DE102020114791A1 - Method for controlling an ophthalmic surgical laser and treatment device - Google Patents

Abstract

The present invention relates to a method for controlling an ophthalmic laser (18) for the separation of a solid (12) with a posterior interface (14) and an anterior interface (16) from a human or animal cornea (32), comprising at least the following Steps: determining measurement data of eye-specific parameters and ametropia data of the eye to be treated; Defining the geometry of a reference solid (1) on the basis of the determined measurement and ametropia data for correcting corresponding ametropia of the eye, the reference solid (1) having an anterior and posterior reference interface (3, 2); Define the solid (12) to be separated under the conditions that (a) the distances in the same x / y spatial positions in the z direction, i.e. parallel to or on a visual axis (40) of the eye, between the posterior and the anterior Reference interface (2, 3) of the reference solid (1) and the posterior and the anterior interfaces (14, 16) of the solid (12) are essentially the same, and (b) at least the anterior interface (16) is not runs parallel to a surface (26) of the cornea (32); and controlling the laser (18) by means of a control device (20) in such a way that it emits pulsed laser pulses into the cornea (32) to generate the interfaces (14, 16) of the solid (12) to be separated, the interfaces (14, 16) can be generated by means of an interaction of the individual laser pulses with the cornea (32) by means of photodisruption. The invention also relates to a treatment device (10) with at least one eye surgery laser (18).

Description

The present invention relates to a method for controlling an ophthalmic laser for the separation of a solid with a predefined posterior boundary surface and a predefined anterior boundary surface from a human or animal cornea. The invention further relates to a treatment device with at least one ophthalmic laser for the separation of a corneal volume with predefined interfaces of a human or animal eye by means of photodisruption and at least one control device for the laser or lasers as well as a computer program and a computer-readable medium.

Devices and methods for controlling a photoablative ophthalmic laser are known. So describes the EP 1 628 606 B1 a method and a device for the precise processing of an organic tissue by means of a laser, wherein a pulsed laser and a beam focusing device are designed so that the laser beam pulses cause a photodisruption in a focus located within the organic material. A disadvantage of these known methods and devices, however, is that in the known photodisruptive methods and devices the laser is controlled in such a way that - viewed in the direction of the interior of the eye along the visual axis of the eye - there is always a concave posterior boundary surface further spaced from the corneal surface and a convex anterior boundary surface of the solid to be separated is created, which is closer to the corneal surface. Due to this standardized lenticular shape, however, the possibilities for positioning the volume body within the cornea, in particular within the stroma, are clearly limited. The anterior interface is always aligned parallel to the corneal surface or a corresponding contact surface of the corneal surface. By means of the individualized concave design of the posterior boundary surface and by removing the volume body, a correction of ametropia of the eye, such as hyperopia or myopia, is to be achieved.

By limiting the positional possibilities of the volume body within the cornea, disadvantageously, cases can also arise in which a required minimum distance between the anterior interface and the corneal surface or the posterior interface with deeper areas of the cornea can no longer be achieved. In these cases, known methods cannot be used. From the EP 2 211 804 B1 a treatment device for surgical correction of myopia or hyperopia on the eye is known. A control device controls a laser in such a way that a lenticular volume to be separated from the cornea has a minimum thickness at the edge of the volume of 5 to 50 µm in the case of a myopia correction and a minimum thickness in the area of the visual axis of also 5 in the case of a hyperopia correction to 50 µm. However, such specifications also limit the positional possibilities of the lenticular volume within the cornea and thus also the possible uses of this device.

It is therefore the object of the present invention to provide a method and a treatment device for controlling an ophthalmic laser for the separation of a solid with predefined interfaces from a human or animal cornea, with which the stated disadvantages of the prior art are overcome.

A generic method according to the features of claim 1, a generic treatment device with the features of claim 10 and a computer program according to the features of claim 13 and a computer-readable medium according to the features of claim 14 serve to solve this problem.

Advantageous refinements with expedient refinements of the invention are specified in the respective subclaims, with advantageous refinements of the method being regarded as advantageous refinements of the treatment device, the computer program and the computer-readable medium and vice versa.

