Method for providing control data for an ophthalmic surgical laser and treatment device with at least one corresponding ophthalmic surgical laser

Abstract

Method for providing control data for an ophthalmic surgical laser (18) of a treatment device (10), wherein the method comprises the following steps performed by means of a control device (20): - Determining a first and at least a second cross-sectional surface (14, 16) in a cornea (26) of a human or animal eye, - Establishing an incision path which, starting from an outer surface of the cornea (26), divides and extends on the one hand to the first cutting surface (14) and on the other hand to at least the second cutting surface (16), - wherein the incision path has a first path (17a) extending from the outside into a volume of the cornea (26), and which splits at a node (17d) into a second path (17b) and at least a third path (17c), wherein the second path (17b) extends from the node (17d) to the first cut surface (14) and the at least third path (17c) extends from the node (17d) to the at least second cut surface (16), - Providing control data for controlling the ophthalmic surgical laser (18), which includes at least the defined incision path, characterized in that - the second and third routes (17c) enclose an angle between 70 and 120 degrees at the node.

Description

[0001] The invention relates to a method for providing control data for an ophthalmic surgical laser of a treatment device. The ophthalmic surgical laser can be used, for example, to perform refractive error correction in a human or animal eye. The ophthalmic surgical laser can, for example, be controlled to detach a corneal volume from the cornea with predefined interfaces. This corneal volume is hereinafter also referred to as a lenticule.

[0002] The invention also relates to a method for controlling a treatment device with at least one corresponding ophthalmic surgical laser, a control device for carrying out the respective method, a treatment device, a computer program and a computer-readable medium.

[0003] Treatment devices and methods for controlling lasers, which are used, for example, to correct refractive errors of the cornea, are known in the prior art. For example, a pulsed laser and a beam focusing device can be configured such that laser beam points within a focus located in corneal tissue cause an optical breakthrough, in particular photodisruption, at a predetermined cut surface. Two such cut surfaces can define or delimit a lenticule to be removed. Thus, by irradiating the tissue with the laser, the lenticule can be detached from the cornea.

[0004] To extract the detached lenticule from the corneal tissue, an incision is made starting from the outer surface of the cornea. This type of incision is also called a slit. The incision is made to reach the specific cutting surface, or cutting plane.

[0005] The incision is made to access the specific cut surface, for example, the upper and lower boundaries that define the lenticule. It may be necessary to manually refine or recut the cut surface before removing the lenticule to ensure the laser treatment was successful. This allows, for example, the separation of any tissue remnants or bridges left behind by the laser from the surrounding corneal tissue. A medical instrument, particularly a cutting device, can be inserted through the incision and then used to cut along the cut surface. The corneal tissue to be removed can then be extracted through the incision.

[0006] Various types of incisions are known from the prior art. For example, it is possible to make only one incision in the cornea for lenticule extraction. This incision can, for instance, run directly from the outer surface to an intersection of the interfaces bordering the lenticule, or to a cross-sectional surface of the interfaces leading to that intersection point. However, the intersection point may not represent optimal access to the interfaces.

[0007] Alternatively, multiple incisions, for example one incision for each of the interfaces, can be made in the cornea.

[0008] For example, DE 10 2020 112 277 A1 discloses a method for controlling an ophthalmic surgical laser in which two different incisions are made in the cornea to extract a lenticule.

[0009] From DE 10 2007 019 813 A1, a device for creating cutting surfaces for a lenticule in the cornea of ​​an eye for the correction of refractive errors is known. In this process, two spaced-apart opening cuts are made in the cornea and guided to the lenticule.

[0010] From US patent 2015 / 0 057 644 A1, a method for removing a lenticule from a cornea is known, in which respective channels are guided to an anterior and posterior interface of the lenticule for removal of the lenticule.

[0011] Furthermore, publication EP 3 988 063 A1 describes an ophthalmic device for surgical treatment of a cornea, and publication US 2004 / 0243112 A1 describes a device and a method for ophthalmic surgical procedures using a femtosecond fiber laser.

[0012] To gain access to different surfaces or planes within the cornea, current techniques require multiple incisions from the outer surface of the cornea to the respective incision site. This has the disadvantage of placing additional stress on the corneal tissue. As a result, the healing process for a patient after refractive correction can be prolonged.

