AMO DEVELOPMENT, LLC

A counterbalance mechanism in an ophthalmic laser system balances the weight of the laser beam delivery head and provides small, precise and repeatable variations in the net load exerted by the laser head on the patient's eye over a defined distance of travel. The counterbalance mechanism includes a balance beam pivotably mounted on a support block, with the laser head and a counterweight mounted on its two ends. The counterweight is movable along the balance beam via a linear motion bearing. A mechanical link links the counterweight to the support block; the link has a predefined length and is pivotable around its respective connection points on the support block and the counterweight. When the balance beam pivots, the link causes the counterweight to move along the balance beam, thereby changing the mechanical advantage of the counterweight and varies the counterbalancing force to provide variations in the net load.

In a femtosecond ophthalmic laser system which employs a high frequency resonant scanner to produce a laser scanline and XY and Z scanners to move the scanline in a patient's eye to perform eye surgery, a beam blocking member is placed near an internal focus plane of the optical system to block some of the beam paths to truncate the laser scanline at the two ends. This eliminates the closely spaced or overlapping laser focus spots near the ends of the scanline. The beam blocking member has a plate shape with one or more apertures of different shapes or sizes, and is movable in the transverse direction to different positions to block different amounts of the scanline.

A method implemented in an ophthalmic surgical laser system for forming a corneal flap in a patient's eye with improved bubble management. The flap includes a horizontal bed and a vertical or near vertical side cut around the periphery of the bed except for an uncut hinge area. The side cut has a bubble barrier layer that can prevent bubbles formed by the laser-tissue interaction from escaping into an interface between the corneal and the patient interface lens. In some embodiments, the bubble barrier layer is a thin uncut layer, located in the epithelium of the cornea, that separates the side cut into two portions. In other embodiments, the side cut does not reach the anterior corneal surface, leaving an uncut bubble barrier layer located with the epithelium. In other embodiments, an additional side cut portion is formed through the uncut bubble barrier layer as the last step.

A fiducial is generated on an internal anatomical structure of the eye of a patient with a surgical laser. A toric artificial intraocular lens (IOL) is positioned so that a marker of the toric IOL is in a predetermined positional relationship relative to the fiducial. This positioning aligns the toric IOL with the astigmatic or other axis of the eye. The toric IOL is then implanted in the eye of the patient with high accuracy.

A ophthalmic laser-assisted corneal lenticule extraction procedure that uses wavefront measurements to guide the formation of the corneal lenticule. The wavefront map measured from a free eye using a wavefront aberrometer is registered to the cornea of a docked eye based on comparisons of iris images and corneal markings. The docked-eye cornea-registered wavefront map is then corrected to be consistent with the Munnerlyn formula for the spherical power, and adjusted for any physician adjustments and/or myopia error due to a flat add in the lenticule, using Zernike polynomials. The corrected and adjusted wavefront map is then used to calculate the profiles of the bottom and top lenticule incisions in the applanated cornea, where higher-order components in the wavefront map are distributed to the bottom lenticule incision alone and lower-order components in the wavefront map are distributed to both the bottom and the top lenticule incision.

Two pupil detection methods implemented in an ophthalmic laser surgery system for detecting the pupil of the patient's eye both before and after the eye is applanated by a patient interface device. In the first method, an infrared image is captured before the eye is coupled to the patient interface. After excluding certain image artifacts, the pixel intensity is clustered into four clusters, and pixels belonging to the cluster with the lowest intensity are deemed pupil pixels, and pupil boundary and pupil center are determined accordingly. In the second method, a color image is captured after the eye is coupled to the patient interface. The color image is converted to the HSV color space, and only the hue channel is used for pupil detection. The hue channel image is filtered by median filtering and edge-preserving filtering (e.g. guided image filtering), then binarized, before pupil detection is performed.

Apparatus and method for interfacing an ophthalmic surgical laser system with a patient's eye using a single-piece patient interface (PI). The PI includes a hollow shell, with an applanation lens and a flexible skirt at its lower end. Through channels are formed around the applanation lens to connect the spaces above and below the lens. When the PI is coupled to the laser system and the eye, the upper rim of the shell forms a seal with the laser system and the flexible skirt forms a seal with the eye. A vacuum is applied to the interior of the shell via a vacuum port on the laser system, and the vacuum is communicated to the space enclosed by the applanation lens, the skirt and the eye through the channels around the lens. A magnetic mechanism is also provided to hold the PI shell to the laser system.

Devices, systems, and methods that facilitate optical analysis, particularly for the diagnosis and treatment of refractive errors of the eye. An optical diagnostic method for an eye includes obtaining a sequence of aberration measurements of the eye, identifying an outlier aberration measurement of the sequence of aberration measurements, and excluding the outlier aberration measurement from the sequence of aberration measurements to produce a qualified sequence of aberration measurements. The sequence of aberrations measurements can be obtained by using a wavefront sensor. An optical correction for the eye can be formulated in response to the qualified sequence of aberration measurements.

A method implemented in an ophthalmic laser system to perform iris registration based on two iris images taken with the patient at upright and supine positions, respectively. For each iris image, the iris region is transformed into a rectangular rubbersheet, with the radial and angular coordinates of the iris image respectively mapped to vertical and horizontal coordinates of the rubbersheet. A horizontal one-dimensional log-Gabor transform is applied to the rubbersheet line-by-line. The transformed rubbersheet is binarized line-by-line. The two binary rubbersheets are compared at a series of relative horizontal shifts to determine the horizontal shift value that produces the lowest Hamming distance between the two binary rubbersheets, and the cyclotorsion rotation of the eye between the upright and supine positions is calculated accordingly. Then, while the patient is in the supine position, the laser system treats the eye based on measured astigmatism axis orientation and the calculated cyclotorsion rotation.

A single-piece patient interface device for coupling a patient's eye to an ophthalmic surgical laser system includes a cone substrate with a rigid frustoconical shaped shell for coupling to the laser system, and a flexible suction ring integrally joined to the lower end of the rigid shell for coupling to the patient's eye. The suction ring has a circular skirt extending downwardly from a base portion, a diaphragm extending from the base portion and disposed inside of the skirt, and a contact lens held by the diaphragm to cover a center opening. When the skirt contacts the eye's surface, the skirt, the diaphragm, the contact lens and the eye surface form a vacuum chamber, where a vacuum may be applied to secure the patient interface device to the eye. The parameters of the suction ring are optimized to fit a large range of eye sizes, including smaller eyes.