Photodisruptive laser fragmentation of tissue
View Patent ↗An ophthalmic laser surgical system includes a pulsed laser source configured to generate a pulsed laser beam, optics configured to direct the laser beam towards a target region in a lens of an eye, and a processor configured to control the optics to form a regular array of cells in the target region by creating layers of photodisrupted bubbles to generate cell boundaries. The layers are created by causing the optics to scan the pulsed laser according to a curvature of a focal plane of the optics to track a natural curvature of the lens.
1. An ophthalmic laser surgical system, comprising:
a pulsed laser source configured to generate a pulsed laser beam;
an imaging device configured to capture image data and measure structural properties of a lens of an eye;
an optics module with optics configured to direct the laser beam towards a plurality of target regions in the lens of the eye, wherein the laser beam is applied as a plurality of spots at the target regions, wherein the plurality of spots are generated in a laser pattern with a spot separation selected based on the structural properties of the lens, wherein at least a portion of the target regions include a bulk portion of the lens having concentric layers of elongated fibers; and
a system control module configured to control, based on the image data and the structural properties of the lens, the optics module to form an array of cells in the target region by creating a plurality of layers of photodisrupted bubbles and a plurality of walls of photodisrupted bubbles to generate cell boundaries, wherein the system control module is further configured to control the optics module to direct pulsed laser source to generate the laser pattern with a spot separation with a higher spot density and/ or a higher laser pulse energy to form cell boundaries that are perpendicular to the elongated fibers, as compared to when the cell boundaries are located parallel to elongated fibers.
2. The system of claim 1 , wherein the array of cells are of a size suitable for extraction by aspiration without manual lens fragmentation.
3. The system of claim 1 , wherein a spatial extent of the array of cells is less than 340 microns.
4. The system of claim 1 , wherein the array of cells comprises cells greater than 50 microns.
5. The system of claim 1 , wherein the array of cells includes a set of cells in a periodically repeating array.
6. The system of claim 1 , wherein the array of cells comprises cells greater than 250 microns.
7. The system of claim 1 , wherein the system control module is configured to control the optics to form the bubbles with a spot separation of less than 20 microns.
8. The system of claim 1 , wherein the system control module is configured to control the optics module to reduce a linear speed of progression of a bubble placement at turning points to a speed that is smaller than a limiting value, a turning point being a point where there is a change in direction.