[0013] The object of the present invention is to provide a means of providing access to different cutting surfaces within a cornea during refractive error correction, while avoiding additional stress on the tissue.

[0014] This problem is solved by the independent patent claims. Advantageous embodiments with expedient further developments of the invention are specified in the respective dependent patent claims. Advantageous embodiments of an independent patent claim are to be regarded as advantageous embodiments for the other independent patent claims, and vice versa.

[0015] The invention is based on the realization that access to multiple planes, i.e. the cross-sectional surfaces within the cornea, can be achieved with a branching incision pattern.

[0016] Accordingly, the invention proposes a method for providing control data for an ophthalmic surgical or ophthalmic laser treatment device. The method comprises the following steps, performed by means of a control unit: First, a first and at least a second cutting surface or cutting planes are determined in a cornea of ​​a human or animal eye. That is, at least two, i.e., two or more cutting surfaces, can be provided.

[0017] The cutting surfaces can be located in different planes along the optical axis of the eye, starting from an outer surface of the cornea. Alternatively, the cutting surfaces can be arranged, for example, in the same plane along the optical axis, i.e., particularly adjacent to one another. The cutting surfaces can, for example, form interfaces in a known manner that delimit a lenticule or define the lenticule geometry. That is, the cutting surfaces can have one or more points of intersection and / or a cutting plane. The first cutting surface can, for example, form a so-called posterior interface, and the second cutting surface can form a so-called anterior interface.

[0018] Next, an incision path, specifically exactly one incision path, is defined. The incision path specifies the geometry for the incision, that is, the cut leading to the cut surfaces. Starting from an outer surface of the cornea, the incision path divides and extends on one side to the first cut surface and on the other side to at least the second cut surface. That is, the incision path begins on the outer surface, specifically at an incision point on the outer surface of the cornea, and ends at different points on the respective cut surfaces. The incision path branches out.

[0019] The incision path has a first path extending from the outer surface into a volume of the cornea. That is, the first path projects into the volume of the cornea. The first path divides at a node into a second path and at least a third path. This means that at least two, or two or more, additional paths are provided. Preferably, exactly one additional path is available for each cut surface. The second path extends from the node to the first cut surface. The at least third path extends from the node to the at least second cut surface. That is, each of the additional paths can extend from the node to exactly one of the cut surfaces.

[0020] The incision path thus comprises at least three sections or segments, namely at least path paths one, two, and three, which are connected at the node and link the outer surface and the cut surfaces. The incision path can be geometrically described as a so-called tree graph. The path paths can be edges of the tree graph. The nodes can be nodes, especially internal nodes, of the tree graph.

[0021] The paths can geometrically describe a line segment or a bounded straight line or curve with a predefined curve shape or trajectory. At one end, the paths are bounded by the node, and at the other end by the respective point on the outside or the respective interface.

[0022] Preferably, the incision does not end at the intersection of the two cut surfaces, but at an interface between the respective cut surfaces that differs from the intersection point. That is, at least two cut surfaces are defined within a volume of the cornea, which are to be reached by a single, continuous incision.

[0023] Finally, the process provides control data for the ophthalmic surgical laser, which includes at least the defined incision path. Specifically, the control data can include the geometry and position of the incision path, i.e., a three-dimensional description of the incision path. Of course, the control data can also additionally or alternatively include the defined cutting surfaces, i.e., the geometry and position of the cutting surfaces, within the corneal volume.

[0024] The control data can also include a data set for positioning and / or focusing individual laser pulses within the cornea. This data set can, for example, contain coordinate values ​​in three-dimensional space representing treatment points or areas for the laser eye surgery. The treatment points collectively define the cutting path. This cutting path can encompass the incision line and the cut surfaces. To remove tissue, the laser beam is focused onto the treatment points within the cornea. This means that the laser beam's energy required for tissue removal is delivered to a specific coordinate point in a desired plane within the cornea. In this way, the cut surfaces and / or the incision line can be traced or irradiated. The coordinate values ​​can be described using coordinates in a suitable coordinate system (Cartesian, polar, cylindrical).

[0025] The control data may additionally or alternatively include a respective data set for setting at least one beam device for beam guidance and / or beam shaping and / or beam deflection and / or beam focusing of a laser beam of the respective laser.

[0026] Furthermore, the second and third routes at the junction enclose an angle between 70 and 120 degrees.