A first aspect of the invention relates to a method for controlling an ophthalmic laser for the separation of a solid with a predefined posterior interface and a predefined anterior interface from a human or animal cornea, comprising determining measurement data of eye-specific parameters and ametropia data of the eye to be treated; defining the geometry of a reference solid on the basis of the determined measurement and ametropia data for correcting corresponding ametropia of the eye, the reference solid having an anterior and posterior reference interface; a definition of the geometry of the solid to be separated under the conditions that (a) the distances in the same x / y spatial positions in the z direction, i.e. parallel to or on a visual axis of the eye, between the posterior and the anterior reference interface the reference solid and the posterior and anterior interfaces of the solid are substantially the same, and (b) at least the anterior interface is non-parallel to a surface of the cornea; as well as controlling the laser by means of a control device in such a way that it emits pulsed laser pulses into the cornea to generate the interfaces of the solid to be separated, the interfaces being generated by means of an interaction of the individual laser pulses with the cornea by means of photodisruption. The method according to the invention makes use of the inventive knowledge that not only the posterior boundary surface of the volume body to be separated for the correction of ametropia of the eye, but both boundary surfaces, namely the posterior and anterior boundary surface, are designed accordingly. The laser is controlled in such a way that at least the anterior interface no longer runs parallel to the corneal surface or a corresponding contact surface of the corneal surface. As a result, there is also the possibility that a biconvex, biconcave, plano-convex or plano-concave volume body is formed within the cornea, in particular within the stroma, through the corresponding control of the laser beam by means of the control device. The formation of known volume bodies with convex-concave volume bodies can advantageously be dispensed with. The terms "plano-convex" and "plano-concave" are understood to mean that both the anterior and the posterior interface can each be designed to be planar. The corresponding, “non-planar” interface is then formed in a correspondingly convex or concave manner.

The control of the laser or the laser beam according to the invention also ensures that the resulting solid bodies have an improved overlapping of the edge regions of the anterior and posterior interfaces. The inventive design of the solid to be separated or removed by means of the inventive control of the laser or laser beam also makes it possible to place it relatively far within the cornea, in particular within the stroma, so that the distance between the anterior interface and the corneal surface can be significantly increased. This advantageously contributes to increased stability of the cornea after removal of the solid. Furthermore, the use of the same z-spacings used in conventional ametropia calculations ensures that the boundary surfaces of the volume body generated by the method according to the invention enclose the same volume as the conventional volume body generated by means of known methods. The optical correction of ametropia takes place via the design of the volume body to be removed through both interfaces.

According to the invention, there is also the possibility that the distances at the same x / y spatial positions in the z direction between the posterior and the anterior interface of the reference solid and the posterior and the anterior interface of the solid are the same and / or a maximum deviation of 5 % to each other. It has been found that even with the above-mentioned deviation in the distances, a volume body to be separated is created which can reliably perform the desired correction of the ametropia.

Furthermore, the control device can control the laser beam in such a way that the volume body to be separated is formed within the stroma of the cornea and / or a center of the volume body lies on a visual axis of a human or animal eye. This ensures that the solid can be aligned exactly within the cornea.

In further advantageous embodiments of the method according to the invention, the laser is controlled in such a way that at least one cut or at least one opening is produced in the cornea at a predefined angle and with a predefined geometry, the cut or opening intersecting an interface of the solid and up to a surface of the cornea is formed so that the volume body can be removed from the cornea via the cut or the opening. The volume body can be designed in the manner of a lenticle, as a result of which a simple removal via the mentioned cut or the mentioned opening is possible. Because the volume body to be separated is only described and defined by the boundary surfaces and these are also generated by means of photodisruption, there is no need to remove the volume body over the entire surface or over the entire volume. Only the interfaces are generated by means of photodisruption, so that the predefined volume can then be removed from the cornea. The cut or said opening can, however, also be produced mechanically, for example by means of a surgical knife.

In further advantageous refinements of the method according to the invention, the laser or the laser beam is controlled in such a way that the predefined pattern is at least partially ablated in a circular and / or spiral shape. This means that the laser beam is guided along or over the predefined pattern at least partially in a circular and / or spiral shape. The photodisruption can be started by the individual laser pulses in the center of the respective interface or also at the edge of the respective interface. In this way, the laser beam can be controlled in such a way that the individual laser pulses in the posterior interface move from the inside to the outside leading spiral and the individual laser pulses in the anterior interface, starting from the transition zone, are guided in a spiral leading from the outside to the inside. Such an incision or guidance of the laser beam can be carried out quickly and precisely.

