DE102007052858A1 - Retina examination method for patient, involves producing data items and two-dimensional depth slice images from retina, where position of items in recorded two-dimensional image is known and/or preset based on two-dimensional images - Google Patents

Abstract

The method involves producing data items and two-dimensional depth slice images i.e. optical coherence tomography live-B-scan-images, from retina. A position of the data items in the recorded two-dimensional image of the retina is known and/or preset based on the two-dimensional images. The position and/or alignment of the slice images is actively controlled depending on surface images i.e. angiography images, by the actualization of the surface images. The actualized images and the slice images are simultaneously represented in preset small time intervals by display units. An independent claim is also included for an apparatus for examination of retina.

Description

The The invention relates to a method for retinal diagnosis according to the characteristics of claim 1. Furthermore, the invention relates to a Device for execution of the procedure.

From the EP 1 487 322 B1 Such a method is known, which is used for the examination of vessels of the retina of an eye and allows the determination of the vessel wall thickness. Here, by means of laser scanning on the one hand, the outer diameter and on the other hand, the inner diameter of the vessel and finally determined from the thus determined data, the wall thickness of the vessel. The determination of the outer vessel diameter is made from the data of a reflection image and the inner diameter corresponding to the diameter of the moving blood column from the data of a laser Doppler image. A comprehensive examination or diagnosis of the retina is not readily possible here. The laser scanning technique is used for the generation of reflection images, angiography images and autofluorescence images of the retina. Here, the retina is scanned point by point with a laser beam of a certain wavelength in a two-dimensional field, and there are continuously running (live) images or reference images, wherein 10 to 50 images per second are typical. Angiography, in particular in the form of fluorescein angiography (FA) and indocyanine green angiography (ICGA), is an important diagnostic procedure, whereby essentially two-dimensional images of the retinal surface and possibly lower layers of the retina are produced by point-by-point illumination and scanning Scanning. Furthermore, such surface images of the retina can be generated by surface illumination and detection of a suitable image sensor, such as a CCD camera (Charge Coupled Device) or a fundus camera. Furthermore, the spectral domains Optical Coherence Tomography (OCT) are used for retinal diagnosis, which provides two-dimensional sectional images essentially perpendicular to the retinal surface, so-called B-scans, which are linearly composed of depth-scanning A-scans. To produce the first-mentioned surface images and the depth-sectional images two different devices are required, whereby a considerable effort is required. The examination or diagnosis of the retina of the eye makes in view of the various known methods high demands on an examiner but also to a patient and is also time consuming, especially since the investigations are to be carried out successively using different devices.

Of these, The invention is based on the object, a method to propose, which in a simple way a comprehensive investigation or diagnosis of the retina of the eye. The procedure should be easily and functionally feasible and with little effort reliable Deliver results and make the diagnosis easier for the examiner. The device for execution The method should have a simple and / or functionally reliable construction have a low operating cost and require an optimized and / or provide comprehensive retinal diagnostics.

The solution This object is achieved with regard to the method according to the Claim 1 features specified. Regarding the device the solution according to the characteristics of the device directed claim.

The proposed according to the invention Procedure and the device proposed for its implementation allow the implementation from extensive examinations of the retina due to the generation of area images in combination with deep-section images of the retina, while simultaneously or sequentially or simultaneously a surface image and a depth sectional image by means of one or more display units, such as monitors or Displays are displayed. In a preferred manner, a Un can tersucher in the area image considering one of this area of interest, in particular a visible pathology, any position and / or direction of the depth sectional image and / or pretend. The method and the device arrive in a preferred manner for comprehensive retinal diagnosis.

The surface images are preferably two-dimensional images of at least partial areas the retinal surface and / or to this at least approximately parallel surfaces the retina. The area pictures are preferably produced by angiography, but can in the Frame of the invention instead of reflection images arbitrary Wavelength or Autofluoreszenzbilder or by surface illumination and means Camera, such as CCD sensor, detected Pictures are used and presented. The depth section pictures from the retina are preferred by optical coherence tomography (OCT) generated, but can in the context of the invention, other methods, such as ultrasound, to be used.

The device according to the invention is characterized by the integration and / or combination of two independent system components, by means of which, on the one hand, the area images and, on the other hand, the depth sectional images are generated. Thus, one system component preferably contains a laser scan system with different laser sources for receiving reflection and angiography images, two oscillating mirrors for sequentially scanning the focused laser beam on a two-dimensional region of the retina, and a detector for measuring the amount of light reflected or emitted at each point. The other system component preferably includes a wide band light source spectral domain OCT system such as superluminescent diode, two further retinal scanning mirrors and a spectrometer. However, other OCT techniques can be used. The beam paths of the two system components are matched to one another at a location which lies between the examined eye and the scanning mirrors, in particular by means of an optical unit and / or optical partial and imaging unit. With the device, a simultaneous and / or simultaneous recording of one of the area images, which is also referred to as a live reference image, in successive, preferably short time intervals, takes place with one of the depth cross-sectional images, which is also known as OCT scan or OCT live Picture is called. A reference image is preferably either an angiography image or a reflection image or an autofluorescence image. The point on the retina at which the depth-sectional image, in particular the OCT-live image, is generated and the direction of the depth-sectional image can be freely selected and / or specified by the operator or examiner, for example by clicking on the reference image.

