Ophthalmological laser system with tomographic measuring system

Abstract

The present invention relates to an ophthalmological laser system (1), and to a method and a computer program product, for producing cuts in at least partially transparent tissue using a therapeutic laser module (2); a beam guiding device (6); a laser output (7) which has a holder for a transparent treatment interface (16) which can be docked to the at least partially transparent tissue; a tomographic measuring system (3); and a control device (21) which is designed to carry out the following steps: carrying out a measurement using the tomographic measuring system (3) while the treatment interface (16) is docked to the at least partially transparent tissue in order to generate a depth image of the at least partially transparent tissue; determining a spatial reference (32) in relation to the depth image, and outputting control information which provides a position and / or geometry of the at least one cut relative to the spatial reference (32) for control purposes.

Description

[0001] Ophthalmological laser system with tomographic measurement system

[0002] Description

[0003] The present disclosure relates to an ophthalmic laser system for generating incisions in at least partially transparent tissue, as well as a corresponding method and computer program product. The ophthalmic laser system comprises a therapeutic laser module, a beam guidance device for directing a therapeutic laser beam to a laser output and through a treatment interface attached thereto, a tomographic measurement system, and a control device configured to perform a measurement by the tomographic measurement system while the treatment interface is docked to the tissue in order to generate a depth image of the tissue.

[0004] State of the art

[0005] In ophthalmology, it is known to correct refractive errors of the eye, such as myopia, hyperopia and / or astigmatism, through refractive surgery, whereby the refractive power or refraction of the eye is changed.

[0006] Refractive surgical procedures are used to correct refractive errors. These procedures involve creating incisions in the corneal stroma, such as laser-assisted intrastromal keratomileusis (LASIK). In this procedure, a flap is created by cutting a flap from the cornea, typically using a femtosecond laser system. Such devices for cutting the cornea with a laser are also called laser keratomes or laser microkeratomes. The laser creates photodisruption at its focus, leading to the formation of tiny blisters within the stromal tissue. These blisters may or may not develop at the blisters. By placing blisters next to each other using a scanner system, incisions are made in the corneal tissue.During LASIK, the flap is lifted, and then stromal tissue is removed using an excimer laser. After the treatment, the flap is folded back into place.

[0007] Surgical refractive error correction has evolved into procedures that isolate and extract material from the cornea. The material to be isolated and extracted is commonly referred to as a lenticule, as it typically, but not necessarily, has the shape of a lens. The lenticule is then extracted through a small extraction incision in the cornea (e.g., SMILE: "Small Incision Lenticule Extraction"). Such a procedure is also referred to below as lenticule extraction. A laser keratome or laser microkeratome can be used for the necessary incisions, such as isolating the lenticule through incisions in the tissue or making an extraction incision to remove the lenticule. An example of an ophthalmic laser system capable of performing both flap incisions and lenticule delineation incisions is the Zeiss VISUMAX 600 / 800.This device features a laser keratome for cutting the corneal stroma on a first arm, through which a laser beam is guided and focused. For control and observation by the treating physician, a second arm is equipped with an operating microscope, which, however, only allows for en-face views of the eye.

[0008] In the aforementioned procedures, the shape of the cornea is specifically measured for planning surgical refractive correction, for example, contactlessly using a Scheimpflug camera or an optical coherence tomography system (also known as OCT, short for "optical coherence tomograph" or "optical coherence tomography"). Contact measurement using ultrasound is also known.

[0009] With established ophthalmic laser systems, patients are treated in a supine position. The measurements described above are typically taken beforehand outside the operating room using separate diagnostic devices, where the patient is measured while seated. This means that patients must be transferred and repositioned between ophthalmic laser treatments. Repositioning a patient who is still sedated or otherwise impaired due to a previous treatment is time-consuming and can lead to a negative patient experience.

[0010] Furthermore, repositioning the patient involves a process called cyclorotation, during which a spatial reference established prior to the procedure is lost between the patient's eye while lying down at the surgical laser and the patient's eye while seated at the diagnostic device. This reference must be re-established after repositioning, for example, through patient positioning and coordinate referencing. This re-establishment of the reference, as well as the transfer and repositioning process itself, increases the time and cost associated with post-operative diagnosis (i.e., diagnosis after corneal resection). This increased effort can lead the treating physician to forgo the necessary transfer, potentially overlooking indications for follow-up treatment and resulting in clinical disadvantages for the patient.

[0011] Furthermore, the laser-generated incisions can change during repositioning and transfer, for example, because gas bubbles in the eye may dissipate or be resorbed, making it impossible to identify the incisions within the eye. This is particularly important if an incision was incomplete, for example, due to eye movements during the incision procedure or the presence of substances, bubbles, or foreign bodies at the cornea-treatment interface.

[0012] Repositioning and transferring the cornea can therefore lead to misdiagnosis and a poorer treatment outcome, in addition to increased time and costs. During the actual procedure, i.e., while the incision is being made in the eye, the cornea is held in place by attaching a treatment interface to the laser keratome, which typically alters the cornea's shape. The term "attachment" refers to the process of placing / applanating and suctioning the treatment interface to the eye. Common treatment interfaces can have flat or spherical contact surfaces for contact with the eye. Consequently, the corneal shape parameters obtained outside of the actual procedure are only of limited value. This limits the accuracy of the laser treatment insofar as it relies on the previously measured shape.Problems that arise during the procedure must be resolved by the treating physician based on a top-view or "en face" view of the eye, possibly with the aid of an operating microscope. A depth view of the eye, i.e., a view of internal structures or a tomographic view, is generally not available.

[0013] From US 2014 276 674 A1 and US 11 076 990 B2, a system and a method for performing ophthalmic surgery on a non-docked eye using an ultrashort pulsed laser and an eye-tracking system are each disclosed. The surgical laser system has a laser device for delivering an ultrashort pulsed laser beam and optics configured to direct the laser beam onto a non-docked patient eye. An eye tracker for measuring five degrees of freedom of movement of the non-docked eye and an optical coherence tomography (OCT) device for depth measurement of the non-docked eye are provided to track eye movement. A controller for the system is configured to control the position of the laser beam on the non-docked eye based on the eye movements.The imaging devices in this system are specifically designed for tracking eye movements and controlling the laser beam based on the tracking data. This requires immense computational effort. Furthermore, a significant number and range of eye movements can occur, which can severely complicate treatments or even lead to treatment interruption or failure. US 10,500,093 B2 discloses an ophthalmic device for treating eye tissue, comprising a light source for generating laser pulses and a light projector for focused projection of the laser pulses into the eye tissue. The light projector is movable relative to the light source such that the length of the light transmission path from the light source to the light projector can be varied. The ophthalmic device also includes an interferometric measurement system, such as an OCT, for measuring eye structures.The interferometric measurement system enables flexible measurement of eye structures without requiring the ophthalmic device used to treat the eye tissue to be moved away from the patient and replaced with a measuring device. In one embodiment, the interferometric measurement system is coupled into the aforementioned light transmission path to allow measurement of the eye structures at and from the same position from which the laser pulses for treating the eye tissue are projected. This device only allows for a general OCT image of the eye.

[0014] US 10,779,989 B2 discloses a device for a laser-assisted ophthalmic surgical treatment system with a computer arrangement configured to provide so-called "pattern matching" for planning a surgical incision, i.e., prior to treatment, in order to establish a reference between previously acquired diagnostic data and image data from a first image acquisition unit. The first image acquisition unit, e.g., an OCT, is located at a treatment station together with a laser and can take images of the eye while docked. Such a system is designed and configured solely for planning incisions in the eye.

[0015] Furthermore, an ophthalmological laser system with a confocal laser scanning microscope is known from WO 2010 / 070020 A2 (Carl Zeiss Meditec AG). According to a disclosed method, a control unit determines irradiation control data for a laser surgical treatment. It then activates a fixation device and irradiates the cornea of ​​a patient's eye with the laser. The control unit also detects light backscattered from the examination area using the confocal laser scanning microscope, identifies an area of ​​the cornea in which opaque blisters are present, and irradiates at least the identified area again with the laser. The fixation device is then deactivated. Advantageously, the operator's consent can be obtained before the re-irradiation. Thus, this method can be used to identify specific errors in the laser irradiation of the eye.However, the operator's control options are limited in this process.

[0016] Summary of Revelation

[0017] The purpose of this disclosure is to reduce or eliminate disadvantages of the prior art. In particular, it aims to provide an ophthalmic laser system, method, and computer program product, each of which enables the improvement of clinical outcomes of ophthalmic laser-based procedures and / or a reduction in the time and cost of these procedures.

[0018] The problem underlying this disclosure is solved by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims.

[0019] More precisely, the task is solved by an ophthalmic laser system for creating incisions in at least partially transparent tissue (hereinafter referred to as "tissue"). The ophthalmic laser system comprises a therapeutic laser module with a therapeutic laser source configured to generate a therapeutic laser beam; a beam guidance device configured to direct the therapeutic laser beam to a laser output and focus it in a treatment area outside the laser output to create at least one incision in the at least partially transparent tissue; and the laser output, which features a holder for a transparent treatment interface that can be docked to the at least partially transparent tissue.Furthermore, the ophthalmic laser system has a tomographic measuring system with a detector configured to detect a measuring beam incident through the laser output and reflected by tissue structures; and a control unit configured to perform the following steps: performing a measurement by the tomographic measuring system while the treatment interface is docked to the at least partially transparent tissue in order to generate a depth image of the at least partially transparent tissue; determining a spatial reference with respect to the depth image (particularly within the depth image); and outputting control information that provides a position and / or geometry of the at least one section relative to the spatial reference for verification.

[0020] In other words, an ophthalmic laser system is provided with a laser keratome (the therapy laser module), a tomograph (the tomographic measurement system), and a control unit. The ophthalmic laser system is designed to create at least one incision in at least partially transparent tissue using the laser keratome, while the tissue is docked to a treatment interface at the laser output of the ophthalmic laser system. The laser keratome is therefore not designed to simply ablate tissue at a tissue surface or the like, but can create an incision within the tissue without it needing to be connected to a tissue surface.Furthermore, the ophthalmic laser system is designed to generate a depth image of the tissue while docked to the tomograph, particularly after at least one section has been created, and to establish a spatial reference. This allows the user to easily and quickly determine, for example, by optical comparison or measurement, whether the section was correctly positioned and / or whether its geometry is correct. For this purpose, the control unit provides the user with control information indicating the position or geometry of at least one section relative to the spatial reference. The spatial reference (and later, any additional spatial reference) will subsequently be referred to simply as the reference (or additional reference).According to the present disclosure, it is possible to avoid undocking the tissue and transferring it to separate diagnostic devices. Thus, the incision can be checked immediately after the procedure or after it has been created in the tissue, unlike with many commercially available devices. This allows a user to perform a particularly fast and accurate check of at least one incision immediately after it has been created, enabling quick and precise verification of whether the incision was made correctly. This is especially advantageous when the tissue in question is a patient's eye, as it avoids the disadvantages of repositioning the patient and reduces potential clinical disadvantages resulting from a delayed or omitted post-operative diagnosis.

[0021] The at least partially transparent tissue can be an eye, particularly corneal tissue from a patient, and / or a sample material. The sample material can be, for example, a tissue sample from which an implant is harvested, such as a donor eye, especially a donor cornea, or the like. Alternatively or additionally, the sample material can also be test tissue for testing the ophthalmic laser system. Alternatively or additionally, the sample material can also consist of artificial tissue.

