WO2013041521A1

WO2013041521A1 - Methods and devices for examining eyes

Info

Publication number: WO2013041521A1
Application number: PCT/EP2012/068342
Authority: WO
Inventors: Michael Kempe; Tobias Schmitt-Manderbach; Thomas Mohr; Gerhard Krampert
Original assignee: Carl Zeiss Ag; Carl Zeiss Meditec Ag
Priority date: 2011-09-20
Filing date: 2012-09-18
Publication date: 2013-03-28
Also published as: DE102011053777A1

Abstract

Methods and devices for examining eyes are disclosed, said devices having a camera unit (103) and a laser scanner unit (102). The laser scanner unit (102) can be set by a controller (104) in accordance with an image captured by the camera unit (103).

Description

Methods and devices for eye examination

The present invention relates to methods and devices for eye examination with optical means, for example for performing fluorescence measurements in the eye. For the diagnosis of diseases of a retina of an eye, in particular of a human eye, it is known to use so-called fundus cameras (fundus is called the ocular fundus) or laser scanners in combination with fluorescence and autofluorescence techniques. Such methods and devices are known, for example, from DE 10 2008 01 1 836 A1, DE 10 2007 061 987 A1 or WO 201 1/038892 A1.

In general, excitation light is radiated into the eye to excite fluorescence either from previously introduced probes, also referred to as markers, or from naturally occurring molecules in the eye, and then to detect the fluorescence light. By a spectrally resolved detection as described for example in DE 10 222 779, for example, the fluorescence of various molecules present can be separated from each other.

One type of laser scanners used in this case are so-called confocal laser scanning ophthalmoscopes (cSLO, from English "Confocal Laser Scanning Ophthalmoscope") in which for fluorescence measurements a serial, ie scanning, point-like excitation of a region of interest and located in the area fluorescent objects, such as molecules, The field thus excited in a punctiform manner is then confocally imaged into a field stop which is arranged in front of a detector, in particular a single detector, and then a two-dimensional image can be built up from the measurements for the individual points by means of the confocal principle used in such constructions In the case of such a cSLO, for example, a spectrally resolved detection can be achieved by spectral resolution of the light and simultaneous detection in several channels len, as it is also used in laser scanning microscopes. In the use of specific binding, exogenous fluorescent probes (hereinafter simply called probes), ie substances, in particular molecules, which are supplied to a patient and which bind to substances to be detected in the body of the patient, the problem arises that the fluorescence of the at Detected substance bound probes must be distinguished from the fluorescence of unbound probes. One possibility for this is the determination of the fluorescence lifetime (fluorescence lifetime microscopy, abbreviation FLIM) and / or the spectral fluorescence distribution, since in many probes the spectral fluorescence distribution and / or the fluorescence lifetime changes as a function of the binding to the substance to be detected For example, a shift in the spectral characteristic or a change in the fluorescence lifetime upon binding of the probes to the substance to be detected is used to differentiate., For example, a time-correlated single photon count is used to determine the fluorescence lifetime, as described in DE 199 20 158 and DE 10 145 823 is described.

CSLO imaging, particularly when using fluorescence lifetime measurements, is very slow due to sequential image formation during scanning, and particularly weak signals typical of fluorescence measurements in the eye. A large-area imaging of, for example, the retina is therefore very time-consuming, unpleasant to unacceptable for the patient or even impossible in many patients.

It is therefore an object of the present invention to provide devices and methods for eye examination, which allow a more efficient examination.

This object is achieved by a method according to claim 1 and an apparatus according to claim 11. The subclaims define further embodiments.

There is provided an eye exam device comprising:

a camera device for taking an image of a part of an eye to be examined,

a laser scanner device for scanning at least a portion of an eye with a laser beam and with a detection device for detecting light emitted by the eye in response to the scanning, and

a control device, which is set up to adjust the laser scanner device in dependence on the image taken by the camera device. In such a device, a detailed morphological image or with a fluorescence imaging or by spectroscopic methods (such as multispectral reflection or fluorescence imaging as well as Raman microspectroscopy) can very quickly be used, for example by means of color imaging, by the camera device, for example a so-called fundus camera for taking an image of the ocular fundus ) a functional overview image of the part of interest of the eye can be created, and by the adjustment of the laser scanner in response to this image, the laser scanner can be used efficiently, in particular so as to reduce a required measurement time. For example, regions of interest in the overview image can be defined or found by image analysis, for example regions in which a fluorescence to be detected occurs or is above a predetermined threshold, and by means of the laser scanner device only those regions of interest are examined by an appropriate setting. Also, parameters of the laser scanner, for example laser power, detector gain or a scanning speed, can be set as a function of the overview image. It is also possible, for example, to set a confocal suppression in the beam path of the laser scanner on the basis of the camera image, for example as a function of a contrast of the camera image. The laser scanner device may in particular be a confocal laser scanning ophthalmoscope.

