter.

[Explanation of symbols]

 1 Light source for observation 2 Condenser lens 3 Light source for still image shooting 4 Condenser lens 5 Mirror 6 Ring aperture stop 7 Relay lens 8a Exciter filter for FAG shooting 8b Exciter filter for ICG shooting 9 Relay lens 10 Perforated mirror 11 Objective lens 12 movable lens 13 shooting lens 14 flip-up mirror 15 mirror 16 field lens 17 lens 18 first barrier filter for still image shooting 19 second barrier filter for video observation 20 first camera for still image shooting 21 video Second camera for observation 22,23 Mode selection switch 24 Alignment monitor 25 Shooting switch 26 Control circuit 27 Playback monitor

Claims (2)

[Claims] 1. A fundus illuminating means for selectively irradiating the excitation illumination light for visible fluorescence photography and the excitation illumination light for infrared fluorescence photography to the fundus of the eye to be inspected, and blocking the reflected light flux from the fundus of the excitation illumination light, A fundus examination apparatus comprising: an image pickup unit that takes an image of a fundus of an eye to be inspected through a filter unit having a transmission characteristic that transmits both visible fluorescence and infrared fluorescence generated by the excitation illumination light. 2. A fundus illuminating means for selectively irradiating the excitation illumination light for visible fluorescence photography and the excitation illumination light for infrared fluorescence photography to the fundus of the eye to be inspected, and blocking the reflected light flux from the fundus of the excitation illumination light, An imaging system that causes the imaging means to image the fundus of the eye to be inspected through a filter means having a transmission characteristic of transmitting both visible fluorescence generated by the excitation illumination light and infrared fluorescence.
A fundus examination apparatus comprising an observation system capable of observing a fundus of an eye to be inspected through a filter means for observation having a transmission characteristic different from that of the filter means via an optical path branched from the imaging system.