[0022] A depth image, as defined in this disclosure, is one-, two-, or three-dimensional information about structures in tissue, at least along one depth direction. The depth direction is the direction in which the therapeutic laser beam exits the laser output. This preferably corresponds to a direction parallel to the optical axis of an eye or parallel to an axis passing through the center of the pupil of the patient's eye if the tissue is an eye or part of an eye and the eye is in a therapeutic position. The depth direction is also referred to as the z-direction. Directions perpendicular to the depth direction are referred to as the x-direction and y-direction, or as lateral directions. The tomographic measurement system is preferably configured to acquire A-scans, B-scans, and / or C-scans of the tissue and provide them as the depth image.An A-scan is a one-dimensional image of tissue along a depth direction or z-direction. A B-scan is an image of a sectioning plane extending along the depth direction of the tissue, essentially a cross-sectional view. A B-scan of a patient's eye can, in particular, extend along a radial plane with respect to an optical axis or an axis passing through the center of the patient's pupil. Specifically, a B-scan is obtained by combining multiple A-scans. A C-scan is a three-dimensional image of tissue and can, in particular, be obtained by combining a matrix of multiple A-scans or multiple B-scans.

[0023] It is conceivable that the control unit is designed to select a subset of depth profiles or data pairs from all recorded one-dimensional depth images or depth profiles. These subset profiles or data pairs are those recorded or generated at predetermined or selected xy-scan positions, particularly at a predetermined or selected line or grid. This can also be referred to as "remapping." This reduces the load on the storage or computing unit in which the data pairs are stored and / or processed. At the same time, a high resolution within the depth images can still be guaranteed. The remaining depth profiles or data pairs can, for example, be deleted or simply stored unprocessed.

[0024] The planning data (provided, for example, by the planning phase) can be used as a basis for selecting specific depth profiles or data pairs. This planning data can contain information about the coordinates / points / locations at which a blister was created in the tissue during a planned or performed treatment—that is, at which coordinates the therapeutic radiation to be applied or applied. The formation of such a blister depends on various parameters of the therapeutic radiation. Examples of such parameters are the pulse energy of a laser pulse to be introduced or introduced into the tissue, or the spatial distance between two adjacent pulses applied in the tissue (the so-called spot spacing). Furthermore, the planning data can also contain information about the type of laser pulse to be applied or applied.The term "type" can refer, for example, to specific spatial and temporal properties of the electromagnetic field of the therapeutic light / laser pulse to be applied or already applied.

[0025] For example, the planning data may contain information about the positions at which a pulse with a focus exhibiting a non-Gaussian (transverse) intensity profile is to be applied or has already been applied. While such a pulse with a non-Gaussian intensity profile can lead to photodisruption of the tissue in the cornea, this photodisruption may occur with the formation of an unstable blister. Such an unstable blister either "disappears" (diffusions) or is smaller than the resolution of a therapy camera. When sections are generated using such pulses, the sections are generally not visible in OCT scans.

[0026] Therefore, areas where laser pulses with a non-Gaussian focus profile are to be applied, or have been applied, cannot be included in the selection of specific depth profiles (i.e., they are deselected). Since no bubbles are generated or have been generated (or are visible) at these locations, an A-scan at these positions provides no information about the treated area. In other words, only A-scans of those locations where bubbles are generated or have been generated are planned and / or selected. Locations where a laser pulse with a non-Gaussian focus profile is to be applied, or has been applied, are preferentially excluded from selection. In this disclosure, "focus profile" refers to the transverse (i.e., measured perpendicular to the direction of laser propagation) intensity profile (location-dependent irradiance) at a focus of a laser beam.

[0027] A non-restrictive example of such a possible laser pulse with a non-Gaussian focus profile is a vortex beam (or electromagnetic radiation with a vortex-shaped electromagnetic field).

[0028] A previously mentioned remapping can be performed on this information contained in the planning data (optionally combined with other information), so that the remapping only includes A-scans of positions where a bubble is or has been generated, i.e., not those positions with planned or actual application of a laser pulse with a non-Gaussian focus profile. Meaningless data pairs (no bubbles -> no information via OCT) can thus be deselected and / or discarded.

[0029] A geometry of the at least one section within the meaning of this disclosure refers in particular to a geometric shape and / or size of the at least one section or, in other words, a course and / or completeness and / or section profile of the at least one section within the fabric. The geometry can, in particular, be a geometric shape of the section, which may be composed, for example, of one or more curved (three-dimensional) and / or planar (two-dimensional) section planes. The geometry of the section may, for example, include information about a curvature in an xz-plane and / or in a yz-plane, a circumferential shape (round, oval, diameter, etc.), or the like of the at least one section. If several sections are present in the fabric, the geometry may include information that represents the relative positions of the sections, such as...a thickness or thickness distribution in the depth direction of a lenticel that is formed between the sections.

[0030] A position of the at least one section within the meaning of the present disclosure refers in particular to a location of the at least one section in a lateral direction and / or the z-direction, especially with respect to a structure of the tissue. If the tissue is an eye, the structure of the tissue may in particular have an anterior and / or posterior corneal surface, a pupil center, an optical axis and / or the like.

[0031] Lateral deflection within the meaning of this disclosure means that the beam or beam path in question (i.e., the therapeutic laser beam and / or the measurement beam path) is angled and / or shifted such that its effective or measurement position in the treatment area is laterally displaced. The effective position of the therapeutic laser beam is defined by its focal point in the treatment area and essentially corresponds to the position at which the therapeutic laser beam can generate a spot. The measurement position of the measurement beam path corresponds to the position at which the tomographic measurement system generates the depth profile. The laser output is, in particular, an opening or a transparent section through which beams, e.g., the therapeutic laser beam during laser treatment, exit the ophthalmic laser system and enter the treatment area.The laser output is defined primarily by the mounting bracket, more precisely by a position in the Z-direction of the treatment interface when it is attached to the bracket. Even more precisely, an external surface of the treatment interface can determine the position of the laser output in the Z-direction. The mounting bracket is specifically designed to allow for the interchangeability of the treatment interface. The treatment area is the space outside the laser output in which the tissue is positioned during laser treatment. The ophthalmic laser system is specifically designed such that the laser output, in an operating position, has a fixed, predetermined relative position with respect to the therapy laser source.

[0032] Preferably, the ophthalmic laser system has a user interface designed for inputting data and / or commands. For example, the user interface may include a mouse, keyboard, joystick, buttons, touchscreen, voice control, gesture control, and / or similar devices.

[0033] Preferably, the ophthalmic laser system has a display device. The display device is specifically designed to output control information. The control unit can be configured to control the display device accordingly. The display device preferably has a display and / or an eyepiece, such as the eyepiece of a surgical microscope. The display can be provided, for example, on a monitor, as a head-up display, or the like. Furthermore, the display device can be a touchscreen and thus part of the user interface. This allows the user to receive information from the ophthalmic laser system via the display device and, if necessary, to input data into the ophthalmic laser system.The control information is information that provides information about a spatial relationship between measured structures of the tissue and the spatial reference, thus enabling the user to control the position and / or geometry of at least one section.

[0034] It is particularly advantageous if the control information includes a visual representation of the depth image and, optionally, the spatial reference, which is displayed to the user via the display device. This means the control unit is configured to output the depth image as part of the control information via the display device. Preferably, the spatial reference is displayed superimposed on the depth image. If the reference is located outside the depth image, for example, outside the treatment area, the display can optionally be extended to include the reference. This allows the user to check, using the display device, whether the at least one cut was executed correctly by visual inspection and / or by measuring the at least one section relative to the reference.

[0035] Alternatively, it is also conceivable that the control information is provided in such a way that it can be output to the user via text or audio output.

[0036] The user can preferably check the position and / or geometry of the section using the control information by verifying at least one section relative to the reference structure. For example, the control information can be displayed to the user in a display device as a graphic representation of the depth image and the spatial reference, or as a measurement result based on data from the depth image relative to the spatial reference (i.e., a result of a measurement of the section).

[0037] Preferably, the control device can be configured to prompt the user whether the section was performed correctly. Preferably, the user interface can include an input element through which the user can select a depth scan to be displayed on the display device. In particular, the user interface can provide the user with a selection option to choose what type of depth scan is captured and / or displayed. That is, the user can decide whether to view an A, B, and / or C scan and / or which area to view, e.g., which section plane is particularly relevant. More preferably, the control device is configured to control the display device, e.g., depending on the user's selection, to output the depth scan as A, B, or C scans on the display device.This gives the user a high degree of flexibility in selecting views and makes it particularly easy to identify errors in the section view.

[0038] The control unit is preferably configured to perform the measurement by the tomographic measuring system after the at least one section has been created. In other words, the control unit can preferably be configured to detect whether the cutting of the at least partially transparent tissue by the therapy laser module has been completed, and can further preferably be configured, after the cutting has been completed, to generate the depth image before the treatment interface is undocked from the at least partially transparent tissue. In other words, after the tissue cutting has been completed, the control unit can be configured to keep the laser output with the attached treatment interface in a docked state until the generation of the depth image is complete.This means that the tomographic measurement system can generate the depth image before the control unit performs a post-OP undocking (“post-OP”: after the operation, i.e., the at least one incision, is completed) of the treatment interface from the tissue.

[0039] In the context of this disclosure, "after at least one cut has been produced" refers in particular to a time during which the therapeutic laser was controlled to perform a cutting operation in order to generate spots of separated tissue along a defined cutting path, which together constitute the at least one cut. The at least one cut may comprise several cuts, which are performed immediately one after the other in a continuously planned cutting path or a continuously planned cutting operation. For example, the at least one cut may comprise lenticule delineation cuts and, optionally, an opening cut, which are performed sequentially by the therapeutic laser module in a (particularly automated) cutting operation.In particular, the cutting process is carried out, preferably automatically, without the therapy laser module being stopped in between to allow manual selection of further steps, undocking, or the like. Only afterwards is the depth image preferably generated.

[0040] Optionally, the depth image can also be generated before the cutting process is complete, for example, if only parts of at least one cut (parts of a complete cutting pattern) have been created. This allows the user to use the spatial reference for monitoring the treatment even during the procedure.

[0041] The depth measurement can be initiated automatically by the control unit. Alternatively, the control unit can be configured to prompt the user, e.g., via the display and / or the user interface, to determine whether and, if so, in what form (which plane, two-dimensional, three-dimensional) the depth measurement should be generated before undocking is initiated.

[0042] The at least one cut can comprise multiple cuts, which are performed consecutively in a continuously planned cutting path or process. Continuously planned means, in particular, that the execution of the at least one cut is not interrupted during normal operation (i.e., without an emergency stop or similar). For example, the at least one cut can comprise multiple cuts, which are performed sequentially by the therapy laser module in a single, especially automated, cutting process.

[0043] The at least one cut that can be performed by the ophthalmic laser system described above is preferably at least one lenticule delineation cut. Lenticule delineation cuts are cuts that define a lenticule. More precisely, lenticule delineation cuts include a so-called capcut, which defines an anterior surface of the lenticule; a lenticule cut, which defines a posterior surface of the lenticule; and optionally, a substantially ring-shaped sidecut, which connects the lenticule cut and the capcut and defines a circumferential border of the lenticule. Furthermore, the at least one cut may include an opening cut, also referred to as an "incision."The opening incision is a cut created during lenticule extraction to connect the lenticule margin incisions to the anterior corneal surface, thus opening the cornea and allowing the lenticule to be removed through the opening. If the incision is made incorrectly, lenticule extraction can be particularly difficult or even impossible, and the attempt can result in significant corneal damage. Therefore, it is especially advantageous to use the appropriate ophthalmic laser system to control the lenticule margin incisions. However, it is also conceivable that at least one of the incisions is, for example, a flap incision that defines a flap.

[0044] A spatial reference (hereinafter referred to as "reference") within the meaning of this disclosure is, in particular, a reference geometry, such as a point, a line, a plane, or any other structure, that is placed in spatial relation to the treatment area or the depth image, for example, for distance measurement or shape comparison. The spatial reference thus forms a reference geometry that is located, in particular, in the same virtual or real space that is captured by the tomographic measurement system. The ophthalmic laser system, or its control unit and user interface, can preferably be designed such that the user can select between different references or different control information. Some preferred examples of the reference or control information are described below.

