77 results about "Corneal topographer" patented technology

A method for the simultaneous measurement of the anterior and posterior corneal surfaces, corneal thickness, and optical aberrations of the eye. The method employs direct measurements and ray tracing to provide a wide range of measurements for use by the ophthalmic community.

A system measures a corneal topography of an eye. The system includes a group of first light sources arranged around a central axis, the group being separated from the axis by a radial distance defining an aperture in the group; a plurality of second light sources; a detector array; and an optical system adapted to provide light from the second light sources through the aperture to a cornea of an eye, and to provide images of the first light sources and images of the second light sources from the cornea, through the aperture, to the detector array. The optical system includes an optical element having a focal length, f. The second light sources are disposed to be in an optical path approximately one focal length, f, away from the optical element.

An optical measurement system and apparatus for carrying out cataract diagnostics in an eye of a patient includes a Corneal Topography Subsystem, a wavefront aberrometer subsystem, and an eye structure imaging subsystem, wherein the subsystems have a shared optical axis, and each subsystem is operatively coupled to the others via a controller. The eye structure imaging subsystem is preferably a fourierdomain optical coherence tomographer, and more preferably, a swept source OCT.

Methods, software, and systems are provided for determining an ablation target shape for a treatment for an eye of a patient. Techniques include determining wavefront information from the eye of the patient with a wavefront eye refractometer, determining anterior corneal shape information from the eye with a corneal topography device, and combining the wavefront information and the anterior corneal shape information to determine the ablation target shape.

A corneal topography analysis system includes: an input unit for inputting corneal curvature data; and an analysis unit that determines plural indexes characterizing topography of the cornea based on the input corneal curvature data, the analysis unit further judges corneal topography from features inherent in predetermined classifications of corneal topography using the determined indexes and a neural network so as to judge at least one of normal cornea, myopic refractive surgery, hyperopic refractive surgery, corneal astigmatism, penetrating keratoplasty, keratoconus, keratoconus suspect, pellucid marginal degeneration, or other classification of corneal topography.

A method and apparatus for the simultaneous measurement of the anterior and posterior corneal surfaces, corneal thickness, and optical aberrations of the eye. The method employs direct measurements and ray tracing to provide a wide range of measurements for use by the ophthalmic community.

A visual optical analysis system based on a wave-front aberration is provided, which belongs to the technology field of medical optics. In the invention, a first light splitter is positioned between a light diaphragm and a cornea, the emergent light from a Placideo's disk passes through a second light splitter and a third light splitter and then is projected onto the surface of the cornea, the emergent light from the cornea is reflected by a fourth light splitter to a corneal topography imaging system, the corneal topography imaging system is positioned between a first aperture-matching system and a monitoring CCD, an astigmatism compensation system is positioned between the first aperture-matching system and a beam-splitting prism, a part of the emergent light reflex from the beam-splitting prism passes through a second aperture-matching system and then one part thereof reaches an object and the other part radiates to a Shack-Hartmann wave-front sensor, the emergent light from the beam-splitting prism is partially transferred to a deformable mirror, an imaging objective lens is provided between a fifth light splitter and the object, and the Shack-Hartmann wave-front sensor and the deformable mirror are respectively connected with a computer. The visual optical analysis system realizes the data acquisition of human eye aberration and corneal topography, as well as correction of the human eye aberration.

An apparatus for enabling corneal topography includes an attachment to align a placido disc illumination system with a camera of a mobile communication device. The placido disc illumination system generates concentric rings and reflects the concentric rings off a cornea. A portion of the reflected concentric rings are utilized to confirm vertex distance. The apparatus further comprises a memory, a processor, and computer-readable instructions in a mobile communication device. The camera captures an image of reflected concentric rings and communicates the captured image of the reflected concentric rings to an external computing device. A method for performing corneal topography utilizes a mobile computing and / or communication device, projects a plurality of peripheral concentric rings onto a subject's cornea and projects center rings onto the subject's cornea. The method further includes capturing, via a smartphone camera, an image of the projected peripheral concentric rings and the center rings.

The invention provides a design method for a cornea contact lens based on a wave front technology. The method is a technology for obtaining a surface type structure of the cornea contact lens according to an objective measurement data of eye vision light; according to actually measured corneal topography data, optimum spherical or circular fitting is processed for the cornea front surface by MATLAB software programming to design the surface type structure of an optical region on the back surface of the cornea contact lens. The spreading of the wave front that is transmitted to the cornea front surface from the exit pupil plane through a tear lens and a cornea contact lens medium is calculated according to the actually measured wave front aberration data of human eyes based on a diffractive angular spectrum theory so as to obtain the equivalent wave front aberration of the front surface of the cornea contact lens and then fit to figure out the optimum curved surface type of the optical region on the front surface of the cornea contact lens for correcting the wave front aberration of eye; and the optimum sphericity, column degree and parallactic angle of an astigmatism axis of the cornea contact lens are figured out for the cornea contact lens by calculating and fitting the designed surface type structures for optical region on the front and back surfaces of the cornea contact lens.

