Method for optimizing laser parameters for an ophthalmic laser of a treatment device

Abstract

Method for optimizing laser parameters for an ophthalmic laser (12) of a treatment device (10), wherein the method comprises the following steps performed by means of a control device (18): - Determine (S12) whether a treatment quality with the treatment device (10) performed with first laser parameters (S10) corresponds to a predetermined treatment quality criterion, wherein the laser parameters include at least a laser pulse energy, a spatial laser pulse spacing and a spatial laser pulse path spacing; - if the treatment quality does not meet the treatment quality criterion, provide a second laser parameter (S14) in which at least one laser parameter is adjusted by a predetermined value; - wherein the second laser parameters are used for subsequent treatment with the treatment device (10) (S16); - where the treatment quality criterion includes at least one of the following aspects: ◯ the formation of an opaque blister layer in a treatment area; ◯ the formation of black spots in the treatment area; ◯ a separation result, which is determined in particular by the required dissection time of irradiated tissue; ◯ a recovery outcome, determined in particular by an inflammatory response and / or achieved visual acuity; - wherein a grade is determined for the respective aspect of the treatment quality criterion, wherein the respective aspect is divided into a severe, medium and mild grade, wherein in a severe grade all three laser parameters are adjusted, wherein in a medium grade two laser parameters are adjusted, and wherein in a mild grade one of the laser parameters is adjusted.

Description

[0001] The invention relates to a method for optimizing laser parameters for an ophthalmic laser of a treatment device. Furthermore, the invention relates to a control unit configured to carry out the method, a treatment device with such a control unit, a computer program comprising commands that cause the treatment device to execute the method, and a computer-readable medium on which the computer program is stored.

[0002] Treatment devices and methods for controlling ophthalmic lasers to correct refractive errors and / or pathologically or abnormally altered areas of the cornea are known in the prior art. For example, pulsed lasers and a beam focusing device can be configured such that laser pulses cause photodisruption and / or ablation in a focus located within the organic tissue in order to remove tissue, in particular a tissue lenticel, from the cornea.

[0003] Treatment devices typically allow for free adjustment of the laser pulse energy, the spatial laser pulse spacing within the cornea, and the spatial laser pulse path spacing between adjacent laser pulse paths within the cornea. The quality of the resulting incisions and / or ablations of corneal tissue depends on the appropriate selection of these laser parameters. However, the appropriate selection of these laser parameters, and thus the quality of the incisions, can also depend on the location of the treatment device, particularly environmental conditions, and / or other parameters. Therefore, it is often unclear which laser parameters are most suitable for a given treatment device and / or whether the laser parameters need to be adjusted over time.

[0004] US Patent 2011 / 0251601 A1 discloses an ophthalmic laser system and an operating procedure. The cornea is irradiated with an ophthalmic laser, and a detection light is measured confocally. The cornea is scanned in three dimensions by irradiating it with a specific laser intensity along multiple directions at several points using a scanner unit. By simultaneously recording the detection light, the position and / or shape of a posterior corneal interface is determined. A flap parallel to the posterior interface can then be cut.

[0005] A method for irradiation in ophthalmology is known from DE 103 05 063 A1. In this method, the fundus images acquired by an image acquisition unit during treatment and the beam parameters emitted by an irradiation unit are stored by a central control unit after the positions of the irradiation sites have been determined. These images are then combined with previous fundus images and beam parameters to create a resulting fundus image that includes all irradiation sites and their respective individual irradiation parameters. This image is displayed on a monitor and / or in an eyepiece. The use of low-energy laser sources limits the coagulation effect to the immediate irradiation sites and prevents damage to adjacent tissue layers.By recording the treatments performed so far, including irradiation locations and parameters, and the results achieved, a simple and safe determination of the further course of treatment and healing can be made.

[0006] Methods for testing a laser device are known from EP 2 621 661 B1 and eye coverings for corneal healing and methods of use are known from US 2014 / 0155800 A1.

[0007] The object of the invention is to optimize laser parameters for an ophthalmic laser of a treatment device.

[0008] This problem is solved by the independent patent claims. Advantageous embodiments of the invention are disclosed in the dependent patent claims, in the following description, and in the figures.