[0045] The spatial reference can preferably be a virtual structure, which is inserted into the depth image by the control unit. In other words, the control unit can actively determine the spatial reference by selecting or creating the virtual structure and inserting it into the depth image. The term "virtual" structure is intended to indicate that the structure was created by the control unit and / or a user. Put another way, the virtual structure does not exist in the actual treatment room, but only in a virtual space created by the control unit, which contains the measurement data from the tomographic measurement system and the spatial reference. That is, the control unit can preferably be configured to overlay the virtual structure onto the (measured) depth image in order to provide the spatial reference.The depth image with the virtual structure inserted therein then preferably forms the control information, which is output to the user by the control device, in particular via the display device.

[0046] The virtual structure can preferably be a planned cutting contour of at least one cut. The planned cutting contour is preferably one that was planned prior to laser treatment of the tissue in order to create the cut. The ophthalmic laser system can include a planning unit that plans and provides the cutting contour. Alternatively, the planned cutting contour can be provided to the ophthalmic laser system by an external planning unit. The planned cutting contour can be stored in an electronic memory of the control unit or provided via a separate storage medium, e.g., a USB flash drive or wirelessly from a server or the like. The control unit can be configured to read the planned cutting contour and insert it into the depth image or superimpose it upon the image.In other words, the control unit can be configured to retrieve the planning data for generating at least one section and output it via the display device in such a way that the planned section contour overlays the depth measurement.

[0047] Such a virtual structure, serving as a spatial reference, allows the user to quickly and easily verify that the incisions made follow the planned contours, and in particular, whether they have the desired dimensions, position, and / or geometry. Furthermore, it enables the user to see whether the individual lenticule boundary cuts or cut components, such as the sidecut relative to the lenticule cut and / or the capcut, are correctly positioned relative to each other. Deviations, such as those caused by eye movements during the procedure, can thus be detected early and taken into account during further treatment, corrective treatment, and / or follow-up care.

[0048] It is also conceivable that the virtual reference has a virtual reference point for distance measurement, such as a fixed point or line with respect to the tomographic measuring system or the therapy laser module.

[0049] The spatial reference can be a measured structure from the depth image, in particular from at least partially transparent tissue, preferably the cornea of ​​an eye, or a structure of the treatment interface, such as its outer surface. In other words, the control unit can be configured to determine or use a structure measured by the tomographic measurement system as the spatial reference. The measured reference can be determined (automatically) by the control unit, which is designed to identify a predetermined or automatically selected structure in the depth image and designate it as the spatial reference. In this way, the determination of the spatial reference can be particularly fast. Alternatively, the control unit can be designed to determine the reference by acquiring user input, which the user uses to select the reference.The ophthalmic laser system can have a user interface through which the user can select a measured structure in the depth image as the reference.

[0050] It is particularly advantageous if the measured structure, which can be determined as the reference, is a structure that depends on certain section properties, such as a lateral or depth position or an extent of the at least one section. Selecting and determining the measured structure as the reference makes it possible to control the position and geometry of specific points or sections of the at least one section with particular precision. Preferably, the measured structure has one or more of the following structures of the at least partially transparent tissue:

[0051] - an outer tissue surface, in particular an anterior corneal surface and / or a posterior corneal surface,

[0052] - a vertex of the cornea (i.e., a point where an optical axis of the eye intersects the cornea),

[0053] - a pupil center,

[0054] - an edge of at least one cut in the tissue, and / or

[0055] - an area of ​​the treatment interface.

[0056] The treatment interface can be internal and / or external, with the latter being internal to the ophthalmic laser system (i.e., facing away from the treatment area or tissue) or external to the ophthalmic laser system (i.e., facing towards the treatment area or tissue). In particular, the outer tissue surface, especially the anterior corneal surface of the eye, is essentially in contact with the outer surface of the treatment interface when docked (possibly taking into account a fluid film or similar).

[0057] It is particularly preferred if the control device is configured to measure a distance between the spatial reference and the at least one section, in particular a specific segment or point of the at least one section. This makes it possible to determine with particular accuracy whether the lenticule is correctly positioned and / or whether it has the correct dimensions.

[0058] For example, the control unit can be configured to measure the depth of a cut, in particular a lenticule cut, more precisely a cap cut and / or lenticule cut, in the tissue. Specifically, the control unit is configured to measure the distance of the cut in the tissue to the spatial reference in the depth direction. The spatial reference can preferably correspond to an outer tissue surface (in particular a measured structure), preferably the anterior surface of the cornea or to an outer surface of the treatment interface. Optionally, the distance of the at least one cut to the posterior surface of the cornea can also be measured.

[0059] These measurements allow for the determination of residual tissue thickness, particularly corneal residual thickness (pachymetry). Corneal residual thickness is the thickness of the corneal tissue in the depth direction that remains after a tissue section is removed, for example, during lenticule extraction or tissue ablation. Insufficient corneal residual thickness could, among other things, lead to corneal instability, making it impossible to counteract intraocular pressure, or to damage the posterior tissue layer or flap during mechanical treatment steps such as lenticule extraction or flap inversion and retraction. This can result in the development of keratoconus, etc., or significantly impair the refractive outcome and the patient's vision after treatment.Therefore, it is advantageous to check the residual corneal thickness particularly quickly and easily after treatment using the therapy laser module and, if necessary, to correct the laser treatment or discontinue the treatment before any mechanical treatment steps are carried out.

[0060] Alternatively or additionally, the control unit can be configured to measure the distance between the cap cut and the lenticule cut, particularly in terms of depth. This allows, in particular, the thickness of the lenticule to be checked. The thickness of the lenticule can significantly influence the refractive treatment outcome, making it especially advantageous for the treating physician to be able to check it before the lenticule is removed. Therefore, it is beneficial to be able to quickly and easily check the thickness of the lenticule after treatment with the therapy laser module and, if necessary, adjust the laser treatment or discontinue it.

[0061] Another advantageous control option, for which the control device can be configured, is measuring from one lateral edge section of a lenticule boundary section to another (e.g., radially opposite) lateral edge section of the corresponding lenticule boundary section. This advantageously allows for the verification of a dimension, e.g., a diameter, and / or a shape of the lenticule's circumference.

[0062] If the planned section contour is defined as the reference, the control unit can advantageously be designed to measure a distance, particularly in the depth direction, between the planned section contour and the at least one section acquired by the tomographic measuring device. Specifically, the distance between certain areas or points of the at least one section and the corresponding points or areas of the planned section contour can be measured. This makes it possible to detect depth deviations of the at least one section from the planned section contour and to assess the severity of the deviation. Thus, a user is particularly well supported in deciding whether the at least one section was executed with sufficient accuracy to continue the treatment.

[0063] Alternatively or additionally, the control device can be configured to measure a lateral offset (i.e., in an x- or y-direction transverse to the depth direction) and / or an angular offset (i.e., a rotation about an axis parallel to the depth direction) between the planned section contour as the reference and a corresponding measured section contour. Particularly preferably, the control device can be configured to control the orientation of the lenticule's cylinder axis, for example, by controlling the tomographic measurement system to acquire a B-scan at each point in the meridian (i.e., at a specific angle or angular offset with respect to the axis parallel to the depth direction) where the steepest and / or shallowest slope (i.e., the smallest and / or largest radius of curvature or the largest and / or smallest thickness gain) of the lenticule section is found, assuming it has been executed correctly.In other words, the control unit can be designed to acquire a B-scan along the planned cylinder axis and / or an axis offset by 90° to the planned cylinder axis in the xy-plane. This allows for verification of the correct alignment and positioning of at least one section. Furthermore, the control unit can be designed to select multiple references. For example, it can be advantageous if the control unit is configured to provide the user with the planned section contour as a first reference and output it in the verification information. If the control unit detects, for example via user input, that there is an error in the position and / or geometry of at least one section, the control unit can be configured to determine a measured structure as a second reference, which is suitable for more precise verification of the faulty section.

[0064] Furthermore, the ophthalmic laser system can be used to check the quality of at least one incision in the depth image, including its homogeneity and / or the completeness of the spot pattern forming the incision. If the incision quality is too poor, this can lead to complications during incision opening and / or lenticule extraction. Therefore, the user can decide based on the depth image whether continuing the procedure is advisable or whether the incisions should not be opened to avoid potentially serious complications. In the latter case, planning a further procedure, such as a corrective surgery, may be considered.

[0065] Furthermore, the ophthalmological measurement system can be used to detect other tissue defects that could negatively impact treatment success. For example, the user can utilize the depth image to check whether local fractures have occurred in Bowman's membrane due to corneal incisions made with the therapy laser and / or during manual opening of the lenticule margin incisions, leading to microfolds in the corneal surface. This allows the physician or user to identify a deteriorating treatment outcome and either correct it or provide better follow-up advice to the patient. In addition, it is advantageous if the tomographic measurement system is also available for a control step after the removal of a tissue section, particularly after successful lenticule extraction.In particular, the control unit can be designed to generate an additional depth image after the cutting of at least one section with the therapy laser has been completed and undocking has occurred, either fully or partially. Partial undocking means that suction between the treatment interface and the tissue is released, but contact between the treatment interface and the tissue is maintained.

[0066] Subsequently, the control unit can be designed to determine an additional spatial reference relative to the additional depth image and preferably output additional control information that provides the position and / or geometry of a measured contour in the depth image relative to the spatial reference for verification. In particular, the additional depth image can be requested by the user, for example, via the user interface. This advantageously allows for a follow-up examination of the tissue after it has been detached and any further procedures have been performed. This helps the user decide whether further treatment steps are needed, whether the treatment should be discontinued, and / or how a patient can best be advised after treatment.

[0067] The additional depth image is processed or provided in the same manner as the depth image acquired before undocking. Furthermore, the additional spatial reference and the additional control information are selected, processed, or provided in the same manner as the spatial reference and control information determined or provided with respect to the depth image acquired before undocking. The additional spatial reference may be the same or different from the (first) spatial reference. Accordingly, each of the processing or provision steps described in this disclosure with respect to the depth image, reference, and control information provided before undocking can be applied equally to the additional depth image, reference, and control information.

[0068] Furthermore, the control unit can be designed to automatically or via user input detect that the device is undocked and / or that extraction has occurred. This allows for consideration of differences in corneal and lenticule shape between the undocked and docked states, as well as after lenticule extraction. For example, the control unit can use a different planned incision contour, a different planned incision depth, or similar parameters as the virtual reference in the undocked state and, if applicable, after lenticule extraction, compared to the docked state without lenticule extraction.

[0069] The control unit can be designed to reposition the laser output on or above the tissue, particularly on the patient's eye, to acquire the additional depth image. Alternatively, the user can reposition it manually. Advantageously, this allows for immediate tissue inspection after lenticule extraction or similar procedures, i.e., without transferring the patient for postoperative diagnosis. Among other things, the additional depth image enables the user to check whether and / or where lenticule remnants remain in the tissue or cornea that could impair the refractive outcome. If at least one incision is a flap incision, the additional depth image can be used to verify that the flap has been correctly repositioned.

[0070] The design of the ophthalmic laser system, which allows for a remeasurement of the eye after undocking, can be particularly relevant to the application of (re)imaging (e.g., under the laser arm) after the surgeon has performed a manual part of the treatment under the operating microscope, such as the extraction of the lenticule through the access incision, and wants to ensure, for example, that the lenticule has been completely removed from the eye, that no lenticule remnants remain in the treatment interface, or that false planes (manually created incisions in the eye by the tool that do not correspond to the planes cut by the laser system) etc. have been created.