[0027] This change in direction offers the advantage of creating a perceptible edge or point of impact for medical personnel performing corneal correction. This results in particularly easy guidance along the incision line to the respective interface, thus avoiding additional tissue damage.

[0028] By creating a branched incision pattern in the cornea, the advantage is that multiple cut surfaces, particularly corneal interfaces, can be reached with just one incision starting from the outer surface. This places less stress on the corneal tissue than with two separate incisions. The wound healing process is also simplified compared to conventional methods that involve only one incision.

[0029] The cut surfaces can encompass a predefined position and / or geometric description within the cornea. This can be calculated, for example, from refractive error data. The calculation methods used for this purpose are well-known. For example, to remove a lenticule, a refractive power or diopter value to be corrected can be specified, which can then be used to determine the lenticule to be removed. In particular, the "collapse" or closure of the cornea after removal of the lenticule results in the desired correction.

[0030] The position and / or geometric description of the incision path can be determined based on the geometry and position of the cut surfaces. The determination of the geometry and position of the incision path is described in more detail later. Here, the incision path is considered specifically as a two-dimensional graph, i.e., its course in a cross-section axially to, or along, the optical axis of the eye.

[0031] The invention also includes embodiments that offer additional advantages.

[0032] According to one embodiment, the second and / or at least the third path exhibit a change of direction relative to a direction and / or radius of curvature of the first path in their respective directions.

[0033] In other words, at least one of the two or three paths changes direction compared to the first path. The other path, the one that does not change direction, preferably maintains the direction or radius of curvature of the first path. The incision path can therefore have a y-curve or a serpentine curve.

[0034] In this context, a change of direction refers specifically to the fact that one or more direction vectors describing the paths or segments thereof, relative to a reference plane such as the outer surface or one of the respective interfaces, run in different directions or are oriented differently. This change of direction can thus cause a change in the slope of the respective path. The point at which the change of direction occurs can be, for example, an inflection point or an extremum. The change of direction can also result in a kink in the incision path.

[0035] It can be particularly advantageous if the first and third or the second and third route paths, or respective sections from which the respective route path may be composed, enclose an angle between 70 and 120 degrees, preferably approximately 90 degrees.

[0036] Changing the direction of the incision offers the advantage of creating a perceptible edge or point of impact for medical personnel performing the corneal correction. This allows for particularly easy guidance of the incision line to the respective interface, thus avoiding additional tissue damage.

[0037] The direction of travel and the radius of curvature refer specifically to the section of the first path that ends at the node. This can be relevant, for example, if the paths themselves each comprise several sections.

[0038] According to another embodiment, the routes are essentially straight lines. That is, the routes can be straight segments that converge at exactly one intersection. This offers the advantage of making guidance particularly easy for medical personnel.

[0039] According to a further embodiment, at least the first path has at least one change of direction. Thus, the first path can comprise two or more different sections or segments. That is, the path can be composed of at least two sections. The sections change direction relative to each other, as described above. In contrast to the paths, the sections are preferably branchless or without branches. The sections can therefore have a continuous path.

[0040] According to a further embodiment, the second path or the at least third path exhibits at least one change of direction in their respective directions. Thus, exactly one of the paths can comprise two or three different sections or segments, as already described for the first path. The sections exhibit a change of direction relative to each other, as previously described.

[0041] Preferably, in this context, only one of the at least two paths exhibits a change of direction both internally and relative to the first path. The other of the at least two paths preferably does not exhibit a change of direction (direction-free) either internally or relative to the first path. Thus, the path without the change of direction after the node can continue in the same direction or with the same radius of curvature as the first path. The other path, however, changes its course. Therefore, the overall incision path can, for example, take the form of a branch or a step.

[0042] According to a further embodiment, both the second path and the at least third path exhibit at least one change of direction in their respective directions. Thus, paths two and at least three can comprise two or more different sections or segments, as already described for the first path. The sections exhibit a change of direction relative to each other, as previously described.

[0043] Preferably, in this context, at least the two incision paths exhibit a change of direction both internally and relative to the first path. This type of incision path can be described as a fork shape.

[0044] According to a further embodiment, the second and at least third pathways run parallel to each other, at least in sections. This results in a particularly easy-to-follow pathway for medical personnel to follow in order to reach the respective interface.

