Method for generating control data for eye surgery, and eye-surgical treatment device and method

A computer implemented method of generating control data for an eye-surgery treatment apparatus that, by application of a laser device, separates tissue layers in a cornea of an eye, wherein, during operation of the laser device, a contact glass having a contact surface is pressed against the cornea and deforms the cornea to conform to a shape of the contact surface, the method comprising:

• generating the control data for the laser device such that the control data specifies target point coordinates for the laser device that are located in the cornea and,
• taking into account, in the generation of the target-point coordinates, the deformation of the cornea, caused by the contact glass, that exists during the operation of the laser device,
• wherein the taking into account the deformation of the cornea comprises execution of the following to determine a displacement of a point P in the non-deformed cornea, the displacement being caused by deformation:
• determining, on a reference surface of the non-deformed cornea, in relation to the point P, a point O that is located such that a surface normal running through the point O goes through the point P, the reference surface being either the anterior surface of the cornea or a surface obtained through radial contraction of the anterior surface by a bend line displacement L,
• determining a distance SO between a vertex S of the reference surface and the point O, the distance SO being the arc length on the reference surface,
• determining on a contact-glass reference surface a point O′ that is located at the distance SO from a contact-surface vertex, the contact-glass reference surface being either the contact surface of the contact glass or a surface obtained through radial contraction of the contact surface by the bend line displacement L and/or by a thickness F′ of a fluid film on the cornea,
• determining, on a surface normal through the point O′, a point P′ that has the same distance from O′ as the point P has from the point O, and
• using the point P′ as a point P displaced by the deformation;
• and/or wherein the taking into account the deformation of the cornea comprises execution of the following to determine a displacement of a point Q′ in the deformed cornea, the displacement being caused by relaxation:
• determining on the contact-glass reference surface, in relation to the point Q′, a point O′ that is located such that a surface normal running through the point O′ goes through the point Q′,
• determining a distance SO′ between the vertex S and the point O′, the distance SO′ being the arc length on the contact-glass reference surface,
• determining, on the reference surface, a point O that is located at the distance SO′ from the vertex S,
• determining, on a surface normal through the point O, a point Q that has the same distance from O as the point Q′ has from the point O′, and
• using the point Q as a point Q′ displaced by the relaxation.

A computer implemented method of generating control data for an eye-surgery treatment apparatus that, by application of a laser device, separates tissue layers in a cornea of an eye, wherein, during operation of the laser device, a contact glass having a contact surface is pressed against the cornea and deforms the cornea to conform to the shape of the contact surface, the method comprising:

• generating the control data for the laser device such that the control data specifies target point coordinates for the laser device that are located in the cornea and,
• taking into account, in the generation of the target-point coordinates, the deformation of the cornea, caused by the contact glass, that exists during the operation of the laser device,
• wherein the taking into account the deformation of the cornea comprises using the following transformation, between a spherical coordinate system (φ, α, R), related to the non-deformed cornea, and a spherical coordinate system (φ′, α′, R′) for the cornea placed against the contact glass and deformed thereby:
• ϕ
• =
• ϕ
• ′
• α
• ′
• ·
• R
• ′
• =
• R
• ·
• (
• α
• +
• c
• 5
• 40
• 
• α
• 5
• -
• c
• 7
• 84
• 
• α
• 7
• +
• K
• 1
• )
• R
• ′
• =
• R
• KGL
• +
• R
• -
• R
• cv
• 
• (
• 1
• +
• f
• 4
• 8
• 
• α
• 4
• -
• f
• 6
• 12
• 
• α
• 6
• +
• K
• 2
• )
• wherein RKGL is a radius of the contact surface, RCV is a radius of the non-deformed anterior surface of the cornea, c5, c7, f4 and f6 are experimentally established correction factors that can be equated approximately to 1, K1 is a first optional correction term for higher odd orders of α, and K2 is a second an optional correction term for higher odd orders of α.

A computer implemented method of generating control data for an eye-surgery treatment apparatus that, by application of a laser device, separates tissue layers in the cornea of the eye, wherein, during operation of the laser device, a contact glass having a contact surface is pressed against the cornea and deforms the cornea to conform to the shape of the contact surface, the method comprising:

• generating the control data for the laser device such that the control data specifies target point coordinates for the laser device that are located in the cornea;
• and,
• taking into account, in the generation of the target-point coordinates, the deformation of the cornea, caused by the contact glass, that exists during operation of the laser device;
• wherein the taking into account the deformation of the cornea comprises using the following transformation, between a spherical coordinate system (φ, α, R), related to the non-deformed cornea, and a spherical coordinate system (φ′, α′, R′) for the cornea that is placed against the contact glass and deformed:
• φ=φ′
• α′(RKGL−F′−L)=α(RCV−L)
• R′=R+RKGL−RCV
• wherein RKGL is a radius of the contact surface, RCV is a radius of the non-deformed anterior surface of the cornea, F′ is a thickness of a fluid film between the cornea and the contact surface pressed against it, and L is a displacement of a bend line of the cornea of the eye from the surface of the cornea into the interior of the cornea, the displacement having been determined experimentally, F′ or L being equated approximately to zero.