Farther is in accordance with the method and / or with the device the measurement of the eye movement of a patient on the basis thereof resulting movements of the visible structures in the reference image carried out. Preferably, the stabilization of the depth cross-sectional image, in particular the OCT live image, such that the means of the reference image measured eye movements on the optic, e.g. Scanmirror, the Feedback OCT system component be and / or such that the point of the retina, at which the OCT live image is captured, which follows eye movements, and thus a stable image always recorded in the same place and / or is produced. Furthermore, according to the invention, an averaging of several successive, as explained above, stabilized OCT live images take place, about the signal-to-noise ratio and thus the quality to increase the OCT live images. Furthermore, in a preferred manner, the representation of the averaged images, for example, as a moving average, instead of the normal one Depth sectional image, in particular the OCT live image.

According to one preferred embodiment of the invention takes place during the Stabilizing an automatic recording of several parallel to each other running but slightly offset depth sectional images and / or OCT images. Each of these images can be a time average of several be consecutive pictures in the same place and the Set of such averaged images together forms a three-dimensional Depth sectional image and / or three-dimensional OCT image.

According to a particular refinement, the exact position and direction in the reference image and the reference image itself of a depth-sectional image and / or OCT image recorded during an examination are stored, in particular in a suitable memory. Furthermore, by means of the information thus stored, an automatic adjustment of the deflection and / or scanning unit, in particular the scanning mirror of the OCT system component, takes place in a subsequent examination or follow-up examination in such a way that the depth-sectional image and / or OCT image of the follow-up examination is exactly the same the same post as in the previous investigation. Thus, in a preferred manner, a direct comparison of said images to changes in the retina can be made. The method according to the invention and also with the device according to the invention generate first data and first two-dimensional and / or surface images of at least areas of the retina and also generate second data and two-dimensional depth sectional images from the retina, the position and / or orientation of the one or more depth slice images with respect to the retinal surface. The location or the area of interest, in particular the pathology visible in the two-dimensional image or area image, on which the depth-sectional image is generated, and furthermore its orientation is thus selected and / or predetermined on the basis of the area image or reference image. It is furthermore of particular importance that the first area image and the depth sectional image are displayed simultaneously or simultaneously or also in predefinable or predetermined temporal, preferably short intervals. The depth-sectional image is stabilized by feedback, in particular the scanning or deflection unit, such that the point or the area of the retina on which the depth-sectional image is obtained follows and / or tracks the eye movements. In addition, in a preferred manner, averaging is carried out from a plurality of successive, in particular stabilized, depth-sectional images, whereby preferably the one or more averaged depth-sectional images are also represented in particular as a moving average. In addition, an automatic recording or generation of a plurality of substantially parallel to each other and offset in predetermined small distances depth sectional images takes place during the stabilization. Preference is given to several sequential, be preferably stabilized sectional images produced a three-dimensional image. Further, the position and / or orientation of the preferably stabilized depth slice image and / or the three-dimensional depth slice image and further preferably the associated area or reference image are stored.

The inventive method as well as the implementation proposed device are the combination of generating retinal surface images with the generation of second data and two-dimensional depth sectional images from the retina, with the position of the second data recorded in the two-dimensional surface image the retina is known and / or stored. The position and / or the alignment of one or more depth slice images is based on the area image controlled and / or actively controlled and / or predetermined and so on becomes the position and / or orientation of one or more depth slice images based on a previously captured two-dimensional image or area image predetermined and / or actively controlled. Furthermore, the preferred Position and / or orientation of one or more depth slice images predetermined by a first recorded area image and a Updating the area image actively controlled. Preference is given to the movement of the updated surface image determined relative to the first recorded area image and the position recording or creating one or more depth-cut images controlled at the predetermined locations or locations of the retina. It is of particular importance that the first area image or the updated surface image and the depth sectional image simultaneously and / or simultaneously or in predefinable time intervals be represented by one or more display units. The area-sectional image is preferred through feedback stabilized such that the part of the retina on which the Surface interface image is obtained, follows the eye movements and / or tracked. Furthermore, it has proved to be useful that from several consecutive stabilized depth-slice images averaging carried out is and / or that the one or more averaged surface section images in particular represented as a moving average. In a preferred manner takes place during stabilizing an automatic recording of several parallel or according to one arbitrary and / or predeterminable pattern running and in specifiable small distances offset depth section images. From these depth-sectional images and / or from several successive depth sectional images is in preferred Way creates a three-dimensional depth-sectional image.

