System and method for ophthalmic surface measurements based on objective quality estimation
First Claim
1. A method of evaluating a topography of a corneal surface of an eye of a patient, the method comprising:
- measuring a topography elevation field for the patient eye corneal surface;
determining a measured Zernike amplitude profile for the patient eye based on the topography elevation field;
combining the measured Zernike amplitude profile with a priori corneal surface information to provide an estimated Zernike amplitude profile and an estimated Zernike amplitude covariance matrix for the patient eye, the a priori corneal surface information comprising mean and covariance Zernike amplitude profiles associated with multiple corneal surfaces of a general population;
constructing a corneal topography map for the patient based on the estimated Zernike amplitude profile;
constructing a corneal topography uncertainty map for the patient based on the estimated Zernike covariance matrix; and
evaluating the patient corneal surface topography based on the corneal topography map and the corneal uncertainty map.
1 Assignment
0 Petitions
Accused Products
Abstract
Systems and methods for measuring a topography of an optical tissue surface of an eye are provided by combining a measured elevation of the surface with a priori information of the surface to provide an estimate of mean and covariance of post-measurement orthogonal polynomial sequence amplitudes associated with the surface, determining a variance of elevation of the surface from the estimate, and constructing the topography from the estimate of mean and covariance of post-measurement amplitudes based on a comparison of the variance of elevation of the surface with a pre-determined threshold. The a priori information includes an estimate of mean and covariance of pre-measurement orthogonal polynomial sequence amplitudes associated with the surface.
6 Citations
12 Claims
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1. A method of evaluating a topography of a corneal surface of an eye of a patient, the method comprising:
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measuring a topography elevation field for the patient eye corneal surface; determining a measured Zernike amplitude profile for the patient eye based on the topography elevation field; combining the measured Zernike amplitude profile with a priori corneal surface information to provide an estimated Zernike amplitude profile and an estimated Zernike amplitude covariance matrix for the patient eye, the a priori corneal surface information comprising mean and covariance Zernike amplitude profiles associated with multiple corneal surfaces of a general population; constructing a corneal topography map for the patient based on the estimated Zernike amplitude profile; constructing a corneal topography uncertainty map for the patient based on the estimated Zernike covariance matrix; and evaluating the patient corneal surface topography based on the corneal topography map and the corneal uncertainty map. - View Dependent Claims (2, 3, 4, 5)
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6. A method of planning a refractive correction treatment for an eye of a patient, the method comprising:
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obtaining a measured Zernike amplitude profile for the patient eye, the measured Zernike amplitude profile based on a measured topography elevation field for a corneal surface of the patient eye; combining the measured Zernike amplitude profile with a priori corneal surface information to provide an estimated Zernike amplitude profile and an estimated Zernike amplitude covariance matrix for the patient eye, the a priori corneal surface information comprising a mean and covariance Zernike amplitude profiles associated with multiple corneal surfaces of a general population; constructing a corneal topography uncertainty map for the patient based on the estimated Zernike covariance matrix; constructing a corneal topography map for the patient based on the estimated Zernike amplitude profile and the corneal topography uncertainty map; determining ablation properties locally across the corneal surface of the patient eye based on the corneal topography map; and formulating a treatment plan using the ablation properties by adjusting a first virtual ablation shape to form a second virtual ablation shape, the first virtual shape representing a depth of material to be removed from a treatment area to form a desired shape, the second virtual shape being formed from the first virtual shape in response to the corneal topography map.