[0045] According to a further embodiment, the second and / or at least third pathways run at least sectionally, preferably substantially parallel to one of several corneal tissue layers running parallel to the outer surface. Preferably, the second and / or at least third pathways run between adjacent corneal tissue layers running parallel to the outer surface. This reduces the number and area of ​​tissue layers damaged by the incision.

[0046] These tissue layers are formed from collagen fibrils in a known manner. A multitude of these tissue layers, stacked along the optical axis and running parallel to the outer surface, form the cornea. The course or structure of the tissue layers can be estimated based on the known geometry and structure of the cornea, or measured, for example, using established imaging techniques or standard methods. From this, it is possible, for instance, to model how the layers are arranged within the volume of the cornea.

[0047] Preferably, the first incision path, starting from the outer surface, runs at least partially, and in particular entirely, essentially perpendicular to the outer surface. That is, the first incision path connected to the outer surface can run at approximately a 90° angle to the outer surface. This ensures that the smallest possible area of ​​the tissue structures is damaged by the incision.

[0048] From the junction point, one can then attempt to follow the course of the fibrils, as described previously, and in particular to cut between two adjacent tissue layers. This approach minimizes the area of ​​fibrils damaged, thereby reducing irritation for the patient and accelerating the healing process.

[0049] According to a further embodiment, the laser is suitable for emitting laser pulses in a wavelength range between 300 nm and 1400 nm, preferably between 900 nm and 1200 nm, with a pulse duration of between 1 fs and 1 ns, preferably between 10 fs and 10 ps, ​​and a repetition frequency greater than 10 kilohertz (kHz), preferably between 100 kHz and 100 megahertz (MHz). The use of such lasers in the method according to the invention also has the advantage that the irradiation of the cornea does not have to take place in a wavelength range below 300 nm. This range is referred to in laser technology as "deep ultraviolet." This advantageously avoids unintentional damage to the cornea caused by these very short-wavelength and high-energy beams.Photodisruptive and / or ablative lasers of the type used here typically deliver pulsed laser radiation with a pulse duration between 1 fs and 1 ns into the corneal tissue. Such lasers are known as nanosecond lasers, picosecond lasers, or femtosecond lasers.

[0050] This allows the power density of the respective laser pulse, necessary for optical breakthrough, to be spatially tightly limited, thus enabling high cutting accuracy in the generation of interfaces. The wavelength range between 700 nm and 780 nm can also be selected.

[0051] Another aspect of the invention relates to a method for controlling a treatment device. This method comprises the steps of at least one embodiment of the method as previously described. Furthermore, the method for controlling the treatment device includes the step of transmitting the provided control data to at least one ophthalmic or surgical laser of the treatment device.

[0052] The respective procedure may include at least one additional step that is executed precisely when a use case or application situation occurs that is not explicitly described here. This step may, for example, include the output of an error message and / or a prompt for user feedback. Additionally or alternatively, it may be provided that a default setting and / or a predetermined initial state is set.

[0053] Another aspect of the invention relates to a control device configured to perform the steps of at least one embodiment of one or both of the previously described methods. For this purpose, the control device may include a computing unit for electronic data processing, such as a processor. The computing unit may comprise at least one microcontroller and / or at least one microprocessor. The computing unit may be implemented as an integrated circuit and / or a microchip. Furthermore, the control device may include an (electronic) data storage device or a storage unit. Program code, which encodes the steps of the respective embodiment of the respective method, may be stored on the data storage device. The program code may include the control data for the respective laser.The program code can be executed by the processing unit, which then causes the control unit to execute the respective configuration. The control unit can be designed as a control chip or control device. The control unit can, for example, be part of a computer or computer network.

[0054] A further aspect of the invention relates to a treatment device comprising at least one ophthalmic or surgical laser and a control unit configured to perform the steps of at least one embodiment of one or both of the previously described methods. The respective laser can be configured to at least partially separate one or more predefined cut surfaces in the cornea, in particular a corneal volume with predefined interfaces of a human or animal eye, by means of optical breakthrough, in particular by means of photodisruption, and / or to ablate corneal layers and / or to cause a laser-induced change in the refractive index of the cornea and / or the lens of the eye.