[0009] The invention is based on the idea that at least one treatment, preferably several treatments, is performed with the treatment device, whereby the treatment quality or treatment result is automatically or manually fed back in order to adjust the laser parameters accordingly. That is, control of the laser parameters based on at least one previously performed treatment can be provided.

[0010] One aspect of the invention relates to a method for optimizing laser parameters for an ophthalmic laser of a treatment device, wherein the method comprises the following steps, which are carried out by means of a control device. A control device is understood to be a device or device component, in particular a computer or processor, which can perform the following steps automatically or semi-automatically.

[0011] A determination is made as to whether the treatment quality achieved with the treatment device, using initial laser parameters, meets a predefined treatment quality criterion. The laser parameters include at least a laser pulse energy, a spatial laser pulse spacing, and a spatial laser pulse path spacing. If the treatment quality does not meet the treatment quality criterion, a second set of laser parameters is provided, in which at least one laser parameter is adjusted by a predefined value, particularly depending on the treatment quality criterion. These second laser parameters are then used for a subsequent treatment with the same device.

[0012] In other words, treatment can initially be performed using the treatment device, which has the first laser parameters. These laser parameters can include at least a laser pulse energy, a distance between adjacent laser pulses, or a distance between adjacent laser pulse paths. The treatment can be performed, for example, as part of a refractive correction of a patient's cornea.

[0013] After this treatment has been performed, it can be verified whether the treatment quality meets a predefined treatment quality criterion. Treatment quality can be determined automatically, for example, using a detection device such as a camera, or it can be determined by a user, particularly a physician, who can provide the results of an evaluation of the control unit. Treatment quality can include, for example, the quality of the cut, meaning the success of tissue separation; the formation of an opaque blister layer, which occurs particularly with excessive energy deposition in the tissue; or the formation of black spots, which occur with insufficient energy deposition in the tissue.Thus, the treatment quality criterion allows for the evaluation of various aspects of treatment quality, enabling a decision on whether or not the laser parameters should be adjusted. The treatment quality criterion can be a condition or requirement against which treatment quality is assessed.

[0014] If it is determined that the treatment quality does not meet the treatment quality criterion, the first laser parameters can be adjusted, thereby providing second laser parameters. For the second laser parameters, at least one of the first laser parameters can be changed by a predetermined value, particularly depending on the treatment quality and / or the treatment quality criterion. This means that either the laser pulse energy, the spatial pulse spacing, or the spatial laser pulse path spacing can be changed, or several of the aforementioned laser parameters. It is particularly preferred that these parameters are changed by a predetermined value, which is specified in such a way that the corresponding laser parameters change in small increments until the treatment quality criterion is met.

[0015] In particular, the second laser parameters can be used for subsequent treatment with the treatment device. This means that the treatment device can be controlled by the control unit using the second laser parameters. The procedure can preferably be carried out iteratively, meaning that after the second laser parameters have been provided, it can be checked again whether the treatment quality meets the treatment quality criterion, and then the second laser pulse parameters can be adjusted again. This means that when the procedure is repeated, the second laser parameters become the first laser parameters, and it can be checked again whether the treatment quality criterion is met.

[0016] The invention offers the advantage that the laser parameters can be continuously optimized, particularly independently of the location and / or environmental conditions of the treatment device.

[0017] Furthermore, according to the invention, the treatment quality criterion comprises at least one of the following aspects: It can verify the formation of an opaque blister layer in a treatment area, the formation of black spots in the treatment area, a separation result, which is determined in particular by the required dissection time of irradiated tissue, and / or a recovery result, which is determined in particular by an inflammatory reaction and by the achieved visual acuity. In other words, the treatment criterion can verify whether an opaque blister layer forms in a treatment area. An opaque blister layer can occur if there is excessive energy deposition in tissue of the treatment area, as excess energy enters the tissue and structurally alters and clouds it.This can be determined, for example, using a detection device, particularly a camera. Alternatively or additionally, it can be checked whether black spots appear in the treatment area. Black spots can occur, for example, if the energy deposition in the tissue of the treatment area is insufficient to separate the tissue, causing it to change and turn black. The formation of black spots can also be detected by a detection device. Alternatively or additionally, the treatment quality criterion can be used to check the separation result, i.e., the quality of the laser cut in the treatment area. In particular, it can be determined how quickly the irradiated tissue detaches from the surrounding cornea, or how quickly it can be detached, which can be provided as the dissection time.Alternatively or additionally, the treatment quality criterion can be used to assess the recovery outcome. This means that it can be determined how well a patient tolerates treatment with the device that has the initial laser parameters. In particular, an inflammatory reaction in the eye or cornea can be determined, for example, by a physician who can enter the results into the control unit. The achieved visual acuity, i.e., any visual impairment after treatment, can also be used to determine the recovery outcome. In other words, the recovery outcome can determine how quickly an eye recovers after treatment.

