OPHTHALMOLOGICAL DEVICE FOR SURGICAL TREATMENT OF A CORNEA

Abstract

An ophthalmological device for surgical treatment of a cornea comprises a laser source, a focusing optical module, a scanner system, and an electronic circuit configured to control the scanner system to move the focus of the pulsed laser beam generated by the laser source to cut inside the cornea a lenticule, an opening incision in an exterior surface of the cornea, and two access channels which connect the opening incision to the posterior lenticule surface and to the anterior lenticule surface to provide access for a surgical tool through the opening incision to the posterior lenticule surface and the anterior lenticule surface, respectively. The access channels are cut to overlap at least partially from a top view perspective onto the cornea.

Claims

1. An ophthalmological device for surgical treatment of a cornea of an eye, the ophthalmological device comprising: a laser source configured to generate a pulsed laser beam; a focusing optical module configured to make the pulsed laser beam converge onto a focus in the cornea; a scanner system configured to move the focus to target locations in the cornea; and an electronic circuit configured to control the scanner system to: move the focus to cut inside the cornea a lenticule, the lenticule having a posterior lenticule surface and an anterior lenticule surface, and move the focus to cut in the cornea at least one opening incision in an exterior surface of the cornea, a first access channel, and a second access channel, the first access channel connecting the at least one opening incision to the posterior lenticule surface to provide access for a surgical tool through the at least one opening incision to the posterior lenticule surface, and the second access channel connecting the at least one opening incision to the anterior lenticule surface to provide access for the surgical tool through the at least one opening incision to the anterior lenticule surface, wherein the first access channel and the second access channel overlap at least partially from a top view perspective onto the cornea.

2. The ophthalmological device of claim 1, wherein the electronic circuit is configured to control the scanner system to move the focus to cut one common opening incision in the exterior surface of the cornea for the first access channel and the second access channel, to provide access for the surgical tool through the common opening incision and the first access channel to the posterior lenticule surface, and through the common opening incision and the second access channel to the anterior lenticule surface.

3. The ophthalmological device of claim 2, wherein the electronic circuit is further configured to control the scanner system to move the focus to cut the first access channel and the second access channel with a partially common access channel to provide access for the surgical tool through the common opening incision, the common access channel and the first access channel to the posterior lenticule surface, and through the common opening incision, the common access channel and the second access channel to the anterior lenticule surface.

4. The ophthalmological device of claim 1, wherein the electronic circuit is configured to control the scanner system to move the focus to cut in the cornea a first opening incision in the exterior surface of the cornea for the first access channel to provide access for the surgical tool through the first opening incision and the first access channel to the posterior lenticule surface, and a separate second opening incision in the exterior surface of the cornea for the second access channel to provide access for the surgical tool through the second opening incision and the second access channel to the anterior lenticule surface.

5. The ophthalmological device of claim 1, wherein the electronic circuit is configured to control the scanner system to move the focus to cut the first access channel in the cornea with a first width, and to cut the second access channel in the cornea with a second width different from the first width.

6. The ophthalmological device of claim 1, wherein the electronic circuit is configured to control the scanner system to move the focus to cut the first access channel in the cornea with a first symmetry plane, and to cut the second access channel in the cornea with a second symmetry plane, whereby the first symmetry plane and the second symmetry plane run parallel to each other.

7. The ophthalmological device of claim 1, wherein the electronic circuit is configured to control the scanner system to move the focus to cut the first access channel in the cornea with a first symmetry plane, and to cut the second access channel in the cornea with a second symmetry plane, whereby the first symmetry plane and the second symmetry plane run at an angle to each other.

8. The ophthalmological device of claim 1, wherein the electronic circuit is configured to control the scanner system to move the focus to cut the first access channel and the second access channel with a trapezoid shaped outline from the top view perspective onto the cornea.

9. The ophthalmological device of claim 1, wherein the electronic circuit is configured to control the scanner system to move the focus to cut at least one of the first access channel or the second access channel in the cornea from with an increasing width from the opening incision in the exterior surface of the cornea towards the posterior lenticule surface or the anterior lenticule surface, respectively.

10. The ophthalmological device of claim 1, wherein the electronic circuit is configured to control the scanner system to move the focus to cut the first access channel along a first channel axis having at least one change of direction from the opening incision in the exterior surface of the cornea to the posterior lenticule surface, and to cut the second access channel along a second channel axis having at least one change of direction from the opening incision in the exterior surface of the cornea to the anterior lenticule surface.