Embodiments of the invention are generally directed to apparatus and methods for measuring a deformation characteristic of a deformable target surface. The measurement principles of the invention may be applied to a large variety of organic (e.g., human, animal or plant tissue) and inorganic materials having a surface that can be deformed by an applied non-contact force. The surface may be light diffusing and non-transparent or non-diffusing and transparent. An illustrative embodiment of the invention is directed to a device for measuring a deformation characteristic of a cornea. The device comprises a corneal topographer and a non-contact tonometer that is operationally integrated with the corneal topographer. In an aspect, the corneal topographer is a rasterstereography-based topographer. Use of the inventive device enables a method for measuring a deformation characteristic of the cornea. In addition to the measurable deformation characteristics listed above, dioptric power, intraocular pressure, corneal hysteresis, corneal elasticity, corneal viscosity and various known corneal topography characteristics can be measured.

The invention provides a corneal topography measuring apparatus which can precisely measure curved transition of radial direction and tangential direction of cornea and comprises a Hartmann sensor, a focusing object lens and matching optical paths such as a light source, expanding beam, contracting beam, monitoring and controlling of point spread functions, pupilla imaging, an object, etc. The reflected light on the outer surface of the cornea is gathered by the Hartmann wave front sensor that is conjugated with cornea face after being propagated through an optical system, wave front aberration is obtained after wave front treatment and then a corneal topography is obtained. The matching paths finish auxiliary work of object alignment, object fixation, etc. The corneal topography measuring apparatus of the invention can not only measure information of the surface of the cornea in a large area but also have higher resolving power and measurement accuracy.

Selecting an optimal intraocular lens (IOL) from a plurality of IOLs for implanting in a subject eye, including measuring anterior corneal topography (ACT), axial length (AXL), and anterior chamber depth (ACD) of a subject eye; selecting a default equivalent refractive index depending on preoperative patient's stage or calculating a personalized value or introducing a complete topographic representation if posterior corneal data are available; creating a customized model of the subject eye with each of a plurality of identified intraocular lenses (IOL) implanted, performing a ray tracing through that model eye; calculating from the ray tracing a RpMTF or RMTF value; and selecting the IOL corresponding to the highest RpMTF or RMTF value for implanting in the subject eye.

The invention discloses image acquisition equipment applied to a corneal topography instrument. The image acquisition equipment comprises an equipment shell, an image acquisition system and a three-dimensional moving platform, wherein the equipment shell is provided with a light pass hole; the image acquisition system is positioned in the equipment shell; the three-dimensional moving platform is used for arranging the image acquisition system; the image acquisition system comprises a CCD (Charge Coupled Device) imaging system with a CCD camera, a lens system and an optical projection device; the three-dimensional moving platform is driven through a step motor; and both the step motor and the CCD camera are controlled by an upper computer with an image display device. An optimal position between the image acquisition system and a human eye cornea can be adjusted through an image acquisition software widow of the upper computer. The image acquisition equipment can be used for precisely adjusting the relative position between the image acquisition system and the human eye cornea in place of a hand, and an image of the human eye cornea can be acquired by applying an overlook type positioning and acquisition method in place of the conventional front positioning and acquisition method, so that the image acquisition equipment is easy and convenient to operate and high in accuracy.

The invention discloses an ocular anterior segment detection and illumination system, comprising a light source as well as a light condensing mirror, a R, G and B (red, green and blue) three-color liquid crystal sheet unit or a digital light processor (DLP), a lower projecting mirror group and a reflecting mirror, which are sequentially distributed in an emerging direction of light rays of a light source, wherein the light condensing mirror and the lower projecting mirror group are coaxially arranged, and a liquid crystal sheet or a digital micromirror unit is connected with a control unit. The control unit comprises a computer system, preferentially, the computer system is also connected with at least one control device of a game control rod, a mouse and a keyboard. The ocular anterior segment illumination system is simple in structure, easy to control, has high stable property and high image quality and can achieve new functions for data measurement such as measurement of corneal topography, corneal curvature and the like.

A corneal topographer includes: a flat panel display configured to display a light pattern and to project the light pattern onto a cornea of an eye disposed on a first side of the flat panel display; an optical system disposed on a second side of the flat panel display, the optical system being configured to receive and process reflected light from the cornea that passes through the flat panel display from the cornea to the optical system; a camera configured to receive the processed reflected light from the optical system and to capture therefrom a reflected light pattern from the cornea produced in response to the projected light pattern; and one or more processors configured to execute an algorithm to compare the projected light pattern to the reflected light pattern from the cornea, and to produce a topographic map of the cornea based on a result of the comparison.

Methods, software, and systems are provided for determining an ablation target shape for a treatment for an eye of a patient. Techniques include determining wavefront information from the eye of the patient with a wavefront eye refractometer, determining anterior corneal shape information from the eye with a corneal topography device, and combining the wavefront information and the anterior corneal shape information to determine the ablation target shape.

