METHOD FOR CONTROLLING AN EYE SURGICAL LASER AND TREATMENT APPARATUS

Abstract

The invention relates to a method for controlling an eye surgical laser (12) of a treatment apparatus (10) for the separation of a volume body (14) with a predefined posterior interface (24) and a predefined anterior interface (26) from a human or animal cornea (16). The method includes controlling the laser (12) by means of a control device (18) of the treatment apparatus (10) such that it emits pulsed laser pulses in a shot sequence in a predefined pattern into the cornea (16), wherein the interfaces of the volume body (14) to be separated are defined by the predefined pattern and the interfaces are generated by means of an interaction of the individual laser pulses with the cornea (16) by the generation of a plurality of cavitation bubbles, wherein an arc length of the anterior interface (26) in radial direction and an arc length of the posterior interface (24) in radial direction are generated of equal length in all radial directions by means of at least one indentation (28) in one of the interfaces.

Claims

1. A method for controlling an eye surgical laser of a treatment apparatus for the separation of a volume body with a predefined posterior interface and a predefined anterior interface from a human or animal cornea, comprising: controlling the laser by means of a control device of the treatment apparatus such that it emits pulsed laser pulses in a shot sequence in a predefined pattern into the cornea, wherein the interfaces of the volume body to be separated are defined by the predefined pattern and the interfaces are generated by means of an interaction of the individual laser pulses with the cornea by the generation of a plurality of cavitation bubbles, and wherein an arc length of the anterior interface in radial direction and an arc length of the posterior interface in radial direction are generated of equal length in all radial directions by means of at least one indentation in one of the interfaces.

2. The method according to claim 1, wherein the at least one indentation is generated at a radially viewed outer part of the volume body, in particular in radially circumferential manner.

3. The method according to claim 1, wherein the volume body comprises an optical zone and a transition zone, wherein the at least one indentation is arranged in the transition zone.

4. The method according to claim 1, wherein if the separation of the volume body is performed for myopia correction, the at least one indentation is generated in the posterior interface.

5. The method according to claim 1, wherein if the separation of the volume body is performed for hyperopia correction, the at least one indentation is generated in the anterior interface.

6. The method according to claim 1, wherein if the separation of the volume body is performed for asymmetric correction, in particular astigmatism correction, the respective indentation is generated optionally in the anterior or posterior interface for a respective meridian of the volume body depending on the asymmetric correction.

7. The method according to claim 1, wherein the indentation is provided with a direction of curvature opposite to the curvature of the anterior and/or posterior interface, in particular in posterior direction.

8. A control device, which is formed to perform a method according to claim 1.

9. A treatment apparatus with at least one eye surgical laser for the separation of a volume body of a human or animal eye, in particular of a tissue lenticule, by means of photodisruption and/or photoablation, and at least one control device according to claim 8.

10. The treatment apparatus according to claim 9, wherein the laser is formed 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 of greater than 10 kHz, preferably between 100 kHz and 100 MHz.

11. The treatment apparatus according to claim 9, wherein the control device comprises at least one storage device for at least temporary storage of at least one control dataset, wherein the control dataset or datasets include(s) control data for positioning and/or focusing individual laser pulses in the cornea; and 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.

12. A computer program including commands, which cause the a treatment apparatus with at least one eye surgical laser for the separation of a volume body of a human or animal eye, in particular of a tissue lenticule, by means of photodisruption and/or photoablation, and at least one control device to execute a method according to claim 1.

13. A computer-readable medium, on which the computer program according to claim 12 is stored.

14. A method for performing a surgical procedure on a human or animal cornea for the separation of a volume body with a predefined posterior interface and a predefined anterior interface, wherein for separating the volume body by an eye surgical laser of a treatment apparatus the interfaces are generated by means of an interaction of the individual laser pulses with the cornea by the generation of a plurality of cavitation bubbles, and wherein an arc length of the anterior interface in radial direction and an arc length of the posterior interface in radial direction are generated of equal length in all radial directions by means of at least one indentation in one of the interfaces.

15. The method for performing a surgical procedure according to claim 14, wherein the at least one indentation is generated at a radially viewed outer part of the volume body, in particular in radially circumferential manner.

16. The method for performing a surgical procedure according to claim 14, wherein the volume body comprises an optical zone and a transition zone, wherein the at least one indentation is arranged in the transition zone.

17. The method for performing a surgical procedure according to claim 14, wherein if the separation of the volume body is performed for myopia correction, the at least one indentation is generated in the posterior interface.

18. The method for performing a surgical procedure according to claim 14, wherein if the separation of the volume body is performed for hyperopia correction, the at least one indentation is generated in the anterior interface.

19. The method for performing a surgical procedure according to claim 14, wherein if the separation of the volume body is performed for asymmetric correction, in particular astigmatism correction, the respective indentation is generated optionally in the anterior or posterior interface for a respective meridian of the volume body depending on the asymmetric correction.

20. The method for performing a surgical procedure according to claim 14, wherein the indentation is provided with a direction of curvature opposite to the curvature of the anterior and/or posterior interface, in particular in posterior direction.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0022] Further features of the invention are apparent from the claims, the figures and the description of figures. The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of figures and/or shown in the figures alone are usable not only in the respectively specified combination, but also in other combinations without departing from the scope of the invention. Thus, implementations are also to be considered as encompassed and disclosed by the invention, which are not explicitly shown in the figures and explained, but arise from and can be generated by separated feature combinations from the explained implementations. Implementations and feature combinations are also to be considered as disclosed, which thus do not comprise all of the features of an originally formulated independent claim. Moreover, implementations and feature combinations are to be considered as disclosed, in particular by the implementations set out above, which extend beyond or deviate from the feature combinations set out in the relations of the claims.