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7. A method of treating a cornea of a patient eye with a laser beam, the method comprising:
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obtaining a measured Zernike amplitude profile for the patient eye, the measured Zernike amplitude profile based on a measured topography elevation field for a corneal surface of the patient eye; combining the measured Zernike amplitude profile with a priori corneal surface information to provide an estimated Zernike amplitude profile and an estimated Zernike amplitude covariance matrix for the patient eye, the a priori corneal surface information comprising mean and covariance Zernike amplitude profiles associated with multiple corneal surfaces of a general population; constructing a corneal topography uncertainty map for the patient based on the estimated Zernike covariance matrix; constructing a corneal topography map for the patient based on the estimated Zernike amplitude profile and the corneal topography uncertainty map; mapping angles between the corneal surface and the laser beam over a treatment area; determining ablation properties locally across the treatment area in response to the mapped angles; formulating a treatment plan using the ablation properties by adjusting a first virtual ablation shape to form a second virtual ablation shape, the first virtual shape representing a depth of material to be removed from the treatment area to form a desired shape, the second virtual shape being formed from the first virtual shape in response to the mapped angles; and ablating the treatment area according to the treatment plan to form the desired shape in the corneal surface. - View Dependent Claims (8)
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9. A system for treating a corneal surface of a patient eye with a laser beam, the eye having a refractive defect, wherein a desired refractive correcting shape mitigates the refractive defect, the system comprising:
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a laser emitting a beam of an ablative light energy; and at least one processor coupled to the laser beam and having a computer program, the computer program embodying instructions for; combining a measured Zernike amplitude profile for the patient eye with a priori corneal surface information to provide an estimated Zernike amplitude profile and an estimated Zernike amplitude covariance matrix for the patient eye, the a priori corneal surface information comprising mean and covariance Zernike amplitude profiles associated with multiple corneal surfaces of a general population, and the measured Zernike amplitude profile for the patient eye based on a measured topography elevation field of the patient eye corneal surface; constructing a corneal topography uncertainty map for the patient based on the estimated Zernike covariance matrix; constructing a corneal topography map for the patient based on the estimated Zernike amplitude profile and the corneal topography uncertainty map; determining ablation properties locally across the corneal surface of the patient eye based on the corneal topography map; formulating a treatment plan using the ablation properties by adjusting a first virtual ablation shape to form a second virtual ablation shape, the first virtual shape representing a depth of material to be removed from a treatment area to form a desired shape, the second virtual shape being formed from the first virtual shape in response to the corneal topography map; and controlling an ablative treatment using the treatment plan from the second virtual shape so that the treatment forms the desired refractive correcting shape in the surface.
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10. A method of evaluating an optical tissue of an eye, the method comprising:
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combining a measured orthogonal polynomial amplitude profile for the patient eye with a priori optical tissue information to provide an estimated orthogonal polynomial amplitude profile and an estimated orthogonal polynomial amplitude covariance matrix for the patient eye, the a priori optical tissue information comprising mean and covariance orthogonal polynomial amplitude profiles associated with multiple optical tissue measurements of a general population, and the measured orthogonal polynomial amplitude profile for the patient eye based on a measured topography elevation field of the patient eye corneal surface; constructing an optical tissue uncertainty map for the patient based on the estimated orthogonal polynomial covariance matrix, the uncertainty map representing a measure of measurement quality; and evaluating the optical tissue of the patient eye based on the estimated orthogonal polynomial amplitude profile and the optical tissue uncertainty map. - View Dependent Claims (11)
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12. A method for evaluating the accuracy of an optical tissue measurement of an eye of a patient, the method comprising:
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obtaining amplitude data corresponding to the optical tissue measurement of the patient eye, the amplitude data based on a measured topography elevation field for a corneal surface of the patient eye; obtaining amplitude data and covariance data corresponding to optical tissue measurements of multiple eyes of a population; combining the amplitude data corresponding to the patient measurement with the amplitude data and covariance data corresponding to the population measurements, so as to obtain estimated amplitude data and estimated covariance data; constructing a representation of the patient optical tissue based on the estimated amplitude data; constructing an uncertainty representation of the patient optical tissue based on the estimated covariance data; and evaluating the accuracy of the optical tissue measurement based on the representation of the patient optical tissue and the uncertainty representation of the patient optical tissue.
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Specification