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

Abstract

Method for providing control data for an ophthalmic surgical laser (18) of a treatment device (10), wherein the treatment device (10) is designed to treat a human or animal eye to correct a refractive error, the method comprising the following steps performed by a control device (20): - Determining at least one laser setting (P, P1) of the laser (18) for treating the eye, wherein the laser setting (P1) is assigned to a calibration time point (t1) under at least one calibration environmental condition, and the respective laser setting (P, P1) is chosen such that a predetermined optimal value for refractive error treatment is achieved when treating the eye under the at least one calibration environmental condition, wherein the calibration period (t1) is a period in which a calibration of the laser (18) is carried out. - Determine at least one treatment environmental condition that is present at a treatment time (t2) different from the calibration time (t1), where the treatment time (t2) is a time at which the treatment of the refractive error of the eye is to be carried out, - only if at least one treatment environment condition deviates from at least one calibration environment condition according to a predefined deviation criterion: Correcting at least one laser setting (P, P1) according to a previously known correction function (K), wherein the corrected laser setting (P, P2) is chosen such that the optimal value for refractive error treatment is achieved when the eye is treated under at least one treatment environment condition, and - Providing control data for controlling the ophthalmic surgical laser (18), which includes at least one corrected laser setting (P, P2), characterized in that - the treatment environmental condition and / or the calibration environmental condition specify an air pressure and / or a temperature, and the respective treatment environmental condition is estimated depending on a previously known environmental data set, and / or - a cornea (26) and / or lens of the eye is provided for treatment and the correction function (K) is selected depending on one of several different tissue types of the cornea (26) which is to be treated by means of the treatment device (10).

Description

[0001] The invention relates to a method for providing control data for an ophthalmic surgical laser of a treatment device. The invention also relates to a method for controlling a treatment device with a corresponding ophthalmic surgical laser. Furthermore, the invention relates to a control device for carrying out a respective method. The invention also relates to a treatment device with at least one ophthalmic surgical laser. Finally, the invention relates to a computer program with instructions for carrying out a corresponding method using the treatment device and to a computer-readable medium with a corresponding computer program.

[0002] Treatment devices and methods for controlling ophthalmic or ophthalmic lasers, which are used, for example, to treat or correct optical refractive errors in an eye, are known per se in the prior art. DE 10 2020 133 181 A1 is considered the closest prior art. For example, a pulsed laser and a beam focusing device can be designed such that laser beam points in a focus within the tissue of the eye cause an optical breakthrough, in particular a photodisruption, at a predetermined cutting surface. As a result, the tissue is cut or severed along the cutting surfaces. Such cutting surfaces can define a cutting contour for a solid body or lenticule. This can be removed from the tissue of the eye for the treatment of refractive errors.When treating the cornea, this procedure is known as lenticule extraction.

[0003] To achieve the desired correction value for visual acuity after treatment, it is important to define the incision contour, especially its geometry and position, as precisely as possible. When inserting the incision contour into the tissue, the selected laser settings used to operate the laser play a particularly important role. For example, the laser settings determine how much tissue volume is removed or vaporized during irradiation with a laser pulse. The laser settings can therefore determine the sharpness (or blurriness) of the incision contour or cut surfaces.

[0004] To ensure that the laser settings are correctly selected, the laser is calibrated or recalibrated to a predetermined calibration target. Calibration is typically performed globally or across all lasers of the same type, for example, once a year. Individual adjustment before each laser treatment is too time-consuming and expensive.

[0005] Another factor that can affect the definition of the incision contour is the condition of the tissue to be treated. For example, it depends on the amount of water stored in the tissue. This can depend, in particular, on environmental conditions. Such environmental conditions can include temperature or humidity, for example. The effects of environmental conditions on the success of laser treatment have been investigated in the prior art.

[0006] For example, Mosquera et al. investigated the effects of seasonal changes on the performance of excimer lasers in the treatment of PIT and PMMA (Samuel Arba Mosquera, Shwetabh Verma; Cross sectional analysis of Impact of seasonal changes on Excimer Laser Ablation performance on PET and PMMA. Invest. Ophthalmol. Vis. Sci. 2020;61(7):3591).

