JPH11225972A - Fundus camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fundus camera capable of performing alignment and focusing even if it is in a latter period of infrared fluorescent photographing. SOLUTION: At the time of infrared fluorescent photographing, an exciter filter F1 is inserted into an illumination optical system, a barrier filter F3 is inserted into a focusing optical system, and an eyeground infrared fluorescent image is recorded in a moving picture recorder 27 through a black and white camera 26. Since an eyeground image becomes dark in a latter period of infrared fluorescent photographing, it is changed over to a stationary picture recording by means of an electronic flash SR. A barrier filter F2 for alignment is inserted instead of the barrier filter F3 at the time of alignment before it, and the barrier filter F3 is inserted into an optical path again after alignment is completed for photographing. Since the barrier filter F2 for alignment is used at the time of alignment in this configuration, the observation of eyeground image becomes possible and alignment and focusing become easy, even if it is in a latter period of infrared fluorescent photographing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fundus camera, and more particularly, to irradiates light from an observation light source to the fundus of an eye to be examined through an illumination system, and reflects light reflected from the fundus through an imaging optical system. The present invention relates to a fundus camera capable of performing fluorescent imaging for forming an image and observing the fundus.

[0002]

2. Description of the Related Art In general, when performing infrared fluorescence photographing with this kind of fundus camera, observation is performed by a black-and-white camera having high sensitivity to infrared rays, which is directly recorded as it is as a continuous video (moving image) directly on a VTR. Recording is performed as still video (still image) by flash photography using a flash or a strobe. In addition, in infrared fluorescence imaging, alignment and focusing are performed while looking at a fundus image projected on a monitor.

[0003]

However, when the infrared fluorescent photographing is started, both the exciter filter and the barrier filter are inserted, and only the infrared fluorescent light is observed. This infrared fluorescent light is very weak (about one-fifth of visible fluorescent imaging), and the fluorescent agent is metabolized in the latter stage of infrared fluorescent imaging. Becomes very difficult. Although the light amount of the observation light source may be increased, the brightness of the lamp is limited and difficult. Therefore, in the latter period when the fundus image is dark, an image is often recorded by flash photography using a strobe, which can provide a high luminance particularly instantaneously. However, the photographing itself can be performed by the strobe light, and there is no problem. However, it remains dark at the time of alignment. For this reason, there is a problem that alignment is difficult and focusing is difficult, and operability is extremely deteriorated.

Accordingly, an object of the present invention is to provide a fundus camera which eliminates the above-mentioned drawbacks of the conventional example and which can easily perform alignment and focusing even in a later stage of infrared fluorescence imaging.

[0005]

In order to solve this problem, the present invention irradiates light from an observation light source to the fundus of an eye to be inspected via an illumination system, and converts reflected light from the fundus into an image forming optical system. In a fundus camera capable of performing fluorescence imaging for forming an image through a system and observing the fundus, an exciter filter for infrared fluorescence imaging that can be inserted into and removed from the illumination system, and that can be inserted into and removed from the imaging optical system A first barrier filter for infrared fluorescence imaging alignment; and a second barrier filter for infrared fluorescence imaging that can be replaced with the first barrier filter. A configuration was adopted in which a filter was inserted and the second barrier filter was inserted into the optical path during infrared fluorescence imaging.

According to such a configuration, a barrier filter for alignment is used at the time of alignment at the latter stage of infrared fluorescence imaging, so that the fundus image can be observed even at the latter stage of infrared fluorescence imaging. Alignment and focusing are facilitated.

The transmission band of the first barrier filter is the second
On the shorter wavelength side than the transmission band of the barrier filter, for example, the exciter filter transmits a wavelength of 700 to 815 nm, the first barrier filter cuts a wavelength of 780 nm or less and transmits a wavelength of 780 nm or more,
The second barrier filter cuts a wavelength of 815 nm or less and transmits a wavelength of 815 nm or more.

In such a configuration, the first barrier filter having a transmission band on the shorter wavelength side than the second barrier filter is inserted into the optical path during alignment during infrared fluorescence imaging, so that it crosses the exciter filter. A band is formed, and the fundus reflected light from a place where there is no fluorescent agent can pass through the barrier filter to some extent, and emits pseudo-fluorescence. Therefore, even in the latter stage of the infrared fluorescence imaging, the observation of the fundus image becomes possible, and alignment and focusing can be easily performed. After performing alignment and focusing, the examiner can replace the barrier filter with the second barrier filter and perform flash photography with a strobe.

As described above, a fundus camera capable of performing infrared fluorescence imaging, which can easily perform alignment and focusing even in the latter stage of infrared fluorescence imaging, is provided.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings.

FIG. 1 shows a fundus camera according to the present invention.
A lamp LA as an observation light source is disposed at the center of the mirror M1, and light emitted from the lamp LA passes through a condenser lens 1, a strobe SR as an imaging light source, a condenser lens 2, a filter F1, and then a total reflection mirror. M
2, a lens 3, a ring slit 4 for forming a ring-shaped illumination, a relay lens 5, a black dot plate 6 for reflecting an objective lens, a relay lens 7, a hole with a hole in the center. After being reflected by the aperture total reflection mirror M3, it passes through the objective lens 8 and then enters the fundus Er from the pupil Ep of the eye E to be examined. Note that the filter F1 is an exciter filter for infrared fluorescence photography, and is 700 to 815.
It transmits at a wavelength of nm and is inserted into the optical path only during infrared fluorescence imaging, and is removed from the optical path during normal fundus imaging.