The camera device and the laser scanner device can at least partially have a common optic, for example a common ophthalmoscope lens, ie a part of the optic which is closest to the eye to be examined. In this case, for example, beam splitters can be used to merge or separate a beam path of the laser scanner device and a beam path of the camera device. A camera image provided by the camera device can also be used for positioning the device relative to the eye to be examined and / or for tracking such a positioning. For this purpose, the camera device can have an infrared camera. The device may additionally comprise an optical coherence tomography (OCT) device. The laser scanner device can then additionally depending on optical coherence tomography are adjusted, for example by focusing.

In a corresponding method, an image of a part of an eye to be examined is recorded by a camera device, a laser scanner device is set as a function of the image and at least a section of the eye is scanned with the laser scanner device, in response to the section scanned by the laser scanner device an illumination with the laser of the laser scanner outgoing light is detected. Such a method can be carried out, for example, with the devices described above.

The invention will be explained in more detail with reference to the accompanying drawings with reference to embodiments. 1 is a block diagram of a first embodiment of a device according to the invention,

2 is a schematic of a second embodiment of a device according to the invention,

3 is a schematic of a third embodiment of a device according to the invention,

4 is a schematic of a fourth embodiment of a device according to the invention,

5 is a schematic of a fifth embodiment of a device according to the invention, Fig. 6 is a schematic of a sixth embodiment of a device according to the invention and

7 shows a flow chart of an exemplary embodiment of a method according to the invention. In the following, embodiments of the present invention will be explained in more detail. It should be noted that features of various embodiments may be combined with each other unless otherwise specified. On the other side is one A description of an embodiment having a plurality of features is not to be construed as requiring all of these features for practicing the invention, as other embodiments may have fewer features and / or alternative features.

In the figures, similar elements are denoted by the same reference numerals. It should be noted that these elements are not necessarily identical, but the same reference number indicates that the corresponding elements perform substantially the same function. The exemplary embodiments described below relate to devices and methods for eye examination, in particular for ophthalmoscopy (ophthalmoscopy). As described below, an eye, in particular a human eye, is illuminated, in particular the inside of the eye or the fundus (fundus oculi) illuminated through the pupil, and light emitted from the inside of the eye is detected.

A first embodiment of a device according to the invention is shown in FIG. The device of FIG. 1 is used to examine an eye 100, for example of a human eye, and comprises a laser scanner device 102 and a camera device 103. For coupling light from the laser scanner device 102 and the camera device 103 into the eye 100, the device of FIG FIG. 1 shows an ophthalmoscopic lens 101, ie a lens which is dimensioned for coupling light into the eye 100 and for collecting light emanating from the eye 100, and which may consist of only a single lens. In particular, an overview image of the ocular fundus of the eye 100 or a part thereof can be taken with the camera device 103, for example a color image and / or an infrared image. If images are to be recorded by the camera device in different spectral ranges, for example in the visible region or parts thereof or in the infrared, corresponding filters and possibly several cameras in the camera device 103 can be provided for this purpose. The camera device 103 can also have illumination for illuminating the eye 100.

The laser scanner device 102 comprises at least one laser light source and is set up, for example by means of a movable mirror, to scan a region of interest of the eye 100, for example the fundus or a part thereof. By means of the laser light, for example, fluorescence can then be excited, which in turn is detected by means of a detector device of the laser scanner device 102 can. The laser scanner device 102 may in particular be designed as a confocal laser scanner ophthalmoscope (cSLO) and may optionally also be designed for optical coherence tomography (OCT). The device of FIG. 1 also has a controller 104, for example in the form of a computer, which is coupled to the camera device 103 and the laser scanner device 102. The controller 104 has an input device 105, such as a keyboard and mouse, and a screen 106 through which information for an operator of the device can be displayed. Via the input device 105, an operator can control the device of FIG.