In further advantageous refinements of the method according to the invention, the predefined pattern is defined on the basis of one or more control data records, the control data record or records including control data for positioning and / or for focusing individual laser pulses in the cornea. The determination of the control data records is known and results in particular from the topographical and / or pachymetric measurement of the cornea to be treated and the type of ametropia to be corrected. In particular, the control data records are generated at least by providing topographical and / or pachymetric and / or morphological data of the untreated cornea and providing topographical and / or pachymetric and / or morphological data of the volume to be removed within the cornea. The volume body to be separated is designed in such a way that the removal of the volume body also results in a refractive correction of the eye. The aforementioned ametropia of the eye can be myopia, hyperopia, presbyopia, astigmatism or other ametropia of the eye. Furthermore, there is the possibility that the pathologically changed area within the cornea is a cloudiness and / or a scar.

In further advantageous embodiments of the method according to the invention, the control device is designed in such a way that the laser generates laser pulses in a wavelength range between 300 nm and 1400 nm, preferably between 700 nm and 1200 nm, with a respective pulse duration between 1 fs and 1 ns, preferably between 10 fs and 10 ps, and a repetition frequency greater than 10 KHz, preferably between 100 KHz and 100 MHz. Such lasers are already used for photo-disruptive procedures in eye surgery. For example, the EP 2 211 803 B1 a corresponding femtosecond laser, which is used to produce a so-called lenticle, i.e. a lens-like volume body, within the cornea. The lenticle produced in this way is then removed from the cornea via an incision. The use of photo-disruptive 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. In laser technology, this area is subsumed under the term “deep ultraviolet”. This advantageously prevents these very short-wave and high-energy rays from causing unintentional damage to the cornea. Photodisruptive lasers of the type used here usually introduce pulsed laser radiation with a pulse duration between 1 fs and 1 ns into the corneal tissue. As a result, the power density of the respective laser pulse required for the optical breakthrough can be spatially narrowly limited, so that a high cutting accuracy is guaranteed when generating the interfaces. In particular, the range between 700 nm and 780 nm can also be selected as the wavelength range.

In further advantageous refinements of the method according to the invention, the surface of the cornea is a natural surface of the eye or a surface of the eye artificially created by removing or moving an uppermost corneal layer and / or by producing a corneal flap. The method according to the invention can thus be used for a large number of phototherapeutic methods.

A second aspect of the present invention relates to a treatment device with at least one eye surgical laser for the separation of a predefined corneal volume with predefined interfaces of a human or animal eye by means of photodisruption and at least one control device for the laser or lasers, which is designed to carry out the steps of the method according to the perform first aspect of the invention. The treatment device according to the invention enables the disadvantages that occur when using conventional ablative treatment devices to be reliably avoided.

The laser is suitable for laser pulses in a wavelength range between 300 nm and 1400 nm, preferably between 700 nm and 1200 nm, with a respective pulse duration between 1 fs and 1 ns, preferably between 10 fs and 10 ps, and a repetition frequency greater than 10 kHz , preferably between 100 KHz and 100 MHz. In particular, the range between 700 nm and 780 nm can be selected as the wavelength range.

In further advantageous refinements of the treatment device according to the invention, the control device comprises at least one computer unit for defining and calculating the geometries of the reference volume body and the volume body to be separated, at least one storage device for at least temporary storage of at least one control data record, with the control data record (s) control data for positioning and / or for focusing individual laser pulses in the cornea / cornea; and at least one beam device for beam guidance and / or beam shaping and / or Has beam deflection and / or beam focusing of a laser beam of the laser. The control data records mentioned are usually generated on the basis of a measured topography and / or pachymetry and / or morphology of the cornea to be treated and the type of ametropia to be corrected.

Further features and their advantages can be found in the descriptions of the first aspect of the invention, with advantageous configurations of each aspect of the invention being regarded as advantageous configurations of the respective other aspect of the invention.

A third aspect of the invention relates to a computer program comprising commands which cause the treatment device according to the second aspect of the invention to carry out the method steps according to the first aspect of the invention. A fourth aspect of the invention relates to a computer-readable medium on which the computer program according to the third aspect of the invention is stored. Further features and their advantages can be found in the descriptions of the first and second aspect of the invention, with advantageous configurations of each aspect of the invention being regarded as advantageous configurations of the respective other aspect of the invention.