11. The ophthalmological device of claim 1, wherein the electronic circuit is configured to control the scanner system to move the focus to cut the first access channel to approach tangentially the posterior lenticule surface, and to cut the second access channel to approach tangentially the anterior lenticule surface.

12. The ophthalmological device of claim 1, wherein the electronic circuit is configured to control the scanner system to move the focus to cut the first access channel with a first entry channel, from the at least one opening incision in the exterior surface of the cornea to a first turning area inside the cornea, and a first connecting channel from the first turning area to the posterior lenticule surface, and to cut the second access channel with a second entry channel from the at least one opening incision in the exterior surface of the cornea to a second turning area inside the cornea, and a second connecting channel from the second turning area to the anterior lenticule surface.

13. The ophthalmological device of claim 12, wherein the electronic circuit is configured to control the scanner system to move the focus to cut the first entry channel and the second entry channel with a common channel portion from the at least one opening incision in the exterior surface of the cornea to a forking area inside the cornea.

14. A computer program product comprising a non-transitory computer-readable medium having stored thereon computer program code for controlling a processor of an ophthalmological device which comprises a laser source configured to generate a pulsed laser beam, a focusing optical module configured to make the pulsed laser beam converge onto a focus in the cornea, and a scanner system configured to move the focus to target locations in the cornea, whereby the computer program code is configured to control the processor such that the processor: directs the scanner system to move the focus to cut inside the cornea a lenticule, the lenticule having a posterior lenticule surface and an anterior lenticule surface, and to move the focus according to cut in the cornea at least one opening incision, a first access channel, and a second access channel, the first access channel connecting the at least one opening incision to the posterior lenticule surface to provide access for a surgical tool through the at least one opening incision to the posterior lenticule surface, and the second access channel connecting the at least one opening incision to the anterior lenticule surface to provide access for the surgical tool through the at least one opening incision to the anterior lenticule surface, whereby the first access channel and the second access channel overlap at least partially from a top view perspective onto the cornea.

15. The computer program product of claim 14, wherein the computer program code further is configured to control the processor such that the processor directs the scanner system to move the focus to cut one common opening incision in the exterior surface of the cornea for the first access channel and the second access channel, to provide access for the surgical tool through the common opening incision and the first access channel to the posterior lenticule surface, and through the common opening incision and the second access channel to the anterior lenticule surface

16. The computer program product of claim 15, wherein the computer program code further is configured to control the processor such that the processor directs the scanner system to move the focus to cut the first access channel and the second access channel with a partially common access channel to provide access for the surgical tool through the common opening incision, the common access channel and the first access channel to the posterior lenticule surface, and through the common opening incision, the common access channel and the second access channel to the anterior lenticule surface.

17. The computer program product of claim 14, wherein the computer program code further is configured to control the processor such that the processor directs the scanner system to move the focus to cut in the cornea a first opening incision in the exterior surface of the cornea for the first access channel to provide access for the surgical tool through the first opening incision and the first access channel to the posterior lenticule surface, and a separate second opening incision in the exterior surface of the cornea for the second access channel to provide access for the surgical tool through the second opening incision and the second access channel to the anterior lenticule surface

18. The computer program product of claim 14, wherein the computer program code further is configured to control the processor such that the processor directs the scanner system to move the focus to cut the first access channel in the cornea with a first width, and to cut the second access channel in the cornea with a second width different from the first width.

19. The computer program product of claim 14, wherein the computer program code further is configured to control the processor such that the processor directs the scanner system to move the focus to cut the first access channel in the cornea with a first symmetry plane, and to cut the second access channel in the cornea with a second symmetry plane, whereby the first symmetry plane and the second symmetry plane run parallel to each other.