[0018] Furthermore, it is planned that a grade will be determined for each aspect of the treatment quality criterion, with each aspect being classified as severe, moderate, or mild. In a severe grade, all three laser parameters are adjusted; in a moderate grade, two laser parameters are adjusted; and in a mild grade, one laser parameter is adjusted. In other words, the severity of the impact on each aspect of the treatment quality criterion can be categorized. An aspect of the treatment quality criterion refers to one of the aforementioned properties; for example, an aspect of the treatment quality criterion could include the formation of the opaque blister layer, the formation of black dots, the separation result, and / or the recovery result.These can each be classified into one of at least three predefined grades, in particular severe, moderate, and mild. For example, in the case of an opaque blister layer, it can be determined how many opaque areas develop in the cornea, and this can then be used to classify the grade. Thus, depending on the grade of the opaque blister layer, the black spots, the separation result, and / or the patient's recovery, one to three laser parameters, in particular the laser pulse energy, the spatial laser pulse spacing, and / or the spatial laser pulse path spacing, can be adjusted accordingly.For example, in the case of an opaque blister layer classified as severe, the laser pulse energy can be reduced by 5 nJ, the laser pulse spacing increased by 0.1 µm, and the laser pulse path spacing increased by 0.2 µm. Similarly, in the case of a moderate degree of blister layer, the laser pulse energy can be reduced by 5 nJ and, for instance, the laser pulse path spacing increased by 0.2 µm. Finally, in the case of a mild degree of blister layer, only the laser pulse energy can be reduced by 5 nJ. This approach offers the advantage of achieving optimized laser parameters more quickly, depending on the degree of blister layer.

[0019] The invention also includes further developments that result in additional advantages.

[0020] Further training stipulates that the treatment quality criterion includes the formation of an opaque blister layer in a treatment area. If an opaque blister layer forms, the laser pulse energy is reduced and / or the spatial pulse spacing and / or the spatial laser pulse path spacing is increased to provide the necessary second laser parameters for the subsequent treatment. In other words, if an opaque blister layer forms in the treatment area when using the first laser parameters, the laser pulse parameters can be adjusted to reduce the result of the formula "laser pulse energy / (laser pulse spacing * laser pulse path spacing)." This has the advantage of preventing or reducing the formation of an opaque blister layer for subsequent treatments.

[0021] Further training stipulates that the treatment quality criterion includes the formation of an opaque bubble layer in a treatment area. If this opaque bubble layer fails to form, the laser pulse energy is increased and / or the spatial laser pulse spacing and / or the spatial laser pulse path spacing are reduced to provide the necessary second laser parameters for the subsequent treatment. In other words, if the first laser parameters do not generate an opaque bubble layer, the energy deposition in the treatment area can be increased to achieve, for example, an improved separation result. Specifically, the result of the formula "laser pulse energy / (laser pulse spacing * laser pulse path spacing)" can be increased. This offers the advantage of iteratively approximating an optimized threshold between the formation of an opaque bubble layer and an improved separation result.

[0022] Further training stipulates that the treatment quality criterion includes the formation of black spots in a treatment area. If black spots occur, the laser pulse energy is increased and / or the spatial laser pulse spacing and / or the spatial laser pulse path spacing are reduced to provide the second laser parameters for the subsequent treatment. In other words, the treatment quality criterion can be used to check for the formation of black spots, increasing energy deposition in the treatment area if black spots appear. Specifically, the result of the formula "laser pulse energy / (laser pulse spacing * laser pulse path spacing)" can be increased. This has the advantage of preventing or reducing the formation of black spots.