[0007] In the publication by Luger et al., the effect of seasonal changes on residual refraction after corneal laser refractive surgery was analyzed (Michiel Luger, Tobias Ewering, Samuel Arba-Mosquera; Analysis of seasonal changes in residual refraction 1-year after corneal laser refractive surgery. Journal of Optometry 2014; 3(7):p.138-146).

[0008] It is the object of the present invention to provide an optimized laser setting for an upcoming treatment in a cost-effective manner, taking environmental conditions into account.

[0009] The problem is solved by the subject matter of the independent patent claims. Advantageous developments of the invention are disclosed by the dependent patent claims, the description, and the figures.

[0010] The invention is based on the realization that while calibrating all lasers to a common performance level makes all laser systems essentially function the same, the actual performance during eye treatment can vary due to different environmental conditions. This can lead to different results in refractive error treatment. However, these environmental conditions, which impair laser performance (the laser's efficiency) during refractive error treatment, are generally periodic, systematic, and modelable. Therefore, the environmental conditions can be used to easily and inexpensively adjust laser settings individually, especially before each treatment.For example, using a dynamic target, the performance can be adjusted for the time of the actual treatment depending on environmental conditions, such as the season in which the calibration took place. This allows the desired performance and thus the desired treatment outcome to be achieved during the actual treatment, regardless of the calibration time.

[0011] To this end, according to one aspect, the invention proposes a method for providing control data for an ophthalmic laser of a treatment device. The treatment device is designed to treat a human or animal eye in order to treat, in particular correct, a visual defect. The method comprises the following steps performed by a control device: First, at least one laser setting, i.e. one or more laser settings, of the laser for treating the eye is determined. The respective laser setting, i.e. the at least one laser setting, specifies the performance or efficiency of the laser. A laser setting can, for example, be a power density of the laser. The respective laser setting is assigned to a calibration time point under at least one calibration environmental condition. The calibration period is a time period in which a calibration of the laser is carried out. This means that it is a calibrated laser setting that was determined during a calibration under one or more specific calibration environmental conditions. The respective laser setting is or is selected such that a predetermined optimal value for the refractive error treatment is achieved when treating the eye under the at least one calibration environmental condition.

[0012] Next, at least one treatment environmental condition, i.e., one or more treatment environmental conditions, is determined that exists at a treatment time point different from the calibration time point. The treatment time point is a time point at which the treatment of the refractive error of the eye is to be performed or is planned. In particular, the treatment time point is after the calibration time point.

[0013] Only if the at least one treatment environmental condition deviates from the at least one calibration environmental condition according to a predetermined deviation criterion is the respective laser setting corrected according to a previously known correction function. The corrected laser setting is selected such that, when the eye is treated at the time of treatment under the treatment environmental condition, the optimal value for the refractive error treatment is again achieved. This means that the at least one treatment environmental condition can be compared with an associated calibration environmental condition, taking the deviation criterion into account, in order to correct the laser setting.

[0014] Finally, control data for controlling the ophthalmic surgical laser, which includes at least the at least one corrected laser setting, are provided.

[0015] Furthermore, the treatment environmental condition and / or the calibration environmental condition specify an air pressure and / or a temperature. These are therefore particularly environmental conditions that can change the tissue structure or condition of the ocular tissue to be treated. For example, they can promote water retention or water depletion in the tissue, thus changing the volume of the tissue.

[0016] In this context, the respective treatment environmental condition is estimated depending on a previously known environmental data set. This estimation has the advantage that the treatment environmental condition does not need to be measured precisely. Rather, the respective environmental condition can be determined depending on other known data. This data can, for example, be localization data that includes a geographical position (position data) and / or a time period (time data). The environmental data set can thus, for example, include an assignment rule that assigns an environmental condition or a range of environmental conditions to specific localization data. In this way, the associated treatment environmental condition for a known treatment location and / or the time of treatment can be estimated or read off based on the environmental data set. The environmental data set can, for example, be presented as a table, in particular as a look-up table, or as a function.