The controller 104 of the device of FIG. 1 is in particular configured to control the laser scanner device 102 on the basis of images taken by the camera device 103. This activation can take place fully automatically, for example by using an image analysis of the images supplied by the camera device 103, or semi-automatically, ie with the possibility for an operator to intervene in the adjustment. In the case of a partial automatic, for example, information obtained from the images of the camera device 103 can be displayed on the screen 106, which in turn allows an operator to influence the setting of the laser scanner device 102 via the input 105. For example, in fluorescence measurements with the camera 103, an overview image of the ocular fundus may be taken, and the controller 104 may then identify user-assisted areas of interest (ROI), for example, areas where the fluorescence to be examined occurs These regions of interest may then be examined with the laser scanner device 102, for example with high spatial resolution and / or spectral resolution, and parameters of the laser scanner device 102, for example a laser power, a detector gain or a scan speed , are adjusted in response to an image taken with the camera device 103 by the controller 104. Also, a confocal suppression, for example, a size of a pinhole, may be based on a Bi of the camera device 103, for example a contrast of the image. In addition, there are settings which can be carried out jointly for the camera device 103 and the laser scanner device 102, for example a setting for compensating for ametropia of the eye 100 to be examined or a focus adjustment. Such a combination of camera device 103 and laser scanner device 102 via the controller 104 is particularly advantageous because laser scanner devices 102 for eye examination usually use selected lasers in the blue / green spectral range and / or infrared laser and thus can not provide color information, which in turn is provided by the camera device 103 can. The image recorded by the camera device 103 makes it possible, in particular in some embodiments by image analysis in the controller 104, to determine or estimate a reflectivity of a retina of the eye 100 to be examined and to set the laser scanner 102 accordingly. In addition, image acquisition by the camera device 103, in particular a flash photography, is usually made faster than scanning a larger region, for example of the ocular fundus of the eye 100, so that the use of an image of the camera device 103 reduces the occurrence of artifacts due to eye movements. In the case of camera devices 103, which optionally also continuously record an infrared image, this can be used, for example, to control the positioning of a patient with the eye 100.

Referring now to FIGS. 2-6, more detailed embodiments are shown which may be considered as examples of the implementation of the apparatus of FIG. In Figs. 2-6, no control is shown for simplicity, such a control as described above with reference to Fig. 1, optionally with an input device and a screen, may also be provided in the embodiments of Figs. 2-6 ,

As a laser scanner device, the embodiment of FIG. 2 comprises a confocal laser scanning ophthalmoscope (cSLO), which one or more laser light sources 1, which are coupled to a housing head 41 via optical fibers, in particular preferably polarization-maintaining single-mode fibers 2, as well as a detection device 15, which is coupled to the housing head 41 via a light guide, in particular a multimode fiber 14. In particular, two laser light sources 1 are shown in FIG. 2, which, for example, can emit light of different wavelengths, in particular infrared light. In this case, the laser light sources and the wavelengths associated therewith can be selected as a function of an examination to be carried out with the device, for example in accordance with an excitation wavelength of a fluorescence to be detected. The light emitted by the light guides 2 is collimated by means of collimator lenses 3, respectively. 4 generally designates mirrors for beam deflection. Via a dichroic beam splitter 29, the light of the laser light sources 2 is superimposed. Another dichroic beam splitter 30 is used for the separation of illumination and detection beam path as will be explained in more detail below.

In particular, the excitation light generated by the laser light sources 1 is directed by the dichroic beamsplitter 30 to a scanner mirror 5 which is movable to allow scanning of a region of interest with the laser beam. The scanner mirror 5 may comprise, for example, a single biaxial mirror or a combination of two uniaxial mirrors. The scanner mirror 5 is arranged in the embodiment of FIG. 2 in a conjugated pupil plane of the optical system. The scanner mirror 5 in the exemplary embodiments illustrated preferably comprises one or more non-resonant scanner mirrors, so that any regions of the eye 10, in particular regions which were selected on the basis of an image of the camera device 40 as described below, can be scanned at an adjustable speed, since in this way the resolution and signal-to-noise ratio can be optimized without increasing a light load on the eye. In this way, a speed advantage over a complete scanning of an ocular fundus can be achieved with a laser scanner device.

