51 results about "Keratorefractive surgery" patented technology

An intraocular light probe has a mask or shield affixed at its distal end thereof which forms a directed light beam for intraocular illumination of target tissues or intraocular application of therapeutic light. The mask or shield serves to more fully focus, intensify and direct the beam toward the target tissues. The mask or shield also helps direct light away from other tissues and away from the eyes of the surgeon. This lessens unwanted glare. By placing a light probe beneath a surgical instrument such as a phacoemulsifier or vitrector, laser, cutting instrument (e.g., scissors or knife), forceps or probe/manipulator, whether as part of or separate from an infusion sleeve, a mask or shield effect is created. This has the same benefits of directing the beam toward target tissues, away from other tissues and away from the eyes of the surgeon. The mask or shield is opaque or semi-opaque and made of a soft, semi-rigid or rigid material. The shield can be rigid enough to serve as the shaft of an instrument with a probe or manipulator at its distal tip. It may also be reflective on the side adjacent to the fiber bundle to help direct, magnify, and intensify the beam of light. The shape of the shield can be flat, curved or circular with an opening along one side. The mask/shield can be removed from the fiberoptic light for sterilization. The device of the invention is preferably introduced into the eye via the primary or side-port incision to provide intraocular cross-lighting of tissues during surgical procedures such as cataract surgery, corneal surgery, vitrectomy, intraocular lens implantation, refractive surgery, glaucoma surgery and vitreo/retinal surgery.

A method and apparatus for intrastromal refractive surgery is disclosed wherein tissue at selected locations within the stroma of the cornea is photoablated using a pulsed laser beam. The apparatus includes an optical system for forming a shaped laser beam having a waist at a predetermined distance from the optical system. The pulse duration and pulse energy of the laser beam are selected to cause ablation to occur in front of the waist (i.e. between the waist and the optical system). To achieve this, a pulse energy is used that exceeds the minimum pulse energy required for ablation at the waist. By ablating in front of the waist, a relatively large ablation zone (per pulse) is created (compared to ablation at the waist). Furthermore, while the laser is scanned through the cornea to effectuate a refractive change, the optical system maintains a uniform waist for the laser beam.

A new type of multi-focal lens that has a free-form progressive multifocal front surface consisting of a 16th order polynomial superimposed on a standard conic base surface is described. The center region of the lens is optimized for distance vision, while simultaneously optimizing the rest of the lens for near vision. The resulting free-form even asphere polynomial surface is smooth, unlike present day diffractive multifocal designs. Additionally, this lens design is suitable for both refractive and cataract surgeries.

A novel method and apparatus are provided for correcting an off-center laser ablation in the cornea, in which the original ablated area has a center that is offset from the correct center of the optical cornea. The method comprises the steps of determining the correct optical center of the cornea and the offset location of the ablation; performing a supplemental laser ablation on the cornea with the laser beam covering generally the original ablated area, and with the energy of the supplemental laser increasing in a direction from the offset center toward the correct center; introducing a laser shield to cover the entire original ablated area; and performing another laser ablation with the correct optical center as the center of the ablated area.

The present invention is directed to a solution for measuring geometric parameters in the eye which are required for calculating the refractive power of intraocular lenses. The device according to the invention for axial length measurement which acquires axial length, anterior corneal radii, anterior chamber depth, and other parameters in the anterior eye segment includes a control unit, a first measuring device for determining axial length, and an additional measuring device which acquires a plurality of structures in the anterior segment (such as the cornea, anterior chamber, and lens) and which has at least one illumination unit and at least one image recording unit. By determining additional partial-distance parameters of the anterior eye segments, the IOL can be calculated with high precision even after refractive surgery in which the natural relationship between the radii of the anterior and posterior corneal surfaces is extensively altered by corneal surgery.

One embodiment is a method for finding, calculating and electronically marking a reference axis for astigmatism correction/neutralization of a patient eye during a refractive surgery.