[0017] Alternatively, or in addition to the last two points, a cornea and / or lens of the eye are provided for treatment. The treatment can thus correct the cornea or lens.

[0018] In this context, according to the invention, the correction function is selected depending on one of several different corneal tissue types to be treated by the treatment device. Thus, differences in tissue composition can be taken into account when adjusting the laser.

[0019] In this case, this can mean, for example, that a large number of correction functions are stored, each assigned to a tissue type. The tissue type can be determined and the appropriate correction function can then be selected, for example, to correct the laser setting. In this case, a tissue type refers in particular to a type of tissue or a tissue layer that differs in its structure or composition from another tissue type. Using the cornea as an example of the tissue to be treated, a distinction can be made between the corneal epithelium, the collagen fibrils, the basement membrane and the endothelium. The differentiation according to tissue type can of course be made in more or less detailed ways. The tissue type can be determined or measured using known imaging or tomographic techniques, for example optical coherence tomography.

[0020] By correcting or adjusting the laser settings for the actual treatment, the advantage is that better treatment results can be achieved. In particular, there are fewer deviations from the optimal value for refractive error treatment.

[0021] In this case, the laser setting refers to a setting value for a laser parameter, such as the laser power. The laser setting specifically determines the laser performance, i.e., the laser's efficiency, when treating the eye. In this case, the laser performance specifically refers to the quality or grade of the treatment, for example, when ablating and / or removing corneal tissue. The laser setting can therefore determine how much tissue volume is removed during laser irradiation or, for example, how much tissue residue remains after laser irradiation. Specific examples of laser settings are described in more detail later.

[0022] The (calibrated) laser setting for calibration can be determined, for example, in test experiments. For this purpose, test tissue, such as artificial or donated corneal tissue, can be irradiated with the laser. An alternative way to determine the laser setting for calibration can be through patient studies, for example. The calibrated laser setting(s) can serve as a target value or calibration target to which each laser is uniformly calibrated.

[0023] In this context, the optimal value refers to a value that represents the quality or grade of the refractive error treatment. The optimal value can thus indicate whether the refractive error treatment or correction was successful or not. The optimal value can, for example, be a measurement determined from refractive error data during an eye examination. For example, the optimal value can be measured in diopters or indicate the residual refraction of the eye after treatment.

[0024] The deviation criterion in this case describes a rule and / or algorithm whose application or implementation determines the deviation between the calibration environmental condition and the treatment environmental condition. To determine the deviation, the deviation criterion is specifically applied. In this case, the deviation criterion can, for example, specify a threshold value for a difference between the treatment environmental condition and the associated calibration environmental condition.

[0025] The control data used to control the laser can, in addition to at least one laser setting, include, for example, additional setting parameters for the laser. For example, the control data can specify a geometry and position for the cutting contour in the eye tissue to be treated. The control data can additionally include, for example, a respective data set for positioning and / or focusing individual laser pulses in the cornea. The data set of control data can, for example, include coordinates in three-dimensional space as irradiation points or irradiation areas for the eye laser. The irradiation points in their entirety can simulate the cutting contour. To separate tissue, the laser beam can, for example, be focused on the irradiation points in the volume of the eye.This means that the energy of the laser beam required for separation is delivered to a specific coordinate point in the desired plane within the volume of the eye. The coordinate points can describe coordinates in a suitable coordinate system (Cartesian, polar, cylindrical).

[0026] 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.

[0027] The invention includes embodiments which provide additional advantages.

[0028] According to one embodiment, the treatment environmental condition and / or the calibration environmental condition specify a humidity level. This is therefore also an environmental condition that can change the tissue structure or condition of the ocular tissue to be treated. For example, this can promote water retention or water depletion in the tissue, thus changing the volume of the tissue.