[0071] At this point, i.e., immediately after the extraction of the lenticule, a patient may generally be unable to focus on a fixation light due to the procedure (edema, swelling, irrigation, etc.).

[0072] Since the eye is no longer docked, it can move freely at this point, which complicates imaging of the eye that is composed of multiple measurements. This applies, for example, to a measurement composed of several line scans, but also to a B-scan composed of several A-scans. Furthermore, artifacts can occur within A-scans due to a freely moving eye whose movement is not compensated for during a measurement. In other words, any OCT measurement of a freely moving eye without compensation and / or consideration of the movement carries an increased risk of obtaining an erroneous or even unusable result.

[0073] In order to nevertheless enable imaging composed of individual measurements taken at different points on the eye in a non-fixed (undocked) eye that cannot be directed by the patient towards a fixation light, the following solutions for compensating eye movement are conceivable.

[0074] The ophthalmic laser system or its control unit can be designed to detect eye movements using eye tracking based on the image from the therapy camera. Furthermore, the laser system or its control unit can be designed for corresponding real-time tracking of the measuring beam. In other words, the laser system or the control unit can receive eye direction or eye movement data from a device within the laser system (e.g., the aforementioned therapy camera) or from a device not belonging to the laser system.

[0075] Alternatively, the laser system or control unit can be configured to calculate eye direction or eye movement data from image or video data provided by a recording device, representing an image and / or video of the eye. In both cases, the control unit can be configured to control the beam guidance device based on the eye direction or eye movement data in such a way that the movement of the patient's eye is compensated. Compensation in this context means that a targeted point of the measurement beam path on the eye follows a movement of the eye by adjusting the beam guidance device, so that its relative position to the eye does not change.

[0076] Alternatively or additionally, the ophthalmic laser system or its control unit can be designed to detect eye movements using OCT. For example, OCT can be used to measure movement of the fovea, iris, or another, preferably easily visible or detectable, ocular structure. Furthermore, the laser system or control unit can be configured to perform real-time tracking of the measuring beam based on such OCT-measured / determined movement of the ocular structure. Eye movement is thus compensated for by adjusting the beam guidance device based on the position measurement of such a structure.

[0077] The variants shown, which are not limited and not exhaustive (eye tracking, OCT), for determining eye movement thus enable imaging of a non-fixed (undocked) eye that cannot be directed by the patient towards a fixation light, even if the eye should move.

[0078] It can be particularly advantageous if the control unit is designed to provide a live depth image after at least one incision has been made with the therapy laser module and the system has undocked. This live depth image is preferably a 3D image. This allows the user to utilize the tomographic measuring device for lenticule extraction. This simplifies orientation between the cap cut and the lenticule cut for the user and reduces the risk of errors when opening an incision in the tissue. Furthermore, it may eliminate the need for an operating microscope or operating microscope arm of the ophthalmic laser system, thus saving costs, installation space, and time associated with changing and positioning the operating microscope.To perform lenticule extraction using the tomographic measuring device, the second measurement area for the live depth scan must encompass the patient's eye (more precisely, the cornea of ​​the patient's eye). In other words, the working distance between the laser output of the laser arm and the patient's eye must be sufficiently large to allow the surgeon to perform the lenticule extraction, and the second measurement area must be adapted to this position of the patient's eye. It is crucial that the patient's eye is located within the second measurement area (the distance of the area to be treated within the eye, preferably the entire eye, lies between the boundaries of the second measurement area) and that sufficient maneuvering space remains between the patient's eye and the laser output for the surgeon's hand.Whether the laser output and thus the second measuring area is positioned towards the patient's eye (to the cornea of ​​the patient's eye) or the patient's eye is positioned towards the laser output is irrelevant.

[0079] As previously described, the outer boundary of the second measuring range in the z-direction has a distance (which can also be referred to as the maximum working distance) from the laser output of preferably > 5 cm. To enable lenticule extraction using the tomographic measuring device, this maximum working distance can preferably be > 15 cm, more preferably > 25 cm, and even more preferably up to 30 cm or > 30 cm.

[0080] Such a maximum working distance (up to which an OCT live depth image is possible) gives the surgeon enough space (between laser output and patient's eye) to perform the lenticule extraction and simultaneously allows a live depth image of the patient's eye to check or perform said lenticule extraction (without an operating microscope, as previously described).

[0081] The patient's eye is preferably positioned at a distance from the laser output that is smaller than the maximum working distance and larger than the minimum working distance. The minimum working distance defines the boundary of the second measurement range that is located closer to the laser output.

[0082] The control unit may be designed to allow the treatment interface to re-dock with the tissue before acquiring the additional depth image.

[0083] To perform TI (transient ischemic attack), particularly good results can be achieved with this measurement, as, for example, patient eye movements are largely prevented during the measurement. Furthermore, a particularly suitable or optimized acquisition area of ​​the tomographic measurement system can be set in the z-direction. Thus, exceptionally high image quality can be provided without the need for additional focus shifting mechanisms.

[0084] Alternatively, the control unit can be designed to acquire the additional depth image from the tomographic measurement system while undocked, i.e., without re-docking and at a distance from the tissue, or to bring the tissue into contact with the treatment interface before acquiring the additional depth image, without suctioning it. This allows for checks, e.g., after lenticel removal, to be performed without having to re-dock. This saves time when acquiring the additional depth image. Furthermore, it avoids the discomfort experienced by the patient due to re-docking the treatment interface with the tissue. Clinical disadvantages of re-docking, which can arise particularly from eyelid closure, mechanical pressure, and suction, are reduced. The patient can also blink, resulting in a better patient experience.Furthermore, it is possible to measure the structures within the tissue without deforming the tissue by attaching or docking the tissue surface to the treatment interface. Thus, monitoring can be performed without any deformation, and a correction step to compensate for deformation can potentially be omitted.

[0085] If the additional depth image is generated after undocking, particularly without re-docking, it is advantageous if the tomographic measurement system (more precisely, its measurement range in the depth direction) is set or adjustable such that the additional depth image can capture the extracted lenticule spread across the outer tissue surface, e.g., on the anterior corneal surface of an eye. In other words, the tomographic measurement system and / or the beam guidance device can be set or optionally adjustable such that the depth image can be generated by the tomographic measurement system both in a first measurement range immediately adjacent to or encompassing the laser output (especially a treatment interface held in the holder), and in a different, particularly wider, second measurement range.This allows the user to advantageously verify whether the lenticule has been completely extracted. This prevents lenticule remnants remaining in the tissue from leading to significantly poorer treatment outcomes and patient dissatisfaction during refractive surgery.

[0086] For more precise control of the extracted lenticel, it may be advantageous, even in this preferred embodiment of the present disclosure, to determine an additional spatial reference. The additional spatial reference may be a virtual or measured reference, as described above. The control device may be configured to determine a dimension and / or shape of the unfolded lenticel with reference to the additional spatial reference. This may optionally be stored for documentation purposes, such as in a documentation data set described in more detail below. Furthermore, it is conceivable that the control device may be configured to detect when a part of the lenticel is missing. A corresponding notification to the user may be part of the additional control information.Preferably, the control device can be configured to determine the dimensions and / or shape of a missing part of the lenticule, or to allow the user to determine this based on the control information. This enables the user to make early predictions about the quality of the treatment and the expected patient satisfaction, as well as to better advise the patient after the treatment. Furthermore, the user has the option, based on the control information, to perform a further intervention, such as a corrective procedure to rectify the previous treatment. An example of such a corrective procedure is the removal of lenticule remnants from the tissue. Particularly preferably, the tomographic measurement system can be configured to measure the structures in a measurement area that extends across the entire eye in the depth direction from the laser output (i.e., without any distance to the tissue when the laser output is docked to it).Preferably, the measuring range extends to a distance of at least 3 cm, preferably at least 5 cm, from the laser output in the z-direction (i.e., into the treatment area). Preferably, the measuring range can further extend over an area that covers the treatment interface, in particular the entire treatment interface in the z-direction. That is, preferably, the measuring range extends to a distance of at least -0.5 cm, preferably -1 cm, with respect to the laser output (i.e., away from the treatment area / towards the interior of the device). In other words, the measuring range with respect to the laser output in the z-direction preferably extends from -1 to 5 cm, more preferably from -0.5 to 3 cm.

[0087] It is particularly preferred if the measuring range includes the first and second measuring ranges.

[0088] The first measuring area can extend such that it encompasses at least one outer surface of the treatment interface, optionally the entire treatment interface, in the z-direction. In particular, an inner boundary of the first measuring area (facing away from the treatment room) in the z-direction can have a distance from the laser output of < 0 cm or = 0 cm, optionally < -0.5 cm, preferably < -1 cm. Furthermore, the first measuring area can extend such that it encompasses at least one anterior chamber of the patient's eye, preferably the entire patient's eye, when the treatment interface is docked. In particular, an outer boundary of the first measuring area (facing / lying within the treatment room) in the z-direction can have a distance from the laser output of > 1 cm, preferably > 3 cm.Thus, depth images of the tissue can be reliably generated in the docked state, and a measurement area for the docked state can be selected particularly advantageously. Furthermore, the second measurement area can extend such that it encompasses at least one outer surface of the treatment interface, preferably the entire treatment interface, in the z-direction. In particular, an inner boundary (facing away from the treatment area) of the second measurement area in the z-direction can have a distance from the laser output of < -0.5 cm, preferably < -1 cm. This is particularly advantageous for performing the calibration (described in more detail later) of the tomographic measurement system in the undocked state using at least one surface, preferably two surfaces, of the treatment interface.Furthermore, the second measuring area can extend such that an outer boundary (facing / located within the treatment room) of the second measuring area has a distance of > 3 cm, preferably > 5 cm, relative to the laser output in the z-direction. This corresponds in particular to an area in which at least the anterior chamber, preferably the entire eye, is located when the treatment interface is placed in front of the eye without docking. Thus, depth images of the tissue can be reliably generated in the undocked state without requiring excessively precise positioning of the laser output.

[0089] The control unit can preferably be configured to detect whether the treatment interface is docked and accordingly set the tomographic measurement system for acquisition in the first or second measurement range.

[0090] The measurement range is a region in which the tomographic measurement system, in particular the coherence wavelength, is configured to generate adequately sharp depth images, while outside the measurement range no usable images are possible. Specifically, a coherence wavelength is selected or set such that the tomographic measurement system is suitable for measuring the structures within the aforementioned measurement range. Measurement in such a range is particularly advantageous when the tomographic measurement system is used both in the docked state and after the tissue has been undocked. Preferably, the tomographic measurement system and / or the beam guidance device includes a focus shifting mechanism for shifting or changing the focus of the tomographic measurement system, in particular the OCT.The focus shifting mechanism is preferably configured to shift or change the measurement range in the depth direction, particularly between the first and second measurement ranges. This ensures that the tomographic measurement system or OCT can image tissue structures in several measurement ranges offset from each other in the depth direction with good quality. This can be advantageous, for example, if the focus shifting device allows different measurement ranges to be set for a depth image in the docked state and for an image in the undocked state.

[0091] The mechanism for shifting the focus of the tomographic measurement system preferably includes focusable optics in the beam path of the measuring light beam. The focusable optics can, for example, comprise a focusable collimator and / or a z-scan optic and / or a hinged lens, which are provided, in particular, upstream of the coupling point of the measuring light beam into the beam guide. If the tomographic measurement system is an OCT with a measuring arm and a reference arm (described in more detail below), the length of the reference arm can alternatively or additionally be adjustable. The reference arm can, in particular, be formed by an optical fiber whose length is variable. That is, the focus of the OCT can optionally be adjusted by making the reference arm adjustable, in particular by providing an adjustable reference fiber.

[0092] Alternatively, the tomographic measurement system can be configured for a measurement depth that does not require length adjustment of the reference arm or focusable optics, enabling the provision of a particularly simple and cost-effective system.