Of Further, the position of the depth sectional image in the reference image becomes and the reference image itself is saved and it becomes the depth sectional image in a follow-up examination in exactly the same place and / or recorded or generated with the same orientation as one previous investigation and also stored for further investigation.

The two-dimensional surface image becomes expedient over reflected or re-emitted light in one or more selected wavelength ranges generated or it is to record the area image with the retina Light of a selected Wavelength range or more selected ones Wavelength ranges illuminated. Further, for receiving or generating the two-dimensional surface image the illumination by means of a point, which raster-shaped the Scanned area of the retina or the lighting with take a line that over the predetermined area of the retina is performed. The detection can by means of point detector or by line camera or by area camera respectively. The recording of the OCT sectional images is advantageous according to a Fourier Domain OCT method or a Time Domain OCT method. Preferably, the two-dimensional area image is an angiography image. In a particular embodiment of the invention, a first Angiography image and a second two-dimensional area image - e.g. one Reflection image - the retina simultaneously or in a very short time interval simultaneously taken, with the control and control of recording the Depth sectional images based on an update of the second two-dimensional surface image the retina takes place. In case of a later follow-up examination can then this second area image instead of the first surface image to control, control and stabilize the depth-sectional images be used. Of particular importance according to the invention is the generation the area pictures as Angiography images in combination with OCT-Schnittbildern and their simultaneous presentation.

The Invention will be described below with reference to a particular embodiment explained in more detail, without that in that respect a restriction he follows. Show it:

1 a block diagram,

2 the images displayed side by side in a display unit, on the left side, the area image as an angiography image and on the right the depth sectional image as an OCT live B-scan image.

According to 1 contains the device for comprehensive examination of the retina of the eye schematically illustrated 2 an image capture unit 4 for first two-dimensional images or areal images of the retina. The image capture unit 4 contains a lighting unit and a measuring unit. As by means of the arrows 6 . 7 . 8th indicated, the illumination unit illuminates the retina, at a point, on a line or on a surface. In this case, the light passes through a scanning control unit 10 and an optical unit 12 to the retina. The scan control unit 10 contains scanning mirror or the like in a known manner and is like the image acquisition unit 4 from a control and processing unit 14 controlled. A scanning unit 16 is intended for the production of deep-section images from the retina. The light reflected and / or re-emitted by the retina passes ge according to the arrows, 8th . 7 . 6 into the image capture unit 4 whose measuring unit is the intensity of the total light reflected and / or re-emitted by a point of the retina or the intensity of the light reflected and / or re-emitted in a selected wavelength range. The measuring unit is designed either as a point detector or a line camera or an area camera.

The OCT scanning beam for the OCT image acquisition scans an area on the retina pointwise or line by line, with a depth profile, a so-called OCT-A scan, being recorded for each point. As with the arrows 18 . 19 . 20 indicated, passes from the scanning unit 16 the light through the OCT scan control 20 and the optical unit 12 to the retina and back. The OCT scanner 16 and the OCT scan control 21 are also using the control and processing unit 14 controlled. Due to the control of the scan control unit 10 and the OCT scan control 21 are the coordinates of the OCT recording and the unit 4 known and can thus be controlled relative to each other. In particular, the OCT scanning beam may be relatively controlled to fixed positions and / or areas of interest. In the case of eye movements, especially in the period between individual shots of the image acquisition unit 4 , the OCT scanning beam can preferably be traced.

The image capture unit 4 and the scanning unit 10 form a first system component 22 and the OCT scanner 16 with the OCT scan control 21 form a second system component 24 whose beam paths at one point and / or by means of the optical unit 12 to be united. The optical unit 12 is a common part and mapping unit of the two system components 22 . 24 and / or their beam paths. As can be seen, the optical unit 12 according to the invention in the beam paths between the eye 2 and on the one hand the scan control unit 10 for the area images and on the other hand the scanning control 21 for the depth cross-sectional images, in particular the OCT Abtaststeuerung arranged. To the control and processing unit 14 is another unit 26 connected for operation and evaluation, which also advantageously contains a database and / or memory and / or a CPU or other computer modules. Finally, to the control and processing unit 14 a display unit 28 connected, by means of which the area image, in particular angiography image, and the OCT live B-scan image are displayed.

2 shows the two images represented by the image display unit, on the left, the angiography image 30 and on the right the OCT live B-scan image 32 , In angiography image 30 is by means of the line 34 the point at which the depth-sectional image or OCT-live-B-scan image is recorded is marked. The line 34 is through an area 36 placed in the right OCT live B-scan image 32 are other important details of this area 36 of interest to an investigator clearly identifiable and assessable. The positioning of the line 34 and / or their orientation in the area image 30 and thus with regard to the retina, the operator or examiner can easily specify according to his experience or wishes and only exemplary is another line 35 dashed lines with changed position and orientation, for which a correspondingly changed depth sectional image or OCT live B-scan image can be displayed.