• 1 eine Prinzipdarstellung zur Definition der Geometrie eines Referenz-Volumenkörpers zur Korrektur einer Myopie gemäß einem Verfahrensschritt des erfindungsgemäßen Verfahrens;
• 2 eine Prinzipdarstellung zur Definition eines abzutrennenden Volumenkörpers zur Korrektur einer Myopie gemäß einem weiteren Verfahrensschritt dem erfindungsgemäßen Verfahren;
• 3 eine Prinzipdarstellung zur Definition der Geometrie eines Referenz-Volumenkörpers zur Korrektur einer Hyperopie gemäß einem Verfahrensschritt des erfindungsgemäßen Verfahrens;
• 4 eine Prinzipdarstellung zur Definition eines abzutrennenden Volumenkörpers zur Korrektur einer Hyperopie gemäß einem weiteren Verfahrensschritt dem erfindungsgemäßen Verfahren; und
• 5 eine schematische Darstellung einer erfindungsgemäßen Behandlungsvorrichtung.

Further features of the invention emerge from the claims, the figures and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respectively specified combination, but also in other combinations, without falling within the scope of the invention leaving. There are thus also embodiments of the invention to be regarded as encompassed and disclosed, which are not explicitly shown and explained in the figures, but emerge and can be generated from the explained embodiments by means of separate combinations of features. Designs and combinations of features are also to be regarded as disclosed, which therefore do not have all the features of an originally formulated independent claim. In addition, designs and combinations of features, in particular through the statements set out above, are to be regarded as disclosed which go beyond the combinations of features set forth in the back-references of the claims or differ from them. The figures are schematic representations that may not be reproduced true to scale. It shows

• 1 a schematic diagram for defining the geometry of a reference volume body for correcting a myopia according to a method step of the method according to the invention;
• 2 a schematic diagram for the definition of a solid to be separated for the correction of a myopia according to a further method step of the method according to the invention;
• 3 a schematic diagram for defining the geometry of a reference solid for correcting a hyperopia according to a method step of the method according to the invention;
• 4th a schematic diagram for the definition of a volume body to be separated for the correction of a hyperopia according to a further method step of the method according to the invention; and
• 5 a schematic representation of a treatment device according to the invention.

1 shows a schematic diagram for defining the geometry of a reference solid 1 for correcting a myopia of a human or animal eye according to a method step of the present method. After measurement data of eye-specific parameters and ametropia data of the eye to be treated have been determined, a geometry of a reference solid is established 1 Defined on the basis of the determined measurement and ametropia data for the correction of corresponding ametropia of the eye. The reference solid 1 has an anterior and posterior reference interface 3 , 2 on. It can be seen that the individual laser pulses are used to generate a posterior reference interface 2 and the anterior reference interface 3 that together make up the reference solid 1 form, are controlled in such a way that a conventional, concavo-convex reference solid 1 results. It can also be seen that the anterior reference interface 3 roughly parallel to a corneal surface 5 or a corresponding contact surface of the corneal surface 5 is aligned. It is also clear that this alignment of the anterior reference interface 3 moving the reference solid 1 along a visual axis 7th of the eye is only possible to a limited extent, since the usual corneal thicknesses are in the area of the visual axis 7th between 500 and 700 µm there is always a minimum distance between the posterior reference interface 2 and the corresponding posterior border of the cornea 4th must be adhered to. It can also be seen that the anterior reference interface is located 3 and the posterior reference interface 2 in their edge areas in one area 8th overlap. However, this overlap is relatively incomplete because of the anterior reference interface 3 protrudes about 100 µm further into the interior of the eye than the corresponding end area of the posterior reference interface 2 . It is clear that this poor overlap leads to undesirable complications when the reference solid is removed 1 about the cut 6th can lead. To now these disadvantages of the reference solid 1 To be able to overcome, is in a next process step - starting from the already defined reference solid 1 - a geometry of one to be detached, ie from the cornea 4th , 32 solid to be removed 12th defined or calculated.

