METHOD AND APPARATUS FOR DETERMINING EYE TOPOLOGY
A method and apparatus for measuring the topography of the corneal and scleral regions of the eye. The measurements provide surface contours that are useful in the manufacture of scleral contact lenses.
1 . An apparatus comprising
a light source for generating an optical beam;
a scanner for scanning the optical beam to impinge a surface of an eye along a plurality of meridian scan lines of the eye;
detecting detector, for detecting at a plurality of positions located along each meridian scan line, a reflected optical energy component to thereby determine a set of distances for each meridian scan line;
a camera, for capturing, at the same time as the detecting for each meridian scan line, a two dimensional visual image of the eye associated with the respective meridian scan line, to the camera thus producing a set of two-dimensional images having a two-dimensional image for each meridian scan line; and
an image processor, for aligning the set of two-dimensional images to generate a composite three-dimensional image of the eye, and to thereby also obtain a three-dimensional topography of the eye, and to thereby compensate the three-dimensional is image and the three-dimensional topography for eye motion.
2 . The apparatus of claim 1 wherein the scanner additionally scans the optical beam along an axis that includes a line normal to a line tangent to a point on a sclera and to a point on a cornea of the eye.
3 . The apparatus of claim 2 additionally comprising:
a platform for supporting the scanner and camera, the platform rotatable about an axis that is perpendicular to an optical axis of the eye.
4 . An apparatus as recited in claim 2 wherein the tangent line forms an angle between 27 degrees and 47 degrees relative to an axis perpendicular to a top of a pupil of the eye.
5 . The apparatus of claim 1 additionally comprising:
means for fabricating a lens from the three dimensional topography of the eye.
6 . The apparatus of claim 1 additionally comprising:
a support member for directing a patient to stare at a point of fixation while the patient angularly rotates their head to a different head position for each of a plurality of scanning steps.
7 . The apparatus of claim 6 wherein the image processor is additionally for stitching two-dimensional images obtained for two or more head positions.
8 . The apparatus of claim 1 wherein the scanner further comprises an optical coherence tomography scanner.
9 . The apparatus of claim 1 wherein the scanner further directs illumination across a portion of the eye using the light source and a scanning mirror.
10 . The apparatus of claim 1 wherein the composite three dimensional image includes at least one of the cornea, iris, pupil, shape of the pupil, sclera, or blood vessels in the sclera.