The reference axis for astigmatism correction/neutralization can be determined intra-operatively based on one or more eye property measurements together with simultaneous recording a live eye image. The determined reference axis of astigmatism correction/neutralization can be updated and registered with one or more land mark(s) of the recorded eye image(s); and overlaid onto a live image of the eye. Another embodiment is a method of calculating and displaying in real time compensated refractive errors of the eye under operation with refractive components due to temporary surgically induced factors removed and refractive components due to surgeon-induced factors added.

This invention is generally related to vision corrections by means of multifocal ophthalmic lenses or by means of corneal refractive surgery. In particular, the present invention provides a multifocal contact lens, a multifocal intraocular lens, a method for making a multifocal ophthalmic lens (contact lens and intraocular lens), and a method of correcting presbyopia by reshaping the cornea of an eye.

A method and surgical technique for corneal reshaping and for presbyopia correction are provided. The preferred embodiments of the system consists of a scanner, a beam spot controller and coupling fibers and the basic laser having a wavelength of (190-310) nm, (0.5-3.2) microns and (5.6-6.2) microns and a pulse duration of about (10-150) nanoseconds, (10-500) microseconds and true continuous wave. New mid-infrared gas lasers are provided for the corneal reshaping procedures. Presbyopia is treated by a method which uses ablative laser to ablate the sclera tissue and increase the accommodation of the ciliary body. The tissue bleeding is prevented by a dual-beam system having ablative and coagulation lasers. The preferred embodiments include short pulse ablative lasers (pulse duration less than 200 microseconds) with wavelength range of (0.15-3.2) microns and the long pulse (longer than 200 microseconds) coagulative lasers at (0.5-10.6) microns. Compact diode lasers of (980-2100) nm and diode-pumped solid state laser at about 2.9 microns for radial ablation patterns on the sclera ciliary body of a cornea are also disclosed for presbyopia correction using the mechanism of sclera expansion.

A reduction of eye trauma is achieved during opthalmolic surgery branch for implanting the intraocular refractive lens to the anterior chamber of the eye. The pupil is extended by mydriatic compounds and after anesthesia the cornea cut is made (clear cornea—3 mm). Thereafter, the anterior chamber of the eye is filled with viscoelastic compound with low molecular weight and then the refractive lens is implanted with the help of said cannula, the working face of the cannula at the middle between the lens edge and the border of the optic area, with the edge bent on the cannula face. The end by the top of the bending the refractive lens is introduced into the cornea cut and set in the posterior chamber of the eye. Thereafter, vacuum is removed and the cannula is detached from the refractive lens, and taken off the anterior chamber of the eye by the reverse movement. The refractive lens cannula is made as a tube with round or oval cross-section with inner diameter 0.5-2.5 mm and wall thickness not less than 0.05 mm. The tube is bent at 110-160, supplied with limiter, and working end that has diameter of the round cross-section of 1.0-2.0 mm or ellipse-shaped cross-section with small and big axes 0.6-0.9 mm and 1.5-2.5 mm, respectively.

A device for dissecting an eye for the introduction of photosensitizer into the cornea where laser radiation is focused in the interior of the cornea to create cavitation bubbles, whereby channels are created in the cornea through which the photosensitizer can be introduced into the cornea. Furthermore, a method for refractive surgery includes utilizing a sensitizer for hardening corneal tissue by cross-linking.

A system and method for performing refractive surgery in an eye requires creating a plurality of cuts in the stroma or the lens that are randomly positioned relative to a reference axis. The geometry for each cut is unique and includes a start point in the stroma that is identified by a distance “r” from the axis, and an azimuthal angle “θ” that is measured around the axis. A computer provides concerted control for a laser unit and an optical scanner to randomly vary the start point for each cut, to create a pattern of cuts that will implement the desired refractive surgery, yet be visually illusive.

The invention relates to a cornea center positioning method for excimer laser cornea refractive surgery. In the method, a horizontal offset model and a vertical offset model are established by measuring the pupillary diameter and the offset of the pupillary center relative to the center of the corneal vertex under different luminance brightness, and the data of the established models is input into a laser cornea refractive surgery machine with an eye tracking system, so the pupil in the laser cornea refractive surgery is dynamically tracked, the error of the tracking system is reduced, and the visual quality after the laser cornea refractive surgery is obviously improved.