[0055] Another aspect of the invention relates to a computer program. The computer program comprises instructions that, for example, constitute program code. The program code can include at least one control data set with the respective control data for the respective laser. When the program code is executed by a computer or a computer network, it is caused to execute the method described above, or at least one embodiment thereof.

[0056] Another aspect of the invention relates to a computer-readable medium (storage medium) on which the aforementioned computer program or its instructions are stored. To execute the computer program, a computer or a computer network can access the computer-readable medium and read its contents. The storage medium is, for example, designed as a data storage device, in particular at least partially as a volatile or non-volatile data storage device. A non-volatile data storage device can be flash memory and / or an SSD (solid-state drive) and / or a hard drive. A volatile data storage device can be RAM (random access memory). The instructions can be, for example, in the form of source code of a programming language and / or as assembly language and / or as binary code.

[0057] Further features and advantages of one of the described aspects of the invention may arise from further developments of another aspect of the invention. The features of the embodiments of the invention can therefore exist in any combination with one another, unless they have been explicitly described as mutually exclusive.

[0058] Additional features and advantages of the invention are described below with reference to the figure(s) in the form of advantageous embodiments. The features or combinations of features of the embodiments described below can be combined with each other and / or with the features of the embodiments. That is, the features of the embodiments can complement and / or replace the features of the embodiments, and vice versa. Therefore, embodiments that are not explicitly shown or explained in the figures, but which can be derived and generated from separate combinations of features in the embodiments and / or embodiments, are also to be considered as encompassed and disclosed by the invention.Thus, embodiments that do not exhibit all the features of an originally formulated claim, or that go beyond or deviate from the combinations of features set out in the references of the claims, are also to be considered disclosed.

[0059] This shows: Fig. 1 a schematic representation of a treatment device according to an exemplary embodiment; Fig. 2 a schematic representation of an incision path according to a first exemplary embodiment; Fig. 3 a schematic representation of an incision path according to a second exemplary embodiment; Fig. 4 a schematic representation of an incision path according to a third exemplary embodiment; and Fig. 5 A schematic process flow diagram for providing control data for the treatment device according to an exemplary embodiment.

[0060] In the figures, identical or functionally equivalent elements are provided with the same reference symbols.

[0061] The Fig. Figure 1 shows a schematic representation of a treatment device 10 with an ophthalmic surgical laser 18 for the separation of a lenticule 12 defined by control data from a cornea 26, for example by means of photodisruption and / or ablation. This can, for example, correct a refractive error.

[0062] The figures show the cornea 26 in a cross-section, i.e., a side view, in a plane that runs axially to the optical axis of the eye. The cornea 26 is bounded along an optical axis by an anterior corneal surface 30 and a posterior corneal surface 32. For the separation of the lenticule 12, a posterior or first interface 14 and an anterior or second interface 16 of the lenticule 12 are specified in the control data. A cavitation bubble path can be generated on these interfaces to separate the lenticule 12 from the cornea 26. These interfaces 14 and 16 form cutting surfaces along which a cut can be made to separate the lenticule 12. It can be seen that a control unit 20 for the laser 18 can be provided next to the laser 18, enabling it to emit pulsed laser pulses, for example, in a predefined pattern to generate the interfaces 14 and 16.Alternatively, the control unit 20 can be an external control unit 20 with respect to the treatment device 10.

[0063] Furthermore, the Fig. 1, that the laser beam 24 generated by the laser 18 is deflected towards the cornea 26 by means of a beam deflection device 22, namely a beam deflection device, such as a rotary scanner. The beam deflection device 22 is also controlled by the control device 20 in order to generate the interfaces 14, 16, preferably also incisions or cuts, along predetermined incision paths.

[0064] The laser 18 shown is preferably a photodisruptive and / or ablative laser configured to emit laser pulses in a wavelength range between 300 nm and 1400 nm, preferably between 700 nm and 1200 nm, with a pulse duration between 1 fs and 1 ns, preferably between 10 fs and 10 ps, ​​and a repetition frequency greater than 10 kHz, preferably between 100 kHz and 100 MHz. The control device 20 optionally also includes a storage device (not shown) for at least temporarily storing at least one control data set, wherein the control data set(s) comprise control data for positioning and / or focusing individual laser pulses in the cornea.The position data and / or focusing data of the individual laser pulses, that is, the lenticule geometry of the lenticule 12 to be separated, is generated on the basis of predetermined control data, in particular from a previously measured topography and / or pachymetry and / or the morphology of the cornea or the optical refractive error correction to be produced.

