Abstract:
Devices and associated methods are disclosed for treating bone, and particularly bone tissue at the joints. Disclosed are implantable devices that can be used either alone or in combination with this augmentation or hardening material for the repair of bone defects and which are particularly suited for use at the joints, and even more particularly, suited for use at the subchondral bone level.
Abstract:
A method and system for measuring an optical property of a multi-focal lens are disclosed. One embodiment of the method comprises: filtering out light transmitted by all but one of a plurality of diffraction orders of the lens to provide an unfiltered light from a single diffraction order; receiving the unfiltered light at a wavefront detector; and analyzing the unfiltered light at the wavefront detector to measure the optical property. The multi-focal lens can be a multi-focal diffractive intra-ocular lens. The measured optical property can be a discontinuity in the lens surface. Filtering can comprise blocking all but the unfiltered light using an aperture operable to let through the unfiltered light from the single diffraction order, and/or blocking all but the unfiltered light using an opaque obstruction operable to let through only a selected amount of light corresponding to the light transmitted by the single diffraction order. The method can further comprise generating an image quality parameter, such as a modulation transfer function, based on the measured optical property.
Abstract:
A method for measuring the optical properties of multifocal ophthalmic lenses. Collimated light is passed through an ophthalmic lens and onto an array of lenslets. Light exiting the array of lenslets is detected by a sensor. Blurred spots and/or double spots may represent diffractive zones of the wavefront. A centroid of the spot or a brighter of two spots may be used to determine the lateral position of the spot. Theoretical calculations, laboratory measurements, clinical measurements and experimental image spots may be generated, compared and cross-checked to determine a monofocal equivalent lens. A Modulation Transfer Function (MTF) may be used to evaluate and compare a diffractive lens and a monofocal equivalent lens.
Abstract:
A method for measuring the optical properties of multifocal ophthalmic lenses. Collimated light is passed through an ophthalmic lens and onto an array of lenslets. Light exiting the array of lenslets is detected by a sensor. Blurred spots and/or double spots may represent diffractive zones of the wavefront. A centroid of the spot or a brighter of two spots may be used to determine the lateral position of the spot. Theoretical calculations, laboratory measurements, clinical measurements and experimental image spots may be generated, compared and cross-checked to determine a monofocal equivalent lens. An MTF may be used to evaluate and compare a diffractive lens and a monofocal equivalent lens.
Abstract:
In one aspect, the invention provides an intraocular lens (IOL) that includes an optic and a peripheral optical flange that surrounds the optic. The optic can form an image of a field of view on the IOL user's retina and the peripheral flange can inhibit dysphotopsia. By way of example, the peripheral flange can include at least one textured surface that is adapted to receive peripheral light rays entering the eye at large visual angles so as to cause their scattering in order to inhibit dysphotopsia, e.g., by preventing the formation of a secondary peripheral image or scattering some light to a shadow region between such a secondary image and an image formed by the IOL.
Abstract:
Asymmetric intraocular lenses (IOLs) are disclosed in which the centration of the optic and the pupil can be adjusted in order to reduce dsyphotopsia and/or the perception of dark shadows. For example, IOLs with uneven haptics are disclosed such that the center of the optic (i.e., the optical axis) is offset from a centerline of the overall device.
Abstract:
In certain embodiments, calculating intraocular lens (IOL) power includes determining locations of parts of an eye along an axis of the eye. The locations include the location of a cornea, the anterior and posterior locations of a crystalline lens, and the location of a retina. An IOL location of an IOL is calculated according to the anterior and posterior locations of the crystalline lens. Corneal data is also determined. The IOL power is calculated using the corneal data, the IOL location, and the retinal location. In certain embodiments, refractive indices are determined for segments of the axis, and at least one location is adjusted according to the refractive indices.
Abstract:
In certain embodiments, calculating intraocular lens (IOL) power includes determining locations of parts of an eye along an axis of the eye. The locations include the location of a cornea, the anterior and posterior locations of a crystalline lens, and the location of a retina. An IOL location of an IOL is calculated according to the anterior and posterior locations of the crystalline lens. Corneal data is also determined. The IOL power is calculated using the corneal data, the IOL location, and the retinal location. In certain embodiments, refractive indices are determined for segments of the axis, and at least one location is adjusted according to the refractive indices.
Abstract:
The present invention generally provides multifocal ophthalmic lenses, e.g., multifocal intraocular lenses, that employ a central refractive region for providing a refractive focusing power and a diffractive region for providing diffractive focusing powers. The refractive focusing power provided by the lens's central region corresponds to a far-focusing power that is substantially equal to one of the diffractive focusing powers while the other diffractive power corresponds to a near-focusing power. The far-focusing power can be enhanced by changes to the phase of the central refractive region and/or changes to the curvature of the central refractive region.
Abstract:
An IOL is disclosed that includes an anterior surface and a posterior surface disposed about an optical axis, where the posterior surface includes a central region extending to a peripheral region. Once the IOL is implanted in a patient's eye, the anterior surface and the central region of the posterior surface cooperatively form an image of a field of view on the retina and the peripheral region of the posterior surface directs at least some light rays incident thereon (e.g., via refraction by the anterior surface) to at least one retinal location offset from the image so as to inhibit dysphotopsia.