JPH06277186A - Ophthalmic observation and photographing device - Google Patents

Abstract

(57) [Summary] [Purpose] To improve the contrast of a fluorescent image while making it easier to understand the positional relationship of the parts that emit fluorescence, and to facilitate the extraction of fluorescent leaked parts and the measurement of the leaked area and intensity. An illumination optical system 1 for illuminating an eye to be inspected, an exciter filter 15a insertable into the illumination optical system,
In an ophthalmic observation and photographing apparatus capable of fluorescence photographing, which includes an observation and photographing optical system for observing and photographing the eye to be inspected illuminated by the illumination optical system, and a barrier filter 31a insertable into the observation and photographing optical system, A fluorescent image capturing means 7 for capturing a fluorescent image with an exciter filter inserted in the system and a barrier filter inserted in the observation and photographing optical system;
By the general image capturing means 5 for capturing a general image in a state where either one or both of the exciter filter and the barrier filter are not included in the optical system, the fluorescence image obtained by the fluorescence image capturing means and the general image capturing means. Composite display means 41, 43, 45 for composite display of the obtained general image
Equipped with.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ophthalmic observation and photographing apparatus capable of fluorescence photographing, which has an exciter filter that can be inserted into an illumination optical system and a barrier filter that can be inserted into an observation and photographing optical system.

[0002]

2. Description of the Related Art Fluorescence image recording and recording in an ophthalmic observation and photographing device such as a slit lamp microscope and a fundus camera is performed by inserting an exciter filter in the illumination optical system and a barrier filter in the observation and photographing optical system, and On the other hand, it is carried out by improving the contrast of a portion of the blood vessel or the like that emits fluorescence.

[0003]

In the prior art, in order to improve the contrast of the fluorescence image, it is necessary to reduce the overlapping portion of the transmission wavelength characteristics of the exciter filter and the barrier filter by using an interference filter or the like. there were. In that case, the contrast of the fluorescent image is improved,
The background becomes dark, and it is difficult to understand the positional relationship of the part that emits fluorescence as in the case of iris fluorescence photography.

On the contrary, in order to brighten the background, it is necessary to increase the overlapped portion of the transmission wavelength characteristics of the exciter filter and the barrier filter by using a gelatin filter or the like. However, in that case, the background becomes bright and the positional relationship of the part that emits fluorescence becomes easy to understand, but the contrast of the fluorescence image deteriorates, and it is difficult to extract the leakage part of the fluorescence and measure the leakage area, intensity, etc. was there.

Therefore, an object of the present invention is to improve the contrast of a fluorescent image while making it easy to understand the positional relationship of the fluorescent portion, and to facilitate the extraction of the fluorescent leaked portion and the measurement of the leaked area and the intensity. And

[0006]

To achieve the above object, an ophthalmic observation and photographing apparatus according to the present invention comprises an illumination optical system for illuminating an eye to be inspected, and an exciter filter insertable into the illumination optical system. In an ophthalmic observation and photographing apparatus capable of fluorescence photographing, comprising an observation and photographing optical system for observing and photographing the eye to be inspected illuminated by the illumination optical system, and a barrier filter insertable into the observation and photographing optical system, An exciter filter is inserted into an optical system, and a fluorescence image capturing unit that captures a fluorescence image in a state where a barrier filter is inserted into the observation and photographing optical system, and either one or both of the exciter filter and the barrier filter is the optical system. General image capturing means for capturing a general image in a state not included therein, a fluorescent image obtained by the fluorescent image capturing means, and the general image capturing means Characterized in that it comprises a composite display means for synthesizing display a general image more obtained.

The fluorescent image capturing means and the general image capturing means may be separate image capturing means or the same image capturing means. When the same image pickup means also serves, both images are continuously photographed in a short time. When using separate imaging means, both images can be taken simultaneously. In this case, of course, it is also possible to continuously shoot.

[0008]

In the present invention, either or both of the exciter filter and the barrier filter are not included in the optical system at the same time when the fluorescence image is taken using the exciter filter and the barrier filter or continuously within a short time. A general image is taken, a fluorescence image and a general image are obtained on the observation display unit, and both images are combined. Alternatively, an image obtained by multiplying the fluorescence image and the general image by a preset coefficient is obtained, and both images are combined.

