Method and apparatus for creating ocular surgical and relaxing incisions
A system and method of treating target tissue in a patient's eye, which includes generating a light beam, deflecting the light beam using a scanner to form first and second treatment patterns, delivering the first treatment pattern to the target tissue to form an incision that provides access to an eye chamber of the patient's eye, and delivering the second treatment pattern to the target tissue to form a relaxation incision along or near limbus tissue or along corneal tissue anterior to the limbus tissue of the patient's eye to reduce astigmatism thereof.
1. A method for treating target tissue in a patient's eye, comprising:
by an ultrafast laser source, generating a laser beam having a plurality of laser pulses;
by a wavefront sensing system, measuring an optical aberration of the eye;
by an Optical Coherence Tomography (OCT) device, generating signals representing an image of a cornea and limbus of the eye;
by a controller, determining a treatment pattern based upon the signals from the OCT device; and
by a scanner under control of the controller, scanning a focal point of the laser beam according to the treatment pattern to form a cataract incision in the cornea that provides access for lens removal instrumentation to a crystalline lens of the patient's eye and one or more relaxation incisions in the cornea or limbus, wherein the cataract incision has an arcuate extent of less than 360 degrees in a top view, wherein the cataract incision includes a bevel shape in a cross-sectional view, the bevel shape including a first segment and a second segment which intersect each other at an angle, the cataract incision being entirely located in the cornea and intersecting both an anterior surface and a posterior surface of the cornea.
2. The method of claim 1 , wherein at least one of the one or more relaxation incisions only partially extends through the target tissue.
3. The method of claim 1 , further comprising: by a profilometer, measuring a surface profile of a surface of the cornea of the patient's eye, wherein the controller determines the treatment pattern in response to the measured surface profile.
4. The method of claim 1 , wherein the OCT device measures scattering properties from different locations on the patient's eye, and wherein the controller determines the treatment pattern in response to the scattering properties.
5. The method of claim 1 , wherein the controller operates the laser source and scanner to create incisions within the tissue at a depth based upon the signals from the OCT device.
6. The method of claim 1 , wherein the laser beam has a wavelength between 1010 nm to 1100 nm.
7. The method of claim 1 , wherein the laser pulses have pulse lengths of 100 fs to 10000 fs.
8. The method of claim 1 , wherein the laser pulses have a pulse repetition frequency of 10 kHz to 250 kHz.
9. The method of claim 1 , wherein the step of measuring the optical aberration of the eye includes using a Shack-Hartmann wavefront sensor to measure a shape of a wavefront of light that exits the eye's pupil.
10. The method of claim 9 , wherein the step of determining a treatment pattern includes determining a correction to the shape of the cornea based on the shape of the wavefront.