Controlled rate freezing for cryorefractive surgery
AssigneeUniversity of Southern California
InventorDavid J. Schanzlin
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Abstract
A method for freezing corneal tissue prior to cryorefractive surgery, including the controlled rate freezing of the tissue at a rate of less than seven degrees centigrade per minute.
Claims5
In a method for refractive keratoplasty which includes freezing and latching a corneal portion to modify the surface curvature thereof, the improvement comprising the steps of cooling the corneal portion at a rate of less than about 7.degree. C. per minute over a temperature range below +4.degree. C. to a temperature above -40.degree. C. to freeze the corneal portion, and lathing the surface of the frozen corneal portion to a predetermined curvature.
A method for performing cryorefractive surgery on the cornea of a patient, comprising:
- obtaining a corneal portion;
- cooling the corneal portion, over a temperature range of below 4.degree. C., at a rate of less than 7.degree. C. per minute until the corneal portion is frozen;
- lathing the surface of the frozen corneal portion to a predetermined curvature;
- thawing the lathed corneal portion to about room temperature;
- and
- grafting the lathed corneal portion to the cornea of the patient.
Dependencies are inferred from the claim text.