2 shows a basic diagram for the definition of the volume to be separated 12th for correcting a myopia according to a further method step of the present method. In conjunction with the 5 one first recognizes that for the creation of the solid to be separated 12th a laser beam 24 is controlled such that a posterior interface 14th and an anterior interface 16 with their edge areas 34 a lenticular, biconvex solid 12th form. The solid 12th can use the cut or the opening 36 from the cornea 32 can be removed. The cut 36 is designed in such a way that it extends from the corneal surface 26th up to a surface of the solid 12th suffices. Out 2 it becomes clear that the solid 12th due to its biconvex configuration in a relatively large area within the cornea 32 along a visual axis 40 is movable. This ensures that there is a minimum distance between the anterior interface 16 to the corneal surface 26th or a contact surface of the corneal surface 26th as well as a corresponding minimum distance of the posterior interface 14th to an internal, posterior interface of the cornea 32 is guaranteed. In contrast to the anterior reference interface 3 of the reference solid 1 (compare 1 ) is the anterior interface 16 of the solid 12th no longer parallel to the course of the corneal surface 26th or a corresponding contact surface of the corneal surface 26th aligned. The surface 26th the cornea 32 can be the natural surface of the eye or a surface of the eye artificially created by removing or moving an uppermost corneal layer and / or by producing a corneal flap. You can also see that there is a center 38 of the solid 12th on the visual axis 40 of the human or animal eye. This is a correct alignment of the solid 12th within the cornea 32 possible. It can also be seen that due to the good overlap of the two interfaces 14th , 16 in the edge areas 34 a stable or compact solid 12th arises, which is easily made over the cut 36 from the cornea 32 can be removed.

It also becomes clear that the volume of the solid 12th , namely that that through the interfaces 14th , 16 comprised volume of the solid 12th equal to or substantially equal to the volume of the reference solid 1 according to the 1 is. The geometry of the solid 12th is therefore defined in such a way that, on the one hand, the distances are at the same x / y spatial positions in the z direction, that is, parallel to or on a visual axis 40 of the eye, between the posterior and anterior reference interfaces 2 , 3 of the reference solid 1 and the posterior and anterior interfaces 14th , 16 of the solid 12th are essentially the same, and at least the anterior interface 16 non-parallel to the surface 26th the cornea 32 runs

So there is a possibility that the laser beam 24 is controlled in such a way that the distance in the z-direction, that is, parallel to or on the visual axis 40 of the eye, between the posterior and anterior interfaces 14th , 16 in the case of laser pulses lying at the same x / y positions, laser pulses corresponding to the spacing in the z-direction to form the reference solid 1 is equivalent to.

In addition, according to the schematic diagram 2 , especially in comparison to the schematic diagram according to 1 , it can be clearly seen that the slope of the anterior interface 16 versus the slope of the anterior reference interface 3 could be reduced significantly. This allows the stroke of the laser beam to be carried out when generating the solid 12th can also be significantly reduced, which in turn leads to faster production of the solid 12th leads.

3 shows a schematic diagram for defining the geometry of a reference solid 1 for correcting a hyperopia according to a method step of the present method. It can again be seen that the anterior reference interface 3 parallel to the corneal surface 5 or a contact surface of the corneal surface 5 is aligned. Because of this configuration of the anterior reference interface 3 it is only possible to a limited extent to use the reference solid 1 along the visual axis 7th of the eye to move, as both a minimum distance to the anterior reference interface 3 to the corneal surface 5 and a corresponding minimum distance from the posterior reference interface 2 to the posterior interface of the cornea in the eye 4th must be adhered to. To now these disadvantages of the reference solid 1 To be able to overcome, is in a next process step - starting from the already defined reference solid 1 - a geometry of one to be detached, ie from the cornea 4th , 32 solid to be removed 12th defined or calculated.

This shows 4th a schematic representation of the definition of the geometry or the creation of a solid to be separated 12th for correcting the hyperopia according to a further method step of the present method. It can be seen that the generated solid 12th over a relatively wide area of the cornea 32 along the visual axis 40 of the eye can be positioned. The solid produced according to this exemplary embodiment 12th has a biconcave shape due to the concave design of the posterior interface 14th and the corresponding concave design of the anterior interface 16 is formed. The marginal areas 34 of the interfaces 14th , 16 are connected via appropriate laser photodisruptions, so that the produced solid 12th again about the cut 36 from the cornea 32 can be removed. The center 38 of the solid 12th again lies on the visual axis 40 of the eye. It can be seen that the anterior interface 16 no longer parallel to the corneal surface 26th or to a corresponding contact surface of the corneal surface 26th is aligned. It also becomes clear that in comparison to the reference solid 1 (compare 3 ) a very clear distance between the anterior interface 16 and the corneal surface 26th results. This is beneficial as this increases the healing process after removal of the solid 12th clearly improved. In addition, is the minimum distance between the posterior interface 14th and a corresponding posterior interface of the cornea 32 guaranteed.