20. A method for surgical treatment of a cornea of an eye, the method comprising: generating, by a laser source, a pulsed laser beam; making, by a focusing optical module, the pulsed laser beam converge onto a focus in the cornea; moving, by a scanner system, the focus to target locations in the cornea; moving, by the scanner system the focus to cut inside the cornea a lenticule, the lenticule having a posterior lenticule surface and an anterior lenticule surface; and moving, by the scanner system, the focus to cut in the cornea at least one opening incision in an exterior surface of the cornea, a first access channel, and a second access channel, wherein the first access channel connecting the at least one opening incision to the posterior lenticule surface to provide access for a surgical tool through the at least one opening incision to the posterior lenticule surface, wherein the second access channel connecting the at least one opening incision to the anterior lenticule surface to provide access for the surgical tool through the at least one opening incision to the anterior lenticule surface, wherein the first access channel and the second access channel overlap at least partially from a top view perspective onto the cornea.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present disclosure will be explained in more detail, by way of example, with reference to the drawings in which:

[0031] FIG. 1 shows a block diagram that schematically illustrates an ophthalmological device for surgical treatment of a cornea with a pulsed laser beam, said device comprising a focusing optical module for focusing the pulsed laser beam in the cornea, and a scanner system for moving the focus to target locations in the cornea.

[0032] FIGS. 2-6 show schematic top views of a cornea with a lenticule cut in the cornea, and a first access channel and a second access channel cut in the cornea and providing access through one or more incisions in the cornea to the posterior lenticule surface and the anterior lenticule surface, respectively, whereby, from the top view perspective, the first access channel and the second access channel overlap at least partially.

[0033] FIGS. 7-9 show schematic cross-sectional views of a section of a cornea with a lenticule cut in the cornea, and a first access channel and a second access channel cut in the cornea and providing access through a common incision in the cornea to the posterior lenticule surface and the anterior lenticule surface, respectively, whereby, in direction from the anterior surface of the cornea to the posterior surface of the cornea, the first access channel and the second access channel overlap at least partially.

[0034] FIG. 10 shows a schematic cross-sectional view of a section of a cornea with a lenticule cut in the cornea, a first access channel and a second access channel cut in the cornea and providing access through separate incisions in the cornea to the posterior lenticule surface and the anterior lenticule surface, respectively, whereby, in direction from the anterior surface of the cornea to the posterior surface of the cornea, the first access channel and the second access channel overlap at least partially.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] In FIG. 1, reference numeral 1 relates to an ophthalmological device for surgical treatment of a cornea 20 of an eye 2 with a pulsed laser beam B.

[0036] As illustrated schematically in FIG. 1, the ophthalmological device 1 comprises a laser source 11 for generating a pulsed laser beam B, a focusing optical module 12 for focusing the pulsed laser beam B in the cornea 20 onto a focus F, and a scanner system 13 for moving the focus F to target locations in the cornea 20.

[0037] In particular, the laser source 11 comprises a femtosecond laser for producing femtosecond laser pulses, which have pulse widths of typically 10 fs to 1000 fs (1 fs=10.sup.−15 s). The laser source 11 is arranged in a separate housing or in a housing shared with the focusing optical module 12.

[0038] The focusing optical module 12 is configured to focus the pulsed laser beam B and/or the laser pulses in the cornea 20 onto a focus F, i.e. for making the pulsed laser beam B converge to a focal point or spot in the cornea 20. The focusing optical module 12 comprises one or more optical lenses. By way of example, the focusing optical module 12 is installed in an application head 14, which can be placed onto the eye 2. The application head 14 or the focusing optical module 12, respectively, is preferably placed onto the eye 2 by way of an at least partly light-transparent contact body 15 or a fluid chamber and it is fastened to the eye 2 by means of a vacuum-controlled suction ring 16, for example, with the contact body 15 and the suction ring being 16 connected to the application head 14 in a fixed or removable manner. In an embodiment, the focusing optical module 12 comprises a focus adjustment device for setting the focal depth, for example one or more movable lenses, in the focusing optical module 12 or upstream of the focusing optical module 12, or a drive for moving the entire focusing optical module 12.

[0039] The scanner system 13 is configured to move the focus F to target locations in the cornea 20 by guiding and directing the pulsed laser beam B and thus the focus F to target locations in the cornea 20. The scanner system 13 comprises one or more scanner modules configured to guide and direct the pulsed laser beam B and thus the focus F in a x/y-work-plane which is normal to a z-axis, whereby the z-axis is aligned with or essentially parallel to a projection axis p of the focusing optical module 12, as illustrated schematically in FIG. 1. Depending on the embodiment, the one or more scanner modules comprise one or more actuators configured to move the focusing optical module 12 such that the focus F is moved along a work line in the x/y-work-plane, and/or one or more deflection mirrors, each movable about one or two axes, configured to deflect the pulsed laser beam B and/or the laser pulses such that the focus F is moved along the work line in the x/y-work-plane. The scanner system 13 further comprises a z-modulator configured to move the focus F along the z-axis which is aligned with or essentially parallel to the projection axis p of the focusing optical module 12. For example, the z-modulator comprises a divergence modulator configured to dynamically change the divergence of the pulsed laser beam B. Various further and more specific embodiments of the scanner system 13 are described by the applicant in patent applications US 2019/0015250, US 2019/0015251, and US 2019/0015253 which are hereby incorporated by reference.