[0065] To determine refractive error data, which can specify a value in diopters, for example, suitable examination data for describing the refractive error can be received from a data server by the control unit 20, or the examination data can be entered directly into the control unit 20.

[0066] The planning of the correction to be achieved and thus the geometry of the lenticule 12 to be removed is usually carried out according to standard methods, whereby a refractive power correction and / or a lenticule diameter is planned, and the anterior and posterior interface 14, 16 of the lenticule 12 are then determined from this.

[0067] To remove the detached lenticule 12 from the corneal volume 26, an incision or cut can be made using the laser 18, as described above. In the present embodiment, exactly one incision 15 is provided. The incision path 17, i.e., the geometry and position of the incision, can also be included in the control data.

[0068] The incision 15 comprises a predetermined incision path 17, extending from the outer surface, i.e., the anterior corneal surface 30, to the respective interface 14, 16. As in Fig. As shown in Figure 1, incision 15 is designed as a dual or multiple incision 15. This means that several levels or areas within the cornea 26 can be accessed through a single incision. Compared to two separate incisions, one for each of the interfaces 14, 16, this offers the advantage of avoiding alteration or damage to the cornea 26 and thus preventing additional effects that could impact refractive error. For example, unnecessary weakening of corneal biomechanics or the additional induction of refractive defects or aberrations, such as astigmatism or coma, can be reduced. Furthermore, it prevents additional damage to the tissue and / or changes in shape. The integrity of the cornea 26 can therefore be preserved to the greatest extent possible through the multiple incision.The strain on the eye for accessing the respective plane, i.e., the respective interface 14, 16, can be minimized.

[0069] To create the multiple incision 15, the incision path 17 divides starting from the anterior corneal surface 30. That is, the incision path branches out. The incision path 17 extends on one side to the first interface 14 and on the other side to the second interface 16. Due to this division, the incision path 17 thus comprises at least three sections or segments, which are referred to below as pathways.

[0070] A first incision path 17a extends from the anterior corneal surface 30 into the corneal volume 26. At one end, the first incision path 17a intersects the anterior corneal surface 30 at an incision 30a. At the opposite end, the first incision path 17a is bounded by a node 17d. From node 17d, the incision path 17 divides into a second incision path 17b and a third incision path 17c.

[0071] The second path 17b extends from node 17d to the first interface 14. The third path 17c extends from node 17d to the second interface 16. The second path 17b is thus bounded at one end by node 17d and at the other end by an interface 14a with the first interface 14. Similarly, the third path is bounded at one end by node 17d and at the other end by an interface 16a with the second interface 16.

[0072] In the exemplary embodiment in Fig. The three pathways 17a, 17b, 17c are essentially straight lines. The straight path has the advantage that guiding the removal of the lenticel by inserting it into the incision 15 is particularly easy. Alternatively, the pathways 17a, 17b, 17c could, for example, have a curved path and thus describe a curve.

[0073] The incision line 17 shows, according to the in Fig. The two-dimensional representation shown in Figure 1 has a Y-shape or the shape of a snake's tongue. This means that the second and third pathways 17b and 17c exhibit a change of direction relative to the first pathway 17a. Relative to a reference plane, for example the anterior corneal surface 30, the three pathways 17a, 17b, and 17c thus run in different directions.

[0074] Of course, there are others besides the one in Fig. The incision pattern shown is 17 possible. Fig. Figures 2 to 4 show further examples of possible incision patterns. 17. For clarity, the following is shown in the Fig. Figures 2 to 4 show only the incision path 17 without the cornea 26. In the figures, the respective incision path is again shown two-dimensionally, in particular in a cross-sectional view that results when the cornea 26 is cut along the optical axis.

[0075] In the Fig. 2 to 4 are the routes 17a, 17b, 17c analogous to the embodiment shown in the Fig. 1 is represented as a straight line. Of course, each of the paths 17a, 17b, 17c, for example, can have a curved path, as mentioned before, and thus follow a predetermined trajectory.

[0076] According to the embodiment in Fig. 2. The incision path 17 has a stair-like or stepped shape. Furthermore, the second path 17b exhibits a change of direction both internally and relative to the first path. The third path 17c, however, does not exhibit a change of direction and runs in the same direction as the first path 17a. The third path 17c thus extends the path 17a.

