Apparatus for working on eye tissue by means of a pulsed laser beam
For the purposes of working on eye tissue, an ophthalmological apparatus comprises a laser source that is configured to produce a pulsed laser beam, a focusing optical unit that is configured to focus the pulsed laser beam into the eye tissue, and a scanner system for deflecting the pulsed laser beam onto work target points in the eye tissue. A circuit controls the scanner system in such a way that the scanner system guides the pulsed laser beam into work trajectories that extend next to one another, in order, initially, to produce cut trajectories, separated by remaining tissue bridges, of a tissue cut to be undertaken in an area and in order, thereafter, to guide the pulsed laser beam in the remaining tissue bridges between the cut trajectories in order to complete the tissue cut.
1. Ophthalmological apparatus for working on eye tissue, comprising:
a laser source configured to produce a pulsed laser beam;
a focusing optical unit configured to focus the pulsed laser beam into the eye tissue; and
a scanner system configured to guide the pulsed laser beam onto work target points in the eye tissue;
wherein the ophthalmological apparatus further comprises a circuit configured to control the scanner system in such a way that the scanner system guides the pulsed laser beam onto work target points on a lower outer face of a lenticule to be cut in a cornea, facing away from an outer corneal surface, in work trajectories that extend next to one another, in order, initially, to produce cut trajectories, separated by remaining tissue bridges, of a lower tissue cut on the lower outer face of the lenticule, and
wherein the circuit further is configured to control the scanner system in such a way that the scanner system thereupon guides the pulsed laser beam onto work target points on an upper outer face of the lenticule, facing the outer corneal surface, in work trajectories extending next to one another, in order to produce cut trajectories, separated by remaining tissue bridges, of an upper tissue cut on the upper outer face of the lenticule,
before the scanner system guides the pulsed laser beam onto work target points into the remaining tissue bridges between the cut trajectories on the lower outer face of the lenticule, in order to complete the lower tissue cut, and
wherein the circuit further is configured to control the scanner system in such a way that the scanner system thereupon guides the pulsed laser beam onto work target points into the remaining tissue bridges on the upper outer face of the lenticule, in order to complete the upper tissue cut.
2. Ophthalmological apparatus according to claim 1 , wherein the ophthalmological apparatus comprises a measurement system that is configured to optically capture structures in the eye tissue; and the circuit is configured to control the measurement system in such a way that the measurement system captures the produced cut trajectories of the lower tissue cut to be undertaken, and to position, in respect of the captured cut trajectories of the lower tissue cut, the work trajectories of the upper tissue cut to be undertaken.
3. Ophthalmological apparatus according to claim 2 , wherein the circuit is configured to determine the work trajectories of the upper tissue cut to be undertaken with a smaller trajectory width in respect of the captured cut trajectories of the lower tissue cut.
4. Ophthalmological apparatus according to claim 3 , wherein the circuit is configured to position the work trajectories for completing the lower tissue cut in relation to the captured cut trajectories of the lower tissue cut.
5. Ophthalmological apparatus according to claim 2 , wherein the circuit is configured to position the work trajectories for completing the lower tissue cut in relation to the captured cut trajectories of the lower tissue cut.
6. Ophthalmological apparatus according to claim 2 , wherein the measurement system is embodied as an interferometric measurement system.
7. Ophthalmological apparatus according to claim 1 , wherein the circuit is configured to control the scanner system in such a way that the scanner system guides the pulsed laser beam with overlapping laser pulse spots onto successive work target points.
8. Ophthalmological apparatus according to claim 1 , wherein the circuit is configured to control the scanner system in such a way that the scanner system guides the pulsed laser beam onto work target points in the work trajectories extending next to one another into the remaining tissue bridges.
9. Ophthalmological apparatus according to claim 8 , wherein the circuit is configured to control the scanner system in such a way that the scanner system guides the pulsed laser beam in the remaining tissue bridges onto work target points in work trajectories which have a width going beyond the tissue bridges.
10. Ophthalmological apparatus according to claim 1 , wherein the circuit is configured to control the scanner system in such a way that the scanner system guides the pulsed laser beam onto work target points in work trajectories that extend parallel next to one another.
11. Ophthalmological apparatus according to claim 1 , wherein the circuit is configured to control the scanner system in such a way that the scanner system guides the pulsed laser beam onto work target points in work trajectories that extend next to one another, said work trajectories having one of the following forms: spiral, circular and elliptical.
12. Ophthalmological apparatus according to claim 1 , wherein the circuit is configured to control the scanner system in such a way that the scanner system guides the pulsed laser beam in a feed direction onto work target points along a work line extending in the work trajectories and the scanner system is configured to guide the pulsed laser beam along a scan line, extending across the work line, within the work trajectories with a substantially higher scan speed in comparison with the scan speed in the feed direction.