[0040] The ophthalmological device 1 further comprises an electronic circuit 10 for controlling the laser source 11 and the scanner system 13. The electronic circuit 10 implements a programmable control device and comprises e.g. one or more processors 100 with program and data memory and programmed software modules for controlling the processors 100, and/or other programmable circuits or logic units such as ASICs (application specific integrated circuits).

[0041] The electronic circuit 10 is configured to control the scanner system 13 to move the focus F to cut inside the cornea 20 a lenticule L which has a posterior lenticule surface Lp and an anterior lenticule surface La, as illustrated in FIGS. 7-10. For example, the electronic circuit 10 is configured to control the scanner system 13 to move the focus F to cut the lenticule L inside the cornea 20 as described by the applicant in patent applications US 2019/0015250, US 2019/0015251, and US 2019/0015253 which are hereby incorporated by reference.

[0042] The electronic circuit 10 is further configured to control the scanner system 13 to move the focus F to cut in the cornea 20 one or two opening incisions Co, Co1, Co2 in the exterior (anterior) surface A of the cornea 20, as illustrated in FIGS. 7-10. More specifically, the electronic circuit 10 is configured to control the scanner system 13 to move the focus F to cut in the exterior (anterior) surface A of the cornea 20 one common opening incision Co, as illustrated in FIGS. 7-9, or two separate opening incisions Co1, Co2, as illustrated in FIG. 10.

[0043] Furthermore, the electronic circuit 10 is configured to control the scanner system 13 to move the focus F to cut in the cornea 20 access channels Ch1, Ch2 which connect the one or two opening incisions Co, Co1, Co2 to the posterior lenticule surface Lp and to the anterior lenticule surface La, respectively. More specifically, a first one of the access channels Ch1 connects the common opening incision Co or one of the two separate opening incisions Co1 to the posterior lenticule surface Lp. Moreover, a second one of the access channels Ch2 connects the common opening incision Co or one of the two separate opening incisions Co2 to the anterior lenticule surface La. The first access channel Ch1 is cut to approach tangentially the posterior lenticule surface Lp. The second access channel Ch2 is cut to approach tangentially the anterior lenticule surface La. The first access channel Ch1 enables a surgeon to access the posterior lenticule surface Lp by inserting a surgical tool, particularly a dissector, through the common opening incision Co or through one of the separate opening incisions Co1, and through the first access channel Ch1, making it possible for the surgeon to loosen and separate the posterior lenticule surface Lp from the neighbouring cornea tissue. The second access channels Ch2 enables the surgeon to access the anterior lenticule surface La by inserting the surgical tool, particularly the dissector, through the common opening incision Co or through one of the separate opening incisions Co2, and through the second access channel Ch2, making it possible for the surgeon to loosen and separate the anterior lenticule surface La from the neighbouring cornea tissue. In FIGS. 2-4, reference numeral (letter) k indicates the length of the access channel Ch1 from the opening incision Co to the posterior lenticule surface Lp. In FIGS. 2-4, reference numeral (letter) 1 indicates the length of the access channel Ch2 from the opening incision Co to the anterior lenticule surface La.

[0044] The electronic circuit 10 is configured to control the scanner system 13 to move the focus F to cut the access channels Ch1, Ch2 in the cornea 20 in such a fashion that the access channels Ch1, Ch2 overlap at least partially when viewed from a top view perspective onto the cornea 20, i.e. in a viewing direction along the z-axis, as illustrated in FIGS. 2-10.

[0045] In FIGS. 2-10, reference numeral (letter) E refers to a vertical plane which runs through the z-axis or the projection axis p, respectively. In FIGS. 7-10, the vertical plane E is assumed to coincide with the drawing plane.

