An initial treatment pattern defining an initial volume of ocular tissue to be modified for treating glaucoma is designed. An initial laser treatment is delivered by scanning a laser beam across ocular tissue at an initial placement in the eye in accordance with the initial treatment pattern to thereby photo disrupt the initial volume of ocular tissue. A postoperative measure of intraocular pressure (IOP) is evaluated relative to an IOP criterion to determine if the treatment was successful. If the treatment was not successful, meaning the IOP criterion was not satisfied, then a subsequent treatment pattern that defines a subsequent volume of ocular tissue to be modified, and/or a subsequent placement in the eye is determined. A subsequent laser treatment is delivered by scanning a laser beam across ocular tissue at the subsequent placement within the eye in accordance with the subsequent treatment pattern to thereby photo disrupt the subsequent volume of ocular tissue.

A magnetic positioning system and related method for automated or assisted eye-docking in ophthalmic surgery. The system includes a magnetic field sensing system on a laser head and a magnet on a patient interface to be mounted on the patient's eye. The magnetic field sensing system includes four magnetic field sensors located on a horizontal plane for detecting the magnetic field of the magnet, where one pair of sensors are located along the X direction at equal distances from the optical axis of the laser head and another pair are located along the Y direction at equal distances from the optical axis. Based on relative magnitudes of the magnetic field detected by each pair of sensors, the magnetic field sensing system determines whether the patient interface is centered on the optical axis. The system controls the laser head to move toward the patient interface until the latter is centered on the optical axis.

An ophthalmic laser system uses a non-confocal configuration to determine a laser beam focus position relative to the patient interface (PI) surface. The system includes a light intensity detector with no confocal lens or pinhole between the detector and the objective lens. When the objective focuses the light to a target focus point inside the PI lens at a particular offset from its distal surface, the light signal at the detector peaks. The offset value is determined by fixed system parameters, and can also be empirically determined by directly measuring the PI lens surface by observing the effect of plasma formation at the glass surface. During ophthalmic procedures, the laser focus is first scanned insider the PI lens, and the target focus point location is determined from the peak of the detector signal. The known offset value is then added to obtain the location of the PI lens surface.

An ophthalmic laser system uses a non-confocal configuration to determine a laser beam focus position relative to the patient interface (PI) surface. The system includes a light intensity detector with no confocal lens or pinhole between the detector and the objective lens. When the objective focuses the light to a target focus point inside the PI lens at a particular offset from its distal surface, the light signal at the detector peaks. The offset value is determined by fixed system parameters, and can also be empirically determined by directly measuring the PI lens surface by observing the effect of plasma formation at the glass surface. During ophthalmic procedures, the laser focus is first scanned insider the PI lens, and the target focus point location is determined from the peak of the detector signal. The known offset value is then added to obtain the location of the PI lens surface.

Calibration of laser pulse powers used to form subsurface optical structures in an ophthalmic lens is accomplished via generation of a feedback signal indicative of pulse energy absorption. A system for forming subsurface optical structures within an ophthalmic lens includes a laser pulse source, a laser pulse power control assembly, a scanning assembly, a detector, and a control unit. The laser pulse power control assembly is operable to selectively control an energy of respective laser pulses. The detector is configured to generate a feedback signal indicative of an energy absorbed by the ophthalmic lens from a first laser pulse. The control unit is configured to control operation of the laser pulse power control assembly to selectively control an energy of a second laser pulse based on a selected energy of the second laser pulse, a selected energy of the first laser pulse, and the feedback signal.

A laser system calibration method and system are provided. In some methods, a calibration plate may be used to calibrate a video camera of the laser system. The video camera pixel locations may be mapped to the physical space. A xy-scan device of the laser system may be calibrated by defining control parameters for actuating components of the xy-scan device to scan a beam to a series of locations. Optionally, the beam may be scanned to a series of locations on a fluorescent plate. The video camera may be used to capture reflected light from the fluorescent plate. The xy-scan device may then be calibrated by mapping the xy-scan device control parameters to physical locations. A desired z-depth focus may be determined by defining control parameters for focusing a beam to different depths. The video camera or a confocal detector may be used to detect the scanned depths.

Refractive index writing system and methods employing a pulsed laser source for providing a pulsed laser output at a first wavelength; an objective lens for focusing the pulsed laser output to a focal spot in an optical material; a scanner for relatively moving the focal spot with respect to the optical material at a relative speed and direction along a scan region for writing one or more traces in the optical material defined by a change in refractive index; and a controller for controlling laser exposures along the one or more traces in accordance with a calibration function for the optical material to achieve a desired refractive index profile in the optical material. The refractive index writing system may be for writing traces in in vivo optical tissue, and the controller may be configured with a calibration function obtained by calibrating refractive index change induced in enucleated ocular globes. A real-time process control monitor for detecting emissions from the optical material transmitted through the objective lens at a second wavelength may further be employed while writing the one or more traces.

In a laser cataract procedure that also corrects for astigmatism, an iris registration method compares an iris image of a patient's eye taken when the eye is not docked to a patient interface device with an iris image of the same eye that is docked to the patient interface, to calculate a rotation angle between the two images. The astigmatism axis of the eye is measured when the eye is not docked, and the measured axis is rotated by the calculated rotation angle to obtain a rotated astigmatism axis relative to the iris image of the docked eye. The laser cataract procedure is performed based on the rotated astigmatism axis. The rotation angle is calculated by optimizing a transformation that transforms the undocked iris image to match the docked iris image, where the transformation includes a dilation factor that accounts for different pupil dilation of the two iris images.

An initial treatment pattern defining an initial volume of ocular tissue to be modified for treating glaucoma is designed. An initial laser treatment is delivered by scanning a laser beam across ocular tissue at an initial placement in the eye in accordance with the initial treatment pattern to thereby photo disrupt the initial volume of ocular tissue. A postoperative measure of intraocular pressure (IOP) is evaluated relative to an IOP criterion to determine if the treatment was successful. If the treatment was not successful, meaning the IOP criterion was not satisfied, then a subsequent treatment pattern that defines a subsequent volume of ocular tissue to be modified, and/or a subsequent placement in the eye is determined. A subsequent laser treatment is delivered by scanning a laser beam across ocular tissue at the subsequent placement within the eye in accordance with the subsequent treatment pattern to thereby photo disrupt the subsequent volume of ocular tissue.

A measurement apparatus for measuring a laser focus spot size, which includes a two-dimensional image detector and an imaging system which forms a magnified image of a focus spot located an object plane onto the image detector. The imaging system includes at least an objective lens. A sealed liquid container is secured over a part of the objective lens such as the optical surface of the objective lens is immersed in the liquid (e.g. water) within the container. The liquid container has a window through which the laser beam enters. An image processing method is also disclosed which processes the image obtained by the image detector to obtain the focus spot size while implementing an algorithm that corrects for the effect of ambient vibration.