The laser light is directed to the eye 10 via a beam splitter 8 and an ophthalmoscope lens 9 via two objectives 6, 7, the objective 6 serving as the scanning objective and the objective 7 as the field objective. In this case, the objective 6 and / or the objective 7 can have movable lenses or movable lens groups in order to focus the laser light on a layer of the fundus to be examined, for example on a location of the retina of the eye 10 to be examined. In other embodiments, the arrangement may have a fixed focus, and the eye 10 is placed accordingly. In some embodiments, the beam splitter 8 may be movable between the position in the beam path (shown in FIG. 2) and a position outside the beam path to switch between a scan with the laser scanner and an image capture with a camera device 40 described below. The position of the beam splitter 8 can be determined accordingly by calibration, so that the camera device 40 and the laser scanner device between the beam splitter 8 and the eye 10 have substantially the same beam path. In other embodiments, the beam splitter 8 may also be permanently installed and be wavelength-selective, for example, so that it is at least partially reflective for the light used by the laser scanning device and at least partially transparent to the light used by the camera device 40. With the laser light of the laser light sources 1 directed into the eye 10, it is possible, for example, to excite substances in the eye 10, for example probes or endogenous substances, or to modify the light in another way, for example by scattering.

The light emanating from the eye 10, in particular the fundus, for example the retina, in response to the laser light, for example scattered light or fluorescent light, passes via the ophthalmoscope lens 9, the beam splitter 8, the objectives 6 and 7 and the mirror 5 again to the beam splitter 30, which is at least partially transparent for wavelengths of interest, so that at least a part of this light is further focused on a pinhole 12 via a pinhole lens 1 1. The pinhole 12 has a variable size, so that a signal strength at the detector device 15 and a confocality can be adjusted. Finally, the light passing through the pinhole 12 is coupled into the light guide 14 via a lens 13 and thus reaches the detection device 15. The detection device 15 can be set up in particular for spectrally resolved detection and / or temporally resolved detection.

Next, the camera device 40 will be described in detail. The camera device 40 comprises a lighting 16, which may in particular comprise at least one broadband emitting source. For example, the illumination 16 may comprise a flashlamp, one or more white light diodes, or a combination of different colored light emitting diodes. By way of a collimator 17, a field objective 18, a ring diaphragm objective 20 and an objective 22, which can be designed, for example, to be anti-reflexive, for suppression of reflections, the light passes from the illumination 16 to a beam splitter configured as a perforated mirror the light which does not fall on the hole of the beam splitter 23, directs to the ophthalmoscope lens 9 and finally to the eye 10. Light emitted from the illumination 16 by the eye 10 in response to light passes through the ophthalmoscope lens 9 through the hole of the beam splitter 23 to an objective 24.

Between the field objective 18 and the ring diaphragm objective 20, a retinal aperture 19 is provided, and between the ring diaphragm objective 20 and the objective 22 a ring diaphragm 21 is provided. In addition, a preferably exchangeable color filter 31 can be provided in order to select desired wavelengths of the light emanating from the illumination 16, for example wavelengths tuned to an excitation wavelength of a fluorescence to be examined. Of the lens 24, which may have one or more movable lenses or lens groups for focusing, the light passes to a beam splitter 28 and from there via a likewise preferably changeable color filter 32 and a camera lens 25 to a camera 27, for example a CCD camera or CMOS camera. With the color filter 32, a wavelength range of interest, for example, corresponding to a wavelength of a fluorescence to be detected, can be selected so as to filter out unwanted light, eg, reflected light. In addition, light passing through the beam splitter 28 can pass through a camera lens 25 to another camera 26, which may likewise be a CCD camera or a CMOS camera. In particular, the beam splitter 28 can be set up to direct light in the visible range wholly or largely to the camera 27, which can then serve, for example, for recording color images, and guide light in the infrared spectral range completely or partially to the further camera, which is particularly suitable for Recordings in the infrared can be set up. As already mentioned, based on an image of the camera device 40, for example an image taken by the camera 27, the laser scanner device can be adjusted. For example, a focusing of the objectives 6, 7 can be carried out in synchronism with a focusing of the objective 24, wherein the focusing of the objective 24 on the basis of an image of the camera 27 can take place. Furthermore, as already explained with reference to FIG. 1, parameters of the laser scanner device can be adjusted on the basis of an image of the camera 27 and / or the camera 26, or regions of interest can be defined, which are then moved by means of a corresponding movement of the scanner mirror 5 be scanned. A size of the pinhole 12 can be adjusted on the basis of a recorded camera image of the camera 27, in particular on the basis of a contrast camera image, for example in the case of strong cataracts.

