Method and System for Combining OCT and Ray Tracing to Create an Optical Model for Achieving a Predictive Outcome
A system and method are provided for combining the imaging capabilities of an Optical Coherence Tomography (OCT) device with the calculated results of ray tracing techniques. The combination is then used to derive a predictive refractive outcome for an optical model. The resultant optical model includes diopter power and size information for use in preoperative planning (e.g. a capsulotomy) and/or for the manufacture of an Intraocular Lens (IOL).
1 . A method for creating an optical model for the propagation of light rays through a substantially transparent object which comprises the steps of:
scanning an imaging beam along a predetermined path through the object to obtain information about the spatial dimensions and the location of structures within the object;
using the information obtained in the scanning step to create an anatomical profile for the object;
selecting a start point, wherein the start point has a predetermined location in the object;
advancing a ray along a straight line segment in the object from the start point to an end point, wherein the line segment has a direction determined by a material derivative of the object at the start point and the line segment has a predetermined length;
designating the end point as a start point after the advancing step;
repeating the advancing step and the designating step to create a refraction profile for the object; and
combining the refraction profile with the anatomical profile to establish the optical model of the object.
2 . A method as recited in claim 1 further comprising the steps of:
changing the anatomical profile in the optical model;
recreating the refraction profile in the model based on the changing step; and
evaluating any refractive change indicated by the optical model in response to the changing step and the recreating step.
3 . A method as recited in claim 1 wherein the material derivative is an index of refraction of the structure at the start point.
4 . A method as recited in claim 1 further comprising the step of altering the derivative at the start point to account for properties of the ray wherein each property is selected from a group comprising intensity, wavelength, and polarization.
5 . A method as recited in claim 1 wherein the predetermined length of the straight line segment is less than 100 microns.
6 . A method as recited in claim 1 wherein the scanning step is accomplished by an Optical Coherence Tomography (OCT) device.
7 . A method as recited in claim 6 wherein the selecting step, the advancing step, the designating step and the repeating step are accomplished by a ray tracer.
8 . A method as recited in claim 7 wherein the OCT device and the ray tracer are controlled by a computer, wherein the combining step is accomplished by the computer, and further wherein the method is accomplished in accordance with a computer program run by the computer.
9 . A method as recited in claim 1 wherein the object is a crystalline lens of an eye.
10 . A method as recited in claim 1 wherein the optical model is used for the manufacture of an Intraocular Lens (IOL).
11 . A system for creating an optical model for the propagation of light rays through a substantially transparent object which comprises:
an Optical Coherence Tomography (OCT) device for creating an anatomical profile for the object;
a ray tracer for creating a refraction profile for the object; and
a computer/controller for combining the anatomical profile and the refraction profile to create the optical model of the object.
12 . A system as recited in claim 11 wherein control of the OCT device is accomplished by the computer/controller in accordance with a computer program comprising program sections for respectively scanning an imaging beam along a predetermined path through the object to obtain information about the spatial dimensions and the location of structures within the object, and using the information obtained in the scanning step to create the anatomical profile for the object.
13 . A system as recited in claim 11 wherein control of the ray tracer is accomplished by the computer/controller in accordance with a computer program comprising program sections for respectively selecting a start point having a predetermined location in the object, advancing a ray along a straight line segment in the object from the start point to an end point, designating the end point as a start point after advancing the ray, and repeating the advancing of the ray and the designating of the start point to create the refraction profile for the object, wherein the line segment has a direction from each start point determined by a material derivative of the object at the start point, and the line segment has a predetermined length.
14 . A system as recited in claim 11 wherein the computer/controller includes a computer program having program sections for combining the anatomical profile with the refraction profile to establish the optical model of the object; changing the anatomical profile in the optical model; recreating the refraction profile in the model; and evaluating any refractive change indicated by the optical model.
15 . A system as recited in claim 11 wherein the object is a crystalline lens of an eye and the optical model is used for the manufacture of an Intraocular Lens (IOL).
16 . A system for creating an optical model for the propagation of light rays through a substantially transparent object which comprises:
an imaging unit for scanning an imaging beam along a predetermined path through the object to create an anatomical profile of the object, wherein the anatomical profile includes spatial dimensions of the object and the location of structures within the object;
a ray tracer connected to the imaging unit for using the anatomical profile to uniquely identify a plurality of material derivatives at a plurality of respective, individually selected points in the object, and for calculating a ray segment at each selected point based on the material derivative of the object at the selected point, to create a refraction profile for the object based on the resultant plurality of ray segments; and
a computer connected to the imaging unit and to the ray tracer for combining the anatomical profile with the refraction profile to establish an optical model of the object.
17 . A system as recited in claim 16 wherein each ray segment has a direction and a length, and wherein the length is less than approximately 100 microns.
18 . A system as recited in claim 16 wherein each material derivative of the object includes factors pertinent to the object and are selected from a group comprising light propagation, reflectivity, and absorption characteristics of the object.
19 . A system as recited in claim 18 wherein the calculation of a ray segment includes consideration of light characteristics selected from a group comprising intensity, wavelength, and polarization.
20 . A system as recited in claim 16 wherein the anatomical model is selectively changed and the refraction profile is correspondingly recreated for evaluating any refractive changes caused by changing the anatomical profile.