[0029] According to one embodiment, the respective treatment environmental condition is measured using a sensor device. This measurement has the advantage that the respective environmental condition is precisely known. The sensor device used can be, for example, a thermometer, a hygrometer, or a barometer, or a combination of these.

[0030] In connection with the environmental data set, one embodiment provides that the environmental data set specifies the respective treatment environmental condition as a function of localization data, wherein the localization data includes a geographical position and / or a geographical altitude and / or a season and / or a month. This provides the advantage that local and / or seasonal differences can be taken into account for correcting the laser setting. In particular, climatic changes in certain regions or due to seasonal influences can be taken into account for correcting the laser setting.

[0031] A geographical position can be understood, for example, as a geographical area or zone. An area can be, for example, a country, a continent, the division into the Southern or Northern Hemisphere, or another predefined geographical boundary. In this context, the geographical height refers to the so-called altitude, i.e., the relative height above mean sea level.

[0032] A season, for example, can also be understood as a season. Preferably, the season refers to one of the four well-known periods: spring, summer, autumn, and winter. These periods are distinguished by their prevailing climatic characteristics. Of course, another predefined period of the calendar year, such as a month, a week, a day, or a quarter, can also be used to utilize the location data.

[0033] In the environmental dataset, for example, a season and / or a geographical location can be assigned to a specific temperature range or average temperature. This can also be implemented analogously for the other location data and environmental conditions. To determine the treatment environmental condition, the treatment location and / or treatment time can be searched for in the respective environmental dataset, and the resulting treatment environmental condition can be read off.

[0034] According to one embodiment, the respective laser setting is an energy density, a power, a power density, a wavelength, a pulse duration, a frequency, a focal area, and / or a focal plane. Preferably, one or more of these laser settings can be used to adjust the performance of the laser.

[0035] According to one embodiment, the correction function specifies a profile of the respective laser setting as a function of at least one environmental condition or as a function of localization data assigned to the at least one environmental condition. This means that the correction function can be an assignment rule that assigns each laser setting to precisely one environmental condition or a set of localization data, such as those described above. In particular, the correction function specifies the laser setting with which the optimum value can be achieved for the respective environmental condition. The correction function thus shows the change in laser performance as a function of the respective environmental condition. Using the correction function, the correction for the laser setting can be easily read off. The correction function can be determined, for example, through test experiments or investigations.For example, as mentioned previously, an artificial or human test tissue can be irradiated under given environmental conditions.

[0036] In other words, the correction function can, for example, comprise a rule and / or algorithm whose application or execution determines the correction setting, i.e., the corrected laser setting. The correction function is thus performed to determine the correction setting.

[0037] The correction function can be in the form of a table, in particular a so-called look-up table and / or a table with interpolations, or in the form of a curve. The correction function can be an analytical function, such as a sine function or Fourier series (i.e., a sum of sine functions), or a combination of these.

[0038] A further aspect of the invention relates to a method for controlling a treatment device. The method comprises the method steps of at least one embodiment of a method as described above. Furthermore, the method for controlling the treatment device also comprises the step of transmitting the provided control data to at least one ophthalmic surgical laser of the treatment device.

[0039] The respective method may include at least one additional step that is executed precisely when a use case or application situation occurs that has not been explicitly described here. This step may, for example, include outputting an error message and / or a request for user feedback. Additionally or alternatively, it may be provided that a default setting and / or a predetermined initial state is set.

[0040] A further aspect of the invention relates to a control device which is designed to carry out the steps of at least one embodiment of one or both of the methods described above. For this purpose, the control device can have a computing unit for electronic data processing, such as a processor. The computing unit can comprise at least one microcontroller and / or at least one microprocessor. The computing unit can be embodied as an integrated circuit and / or microchip. Furthermore, the control device can comprise an (electronic) data memory or a memory unit. Program code which encodes the steps of the respective embodiment of the respective method can be stored on the data memory. The program code can comprise the control data for the respective laser.The program code can be executed by the computing unit, causing the control device to execute the respective embodiment. The control device can be embodied as a control chip or control unit. The control device can be comprised, for example, of a computer or computer network.

