Alcon, Inc.

Daniil Nekrassov

Martin Gründig

John Alfred Campin

George H Pettit

Peter Zieger

Horia Grecu

Mark Andrew Zielke

Martin Gruendig

In certain embodiments, an ophthalmic system for assessing a tear film of an eye comprises measuring devices and a computer. The measuring devices detect light reflected from the eye, where an ocular surface of the eye comprises the tear film, and generate data from the reflected light that describes the eye. The computer aligns the data corresponding to the same location for a plurality of locations, assesses the data at the locations to detect one or more abnormalities of the tear film, and determines a tear film description from the assessment of the data at the locations.

Multi-detector analysis of the tear film of an eye

An ophthalmic system for generating a topography of an anterior corneal surface of an eye comprises an illuminator, cameras, and a computer. The illuminator illuminates the anterior corneal surface of the eye with a Placido pattern, which reflects the Placido pattern. Each camera generates an image of the reflected Placido pattern to yield multiple images. At least one camera is oriented off an axis of the eye. For each image, the computer calculates a curvature value for each data point of the image, where a data point corresponds to a surface point of the anterior corneal surface. The calculations yield curvature values for each surface point. The computer determines the curvature at each surface point from one or more curvature values for the surface point. The computer generates the topography of the anterior corneal surface from the curvatures at the surface points of the anterior corneal surface.

Multi-view corneal topographer

An ophthalmic system for measuring an eye comprises measuring devices and a computer. The measuring devices comprise an optical coherence tomography (OCT) device and an aberrometer. The OCT device directs OCT light towards the eye, and detects the OCT light reflected from the eye to measure the eye. The aberrometer directs aberrometer light towards the eye, and detects the aberrometer light reflected from the eye to measure the eye. The computer generates an ocular model of the eye according to the reflected OCT light. The ocular model comprises parameters for the eye, where each parameter is assigned a value. The computer determines an OCT-based wavefront according to the ocular model, determines an aberrometer-based wavefront according to the reflected aberrometer light, ascertains a deviation between the OCT-based wavefront and the aberrometer-based wavefront, and evaluates measurements from one or more of the measuring devices according to the deviation.

Evaluating measurements using information from multiple measuring devices

An ophthalmic system for generating an ocular model of an eye includes an optical coherence tomography (OCT) device, an aberrometer, and a computer. The OCT device detects OCT light reflected from the eye. The aberrometer detects aberrometer light reflected from the eye. The computer generates the ocular model of the eye according to the reflected OCT light. The ocular model includes parameters describing the eye. The parameters include lens parameters that describe the lens of the eye. The computer determines an OCT-based wavefront according to the ocular model, determines an aberrometer-based wavefront according to the reflected aberrometer light, and compares the OCT-based and the aberrometer-based wavefronts. If the wavefronts differ beyond a predefined tolerance, the computer adjusts one or more values assigned to the parameters until the wavefronts satisfy the predefined tolerance. At least one adjusted value is assigned to a lens parameter.

Refining lens parameters of an ocular model

In certain embodiments, a system for measuring the posterior corneal surface of the cornea comprises cameras and a computer. Each camera generates image data representing a part of the eye posterior to the cornea. The image data describes locations of features of the part. The computer stores a description of the shape of an anterior corneal surface of the cornea, and applies a ray-tracing process to determine the shape of the posterior corneal surface. The ray-tracing process comprises defining rays, where each ray is traced from a camera, through the anterior and posterior corneal surfaces, and to the part of the eye. Constraints for the rays are determined, where the constraints are calculated using the description of the shape of the anterior corneal surface and locations of the features in the image data. Parameters are optimized, and the optimized parameters describe the shape of the posterior corneal surface.

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Berlin, Germany

Daniil Nekrassov