Patent NZ-583375-A (NZ)
Title: System and method for defining and controlling ltk and other surgical eye procedures to produce little or no stromal collagen shrinkage
Inventor: BERRY MICHAEL J
IPC: A61F9/008
Filed: 2008-08-19
Abstract: 583375 An apparatus for defining and controlling laser thermal keratoplasty (LTK) and other surgical eye procedures to produce little or no stromal collagen shrinkage is disclosed. Also disclosed is a method of designing a cornea reshaping procedure. The apparatus (116) comprises a memory configured to store at least one model and a processor. The at least one model is associated with a cornea reshaping procedure that comprises irradiating multiple spots on a cornea of a patient's eye through a heat sink so that depressions form at the spots and change a shape of the cornea. The heat sink comprises a window configured to contact at least a portion of the cornea of the patient's eye. The window is configured to cool at least a portion of a corneal epithelium in the cornea during the cornea reshaping procedure. Each spot associated with an amount of stromal collagen. The processor is configured to determine one or more treatment parameters for the cornea reshaping procedure using the at least one model. The one or more treatment parameters comprise one or more of: an irradiation wavelength, an irradiation power, a spot size, and a duration of irradiation. The processor is configured to determine the one or more treatment parameters in order to at least partially achieve a desired shape change to the cornea of the patient's eye while minimizing an amount of stromal collagen shrinkage in the cornea of the patient's eye so that no more than 5% of the stromal collagen in the irradiated spots undergoes clinically significant shrinkage as a result of the cornea reshaping procedure. The heat sink is configured to prevent a corneal wound healing response from being triggered as a result of the cornea reshaping procedure and the processor is configured to determine the one or more treatment parameters so as to prevent permanent opacifications from forming in the cornea of the patient's eye. A system (100) is also disclosed comprising a radiation source, a heat sink configured to be attached to the patient's eye and a controller configured to control the delivery of the radiation to the patient's eye in accordance with one or more treatment parameters. The radiation source is configured to generate radiation for a cornea reshaping procedure that comprises irradiating multiple spots on a cornea of a patient's eye, each spot associated with an amount of stromal collagen. The heat sink comprises a window configured to contact at least a portion of the cornea, the window substantially transparent to the radiation. The window is also configured to cool at least a portion of a corneal epithelium in the cornea during the cornea reshaping procedure. The one or more treatment parameters are selected in order to at least partially achieve a desired shape change to the cornea of the patient's eye while minimizing an amount of stromal collagen shrinkage in the cornea of the patient's eye so that no more than 5% of the stromal collagen in the irradiated spots undergoes clinically significant shrinkage as a result of the cornea reshaping procedure. The radiation source is configured to irradiate the spots on the cornea of the patient's eye through the heat sink so that depressions form at the spots and change a shape of the cornea. The controller is configured to determine the one or more treatment parameters by selecting one or more of: an irradiation wavelength, an irradiation power, a spot size, and a duration of irradiation. The heat sink is configured to prevent a corneal wound healing response from being triggered as a result of the cornea reshaping procedure and the controller is configured to determine the one or more treatment parameters so as to prevent permanent opacifications from forming in the cornea of the patient's eye.