[0041] A further aspect of the invention relates to a treatment device comprising at least one ophthalmic or ophthalmic laser and a control device 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 volume with a predefined cutting contour from tissue of a human or animal eye by means of optical disruption, in particular to at least partially separate it by means of photodisruption and / or to ablate tissue layers by means of (photo)ablation and / or to cause a laser-induced refractive index change in the tissue, such as the cornea and / or the lens of the eye.

[0042] A further aspect of the invention relates to a computer program. The computer program comprises instructions that, for example, form a program code. The program code can comprise 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 previously described method or at least one embodiment thereof.

[0043] A further 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 designed, for example, as a data memory, in particular at least partially as a volatile or non-volatile data memory. A non-volatile data memory can be a flash memory and / or an SSD (solid state drive) and / or a hard disk. A volatile data memory can be a RAM (random access memory). The instructions can be present, for example, as source code of a programming language and / or as assembler and / or as binary code.

[0044] Further features and advantages of one of the described aspects of the invention may arise from the further development of another aspect of the invention. The features of the embodiments of the invention may thus be present in any combination with one another, unless explicitly described as mutually exclusive.

[0045] Additional features and advantages of the invention are described below with reference to the figure(s) in the form of advantageous exemplary embodiments. The features or combinations of features of the exemplary embodiments described below can be present in any combination with one another and / or with the features of the embodiments. This means that the features of the exemplary embodiments can supplement and / or replace the features of the embodiments, and vice versa. Thus, the invention also encompasses and discloses configurations that are not explicitly shown or explained in the figures, but which emerge and can be produced from the exemplary embodiments and / or embodiments through separate combinations of features.Thus, embodiments are also to be regarded as disclosed which do not have all the features of an originally formulated claim or which go beyond or deviate from the combinations of features set out in the references to the claims.

[0046] It shows: Fig. 1 a schematic representation of a treatment device according to an exemplary embodiment; Fig. 2 shows a schematic process flow diagram for a method for providing control data for an ophthalmic surgical laser of the treatment device according to an exemplary embodiment; and Fig. 3 a schematic representation of a correction function for correcting a laser setting of the ophthalmic surgical laser according to an exemplary embodiment.

[0047] In the figures, identical or functionally identical elements are provided with the same reference numerals.

[0048] The Fig. 1 shows a schematic representation of a treatment device 10 with an ophthalmic surgical laser 18. For the treatment of a visual impairment of an eye, the laser 18 in the present embodiment is designed to separate a lenticule (volume body) 12 defined by control data from a cornea (cornea 26), for example by means of photodisruption and / or ablation.

[0049] Fig. 1 shows the cornea 26 in a cross-section, i.e., a side view extending in a plane along the visual axis A of the eye. The cornea 26 is bounded in the direction of the visual axis A by an anterior corneal surface 30 and a posterior corneal surface 32. For separating the lenticule 12, a posterior or first boundary surface 14 and an anterior or second boundary surface 16 of the lenticule 12 are specified in the control data. These boundary surfaces 14, 16 can form a cutting contour for the lenticule 12. A cavitation bubble path for separating the lenticule 12 from the cornea 26 can be generated on the boundary surfaces 14, 16 using the laser 18.

[0050] In Fig. 1, a control device 20 for the laser is formed next to the laser 18. The control device 20 can be used to control the laser 18 and thus, for example, emit pulsed laser pulses, for example, in a predefined pattern to generate the interfaces 14, 16. Alternatively to the illustrated embodiment, the control device 20 can be a control device external to the treatment device 10.

[0051] According to the embodiment in Fig. 1, the treatment device 10 also comprises a beam steering device 22. The beam steering device 22 is designed, for example, as a rotary scanner. By means of the beam device 22, as shown in the Fig. 1, a laser beam 24 generated by the laser 18 can be deflected toward the cornea 26. The beam device 22 can also be controlled by the control device 20, specifically such that the laser beam 24 can be controlled to create the interfaces 14, 16.

