Alcon, Inc.

Martin Gruendig

Peter Zieger

John Alfred Campin

George H Pettit

Sascha Birkner

Daniil Nekrassov

Christopher Sean Mudd

A method of verifying ophthalmic measurements includes obtaining, via an ophthalmic measurement device, a first measurement of at least one ophthalmic parameter over a first measurement area. The first measurement area corresponds to an unassisted visible area of a patient's eye. A second measurement of the at least one ophthalmic parameter over a second measurement area is obtained via the measurement device. The second measurement area corresponds to an assisted visible area of the patient's eye. The first measurement is compared to the second measurement. It is determined if the second measurement diverges from the first measurement. Responsive to a determination that the second measurement diverges from the first measurement, an alert that the second measurement is inaccurate is generated. Responsive to a determination that the second measurement does not diverge from the first measurement, the second measurement is accepted as accurate.

Method and system for measuring optical parameters

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.

Measuring a posterior corneal surface of an eye

Disclosed are systems and methods for aligning an ophthalmic device with respect to an eye of a patient. In one disclosure, the system may include an ophthalmic device with an on-axis and an off-axis. The system may include an on-axis illuminator that emits light that is reflected by the eye of the patient to form an on-axis reflection having a center. The system may include an on-axis camera pointed along the on-axis. The system may include an off-axis illuminator that emits light that is reflected by the eye to form an off-axis reflection having a center. The system may include an off-axis camera pointed along the off-axis. The ophthalmic device may be operable to be aligned with respect to the eye of the patient when the on-axis is substantially normal to the center of the on-axis reflection and the off-axis is substantially normal to the center of the off-axis reflection.

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Rangsdorf, Germany

Martin Gruendig