As a result, even if an exciter filter and a barrier filter having a filter characteristic with a large overlapping portion are used, it is possible to obtain an analysis image with good contrast by arithmetically combining the fluorescence image and the general image. From this analysis image and general image, while making it easier to understand the positional relationship of the part that emits fluorescence, the contrast of the fluorescence image is improved, and it becomes possible to easily extract the fluorescence leakage part and measure the leakage area, intensity, etc. .

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view of a first embodiment of an ophthalmologic observation and photographing device in which a slit lamp is used as an example. However,
The present invention is not limited to slit lamps.

In FIG. 1, reference numeral 1 denotes an illumination optical system for illuminating an eye P to be examined. In the illumination optical system 1, the illumination light from the illumination light source 11 sequentially passes through the condenser lens group 1
A, the photographing light source 12, the condenser lens group 1b, and the slit width adjusting mechanism 13 and the illumination field diaphragm 14. The photographing light source 12 is at a position conjugate with the illumination light source 11, and emits light during photographing. Further, the slit width adjusting mechanism 13 and the illumination field diaphragm 14 change the size of the illumination aperture according to the purpose of photographing. The illumination light whose size of the illumination aperture has been adjusted is filtered by various filters 1
5, the light passes through the lens 1c, is reflected at a right angle by the reflecting mirror 1d, and further reaches the eye P through the diffuser plate 1e which can be inserted when necessary. The various filters 15 can be replaced manually or electrically with a turret plate or the like, and the exciter filter 15a is inserted therein during fluorescence imaging.

Reference numeral 2 denotes an objective microscope section of an observation optical system for observing an eye to be inspected, which includes an objective lens 2a and a variable power lens group 2.
It consists of b.

Reference numeral 3 denotes an intermediate lens barrel, which is a half prism 3
a can be inserted and is retracted from the optical path for the purpose of observation only, and is inserted into the optical path for the purpose of imaging, and the optical path is divided into two. or,
The barrier filter 31a is inserted here at the time of fluorescence imaging.

Reference numeral 4 is a first TV apparatus, which is composed of a relay lens 4a and a reflecting prism 4b.

Reference numeral 5 is a first TV camera, and 5a is its image pickup surface.

Reference numeral 6 is a second TV apparatus, which is composed of a reflecting mirror 6a, a relay lens 6b, a reflecting prism 6c, and a relay lens 6d which are inserted at the time of photographing.

Reference numeral 7 is a second TV camera, and 7a is its image pickup surface.

Reference numeral 8 denotes a binocular barrel, and the observation light beam is guided to the observation image forming surface 8d via the relay lens 8a and the erecting prisms 8b and 8c.

Reference numeral 9 denotes an eyepiece lens, which is a relay lens 9a.
The image of the observation image forming surface 8d, that is, the barrier filter 31
Both the fluorescence image and the general image are selectively observed by the optometry Q by inserting / removing a.

Although the objective lens 2a is common to both eyes, the optical path is divided into right and left (from the variable power lens 2b) thereafter. In the figure, only one optical path is shown.

During fluorescence photography, the exciter filter 15a is used as the illumination optical system and the half prism 3a is used as the observation photography optical system.
And the barrier filter 31a is inserted. Therefore, the release button 1 installed on the joystick 121
By pressing 22, the reflecting mirror 6a in the second TV device 6
Is inserted into the observation optical system and the photographing light source 12 emits light. In response to this, the first TV camera 5 and the second TV camera 7
A general image 5a of the eye P to be examined, in which an exciter filter is inserted in the illumination optical system and the photographing optical system does not include a barrier filter, and a fluorescent image 7a in which the illumination optical system includes an exciter filter and the photographing optical system includes a barrier filter. And are recorded at the same time.