[0052] The planning of the corrections to be achieved, thus the geometry and position of the lenticule 12 to be removed, can be carried out using standard methods. For example, a refractive error dataset containing refractive error data describing the refractive error can be determined from examination data resulting from eye examinations. Suitable examination methods include, for example, topography and / or pachymetry and / or tomography, by means of which the morphology of the cornea 26 or the optical refractive error correction to be produced can be determined. The refractive error data can, for example, specify a refractive power correction and / or a lenticule diameter. For example, the refractive error data can be specified in diopters.From the refractive error data, the geometry and position of the lenticule 12 can be determined using known calculation methods, from which the anterior and posterior boundary surfaces 15, 16 of the lenticule 12 are determined. The refractive error data can, for example, be received by the control device 20 from a data server or entered directly into the control device 20.

[0053] Position and geometry may be included in the form of position data and focusing data in control data for controlling the laser 18.

[0054] The control data can thus include information on positioning or focusing individual laser pulses in the cornea 26. The Fig. The control device 20 shown in Figure 1 optionally has a storage device (not shown) for at least temporarily storing at least one control data set with the control data for controlling the ophthalmic surgical laser 18.

[0055] The laser 18 shown may preferably be a photodisruptive and / or ablative laser which is designed to emit laser pulses in a length range between 300 nm and 1,400 nm, preferably between 700 nm and 1,200 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.

[0056] The control data can contain one or more laser settings that specify the laser's performance. These settings can include, for example, energy density, power, power density, wavelength, pulse duration, frequency, focal area, and / or focal plane.

[0057] To determine the appropriate laser settings for laser 18, the laser is calibrated or verified by the manufacturer before treatment, particularly before delivery. For calibration, a predetermined test tissue, such as PMMA (polymethyl methacrylate), can be irradiated with the laser beam 24 at a specific calibration time until the respective laser setting achieves a desired optimal value. The respective optimal value can be determined, for example, through test trials or by evaluating patient studies.

[0058] The optimum value is a value, in particular a standardized value, at which, for example, a certain volume of tissue can be removed or vaporized with the laser beam 24. This allows the sharpness of the incision contour in the tissue to be adjusted, preferably without removing too much tissue or leaving undesirable tissue residues. This ensures that the treatment achieves the desired result. Typically, these calibrated laser settings, determined during calibration, are then used to treat the refractive error, in this case, for example, lenticule extraction.

[0059] However, human tissue, including corneal tissue, is susceptible to environmental influences. For example, environmental conditions such as temperature, air pressure, and / or humidity can alter tissue composition, such as water content. This can lead to different laser performance and, consequently, refractive error treatment results when using calibrated laser settings under different environmental conditions.

[0060] Therefore, it may be advisable to adjust the laser 18 to the prevailing environmental conditions before a treatment, especially before each upcoming treatment. This involves correcting the calibrated laser settings depending on the environmental conditions prevailing at the time of treatment, which are also referred to below as treatment environmental conditions.

[0061] Fig. Figure 2 shows a corresponding method in a schematic process flow diagram. In the method, in a step S1, the laser setting determined at the calibration time and at least one calibration environmental condition is first determined. This determination may, for example, include reading the calibration values ​​from the memory device.

[0062] The method then continues in step S2. In step S2, at least one treatment environmental condition is determined that exists at the treatment time point different from the calibration time point. The treatment time point is the time or period at which the treatment of the refractive error is to be performed. The method then continues in step S3.

[0063] In step S3, a check is carried out to determine whether the at least one treatment environmental condition deviates from the at least one calibration environmental condition according to a predefined deviation criterion. This means that a comparison is made of how similar the environmental conditions are at the time of calibration and at the time of treatment. The deviation criterion can, for example, be a limit value for the maximum permissible difference. In particular, the agreement of the environmental conditions is checked.