Improved indices for the diagnosis and evaluation of conditions affecting the eye. Specifically, the indices include an Enhanced Epithelial Irregularity Factor (eEIF) for the diagnosis and evaluation of conditions such as dry eye syndrome (DES), Bowman's Ectasia Index (BEI), including enhanced BEI (eBEI) and BEI-Max, and Bowman's Relative Thinning (BRT) Index for the diagnosis and evaluation of ectatic conditions such as keratoconus, pellucid marginal degeneration, post-refractive surgery ectasia, and keratoglobus, and Descemet's Membrane Thickening Index (DMT), Descemet's Rejection Index (DRI), and Descemet's Membrane Irregularity Factor (DIF) for the diagnosis and evaluation of conditions such as keratoplasty rejection and failure and Fuchs' dystrophy. These improved indices may be incorporated into optical coherence tomography systems, or any other imaging device capable of capturing high resolution images of the cornea, for more sensitive and specific diagnosis, treatment, and monitoring of certain corneal conditions, in addition to the evaluation of new treatments.

The invention relates to medical instruments and methods for performing eye surgery to correct focusing deficiencies of the cornea. More particularly, the present invention relates to mechanical instruments known as microkeratomes, and related surgical methods for performing lamellar keratotomies and refractive surgery. The device is designed to create a flap of epithelium, or stroma and epithelial flap as is done now with LASIK. This will enable a new technique, ELF, or Epithelial Laser Flap, which will combine the advantages of LASIK and PRK, an older, but easier technique.

A contact lens is fitted to a cornea of a patient's eye to gradually alter the patient's cornea during continued wear to reshape the altered cornea conditions such as the corneas of post refractive surgery, post previous Ortho-K. and keratoconus. The contact lens has a plurality of zones that comprise one optical zone, at least one conformation zone, a connecting zones complex, an alignment zone and a peripheral zone. The one or more conformation zones are utilized to conform the angle of the central optical zone, as well as the alignment zone, to compress on the central and mid-peripheral portion of the altered cornea for redistribute cornea tissue to reduce the residual refractive errors, after refractive surgery, or to smooth out the central cornea surface of the keratoconus for better bare or spectacle vision after contact lens are removed.

Systems and methods for using a new corneal ratio, referred to as the Geggel ratio, to estimate how much treatment a patient received at an original myopic or mixed astigmatism excimer laser refractive surgery. The Geggel ratio represents the ratio of the measure of a pre-IOL central pachymetry to a measure of a pre-IOL superior pachymetry. The estimated laser ablation depth (ELAD) is used in a derived linear regression equation to determine an IOL power adjustment that is added to the standard SRK/T formula used to determine IOL power.

An ophthalmic instrument for measurement of ocular refraction and visual simulation and a method of measurement obtaining the ocular refraction in a binocular manner, which incorporates a digitally controlled phase modulator for generating best ophthalmic correction in each subject. The instrument enables measuring refraction, not only associated with blurring and astigmatism, but also optical aberration of any order. The phoropter can simulate vision by any phase profile, including those of a diffractive or discontinuous type. The instrument also incorporates a subsystem for presentation of stimuli that produces stereoscopic vision of the same, enabling the subject to enjoy a three dimensional perception during the process, and two output pupils. The instrument, by its electro-optical features, enables simulation of vision as it would be modified after submitting an eye to different surgical techniques, such as refractive surgery or interocular lens implantation.

A system and method for correcting a vision defect (i.e. presbyopia) of a patient requires two laser units. A first laser unit is used to photoablate (i.e. remove) tissue from the cornea for the creation of a multi-focal cornea that simultaneously provides for both near and distance vision capabilities. A second laser unit can also be used to refine the shape of the cornea by weakening selected portions with LIOB. Together, the removal and weakening of corneal tissue are regulated to optimize the resultant near vision and distant vision capabilities of the patient.