[0046] As depicted in FIGS. 7-10, the access channels Ch1, Ch2 are each composed of two or more cut surfaces. The access channel Ch1 leading to the posterior lenticule surface Lp comprises a first cut surface which forms an entry channel q, extending from the opening incision Co, Co1 to a turning area Q with a change of direction (of the channel axis of access channel Ch1), and a second cut surface which forms a connecting channel, extending from the turning area Q to the posterior lenticule surface Lp. The access channel Ch2 leading to the anterior lenticule surface La comprises a first cut surface which forms an entry channel r, extending from the opening incision Co, Co2 to a turning area R with a change of direction R (of the channel axis of access channel Ch2), and one or more cut surfaces extending from the area with the change of direction R to the anterior lenticule surface La. As can be seen in FIGS. 2-10, the access channels Ch1, Ch2 and their cut surfaces run essentially normal to the vertical plane E.

[0047] The electronic circuit 10 is further configured to control the scanner system 13 to move the focus F to cut the access channels Ch1, Ch2 in the cornea 20 in such a fashion that the access channels Ch1, Ch2 are produced with different geometric characteristics which enable a tactile distinction and differentiation of the access channels Ch1, Ch2 by the surgeon. For example, the access channels Ch1, Ch2 are produced with different channel widths d, e, i.e. with different widths d, e of their cut surfaces, as illustrated in FIGS. 2-4, and/or with different angular arrangements with regards to the vertical plane E, as illustrated in FIGS. 4-5, and/or with different location or placement, as illustrated in FIGS. 3-4. These different widths d, e, angular arrangements, and/or locations of the access channels Ch1, Ch2 can be detected in a tactile fashion by the surgeon inserting alternatingly a surgical tool, particularly a dissector, into the access channels Ch1, Ch2.

[0048] In the following paragraphs, different embodiments and/or configurations of the access channels Ch1, Ch2 are described with reference to FIGS. 2-6, showing top views of the access channels Ch1, Ch2, and to FIGS. 7-10, showing cross-sectional views of the access channels Ch1, Ch2. For the sake of clarity, it is pointed out here that any of the embodiments and/or configurations of the access channels Ch1, Ch2 illustrated in top view in FIGS. 2-6 can be combined with any of the embodiments and/or configurations of the access channels Ch1, Ch2 illustrated in cross-sectional in FIGS. 7-10. It is further particularly pointed out that, any of the embodiments and/or configurations of the access channels Ch1, Ch2 illustrated in top view in FIGS. 2-6 can be produced with one common opening incision Co, as illustrated in FIGS. 7-9, or, although not illustrated in FIGS. 2-6, with two separate opening incisions Co1, Co2, as illustrated in FIG. 10. Finally, it is pointed out that the electronic circuit 10 is configured to control the scanner system 13 to move the focus F to cut the access channels Ch1, Ch2 in the cornea 20 to produce one or more of these embodiments and/or configurations and combinations thereof, for example, as selected or selectable by an operator.

[0049] In the embodiment illustrated in FIG. 2, the access channels Ch1 and Ch2 have a common symmetry plane E=E1=E2 which coincides with the vertical plane E. As further illustrated, the access channels have Ch1, Ch2 a different channel width d and e, respectively, making possible for the surgeon a tactile distinction of the two access channels Ch1, Ch2. The channel width d, e is defined by the widths of the cut surfaces forming the access channels have Ch1, Ch2. As can be seen in FIGS. 2-4, the channel width d, e is defined by the extension of the cut surfaces forming the access channels Ch1, Ch2 with respect to the symmetry plane E1, E2 of the respective access channel Ch1, Ch2.

[0050] In the embodiment illustrated in FIG. 3, the access channels Ch1 and Ch2 have each their own separate symmetry plane E1, E2 which run parallel to the vertical plane E and thus parallel to each other. As in the embodiment of FIG. 2, the access channels Ch1, Ch2 have a different channel width d, e and are further distinguishable in a tactile fashion for the surgeon by their location, as they have separate symmetry planes E1, E2 and are thus offset or shifted with respect to each other.

[0051] [51] In the embodiment illustrated in FIG. 4, the access channels Ch1 and Ch2 have each their own separate symmetry plane E1, E2 which run at an angle a to each other (from the top view perspective). As in the embodiments of FIGS. 2 and 3, the access channels Ch1, Ch2 have a different channel width d, e and are further distinguishable in a tactile fashion for the surgeon by their angular arrangement with respect to each other.