[0064] If no deviation according to the deviation criterion is detected in step S3 (N), the method continues in step S4. In step S4, the original laser settings, i.e., the calibrated laser settings to which the laser was calibrated, can be retained. These laser settings can then be used to control the ophthalmic surgical laser 18, as previously described.

[0065] If, however, a deviation is detected according to the deviation criterion (Y), the method continues in a step S5. In step S5, the at least one laser setting is corrected according to a predetermined or previously known correction function K. The corrected laser setting is selected such that the optimal value for the refractive error treatment is achieved when treating the eye at the treatment time under the respective treatment environmental conditions. The method then continues in a step S6. In step S6, the at least one corrected laser setting is provided in the form of control data for controlling the laser 18.

[0066] In order to determine the environmental conditions at the time of treatment, a sensor device such as a thermometer, a hygrometer or a barometer can be used. The treatment environmental conditions can thus be measured. Additionally or alternatively, the treatment environmental conditions can be estimated depending on a previously known environmental data set. This means that the environmental conditions can be read as an estimated value based on other known data. Examples of such data are localization data that specify the treatment location and / or the treatment time. The localization data can therefore be, for example, a geographical position or a geographical area, a geographical altitude or a predetermined period of time or a time interval, for example based on a calendar year. The period of time can be, for example, a year of the year or season or a month or a week or a day.Such localization data are typically associated with specific climatic or environmental conditions, making it particularly easy to infer the respective environmental condition.

[0067] Fig. Figure 3 shows an example of how the localization data can be used to estimate the laser setting using the correction function K. Fig. 3 shows a schematic diagram of the correction function K, which is represented here by way of example as an analytical function or curve. Data describing the correction function K can, for example, be stored in the memory device.

[0068] The diagram in Fig. Figure 3 shows a two-dimensional xy diagram. The laser setting, in this example the power P, is plotted on the y-axis (ordinate). The localization data, in this example the time t, is plotted on the x-axis (abscissa). In this example, the x-axis is scaled by months from January to December, each with a one-month increment. Each month is assigned a specific environmental condition or group of environmental conditions. For example, an average temperature may be lower in April than in September.

[0069] By simulating the environmental condition(s) assigned to each month in laboratory tests, for example, the optimal value for the laser power P can be determined for each month. This results in the correction function K. In particular, a test fabric made of PMMA can be used in the test experiments, as previously mentioned. Fig. Figure 3 shows a test function F resulting from irradiation of the test tissue with the optimal values ​​over the period shown. Since it is known that the test tissue behaves inversely to actual corneal tissue during laser irradiation under certain environmental conditions, the correction function K can be modeled as a mirror function of the test function F.

[0070] Fig. Figure 3 shows the correction function K (and the test function F) with an example sinusoidal curve in the period from January to December. The laser power P exhibits a minimum value between March (Mar) and April (Apr), while the maximum value is between August (Aug) and September (Sep).

[0071] As in Fig. As shown in Figure 3, the diagram, i.e., the correction function K shown, is assigned to another localization data set, in this example, a geographical area. In the exemplary embodiment, the geographical area is a country, namely Germany (GER). This means that the laser power P, which can be derived from the correction function K, specifically refers to monthly climatic conditions prevailing in Germany (GER).

[0072] In Fig. 3 it is now clearly visible that at different times between calibration and treatment, different settings in the power P of the laser 18 are necessary in order to achieve the optimal correction. Fig.Figure 3 shows, as an example, a calibration time t1 in April / Apr. In comparison, the treatment time t2 is selected in September / Sep. A check according to the aforementioned deviation criterion may reveal that the time periods—in this case, April / Apr and September / Sep—do not match. A correction of the laser setting P is necessary.

[0073] Due to the sinusoidal curve of the correction function K shown, a calibrated laser setting in April (Apr) results, in this case a power P1, that is much lower than the power P2 required to correct the refractive error in September (Sept). To achieve the same success in refractive error treatment—for example, to treat the same number of diopters—a significantly higher power P2 is required for a treatment in September (Sept) than it was during the calibration in April (April). Therefore, for the treatment in September (Sept), the power P2 must be increased as the corrected laser setting.

