A device for examining the retina of the eyeball.

Abstract

The apparatus for examining the retina (10) of the eyeball (7) includes an OCT device (2) that acquires an OCT image (14) using optical coherence tomography (OCT), and another device (4) that acquires another image (13) of the retina (10), characterized in that a data processing unit (18) uniquely assigns the OCT image (14) to at least one image (13), and uses the structures (17) of the retina (10) detected by both the OCT image (14) and the other image (13) as calibration targets for the OCT device (2) and the other device (4).

Description

Technical Field

[0001] The present invention relates to an apparatus according to the generic concept of claim 1.

Background Art

[0002] The name, optical coherence tomography (in English “Optical Coherence Tomography”, usually abbreviated as OCT), is interpreted as an imaging method. Using this method, two-dimensional and three-dimensional images can be obtained from an optically scattering structure. In this method, light having a certain bandwidth is usually split into two partial light beams in a beam splitter. The first partial light beam is incident on a test sample or a reference object, and the second partial light beam passes through a reference section. The light reflected from the sample or object interferes with the reference light beam. The sample is inspected by a so-called A scan that resolves the sample in depth, that is, resolves the sample at a deep position on the optical axis of the first partial light beam, based on the signal from the interference. Further, the sample can be scanned in the plane direction or the lateral direction using the first partial light beam to obtain an OCT image. A B scan is composed of a plurality of A scans.

[0003] In the field of intraoperative OCT, it is very important that the OCT scanning position for obtaining an OCT image and, in particular, a microscopic image can be uniquely assigned to each other. This assignment is usually realized by a plurality of calibration targets or calibration marks that can be recognized in two modes or image classifications.

[0004] The two image classifications visualize the calibration targets and determine an appropriate coordinate transformation for adjusting the assignment of the scanning points for the OCT image to the image points for the microscopic image.

[0005] This calibration assumes that there are no additional optical elements acting on the two image classifications in various ways in the system. However, in the field of retinal imaging, it is quite common for such optical elements to exist.

[0006] To image the retina or the retina of the eyeball, an additional optical system (e.g., Oculus BIOM®) that achieves infinite image projection is directed into the optical path. The refractive elements of the eyeball under examination focus the light rays as much as possible onto the retina through the ocular optical system.

[0007] The OCT beam or OCT path is not collinear with the microscope's imaging path, resulting in a shift in image points between the two image classifications. This shift varies due to individual refraction in different eyeballs. Similar effects occur with surgical (OP) specific settings of additional optics, such as the focal point and relative position of the eyeball in the Oculus BIOM.

[0008] Furthermore, even when the aforementioned optical paths are on the same line, individual chromatic aberrations in the eyeball cause a shift in the image point on the retina. For these reasons, the image mapping system cannot be calibrated uniformly. Without individual calibration, judgment errors can occur during surgery (OP). [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] Therefore, the present invention refers to a device capable of generating both OCT images and other images, and the underlying problem is that these images capture or depict the same examination area as faithfully as possible without optical misalignment between them. [Means for solving the problem]

[0010] The present invention solves the above-mentioned problems with the features of claim 1.

[0011] According to the present invention, the oculoretinal examination apparatus includes an OCT device that acquires OCT images using optical coherence tomography, and another device that acquires images of the retina. Furthermore, according to the present invention, a data processing unit uniquely assigns the OCT images to at least one other image, and uses the structures of the retina detected by both the OCT images and the other image, which is a calibration target for the OCT device and the other device.

[0012] First, according to the present invention, it was found that there is a need to individually, preferably continuously, calibrate the OCT scanning position with respect to another image, such as a microscopic image, especially during surgery. In this regard, it was found that individual calibration can be performed using the above-described structure, and that this individual calibration can rewrite the general calibration in at least an instant. This ensures that the scanning position and the other image are displayed accurately. These images capture or reproduce the same examination area as faithfully as possible, without any optical misalignment between them.

[0013] According to the present invention, in particular, it has long been found that conventional intraoperative OCT systems do not adequately address the following problem: the issue of scanning positions within retinal regions that are not uniquely assigned to other images, i.e., microscopic images. Using the technical solutions described herein, OCT scans can be performed at precisely defined positions.

[0014] In this context, the data processing unit may match the scan coordinates of an OCT image to the corresponding pixel coordinates of another image, based on the positions of structures in the OCT image and another image. In this way, distinctive structures can be used as sophisticated calibration targets.

[0015] The data processing unit may use coordinate transformation to transfer the scan coordinates of an OCT image to the pixel coordinates of another image. This allows various images representing a single region to be arranged vertically or horizontally for analysis.