The reflected light from the fundus Er is received again from the pupil Ep via the objective lens 8 and is provided with a perforated total reflection mirror M3.
The light passes through the filter F2, the focusing lens 9, and the imaging lens 10 through the hole, and enters the return mirror M4. still,
The first barrier filter F2 is a barrier filter for alignment at the latter stage of infrared fluorescence imaging, cuts a wavelength of 780 nm or less and transmits a wavelength of 780 nm or more, and is in the optical path only at the latter alignment of infrared fluorescence imaging. Inserted. On the other hand, the second barrier filter F3 is a barrier filter for infrared fluorescence imaging, cuts a wavelength of 815 nm or less, transmits a wavelength of 815 nm or more, and is inserted into the optical path only at the time of infrared fluorescence imaging. Each filter F2
F3 and F3 are both separated from the optical path during normal photographing.

The light incident on the return mirror M4 is reflected by the return mirror M4 and the mirror M5 during observation, and is observed by the examiner S through the field stop 12 and the field lens 13 by the eyepiece 14. Return mirror M4
Is configured so that it can be removed from the optical path.
In the case of photographing at 1, the return mirror M4 is removed from the optical path, the strobe SR as the photographing light source emits light, and a fundus image is photographed on the film 11.

When recording as an electronic image by the color camera 24, the mirror M5 is separated from the optical path, and an image is taken by the color camera 24 via another field stop 20, field lens 21 and lens 23. In the case of a color camera, the recording is usually recorded as a still image by the still image recording device 28. At this time, the mirror 22 has been separated from the optical path. Further, when performing infrared fluorescence imaging, the mirror 22 is inserted into the optical path, the fundus image is captured by the monochrome camera 26 via the lens 25, and is observed by the monitor 29. In the case of infrared fluorescent imaging, the recording is normally recorded by the moving image recording device 27 as a moving image. The fundus images recorded by the still image recording device 28 and the moving image recording device 27 can be observed on the monitor 29.

Next, details of the infrared fluorescence imaging will be described with reference to the flow of FIG. If it is confirmed in step S1 of FIG. 2 that the imaging is infrared fluorescence imaging, the infrared fluorescence imaging exciter filter F1 and the infrared fluorescence imaging barrier filter F3 are inserted into the optical path in step S2. Further, since it is assumed that recording is performed by the moving image recording device 27 via the monochrome camera 26, the mirror 22
Is inserted into the optical path, and the mirror M5 is separated from the optical path (the mirror M4 is in a position shown by a solid line). Subsequently, at step S3, an infrared fluorescent agent (for example, indocyanine green) is intravenously injected, and at step S4, infrared fluorescent imaging by the moving image recording device 27 via the monochrome camera 26 is started.

In the first half of the infrared fluorescence imaging, continuous video imaging with a lamp is possible because the amount of infrared fluorescence is high. However, in the latter stage, when both the filters F1 and F3 are inserted and the image becomes dark enough to be unobservable, recording of a still image by the still image recording device 28 capable of instantaneously obtaining high luminance is performed. Switch to. For this reason, if it is confirmed in step S5 that it is late in the infrared fluorescence imaging, the alignment barrier filter F2 is inserted into the optical path for alignment in step S6, and the imaging barrier filter F3 is once removed from the optical path. Be separated.

In the latter half of the infrared fluorescence photographing, when the alignment and focusing are completed (step S
7) In step S8, the shutter is released and the flash S
R is caused to emit light. At this time, the filter F3 is inserted into the optical path in place of the filter F2 immediately before the strobe light is emitted, and at the same time when the image capturing is completed, the filter F3 is turned off.
3, so that the filter F2 is inserted into the optical path.

Infrared fluorescence imaging is performed in the above-described procedure.

[0019]

As described above, according to the present invention, in the latter stage of infrared fluorescence imaging, a barrier filter for infrared fluorescence imaging is inserted at the time of capturing an image, and at other times, a barrier filter for alignment is used. Is inserted, alignment or focusing is easy even in the latter stage of infrared fluorescence imaging, and good infrared fluorescence imaging is guaranteed.

[Brief description of the drawings]

FIG. 1 is an optical diagram showing a configuration of a fundus camera according to the present invention.

FIG. 2 is a flowchart illustrating a flow of infrared fluorescence imaging.

[Explanation of symbols]

LA Lamp SR Strobe F1 Exciter Filter for Infrared Fluorescence Imaging F2 Barrier Filter for Alignment for Infrared Fluorescence Imaging F3 Barrier Filter for Infrared Fluorescence Imaging E Eye to be Examined S Examiner 24 Color Camera 26 Black and White Camera 27 Video Recording Device 28 Still Image Recording device

Claims (3)

[Claims] 1. Fluorescence imaging for irradiating light from an observation light source to a fundus of an eye to be examined via an illumination system, and forming reflected light from the fundus via an imaging optical system to observe the fundus is possible. In the fundus camera, an infrared fluorescence imaging exciter filter that can be inserted into and removed from the illumination system, an infrared fluorescence imaging alignment first barrier filter that can be inserted into and removed from the imaging optical system, A second barrier filter for infrared fluorescence imaging that can be replaced with a barrier filter, wherein in the latter stage of infrared fluorescence imaging, the first barrier filter is used during alignment and the second barrier filter is used during infrared fluorescence imaging. A fundus camera, which is inserted into a camera. 2. The fundus camera according to claim 1, wherein a transmission band of the first barrier filter is shorter than a transmission band of the second barrier filter. 3. The exciter filter according to claim 3, wherein
815 nm, the first barrier filter cuts the wavelength of 780 nm or less and transmits the wavelength of 780 nm or more, and the second barrier filter transmits the wavelength of 780 nm or more.
The fundus camera according to claim 1 or 2, wherein the filter is a filter that cuts a wavelength of 815 nm or more and cuts a wavelength of 815 nm or less.