[0023] Preferably, the formation of the opaque blister layer and / or the black spots in the treatment area is detected by a camera system. This means, for example, that the treatment device can use a camera system comprising one or more cameras for monitoring the treatment area in order to detect changes in the tissue, in particular the formation of an opaque blister layer and / or black spots. The camera can, for example, record data in the visual or infrared spectral range. This offers the advantage that the treatment quality criterion can be monitored during treatment with the device.

[0024] Further training stipulates that the treatment quality criterion includes a separation result. If the separation result is rated as unsatisfactory, the laser pulse energy is increased and / or the spatial laser pulse spacing and / or the spatial laser pulse path spacing is reduced to provide the necessary second laser parameters for the subsequent treatment. In other words, the treatment quality criterion allows for the verification of a separation result. This separation result can be evaluated, for example, according to a predefined scale that at least distinguishes between a deficient and a satisfactory or good treatment. Preferably, further evaluation levels, for example, in the form of a school grading system, can be provided.If the separation result is deemed unsatisfactory, the energy deposition in the tissue of the treatment area can be increased for subsequent treatments. Specifically, the result can be calculated using the formula "laser pulse energy / (laser pulse interval * laser pulse path spacing)." Preferably, the separation result can be entered by a user, such as a physician, via an input device, allowing them to review and evaluate the result. This offers the advantage of continuously adjusting and improving tissue separation.

[0025] Further development stipulates that the treatment quality criterion includes a recovery outcome assessment. If the recovery outcome is rated as unsatisfactory, the laser pulse energy is reduced and / or the spatial laser pulse spacing and / or the spatial laser pulse path spacing are increased to provide the necessary second laser parameters for subsequent treatment. This means that the treatment quality criterion allows for the evaluation of a recovery outcome or patient recovery, and if this is unsatisfactory, energy deposition in the tissue of the treatment area can be reduced. In particular, a result calculated using the formula "laser pulse energy / (laser pulse spacing * laser pulse path spacing)" can be reduced. Preferably, the recovery outcome can be entered by a user, such as a physician, via an input device, who can then review and evaluate the recovery outcome.This offers the advantage that treatment can be continuously adapted and improved.

[0026] Further training stipulates that the laser pulse energy is adjusted to a predefined value of 5 nJ, and / or the spatial laser pulse spacing is adjusted to a predefined value of 0.1 µm, and / or the spatial laser pulse path spacing is adjusted to a predefined value of 0.2 µm. Here, "adjust" means that the respective laser parameter can be increased or decreased by this value, depending on which treatment quality criterion is not met. These predefined values ​​represent suitable adjustment options, particularly for iterative adjustment of the laser parameters, as they provide a change that is not so large as to produce other detrimental effects.

[0027] Further development involves setting predefined limits for each laser parameter, which must not be exceeded when adjusting the laser parameters. Specifically, these limits include 60 nJ as the lower limit and 300 nJ as the upper limit for the laser pulse energy, 1.5 µm as the lower limit and 18 µm as the upper limit for the spatial laser pulse spacing, and 0.5 µm as the lower limit and 10 µm as the upper limit for the spatial laser pulse path spacing. In other words, the ranges within which the laser parameters can be changed can be limited by predefined limits. These limits can be set in such a way that the laser parameters do not fall outside the safety regulations or the limits of the treatment device.

[0028] Further training involves adjusting the laser parameters depending on the treatment area where a reduction in treatment quality has been observed. In other words, the laser parameters can be adjusted differently for different treatment areas or positions on the cornea. For example, the laser parameters can be adjusted only in a peripheral area of ​​the treatment or in a central area. Thus, laser parameters that are optimized for the entire treatment can be adjusted only where a reduction in quality occurs.This can occur particularly when an opaque bubble layer forms, especially at the beginning of treatment in a peripheral area. After the initial cavitation bubble path is formed, sufficient space is available to dissipate excess energy, allowing for different laser parameters in more central treatment areas. This offers the advantage of improved treatment outcomes.

[0029] Further training involves verifying the treatment quality for a predetermined number of treatments using the initial laser parameters before the second set of laser parameters is implemented. In other words, the laser parameters are not adjusted after each treatment, but rather after a specified number of treatments. Specifically, the laser parameters may be adjusted after at least two, preferably more, treatments, for example, five or ten treatments. It is particularly advantageous to compile statistics from all previously performed treatments to assess the treatment quality using the treatment quality criterion. This offers the advantage of enabling further improvement and optimization of the laser parameters.