On the basis of a recorded image, in particular a reflection image, eye movements between individual measurements, in particular of the laser scanner device, can also be compensated.

The housing head 41 and the camera device 40 may be designed as individual modules, which can be coupled, for example, by plugging together or by screws.

It should be noted that the embodiment of FIG. 2 merely shows one possible implementation of a combination of laser scanner device and camera device, and a large number of variations are possible. For example, in some embodiments, the camera device 40 includes only a single camera or more than two cameras. It should also be noted that all of the illustrated lenses and lenses, although shown generally as a single lens in FIG. 2, may include one or more lenses and / or one or more sets of lenses. Further modifications of the embodiment of Fig. 2 will be explained below with reference to Figs. 3-6. FIG. 3 shows an exemplary embodiment of a device according to the invention, which is designed in addition to the functionalities of the embodiment of FIG. 2 for optical coherence tomography (OCT). For this purpose, an OCT module 42 can be coupled to the housing head 41. Laser light of a wavelength between 800 and 1100 nm is typically used to perform OCT measurements, which is generated in the embodiment of FIG. 3 by at least one of the laser light sources 1. The beam splitter 30 is at least partially transmissive for light of this wavelength, so that part of the light from the laser light source 1 is not directed to the scanner mirror 5, but coupled via a focusing lens 33 in a Lichtlei- ter, in particular a single-mode fiber 35 with polarization control becomes. Such a polarization control can be carried out by means of fiber loops, for example, by changing a birefringence of stress in the fiber, in order to optimize a signal used for the OCT. In other words, the polarization control can change the polarization of the light passing through the fiber 35.

The light emerging from the fiber 35 is collimated by a lens 34 and reflected by a retroreflector 36, whereby the beam path can be folded by mirror 4 to achieve a more compact arrangement. The beam path from the beam splitter 30 to the retroreflector 36 should have the same optical path length for the measurement as the beam path from the beam splitter 30 to the part of the eye 10 to be measured, for example the ocular fundus. In order to allow a fine-tuning here, the retroreflector 36 is preferably designed to be displaceable. Furthermore, both beam paths preferably have at least approximately the same dispersion, which can be achieved by a corresponding design of the fiber 35. Thus, a reference beam path is provided by the OCT module 42, whereby the reference beam, after reflection at the retroreflector 36, again passes through the lens 34 and the fiber 35 and the lens 33 to the beam splitter 30 and then through the lens 1 1, the pinhole 12 and the lens 13 finally reaches the detection device 15 and can interfere with the light coming from the eye 10.

It should be noted that with such an arrangement, the function of a cSLO and an OCT can be realized in parallel, but it is also possible, in particular the laser light sources 1 and the detection device 15 only to perform OCT measurements.

Another embodiment is shown in Fig. 4. Compared to the exemplary embodiment of FIG. 2, the coupling between laser scanner device and camera device 40 is changed. In particular, the positions of beam splitter 8 and beam splitter 23 are reversed or, in other words, the beam splitter 8 is arranged from the viewpoint of the laser scanner device, in particular the housing head 41, in front of the beam splitter 23 designed as a perforated mirror. Compared with the embodiment of FIG. 2, interference in the embodiment of FIG. 4 can be more easily avoided. On the other hand, the usable pupil of the laser scanner device is limited by the beam splitter 23 designed as a perforated mirror. Otherwise, the embodiment of FIG. 4 corresponds to the embodiment of FIG. 2. A further modification is shown in FIG. Compared with the embodiment of FIG. 4, the position of the beam splitter 8 is now between the objective 24 and the beam splitter 28, and the objective 7 is omitted. In the exemplary embodiment of FIG. 5, the focusing of both the laser scanner device and the camera device can thus take place together via the objective 24.