[0093] Alternatively, the imaging interface can provide an optical effect that fulfills the function of the focus shifting device between measuring area 1 (the first measuring area) and measuring area 2 (the second measuring area). Thus, the treatment interface can have an optical effect that, in conjunction with the beam guidance device, generates a measurement beam focus shift into measuring area 1. Similarly, the imaging interface can have an optical effect that generates a measurement beam focus shift into measuring area 2.

[0094] Purely exemplary and non-limiting possibilities for realizing such different optical effects of the two interfaces include differences in thickness or curvature between the two interfaces. In other words, the imaging properties of the optical system of the imaging interface differ from those of the optical system of the treatment interface; in particular, the focal length, i.e., the position of a focus, can differ for the two interfaces.

[0095] In a further embodiment, the imaging interface and / or the processing interface can have markings that allow differentiation from the treatment interface or the imaging interface in the therapy camera image or OCT.

[0096] Preferably, the control device, in particular a measurement control section described in more detail later, is designed to reconfigure acquisition parameters in order to adapt the tomographic measurement system to different foci or focus depths. Corresponding acquisition parameters may include a sweep rate, laser power, scan time, etc.

[0097] It is particularly advantageous if the control unit is designed to store the depth images and / or the control information and, after undocking, display them as a superimposed representation on the display unit. This superimposed representation can preferably include an image, in particular a top view of the tissue, which is captured by another image acquisition device (i.e., one other than the tomographic measurement system). This allows the user to be further supported during subsequent treatment steps, such as lenticule extraction, and thus improves the treatment outcome. In other words, the control unit can be designed to recognize identical structures in both a top view (also referred to as an "en face view") of the tissue and in the depth image.The additional image acquisition device may, for example, include an additional camera, an operating microscope, or the like. The control unit may then be configured to align and superimpose the top view, the control information, and / or the depth image based on the detected structures to create the superimposed display. It is particularly preferred if the ophthalmic laser system includes the operating microscope and the control unit is designed to superimpose or display alongside the control information, especially tissue structures identified in the depth image, an en-face view of the operating microscope, while the operating microscope is provided for viewing the tissue from above. This allows the user to be provided with particularly compact and easily accessible information during the subsequent procedure.

[0098] Furthermore, the control unit is preferably configured to save the measurement data of the tomographic measurement system, in particular the depth image and / or the control information, in a documentation data set, especially to save it automatically. This supports the user in documenting the treatment and saves time. Preferably, the documentation data set can also be used to improve a nomogram. This allows for an improved data basis for planning further treatments for the same or different patients.

[0099] Furthermore, the control unit can provide additional functions via the display device and / or the user interface. For example, the control unit can be configured to prompt the user to decide whether a treatment should be aborted or continued. It is also preferred that the control unit be designed to detect whether the at least one cut was executed correctly or incorrectly. For example, the control unit can provide a corresponding input element in the user interface through which the user can record whether the at least one cut was executed correctly or incorrectly. The control unit can preferably be designed to prompt the user to report errors in the cut pattern, such as irregularity and / or the completeness of a spot pattern forming the cut, and whether the user wishes to take further action.Alternatively, the control device can be designed to automatically identify errors in the cross-sectional image, to notify the user, and, if necessary, to provide the user with decision-making and planning aids for further measures.

[0100] If the user confirms that the cut was performed correctly or should be continued, the control unit may also be configured to undock the treatment interface from the tissue.

[0101] If it is detected that the incision was not performed correctly, the control unit may be preferably configured to perform one or more of the following steps: It may be configured to plan and, if necessary, perform a further ophthalmic procedure on the tissue using the therapy laser module, such as a corrective procedure to rectify an erroneous incision or the like. In particular, it may be configured to output the depth image, especially the control information, to a planning unit for planning ophthalmic procedures with the ophthalmic laser system.Alternatively or additionally, if a cut is detected as faulty, the control unit can be configured to calculate a recommendation for further action based on an existing database and display it to the user, thus providing decision support regarding whether to terminate the treatment or explore further treatment options. Alternatively or additionally, if a cut is detected as faulty, the control unit can be configured to terminate the treatment. In other words, the control unit can preferably be configured to output measurement data from the tomographic measurement system (directly or further processed) to a planning unit for planning a further intervention by the therapy laser module, such as a corrective procedure. The planning unit can be part of the ophthalmic laser system. The control unit is further preferably configured to perform the replanning.For planning further laser treatment or corrective surgery, the control unit can be configured to use diagnostic data determined before treatment and / or data of planned cutting contours, as well as depth data recorded after the cut has been made.

[0102] It is particularly advantageous if the control unit is configured to maintain the position of the laser output between the acquisition of at least one depth image and the corrective treatment, especially by keeping the treatment interface (at the patient's eye) in the docked position. This advantageously eliminates the need for intermediate docking and undocking, which can improve the outcome of the refractive correction, save time and costs, and reduce negative patient experiences.

[0103] Therapy laser module

[0104] The therapy laser module is designed to provide therapy laser radiation via the therapy laser source and to deliver this radiation as a therapy laser beam at the laser output. In particular, the therapy laser module is suitable and configured for performing lenticule extraction procedures (e.g., SMILE). The therapy laser beam is, in particular, a pulsed laser beam, preferably an ultrashort pulsed laser beam, and more preferably a femtosecond laser beam. The therapy laser module is designed such that the therapy laser beam, at its focus, is suitable for creating sections in at least partially transparent tissue (hereinafter referred to as "tissue"), in particular corneal tissue of a patient's eye or sample material.The energy density of the laser beam at its focus is adjusted such that spots of locally or point-like separated tissue (referred to as "spots") can be generated within the tissue, optionally with the formation of tiny bubbles or vesicles, also known as cavitation bubbles or gas bubbles. A series of these spots forming a pattern ("spot pattern" / "bubble pattern") creates an incision in the tissue. Furthermore, the therapeutic laser module is designed such that the energy density of the therapeutic laser beam outside its focus is adjusted so that it is hardly absorbed by the tissue, particularly corneal tissue. Preferably, the laser power is adjustable.

[0105] A higher laser power and / or a lower scan time is also preferred.

[0106] Therapeutic laser beam and / or a distance between scan points of the

[0107] The therapeutic laser beams can be adjusted relative to each other. This makes it particularly easy to integrate different imaging scan patterns into the therapy step.

[0108] The tomographic measurement system is a system that enables tomographic imaging of at least partially transparent tissue, particularly the patient's eye. This means it identifies tissue structures that can be displayed as depth images on the screen. Specifically, the tomographic measurement system is designed to capture structures within the tissue along the z-direction, or depth direction. These structures are primarily those that reflect or scatter light, or more precisely, interfaces between areas with different refractive indices. The tomographic measurement system can also be referred to simply as a tomograph.

[0109] Preferably, the tomographic measuring system includes a measuring light source, in particular a measuring laser source, which generates measuring light for illuminating the tissue, reflected by the structures within the tissue. The reflected measuring light enters the ophthalmic laser system through the laser output, is focused, and guided by the beam guide along the measuring beam path to the detector. Preferably, the measuring light source is connected to the measuring beam path such that the measuring light generated by the measuring light source is focused and guided by the beam guide to the laser output. That is, preferably, both the light emitted by the measuring light source and the light incident on the laser output are guided at least partially along the same path. Thus, targeted and particularly good illumination of the tissue area to be measured can be achieved.

[0110] The measuring light source is, in particular, a light source provided separately from the therapy laser source, especially a therapy laser source. The measuring light preferably has a coherence wavelength that differs from the coherence wavelength of the therapy laser radiation. This ensures that light from the therapy laser beam, reflected by the patient's eye, does not significantly interfere with the measurement by the tomographic measuring system. Alternatively, the measuring light can also have the same coherence wavelength as the therapy laser. Another alternative is to divert a beam from the therapy laser source from the therapy beam path and guide it, at least partially, along a different path than the therapy laser beam. This also ensures that no coherent superposition of the measuring light and the therapy light in the detector interferes with the measurement by the measuring device.

[0111] Preferably, the tomographic measuring system is an optical coherence tomography system (OCT for "optical coherence tomograph"). The OCT can have the measuring light source, in particular the measuring laser source, from which a measuring beam (in particular a measuring laser beam) and a reference beam (in particular a reference laser beam) are emitted. The reference beam and the measuring beam can be separated from each other, for example, by a beam splitter or fiber coupler, which is located downstream of the measuring laser source.

[0112] The measuring beam is guided to the tissue, in particular via a measuring arm, where it is reflected. The reflected light is then guided via the measuring arm to an interferometric detector. The interferometric detector has, for example, an interferometer arranged at the input side, which, among other things, superimposes the measuring beam and the reference beam to generate an interference beam, and one or more sensors, in particular photodiodes, for converting the light of the interference beam into electrical signals. Preferably, two sensors are provided for so-called "balance detection." The measuring arm thus essentially corresponds to the measuring beam path. The reference beam is guided to the detector, in particular via a reference arm, which is designed to measure interference between light from the measuring arm and the reference arm.

[0113] Preferably, according to the present disclosure, OCT images are acquired in the frequency domain ("frequency-domain OCT"). In frequency-domain OCT measurements, the detector detects interferences from individual spectral components of the measurement light source. The respective spectral component determines the measured depth. This enables simple and fast measurements, as a complete depth image can be acquired without the need for a movable reference mirror, the movement of which is time-consuming and can generate artifacts. Thus, high measurement stability and speed can be achieved. Furthermore, frequency-domain OCT offers particularly high sensitivity and requires a relatively low radiant power from the measurement light source, which increases the efficiency of the tomographic measurement system.Frequency-domain OCT typically distinguishes between the use of a tunable source ("swept-source OCT") and the use of a dispersive detector ("spectral-domain OCT").

[0114] According to the present disclosure, the tomographic measurement system is preferably a swept-source OCT. In swept-source OCT, the frequency of the measurement light source, often a measurement laser source, is sequentially tuned, i.e., the individual spectral components are provided by the measurement light source one after the other. That is, the measurement light source is preferably a tunable laser (swept source), for example, a broadband laser, a supercontinuum laser, and / or an ultrashort pulse laser. A VCSEL laser (vertical external-cavity surface-emitting laser) is particularly preferred. The tunable laser can be a narrowband light source at a given time, the center frequency of which can be selectively varied over time, or it can be composed of a plurality of narrowband light sources. Preferably, the sweep rate of the swept-source OCT is adjustable.This allows the OCT to be precisely adapted to the prevailing conditions, resulting in particularly high measurement accuracy and / or speed. A swept-source OCT can achieve exceptionally high sensitivity and a particularly low signal-to-noise ratio over a very large depth range.

[0115] Alternatively, a spectral-domain OCT can be used, in which (similar to time-domain OCT) a broadband light source is used, but the frequency components of the interference signal are not separated at the measuring light source, but before detection, for example by an optical grating.

[0116] Alternatively, OCT data can be acquired in a time domain ("time-domain OCT"). In this method, a movable reference mirror can be positioned in the reference arm. By moving the reference mirror, a path difference between the measuring beam and the reference beam can be adjusted, thereby setting the measured depth.

[0117] Alternatively, the tomographic measurement system could be a confocal system or a confocal microscope. This is a particularly cost-effective way to obtain a high-resolution depth image of the patient's eye, especially for measurements of the anterior segment. Alternatively, the tomographic measurement system could also be a two-photon microscope or an SHG imaging system, etc.

[0118] The ophthalmic laser system preferably has a base station which includes the (entire) therapy laser module, the (entire) beam guidance device, the laser output and the (entire) tomographic measurement system.