[0077] To achieve the change of direction, the second route path 17b is divided into two sections 17b' and 17b". Section 17b' runs from junction 17d, for example, perpendicular to routes 17a and 17c. The second section 17b" is connected to section 17b' at the end opposite junction 17d. Section 17b" runs, for example, perpendicular to section 17b' and thus parallel to route path 17c.

[0078] In Fig. Section 17b and the incision path 17c have different lengths. This difference in length is shown here as an example to symbolize different geometries of the incision path. It should be noted that the shape and geometry of the incision path 17, in particular the paths 17a to 17c and / or their sections, can be chosen depending on the geometry of the cornea 26 and the lenticule 18. The geometry can refer, for example, to the length, width, or thickness, or the angle that the paths 17a to 17c and / or their sections form with each other, or to the course of the paths 17a to 17c relative to each other.

[0079] According to the embodiment in Fig. In the third incision path 17, the incision path has a branched form. The third path 17c includes a change of direction. For this purpose, the third path 17c is divided into two sections 17c' and 17c". Section 17c runs from the node 17d in the same direction as the first path 17a. That is, section 17c' extends the first path 17a. Section 17c" connects to the end of section 17c' opposite node 17d. In this example, section 17c" runs at an angle of approximately 120 degrees to section 17c'.

[0080] The second route path 17b runs from junction 17d parallel to the second section 17c. That is, the second route path 17b runs at approximately an angle of 120 degrees to the first route path 17a.

[0081] In the exemplary embodiment in Fig. The first route path 17a also exhibits a change of direction. Accordingly, the first route path 17a is also divided into two sections 17a' and 17a". Section 17a' runs from junction 17d in the same direction as section 17c'. Section 17a" connects to the end of section 17a' opposite junction 17d. Section 17a" runs parallel to the second route path 17b and section 17c". However, section 17a" runs in the opposite direction to section 17c" and the second route path 17b.

[0082] According to the embodiment in Fig. 4. The incision path 17 forms a fork shape. The second and third paths 17b and 17c involve a change of direction. Each path 17b and 17c is composed of two sections 17b', 17b", 17c', and 17c". Starting from the node, sections 17b' and 17c' run perpendicular to the direction of the first path 17a. Sections 17b" and 17c" connect to the ends of sections 17c' and 17b' opposite node 17d and run perpendicular to sections 17b' and 17c'. That is, sections 17b" and 17c" run essentially parallel to the first path 17a.

[0083] As in Fig. As shown in Figure 4, the first path 17a can be inclined relative to the paths of sections 17b' and 17c'. In this case, for example, the inclined first path 17a' can form an angle of approximately 70 degrees with section 17c'.

[0084] Of course, other forms besides those in the Fig. Figures 1 to 4 are provided for the incision path 17. For example, any combination of the illustrated embodiments can be implemented. In the Fig. In sections 2 to 4, the paths 17a, 17b, and 17c run essentially parallel to each other, at least in certain segments. Alternatively, for example, a non-parallel alignment or an asynchronous course of the paths 17a to 17c could be provided.

[0085] The geometry, position, or orientation of the incision path 17 in the cornea 26 can, for example, be selected depending on a corneal structure. For instance, the second and / or third path can run, at least partially, preferably substantially parallel to one of several tissue layers of the cornea 26 that run parallel to the anterior corneal surface 30. These tissue layers are known as fibrils. The course of the tissue layers, i.e., the structure of the cornea 26, can be known from the previously described measured topography and / or perimetry and / or the morphology of the cornea 26. Accordingly, the first path 17a can run, at least partially, preferably substantially perpendicular to the anterior corneal surface 30.

[0086] This allows the cornea 26 to be cut perpendicularly using the laser, starting from the anterior corneal surface 30 and extending to the node point. From the node point onward, an attempt can be made to follow the course of the fibrils and thus cut between two adjacent tissue layers. This ensures that the smallest possible area of ​​tissue is damaged. In this way, the healing process can be accelerated and irritation for the patient reduced.

[0087] In Fig. Figure 5 shows a schematic process flow diagram for providing control data for the laser 18 of the treatment device 10 for corneal correction 26. The diagram includes... Fig. 5. By way of example, only the procedure steps for introducing the incision line 17 into the cornea 26 are described. The introduction of the interfaces 14, 16 is known per se.