In addition, it becomes clear again that this is due to the interfaces 14th , 16 comprised volume of the solid 12th equal to or substantially equal to the volume of the reference solid 1 according to the 3 is. The laser beam 24 is in turn controlled in such a way that the distance in the z-direction, i.e. parallel to or on the visual axis 40 of the eye, between the posterior and anterior interfaces 14th , 16 in the case of laser pulses lying at the same x / y positions, laser pulses corresponding to the spacing in the z-direction to form the reference solid 1 (compare 3 ) is equivalent to.

5 shows a schematic representation of a treatment device 10 with an ophthalmic laser 18th for the separation of a predefined corneal volume or solid 12th each with the predefined posterior and anterior interfaces 14th , 16 from the cornea 32 of a human or animal eye by means of photodisruption. You can see that next to the laser 18th a control device 20th for the laser 18th is designed so that it emits pulsed laser pulses in a predefined pattern into the cornea, the interfaces 14th , 16 of the solid to be separated 12th can be generated by the predefined pattern using photodisruption. The interfaces 14th , 16 form the lenticle-like volume body in the illustrated embodiment 12th according to 2 off, with the design and position of the solid 12th is chosen such that it is after the removal of the solid 12th from the cornea 32 a desired refractive change to eliminate the diagnosed ametropia comes about. Furthermore it is off 5 that can be seen by the laser 18th generated laser beam 24 by means of a jet device 22nd , namely a beam deflection device, such as a scanner, towards the surface 26th the cornea 32 is distracted. In the illustrated embodiment, the surface 26th by placing the eye on a contact plate of a so-called patient interface (not shown) that is transparent, ie translucent, at least in central areas. The eye is coupled to the laser with the aid of the patient interface 18th or the treatment device 10 . The beam deflector 22nd is also controlled by the control device 20th controlled by said predefined pattern in the cornea 32 to create. Furthermore you can see again that the transition zone 34 is formed, which are the interfaces 14th , 16 connects with each other.

With the laser shown 18th it is a photodisruptive laser that is designed to generate laser pulses in a wavelength range between 300 nm and 1400 nm, preferably between 700 nm and 1200 nm, with a respective pulse duration between 1 fs and 1 ns, preferably between 10 fs and 10 ps, and a repetition frequency greater than 10 KHz, preferably between 100 KHz and 100 MHz. In particular, the range between 700 nm and 780 nm can be selected as the wavelength range.

The control device 20th also has a computer unit (not shown) for defining and calculating the geometries of the reference solid 1 and the solid to be separated 12th and a memory device (not shown) for at least temporary storage of at least one control data set, the control data set or sets of control data for positioning and / or for focusing individual laser pulses in the cornea 32 include. The position data and / or focusing data of the individual laser pulses are based on a previously measured topography and / or pachymetry and / or the morphology of the cornea 32 and the desired refractive correction.

Using the pulsed laser beam 24 passing through the beam deflector 22nd towards the Cornea 32 or towards the surface 26th the cornea 32 is steered, the interfaces 14th , 16 generated. The posterior and anterior interfaces 14th , 16 thereby overall form the lenticle-like volume body 12th out. Furthermore, in the exemplary embodiment shown, the laser generates 18th the further cut 36 that forms the solid at a predefined angle and with a predefined geometry 12th cuts and down to the surface 26th the cornea is formed. The one through the interfaces 14th , 16 defined solids 12th can then over the cut 36 from the cornea 32 removed.