[0119] The base station preferably has a base housing from which a laser arm extends, on which the laser output is arranged. The laser arm can be pivotably, movable, or fixedly connected to the base housing. The therapy laser source is preferably arranged in the base station, more precisely in the base housing. The beam guidance device can extend through the laser arm and preferably through the base housing. The coupling point is also preferably arranged in the base housing. Furthermore, it is advantageous if the detector and, if applicable, the measuring laser source are arranged in the base station, more precisely in the base housing. The xy-scan optics and / or the z-scan optics can also be located in or on the base station, more precisely in the base housing and / or in the laser arm.

[0120] The laser output can be in a treatment position, which is the position in which the laser output is finally positioned for performing a treatment with the ophthalmic laser system. In other words, the laser output is in the treatment position when, for example, a treatment is to be performed and the patient is correctly positioned over or on the tissue so that the treatment interface can dock. The treatment position is, in particular, a fixed, predetermined position that the laser output assumes or can assume relative to the therapy laser source and, if applicable, to the measurement laser source and, if applicable, to the detector. More precisely, the treatment position is a fixed, predetermined position that the laser device arm assumes or can assume relative to the base housing in order to position the laser output.Preferably, the laser output, particularly with the laser arm, can be pivoted between (exactly) two positions: the treatment position and a passive position that differs from the treatment position and in which the therapy laser module and / or the tomographic measurement system cannot be used for laser therapy or tomographic tissue measurement. That is, in the passive position, the laser arm can be pivoted out of the way to create space at the tissue for the user and / or other devices.

[0121] Preferably, the tomographic laser system further comprises a microscope arm on which a surgical microscope is arranged. The microscope arm is preferably mounted to the base housing via a further pivoting device, in particular a further swivel joint. Preferably, the microscope arm can be pivoted between a treatment position and a passive position. In particular, the surgical microscope is located in the

[0122] The microscope arm is positioned in the same way as the laser output when the latter is in its treatment position. The microscope arm can be swivelled into its treatment position when the laser arm is in its passive position, and vice versa. This allows the treating physician to move the laser output away and the operating microscope into position after treating the tissue with the therapeutic laser beam, without repositioning the tissue or the patient.

[0123] Preferably, the base station also includes the display device. More preferably, the base station includes the entire control unit or at least certain functional sections thereof.

[0124] The beam guidance device is, in particular, an arrangement of optical elements designed to guide at least the therapeutic laser beam from the therapeutic laser source to the laser output, to focus it into the treatment area, and to control the position of the focus within the treatment area. For example, the beam guidance device has a focusing optic at or immediately before the laser output, which is provided for focusing the therapeutic laser beam into a treatment area outside the laser output.

[0125] Preferably, the beam guidance device has an xy-scan optic designed for laterally controlling the position of the therapeutic laser's focus. That is, the xy-scan optic is a mechanism for laterally controlling or shifting the focus of the therapeutic laser beam and / or the measurement beam path in the treatment area transversely to the depth direction or in an x ​​and / or y direction. It can have an x-scanner and a y-scanner. Control in the x and / or y directions, or in a lateral direction, in this sense means that the position of the focus is shifted in a direction that is transverse or perpendicular to the therapeutic laser beam at the laser output. The xy-scan optic can, for example, have a number of adjustable mirrors, particularly galvanometrically. It is especially advantageous if the measurement beam path's acquisition position is laterally controlled by the xy-scan optic.The acquisition position is a position in the treatment room at which the tomographic measurement system determines the depth of the scan. This means that, advantageously, only a single xy-scan optic is required for the lateral control of both the therapy laser beam and the measurement beam path. This reduces manufacturing and maintenance costs. Furthermore, the beam guidance device preferably includes a z-scan optic designed to control the position of the therapy laser's focus in a depth direction, i.e., in a z-direction or parallel to the therapy laser beam at the laser output. The beam guidance device may also include one or more additional components such as a collimator, mirrors, beam splitter, and the like.

[0126] Preferably, the beam guidance device incorporates a coupling point at which the measurement beam path can be coupled into or out of the beam guidance device, particularly concentrically to a therapy beam path of the therapy laser beam. In this case, the xy-scan optics are located at the coupling point or between the coupling point and the laser output. This ensures that the depth profile, especially the OCT scan, and the therapy treatment can be controlled together with exceptional precision, particularly using the same xy-scan optics.

[0127] Preferably, the coupling point is designed as a deflecting mirror that deflects the therapy laser beam when the therapy laser module is operated. More preferably, the deflecting mirror is a pinhole mirror through which the measuring beam is guided when the tomographic measuring system is operated. The pinhole mirror, i.e., its opening, is preferably located at a position where the therapy laser beam strikes the deflecting mirror (i.e., the pinhole mirror is concentric with the therapy laser beam). More preferably, the diameter of the pinhole mirror's opening is smaller than the diameter of the therapy laser beam at the point where it strikes the deflecting mirror. This is a particularly simple and elegant solution for coupling the measuring beam into the therapy laser beam without significantly impairing the quality of the therapy laser beam.Alternatively, the coupling point could incorporate a beam splitter cube that reflects the wavelength of the therapeutic laser beam and transmits the wavelength of the measurement beam, or vice versa. This can be particularly advantageous when the two wavelengths differ significantly. Another alternative is to achieve coupling by polarizing the therapeutic laser beam and the measurement beam differently, for example, by placing polarizers at or before the coupling point.

[0128] Preferably, the control unit is configured to perform a depth calibration of the tomographic measurement system. That is, the control unit is configured to control the tomographic measurement system in such a way that it detects a measurement position (i.e., a specific measured position) in the depth direction or z-direction and compares this measurement position with a known reference position in the depth direction or z-direction. Based on this comparison, the measurement data of the tomographic measurement system can be interpreted or adjusted. This ensures a particularly high level of measurement accuracy with each use of the tomographic measurement system. Depth calibration can be performed before each use of the tomographic measurement system, before each treatment with the ophthalmic laser system, or at specific times, such as at the beginning of a treatment day or before the initial commissioning of the ophthalmic laser system.

[0129] It is particularly advantageous if, to determine the measurement position, the depth position of a first surface of the transparent treatment interface (i.e., a position in the depth direction) is measured by the tomographic measurement system. Furthermore, it is advantageous if the control unit, especially its measurement control unit, uses a known position of the first surface of the transparent treatment interface in the depth direction as the reference position. In other words, during depth calibration, the treatment interface is attached to the ophthalmic laser system, and a surface of the treatment interface is used as a control or reference surface.

[0130] Preferably, the first surface of the transparent treatment interface is a flat surface, preferably perpendicular to the therapy laser beam when the treatment interface is attached to the holder. This allows for particularly easy calibration. In particular, the first surface is an inner surface of the transparent treatment interface, i.e., one facing the interior of the device or away from the treatment area in the z-direction. Alternatively, the first surface can also be a spherical surface, particularly an outer surface (i.e., facing away from the interior of the device or towards the treatment area), when the treatment interface is attached to the holder.

[0131] The reference position of the first surface can be measured by an additional measuring system, for example, an additional confocal measuring system, during ophthalmic laser treatment. Preferably, the reference position of the first surface is determined by reading out a position of the transparent treatment interface determined by the holding device and calculating the position of the first surface.

[0132] Alternatively or additionally, preferably, the measurement position can be a first measurement position, e.g., a position of the first surface (e.g., inner surface) of the treatment interface or an artificial target. Furthermore, the control unit can be configured to measure a second measurement position, e.g., a position of a second surface (e.g., outer surface) of the treatment interface or the artificial target, in the z-direction and to use the distance between the first and second measurement positions for calibration against a known reference dimension, in particular a known thickness of the treatment interface or artificial target. Alternatively, the control unit for calibrating the tomographic measurement system can be configured to perform a test section with the ophthalmic laser system, which has a first and a second section spaced apart in the z-direction.In this case, the first section of the test cut can be the first measurement position, the second section of the test cut the second measurement position, and the reference dimension is a distance between the two sections in the z-direction set by the ophthalmic laser system. The holder is preferably designed to accommodate one of at least two different treatment interfaces in an interchangeable manner. That is, the holder can be designed such that different treatment interfaces can be selectively attached and exchanged. Thus, the ophthalmic laser system can be adapted for different applications, achieving better results in each case. In particular, the treatment interface, or one of the at least two treatment interfaces, can be a therapy interface. Furthermore, the treatment interface, or another of the at least two treatment interfaces, can be an imaging interface.

[0133] The imaging interface can differ from the therapy interface in its design. For example, the therapy interface may have a suction feature, such as a vacuum connection. This allows the therapy interface to be used to hold or stabilize tissue during the procedure. The imaging interface, on the other hand, may lack a suction feature, such as a vacuum connection. Furthermore, the imaging interface may have characteristics that are better suited for tomographic imaging, such as a larger diameter or a different radius of curvature. Additionally, the imaging interface may be softer or more elastic than the therapy interface. This allows for particularly good depth images to be acquired by the tomographic measurement system, thus improving diagnosis by the physician or user.

[0134] The control unit is specifically designed to recognize which of the at least two different treatment interfaces is attached to the holder. The ophthalmic laser system may have a separate interface sensor for this purpose. Alternatively, it is also conceivable that a different design (e.g., dimensions or geometry) of the treatment interface can be detected by the tomographic measuring system or another measuring device of the ophthalmic laser system in order to identify the treatment interface. If the imaging interface is attached to the holder, the control unit may be configured to...

[0135] To prevent or avoid docking onto the tissue. The control unit is designed to control the ophthalmic laser system, in particular the therapy laser module, the tomographic measurement system, and the display device. The control unit of the ophthalmic laser system is designed to control the therapy laser module and the tomographic measurement system, as well as to control the procedures described herein, which are carried out using the ophthalmic laser system, in particular the therapy laser and the tomographic measurement system.

[0136] The control unit preferably has one or more of the functional sections described below, specifically a scan control section, a measurement control section, a therapy control section and a planning section, which are interconnected for data transmission or can optionally be connected.

[0137] Preferably, the control unit has a scan control section configured to control at least the xy-scan optics. That is, the preferred scan control section is configured to control the lateral deflection of a beam, such as the therapy laser beam and / or the measurement beam path, which is guided by the beam guidance device. Optionally, the scan control section can also be configured to control the z-scan optics and / or other components of the beam guidance device. Preferably, the scan control section can be configured to issue control commands to or communicate with the measurement control section, for example, to trigger the acquisition of a depth profile at the predetermined xy-scan position.

[0138] By selecting predetermined xy scan positions, the scan pattern (or a capture pattern or imaging scan pattern) can be obtained. The scan pattern can comprise a selection from all captured A-scans.

[0139] Such an acquisition pattern (also: acquisition profile, i.e., an imaging scan pattern or part of an imaging scan pattern) can, purely as an example, be based on planning data (treatment planning data), i.e., be created depending on the planning data. For example, the planning data could include information representing where a blister will be created or has been created in the tissue. These locations can thus each be considered a trigger event, with all locations (with a blister to be created or already created) being represented in their entirety by the acquisition pattern. The control unit is configured accordingly to interpret such an acquisition pattern and generate an A-scan at the planned locations.

[0140] Analogous to the procedure described in the previously described example of remapping with laser pulses with a non-Gaussian focus profile, the trigger events in this example can also be generated or provided depending on the type of laser pulse. This means that at locations where a laser pulse with a non-Gaussian focus profile is applied or has been applied, there is no trigger event per se. The subset of possible measurement positions obtained by excluding these positions can optionally be further restricted by additional criteria (for example, by requiring a B-scan to be obtained along a specific meridian). Such conditions for selecting a subset of measurement positions can be combined arbitrarily.

[0141] In remapping, depth profiles are selected from an entire measurement beam trajectory that were recorded at the corresponding positions where a bubble is generated.

[0142] The selection of measurements already taken is therefore based on the planning data.

[0143] Alternatively, as described above, trigger events are created based on the planning data.