FIG. 6 shows a further modification of the exemplary embodiment of FIG. 2, in which, in particular, the beam path in the housing head 41 has been changed. In particular, in the embodiment of FIG. 6, two so-called 4f arrangements are provided with identical lenses 37, whereby the conjugate pupil plane of the arrangement is made accessible. In this conjugate pupil plane there is an element 38, which may be a ring stop, for example, as shown, but in other embodiments may also be a phase element for generating a point spread function (PSF) with axial extension, for example a bessel Beam which can be generated by a phase element with an axicon-like phase function, as known from the prior art In the corresponding conjugate pupil plane in the detection beam path, a shutter 39 is arranged, which effectively limits a pupil size.

As already mentioned, various embodiments can be combined. For example, the OCT module 42 may also be provided in the embodiments of FIGS. 4, 5 and 6. As already mentioned, devices according to the invention are preferably of modular construction, so that the camera device 40, the housing Head 41 and the OCT module 42 can be combined as needed. For example, in this way the camera device 40 can also be used alone, the camera device 40 can be combined with the housing head 41, or the camera device 40 can be combined with the housing head 41 and the OCT module 42 so as to provide an OCT functionality or both. Provide functionality and OCT functionality.

In devices such as those shown for eye examination, reflections within the beam path can impair the quality of the images taken by the camera device 40 and / or the laser scanner device. In order to reduce such reflections, for example, the objective 22, the beam splitter 8 and the ophthalmoscope lens 9, but also other elements, can be provided with reflection-reducing optical layers. Also, beam traps may be arranged for reflections coming from the objective 22, the beam splitter 8, the ophthalmoscope lens 9 or other elements. In addition, in some embodiments, an antireflective ophthalmoscope lens 9 can be used.

In addition, transitions between different media of the eye itself, such as cornea (cornea), anterior chamber or lens, can lead to unwanted reflections. In the case of the camera device 40, for example, a complete separation of the illumination and detection beam path can be carried out to avoid the detection of such reflections, as is realized in the exemplary embodiments of FIGS. 2-6 by the beam splitter 23 designed as a perforated mirror, whereby the detection beam is produced. In embodiments of the invention, in addition, a broadband correction of the detection beam path in the laser scanner device can be carried out, so that the smallest possible longitudinal chromatic aberration and lateral chromatic aberration occur, in particular in the confocal observation diaphragm Eye, especially in the transition between different media of the eye, as well as reflections on optical elements in the laser scanner device is to suppress, by appropriate choice of the size of the pinhole 12, in particular a small s pinhole, to achieve a correspondingly high confocal suppression, ie signals which are not generated in the focal plane are suppressed. However, this leads to a depth range in the eye, from which a signal is actually detected (also referred to as confocal slice width) which is smaller than a depth of field of the camera device, since at least the embodiments shown in FIGS. Examples, the effective pupil of the laser scanner device is greater than the detection pupil of the camera device. In order to compensate for this difference between the confocal slice width and the depth of field of the camera device and thus the images taken by these, in some embodiments during the scanning with the laser scanner device in addition to a scanning in a lateral direction, ie on a surface to be examined, an axial scanning, ie in the depth direction. In other words, the focal plane is additionally changed. This can be done, for example, by an oscillating movement of the objective 7 along the optical axis. In other words, several measurements are carried out with different focal planes, which are then offset with one another (eg for a maximum-intensity projection). In other embodiments, additionally or alternatively, a confocal imaging of the laser scanner device with extended depth of field can take place (EDoF, "Extended Depth of Field"), which can be achieved, for example, with the device of Fig. 6. For this purpose, the elements 38 and 39 can also be variable , For example, have variable openings so as to be adapted to a particular measurement strategy and / or a patient can.

In addition, in some embodiments, an illumination beam path of the laser scanner device used can be adapted to a size of a pupil of the eye to be examined, for example the eye 10, in order to couple as much light into the eye as possible, but not to illuminate the iris of the eye. This can be achieved, for example, by providing a zoom lens in the beam path of the laser scanner device, for example between the beam splitter 29 and the beam splitter 30, preferably between the beam splitter 29 and the mirror 4 lying between the beam splitter 29 and the beam splitter 30.

As already partially explained above, in embodiments of the invention, measures can be taken to avoid measurement artifacts due to movement of the eye to be examined or due to unfavorable positioning of the measuring device. In particular, continuous imaging in the infrared can be used here, for example by means of the camera 26, in order to image movements of the fundus of the eye. Based on this data, a positioning of the laser beam can be coupled with an automatic tracking in order to automatically compensate for movements of the eye to be examined. The recorded movement data can also be used for a subsequent correction of the data obtained with the laser scanner. To optimize a quality of the recorded data and optical errors of the eye to be examined by the optics used, for example, the lenses and lenses shown, can be compensated. For example, a focusing aid can be provided in the laser scanner device, which optionally can compensate for astigmatism. Higher order errors in the eye to be examined can be compensated by means of adaptive optics located in a conjugate pupil plane of the laser scanner.