[0052] In the embodiment illustrated in FIG. 5, the access channels Ch1 and Ch2 have each their own separate central plane C1, C2 which run parallel to the z-axis or the projection axis p, respectively, with a different angle θ or μ, respectively, to the vertical plane E and thus forming and enclosing an angle θ+μ between each other (from the top view perspective). Unlike in the embodiments of FIGS. 2 and 3, the access channels Ch1, Ch2 have the same channel width d, but are distinguishable in a tactile fashion for the surgeon by their angular arrangement with respect to each other.

[0053] In the embodiment illustrated in FIG. 6, the access channels Ch1 and Ch2 have a trapezoid shape, from the top view perspective. The access channels Ch1 and Ch2 are arranged at an angle to each other (from the top view perspective) and are thus distinguishable in a tactile fashion for the surgeon by their angular arrangement with respect to each other.

[0054] FIGS. 7-10 show in schematic cross-sectional view, where the drawing plane is assumed to coincide with the vertical plane E, different arrangements of the cut surfaces forming the access channels Ch1, Ch2.

[0055] In the embodiment illustrated in FIG. 7, the access channels Ch1 and Ch2 share a common entry channel r, extending from the common opening incision Co to the turning area R. The common entry channel r is produced by a first cut surface which is cut from the common opening incision Co into the cornea tissue at an entry angle φ with respect to the anterior surface A of the cornea 20. At the turning area R, the access channel Ch2 changes direction to a connection channel with length 1, from the turning area R to the anterior lenticule surface La, formed by second cut surface. For the access channel Ch1 to the posterior lenticule surface Lp, the entry channel r continues as entry channel q from the turning area R to the turning area Q, formed by the continued first cut surface. At the turning area Q, the access channel Ch1 changes direction to a connection channel with length k, from the turning area Q to the posterior lenticule surface Lp, formed by third cut surface.

[0056] In the embodiment illustrated in FIG. 8, the access channels Ch1 and Ch2 have separate entry channels r and q, extending from the common opening incision Co to the turning area R or the turning area Q, respectively. The entry channel q for access channel Ch1 is produced by a first cut surface which is cut from the common opening incision Co into the cornea tissue at an entry angle φ with respect to the anterior surface A of the cornea 20. At the turning area Q, the access channel Ch1 changes direction to a connection channel with length k, from the turning area Q to the posterior lenticule surface Lp, formed by a second cut surface. The entry channel r for the access channel Ch2 to the anterior lenticule surface La is produced by a third cut surface which is cut from the common opening incision Co into the cornea tissue at an entry angle with respect to the entry channel q for the access channel Ch1. At the turning area R, the access channel Ch2 changes direction to a connection channel with length 1, from the turning area R to the anterior lenticule surface La, formed by a fourth cut surface.

[0057] In the embodiment illustrated in FIG. 9, the access channels Ch1 and Ch2 share a common entry channel r, extending with length s from the common opening incision Co to the turning area R. The common entry channel r is produced by a first cut surface which is cut from the common opening incision Co into the cornea tissue at an entry angle φ with respect to the anterior surface A of the cornea 20. At the turning area R, the access channel Ch2 changes direction to a two-part connection channel formed by a second and a third cut surface, from the turning area R to the anterior lenticule surface La. For the access channel Ch1 to the posterior lenticule surface Lp, the entry channel r continues as entry channel q from the turning area R to the turning area Q, formed by the continued first cut surface. At the turning area Q, the access channel Ch1 changes direction to a connection channel with length k, from the turning area Q to the posterior lenticule surface Lp, formed by a fourth cut surface.

[0058] In the embodiment illustrated in FIG. 10, the access channels Ch1 and Ch2 have separate entry channels r and q, extending from separate opening incisions Co1 or Co2, respectively, to the turning area R or the turning area Q, respectively. The entry channel q for access channel Ch1 is produced by a first cut surface which is cut from the opening incision Co1 into the cornea tissue at an entry angle φ with respect to the anterior surface A of the cornea 20. At the turning area Q, the access channel Ch1 changes direction to a connection channel with length k, from the turning area Q to the posterior lenticule surface Lp, formed by second cut surface. The entry channel r for the access channel Ch2 to the anterior lenticule surface La is produced by a third cut surface which is cut from the opening incision Co2 into the cornea tissue at an entry angle ω with respect to the anterior surface A of the cornea 20. At the turning area R, the access channel Ch2 changes direction to a connection channel with length 1, from the turning area R to the anterior lenticule surface La, formed by a fourth cut surface.