37 results about "Cornea thickness" patented technology

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 method of determining a corneal thickness and an apparatus for determining the same. The method comprises the following steps of illuminating a cornea by a plurality of stimulator point light sources, capturing an image of the cornea comprising reflected images of the stimulator point light sources, obtaining a first model representing an anterior surface of the cornea, constructing a second model representing a posterior surface of the cornea from the image by ray-tracing the reflected images of the stimulator point light sources towards the first model representing the anterior surface of the cornea, and determining the corneal thickness from the first model representing the anterior surface and the second model representing the posterior surface.

An improved apparatus and method of intraocular pressure determination is disclosed in which applanation tonometery is done simultaneously with pachymetry. The method allows for increased accuracy of intraocular pressure determination based upon adjustments of applanation tonometry for corneal thickness. The device allows an untrained operator to quickly and easily determine the accurate intraocular pressure.

The invention relates to apparatus and method for measuring Internal Ocular Pressure (IOP) comprises applying a perturbing vibration (2) into an eye (1) over a range of frequencies. A vibrational response of the surface of the eye is measured such as by using a laser velocimeter (6), said response including velocity and rate of change of the phase lag. Further, geometric properties such as volume of the eye are measured such as by using as a laser interferometer (13) to measure characteristics such as the eye's axial length and cornea thickness. Use of multiple characteristics normalize the effect of an eye's mechanical and geometric properties and thereby more accurately determine the IOP.

Embodiments described herein provide improved systems and methods for corneal pachymetry. These systems and methods can be used to improve the accuracy of corneal measurements that are used for a wide variety of different ophthalmic procedures. One embodiment provides a system and method for corneal pachymetry using a plenoptic detector. For example, a corneal pachymetry system can comprise a light source, a plenoptic detector and a processing system coupled to the plenoptic detector. The light source is configured to illuminate the cornea of the eye, and the plenoptic detector is positioned at an angle relative to the eye. The plenoptic detector is configured to receive an image of the light source reflected from the cornea and generate plenoptic image data representing the images. The processing system is coupled to the plenoptic detector and is configured to analyze the plenoptic image data to accurately determine the corneal thickness of the eye.

The invention provides a corneal thickness measuring method based on subdivision of pulses, which belongs to an ultrasonic thickness measuring method. Measurement precision of the corneal thickness measuring method can achieve the micrometer level. Subdivision of pulse is realized by the aid of phase shift of a transmitted pulse, an ultrasonic signal which is reflected back is received, the frontwall and the rear wall of a cornea are judged, a single measurement result is calculated, a next transmitted pulse shifts by a subdivided phase of a pi phase, an ultrasonic signal which is reflected back is received, a current measurement result is obtained, and after total transmitted pulses shift by the pi phase, a last measurement result is obtained. Accurate distances from two sides of the cornea to an ultrasonic sensor are calculated according to the phases corresponding to the maximum values of all the subdivision results, and the final cornea thickness value is obtained by means of subtracting the two accurate distances. If subdivided steps are N, measurement precision is 1 / N of semi-wavelength. The corneal thickness measuring method has the advantages that the ultrasonic thicknessmeasuring method is realized by the aid of subdivision of pulses, the measurement precision can achieve the micrometer level. Resolution ratio of the method is high, center frequency of a probe does not need to be too high, and the corneal thickness measuring method is easy to be popularized.

The invention relates to an intelligent screening system suitable for high myopia complicated by open-angle glaucoma and its establishment method. Based on the repeated testing, adjustment and training of a large number of clinical data of patients with high myopia, the system learns to identify and evaluate optic disc morphology, retinal nerve fiber layer thickness in each quadrant, macular ganglion cell complex thickness from glaucoma OCT examination, and evaluate visual field in visual field examination. For the degree of defect, the degree of optic disc tilt, rotation and β-zone atrophy can be identified and evaluated in fundus images, and then the basic information of the patient, intraocular pressure, spherical power, corneal thickness, eye axis and other indicators can be combined to form a comprehensive screening result. Clinicians provide relevant clinical data to the system of the present invention, and the system of the present invention can quickly and accurately screen out patients with high myopia complicated by open-angle glaucoma or give a risk assessment, providing doctors with early detection and early prevention of high myopia complicated by open-angle glaucoma Glaucoma provides evidence.

The present invention discloses a device for use in ophthalmology, in particular for refractive laser surgery, which aligns a desired ablation profile with predetermined corneal points and takes into account the depth of the anterior chamber of the eye, measured individually for each patient (including corneal thickness) The predetermined corneal point is calculated from the image data of the eye tracker.

The invention provides a method for calculating the diopter of an artificial lens, which is used to solve the problem of large errors in the calculation formula of the IOL diopter in the prior art. The intraocular lens diopter calculation method includes calculating the corneal refractive index through the tangential curvature of the anterior surface of the cornea, calculating the refractive index of the medium in the anterior chamber through the tangential curvature of the posterior surface of the cornea, and calculating , intraocular lens parameters, reserved diopter and the refractive index of each refractive medium of the whole eye to calculate the diopter of the intraocular lens. The present invention introduces the tangential curvature of the anterior surface of the cornea and the tangential curvature of the posterior surface of the cornea into the calculation, utilizes the depth of the anterior chamber, the thickness of the crystal, the ratio of the intrinsic shape of the anterior and posterior capsule of the lens, and the A constant of the artificial lens to accurately estimate the effective lens position, and Systematic calculation is carried out based on the refractive index and location of each refractive medium of the whole eye, which effectively improves the calculation accuracy of the diopter of the intraocular lens, and has a statistical difference.

A method of determining a corneal thickness and an apparatus for determining said is provided. The method comprises the following the steps: —illuminating a cornea by a plurality of stimulator point light sources, capturing an image of the cornea comprising reflected images of the stimulator point light sources, obtaining a model representing an anterior surface of the cornea, —constructing a second model representing a posterior surface of the cornea from the image by ray-tracing the reflected images of the stimulator point light sources towards the model representing the anterior surface of the cornea, determining the corneal thickness from the model representing the anterior surface and the second model representing the posterior surface.