FIG. 2 shows an example of transmission wavelength characteristics of the exciter filter and the barrier filter. In the fluorescence image, the background is observed by the overlapping part A of both transmission wavelength characteristics, and the positional relationship of the part that emits fluorescence can be understood to some extent, but on the contrary, this background deteriorates the contrast of the fluorescence image and causes the fluorescence leakage part. It is difficult to extract and measure leaked area and strength. L is called a separation wavelength, and a wavelength of around 500 nm or 520 nm is usually used in many cases. However, separation can be performed by appropriately selecting an exciter filter and a barrier filter according to the absorption characteristics and emission characteristics of the fluorescent agent or dye used. The wavelength can be changed freely. Generally, it is possible to reduce the overlapping portion of the transmission wavelength characteristics by combining the interference filters as compared with the combination of the gelatin filters. However, depending on the purpose, the combination of the gelatin filters or the interference filter and the gelatin filter may be combined. It is possible to combine.

FIG. 3 shows the transmission wavelength characteristic of only the exciter filter. In this embodiment, since a general image is photographed using the exciter filter, this shows the transmission wavelength characteristic of the general image optical system. It will be a matter. Instead of the exciter filter, it is also possible to replace the color balance filter or the total transmission filter.

FIG. 4 is a block diagram showing the flow of images. The general image 5a from the first TV camera 5 and the second T
The fluorescence image 7a from the V camera 7 is transferred to the computer 43 via the frame memory or the video board 41, respectively.
To the monitor 4 by the processing of this computer 43.
5, a fluorescence image and a general image are selectively displayed, and further, the fluorescence image and the general image are multiplied by a coefficient preset according to the characteristics of the exciter filter and the barrier filter used and the optical system for the general image. The analysis image obtained by the calculation is displayed. Specifically, the analysis image is obtained by subtracting the image obtained by multiplying the general image by a certain coefficient from the fluorescence image so that the background light amount is minimized. Here, the calculation coefficient is the transmission wavelength characteristic of the exciter filter and the barrier filter shown in FIG. 2 and the area of the overlapping portion A,
It is determined by the transmission wavelength characteristic and the integrated value of the amount of transmitted light of the general image optical system shown in FIG. As a result, even when the area of the overlapping portion A is large, it is possible to obtain a fluorescent image with good contrast.

Regarding this arithmetic processing, more specifically,
This will be described using mathematical expressions.

The transmittance of the barrier filter with respect to the wavelength λ is ρ ₁ (λ), the light intensity of a certain portion is f (λ), the absorption of the fluorescent agent is g (λ), the efficiency of the fluorescent agent is κ, the wavelength of the fluorescent agent is It is assumed that the shift amount is λ ₀ , the wavelength at which the transmittance of the exciter filter on the falling side is almost 0, and the wavelength at which the transmittance of the barrier filter is almost 0 on the rising side is λb.

The intensity Ie after passing through the exciter filter at the site where fluorescence is emitted is The intensity Ien after passing through the exciter filter at the part where fluorescence is not emitted (background part) is Can be expressed as

Further, the intensity Ib after passing through the barrier filter at the site where fluorescence is emitted is The intensity Ibn after passing through the barrier filter at the site where fluorescence is not emitted is Is represented.

Since the background color tone is almost uniform, there is a coefficient ε such that Ien-εIbn = 0.

However, in the fluorescent part, from the equations 1 and 3, Equation 5 can be transformed as follows.

[0032] If the color tones are the same, the first and second terms of Equation 6 are 0, so in the long wavelength region such as> λb, ρ ₁ (λe) <
Since ρ ₁ (λb), ρ ₁ (λe) = ρ ₁ (λb) + ρ
> 0 exists, and the third term of the equation 6 is at worst κε∫ρg (λ−λ ₀ )} dλ ≠ 0. As described above, it is understood that only the fluorescence image can be extracted by the calculation of Expression 5 using the coefficient ε.

Incidentally, the fluorescence image and the general image used for the calculation can be subjected to image processing such as contrast enhancement if necessary.

In this embodiment, a still image from the photographing light source 12 is used, but a still image or moving image using the illumination light source 11 is calculated by leaving the reflecting mirror 6a inserted in the observation optical system. It is also possible to display. Further, the image may be once shot on a video floppy by a still video device or the like, and then transferred to a computer.