[0144] In this case, the measuring beam can be guided post-OP (using the beam guidance device) so that only certain positions within a treatment trajectory are visited where visible bubbles were generated.

[0145] In the first case, post-processing of a large number of measurements takes place, while in the second case, it is more accurate to speak of pre-processing, since the location of the measurements is determined before the actual measurements are taken.

[0146] Both post-processing and pre-processing using the planning data and the information it contains about the spatial and / or temporal parameters of the laser pulses to be applied or already applied with a non-Gaussian focus profile are particularly advantageous as long as the cut lenticule is still in the patient's eye. Once lenticule extraction has begun, a prior or subsequent selection of the measurement positions (individual A-scans) is no longer useful for the following reasons.

[0147] Once the remaining tissue bridges of the incisions are severed, the separated incision is visible in an OCT image, regardless of whether the incision was made using laser pulses with a Gaussian focus profile (forming temporarily present bubbles) or using laser pulses with a non-Gaussian focus profile (without remaining bubbles).

[0148] Particularly at a time after lenticule extraction, when the lenticule may be preferentially placed on the ocular surface for monitoring purposes, considering the information on where laser pulses with a non-Gaussian focus profile were applied is obsolete.

[0149] Preferably, the control unit further comprises a measurement control section configured to control the tomographic measurement system. This means the measurement control section is configured to control the measurement light source and / or read and process data from the detector (e.g., to store it and / or generate a depth image from the data and / or provide the data or depth image). For example, the measurement control section can include a CPU or GPU, RAM, and / or a storage unit. Preferably, the measurement control section is further configured to control the measurement laser source and / or communicate with the scan control section, in particular to issue control commands to the scan control section and / or receive xy-position data from the scan control section. The measurement control section can thus optionally control, via the scan control section, which part of the tissue is measured, e.g., to measure the defect areas.

[0150] Preferably, the control unit has a therapy control section configured to control the therapy laser module. In particular, the therapy control section is configured to control the therapy laser source. Preferably, the therapy control section is further configured to communicate with the scan control section, in particular to issue control commands to the scan control section. That is, the therapy control section can, if necessary, control via the scan control section which part of the tissue is to be treated with the therapy laser beam.

[0151] The control unit may preferably include a planning section configured to process input from the user interface and to plan a treatment and / or measurement. The planning section may be configured to output planning and / or control data to the other functional sections of the control unit (measurement control section, therapy control section, planning section, scan control section). It may also be configured to receive data from the measurement control section and, if necessary, to consider it in planning corrective treatment or the like. Furthermore, it may be configured to control the display device in order to output the depth measurement to a user. Finally, the planning section may be configured to process and execute commands from the user interface or to consider them in the planning process.

[0152] The control unit is preferably integrated into the base station, in particular the entire control unit. Alternatively, the control unit can be provided separately from the base station, either wholly or partially (e.g., one or more of the aforementioned functional sections), and be connected to it for data transmission, or optionally connectable, e.g., via a wireless or wired connection or, for example, for transmitting treatment planning data, even via a portable storage device such as a memory stick or the like. Optionally, the control unit can also be connected to a third-party system, such as a hospital system, for data transmission, or optionally connectable.

[0153] The control device can be a single computing unit with a CPU, a GPU, RAM, a storage unit, and / or the like, which is or are programmed or configured to perform steps according to this disclosure. Alternatively, the control device can have several separate computing units configured to communicate with each other, i.e., which are connected or optionally connectable for data transmission, e.g., via a wireless or wired connection. Each computing unit can have one or more of the functional sections. The computing units can each have a CPU, GPU, RAM, a storage unit, and / or the like, which is or are programmed or configured to perform steps according to this disclosure. The computing units can have the functional sections of the control device individually or in groups.

[0154] Alternatively or additionally, the problem underlying the present disclosure is solved by a method for monitoring an ophthalmic laser treatment for generating at least one incision in at least partially transparent tissue by an ophthalmic laser system comprising a therapy laser module, a laser output with a treatment interface attached thereto, a control device, and a tomographic measuring system, in particular by an ophthalmic laser system as described above. The method comprises the following steps:

[0155] - Performing a measurement using the tomographic measurement system after at least one section has been created and while the treatment interface is docked to the at least partially transparent tissue in order to generate a depth image of the at least partially transparent tissue;

[0156] - Determining a spatial reference in relation to the depth of field (especially in the depth of field); and

[0157] - Output of control information that provides a position and / or geometry of at least one section relative to the spatial reference for verification.

[0158] Since the user is supported in their treatment decisions, including the planning of further treatment, by the control information, this procedure can also be described as a planning procedure.

[0159] The method may further include all steps described in the present disclosure concerning the control of the ophthalmic laser system and its components. The components of the ophthalmic laser system include, among others, the control unit, the therapy laser module, the tomographic measurement system, and the beam guidance device.

[0160] The problem underlying the present disclosure is further solved by a computer program product for monitoring an ophthalmic laser treatment by an ophthalmic laser system, in particular one described above. The computer program product has a program code which, when executed by the control unit of the ophthalmic laser system, performs the aforementioned method.

[0161] Character description

[0162] The present disclosure is described below with reference to a preferred embodiment and the figures. These figures are exemplary and are not intended to limit the present disclosure.

[0163] Fig. 1 shows a schematic example of the setup of an ophthalmic laser system.

[0164] Fig. 2 shows a schematic depth representation of a treatment interface.

[0165] Fig. 3 illustrates a first and a second measuring range.

[0166] Figures 4, 5, and 6 show depth images provided in a control procedure according to the disclosure. Figure 7 schematically shows a control view in which a lenticule has been spread out on the eye after extraction.

[0167] Fig. 1 shows an ophthalmic laser system 1 according to a preferred embodiment. The ophthalmic laser system 1 has a base station with a therapy laser module 2 and a tomographic measuring system 3.

[0168] The therapy laser module 2 has a therapy laser source 4, which generates a therapy laser beam 5. The therapy laser beam 5 is guided by a beam guidance device 6 to a laser output 7 of the ophthalmic laser system 1. At the laser output 7, the therapy laser beam 5 exits the ophthalmic laser system 1 to create incisions in at least partially transparent tissue. In this example, the at least partially transparent tissue is tissue from a patient's eye 8, specifically its cornea, but it could also be another type of tissue.

[0169] The beam guidance device 6 has various optical components configured to guide and shape at least the therapy laser beam 5. The beam guidance device 6 has x- and y-scanners, which form an xy-scan optic 9 and are controllable to deflect the therapy laser beam 5 and shift a focus of the therapy laser beam 5 in an x-direction and / or a y-direction, i.e., perpendicular to a beam direction of the therapy laser beam 5. Furthermore, the beam guidance device 6 has a z-scan optic 10, which is controllable to adjust a focus of the therapy laser beam 5 in the z-direction, i.e., in a depth direction of the patient's eye 8. The beam guidance device 6 may also include other components, e.g., for compensating for aberrations, for beam shaping, and the like, a collimator, etc.

[0170] According to the preferred embodiment, the tomographic measuring system 3 is an OCT, in particular a so-called swept-source OCT. The OCT has a measuring light source 11, in particular a measuring laser source, which emits a measuring beam 12 and a reference beam 13, in particular a reference laser beam. The reference beam 13 is guided from the measuring light source 11 to a detector 14. The measuring beam 12 is guided from the measuring light source 11 to a coupling point, where it is coupled into the beam guidance device 6, or can be selectively coupled into it. The coupling point can be, for example, at the xy-scan optics 9 or at the z-scan optics 10. Preferably, the measuring beam 12 is coupled into the beam guidance device 6 at a position upstream of or directly adjacent to the xy-scan optics 9, i.e., upstream of or adjacent to the first of the x- and y-scanners, so that the same beam guidance device 6 can be used to guide both the therapy laser beam 5 and the measuring beam 12., the measuring beam 12 runs parallel, preferably concentrically (shown parallel in Fig. 1 only for better clarity), to a path of the therapy laser beam 5 between the coupling point and the laser output 7.

[0171] The measuring beam 12 is guided by the beam guide 6 to the laser output 7 and exits the ophthalmic laser system 1 there to detect structures in the patient's eye 8. If the measuring beam 12 is reflected back into the laser output 7 by structures in the patient's eye 8, it is guided back to the detector 14 by the beam guide 6. In the detector 14, the reflected measuring beam 12 interferes with the reference beam 13, thus enabling the detection of structures in the patient's eye 8. Any scattered light reflected from the therapy laser beam 5 does not interfere with the detection of the reflected measuring beam 12, or only minimally, because the measuring beam 12 and the therapy laser beam 5, or the reference beam 13, have different coherence lengths.

[0172] The ophthalmic laser system can be operated in different modes. In the first mode, the therapeutic laser beam 5 is active and the measuring beam 12 is inactive. In the second mode, the therapeutic laser beam 5 is inactive and the measuring beam 12 is active. In the third mode, both the measuring beam 12 and the therapeutic laser beam 5 are preferably active. When both the therapeutic laser beam 5 and the measuring beam 12 are active, they are directed simultaneously to the laser output 7 to exit and treat or measure the patient's eye 8. In this case, the measuring beam 12 is coupled into the therapeutic laser beam 5 at the coupling point. For example, the measuring beam 12 is shaped into a narrow beam by a pinhole mirror 15 and coupled centrally into the beam path of the therapeutic laser beam 5. In particular, the pinhole mirror 15 is designed as a deflecting mirror that deflects the therapeutic laser beam 5.In particular, the therapy laser beam 5 is wider at the coupling point than the therapy laser beam 5, so that the therapy laser beam 5 does not significantly impair the power of the therapy laser beam 5. That is, the therapy laser beam 5 has sufficient power for its function of creating cuts in the eye tissue even when the measuring beam 12 is active at the same time.

[0173] The laser output 7 has a holder for a treatment interface 16, which is transparent to the therapy laser beam 5 and the measuring beam 12. The treatment interface 16 can be attached to the holder interchangeably.

[0174] The base station of the ophthalmic laser system 1 has a base housing and a laser arm 17, which extends from the base housing and is preferably pivotable or movable via a first joint mechanism. The laser arm 17 is, in particular, adjustable between a treatment position (Fig. 1), in which the laser output 7 is directed towards the treatment of the patient's eye 8, and a passive position, in which the laser arm 17 is pivoted away from the patient's eye 8.

[0175] The beam guidance device 6 is at least partially integrated into the laser arm 17. The coupling point is located, in particular, in the base housing. The therapy laser source 4 and the measurement laser source 11 are integrated into the base housing. The laser output 7 is located at an end section of the laser arm.

[0176] 17. The coupling point, at which the measuring beam 12 is coupled into the beam guidance device 6, is located in the base housing, i.e. between the therapy laser source 4 and the laser device arm 17.

[0177] Furthermore, a camera is mounted on the laser device arm 17, in particular on its end section.

[0178] 18 is arranged, which is configured to capture an en-face view of the patient's eye 8. It can provide the en-face view before, during, or immediately after a measurement with the tomographic measurement system 3.

[0179] A microscope arm 19 can also be pivotably attached to the base housing via a second joint mechanism. This arm has an end section to which an operating microscope 20 is attached. The microscope arm 19 is movable, in particular, between a treatment position and a passive position (Fig. 1). In the treatment position, one entrance of the operating microscope 20 faces the patient's eye 8, and in the passive position, the microscope arm 19 is pivoted away from the patient's eye 8. The microscope arm 19 can be pivoted into its treatment position when the laser arm 17 is in its passive position, and vice versa.

[0180] In a measuring beam path along which the measuring beam 12 runs, in particular in the beam guiding device 6, a focus shifting device F can be provided to adjust a measuring range of the tomographic measuring system 3.