[0023] FIG. 1 is a schematic representation of a treatment apparatus according to the invention according to an exemplary embodiment.

[0024] FIG. 2 is a schematic representation of a cornea with an anterior and posterior interface in myopia correction.

[0025] FIG. 3 is a schematic representation of a cornea with an anterior and posterior interface in myopia correction as well as with an indentation according to an exemplary embodiment.

[0026] FIG. 4 is a schematic representation of a cornea with an anterior and posterior interface in hyperopia correction.

[0027] FIG. 5 is a schematic representation of a cornea with an anterior and posterior interface in hyperopia correction as well as an indentation according to an exemplary embodiment.

[0028] In the figures, identical or functionally identical elements are provided with the same reference characters.

DETAILED DESCRIPTION

[0029] FIG. 1 shows a schematic representation of a treatment apparatus 10 with an eye surgical laser 12 for the removal of a volume body 14 from a human or animal cornea 16 by means of photodisruption and/or photoablation. For example, the volume body 14 can be separated from a cornea 16 of an eye by the eye surgical laser 12 for correcting a visual disorder. A predefined pattern for removing the volume body 14 can be provided by a control device 18, in particular in the form of control data, such that the laser 12 emits pulsed laser pulses in a pattern predefined by the control data into the cornea 16 of the eye to form an anterior interface and a posterior interface, which together result in the volume body 14. Alternatively, the control device 18 can be a control device 18 external with respect to the treatment apparatus 10.

[0030] Furthermore, FIG. 1 shows that 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 for example a rotation scanner, to separate the volume body 14. The beam deflection device 22 can also be controlled by the control device 18 to remove the volume body 14.

[0031] Preferably, the illustrated laser 12 can be a photodisruptive and/or photoablative laser, which is formed to emit laser pulses in a wavelength range between 300 nanometers and 1400 nanometers, preferably between 700 nanometers and 1200 nanometers, at a respective pulse duration between 1 femtosecond and 1 nanosecond, preferably between 10 femtoseconds and 10 picoseconds, and a repetition frequency of greater than 10 kilohertz, preferably between 100 kilohertz and 100 megahertz. Optionally, the control device 18 additionally comprises a storage device (not illustrated) for at least temporary storage of at least one control dataset, wherein the control dataset or datasets include(s) control data for positioning and/or for focusing individual laser pulses in the cornea.

[0032] In FIG. 2, a cornea 16 with a volume body 14 is illustrated, as it is usually generated in myopia correction. Here, a schematic lateral cross-section through the cornea 16 is in particular illustrated, wherein the posterior interface 24 is formed flatter than the anterior interface 26. This results in the fact that an arc length of the posterior interface 24 is shorter than an arc length of the anterior interface 26, which can result in stresses and superposition problems in the cornea 16.

[0033] In order to avoid these stresses, myopia correction is illustrated in FIG. 3 as it can be performed according to a preferred embodiment for controlling the eye surgical laser 12 of the treatment apparatus 10. In particular, at least one indentation 28 is provided, by which the arc lengths of the two interfaces are generated of equal length, in particular of equal length in all radial directions. Preferably, the indentation 28 can be arranged at a radially viewed outer part of the volume body 14 and extend radially around the volume body 14. Particularly preferably, the indentation 28 can be arranged in a transition zone of the volume body 14 such that an optical zone, which can be provided for correction with optical effect, is not influenced by the indentation 28. In case of myopia correction, it is preferably provided that the indentation 28 is generated in the shorter posterior interface 24 such that the arc lengths compensate for each other. In order that the indentation 28 elongates the posterior interface 24, it can preferably be provided that it is formed with an opposite direction of curvature to the posterior interface 24, thus the indentation 28 is concave to the convexly oriented posterior interface 24. Thus, it can be achieved that stresses in the cornea 16 can be reduced or avoided in myopia correction.

[0034] In FIG. 4, an exemplary representation of hyperopia correction is shown, in which the anterior interface 28 is formed flatter than the posterior interface 24. Hereby, it follows that the arc length of the posterior interface 24 is shorter than the arc length of the anterior interface 26, whereby stresses can arise in the cornea 16.

[0035] In FIG. 5, hyperopia correction is illustrated, as it can be performed according to a preferred embodiment for controlling the eye surgical laser 12 of the treatment apparatus 10 to compensate for the previously mentioned length difference of the arc lengths of the anterior interface 26 and the posterior interface 24. Herein, the indentation 28 can be generated in the anterior interface 26, whereby the shorter one of the two arc lengths is extended such that the arc lengths of both interfaces are equally long. Herein too, the indentation 28 can preferably be again generated in the transition zone of the volume body 14.

[0036] Thus, a transition zone can overall be provided, which compensates for a discrepancy, which is generated in an optical zone of the volume body 14, in that a new division of the tissue superposition is provided, which generates arc lengths with equal length. Hereby, better coincidences between the interfaces can be generated, which can result in shorter recovery times of the cornea 16.