[0016] OCT images may be constructed as frontal images generated from OCT volumetric recordings of ocular tissue. In particular, during surgery, frontal OCT imaging, i.e., OCT cross-sectional images, can be recorded onto another image on a different device. This maps pixels to scanning coordinates. In this way, individual calibration can be performed particularly effectively. This individual calibration instantly overwrites the general calibration. This ensures accurate representation of the scanning position on another image.

[0017] The OCT volumetric record may be stored in data memory. In this way, the OCT volumetric record can be accessed at any time. The frontal image provides a cross-sectional view of the tissue. Acquiring a frontal image or frontal imaging takes a considerable amount of time depending on the size. Therefore, it is advantageous to use a particularly high-speed OCT system. In particular, an A-scan speed in the MHz range is preferred herein. Even more preferably, a particularly high-speed scanner and high-speed scan adjustment are used. For example, a closed scanning pattern such as a spiral can further increase scanning efficiency, so that in some cases recalibration can be performed almost continuously at regular intervals.

[0018] The data processing unit and / or control unit may align the scanning or detection position of the OCT image on the retina with, preferably simultaneously, the position of another image. Optical misalignment between the optical path of the OCT device and the optical path of another device is compensated for by additional optical components and / or the refractive behavior of the eyeball under examination. In this way, optics-mechanical effects can be compensated for electronically and therefore quickly.

[0019] The data processing unit and / or control unit may repeatedly match the scanning or detection position of the OCT image on the retina to the position and period of another image. In this way, the calibration can be adapted to changing imaging conditions. Since the device is automatically and / or autonomously recalibrated at predefined time intervals, it can reliably operate over long periods of time.

[0020] Visualization of OCT images is not required. Alternatively, or additionally, OCT images may be constructed as a set of image data. This allows only a separate image to be displayed for analysis, however, the OCT image data can be used solely for calibration purposes.

[0021] Another image may be used as the fundus image. Therefore, the other device may include an SLO (scanning laser ophthalmoscope) or a fundus camera.

[0022] Another device may be configured as a microscope, particularly as a surgical microscope, and another image may be configured as a microscope image. In this way, an extremely enlarged image of the retinal area can be created.

[0023] Posterior imaging using OCT within a surgical microscope is an important addition to existing OCT devices. In eye surgery, posterior surgery plays a major role, and high positional accuracy is specified for such surgery.

[0024] The device described herein may be used for highly accurate subretinal injection, particularly for treating retinal diseases in gene therapy. In this regard, it is essentially important that an OCT image or an OCT cross-sectional image can be aligned with an injection needle to observe the injection volume. This can reduce the dosage of extremely expensive drugs to be administered, which leads to significant cost savings.

[0025] The arrangement may include a device of the type described herein and additional optical components for examining the retina of the eye.

Brief Description of the Drawings

[0026] [Figure 1] FIG. 1 is a schematic diagram of the optical paths of an OCT device and a microscope. [Figure 2] FIG. 2 shows that the OCT optical path 1 of the OCT device 2 is not collinear with another device 4, specifically the imaging optical path 3 of a microscope in this specification. Due to this non-collinearity, a shift in image points 5, 6 occurs within the image classification between the OCT image 14 and another image 13, namely the microscope image.

Modes for Carrying Out the Invention

[0027] FIG. 1 shows that the OCT optical path 1 of the OCT device 2 is not on the same line as another device 4, specifically the imaging optical path 3 of a microscope in this specification. Due to this non-collinearity, a shift in image points 5, 6 occurs within the image classification between the OCT image 14 and another image 13, namely the microscope image.

[0028] This discrepancy is caused in particular by the individual refraction of the eyeball 7, especially its lens 8.

[0029] The surgical-specific settings of the additional optical system, namely the focal position of the magnifying glass 9 and the relative position of the eyeball, have a different effect.

[0030] Furthermore, even assuming that the two optical paths 1 and 3 are on the same line, individual chromatic aberrations in the eyeball 7 cause the image points 5 and 6 on the retina 10 to shift.

[0031] This device, which includes the OCT device 2 and a microscope, is assigned a front lens 11 and a reduction lens 12.

[0032] Figure 1 schematically shows a device for examining the retina 10 of the eyeball 7. The device includes an OCT device 2 that acquires an OCT image 14 using optical coherence tomography (OCT), and another device 4 that acquires another image 13 of the retina 10.

[0033] Figure 2 shows the image described above. Another device 4 is configured as a microscope, specifically a surgical microscope, and another image 13 is configured as a microscopic image.

[0034] Figure 2 schematically illustrates that, in addition to a series of microscope images 13, an OCT stereoscopic image is acquired only once, and an OCT image 14, i.e., a frontal image, is generated from that stereoscopic image. The OCT image 14 is configured as a frontal image generated from an OCT volume recording of the tissue of the eyeball 7. The OCT volume recording is stored in data memory. This OCT image 14 is not necessarily used for visualization, but is preferably, or exclusively, used for recording 15. For this reason, the OCT image 14 is preferably not visualized and is configured as a set of image data.