In the illustrated embodiment it can be seen that the interfaces 14th , 16 by means of an interaction of the individual laser pulses with the cornea 32 can be generated by means of photodisruption. Thereby the laser beam 24 controlled so that the interfaces 14th , 16 a biconvex solid 12th form. It also becomes clear that the interfaces 14th , 16 in their marginal areas 34 overlap well. In the embodiment shown, the solid is biconvex 12th designed such that after its removal from the cornea 32 a correction of the optical properties of the eye, namely a correction of an existing myopia, results.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 1628606 B1 [0002]
• EP 2211804 B1 [0003]
• EP 2211803 B1 [0014]

Claims (14)

A method for controlling an ophthalmic laser (18) for the separation of a solid (12) with a posterior interface (14) and an anterior interface (16) from a human or animal cornea (32), comprising at least the following steps: - Determination of measurement data of eye-specific parameters and ametropia data of the eye to be treated; - Defining the geometry of a reference volume body (1) on the basis of the determined measurement and ametropia data for correcting corresponding ametropia of the eye, the reference volume body (1) having an anterior and posterior reference interface (3, 2); - Defining the solid to be separated (12) under the conditions that a) the distances in the same x / y spatial positions in the z direction, i.e. parallel to or on a visual axis (40) of the eye, between the posterior and the anterior reference interface (2, 3) of the reference solid ( 1) and the posterior and anterior interfaces (14, 16) of the solid (12) are essentially the same, and b) at least the anterior interface (16) runs non-parallel to a surface (26) of the cornea (32); and - Controlling the laser (18) by means of a control device (20) in such a way that it emits pulsed laser pulses into the cornea (32) to generate the interfaces (14, 16) of the solid (12) to be separated, the interfaces (14, 16) can be generated by means of an interaction of the individual laser pulses with the cornea (32) by means of photodisruption. Procedure according to Claim 1 , characterized in that the boundary surfaces (14, 16) form a biconvex, biconcave, plano-convex or plano-concave volume body (12). Procedure according to Claim 1 or 2 , characterized in that the control device (20) controls a laser beam (24) in such a way that the volume body (12) is formed within the stroma of the cornea (32). Method according to one of the preceding claims, characterized in that the control device (20) controls the laser beam (24) in such a way that a center (38) of the solid (12) lies on a visual axis (40) of a human or animal eye. Method according to one of the preceding claims, characterized in that the distances at the same x / y spatial positions in the z direction between the posterior and the anterior boundary surface of the reference solid and the posterior and the anterior boundary surface (14, 16) of the solid ( 12) are the same and / or have a maximum deviation of 5% from one another. Method according to one of the preceding claims, characterized in that the laser beam (24) is controlled in such a way that it is guided along or over the predefined pattern at least partially in a circular and / or spiral shape. Method according to one of the preceding claims, characterized in that the predefined pattern is defined using one or more control data sets, the control data set or sets comprising control data for positioning and / or for focusing individual laser pulses in the cornea (32). Procedure according to Claim 7 , characterized in that the control data records are generated at least by providing topographical and / or pachymetric and / or morphological data of the untreated cornea (32). Method according to one of the preceding claims, characterized in that the control device (20) is designed such that the laser (18) laser pulses in a wavelength range between 300 nm and 1400 nm, preferably between 700 nm and 1200 nm, with a respective pulse duration between 1 fs and 1 ns, preferably between 10 fs and 10 ps, and a repetition frequency greater than 10 KHz, preferably between 100 KHz and 100 MHz. Treatment device (10) with at least one ophthalmic laser (18) for the separation of a corneal volume (12) with predefined interfaces (14, 16) of a human or animal eye by means of photodisruption and at least one control device (20) for the laser or lasers (18) that is designed to carry out the steps of the method according to one of the Claims 1 until 9 to execute. Treatment device according to Claim 10 , characterized in that the laser (18) is suitable for laser pulses in a wavelength range between 300 nm and 1400 nm, preferably between 700 nm and 1200 nm, with a respective pulse duration between 1 fs and 1 ns, preferably between 10 fs and 10 ps, and a repetition frequency greater than 10 KHz, preferably between 100 KHz and 100 MHz. Treatment device according to Claim 10 or 11th full - at least one computer unit for defining and calculating the geometries of the reference volume body and the volume body to be separated (12); - At least one storage device for the at least temporary storage of at least one control data set, the control data set or sets comprising control data for positioning and / or for focusing individual laser pulses in the cornea (32); and - at least one beam device (22) for beam guidance and / or beam shaping and / or beam deflection and / or beam focusing of a laser beam (24) of the laser (18). Computer program, comprising instructions which cause the treatment device (10) according to one of the Claims 10 until 12th the process steps according to one of the Claims 1 until 9 executes. Computer-readable medium on which the computer program is based Claim 13 is stored.

Images