Further, the position of the barrier filter 31a is changed,
By changing the positions of the intermediate lens barrel 3 and the second TV device 6, for example, a fluorescence image is displayed on the first TV camera 5, and a second TV device 5 is displayed.
It is also possible that the general image is photographed and recorded by the camera 7, or only the general image can be observed from the eyepiece lens 9.

In addition, the half prism 3a is a semi-transmissive mirror, or the reflecting mirror 6a inserted at the time of photographing is a half prism or a semi-transmissive mirror and remains inserted even when observed by the eyepiece lens 9. It is possible to change the position of the and mirrors and change to a member having the same function.

Alternatively, if the half prism 3a is used as a reflecting mirror and can be moved into and out of the optical path at a high speed and is linked with the reflecting mirror 6a, a general image and a fluorescent image can be continuously photographed and recorded. Further, the barrier filter 31a
If this is also linked, general images and fluorescent images can be continuously observed and photographed and recorded alternately.

The intermediate lens barrel 3 is eliminated and the barrier filter 3
If only 1a can be moved in and out of the optical path at high speed, it is possible to continuously and alternately record and record a general image and a fluorescent image on the second TV camera 2.

Further, although two TV devices are used here, each 35 mm photographic device is used to
It is also possible to take an image on m-film and then take an image from an input device such as a film scanner or a still image camera into a computer and perform the same procedure. Also, 35 mm
Images from a large format camera or an instant camera as well as a camera may be used.

The above embodiment is premised on a mono image, but the same treatment may be performed so that a stereo image, that is, a pair of stereo fluorescent images and a general image are simultaneously photographed and recorded. .

FIG. 5 is a schematic view showing a second embodiment, in which the illumination optical system 1, the objective microscope section 2, the binocular barrel section 8 and the eyepiece lens 9 are the same as in the first embodiment. Therefore, only the parts that are different from the first embodiment will be described here.

In FIG. 5, 3'is an intermediate lens barrel,
The half prism 3'a divides the optical path into two, and the reflecting mirrors 3'b, 3'c, and 3'd match the optical paths again. Further, the barrier filter 31a is inserted into one of the divided optical paths at the time of fluorescence photography. Here, an ND filter or the like may be inserted in each optical path to adjust the brightness of the image or the like.

Reference numeral 4'denotes a first TV device, which comprises a relay lens 4'a.

5'is a first TV camera, and 5'a is its image pickup surface.

Reference numeral 6'denotes a second TV device, which comprises a relay lens 6'a.

7'is a second TV camera, and 7'a is its image pickup surface.

An image of the observation image forming surface 8d, that is, a fluorescence image or a general image in which the barrier filter 31a is inserted by the binoculars tube portion 8 and the eyepiece lens 9 is observed by the optometry Q by inserting and removing the reflecting mirror 3'd. .

At the time of fluorescence photography, the exciter filter 15a is inserted into the illumination optical system and the barrier filter 31a is inserted into the observation photography optical system. By pressing the release button 122 installed on the joystick 121, the reflecting mirrors 3'b and 3'c are retracted from the observation optical system, the photographing light source 12 emits light, and the first TV camera 5'and the second TV Camera 7 '
, A general image 5'a in which an exciter filter is inserted in the illumination optical system of the eye P to be inspected and a barrier filter is not included in the imaging optical system, and
Fluorescent image 7'a including a barrier filter in the photographing optical system
Are recorded at the same time.

The description of the filter characteristics of FIGS. 2 and 3 and the monitor display of FIG. 4 is the same as that of the first embodiment.

If a reflecting mirror is inserted as needed instead of the half prism 3'a, only general images and fluorescent images can be observed and photographed and recorded. Further, if these members are switched at high speed, general images and fluorescent images can be continuously and alternately observed.

Further, a still image or a moving image is arithmetically displayed on the monitor by an illumination light source, a video floppy is once photographed and then transferred to a computer, a general image and a fluorescent image are exchanged, positions of a half prism and a reflecting mirror are exchanged. Or change to a member with the same function, once shoot 35 mm film using a 35 mm photographic device, then import the image from the film scanner or still image camera to the computer, use the image from a large format camera or instant camera, stereo image It is the same as the first embodiment that it is possible to record and record the images.