[0030] 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 a method as previously described. Furthermore, the method for controlling the treatment device includes the step of transmitting the provided second laser parameters to at least one ophthalmic laser of the treatment device and controlling the treatment device and / or the laser with the second laser parameters and / or by means of control data. The control data may include a data set for positioning and / or focusing individual laser pulses in the cornea. The control data may additionally or alternatively include a data set for adjusting 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.

[0031] 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.

[0032] 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.

[0033] 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 a predefined corneal volume with predefined interfaces of a human or animal eye by means of optical breakthrough, in particular to at least partially separate it by means of photodisruption, and / or to ablate corneal layers by means of (photo)ablation, and / or to cause a laser-induced change in the refractive index of the cornea and / or the lens of the eye, and / or to increase corneal crosslinking.

[0034] In a further advantageous embodiment of the treatment device according to the invention, the laser can be 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 subsumed under the term "deep ultraviolet" in laser technology. 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. 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.

[0035] In a further advantageous embodiment of the treatment device according to the invention, the control device can have at least one storage device for at least temporary storage of 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; and can have 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 laser.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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 forth in the cross-references of the claims, are also to be considered disclosed. For exemplary embodiments, see: Fig. 1 a schematic representation of a treatment device according to an exemplary embodiment; Fig. 2 a schematic process diagram according to an exemplary embodiment.

[0040] In the figures, identical or functionally equivalent elements are provided with the same reference symbols.

[0041] The Fig. Figure 1 shows a schematic representation of a treatment device 10 with an ophthalmic laser 12 for the removal of tissue 14 from a human or animal cornea 16 by means of photodisruption and / or ablation. The tissue 14 can, for example, be a lenticule or a volumetric body that can be removed from the cornea 16 with the ophthalmic laser 12 to correct a refractive error. A correction profile or a geometry of the tissue 14 to be removed can be provided by a control unit 18, in particular in the form of control data, so that the laser 12 emits pulsed laser pulses into the cornea 16 of the eye in a pattern predefined by the control data in order to remove the tissue 14.For this purpose, the control unit 18 can also provide laser parameters that define at least a laser pulse energy, a spatial laser pulse spacing, and a spatial laser pulse path spacing. Alternatively, the control unit 18 can be an external control unit 18 with respect to the treatment device 10.

[0042] Furthermore, the Fig. 1. The laser beam 20 generated by the laser 12 can be deflected towards the cornea 16 by means of a beam deflection device 22, such as a rotary scanner, in order to remove the tissue 14. The beam deflection device 22 can also be controlled by the control device 18 to remove the tissue 14.

[0043] The laser 12 shown is preferably a photodisruptive and / or photoablative laser configured to emit laser pulses in a wavelength range between 300 nanometers and 1400 nanometers, preferably between 700 nanometers and 1200 nanometers, with a pulse duration between 1 femtosecond and 1 nanosecond, preferably between 10 femtoseconds and 10 picoseconds, and a repetition frequency greater than 10 kilohertz, preferably between 100 kilohertz and 100 megahertz. The control device 18 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.

[0044] Furthermore, the Fig. 1. A camera device 24, which may be configured to monitor a treatment area of ​​the cornea 16. The camera device 24 may, for example, be part of the treatment device 10 or be provided separately. The data that can be recorded by the camera device 24 may be provided to the control device 18, in particular for checking treatment quality.

[0045] The review of treatment quality can, for example, be used to appropriately adjust or optimize the laser parameters of the treatment device 10 in order to improve the treatment outcome. This can be achieved by the in Fig. The two procedures shown will be carried out.

[0046] The Fig.Figure 2 shows a process diagram for optimizing laser parameters for an ophthalmic laser 12 of a treatment device 10. In a step S10, a treatment can be performed with the treatment device 10, wherein the laser 12 and / or the beam deflection device 22 can be controlled with first laser parameters that include at least a laser pulse energy, a spatial laser pulse spacing and a spatial laser pulse path spacing.

