Method and system for modifying eye tissue and intraocular lenses
As shown in the drawings for purposes of illustration, a method and system for making physical modifications to intraocular targets is disclosed. In varying embodiments, the method and system disclosed herein provide many advantages over the current standard of care. Specifically, linear absorption facilitated photodecomposition and linear absorption facilitated plasma generation to modify intraocular tissues and synthetic intraocular lenses.
1. A system for ophthalmic surgery, the system comprising:
a laser system comprising an optical system and a laser source configured to deliver a laser beam, the laser beam comprising a plurality of laser pulses having a pulse energy between 0.01 microJoules and 500 microJoules, a pulse duration between 400 picoseconds and 700 picoseconds, and a wavelength between 320 nanometers and 370 nanometers, the optical system being operatively coupled to the laser source and configured to focus the laser beam to a focal spot and scan the focal spot; and
control electronics operatively coupled to the laser system and configured to operate the laser system to scan the focal spot in a pattern in a lens capsule of a patient's eye, wherein the pattern defines one or more capsulotomies in the lens capsule, and wherein the pulse energy, the pulse duration, and the focal spot are configured such that the laser beam irradiance at the focal spot is sufficiently high to physically modify the lens capsule by photodecomposition but not exceeding a threshold of formation of a plasma and associated cavitation event.
2. The system of claim 1 , wherein the wavelength is 355 nanometers.
3. The system of claim 1 , wherein the pulse duration is 400 picoseconds.
4. The system of claim 1 , wherein the pulse energy is between 0.5 microJoules and 10 microJoules.
5. The system of claim 1 , wherein the plurality of laser pulses have a repetition rate of between 500 Hertz and 500 kiloHertz.
6. The system of claim 1 , wherein the focal spot has a size between 0.5 microns and 10 microns.
7. The system of claim 1 , wherein the laser beam irradiance is 120 gigaWatts per square centimeter.
8. The system of claim 1 , further comprising:
a confocal imaging subsystem configured to perform confocal reflectometry;
wherein the control electronics are further configured to operate the confocal imaging subsystem to monitor for the occurrence of a cavitation event associated with formation of plasma, and to reduce pulse energy of subsequent laser pulses in response to detection of a cavitation event to avoid cavitation.
9. The system of claim 1 , wherein the lens capsule contains an exogenous chromophore configured to enhance linear absorption of the laser pulses by the lens capsule.
10. The system of claim 1 , wherein the control electronics are configured to focus the laser beam on the lens capsule at a maximal depth defined by the pattern and then focus the laser beam in the lens capsule at a more shallow depth to avoid laser beam scattering on bubbles, cracks and/or tissue fragments prior to reaching the focal point.