In the embodiment of FIG. 3, focusing of, for example, the objective 7 on the basis of so-called A-scans can be carried out by means of the OCT device 42.

It should be noted that in the embodiments of FIGS. 2-6 instead of the coupling of the laser light sources 1 through the light guide 2, a free-beam optics can be used. In the same way, instead of the coupling of the detection device 15 via the light guide 14, the detection device 15 may be provided, for example, directly in the measuring head 41. The pinhole 12 may be a variable or a fixed pinhole. Various optical elements can also be combined, for example, the objectives 6 and 7 can also be designed as a single lens.

FIG. 7 shows a flowchart for illustrating an embodiment of a method according to the invention. For example, the method of FIG. 7 may be implemented in the devices of FIGS. 1-6, but may be used independently thereof.

In step 50, an overview image of an eye fundus or a part thereof is taken with a camera device. In other embodiments, other portions of an eye may be included. For this purpose, it is possible, in particular, to use an illumination which is adapted to an excitation wavelength of a fluorescence to be detected, for example by means of one or more filters, and a detection with a corresponding camera such as the camera 27 can be adapted by means of a filter to a wavelength of a fluorescence to be detected. In addition or alternatively, a color image can also be recorded. In step 51, a laser scanner, for example a cSLO, is set as a function of an analysis of the overview image. For example, regions of interest can be determined on the overview image, for example regions in which fluorescence is emitted. occurs, and the areas of interest can be defined accordingly. The laser scanner can then be set to scan only the areas of interest. Also, as already explained, parameters of the laser scanner can be set as a function of the overview image.

In step 52, the ocular fundus is then scanned with the laser scanner, for example the areas of interest set in step 51, and parallel to this, in step 53, detection of light emanating from the eye in response to the scanning, in particular fluorescent light. The detection can be a pixel-wise spectral detection on at least two channels. On the basis of this detection, it is possible to carry out a segmentation of structures which have predetermined features, for example with regard to their shape, brightness or their spectral properties. In particular, spectral properties can be typical properties of a probe to be detected and, in addition to the fluorescent light, can also be obtained from the light, in particular inelastically backscattered light (multispectral imaging and Raman microspectroscopy). On the basis of this segmentation of structures, smaller areas can be defined within the areas of interest, and in these areas additionally a lifetime determination of a fluorescence, for example by time-resolved detection, can take place in such areas and possibly adjacent areas. In other embodiments, such lifetime measurements may also be made in the entire areas of interest. In addition to or instead of the lifetime measurements, a three-dimensional OCT image can also be taken in the area of interest, for example a registered three-dimensional OCT image, for example using the exemplary embodiment of FIG. 3.

The data thus acquired by means of the detection 53 and the overview image can then be analyzed and, if appropriate, compared with data from previous examinations on the same patient or a database with data to be regarded as "normal." In such an analysis, in particular the size and structure of fluorescent regions , spectral signatures and fluorescence lifetime in such regions relative to the environment, assignment to layers of the ocular fundus from lifetime data and / or comparison with retinal morphology, and a total distribution of fluorescent regions in the ocular fundus, e.g. Retina, for example, can be used to detect diseases. During the execution of the method of FIG. 7, as already discussed, a movement of an eye to be examined, for example triggered by patient movements, can be detected and taken into account during the measurement, for example by tracking the measuring device. Alternatively or additionally, the data obtained can be subsequently corrected for corresponding movements.

As already mentioned, the adjustment in step 51 may also include an adjustment of parameters of the laser scanner device such as laser power, detector gain and scan speed. For this purpose, for example, a database or a look-up table can be used, which supplies such values as a function of a brightness and a contrast of the overview image. Focusing can also be carried out jointly for a camera device and a laser scanner device, for example by setting the lenses 17 and 24 synchronously in the embodiment of FIG. 2. A size of a pinhole, such as the pinhole 12, can also be derived automatically from a contrast of the acquired overview image, in particular if the overview image is displayed in a same contrast mode, i. was tuned to the same probes as the scanning was done with the laser. In some embodiments, such a possibility of adjusting the pinhole and thus the confocality of the laser scanner can also be used to achieve a simpler registration and color matching of an overview image taken with a camera device and a laser scan recorded with the laser scanner device. A high contrast, high depth discrimination image can then be printed with a much smaller pinhole size, i. strong confocality.