[0047] In step S12, the treatment quality of the procedure performed with the initial laser parameters can then be verified. For this purpose, for example, the incisions made in the cornea 16 to separate the tissue 14 can be recorded using a camera device 24, and these can then be examined by the control unit 18 for the presence of one or more treatment quality criteria. Alternatively or additionally, the treatment quality criterion can also be verified by a user, such as a physician, whereby the results of this verification, such as an evaluation of the incisions and / or the patient's or corneal 16's recovery, can be made available to the control unit 18 via a user interface (not shown).

[0048] The treatment quality criterion that can be used to verify treatment quality can include at least one, preferably several, of the following aspects: The formation of an opaque blister layer in the cornea 16 can be checked; the formation of black spots in the cornea 16 can be checked; the separation result of cut surfaces of the volume body 14 can be checked; and / or the recovery result, i.e., for example, inflammatory reactions after treatment, can be checked.

[0049] In step S14, the first laser parameters can be adjusted to second laser parameters, in which at least the laser pulse energy and / or the spatial laser pulse spacing and / or the spatial laser pulse path spacing can be adjusted by a predetermined value compared to the first laser parameters if the treatment quality does not meet the treatment quality criterion.

[0050] For example, it may be observed that an opaque blister layer forms in the cornea, in which case the laser pulse energy can be reduced. Alternatively or additionally, the spatial laser pulse spacing and / or the spatial laser pulse path spacing can be increased. If, however, no opaque blister layer forms and the treatment quality still does not meet the treatment quality criteria, the laser pulse energy can be increased and / or the spacing can be reduced to improve tissue separation.

[0051] Alternatively or additionally, it can be checked whether black spots appear in the treatment area of ​​the cornea 16 when irradiated with the first laser parameters, in which case the laser pulse energy can be increased and / or the laser pulse intervals can be reduced.

[0052] Alternatively or additionally, a separation result can be checked, for example whether the volume body 14 can be removed from the cornea 16 without difficulty or not, whereby, if the separation result is assessed as inadequate, the laser pulse energy can be increased and / or the spatial laser pulse spacing or the spatial laser pulse path spacing can be reduced for a subsequent treatment.

[0053] In particular, it can be provided that, for increasing or decreasing the laser parameters to provide the second laser parameters, a laser pulse energy is increased or decreased by a predetermined value of 5 nJ, and / or the spatial laser pulse spacing is increased or decreased by a predetermined value of 0.1 µm, and / or the spatial laser pulse path spacing is increased or decreased by a predetermined value of 0.2 µm. Preferably, it can be provided that the laser pulse energy values ​​are not adjusted below 60 nJ and above 300 nJ, the laser pulse spacing is not adjusted below 1.5 µm and above 18 µm, and the laser pulse path spacing is not adjusted below 0.5 µm and above 10 µm.

[0054] Furthermore, the treatment quality criterion can be used to assess the extent or degree of each of the aforementioned effects in the cornea 16. Preferably, these can be subdivided into at least severe, moderate, and mild degrees. If a severe degree is determined, the laser pulse energy, the spatial laser pulse spacing, and the spatial laser pulse path spacing can be adjusted simultaneously. In the case of a moderate degree, two laser parameters can be adjusted, and in the case of a mild degree, only one of the laser parameters can be adjusted.

[0055] In step S16, the second laser parameters for a subsequent treatment with the treatment device 10 can be set, and the laser can be controlled using these parameters. Preferably, the process can then be repeated iteratively, as indicated by the dashed line between step S16 and step S10. This allows for continuous optimization of the laser parameters. Preferably, the laser parameters are not set after each treatment; instead, it is checked after a predetermined number of treatments whether an adjustment is necessary. In particular, statistics can be compiled from the treatments performed to verify compliance with the treatment quality criterion.

[0056] Overall, the examples show how automatic optimization of laser parameters can be achieved.