A method of eye-surgery treatment that, by application of a laser device, separates tissue layers in the cornea of an eye, comprising:

• pressing a contact glass having a contact surface against the cornea, such that the contact glass deforms the cornea to conform to a shape of the contact surface;
• generating control data for the laser device such that the control data specifies target point coordinates for the laser device that are located in the cornea and,
• taking into account, in the generation of the target-point coordinates, the deformation of the cornea, caused by the contact glass, that exists during the operation of the laser device;
• wherein the taking into account the deformation of the cornea comprises execution of the following to determine a displacement of a point P in the non-deformed cornea, the displacement being caused by deformation:
• determining on a reference surface of the non-deformed cornea, in relation to the point P, a point O that is located such that the surface normal running through the point O goes through the point P, the reference surface being either the anterior surface or a surface obtained through radial contraction of the anterior surface by a bend line displacement L,
• determining a distance SO between a vertex S of the reference surface and the point O is determined, the distance SO being the arc length on the reference surface,
• determining on a contact-glass reference surface a point O′ that is located at the distance SO from the contact-surface vertex, the contact-glass reference surface being either the contact surface or a surface obtained through radial contraction of the contact surface by the bend line displacement L and/or by a thickness F′ of a fluid film on the cornea,
• determining, on a surface normal through the point O′ a point P′ that has the same distance from O′ as the point P has from the point O, and
• using the point P′ as a point P displaced by the deformation;
• and/or wherein the taking into account the deformation of the cornea comprises execution of the following to determine a displacement of a point Q′ in the deformed cornea, the displacement being caused by relaxation:
• determining, on the contact-glass reference surface, in relation to the point Q′, a point O′ that is located such that the surface normal running through the point O′ goes through the point Q′,
• determining a distance SO′ between the vertex S and the point O′, the distance SO′ being the arc length on the contact-glass reference surface,
• determining on the reference surface a point O that is located at the distance SO′ from the vertex S,
• determining on a surface normal in the point O a point Q that has the same distance from O as the point Q′ has from the point O′, and
• using the point Q as a point Q′ displaced by the relaxation.

A method of eye-surgery treatment that, by application of a laser device, separates tissue layers in the cornea of the eye, comprising:

• pressing a contact glass having a contact surface against the cornea, such that the contact glass deforms the cornea to conform to the shape of the contact surface;
• generating control data for the laser device such that the control data specifies target point coordinates for the laser device that are located in the cornea and,
• taking into account, in the generation of the target-point coordinates, the deformation of the cornea, caused by the contact glass, that exists during the operation of the laser device;
• wherein the taking into account the deformation of the cornea comprises using the following transformation, between a spherical coordinate system (φ, α, R), related to the non-deformed cornea, and a spherical coordinate system (φ′, α′, R′) for the cornea that is placed against the contact surface and deformed:
• ϕ
• =
• ϕ
• ′
• α
• ′
• ·
• R
• ′
• =
• R
• ·
• (
• α
• +
• c
• 5
• 40
• 
• α
• 5
• -
• c
• 7
• 84
• 
• α
• 7
• +
• K
• 1
• )
• R
• ′
• =
• R
• KGL
• +
• R
• -
• R
• cv
• 
• (
• 1
• +
• f
• 4
• 8
• 
• α
• 4
• -
• f
• 6
• 12
• 
• α
• 6
• +
• K
• 2
• )
• wherein RKGL is the radius of the contact surface, RCV is the radius of the non-deformed anterior surface of the cornea, c5, c7, f4 and f6 are experimentally established correction factors that can be equated approximately to 1, K1 is a first optional correction term for higher odd orders of α, and K2 is a second optional correction term for higher odd orders of α.

A method of eye-surgery eye-surgery treatment that, by application of a laser device, separates tissue layers in the cornea of the eye, comprising:

• pressing a contact glass having a contact surface against the cornea, such that the contact glass deforms the cornea to conform to the shape of the contact surface;
• generating control data for the laser device such that the control data specifies target point coordinates for the laser device that are located in the cornea;
• and,
• taking into account, in the generation of the target-point coordinates, the deformation of the cornea, caused by the contact glass, that exists during the operation of the laser device;
• wherein the taking into account the deformation of the cornea comprises using the following transformation, between a spherical coordinate system (φ, α, R), related to the non-deformed cornea, and a spherical coordinate system (φ′, α′, R′) for the cornea that is placed against the contact surface and deformed:
• φ=φ′
• α′)RKGL−F′−L)=α(RCV−L)
• R′=R+RKGL−RCV
• wherein RKGL is a radius of the contact surface, RCV is a radius of the non-deformed anterior surface of the cornea, F′ is a thickness of a fluid film between the cornea and the contact surface pressed against it, and L is a displacement of a bend line of the cornea of the eye from the surface of the cornea into the interior of the cornea, which displacement has been determined experimentally, F′ or L being equated approximately to zero.