[0181] The ophthalmic laser system 1 according to the preferred embodiment further comprises a control unit 21, which is configured to control functional units of the ophthalmic laser system 1. The control unit 21 is connected via data transmission at least to the measuring light source 11 and the therapy laser source 4, the xy-scan optics 9, the z-scan optics 10, and the detector 14. The control unit 21 can be provided as a central processing unit, e.g., a CPU. Alternatively, the control unit 21 can be provided as a distributed system and can be provided in several networked computing units. The entire control unit 21 is preferably provided in or on the base station, i.e., physically connected to or attached to it.

[0182] Preferably, the control unit 21 has a measurement control section 22, which is configured to control the tomographic measurement system 3, in particular to control the measurement light source 11 and to process data from the tomographic measurement system 3. Preferably, the control unit 21 also has a therapy control section 23, which is configured to control the therapy laser module 2, in particular to control the therapy laser source 4 and optionally the z-scan optics 10, as well as optionally an AOM and various filters and shutters, which are not shown here. Furthermore, the control unit 21 can have a scan control section 21, which is provided for controlling the xy-scan optics 9 and optionally the z-scan optics 10. The therapy control section 23 and the measurement control section 22 are connected to the scan control section 21 for data transmission in order to send control commands for scanning therapy scan patterns 30 and 10, respectively.To output imaging scan pattern 31 to the scan control section 24 and / or to receive position data from it.

[0183] According to the preferred embodiment, the control unit 21 further comprises a planning section 25, which is configured to plan a treatment or corrective treatment of the patient's eye 8 with the therapy laser module and to output corresponding control data to the measurement control section 22, the therapy control section 23, and the scan control section 21. Furthermore, the planning section 25 can be configured to receive, process, and output the data from the measurement control section 22 as one-dimensional images (A-scans) or in the form of a two-dimensional (B-scan) or three-dimensional (C-scan) depth representation of the patient's eye 8 on a display device 26 of the ophthalmic laser system 1.

[0184] Furthermore, the control unit 21 of the ophthalmic laser system 1, in particular the therapy control section 23 and / or the measurement control section 22, is configured to detect the position of the treatment interface 16. For example, a position sensor 27 is provided for detecting the position of the treatment interface 16, which is designed to determine an exact position of the treatment interface 16, at least in the z-direction. The position sensor 27 can preferably be a confocal measurement system, which is designed to detect a reference position in the z-direction of at least one reference surface of the treatment interface 16. The control unit 21, in particular the measurement control section 22, is further configured to measure the position in the z-direction of the at least one reference surface of the treatment interface 16 and to calibrate it with the at least one reference position determined by the position sensor 28.The ophthalmic laser system 1 further comprises at least one user interface 28, which is configured for the input of data and / or commands by a user. For example, the user interface 28 may include a keyboard, a joystick, a touch display, buttons, foot pedals, or the like. The planning unit 25 is then configured to receive and process commands from the user interface 28, e.g., to take them into account when planning or processing the data of the measurement control section 22.

[0185] Fig. 2 schematically shows a B-scan of the treatment interface 16, which was acquired by the tomographic measuring system 3. The treatment interface 16 has an inner surface 30 facing the interior of the device and an outer surface 31 facing the exterior of the device or the patient's eye 8. The outer surface 31 is preferably a contact surface designed for contact, in particular docking, with the patient's eye 8. When calibrating the tomographic measuring system 3, the inner surface 30 can, for example, serve as a reference surface. Alternatively or additionally, the outer surface 31 can serve as a reference surface. Alternatively or additionally, a distance between the inner surface and the outer surface can serve as a calibration measure. In Fig. 2, the positions of the inner surface 30 and outer surface 31, which are detected by the measuring laser beam 12, are represented by dots.

[0186] Fig. 3 shows a first measuring area M1, which extends in the z-direction from an outer surface 30 of the laser output or the treatment interface 16, and a second measuring area M2, which encompasses the treatment interface 16 and extends further into the treatment space in the z-direction than the first measuring area M1. The first measuring area M1 and the second measuring area M2 can be adjusted by the focus shifting device F.

[0187] Fig. 4 shows a first preferred embodiment for outputting control information to the user. A B-scan acquired by the tomographic measuring device 3 is shown. The B-scan is displayed to a user, e.g., a treating physician, on the display device 26. The depth representation of the patient's eye 8 has a resolution that allows the user to identify a spot carpet 31 in the cornea of ​​the patient's eye 8. Thus, immediately following laser treatment and before the laser arm of the ophthalmic laser system 1 is removed from the treatment position, the user can check the spot carpet 31 and make decisions about further treatment based on this. Furthermore, in the depth representation, an apex of the cornea is selected as a preferred example for the spatial reference 32 (indicated by a white dot). This spatial reference 32 can be used, for example, to determine the extent of the damage.The depth of the lenticule in the cornea can be determined.

[0188] Fig. 5 shows a second preferred embodiment for outputting control information to the user. A B-scan of the patient's eye 8, acquired by the tomographic measuring device, is shown. The B-scan is displayed to the user in the display device 26. The control unit 21, in particular the planning section 25, determines planning data for the planned incision and superimposes planned section lines onto the B-scan, which are another preferred example of a spatial reference 32. In this way, the user can check the correct position of the incision or the spot pattern 31 in the depth direction.

[0189] Fig. 6 shows another preferred embodiment for outputting control information to the user, which can be additionally acquired after undocking and opening of the incision in the tissue. Shown is a B-scan of the patient's eye 8, acquired by the tomographic measuring device 3 after a lenticule was removed from the cornea of ​​the patient's eye 8. This allows the user to check whether the lenticule has been completely removed.

[0190] Fig. 7 schematically shows a further step for monitoring the treatment, which can be performed after undocking and opening the incision in the tissue. It depicts an en face view of the patient's eye 8, onto which an extracted lenticel 33, shown only schematically, has been spread out to verify the completeness of the extracted lenticel 33. A spatial reference 32 in the form of a planned incision contour (circumference of the lenticel) is superimposed on the spread-out lenticel, making it easy to identify any missing lenticel fragment.

[0191] Reference character list

[0192] 1 ophthalmological microscope arm

[0193] Laser system 20 surgical microscope

[0194] 2 Therapy laser module 21 Control unit

[0195] 3 Tomographic measuring system 22 Measuring control section

[0196] 4 Therapy laser source 23 Therapy control section

[0197] 5 therapy laser beam 24 scan control section

[0198] 6 Beam guidance device 25 Planning section

[0199] 7 Laser output 26 Display device

[0200] 8 At least partially 27 Position sensor transparent fabric (eye) 28 User interface

[0201] 9 xy-scan optics 29 inner surface

[0202] 10 z-scan optics 30 outer surface

[0203] 11 Measuring light source 31 Spot carpet

[0204] 12 measuring beam 32 spatial reference

[0205] 13 Reference beam (reference arm) 33 Extracted lenticule

[0206] 14 Detector F Focus shift mechanism

[0207] 15-hole mirror

[0208] M1 first measuring range

[0209] 16 Treatment interface

[0210] 17 Laser device arm M2 second measuring range

[0211] 18 Camera

Claims

Claims 1. Ophthalmic laser system (1 ) for producing incisions in at least partially transparent tissue with - a therapy laser module (2) with a therapy laser source (4) which is designed to generate a therapy laser beam (5); - a beam guidance device (6) which is configured to guide the therapy laser beam (5) to a laser output (7) and to focus it in a treatment area outside the laser output (7) in order to produce at least one cut in the at least partially transparent tissue; - the laser output (7), which has a holder for a transparent treatment interface (16) that can be docked to the at least partially transparent tissue; and - a tomographic measuring system (3) with a detector (14) which is configured to detect a measuring beam (12) incident through the laser output (7) and reflected by structures of the at least partially transparent tissue; - a control device (21) which is configured to perform the following steps: o Performing a measurement by the tomographic measurement system (3) while the treatment interface (16) is docked to the at least partially transparent tissue in order to generate a depth image of the at least partially transparent tissue; o Determining a spatial reference (32) with respect to the depth image, and o Outputting control information which provides a position and / or geometry of the at least one section relative to the spatial reference (32) for verification.

2. Ophthalmological laser system (1) according to claim 1, wherein the control device (21) is designed to control the measurement by the to perform tomographic measurement after at least one section has been produced.

3. Ophthalmological laser system (1) according to claim 1, wherein the spatial reference (32) has a virtual structure which is inserted into the depth recording by the control device (21), in particular a planned cutting contour of the at least one cut.

4. Ophthalmic laser system (1) according to claim 1, wherein the spatial reference (32) comprises a measured structure of the depth recording, in particular of the at least partially transparent tissue or the transparent treatment interface.

5. Ophthalmological laser system (1) according to claim 1, wherein the control device (21) is configured to measure a distance between the spatial reference (32) and the at least one cut, in particular a specific section or point of the at least one cut.

6. Ophthalmic laser system (1) according to claim 1, wherein the control device (21) is configured to measure a distance of the at least one cut in the at least partially transparent tissue to the spatial reference (32) in a depth direction, wherein the spatial reference (32) preferably corresponds to an outer surface of the at least partially transparent tissue.

7. Ophthalmic laser system (1) according to claim 1, wherein the control device (21) is designed to take an additional depth image, in particular to provide a live depth image, after cutting the at least one cut with the therapy laser module (2) has been completed and undocking has taken place.

8. Ophthalmological laser system (1) according to claim 1, wherein the tomographic measuring system (3) and the beam guidance device (6) are set or optionally adjustable such that they can record the depth measurement both in a first measuring area (M1) immediately adjacent to the laser output (7) and in a second measuring area (M2) spaced apart therefrom.

9. Ophthalmological laser system (1 ) according to claim 8, further comprising a focus shifting mechanism (F) for shifting a focus of the tomographic measuring system (3) between the first measuring area (M1 ) and the second measuring area (M2).

10. Ophthalmological laser system (1) according to claim 1, wherein the control device (21) is designed to store the depth image and / or the control information and, after undocking, to output it as a superimposed representation in a display device (26), in particular by the control device being designed to superimpose the depth image and / or the control information onto an image which is captured by a further image capture device.

11. Ophthalmological laser system (1) according to claim 1, wherein the control unit (21) is designed to query whether the at least one cut was performed correctly or incorrectly and whether a new or corrective treatment should be carried out by the therapy laser module (2); and, if it is detected that the new or corrective treatment should be carried out, to provide the depth image or data based thereon to a planning unit (25) of the control unit (21).

12. Ophthalmic laser system (1) according to claim 1, wherein the control device (21) is configured to perform a depth calibration of the tomographic measuring system (3) by determining a measuring position of a first structure, in particular a position of a first surface of the transparent treatment interface (16), which is connected to the the tomographic measurement system (3) is recorded and compared with a known depth position, in particular a position of the first surface of the transparent treatment interface (16).

13. Ophthalmic laser system (1) according to claim 1, wherein the holder is configured to interchangeably hold one of at least two different treatment interfaces (16), one of which is an imaging interface, and wherein the control device (21) is configured to detect whether the imaging interface is attached to the holder.

14. Method for monitoring and / or planning an ophthalmic laser treatment for generating at least one cut in at least partially transparent tissue by an ophthalmic laser system comprising a therapy laser module, a laser output with a treatment interface attached thereto, a control device and a tomographic measuring system, in particular by an ophthalmic laser system according to one of the preceding claims, comprising the following steps: - Performing a measurement using the tomographic measurement system while the treatment interface is docked to the at least partially transparent tissue in order to generate a depth image of the at least partially transparent tissue; - Determining a spatial reference in relation to the depth measurement; and - Output of control information that provides a position and / or geometry of at least one section relative to the spatial reference for verification.

15. Computer program product comprising a program code which, when executed by the control device of an ophthalmic laser system, in particular according to one of claims 1 to 13, executes the method according to claim 14. 65

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