Amo Development, LLC

Mohammad Saidur Rahaman

Hong Fu

Zenon Witowski

Roger W Accurso

Alireza Malek Tabrizi

James E Hill

Harvey I Liu

Daryl Wong

Griffith E Altmann

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.

Detection of optical surface of patient interface for ophthalmic laser applications using a non-confocal configuration

Embodiments generally relate to ophthalmic laser procedures and, more particularly, to systems and methods for lenticular laser incision. In an embodiment, an ophthalmic surgical laser system comprises a laser delivery system for delivering a pulsed laser beam to a target in a subject's eye, an XY-scan device to deflect the pulsed laser beam, a Z-scan device to modify a depth of a focus of the pulsed laser beam, and a controller configured to form a top lenticular incision and a bottom lenticular incision of a lens in a corneal stroma.

Methods for lenticular laser incision

An ophthalmic laser surgical system has a built-in imaging sensor for measuring laser focal spot size. An objective lens focuses the laser beam to a focal spot near a reflective surface, scans the focal spot in the depth direction, and focuses light reflected by the reflective surface to form a back-reflected light. A two-dimensional imaging sensor receives a sample of the back-reflected light to generate images of the back-reflected light. During the depth scan, the image contains a well-focused light spot when the laser focal spot is located at a fixed offset distance before the reflective surface, but the light spot in the images is otherwise defocused. The images generated during the scan are analyzed to find the smallest light spot size among the images. The laser focal spot size is then calculated from the smallest light spot size using a magnification factor which is a system constant.

Laser focal spot size measurement using a built-in camera for an ophthalmic laser system

In a laser beam delivery system for an ophthalmic laser system, a single multi-use beam sampler is employed to form three sampled laser beams, including two for redundant laser energy monitoring and one for laser focal point depth measurement. The beam sampler is a transparent plate with preferably parallel front and back surfaces. The front surface reflects a fraction of the incoming beam to form the first sampled beam toward an energy monitoring detector. The back surface reflects another fraction of the beam to form a second sampled beam exiting backwardly from the front surface toward another energy monitoring detector. An objective lens focuses the transmitted beam onto a target, and collects back reflected or scattered light from the target to form a return beam. The back surface of the beam sampler reflects a fraction of the return beam to form the third sampled beam toward a third detector.

Multi-use beam sampler in laser beam delivery path of ophthalmic laser system

An imaging system for an ophthalmic laser system includes a prism cone made of a transparent optical material and disposed downstream of the focusing objective lens of the ophthalmic laser system, the prism cone having an upper surface, a lower surface parallel to the upper surface, a tapered side surface between the upper and lower surfaces, and a beveled surface formed at an upper edge of the prism cone and intersecting the upper surface and the side surface, and a camera disposed adjacent to the prism cone and facing the beveled surface. The camera is disposed to directly receive light that enters the lower surface of the prism cone and exits the beveled surface without having been reflected by any surface.

Imaging device for ophthalmic laser system using off-axis miniature camera

An ophthalmic laser surgical system uses a confocal detector assembly to continuously detect a confocal signal during laser treatment, and based on the confocal signal, detects in real time a loss of tissue contact with the patient interface (PI) output surface. The detection is partly based on the change of reflectivity at the PI output surface when the optical interface changes from a lens-tissue interface to a lens-air interface. The behavior of the confocal signal upon loss of tissue contact is dependent on the treatment laser scan pattern being performed at the time of tissue contact loss. Thus, different confocal signal analysis algorithms are applied to detect tissue contact loss during different scans, such as the bed cut and side cut for a corneal flap. The real time confocal signal may also be used during eye docking to detect the establishment of tissue contact with the PI output surface.

Eye suction loss and corneal applanation detection in ophthalmic docking system using optical signal

A femtosecond laser system for ophthalmic applications, which employs a number of chirped mirrors in the laser beam delivery system between the laser head and the objective lens. The chirped mirrors perform the dual function of both turning the laser beam in desired directions and compensating for beam broadening due to group delay dispersion (GDD) of the optical elements of the system. Each chirped mirror reflects the laser beam only once. Four chirped mirrors are used, each providing up to &#x2212;5000 fsof negative GDD per bounce, to provide a total of &#x2212;18,000 fsnegative GDD to compensate for the positive GDD of +18,000 fsintroduced by other optical elements in the laser beam delivery system. This eliminates the need for a pulse compressor that would employ a grating pair, prism pair or grism pair, and therefore significantly reduces the size of the system and the alignment requirements.

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Santa Clara, CA, United States of America

Mohammad Saidur Rahaman