Claims

P AT EN TA NSPR O CHE

1 . Eye examination method comprising:

Taking an image of at least a part of an eye (10; 100) with a camera device (103; 40),

Setting a laser scanner device (102, 41, 42, 14, 15, 1, 2) in dependence on the recorded image,

Scanning at least a portion of the eye (10; 100) with the laser scanner device (102; 41, 42, 14, 15, 1, 2), and

Detecting light emitted from the scanned portion in response to the scanning. 2. The method according to claim 1, wherein adjusting the laser scanner device (102; 41, 42, 14, 15, 1,

2) depending on the image comprises determining the at least one section in dependence on the image.

3. The method of claim 2, wherein detecting comprises detecting fluorescent light, and

wherein determining the at least one portion in response to the image comprises determining fluorescent areas in the image.

4. The method of claim 3, wherein detecting comprises detecting stray light, and

wherein determining the at least one portion in response to the image comprises determining regions in the scattered light image.

The method of any one of claims 1-4, wherein adjusting the laser scanner in response to the image comprises adjusting at least one scan parameter in response to the image.

6. The method of claim 5, wherein the at least one sampling parameter is selected from the group consisting of a sampling rate, a laser power and a detector gain.

7. The method of claim 1, further comprising adjusting a focusing of the laser scanner in dependence on a focusing of the camera device.

8. The method of claim 1, wherein adjusting the laser scanner in dependence on the image comprises adjusting a confocality of the laser scanner in dependence on the image.

9. The method of claim 1, further comprising performing optical coherence tomography with the laser scanner, and adjusting focusing of the laser scanner to perform confocal laser scanning versus optical coherence tomography.

10. The method of claim 1, further comprising adjusting a confocal slice width of the laser scanner device to a depth of field range of the

Image.

1 1. Eye examination device comprising:

a camera device (103, 40) for taking an image of a part of an eye (10, 100) to be examined,

a laser scanner device (102; 41, 42, 14, 15, 1, 2) having a detection device (15), wherein the laser scanner device (102; 41, 42, 14, 15, 1, 2) is set up, at least a portion of the eye (10; 100) and to detect light emitted by the eye (10; 100) in response to the scanning, and

a control device (104) which is set up to set the laser scanner device (102; 41, 42, 14, 15, 1, 2) in dependence on the image.

12. The apparatus of claim 1 1, wherein the laser scanner means (102; 41, 42, 14, 15, 1, 2) and the camera means (103; 40) comprise a common ophthalmoscope lens (101; 9).

13. The apparatus of claim 1 1 or 12, wherein the laser scanner device (102; 41, 42, 14, 15, 1, 2) and the camera device (103; 40) have a common focusing device (24).

14. Device according to one of claims 1 1 -13, wherein the camera device (40) has a first camera (27) for the detection of light in the visible range and a second camera (26) for the detection of light in the infrared range.

15. Device according to one of claims 1 1 -14, wherein the camera device (40) has a perforated mirror (23) for combining and separating an illumination beam path and a detection beam path of the camera device (40).

16. The device according to claim 15, wherein a beam splitter (8) for combining a beam path of the laser scanner device with a beam path of the camera device is arranged between the perforated mirror (13) and a camera of the camera device.

A device according to any of claims 1-16, wherein the laser scanner means (41) comprises a pinhole (12), the control means (104) being arranged to set a size of the pinhole (12) in dependence on the image.

18. Device according to one of claims 1 1 -17, wherein the laser scanner device (102; 41, 42, 14, 15, 1, 2) is adapted to carry out confocal laser scanning.

19. Device according to one of claims 1 1 -18, wherein the laser scanner device (102; 41, 42, 14, 15, 1, 2) is set up to perform an optical coherence tomography.

20. Device according to one of claims 1 1 -19, wherein the camera device comprises a first module (40),

wherein the laser scanner device comprises a second module (41), wherein the first module and the second module can be coupled and decoupled.