Re-treatment for ophthalmic correction of refraction
A planning device generating control data for a treatment apparatus for refraction-correcting ophthalmic surgery is provided, said apparatus using a laser device to separate a corneal volume, which is to be removed for correction, from the surrounding cornea by at least one cut surface in the cornea of an eye, said planning device comprising an interface for receiving corneal data including information on pre-operative cuts which were generated in a previous ophthalmic operation, and computing means for defining a corneal cut surface which confines the corneal volume to be removed, said computing means defining the corneal cut surface on the basis of the corneal data and generating a control dataset for the corneal cut surface for control of the laser device.
1. A system for performing ophthalmic surgery in tissue of an eye after at least one previous ophthalmic surgery in the tissue, comprising:
a treatment apparatus comprising a laser device configured to generate at least one cut surface in the tissue by deflecting a laser beam in the eye; and
a planning station configured to:
access information on at least one pre-operative cut generated in the at least one previous ophthalmic surgery;
define a cut surface on a basis of the information on the at least one pre-operative cut;
generate a control dataset describing the cut surface in terms of treatment apparatus control, and
transmit the control dataset to the treatment apparatus, wherein the laser device comprises a laser source emitting the laser beam as a pulsed laser beam having a pulse duration in a range of between 1 fs and 10 ps,
wherein said planning station is configured to generate the control dataset for a re-treatment of the previous ophthalmic surgery which left the at least one pre-operative cut in the tissue.
2. The system as claimed in claim 1 , wherein the laser beam has a pulse energy of between 0.01 μJ and 0.01 mJ.
3. The system according to claim 1 , wherein the tissue of the eye is a cornea and the planning station is configured to define the cut surface to confine corneal volume which is to be removed to correct a refraction error of the eye.
4. The system as claimed in claim 1 , wherein the cut surface continues the at least one pre-operative cut.
5. The system of claim 1 , further comprising at least one of the following measurement devices: OCT, refractometer, keratometer, abberometer, and wave-front measurement device, which in particular generates the information on the at least one pre-operative cut generated in the at least one previous ophthalmic surgery.
6. The system as claimed in claim 1 , wherein the tissue of the eye is a cornea and the cut surface comprises an opening cut leading to an anterior surface of the cornea.
7. The system as claimed in claim 1 , wherein the cut surface confines defective material of a cornea which material is to be removed.