[0074] Overall, the exemplary embodiments show that the performance of a treatment device 10 with laser 18 for correcting refractive errors can change depending on environmental conditions, such as climatic influences. However, these changes are generally periodic, systematic, and modelable. Furthermore, the changes can affect different tissue structures differently. The method described here considers seasons or time periods as a correction function, which implicitly takes into account different, dynamic calibration targets throughout the year. Thus, the dynamic calibration targets can maintain the performance when treating a patient in contrast to the test material. This allows for overall better results in correcting refractive errors and fewer scattering effects. Overall, the invention thus shows a seasonal laser for treating refractive errors.

Claims

[1] Method for providing control data for an ophthalmic surgical laser (18) of a treatment device (10), wherein the treatment device (10) is designed to treat a human or animal eye in order to treat a visual impairment, the method comprising the following steps carried out by a control device (20): - Determining at least one laser setting (P, P1) of the laser (18) for treating the eye, wherein the laser setting (P1) is assigned to a calibration time (t1) under at least one calibration environmental condition, and the respective laser setting (P, P1) is selected such that a predetermined optimum value for the refractive error treatment is achieved during treatment of the eye under the at least one calibration environmental condition, wherein the calibration period (t1) is a period in which a calibration of the laser (18) is carried out, - determining at least one treatment environmental condition that exists at a treatment time (t2) different from the calibration time (t1), wherein the treatment time (t2) is a time at which the treatment of the refractive error of the eye is to be carried out, - only if the at least one treatment environmental condition deviates from the at least one calibration environmental condition according to a predetermined deviation criterion: correcting the at least one laser setting (P, P1) according to a previously known correction function (K), wherein the corrected laser setting (P, P2) is selected such that the optimum value for the refractive error treatment is achieved when the eye is treated under the at least one treatment environmental condition, and - Providing control data for controlling the ophthalmic surgical laser (18), which comprises at least the at least one corrected laser setting (P, P2), characterized by , that - the treatment environmental condition and / or the calibration environmental condition specify an air pressure and / or a temperature, and the respective treatment environmental condition is estimated depending on a previously known environmental data set, and / or - a cornea (26) and / or lens of the eye is provided for treatment and the correction function (K) is selected depending on one of several different tissue types of the cornea (26) which is to be treated by means of the treatment device (10). [2] The method of claim 1, wherein the treatment environmental condition and / or the calibration environmental condition indicates a humidity. [3] Method according to one of the preceding claims, wherein the respective treatment environmental condition is measured by means of a sensor device. [4] The method of claim 3, wherein the environmental data set indicates the respective treatment environmental condition as a function of location data, the location data comprising a geographical position and / or a geographical altitude and / or a season and / or a month. [5] Method according to one of the preceding claims, wherein the respective laser setting (P) is an energy density, a power, a power density, a wavelength, a pulse duration, a frequency, a focal area and / or a focal plane. [6] Method according to one of the preceding claims, wherein the correction function (K) indicates a course of the respective laser setting (P) as a function of at least one environmental condition or as a function of localization data associated with the at least one environmental condition. [7] Method for controlling a treatment device (10), the method comprising the following steps: - the method steps of a method according to one of the preceding claims, and - transmitting the provided control data to a respective ophthalmic surgical laser (18) of the treatment device (10). [8] Control device (20) which is designed to carry out a respective method according to one of the preceding claims. [9] Treatment device (10) with at least one ophthalmic surgical laser (18) for the treatment of a human or animal eye for treating a visual impairment and at least one control device (20) according to claim 8, wherein the treatment device (10) is designed to produce at least one cutting surface for separating tissue layers in the eye by means of optical breakdown, in particular by means of photodisruption and / or photoablation. [10] Computer program comprising instructions causing the treatment device (10) according to claim 9 to carry out a method according to any one of claims 1 to 6 and / or a method according to claim 7. [11] A computer-readable medium on which a computer program according to claim 10 is stored.

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