[0035] In the frontal image, a structure 17 identical to that in the microscope image 13 appears in part. This structure makes it usable in recording 15. The transformation of images 13 and 14 can be found and used using a well-known recording method. This transformation matches the structure 17 of the two image classifications.

[0036] This conversion is not only valid for frontal images, but generally represents the conversion of scanning coordinates to the corresponding pixel coordinates of the microscope. This opens up options for how to perform a B-scan accurately, or how to perform a B-scan, either within or based on the microscope image.

[0037] Therefore, Figures 1 and 2 schematically show that the data processing unit 18 uniquely assigns the OCT image 14 to at least one image 13, and uses the structures 17 of the retina 10 detected by both the OCT image 14 and the image 13 as calibration targets for the OCT device 2 and another device 4.

[0038] The data processing unit 18 matches the scan coordinates of the OCT image 14 to the corresponding pixel coordinates of the image 13, based on the positions of the structures 17 in the images 13 and 14.

[0039] The data processing unit 18 performs a coordinate transformation to transfer the scan coordinates of the OCT image 14 and the pixel coordinates of the image 13 relative to each other.

[0040] The data processing unit 18 and the control device 19 preferably simultaneously match the scanning or detection position of the OCT image 14 on the retina 10 with the position of the image 13, so that any optical misalignment between the optical path 1 of the OCT device 2 and the optical path 3 of another device 4 is compensated for by additional optical components and / or the refractive behavior of the eyeball under examination 7.

[0041] The data processing unit 18 and the control unit 19 periodically and repeatedly match the scanning position or detection position of the OCT image 14 on the retina 10 with the position of the image 13, thereby adjusting the calibration to the changing imaging conditions.

[0042] Figure 1 further shows an arrangement of the type of apparatus described herein, including additional optical components for examining the retina 10 of the eyeball 7. These additional components include a magnifying glass 9, an anterior lens 11, and a reducing lens 12. [Explanation of symbols]

[0043] 1 OCT light path 2 OCT device 3. 4. Mirror path 4. Another apparatus, specifically a microscope in this specification. 5 1 image point 6 3 image points 7 Eyeball 8. Eye Lens 9 Magnifying glass 10 Retina or retina (Latin) 11 Front lens 12 Reduction lens 13 Another image, specifically a microscopic image in this specification. 14. OCT image or frontal image 15 Records 16 conversions 17 10 structures

Claims

1. An apparatus for examining the retina (10) of an eyeball (7), comprising an OCT device (2) that records an OCT image (14) by optical coherence tomography (OCT), and another device (4) that records another image (13) of the retina (10), The apparatus is characterized in that a data processing unit (18) uniquely assigns an OCT image (14) to at least one other image (13), and uses the retinal structure (17) captured in both the OCT image (14) and the other image (13) as a calibration target for the OCT device (2) and the other device (4).

2. The apparatus according to claim 1, characterized in that the data processing unit (18) corresponds the scanning coordinates of the OCT image (14) to the corresponding pixel coordinates of the other image (13) based on the position of the structure (17) in the images (13, 14).

3. The apparatus according to claim 1 or 2, characterized in that the data processing unit (18) maps the scan coordinates of the OCT image (14) and the pixel coordinates of the other image (13) onto each other by coordinate transformation.

4. The apparatus according to any one of claims 1 to 3, characterized in that the OCT image (14) is configured as a frontal image generated from an OCT volume recording of the tissue of the eyeball (7).

5. The apparatus according to claim 4, characterized in that the OCT volume record is stored in a data memory.

6. The apparatus according to any one of claims 1 to 5, characterized in that the data processing unit (18) and / or control device (19) preferably simultaneously correspond the scanning position or imaging position of the OCT image (14) on the retina (10) to the operation position or imaging position of the other image (13), and the optical offset between the optical path (1) from the OCT device (2) and the optical path (3) from the other device (4) is compensated by additional optical components and / or the refractive behavior of the eyeball under examination (7).

7. The apparatus according to any one of claims 1 to 6, characterized in that the data processing unit (18) and / or control unit (19) periodically and repeatedly associate the scanning position or imaging position of the OCT image (14) on the retina (10) with the scanning position or imaging position of the other image (13), and the calibration is adapted to the changing recording conditions.

8. The apparatus according to any one of claims 1 to 7, characterized in that the OCT image (14) is not visualized and / or is configured as an image dataset.

9. The apparatus according to any one of claims 1 to 6, characterized in that the other device (4) is configured as a microscope, and the other image (13) is configured as a microscope image.

10. An arrangement comprising the apparatus according to any one of claims 1 to 9, and an additional optical component for examining the retina (10) of the eyeball (7).

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