System and method for measuring tilt
A method of generating three dimensional shapes for a cornea and lens of an eye, the method including illuminating an eye with multiple sections of light and obtaining multiple sectional images of said eye based on said multiple sections of light. For each one of the obtained multiple sectional images, the following processes are performed: a) automatically identifying arcs, in two-dimensional space, corresponding to anterior and posterior corneal and lens surfaces of the eye by image analysis and curve fitting of the one of the obtained multiple sectional images; and b) determining an intersection of lines ray traced back from the identified arcs in two-dimensional space with a known position of a section of space containing the section of light that generated the one of the obtained multiple sectional images, wherein the determined intersection defines a three-dimensional arc curve. The method further including reconstructing three-dimensional shapes of the anterior and posterior cornea surfaces and the anterior and posterior lens surfaces based on fitting the three-dimensional arc curve to a three-dimensional shape.
1 . A laser system for cutting an eye, the system comprising:
a biometric system;
the biometric system configured for generating three dimensional shapes for a cornea and lens of an eye, the biometric system comprising:
(a) an illumination source configured to direct multiple sections of light to an eye;
(b) a camera, configured to receive multiple sectional images of the eye generated by the multiple sections of light;
(c) an image processor system in communication with the camera; and,
(d) the image process system configured to perform the following processes on an obtained sectional image:
(i) identifying arcs, in two-dimensional space, corresponding to anterior and posterior corneal and lens surfaces of the eye from the obtained sectional image by image analysis and curve fitting of the obtained sectional image;
(ii) determining an intersection of lines ray traced back from the identified arcs in two-dimensional space from one of the obtained multiple sectional images to an intersection of the lines with a known position of a section of space containing the section of light that generated the one of the obtained multiple sectional images, wherein the determined intersection defines a three-dimensional arc curve; and
(iii) determining coordinates of arcs of the one of the multiple sectional images based on the one of the multiple sectional images and the determining an intersection of lines; and
(iv) reconstructing three-dimensional shapes of the anterior and posterior cornea surfaces and the anterior and posterior lens surfaces based on fitting the three-dimensional arc curve to a three-dimensional shape;
wherein the laser system is configured to form a cut in the eye based at least in part on the reconstructed three-dimensional shape of the lens.
2 . The system of claim 1 , wherein the laser system is configured to form a cut in the eye based at least in part on the reconstructed three-dimensional shape of the cornea.
3 . The system of claim 1 or 2 , wherein the cut comprises a capsulotomy.
4 . The system of claim 1 , wherein the cut comprises a capsulotomy and wherein the system is configured to center the capsulotomy based at least in part on the reconstructed three-dimensional shape of the lens.
5 . The system of claim 2 , wherein the system is configured to center the capsulotomy based at least in part on the reconstructed three-dimensional shape of the lens and the cornea.
6 . The system of claim 1 , wherein the cut comprises a capsulotomy and wherein the system is configured to center the capsulotomy, wherein the centering comprises:
(a) finding three-dimensional models for determining centers of curvature for at least two of the anterior and posterior cornea and lens surfaces;
(b) calculating a line from coordinates of the determined centers of curvature; determining a point where the line intersects the anterior cornea surface; and centering an IOL on the capsulotomy based on the determined point.
7 . The system of claim 6 , wherein the three dimensional models are spherical three dimensional models.
8 . The system of claim 6 , wherein the three dimensional models are three dimensional surfaces based on Zernike polynomials or their equivalent.
9 . The system of claim 1 or 2 , wherein the section of light is a longitudinal sheet of light.
10 . The system of claim 1 or 2 , wherein at least one of the sections of light is non-planar.
11 . The system of claim 1 , wherein at least one of the sections of light is cylindrical.
12 . The system of claim 1 , wherein at least one of the sections of light is generated by a spiral scan.