Claims

[1] Method for optimizing laser parameters for an ophthalmic laser (12) of a treatment device (10), wherein the method comprises the following steps performed by means of a control device (18): - Determine (S12) whether a treatment quality with the treatment device (10) performed with first laser parameters (S10) corresponds to a predetermined treatment quality criterion, wherein the laser parameters include at least a laser pulse energy, a spatial laser pulse spacing and a spatial laser pulse path spacing; - if the treatment quality does not meet the treatment quality criterion, provide a second laser parameter (S14) in which at least one laser parameter is adjusted by a predetermined value; - wherein the second laser parameters are used for subsequent treatment with the treatment device (10) (S16); - where the treatment quality criterion includes at least one of the following aspects: ◯ the formation of an opaque blister layer in a treatment area; ◯ the formation of black spots in the treatment area; ◯ a separation result, which is determined in particular by the required dissection time of irradiated tissue; ◯ a recovery outcome, determined in particular by an inflammatory response and / or achieved visual acuity; - wherein a grade is determined for the respective aspect of the treatment quality criterion, wherein the respective aspect is divided into a severe, medium and mild grade, wherein in a severe grade all three laser parameters are adjusted, wherein in a medium grade two laser parameters are adjusted, and wherein in a mild grade one of the laser parameters is adjusted. [2] Method according to claim 1, wherein the treatment quality criterion comprises the formation of an opaque blister layer in a treatment area, wherein, in the event of the formation of the opaque blister layer, the laser pulse energy is reduced and / or the spatial laser pulse spacing and / or the spatial laser pulse path spacing is increased in order to provide the second laser parameters for the subsequent treatment. [3] Method according to one of the preceding claims, wherein the treatment quality criterion comprises the formation of an opaque blister layer in a treatment area, wherein, if the opaque blister layer fails to form, the laser pulse energy is increased to provide the second laser parameters for the subsequent treatment and / or wherein the spatial laser pulse spacing and / or the spatial laser pulse path spacing is reduced. [4] Method according to one of the preceding claims, wherein the treatment quality criterion comprises the formation of black spots in a treatment area, wherein, in the event of the formation of black spots, the laser pulse energy is increased and / or the spatial laser pulse spacing and / or the spatial laser pulse path spacing is reduced in order to provide the second laser parameters for the subsequent treatment. [5] Method according to one of claims 2 to 4, wherein the formation of the opaque blister layer and / or the black dots in the treatment area is determined by a camera device (24). [6] Method according to one of the preceding claims, wherein the treatment quality criterion comprises a separation result, wherein if the separation result is deemed to be deficient, the laser pulse energy is increased and / or the spatial laser pulse spacing and / or the spatial laser pulse path spacing is reduced to provide the second laser parameters for the subsequent treatment. [7] Method according to one of the preceding claims, wherein the treatment quality criterion comprises a recovery outcome, wherein if the recovery outcome is assessed as deficient, the laser pulse energy is reduced and / or the spatial laser pulse spacing and / or the spatial laser pulse path spacing is increased to provide the second laser parameters for the subsequent treatment. [8] Method according to one of the preceding claims, wherein the laser pulse energy is adjusted to a predetermined value of 5 nJ and / or the spatial laser pulse spacing is adjusted to a predetermined value of 0.1 µm and / or the spatial laser pulse path spacing is adjusted to a predetermined value of 0.2 µm. [9] Method according to one of the preceding claims, wherein predetermined limits are specified for the respective laser parameter which are not exceeded by adjusting the laser parameters, in particular 60 nJ as the lower limit and 300 nJ as the upper limit for the laser pulse energy and 1.5 µm as the lower limit and 18 µm as the upper limit for the spatial laser pulse spacing and 0.5 µm as the lower limit and 10 µm as the upper limit for the spatial laser pulse path spacing. [10] Method according to one of the preceding claims, wherein the laser parameters are adjusted depending on a treatment site where an impairment of the treatment quality has been detected. [11] Method according to one of the preceding claims, wherein the treatment quality is checked for a predetermined number of treatments with the first laser parameters before the second laser parameters are provided. [12] Control device (18) configured to carry out a respective procedure according to one of the preceding claims. [13] Treatment device (10) comprising at least one ophthalmic laser (12) for separating a corneal volume (14) with predefined interfaces of a human or animal eye by means of optical breakthrough, in particular by means of photodisruption and / or photoablation and at least one control device (18) according to claim 12. [14] Computer program comprising commands that cause the treatment device (10) according to claim 13 to perform a method according to any one of claims 1 to 11. [15] Computer-readable medium on which a computer program according to claim 14 is stored.

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