Finally, although the present invention describes the observation / photographing apparatus for fluorescent images, it goes without saying that special images using other special filters can also be targeted. It is also possible to obtain a more efficient image by combining with a polarizing filter.

[0053]

As described above, according to the present invention, a general image is taken simultaneously with taking a fluorescent image or within a short time, and these fluorescent image and ordinary image are combined and displayed. Even if an exciter filter and a barrier filter having filter characteristics with a large overlapping portion are used, it is possible to obtain a fluorescent image with good contrast. As described above, the contrast of the fluorescence image is improved, and the positional relationship of the fluorescence emitting portion can be determined from the general image, so that the fluorescence leakage portion can be easily extracted and the leakage area, intensity, etc. can be easily measured.

The coefficient to be applied to the fluorescence image and the general image before the composition is made variable by changing the characteristics of the exciter filter and the barrier filter used, the general image optical system, and the characteristics of the fluorescent agent and the dye used. , The selection range of filters, fluorescent agents and dyes to be used expands. When calculating fluorescence images and general images, image processing such as contrast enhancement may be possible depending on the situation, which not only makes it easier to understand the positional relationship of the parts that fluoresce, but also confirms the areas where the fluorescence leaks and the leakage area. It also becomes easier to measure strength, etc.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a first embodiment of the present invention.

FIG. 2 is a graph showing transmission wavelength characteristics of an exciter filter and a barrier filter.

FIG. 3 is a graph showing a transmission wavelength characteristic of only an exciter filter.

FIG. 4 is a block diagram showing a system for processing an image according to an embodiment.

FIG. 5 is a schematic diagram of a second embodiment of the present invention.

[Explanation of symbols]

 1 Illumination optical system 2 Objective microscope part 3, 3'Intermediate barrel 4,4 'First TV device 5,5' First TV camera 6,6 'Second TV device 7,7' Second TV Camera 8 Binocular barrel 9 Eyepiece P Eye to be examined Q Eye to be examined 15a Exciter filter 31a Barrier filter

Claims (7)

[Claims] 1. An illumination optical system for illuminating an eye to be inspected, an exciter filter insertable into the illumination optical system, and an observation and photographing optical system for observing and photographing the eye to be inspected illuminated by the illumination optical system. In an ophthalmic observation and photographing device capable of fluorescence photographing, which comprises a barrier filter that can be inserted into the observation and photographing optical system, an exciter filter is inserted into the illumination optical system, and a barrier filter is inserted into the observation and photographing optical system. A fluorescent image capturing means for capturing a fluorescent image in a state, a general image capturing means for capturing a general image in a state where either one or both of an exciter filter and a barrier filter is not included in the optical system, and the fluorescent image And a composite display unit configured to compositely display the fluorescence image obtained by the image capturing unit and the general image obtained by the general image capturing unit. Ophthalmic observation and photographing device. 2. The ophthalmologic observation and photographing apparatus according to claim 1, wherein the composite display means has a function of performing an arithmetic operation on the fluorescence image and the general image to combine them. 3. The ophthalmic observation and photographing apparatus according to claim 2, wherein the calculation is to multiply the fluorescence image and the general image by a coefficient set in advance. 4. The ophthalmic observation and photographing apparatus according to claim 2, wherein the calculation is a calculation for subtracting a general image multiplied by a preset coefficient from the fluorescence image. 5. The coefficient of the calculation is variable according to the characteristics of an exciter filter and a barrier filter used, a general image optical system, and the characteristics of a fluorescent agent and a dye used. The described ophthalmic observation and photographing device. 6. A fluorescent image and a general image used for the calculation are further provided with image processing means for performing image processing such as contrast enhancement, respectively. Ophthalmic observation and photographing device. 7. The ophthalmic observation and photographing apparatus according to claim 1, wherein the image synthesizing means includes a monitor for displaying the synthesized image.