2

eye

4

Image capture unit

6-8

arrow

10

scanning

12

common optical unit

14

inspection and processing unit

16

scan control

18-20

arrow

21

OCT scan controller

22

first system component

24

second system component

26

Further unit

28

Image display unit

30

Surface image / angiographic image

32

Low cut Picture / OCT live B scan image

34 35

line

36

Area of interest

Claims (18)

A method for examining the retina, wherein retinal surface images are generated, characterized in that second data and two-dimensional depth sectional images are generated from the retina and the position of these second data in the recorded area image of the retina is known and / or specified according to the surface image. Method according to claim 1, characterized in that that the position and / or orientation of one or more depth-sectional images based on the area image controlled and / or actively controlled and / or predetermined and / or that the position and / or the orientation of one or more depth-sectional images predefined and active on the basis of a previously recorded area image is controlled. Method according to claim 1 or 2, characterized that the position and / or the orientation of one or more depth-sectional images predetermined by a first recorded area image and a Updating the area image is actively controlled and / or that the movement of the updated surface image is determined relative to the first recorded area image and that the position of taking one or more depth-sectional images controlled at the predetermined locations and / or areas of the retina becomes. Method according to one of claims 1 to 3, characterized that the first area image or the updated area image and the depth sectional image simultaneously and / or simultaneously or in predeterminable, preferably small, time intervals by means of one or more Display units are displayed. Method according to one of claims 1 to 4, characterized that the depth sectional image stabilized by feedback such becomes that the place of the retina, at which the deep section picture is obtained, follows the eye movements and / or tracked. Method according to one of claims 1 to 5, characterized that of several consecutive, preferably stabilized Depth-sectional images an averaging is performed and / or that the or the averaged depth sectional images, in particular as sliding Mean value are displayed. Method according to one of claims 1 to 6, characterized that while stabilizing an automatic recording of several parallel to each other or according to one arbitrary and / or predetermined patterns and in predetermined intervals staggered depth sectional images take place and / or that of several successive depth sectional images a three-dimensional Depth sectional image is generated. Method according to one of claims 1 to 7, characterized that the positions of the depth sectional image and / or reference image be saved and that the further depth sectional image of a Follow-up examination in exactly the same place and / or with the same orientation as in a previous one Investigation and / or that the position of the further depth sectional image is stored. Method according to one of claims 1 to 8, characterized that the two-dimensional area image via reemit Light in one or more selected wavelength ranges is generated and / or that for recording or generating the area image the retina with light of a selected wavelength range or more selected ones Wavelength ranges is illuminated. Method according to one of claims 1 to 9, characterized that the lighting to capture the area image with a dot done, the grid-shaped scans the area and / or area of the retina and / or The lighting is done with a line that crosses the area or the area the retina becomes. Method according to one of claims 1 to 10, characterized that the detection by means of point detector or by means of a line camera or by means of a surface camera carried out becomes. Method according to one of claims 1 to 11, characterized that the inclusion of depth sectional images according to a Fourier Domain OCT method or after a time domain OCT procedure. Method according to one of claims 1 to 12, characterized that the two-dimensional surface image is an angiography image. Method according to one of claims 1 to 13, characterized that a first angiography image and a second two-dimensional image Retinal image and / or area image recorded simultaneously or at very short intervals and that the control and control of the recording of depth sectional images based on an update of the second area image. Method, in particular according to one of claims 1 to 14, characterized by the combination of areal angiography images and in particular simultaneous generation and / or presentation of the depth sectional images, especially OCT depth-sectional images. Device for examination of the retina, wherein first data and first area images the retina are generated, characterized by the training to carry out The method according to any one of claims 1 to 15. Apparatus according to claim 16, characterized ge indicates that a first system component ( 22 ), which is an image acquisition unit ( 4 ) and a scan control unit ( 10 ) for the area images, that a second system component ( 24 ) is provided, which a scanning unit ( 16 ) and a scan control ( 20 ) for generating the depth sectional images, and that the beam paths of the two system components ( 22 . 24 ) in a common optical unit ( 12 ), whereby the combined rays are directed to the eye to be examined and from there to the optical unit ( 12 ), by means of which a corresponding distribution to the first system component ( 22 ) or to the second system component ( 24 ) he follows. Apparatus according to claim 16 or 17, characterized by a common control and processing unit ( 14 ) for the two system components ( 22 . 24 ) and that to the control and processing unit ( 14 ) another unit ( 26 ), in particular for the purpose of operation and evaluation, and also a display unit ( 28 ) for the area images ( 30 ) as well as the depth sectional images ( 32 ) connected.