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US 6,142,989 AGranted
Apparatus and method for customized laser correction of refractive error
OwnerFrancis E. O'Donnell, Jr.inventor
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Abstract
Improved methods of spherical and astigmatic laser correction. By using an array of micro-charge coupled devices, a spatially-resolved refractive error map is generated which guides the treatment process. Improved astigmatic correction is provided by avoiding laser treatment of the unaffected cornea. Complex astigmatic corrections including lenticular astigmatism and mixed astigmatism are treated by first sphericizing the corneal surface before correcting the residual refractive error.
Claims8
A method of performing laser surgery to correct astigmatism without developing an unwanted coupling effect comprising:
- determining a point-to-point corneal astigmatic refractive error;
- determining a visual axis;
- determining a treatment zone adjacent the visual axis based upon the point-to-point corneal astigmatic refractive error and the visual axis;
- ablating the treatment zone while sparing said visual axis by ablating the treatment zone in a pie-shaped segment limited to an approximately 45.degree. to approximately 60.degree. arc of the pine-shaped segment on either side of the visual axis;
- and
- ablating said treatment zone in a graduated manner.
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Dependencies are inferred from the claim text.