[0088] In the procedure, in step S1, the first and second interfaces 14, 16 are first determined as cross-sectional surfaces in the cornea 26 of the eye. The primary aim is to capture or measure the geometry and position of the interfaces 14, 16, in this case, in particular the lenticule geometry. This can, for example, be known from the measurements described previously.

[0089] Subsequently, in step S2, the incision path 17 is defined. As mentioned previously, this begins on the outer surface, i.e., on the anterior corneal surface 30, and ends at various points on one of the interfaces 14, 16. In particular, step S2 is therefore about defining the shape, i.e., the course or geometry and the position of the incision path 17. As described previously, this can be done depending on the lenticule geometry and also on the corneal structure.

[0090] In step S3, the control data for controlling the laser 18, which at least includes the defined incision path 17, are finally provided.

[0091] The described procedure can be carried out, for example, using the control unit 20. That is, the control unit 20 can provide the control data to the laser 18.

[0092] Overall, the examples show how the invention can provide a dual incision by means of which multiple levels in a cornea 26 can be achieved for refractive error correction.

Claims

[1] Method for providing control data for an ophthalmic surgical laser (18) of a treatment device (10), the method comprising the following steps performed by means of a control device (20): - Determining a first and at least a second cross-sectional surface (14, 16) in a cornea (26) of a human or animal eye, - Establishing an incision path which, starting from an outer surface of the cornea (26), divides and extends on the one hand to the first cutting surface (14) and on the other hand to at least the second cutting surface (16), - wherein the incision path has a first path (17a) extending from the outside into a volume of the cornea (26), and which splits at a node (17d) into a second path (17b) and at least a third path (17c), wherein the second path (17b) extends from the node (17d) to the first cut surface (14) and the at least third path (17c) extends from the node (17d) to the at least second cut surface (16), - Providing control data for controlling the ophthalmic surgical laser (18), which includes at least the specified incision path, characterized by , that - the second and third routes (17c) enclose an angle between 70 and 120 degrees at the node. [2] Method according to claim 1 wherein, starting from a direction of travel and / or a radius of curvature of the first path (17a), the second and / or the at least third path (17b, 17c) have a change of direction in their respective direction of travel. [3] Method according to claim 1 or 2, wherein the paths are essentially straight lines. [4] Method according to one of the preceding claims, wherein at least the first path (17a) has at least one change of direction in its direction of travel. [5] Method according to one of the preceding claims, wherein the second path (17b) or the at least third path (17c) has at least one change of direction in its respective direction of travel. [6] Method according to one of the preceding claims, wherein the second path (17b) and the at least third path (17c) have at least one change of direction in their respective directions. [7] Method according to one of the preceding claims, wherein the second path (17b) and the at least third path (17c) run parallel to each other at least section by section. [8] Method according to one of the preceding claims, wherein the second and / or the at least third pathway (17b, 17c) runs at least section-wise, preferably substantially parallel to one of several tissue layers of the cornea (26) running parallel to the outside. [9] Method according to one of the preceding claims, wherein the laser (18) is controlled by providing the control data by means of the control device (20) to emit laser pulses in a wavelength range between 300 nm and 1400 nm, preferably between 700 nm and 1200 nm, at a respective pulse duration between 1 fs and 1 ns, preferably between 10 fs and 10 ps, ​​and a repetition frequency greater than 10 kHz, preferably between 100 kHz and 100 MHz. [10] Method for controlling a treatment device (10) wherein the method comprises the following steps: - the process steps of a process according to one of the preceding claims, and - Transferring the provided control data to a respective ophthalmic surgical laser (18) of the treatment device (10). [11] Control device (20) configured to carry out a respective procedure according to one of the preceding claims. [12] Treatment device (10) comprising at least one ophthalmic surgical laser (18) for introducing predefined cut surfaces (14, 16) into a cornea (26) of a human or animal eye by means of optical breakthrough, in particular by means of ablation and / or photodisruption, and at least one control device (20) according to claim 11. [13] Computer program comprising commands that cause the treatment device (10) according to claim 12 to perform a method according to any one of claims 1 to 9 and / or a method according to claim 10. [14] Computer-readable medium on which a computer program according to claim 13 is stored.

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