Method and apparatus for analysis and correction of abnormal refractive errors of the eye
First Claim
1. The method of using a digital computer to correctively improve optical properties of an eye by changing the curvature of the anterior surface of the cornea in approach to a computer-stored digital definition of an idealized three-dimensional anterior-surface curvature, which method comprises:
- (a) determining and digitizing the topography of the anterior surface of the cornea as a three-dimensional curved surface, and entering digitized topography data thereof into computer storage;
(b) creating from said topography data and from said stored digital definition a displayed numerical statement of the spherical and cylindrical-components of difference bewteen the determined and the idealized curvatures, whereby the displayed numerical statement is also a statement which is definitive of a characterized volumetric removal of corneal tissue necessary to proceed from the determined to the idealized curvature;
(c) directing ultraviolet laser radiation to the anterior surface of the cornea to selectively ablate the same by photodecomposition; and
(d) using said computer-storage data to control the laser radiation to achieve a curvature change in approach to the diealized surface curvature in a volumetric removal of tissue from the anterior surface and with penetration into the stroma.
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Accused Products
Abstract
The invention contemplates instrumentation to aid in performing refraction-corrective surgery on the conrea, (1) by determining the topography of the anterior surface of the cornea, the determination being in the form of digitized data entered into computer storage, (2) by determining the local thickness of the cornea along multiple axes, the determination being also in the form of digitized data entered into computer storage, and (3) by providing a CAD/CAM display of both categories of data, correlated as appropriate for the surgeon'"'"'s selective display of a corneal region, aspect or section, as the surgeon may deem pertinent to a prospective operation.
546 Citations
13 Claims
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1. The method of using a digital computer to correctively improve optical properties of an eye by changing the curvature of the anterior surface of the cornea in approach to a computer-stored digital definition of an idealized three-dimensional anterior-surface curvature, which method comprises:
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(a) determining and digitizing the topography of the anterior surface of the cornea as a three-dimensional curved surface, and entering digitized topography data thereof into computer storage; (b) creating from said topography data and from said stored digital definition a displayed numerical statement of the spherical and cylindrical-components of difference bewteen the determined and the idealized curvatures, whereby the displayed numerical statement is also a statement which is definitive of a characterized volumetric removal of corneal tissue necessary to proceed from the determined to the idealized curvature; (c) directing ultraviolet laser radiation to the anterior surface of the cornea to selectively ablate the same by photodecomposition; and (d) using said computer-storage data to control the laser radiation to achieve a curvature change in approach to the diealized surface curvature in a volumetric removal of tissue from the anterior surface and with penetration into the stroma. - View Dependent Claims (2, 3, 4)
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5. The method of using a digital computer to correctively improve optical properties of an eye by changing the curvature of the anterior surface of the cornea, which method comprises:
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(a) determining and digitizing the topography of the anterior surface of the cornea as a three-dimensional curved surface, and entering digitized topography data thereof into computer storage; (b) entering into computer storage, as another three-dimensional curved surface, digitized data for the anterior-surface topography of an idealized cornea wherein optical improvement is the achievement objective based on measured parameter data for the eye, whereby computer storage contains digitized data which is definitive of a characterized volumetric removal necessary to proceed from one to the other of said curved surfaces; (c) directing ultraviolet laser radiation to the anterior surface of the cornea to selectively ablate the same by photodecomposition; and (d) using said computer-storage data to control the laser radiation to achieve said other curved surface in a volumetric removal of tissue from the anterior surface and with penetration into the stroma. - View Dependent Claims (6, 7, 8, 9)
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10. The method of using a digital computer to correctively improve optical properties of an eye by changing the curvature of the anterior surface of the cornea, which method comprises:
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(a) measuring and digitizing the topography of the anterior surface of the cornea as a three-dimensional curved surface, and entering digitized topography data thereof into computer storage; (b) creating from the stored digitized topography data a center-identified display of the front elevation of the cornea; (c) creating on said display a straight marker line along a meridian through the center of the display and at a slected orientation; (d) entering into computer storage digitized data for the corneal topography of an idealized eye wherein emmetropia is the achievement objective; (e) creating from the stored digitized data for the measured eye and for the idealized eye a coordinated display of both curvature along said meridian, whereby computer storage contains digitized data which is definitive and said coordinated display is visually indicative of a characterized volumetric removal of corneal tissue necessary to proceed from the measured curvature toward the idealized curvature; (f) directing ultraviolet laser radiation to the anterior surface of the cornea to selectively ablate the same by photodecomposition; and (g) using said computer-storage data to control the laser radiation to approach the idealized curvature in a volumetric removal of tissue from the anterior surface and with penetration into the stroma. - View Dependent Claims (11, 12, 13)
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Specification