An advanced rasterstereography-based corneo-scleral topography (RCT) device includes an LED-based grid projection assembly, a grid image viewing assembly, and an optionally integratable front view camera assembly. The assemblies each include telephoto optical systems that provide a compact structure, an increased depth of field, and an increased field of view that allow sufficient acquisition of data in a single acquired image to provide the desired corneo-scleral topography analysis. The device utilizes a novel image processing algorithm. The device and method provide the capability to map a feature from a raw grid image onto a topography map of the corneo-scleral region, and to simultaneously display the images if selected by the user. The hardware, software, mechanical, electrical, and optical design considerations and integration provide advantages and benefits over prior RCT-type, Placido-based, and other conventional corneal topographers.

A placido projector for a corneal topography system includes a substrate having dielectric phosphor. The substrate is configured to be activated by electric current and responsive to emit light. A plurality of opaque, concentric rings are formed on the substrate. When the substrate emits light responsive to the electric current, a placido image is projected. The concentric rings can be formed using silk screening or other techniques. The dielectric phosphor can be micro-encapsulated and deposited onto the substrate. The substrate may be an electro-luminance panel. A protective cover is placed adjacent to the substrate to retain the substrate in a predetermined shape. In one embodiment, the placido projector has a frusto conical shape.

Selecting an optimal intraocular lens (IOL) from a plurality of IOLs for implanting in a subject eye, including measuring anterior corneal topography (ACT), axial length (AXL), and anterior chamber depth (ACD) of a subject eye; selecting a default equivalent refractive index depending on preoperative patient's stage or calculating a personalized value or introducing a complete topographic representation if posterior corneal data are available; creating a customized model of the subject eye with each of a plurality of identified intraocular lenses (IOL) implanted, performing a ray tracing through that model eye; calculating from the ray tracing a RpMTF or RMTF value; and selecting the IOL corresponding to the highest RpMTF or RMTF value for implanting in the subject eye.

A method to encode both high-resolution and low-resolution reflected features of a cornea to improve the measurements for reflection based corneal topography systems. The corneal topography reflective target provides for multiple resolutions of measurements to be obtained from a single acquisition.

A Method of evaluating a correspondence between a target surface and a reconstructed surface representing the target surface is described. The reconstructed surface can be constructed by processing information obtained by illuminating the target surface with a pattern of light of a stimulator source, and capturing a reflected image of the pattern of light on an image target, the method further comprising the steps of—Determine a reference image point on the image target corresponding to a reference stimulator point on the stimulator source,—Calculating for the reference image point, using the reconstructed surface, a residual representing the correspondence between the target surface and the reconstructed surface.—Displaying the residual together with the reflected image.

A laser eye surgery system includes a laser to generate a laser beam. A topography measurement system measures corneal topography. A processor is coupled to the laser and the topography measurement system, the processor embodying instructions to measure a first corneal topography of the eye. A first curvature of the cornea is determined. A target curvature of the cornea that treats the eye is determined. A first set of incisions and a set of partial incisions in the cornea smaller than the first set of incisions are determined. The set of partial incisions is incised on the cornea by the laser beam. A second corneal topography is measured. A second curvature of the cornea is determined. The second curvature is determined to differ from the target curvature and a second set of incisions are determined. The second set of incisions is incised on the cornea.

The invention relates to a handheld acquisition system for recording cornea information. The handheld acquisition system comprises a projection part (101), a camera lens (103), a camera (104) and an image analysis system (105), wherein the projection part (101) consists of LED backlight sources (111) and a Placido disk; the inner surface of the Placido disk adopts concentric circular rings which are uniformly chequered with black and white; and light rays emitted by the LED backlight sources (111) are blocked by black parts in the rings and penetrate through the white part in the rings to be transmitted to a cornea (112) to be tested, the inner part of the Placido disk adopts a rotational symmetry discretionary face type, the opening part facing the cornea (112) to be tested, of the Placido disk is extended as far as possible to be convenient for processing of the inner part of the Placido disk, and the rays reflected from the cornea (112) to be tested are imaged through the camera lens (104). The acquisition system is adopted, so that good view fields and image quality can be obtained, and shape changing rule of the shape of the cornea can be conveniently obtained.

A method and a device for evaluating the fitness of a corneal shaping lens are provided in the embodiments of the present invention, According to the refraction of each sampling point obtained from the corneal topography, the edge data points in each radial direction of the treatment area of the keratoplasty lens can be screened, the treatment area can be fitted according to the edge data points,and the fit state of the keratoplasty lens can be evaluated according to the eccentric distance. In this way, according to each data obtained from the corneal topography map, the analysis data of thefitness state of the corneal shaping lens can be obtained, the fitness state of the corneal shaping lens can be evaluated, and the evaluation error can be reduced by analyzing the specific data.